CONSTRUCTION STANDARDS AND REGULATIONS

WATER SUPPLYWATER-DISTRIBUTION SYSTEMS AND STRUCTURES

SNiP 2.04.02-84OFFICIAL PUBLICATION

USSR STATE COMMITTEE FOR CONSTRUCTIONMOSCOW, 1985

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UDC 1.001.24 (083.75)

SNiP 2.04.02-84. Water Supply. Water-Distribution Systems and Structures [in Russian], USSR StateCommittee for Construction (USSR Gosstroi), Moscow, Stroiizdat Publishers, 1985, 136 [Russian] pages.

The document was prepared by the Soyuzvodokanalproyekt State Design Institute of USSRGosstroi (A. F. Britkin — topic supervisor; K. D. Semenov [Semyonov], A. Ye. Vysota, L. V. Yaroslavskii,and N. G. Yegorova); the All-Union Scientific Research Institute VODGYeO of USSR Gosstroi (V. V.Ashanin, candidate of technical sciences; E. M. Khokhlatov, candidate of technical sciences; A. A.Smirnov, candidate of technical sciences; L. F. Moshnin, doctor of technical sciences; and V. A. Gladkov,doctor of technical sciences); the Scientific Research Institute of Municipal Water Supply and WaterTreatment of the K. D. Pamfilov Academy of Municipal Services of the RSFSR Ministry of Housing andMunicipal Services (L. N. Paskutskaya, candidate of technical sciences, and M. P. Maizel’s, candidate oftechnical sciences); the Giprokommunvodokanal Design Institute of the RSFSR Ministry of Housing andMunicipal Services (V. A. Krasulin); the Central Scientific Research and Design Institute of Standard andExperimental Design of Engineering Equipment of Gosgrazhdanstroi [the State Committee for Civil Engi-neering and Architecture Under the State Committee for Construction of the USSR Council of Ministers](G. R. Rabinovich); the V. V. Kuibyshev Moscow Engineering and Construction Institute (V. S.Makagonov, candidate of technical sciences); the Soyuzgiprovodkhoz Design Institute of the USSRMinistry of Land Reclamation and Water Resources (N. O. Oganesov); the MosvodokanalNIIproyektInstitute of the Administration of Water-System and Sewage Services of the Moscow Municipal ExecutiveCommittee (V. A. Afanas’yev); the B. Ye. Vedeneyev VNIIG [All-Union Scientific Research Institute ofHydraulic Engineering] of the USSR Ministry of Power Engineering (I. I. Makarov, candidate of technicalsciences); the NIKTI GKh [expansion unknown] of the Ukrainian SSR Ministry of Housing and MunicipalServices (S. G. Kozhushko, candidate of technical sciences); the Donetsk PromstroiNIIproyekt of USSRGosstroi (S. A. Svetnitskii); the N. M. Gersevanov Scientific Research Institute of Foundations andUnderground Structures of USSR Gosstroi (V. G. Galitskii, candidate of technical sciences); theKrasnoyarsk PromstroiNIIproyekt of the USSR Ministry of Construction of Heavy-Industry Enterprises(V. F. Kardymon, candidate of technical sciences); and the M. T. Urazbayev Institute of the Mechanics andSeismic Resistance of Structures of the Uzbek SSR Academy of Sciences (G. Kh. Khokhmetov, doctor oftechnical sciences).

These Construction Standards and Regulations were put forth by the SoyuzvodokanalproyektDesign Institute of the USSR Gosstroi.

They have received consents from the USSR Ministry of Health, USSR Ministry of LandReclamation and Water Resources, USSR Ministry of Fishing Industry, Main Administration of FireProtection of the USSR Ministry of Internal Affairs, USSR Ministry of Railways, and RSFSR Ministry ofthe River Fleet.

They were prepared for approval by the Main Administration of Technical Standards Setting andStandardization of USSR Gosstroi.

Preparer: B. V. TAMBOVTSEV.Once SNiP [Construction Standards and Regulations] 2.04.02-84, “Water Supply. Water-

Distribution Systems and Structures,” are placed in effect, SNiP II-31-74, the chapter “Water Supply.Water-Distribution Systems and Structures” of SNiP II-31-74, becomes invalid.

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CORRECTIONS TO SNiP 2.04.02-84The Administration for Standardization and Technical Standards in Construction of USSR

Gosstroi hereby reports that SNiP 2.04.02-84, “Water Supply. Water-Distribution Systems andStructures,” contains the following typographical mistakes:In Table 43, in the column titled “Loads and Effects,” the values of the transient loads should be 10, 2.5,and 1 kPa instead of the printed values of 10, 2.5, and 0.1 MPa; andIn Paragraph 14.32 the values of the stresses should be 0.8 and 0.5 MPa instead of the printed values of0.08 and 0.05 MPa, respectively.

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CONTENTS PageCORRECTIONS TO SNiP 2.04.02-84 ........................................................................................................ii1. GENERAL.............................................................................................................................................12. DESIGN WATER CONSUMPTION AND FREE HEAD.......................................................................2

DESIGN WATER CONSUMPTION.............................................................................................2WATER CONSUMPTION FOR FIRE FIGHTING .......................................................................5FREE HEAD.................................................................................................................................10

3. WATER-SUPPLY SOURCES................................................................................................................104. WATER-SUPPLY PLANS AND SYSTEMS .........................................................................................125. WATER-INTAKE STRUCTURES ........................................................................................................15

GROUNDWATER-INTAKE STRUCTURES................................................................................15General Instructions ......................................................................................................................15Water-Intake Wells .......................................................................................................................15Dug Wells .....................................................................................................................................17Horizontal Water Intakes...............................................................................................................17Horizontal Filter Wells..................................................................................................................18Capping of Springs........................................................................................................................19Artificial Replenishment of Groundwater Reserves........................................................................19SURFACE WATER-INTAKE STRUCTURES..............................................................................20

6. WATER TREATMENT..........................................................................................................................26General Instructions ......................................................................................................................26CLARIFICATION AND DECOLORATION OF WATER ............................................................27General ..............................................................................................................................................................................................................................................................................................27Drum-Type Screen Filters .............................................................................................................27Reagent Use ..................................................................................................................................29MIXING DEVICES ......................................................................................................................32Air Separators ...............................................................................................................................32Flocculation Chambers..................................................................................................................33Vertical Settling Tanks..................................................................................................................35Horizontal Settling Tanks..............................................................................................................37Clarifiers with Suspended Sediment ..............................................................................................38Facilities for Clarification of Highly Turbid Water ........................................................................40Rapid Filters..................................................................................................................................41Coarse-grain Filters.......................................................................................................................45Contact Clarifiers ..........................................................................................................................46Slow Filters ...................................................................................................................................48Contact Prefilters...........................................................................................................................49WATER PURIFICATION.............................................................................................................47ELIMINATION OF ORGANIC SUBSTANCES, TASTES AND ODORS ....................................53STABILIZATION TREATMENT OF WATER AND TREATMENT WITH INHIBITORSTO ELIMINATE CORROSION OF STEEL AND CAST IRON PIPE...........................................53DEFERRIZATION OF WATER ...................................................................................................54FLUORINATION OF WATER .....................................................................................................55REMOVAL OF MANGANESE, FLUORINE AND HYDROGEN SULFIDE FROM WATER......55SOFTENING OF WATER............................................................................................................55FRESHENING AND DESALINATION OF WATER....................................................................56TREATMENT OF WASH WATER AND SEDIMENT FROM WATER TREATMENT PLANTS.....................................................................................................................................................56SUPPLEMENTARY ROOMS OF WATER TREATMENT PLANTS ...........................................55REAGENT AND FILTERING MATERIALS STORAGE.............................................................55HEIGHT OF PLACEMENT OF FACILITIES AT WATER TREATMENT PLANTS...................57

7. PUMPING PLANTS...............................................................................................................................60

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8. WATER LINES, WATER NETWORKS AND THEIR FACILITIES......................................................639. WATER STORAGE VESSELS ..............................................................................................................71

General Instructions ......................................................................................................................74Vessel Equipment..........................................................................................................................72Tanks ............................................................................................................................................76Water Towers................................................................................................................................76Fire Tanks and Bodies...................................................................................................................74

10. SANITARY PROTECTION ZONES ....................................................................................................75General Instructions ......................................................................................................................77BOUNDARIES OF SANITARY PROTECTION ZONES..............................................................78Surface Water Supply Sources .......................................................................................................78Underground Water Supply Sources ..............................................................................................79Sites of Water Line Facilities.........................................................................................................77Water Lines...................................................................................................................................80SANITARY MEASURES IN ZONES ...........................................................................................78Surface Water Supply Sources .......................................................................................................81Underground Water Supply Sources ..............................................................................................79Sites of Water Line Facilities.........................................................................................................82Water Lines...................................................................................................................................83

11. RECYCLED WATER COOLING SYSTEMS.......................................................................................80General Instructions ......................................................................................................................83WATER BALANCE IN SYSTEMS ..............................................................................................83PREVENTING MECHANICAL DEPOSITION ............................................................................82CONTROL OF “BLOOMING” OF WATER AND BIOLOGICAL OVERGROWTH....................82PREVENTING CARBONATE DEPOSITS...................................................................................85PREVENTING SULFATE DEPOSITS .........................................................................................83PREVENTING CORROSION.......................................................................................................86COOLING OF RECYCLED WATER ...........................................................................................84Cooling towers ..............................................................................................................................86Cooling Reservoirs ........................................................................................................................87Spray Pools ...................................................................................................................................91Placement of Cooling Units at Enterprise Sites..............................................................................88

12. EQUIPMENT, VALVES, AND PIPING ...............................................................................................9113. ELECTRICAL EQUIPMENT, PROCESS CONTROL, AUTOMATION, AND CONTROL SYSTEMS

93General Instructions ......................................................................................................................93Water Intake Facilities for Surface and Underground Water ..........................................................93Pumping Stations ..........................................................................................................................94Water Treatment Plants.................................................................................................................95Water Conduits and Water Pipeline Networks ...............................................................................96Water Storage Impoundment Facilities..........................................................................................96Circulating Water Supply Systems.................................................................................................94Control Systems ............................................................................................................................97

14. STRUCTURAL CONCEPTS AND STRUCTURES OF BUILDINGS AND FACILITIES.....................98The Master Plan ............................................................................................................................98Space-Planning Concepts ..............................................................................................................99Structures and Materials................................................................................................................101Structural Design ..........................................................................................................................104Anticorrosion Protection of Structural Members ............................................................................106Heating and Ventilation ................................................................................................................106

15. SUPPLEMENTARY REQUIREMENTS ON WATER SUPPLY SYSTEMS IN SPECIALNATURAL AND CLIMATIC CONDITIONS...............................................................................105SEISMIC REGIONS .....................................................................................................................108General Instructions ......................................................................................................................108

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Water Conduits and Networks .......................................................................................................109Structural Members.......................................................................................................................110UNDERWORKED LAND.............................................................................................................111General Instructions ......................................................................................................................111Water Conduits and Networks .......................................................................................................111Structural Members.......................................................................................................................112PERMAFROST.............................................................................................................................114General Instructions ......................................................................................................................114Water Conduits and Networks .......................................................................................................115Structural Members.......................................................................................................................117SUBSIDENCE-PRONE SOIL .......................................................................................................117General Instructions ......................................................................................................................117Water Conduits and Networks .......................................................................................................119Structural Members.......................................................................................................................121

APPENDIX 1. RECOMMENDED. METHODS OF DRILLING WATER INTAKE WELLS .............124APPENDIX 2. RECOMMENDED. REQUIREMENTS FOR WATER WELL FILTERS....................125APPENDIX 3. RECOMMENDED. TESTING AND MODE OBSERVATIONS

OF GROUNDWATER INTAKES.....................................................................................................127APPENDIX 4. RECOMMENDED. REMOVAL OF ORGANIC MATTER, TASTES AND ODORS.128APPENDIX 5. RECOMMENDED. STABILIZATION TREATMENT OF WATER, TREATMENT

WITH INHIBITORS TO PREVENT CORROSION OF STEEL AND CAST IRON PIPE...........130APPENDIX 6. RECOMMENDED. FLUORINATION OF WATER......................................................130APPENDIX 7. RECOMMENDED. SOFTENING OF WATER .............................................................132

Reagent Decarbonization and Lime-Soda Softening ......................................................................135Sodium-Cationite Method of Water Softening ...............................................................................136Hydrogen-Sodium-Cationite Method of Softening Water ...............................................................135

APPENDIX 8. RECOMMENDED. FRESHENING AND DESALINATION OF WATER...................140Ion Exchange ................................................................................................................................143Electrodialysis...............................................................................................................................141

APPENDIX 9. RECOMMENDED. PROCESSING OF WASH WATER AND SEDIMENTAT WATER TREATMENT PLANTS ..............................................................................................145

Wash Water Tanks........................................................................................................................145Wash Water Settling Tanks...........................................................................................................145Thickeners ....................................................................................................................................145Accumulators ................................................................................................................................146Freezing Sites................................................................................................................................148Drying Sites ..................................................................................................................................151

APPENDIX 10. OBLIGATORY. HYDRAULIC DESIGN OF PIPELINES ..........................................152APPENDIX 11. RECOMMENDED. TREATMENT OF COOLING WATER

WITH CHLORINE AND COPPER SULFATE................................................................................154APPENDIX 12. RECOMMENDED. DESIGN OF COOLING WATER TREATMENT MODES

TO PREVENT CARBONATE AND SULFATE DEPOSITS...........................................................155APPENDIX 13. RECOMMENDED. INTERIOR FINISH OF ROOMS ................................................159APPENDIX 14. RECOMMENDED. PATICULARS OF PLANNING WATER SUPPLY SYSTEMS…161

USSR State Committee for Construction Construction Standards and Regulations SNiP 2.04.02-84(USSR Gosstroi) Water Supply. External Systems and Structures Replacing SNiP II-31-74

These Standards must be observed in the design of centralized external permanent water-supplysystems of localities and economic entities.

In the preparation of water-supply plans, guidance shall be drawn from the Principles of WaterLegislation of the USSR and Union Republics, and also from requirements for nature conservation andnatural-resource management.

The fire-fighting requirements of these standards do not apply to the water systems of enterprisesthat produce, use, or store explosives, to lumber storage with a capacity of more than 10,000 m3, or tofacilities of the oil- and gas-producing and oil-refining industries, whose fire-fighting requirements are setby their respective regulatory documents.

1. GENERAL

1.1. Water supply to facilities must be designed on the basis of approved programs for thedevelopment and siting of sectors of the economy and branches of industry, programs for the developmentand siting of productive forces throughout Union republics, general, basin, and territorial programs forcomprehensive use and conservation of water, the general plans of cities and rural localities, and thegeneral plans of industrial centers.

During design, consideration must be given to the advisability of coordinating the operations of thewater-supply systems of facilities, regardless of their departmental affiliation.

Water-supply plans for facilities generally must be drawn up concurrently with sewage plans andwith mandatory analysis of the balance of water consumption and waste-water (sewage) disposal.

1.2. The designs for domestic-/drinking-water and combined industrial-/ drinking-water systemsmust provide for sanitary protection zones for water-supply sources, water-system structures, and waterlines.

1.3. The quality of water supplied for domestic and drinking needs must meet the requirements ofGOST [USSR State Standard] 2874-82.

Introduced bySoyuzvodokanalproyekt State Design Instituteof USSR Gosstroi

Approved by Decree No. 123of the USSR State Committee forConstruction of July 27, 1984

EffectivedateJanuary 1, 1985

Official publication

SNiP 2.04.02-84

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In the preparation, transportation, and storage of water used for domestic and drinking needs, useshall be made of reagents, internal antifriction coatings, and filter materials that meet the requirements ofthe Main Sanitation and Epidemiological Administration of the USSR Ministry of Health for use indomestic-/drinking-water-supply practice.

The quality of water supplied for industrial needs must meet technical requirements withconsideration for its effect on the products made and for providing the sanitary and hygienic conditionsnecessary for personnel.

The quality of water for irrigation or watering from a dedicated irrigation line or from industrialwater-distribution systems must meet the sanitary, hygienic, and agrotechnical requirements of the USSRMinistry of Health and the USSR Ministry of Agriculture.

1.4. The main technical decisions made in designs and the sequence in which they are implementedmust be substantiated through a comparison of the parameters of possible options. Feasibility calculationsshall be performed for those options whose advantages and drawbacks cannot be determined withoutcalculations.

The optimal scenario is determined by the smallest value of reduced costs with consideration forreduction of the costs of material resources, labor, electric power, and fuel.

1.5. Water-supply design shall provide for advanced technical decisions, the mechanization oflabor-intensive work, the automation of production processes, and maximum industrializationof construction and installation operations through the use of prefabricated structures,standard and model products and parts made at plants and in procurement workshops.

2. DESIGN WATER CONSUMPTION AND FREE HEAD DESIGN WATER CONSUMPTION

2.1. In the design of water-supply systems for localities, the specific average daily waterconsumption (over a year) for public domestic and drinking needs shall be adopted according to Table 1.

2.2. The design daily water consumption (average over a year) Qd-m (m3/day) for domestic anddrinking needs in an locality shall be determined from the equation:

Qd-m = ΣqfNf/1000, (1)where qf is the specific water consumption taken from Table 1, and Nf is the design number of inhabitantsin regions of housing development with different levels of services and amenities.

Table 1

Provision of amenities to regions with housing developmentSpecific average daily per-capita domestic-/drinking-water consumption in localities (overa year), L/day

Development with buildings equipped with indoorwater lines and sewage systems:

Without baths 125–160With baths & local water heaters 160–230With centralized hot-water supply 230–350

Notes:1. For developed regions with buildings with water use from standpipes, the specific average daily per-capita water consumption (over a year) shall be 30–50 L/day.2. The specific water consumption includes water consumption for domestic, drinking, and everyday needsin public buildings (by the classification adopted in SNiP [Construction Standards and Regulations] II-L.2-72*),with the exception of the water consumption at recreation buildings, sanatoria and tourist complexes, and pioneercamps, which shall be adopted according to SNiP II-30-76 and engineering data.3. Specific water consumption, within the limits set in Table 1, shall be chosen in relation to climaticconditions, the capacity of the water-supply source, water quality, the level of amenities, the number of stories instructures, and local conditions.

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4. The amount of water for the needs of industry supplying the populace with products andconsumption not allowed for may, when properly substantiated, be adopted on a supplemental basis inthe amount of 10–20% of total water consumption for domestic and drinking needs of the locality.5. For regions (microregions) developed with buildings with centralized hot-water supply, direct tapping ofhot water from the heat-distribution system shall be employed, at a daily average of 40% of total waterconsumption for domestic and drinking needs, and on the basis of per-hour maximum water withdrawal — 55% ofthis consumption. In the case of a mixed development, the size of the population living in the indicated buildingsshall be the basis for design.6. Specific water consumption in localities with more than 1 million residents may be increased, providedthat a substantiation is given in each specific case and consent is granted by state inspectorate authorities.

The design water consumption on days of maximum and minimum water consumption Qd (m3/day)shall be determined as follows:

Qd-max = Kd-maxQd-m; (2)Qd-min = Kd-minQd-m.

The coefficient Kd of daily nonuniformity of water consumption, which takes into account thelifestyle of the population, the operating conditions of enterprises, the extent to which buildings haveservices and amenities, and the variation of water consumption from season to season and by day of theweek, shall be assumed to be:

Kd-max = 1.1–1.3; Kd-min = 0.7–0.9.The design hourly water consumption qhr (m3/hr) shall be determined from the equations;

qhr-max = Khr-maxQd-max/24; (3)qhr-min = Khr-minQd-min/24.

The coefficient Khr of hourly nonuniformity of water consumption shall be determined from theexpressions:

Kh-max = αmaxβmax; (4)Kh-min = αminβmin.

where α is a coefficient that takes into account the level of services and amenities of buildings, theoperating conditions of enterprises, and other local conditions, assumed to be αmax = 1.2–1.4, αmin = 0.4–0.6; and β is a coefficient that takes into account the number of residents in an locality, as taken fromTable 2.

2.3. The water consumption for irrigation in localities and on the grounds of industrial enterprisesshall be taken from Table 3 on the basis of the coverage of the ground, the method of irrigation, the type ofplantations, and climatic and other local conditions.

2.4. Water consumption for domestic and drinking needs and for use in showers at industrialenterprises shall be determined according to the requirements of SNiP II-30-76 and SNiP II-90-81.

Here, the coefficient of hourly nonuniformity of water consumption for domestic and drinkingneeds at industrial enterprises shall be:2.5 for shops with heat release of more than 80 kJ (20 kcal) per m3/hr; and3 for other shops.

2.5. Water consumption for livestock, poultry, and animals uptake and watering at livestock-breeding farms and complexes shall be based on departmental regulatory documents of the USSR Ministryof Land Reclamation and Water Resources and the USSR Ministry of Agriculture.

2.6. Water consumption for the industrial needs of industrial and agricultural enterprises shall bedetermined on the basis of engineering data.

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Table 2Coeff. Number of residents (thousands)

up to0.1

0.15 0.2 0.3 0.5 0.75 1 1.5 2.5 4 6 10 20 50 100 300 1000ormore

βmax4.5 4 3.5 3 2.5 2.2 2 1.8 1.6 1.5 1.4 1.3 1.2 1.15 1.1 1.05 1

βmin0.01 0.01 0.02 0.03 0.05 0.07 0.1 0.1 0.1 0.2 0.25 0.4 0.5 0.6 0.7 0.85 1

Notes:1. In determining the water consumption for the design of structures, water pipelines, and the distributionmains, the coefficient β shall be adopted as a function of the number of residents serviced by them, or, in the caseof zonal water supply, as a function of the number of residents in each zone.2. The coefficient βmax shall be used when the pressure is determined at the exit from pumping stations orfrom the elevation of a water tower (or pressure reservoirs) necessary to provide the required free pressures (freehead) in the system during times of maximum water withdrawal on a day with peak water consumption, and thecoefficient βmin shall be used when the overpressures in the distribution system are determined for periods ofminimum water withdrawal on days of minimum water consumption.

Table 3Purpose of water Unit Water consumption

for irrigation (L/m2)Mechanical washing of pavements of thoroughfares and sites 1 wash 1.2–1.5Mechanical watering of paved thoroughfares and sites 1 watering 0.3–0.4Manual watering (with hoses) of pavements of sidewalks andthoroughfares

Same 0.4–0.5

Irrigation of municipal greenery Same 3–4Irrigation of lawns and flowerbeds Same 4–6Irrigation of plantations in earthen winter hothouses 1 day 15Irrigation of plantations in rack-type winter and earthenspring hothouses, greenhouses of all types, and warmed earth

Same 6

Irrigation of plantations on personal plots of:Vegetable cropsFruit trees

SameSame

3–1510–15

Notes:1. In the absence of data on sites concerning the types of services and amenities (green plantations, thor-oughfares, etc.), the specific average daily water consumption over the watering season for irrigation per residentshall be set at 50–90 L/day, depending on climatic conditions, power, source of water supply, level of services andamenities in localities, and other local conditions.2. The number of irrigation sessions shall be set at 1–2/day, depending on climatic conditions.

2.7. The distribution of water consumption by time of day in localities and at industrial andagricultural enterprises shall be based on the design water-consumption schedules.

2.8. In putting together design schedules, the technical decisions made in the plan to eliminate thecoincidence in time of the maximum water withdrawals from the distribution system for various needs shallbe taken as the starting point (placement of control tanks replenished according to a preset schedule at largeindustrial enterprises, water supply for watering the grounds and for filling irrigation machines from specialcontrol tanks or through devices that cut off water supply as free head decreases to the preset limit, etc.).

The design schedules for water withdrawals for various needs that are made from the distributionsystem without the specified monitoring shall be made to coincide in time with the schedules of domestic-/drinking-water consumption.

2.9. If concentrated consumption needs to be taken into account, the specific water consumptionfor determining water consumption at individual residential and public buildings shall be adopted to complywith the requirements of SNiP II-30-76.

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2.10. During the drafting of water-supply sections of the water-use programs, regional plans, andgeneral plans specified in Paragraph 1.1, the specific average daily water consumption (over a year) maybe taken from Table 4.

Table 4Water consumer Specific average per-capita daily water consumption (over a

year) in populated areas (l/day)up until 1990 up until 2000

Cities 550 600Rural populated areas 125 150

Notes:1. Specific water consumption includes water consumption for domestic and drinking needs in residentialand public buildings, the needs of local industry, watering of streets, and watering of greenery.2. Specific water consumption may be changed by ±10–20%, depending on climatic and other localconditions and on the level of services and amenities.3. For the southern regions, the water balance shall take into account additional water consumption forwatering of greenery and private plots from the irrigation-ditch network.4. In the absence of data on the development of industry, it is permitted to adopt additional water con-sumption for the needs of enterprises that draw water from the domestic-/drinking-water distribution systems of anlocality, in an amount of up to 25% of water consumption as determined from the specific water consumptiongiven in Table 4.

Water consumption for the needs of industrial and agricultural enterprises shall be determined onthe basis of consolidated standards of the USSR Ministry of Land Reclamation and Water Resources andthe USSR Ministry of Agriculture or, if none exists, on the basis of similar designs.

WATER CONSUMPTION FOR FIRE FIGHTING

2.11. A fire main shall be provided in localities and at economic entities, and generally shall becombined with the domestic-/drinking-water main or an industrial main.Notes:

1. It is permitted to use external fire-fighting water supply from tanks (reservoirs, water bodies) withconsideration for the requirements of paragraphs 9.27–9.33 for:• Localities with up to 5000 residents;• Freestanding public buildings up to 1000 m3 in volume located in localities that do not have a loop-type firemain;• Industrial buildings with production facilities of categories C, D, and E when water consumption for outside firefighting is 10 L/sec;• Coarse-feed storage facilities up to 1000 m3 in volume;• Warehouses for mineral fertilizers, with buildings up to 5000 m3 in volume;• Buildings of radio and television stations; and• Buildings of refrigeration plants and fruit and vegetable storage sites.

2. Fire-fighting water supply does not have to be provided for:• Localities with up to 50 residents, where there are buildings up to two stories tall;• Freestanding public dining facilities (diners, snackbars, cafes, etc.) located outside localities, where the volumeof the buildings is up to 1000 m3, and trade businesses with an area of up to 150 m2 (excluding stores sellingindustrial goods), as well as public buildings with fire-resistance ratings I and II up to 250 m3 in volume that arelocated in localities;• Industrial buildings of fire-resistance ratings I and II up to 1000 m3 in volume (excluding buildings withmetallic unprotected or wood load-bearing structures, and also those with polymeric warmth-keeping insulation upto 250 m3 in volume) with production facilities of category E;

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• Plants that make reinforced-concrete products and commercial concrete with buildings of fire-resistance ratings Iand II that are located in localities equipped with water-distribution systems, provided that hydrants are located ata distance of no more than 200 m from the most distant building of the plant;• Seasonal general-purpose receiving and procurement stations for agricultural products, where the buildings havea volume of up to 1000 m3; and• Storehouses for combustible and noncombustible materials in combustible packaging, that are up to 50 m2 inarea.

2.12. Water consumption for outside fire fighting (for one fire) and the number of simultaneousfires in an locality for the purpose of designing water-distribution system mains (design loop-type lines)shall be taken from Table 5.

Table 5Water consumption (L/sec) per fire for

outside fire fighting in an localityNumber of residents in

locality (thous.)Design number ofsimultaneous fires

Development with build-ings up to 2 stories high,inclusively, regardless of

fire-resistance rating

Development withbuildings 3 stories highor taller, regardless offire-resistance rating

≤1 1 5 10>1, ≤5 1 10 10>5, ≤10 1 10 15

>10, ≤25 2 10 15>25, ≤50 2 20 25>50, ≤100 2 25 35

>100, ≤200 3 — 40>200, ≤300 3 — 55>300, ≤400 3 — 70>400, ≤500 3 — 80>500, ≤600 3 — 85>600, ≤700 3 — 90>700, ≤800 3 — 95>800, ≤1000 3 — 100

Notes:1. Water consumption for outside fire fighting in a locality must not be smaller than water con-sumption for fire fighting in the residential and public buildings specified in Table 6.2. In zonal water supply, water consumption for outside fire fighting and the number of simultaneous fires ineach zone must be determined as a function of the number of residents living in the zone.3. The number of simultaneous fires and the water consumption per fire in localities with more than 1million persons shall be based on the requirements of State Fire Inspectorate authorities.4. For a “cluster” water pipeline, the number of simultaneous fires shall be based on the total number ofresidents in the localities connected to the water pipeline.

The water consumption to make up the volume consumed to fight fires from a cluster water pipeline shallbe determined as the sum of the water consumption for each of the localities (and accordingly the number ofsimultaneous fires) that require the largest water consumption for fire fighting according to paragraphs 2.24 and2.25.5. The design number of simultaneous fires in a locality includes fires at industrial enterprises locatedwithin the locality. The design water consumption here shall include the corresponding water consumption for firefighting at these enterprises, but shall be no lower than the figures specified in Table 5.

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2.13 Water consumption for outside fire fighting (for one fire) in residential and publicbuildings for the purpose of designing connecting and distribution lines of a water-distribution system, aswell as a water-distribution system inside a microregion or block, shall be the same as for the building thatrequires the largest water consumption, per Table 6.

Table 6Building description Water consumption (L/sec) per fire for outside fire fighting in residential

and public buildings, regardless of fire-resistance ratings for the followingbuilding volumes (thous. m3)

≤≤≤≤1 >1, ≤≤≤≤5 >5, ≤≤≤≤25 >25, ≤≤≤≤50 >50, ≤≤≤≤150Single-compartment &multicompartment build-ings with . . . floors:

≤2 10* 10 — — —>2, ≤12 10 15 15 20 —>12, ≤16 — — 20 25 —>16, ≤25 — — — 25 30

Public buildings with . . .floors:

≤2 10* 10 15 — —>2, ≤6 10 15 20 25 30>6, ≤12 — — 25 30 35>12, ≤16 — — — 30 35

* For rural localities, the water consumption per fire is 5 L/sec.Note: The water consumption for fire fighting in buildings with a height or volume greater than those specified inTable 6, and also in public buildings with a volume greater than 25,000 m3 with high occupancy (entertainmentcenters, trade centers, department stores, etc.) shall be adopted and consented to through the prescribedprocedure.

Table 7Fire-resistancerating ofbuilding

Fire-safetycategory ofproductionoperations

Water consumption for outside fire fighting in industrial buildings with lanterns (skylights),and also in buildings without lanterns (skylights) that are up to 60 m wide, per fire (L/sec)for the following building volumes (thous. m3)

≤≤≤≤3 >3, ≤≤≤≤5 >5, ≤≤≤≤20 >20, ≤≤≤≤50 >50, ≤≤≤≤200 >200,≤≤≤≤400

>400,≤≤≤≤600

I & II D, E, F 10 10 10 10 15 20 25I & II A, B, C 10 10 15 20 30 35 40III D, E 10 10 15 25 35 — —III C 10 15 20 30 40 — —IV & V D, E 10 15 20 30 — — —IV & V C 15 20 25 40 — — —

2.14. Water consumption for outside fire fighting at industrial and agricultural enterprises for onefire shall be the same as for the building that requires the largest water consumption per Table 7 or 8.

Table 8Fire-resistancerating ofbuildings

Fire-hazardcategory ofproduction

Water consumption (L/sec) for outside fire fighting in industrial buildings without lanterns(skylights) 60 m wide or wider per fire for the following building volumes (thous. m4 [sic])

≤≤≤≤50 >50,≤≤≤≤100

>100,≤≤≤≤200

>200,≤≤≤≤300

>300,≤≤≤≤400

>40,≤≤≤≤500

>500,≤≤≤≤600

>600,≤≤≤≤700

>70,≤≤≤≤800

I & II A, B, C 20 30 40 50 60 70 80 90 100I & II D, E, F 10 15 20 25 30 35 40 45 50

Notes to Tables 7 and 8:

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1. In the event that there are two design fires at an enterprise, the design water consumption for fire fightingshall be based on the two buildings that require the largest water consumption.2. Water consumption for outside fire fighting in freestanding ancillary buildings of industrial enterprisesshall be determined from Table 6 in the same way as it would be for public buildings, while the water consumptionfor enterprises built into industrial buildings shall be determined from the total building volume by using Table 7.3. Water consumption for outside fire fighting at buildings of agricultural enterprises with fire-resistanceratings of I and II and a volume not exceeding 5000 m3 with production facilities of categories D and E shall be5 L/sec.4. Water consumption for outside fire fighting in lumber storage facilities with a capacity of up to 10,000 m3

shall be taken from Table 7, in which they shall be classified as buildings with a fire-resistance rating of V andproduction of category C. If the capacity of the storage facilities is larger, guidance shall be taken from therequirements of the applicable regulatory documents.5. Regardless of the building volume and the number of people who live in the village, water consumptionfor outside fire fighting in buildings of radio and television stations shall be at least 15 L/sec unless a larger waterconsumption is required by Tables 7 and 8.

The aforementioned requirements do not apply to radio and television relay stations installed at existingcommunications facilities and communications facilities under design.6. Water consumption for outside fire fighting at buildings with volumes greater than those specified inTables 7 and 8 shall be set in conjunction with territorial State Fire Inspectorate authorities.7. The fire-resistance rating of buildings or structures shall be determined according to the requirements ofSNiP II-2-80, and the category of production facilities with respect to explosion, explosion-and-fire, and firehazard shall be determined per SNiP II-90-81.8. For buildings with a fire-resistance rating of II with wooden structures, water consumption for outsidefire fighting shall be 5 L/sec greater than the value indicated in Table 7 or 8.

2.15. Water consumption for outside fire fighting in buildings partitioned by fire walls shall bebased on that part of the building where the largest water consumption is required.

Water consumption for outside fire fighting in buildings divided by firebreak partitions shall bedetermined from the total building volume and the higher fire-hazard production category.

2.16. Water consumption for outside fire fighting in one- and two-story industrial buildings andone-story warehouse buildings no more than 18 m high (from the floor to the bottom of horizontal load-bearing structures on a support) with load-bearing steel structures (with a fire-resistance period of at least0.25 hr) and enclosing structures (walls and ceilings) made of shaped steel or asbestos-cement sheet withcombustible or polymeric warmth-keeping coverings shall be 10 L/sec more than the values given in Tables8 and 7.

For these buildings dry standpipes 80 mm in diameter that are equipped with connecting fire headson the top and bottom ends of the standpipe shall be provided at the locations of outside fire stairs.Note: For buildings no more than 24 m wide and with a height of no more than 10 m to the cornice, drystandpipes do not have to be provided.

2.17. Water consumption for outside fire fighting in open storage sites for containers holding up to5 metric tons of cargo shall be as follows:15 L/sec for 30–50 containers;20 L/sec for more than 50 to 100 containers;25 L/sec for more than 100 to 300 containers; and40 L/sec for more than 300 to 1000 containers.

2.18. Water consumption for fire fighting when there is a combined water line for sprinkler ordrencher installations, indoor fire cocks, and outdoor hydrants for 1 hr from the time of the start of firefighting shall be taken as the sum of the maximum consumption figures determined per the requirements ofthe “Instructions on the Design of Automatic Fire-Extinguishing Installations,” SNiP II-30-76, and thissection.

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The water consumption necessary during fire fighting after the sprinkler or drencher installationsare shut off shall comply with paragraphs 2.14, 2.16, 2.20, and 2.21.Note: The simultaneous operation of sprinkler and drencher installations shall be taken into consideration inrelation to fire-fighting conditions.

2.19. Water consumption for outside fire fighting with foam units, units with water cannon, or byspraying water shall be determined according to fire-safety requirements set forth in the standards for theconstruction design of enterprises, buildings, and structures of the corresponding branches of industry, withconsideration for additional water consumption in the amount of 25% from hydrants per Paragraph 2.14.Here, total water consumption shall be no less than the consumption determined from Table 7 or 8.

2.20. For fire fighting in buildings equipped with indoor fire cocks, allowance shall be made foradditional water consumption beyond the consumption levels given in Tables 5–8, which should be used forbuildings that require the largest water consumption according to the requirements of SNiP II-30-76.

2.21. The design water consumption for fire fighting shall be assured at the maximum waterconsumption for other needs specified in Paragraph 4.3; here, at an industrial enterprise water consumptionfor watering the grounds, taking of showers, washing of floors, washing of production equipment, andwatering of plants in hothouses shall not be take into account.

In cases where, because of the conditions of the production process, partial use of industrial waterfor fire fighting is possible, hydrants on the industrial water-distribution system shall be installed inaddition to hydrants installed on the fire-fighting water system supplying the required water flow for firefighting.

2.22. The design number of simultaneous fires at an industrial or agricultural enterprise shall beadopted as a function of the area they occupy: one fire for an area of up to 150 hectares, and two fires foran area greater than 150 hectares.

2.23. When there is a combined fire-fighting water pipeline for an locality and an industrial oragricultural enterprise located outside the locality, the design number of simultaneous fires shall be asfollows, according to the requirements of the Main Administration of Fire Protection of the USSR Ministryof Internal Affairs:If the area of the grounds of the enterprise is up to 150 hectares and the number of residents in the localityis up to 10,000 — one fire (at the enterprise or in the locality with the largest water consumption); the samesituation, but with more than 10,000 to 25,000 residents in the locality — two fires (one at the enterpriseand one in the locality);If the area of the grounds of the enterprise is greater than 150 hectares and the number of residents in thelocality is up to 25,000 — two fires (two at the enterprise or two in the locality with the largest con-sumption);If the number of residents in the locality is greater than 25,000 — according to Paragraph 2.22 and Table5; here, the water consumption shall be determined as the sum of the required larger consumption (at theenterprise or in the locality) and 50% of the required smaller consumption (at the enterprise or in thelocality); andIf there are several industrial enterprises and one locality — according to the requirements of State FireInspectorate authorities.

2.24. The fire-fighting time shall be assumed to be 3 hr; for buildings with fire-resistance ratingsof I and II, with incombustible load-bearing structures and insulation and with production facilities ofcategories D and E the fire-fighting time shall be 2 hr.

2.25. The maximum time to restore the water volume used in fighting a fire shall not exceed:24 hr in localities and at industrial enterprises with production facilities with fire hazard of categories A, B,and C;36 hr at industrial enterprises with production facilities with fire hazard of categories D, E, and F; or72 hr in rural localities and at agricultural enterprises.Notes:

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1. For industrial enterprises with water consumption for outside fire fighting of 20 L/sec or less, it ispermitted to increase the recovery time for the water volume used in fire fighting:— To 48 hr — for production facilities of categories D, E, and F; and— To 36 hr — for production facilities of category C.

2. For the time period needed to restore the volume of water used in fire fighting, it is permitted toreduce water supply for domestic and drinking needs by category I and II water-supply systems to 70% of thedesign consumption and by category III water-supply systems to 50%, and to reduce water supply for industrialneeds to the emergency schedule.

FREE HEAD

2.26. The minimum free head in the water-distribution system of an locality at maximumdomestic-/drinking-water consumption at the entry to a building above ground level shall be the same as ifwere a single-story development at least 10 m high; if the number of stories is greater, 4 m shall be addedfor each floor.Notes:

1. During the hours of minimum water consumption, the head to each floor except the ground floor maybe assumed to be 3 m; in this case, water must be delivered to tanks for storage.

2. For individual multistory buildings or groups thereof that are located in areas where development hassmaller number of stories, or on elevated sites, it is permitted to provide local pumping units to increase the head.

3. The free head in the distribution system at water posts shall be at least 10 m.2.27. The free head in an outside industrial water-pipeline system shall be based on engineering

data.2.28. The free head at the consumers in an outside domestic-/drinking-water distribution system

must not exceed 60 m.If the head in the system exceeds 60 m, installation of pressure regulators or zoning of the water-

supply system shall be provided for individual buildings or regions.2.29. The fire-fighting water pipeline shall be of the low-pressure type; a high-pressure fire-

fighting water pipeline may be used with proper substantiation.In a high-pressure water pipeline, fixed fire pumps shall be equipped with units that ensure that the

pumps start up no later than 5 min after the signal of a fire outbreak is issued.Note: For localities with up to 5000 residents where there is no professional fire department, the fire-fightingwater pipeline shall be of the high-pressure type.

2.30. The free head in a low-pressure fire-fighting water-pipeline system (at ground level) duringfire fighting shall be at least 10 m.

The free head in a high-pressure fire-fighting water-pipeline system shall provide a compact jet atleast 10 m high during the entire duration of water flow for fire fighting and with the fire-fighting barrel atthe level of the highest point of the tallest building.

The maximum free head in a combined water-pipeline system shall not exceed 60 m.

3. WATER-SUPPLY SOURCES

3.1. The selection of a water-supply source shall be substantiated by the results of topographic,hydrologic, hydrogeologic, ichthyological, hydrochemical, hydrobiological, hydrothermal, and othersurveys and sanitary inspections.

3.2. Watercourses (rivers, canals), water bodies (lakes, reservoirs, ponds), seas, ground water(aquifers, infrabed water, mine water, and other water) shall be considered as water-supply sources.

For industrial water supply to industrial enterprises, the possibility of using treated waste water(sewage) shall be considered.

Reservoirs fed by water from natural surface sources may be used as a water-supply source.

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Note: In a water-supply system it is permitted to use several sources with different hydrologic and hydrogeologiccharacteristics.

3.3. The selection of a domestic-/drinking-water-supply source shall be made in compliance withthe requirements of GOST 17.1.3.0[missing]77, as revised.

The selection of an industrial-water-supply source shall be made with consideration for consumers’water-quality requirements.

The water-supply sources accepted for use shall go through the consent process in accordance withthe “Instructions on the Procedure for Obtaining Consents for and Issuing Permits for Special Water Use”of the USSR Ministry of Land Reclamation and Water Resources.

3.4. For domestic-/drinking-water pipelines, maximum use shall be made of available groundwaterresources that meet sanitation and hygienic requirements.

If there are insufficient operational reserves of natural ground water, the possibility of increasingthem through artificial replenishment shall be considered.

3.5. The use of drinking-quality ground water for needs unrelated to domestic-/drinking-watersupply generally is not allowed. In regions where the necessary surface water sources are unavailable andthere are adequate reserves of drinking-quality ground water, it is permitted to use this water for industrialand irrigation (watering) needs with the permission of water-management and -conservation agencies.

3.6. For industrial- and domestic-/drinking-water supply the use of mineralized and geothermalwater is permitted, provided that the water is treated properly and that sanitation requirements areobserved.

3.7. The supply of average monthly water consumption from surface sources shall be based onTable 9, depending on the category of the water-supply system, as determined from Paragraph 4.4.

Table 9Category of water-supply

systemSupply (%) of minimum average monthly water con-

sumption from surface sourcesI 95II 90III 85

3.8. In evaluating the use of water resources for water-supply purposes, the following shall betaken into consideration:

• The consumption (flow) regime and the water balance of the source, with a 15–20-yearforecast;

• Consumers’ requirements for water quality;• The qualitative characteristics of the water at the source, with a specific breakdown of the

corrosiveness of the water, and a forecast of the possible change in its quality withconsideration for the inflow of waste water;

• The qualitative and quantitative characteristics of sediments and small trash, their regimes, themovement of bottom sediments, and shore and bank stability;

• The presence of permafrost, the possibility of freezing and drying-up of the source, and thepresence of snow avalanches and mudflows (on mountain watercourses) and of other naturalphenomena in the watershed basin of the source;

• The fall and winter regime of the source, and the nature of slush-ice phenomena in it;• The water temperature by month of the year, and the development of phytoplankton at various

depths;

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• The characteristic features of the spring opening of the source and of high waters (forwatercourses on plains), and the behavior of the spring–summer high waters (for mountainwatercourses);

• Groundwater reserves and alimentation conditions, as well as the possible disruption thereof asa result of the change in natural conditions, the building of water reservoirs or drainage,artificial water pumping, and so forth;

• Groundwater quality and temperature;• The possibility of artificial replenishment and formation of groundwater reserves; and• The requirements of water-management and -conservation agencies, the sanitation and

epidemiology service, fish-conservation authorities, and so forth.3.9. In evaluating the adequacy of water resources of surface water-supply sources, below the

point where water is drawn the guaranteed water flow needed in each season of the year must be providedto satisfy the water needs of downstream localities, industrial, agricultural, fishing, and navigationalenterprises, and other types of water use, and also to meet sanitation requirements for water-supply sourceconservation.

3.10. If there is inadequate water flow in the surface source, provision shall be made for regulationof the natural water discharge within a single hydrologic year (seasonal regulation) or a multiyear period(long-term regulation), as well as transfer of water from other surface sources with more abundant water.Note: If available water flows at the source are inadequate and increasing them is difficult or entails a high cost,the extent of the necessary supply to individual water consumers shall be determined in conjunction with agenciesof the republic’s Ministry of Land Reclamation and Water Resources, as well as agencies of the sanitation andepidemiology service.

3.11. Groundwater resources shall be evaluated on the basis of data from hydrogeologic surveys,exploration, and studies in accordance with the “Classification of Operational Reserves and ForecastGroundwater Resources” and the “Instructions on the Use of Classified Groundwater Reserves forFreshwater Deposits” of the State Commission for Mineral Reserves under the USSR Council of Ministers.

Groundwater reserves shall be approved by the state or territorial commission for mineral reserves.The approval of operational groundwater reserves is not required if capital investments in building

water-intake structures do not exceed 500,000 rubles, or 1 million rubles in the case of rail-transportfacilities.

Here, the cost of water-intake structures shall take into account the costs of water-intake devices,pumping stations, water-treatment works, reservoirs, and water lines to the consumer.

4. WATER-SUPPLY PLANS AND SYSTEMS

4.1. A water-supply plan and system shall be selected on the basis of a comparison of possibleoptions for implementing them with consideration for the particulars of the facility or group of facilities, therequired water consumption in different phases of their development, water-supply sources, andrequirements for water pressure, water quality, and the assuredness of water supply.

4.2. The comparison of options shall substantiate:• Water-supply sources and the use of them for various consumers;• The degree of centralization of the system, and the advisability of setting aside local water-

supply systems;• The combination or separation of structures, water lines, and distribution systems intended for

various purposes;• Zonation of the water-supply system, use of regulating reservoirs, and the use of regulating

stations and booster pumping stations;• The use of combined or local circulating water-supply systems;

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• The use of spent water from some enterprises (shops, installations, process lines) for theindustrial needs of other enterprises (shops, installations, process lines), and also for wateringof grounds and greenery;

• The use of treated industrial waste water and household sewage, as well as the accumulatedsurface runoff for industrial water supply, irrigation, and flooding of water bodies;

• The advisability of setting up closed cycles or creating closed water-use systems; and• The sequence of the construction and startup of components of the system, on the basis of

startup complexes.4.3. Depending on local conditions and the water-supply plan adopted, the centralized water-

supply system of localities shall support:• Domestic-/drinking-water consumption in residential and public buildings, and the needs of

municipal-utility and consumer-service enterprises;• Domestic-/drinking-water consumption at enterprises;• The industrial needs of industrial and agricultural enterprises where drinking-quality water is

needed or for which it is economically inadvisable to build a separate water pipeline;• Fire fighting; and• The internal needs of water-treatment stations, flushing of water-pipeline and sewage

networks, and so forth.With proper grounds, it is permissible to set up an independent water pipeline for:

Irrigation and washing of grounds (streets, thoroughfares, sites, greenery), the operation of fountains, andso forth;The watering of plantations in hothouses and greenhouses and on open parcels, and also in private plots.

4.4. In terms of assuredness of water supply, centralized water-supply systems are subdivided intothree categories, as given below.

Category I — it is permitted for water supply for domestic and drinking needs to decrease by nomore than 30% of design consumption and for industrial needs to the limit set in the emergency operatingschedules of enterprises; the length of the decrease in supply must not exceed 3 days. An interruption inwater supply or a decrease in supply below the specified limit is allowed for the duration of the shutoff ofdamaged system components and for the length of the time for which backup system components areengaged (equipment, fittings, structures, piping, etc.), but for no more than 10 min.

Category II — the magnitude of the permissible decrease in water supply is the same as forCategory I; the duration of a decrease in supply must not exceed 10 days. An interruption in water supplyor a decrease in supply below the specified limit is allowed for the duration of the shutoff of damaged com-ponents and for the length of the time for which backup components are engaged or during which repairsare being carried out, but for no more than 6 hr.

Category III — the magnitude of the permissible decrease in water supply is the same as forCategory I; the length of a decrease in supply must not exceed 15 days. An interruption in water supply ora decrease in supply below the specified limit is permitted for the time necessary to perform repairs, but forno more than 24 hr.

Combined domestic-/drinking-water and industrial water pipelines of localities where there aremore than 50,000 residents shall be assigned to Category I; those where there are from 5000 to 50,000shall be placed in Category II; and those with fewer than 5000 shall be placed in Category III.

The category of agricultural cluster water pipelines shall be based on the locality with the largestnumber of residents.

If the assuredness of water supply for the industrial needs of industrial and agricultural enterprises(production facilities, shops, installations) needs to be increased, local water-supply systems shall beprovided.

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Designs of local systems that meet the engineering requirements of facilities shall be consideredand approved in conjunction with the designs of these facilities.

The category of individual components of water-supply systems shall be determined in relation totheir functional significance in the overall water-supply system.

The components of Category II water-supply systems damage to which may disrupt water supplyfor fire fighting shall be placed in Category I.

4.5. During the development of a water-supply plan and system, technical, economic, andsanitation evaluations of existing works, water pipelines, and distribution systems shall be provided, andthe extent of their future use shall be substantiated with consideration for the costs of rebuilding them andintensifying their operation.

4.6. Water-supply systems that meet fire-fighting needs shall be designed according to theinstructions in Section 2.

4.7. Circulating water-supply systems shall be designed according to the instructions inSection 11.

4.8. In the selection of the optimal version of industrial water-supply systems, when necessary thepossibility and advisability shall be considered of making changes in production processes in which theincrease in basic production costs turns out to be smaller than the decrease in the reduced cost of water-supply and sewage systems.

4.9. Water-intake works, water pipelines, and water-treatment stations generally shall be designedfor the average hourly consumption on the day of peak water consumption.

4.10. Analyses of the joint operation of water pipelines, water-pipeline distribution systems,pumping stations, and regulating tanks shall be performed to the extent necessary to substantiate the water-supply and -distribution system for the design period, to determine its implementation sequence, to selectpumping equipment, and to determine the required volumes of regulating tanks and their locations for eachphase of construction.

4.11. For water-supply systems of localities, analyses of the joint operation of water pipelines,water-pipeline distribution systems, pumping stations, and regulating tanks generally shall be performed forthe following typical regimes of water supply:On the day of peak water consumption — the maximum, average, and minimum hourly consumption, aswell as the maximum hourly consumption and design water consumption for fire fighting;On days of average water consumption — the average hourly consumption;On days of minimum water consumption — the minimum hourly consumption.

Performing analyses for other water-consumption regimes and refusal to perform analyses for oneor several of the indicated regimes are allowed if the adequacy of the analyses performed to determine theconditions of joint operation of water pipelines, pumping stations, regulating tanks, and distributionsystems for all specific water-consumption regimes is substantiated.

For industrial water-supply systems, the typical operating conditions shall be determined accordingto the specifics of production processes and with a view to ensuring fire safety.Note: The analysis of structures, water pipelines, and distribution systems for a fire-fighting period shall not takeinto account the emergency shutoff of water pipelines and lines of circular systems, or of sections and blocks ofstructures.

4.12. During the drafting of a water-supply plan, a list shall be prepared of the parameters thatneed to be monitored for a later systematic check by operating personnel as to whether actual waterconsumption, coefficients of nonuniformity of water consumption, and the actual characteristics of equip-ment, structures, and devices conform with the plan. The corresponding sections of the plan shall providefor the installation of the devices and apparatus necessary to perform monitoring.

4.13. During the drafting of agricultural water-supply plans and the development of agriculturalwater-supply systems, the following shall be done:

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• Centralized water-supply systems shall be designed only for prospective localities andagricultural production facilities;

• For rural localities that are to be preserved for the design period, provision shall be made forrebuilding of existing water-intake works (water-intake wells, dug wells, tapping of springs,etc.) with equipment for mechanical water lifts, and for the construction of interior water linesin individual cultural, consumer-services, and industrial buildings;

• During construction of cluster water pipelines, provision shall be made for measures topreserve water quality during transportation of the water over large distances, especially in theinitial operating period of these systems, when the speeds of the water in the lines areconsiderably below design values;

• Consideration shall be given to the advisability of setting up individual seasonal water lines forirrigation of private parcels, by using local sources and irrigation systems that are unsuitableas sources for domestic-/drinking-water supply; and

• During the design of water-supply systems for regions where saline water is found, in theabsence of local sources of fresh water consideration shall be given to the advisability of usingdemineralized water for drinking needs and of mineralized water for nondrinking needs. In thiscase, for villages with single-story structures it is recommended that interior water lines bedesigned only for supply of mineralized water, with demineralized water supplied for drinkingneeds through water posts.

5. WATER-INTAKE STRUCTURES

GROUNDWATER-INTAKE STRUCTURESGeneral Instructions

5.1. The selection of the type of water-intake structures and the site plan for them shall be basedon the geological, hydrogeologic, and sanitation conditions of the region.

5.2. The design of new water intakes and the expansion of existing ones shall take into account theconditions of their interaction with existing and planned water intakes in adjacent sectors, and also for theirenvironmental impact (surface runoff, vegetation, etc.).

5.3. Groundwater intakes shall use the following water-intake structures: water-intake wells, dugwells, horizontal water intakes, combined water intakes, horizontal filter wells, and tapping of springs.Water-Intake Wells

5.4. Well designs shall specify the drilling method and the structures of the well, its depth, casingdiameters, the type of water-intake section, the water lift and wellhead, and the test procedure for them.

5.5. Well-drilling methods are presented in recommended Appendix 1.5.6. Well designs (structures) shall provide for the possibility of making flow-rate and water-level

measurements, performing water sampling, and carrying out repairs and restoration work by using pulsed,reagent, and combined methods of regeneration during well operation.

5.7. The diameter of the production string in wells shall be as follows: when pumps with anelectric motor above the well are installed — 50 mm larger than the nominal pump diameter; and whenpumps with a submersible electric motor are used it shall be equal to the nominal pump diameter.

5.8. Depending on local conditions and wellhead equipment, wells generally shall be placed in anaboveground wellhouse or an underground chamber.

5.9. The dimensions of the wellhouse or underground chamber in plan shall be based on thepositioning within it of the electric motor, electrical equipment, and instrumentation.

The height of an aboveground wellhouse or underground chamber shall be based on the size of theequipment, but shall be at least 2.4 m.

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5.10. The top part of the production string shall protrude at least 0.5 m above the floor.5.11. The design of the wellhead shall allow complete sealing that will prevent surface water and

contaminants from making their way into the drillstring–casing annulus and the casing–borehole annulus.5.12. Provision shall be made for installation and dismounting of sections of downhole pumps

through hatches located above the wellhead, by using mechanical gear.5.13. The number of backup wells shall be taken from Table 10.

Table 10No. of working wells No. of backup wells at water intake for Category:

I II IIIFrom 1 to 4 1 1 1From 5 to 12 2 1 —13 or more 20% 10% —Notes:1. Depending on the hydrogeologic conditions, and with proper substantiation, the number of backup wellsmay be increased.2. For water intakes of all categories, provision shall be made for the presence of the following numbers ofbackup pumps at the warehouse: one backup pump when there are up to 12 working wells, and 10% of the numberof working wells if the number is larger.3. The categories of water intakes in terms of assuredness of water supply shall be taken from Para-graph 4.4.

5.14. Water intake wells that exist in a sector and further use of which is impossible shall beabandoned by plugging.

5.15. Well filters shall be installed in unconsolidated, unstable rocks and mixed rock–soil strata.5.16. The design and size of the filter shall be determined in relation to hydrogeologic conditions,

flow, and operating conditions according to recommended Appendix 2.5.17. The final casing diameter when percussive drilling is used shall be at least 50 mm greater

than the outside diameter of the filter, or at least 100 mm greater when the filter is sprinkled over withgravel.

In rotary drilling without wall reinforcement by casing, the final well diameter shall be at least 100mm greater than the outside diameter of the filter.

5.18. The length of the working part of the filter in artesian aquifers up to 10 m thick shall beequal to the thickness of the aquifer; in free aquifers, it shall be equal to the thickness of the aquifer, lessthe operational decrease in the water level in the well (the filter generally must be flooded), with consid-eration for Paragraph 5.19.

In aquifers more than 10 m thick, the length of the working part of the filter shall be determinedwith consideration for the water permeability of the rocks, the flow of the wells, and the filter design.

5.19. The working part of the filter shall be mounted at least 0.5–1 m from the top and bottom ofthe aquifer.

5.20. When several aquifers are used, filter working parts shall be installed in each aquifer andshall be interconnected by point-to-point pipes (which cross over layers with poor water permeability).

5.21. The top part of the pipe above the filter shall be at least 3 m above the casing shoe if thedepth of the well is up to 50 m, and at least 5 m above it if the well depth is greater than 50 m; here, a sealshall be installed between the casing and the pipe above the filter.

5.22. The length of the settling tank shall be no more than 2 m.5.23. No-filter well designs for groundwater intake from unconsolidated sand deposits shall be

used provided that stable rocks overlie them.

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5.24. After the completion of well drilling and the equipment of wells with filters, provision shallbe made for pumping and, in the case of rotary drilling using a drilling mud, for mud removal until thewater is completely clear.

5.25. To determine whether the actual flow from water-intake wells corresponds to the valuespecified in the plan, provision shall be made for sampling by pumping out fluid according to theinstructions given in recommended Appendix 3.Dug Wells

5.26. Dug wells generally shall be used in the first free aquifers from the surface that arecomposed of unconsolidated rocks and that lie at depths down to 30 m.

5.27. If the thickness of the aquifer is up to 3 m, provision shall be made for completed dug wellspenetrating the entire thickness of the aquifer; if the thickness is greater, completed and uncompleted wellspenetrating part of the aquifer may be used.

5.28. If the water-intake section is located in sandy soil at the bottom of the well, an inverse sand–gravel filter or a porous-concrete filter shall be provided, and porous-concrete or gravel filters shall be usedin the walls of the water-intake section of the wells.

5.29. An inverse filter shall be made of several layers of sand and gravel, each with a thickness of0.1–0.15 m and with a total thickness of 0.4–0.6 m, with emplacement of fine fractions in the bottom partof the filter, and of coarse filters in the top part.

5.30. The mechanical composition of individual filter layers and the ratios of the average grainsize of adjacent filter layers shall conform to the instructions presented in recommended Appendix 2.

5.31. The top section of dug wells shall be at least 0.8 m above ground level. A pavement 1–2 mwide with a slope of 0.1 away from the well shall be provided around the well; a cutoff wall of clay or clayloam 1.5–2 m deep and 0.5 m wide also shall be provided around wells that supply water for domestic anddrinking needs.

5.32. In wells provision shall be made for a vent pipe that goes at least 2 m above ground level.The opening of the vent pipe shall be protected by a cap with a screen.Horizontal Water Intakes

5.33. Horizontal water intakes generally shall be provided at a depth of up to 8 m in free aquifers,mainly nearly surface watercourses. They may be designed in the form of a stone-and-rubble drain, a pipedrain, or a catch gallery or drift.

5.34. It is recommend that water intakes in the form of a stone-and-rubble drain be provided fortemporary water-supply systems.

Pipe drains shall be designed at depths of up to 5–8 m for water intakes of categories II–III.Catch galleries generally shall be provided for water intakes of categories I and II.Water intakes in the form of a drift shall be used in appropriate orographic conditions.5.35. To eliminate the entrainment of rock particles from the aquifer, the design of the water-

receiving part of horizontal water intakes shall provide for an inverse filter of two or three layers.5.36. The mechanical composition of individual layers of a inverse filter shall be determined by

analysis.The thickness of individual filter layers shall be at least 15 cm.5.37. For a water intake in the form of a stone-and-rubble drain, water intake shall proceed

through a rubble prism measuring 30 × 30 or 50 × 50 cm, laid on the bottom of the trench, with installationof a inverse filter.

A stone-and-rubble drain shall have a slope of 0.01–0.05 toward the sumpwell.5.38. The water-intake part of water intakes made of pipe drains shall be made of ceramic,

asbestos-cement, reinforced-concrete, and plastic pipes with round or slotted openings on the sides and inthe top part of the pipe; the bottom part of the pipe (no more than the one-third in height) shall have noholes. The minimum pipe diameter shall be 150 mm.

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Note: The use of perforated metal pipes is allowed if proper substantiation is given.5.39. The diameters of pipes used in horizontal water intakes shall be determined for the period

when the water table is at a low point, and the design fill shall be 0.5 times the diameter of the pipe.5.40. The slopes of pipes toward the sumpwell shall be at least:

0.007 for a diameter of 150 mm;0.005 for a diameter of 200 mm;0.004 for a diameter of 250 mm;0.003 for a diameter of 300 mm;0.002 for a diameter of 400 mm; and0.001 for a diameter of 500 mm.

The water speed in pipes shall be at least 0.7 m/sec.5.41. Water-intake galleries shall be made of precast reinforced concrete with slotted openings or

ports with baffles.5.42. Under the reinforced-concrete sections of a gallery there shall be a base to prevent settling of

the sections relative to each other. An inverse filter shall be provided on the sides of the gallery within itswater-intake section.

5.43. Horizontal water intakes shall be protected against the entry of surface water.5.44. To allow observation of the operation of pipe-type and gallery water intakes, as well as

ventilation and repair of them, inspection manholes shall be provided; the distance between them shall be nomore than 50 m for pipe-type water intakes with a diameter of 150–500 mm, and no more than 75 m for adiameter of more than 500 mm; for gallery water intakes the spacing shall be 100–150 m.

Inspection manholes also shall be provided at points where the direction of the water-intake sectionchanges in the horizontal and vertical planes.

5.45. Inspection manholes shall have a diameter of 1 m; the top of the manholes shall rise at least0.2 m above ground level; a water-impervious pavement at least 1 m wide and a clay cutoff wall shall bemade around the manholes; the wells shall be equipped with ventilation pipes according to Paragraph 5.32.

5.46. Pumping stations of horizontal water intakes generally shall be combined with the sumpwell.5.47. Combined horizontal water intakes shall be used in two-aquifer systems with a top free

aquifer and a bottom artesian aquifer. The water intake shall be in the form of a horizontal pipe drain thattaps the top free aquifer, to which branch pipes from the filter columns of vertical booster wells going intothe bottom aquifer are connected from below or from the side.

Horizontal Filter Wells

5.48. Horizontal filter wells shall be provided in aquifers whose roof is at a depth of no more than 15–20m from the ground surface, where the thickness of the aquifer does not exceed 20 m.Note: It is recommended that horizontal filter wells in pebbly ground with a coarseness D60 ≥ 70 mm not be usedwhen the aquiferous rocks contain inclusions of boulders in a quantity of more than 10% or in silty fine-grainedrocks.

5.49. Multitiered horizontal water intakes with branches at different elevations shall be used innonuniform or thick uniform aquifers.

5.50. When the delivery of a water intake is up to 150–200 L/sec and under favorablehydrogeologic and hydrochemical conditions, the sumpwell shall be of the single-section type; when thedelivery of the water intake exceeds 200 L/sec, the sumpwell shall be divided into two sections.

5.51. Branches 60 m or more in length shall be of a telescopic design, with a tapering of the pipediameter.

5.52. If the branches have a length of less than 30 m in uniform aquifers, the angle betweenbranches shall be at least 30°.

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5.53. Water-intake branches shall be made of perforated steel or slotted pipes with a porosity ofno more than 20%; the installation of gate valves shall be provided for on water-intake branches insumpwells.

Capping of Springs

5.54. Capping (tapping) devices (catch chambers or shallow drop shafts) shall be used to capture groundwater from springs.

5.55. Water intake from an upwelling spring shall be made through the bottom of the cappingchamber, and from a downflowing spring it shall be handled through openings in the chamber wall.

5.56. When springs from fractured rocks are tapped, water intake in the capping chamber may beperformed without filters, but if the springs come from unconsolidated rocks it shall be performed throughinverse filters.

5.57. Capping chambers shall be protected against surface contamination, freezing, and floodingby surface water.

5.58. An overflow pipe designed to handle the maximum flow of the spring with a flap-type valveinstalled on the end, a vent pipe per Paragraph 5.32, and an outlet pipe at least 100 mm in diameter shall beprovided in the capping chamber.

5.59. To free the spring water from suspension, the capping chamber shall be divided into twocompartments by an overflow wall: one compartment is for settling of the water, followed by removal ofthe sediment, and the second is for water intake by a pump.

5.60. If there are several water outlets near a downflowing spring, the capping chamber shall beprovided with lean-to structures.

Artificial Replenishment of Groundwater Reserves

5.61. Artificial replenishment of ground water shall be used to:Increase output and ensure stable operation of existing and planned groundwater intakes;Improve the quality of ground water that is infiltrating and that is being withdrawn;Create seasonal groundwater reserves; andProtect the environment (prevent unacceptable lowering of the water table, leading to the death ofvegetation).

5.62. Surface and ground waters shall be used to replenish groundwater reserves in aquifers thatare being exploited.

5.63. Replenishment of groundwater reserves shall be provided through infiltration (seepage)structures of the open and closed types.

5.64. The following shall be used as open-type infiltration structures: basins, and natural andartificial depressions in the terrain (gullies, ravines, oxbows, open-cut pits).

5.65. Open infiltration structures shall be used to replenish groundwater reserves of the firstaquifer from the surface in the absence of overlying low-permeability deposits, or if they have a smallthickness (up to 3 m).

5.66. The design of infiltration basins shall provide for:Cutting of the bottom into rocks with good filtration properties to a depth of at least 0.5 m;Reinforcement of the bottom at the point of water outlet, and prevention of slope erosion;A unit to regulate and measure the flow of water going to the infiltration structures; andAccess roads and access tracks for machinery.

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5.67. The width of infiltration basins shall not exceed 30 m, the length of the basins shall notexceed 500 m, the water layer shall be 0.7–2.5 m, and there shall be at least two basins.

5.68. Water supply to basins shall be provided through sprinklers or a cascade with free outflow.5.69. When basins are set up in gravel–pebble beds with coarse fill, the bottom shall be charged

with coarse-grained sand in a layer 0.5–0.7 m thick.5.70. When natural depressions in the terrain are used, provision shall be made for preparation of

the filtering surface.5.71. Wells (absorption and drainage–absorption wells) and open pits shall be used as closed-type

infiltration structures.5.72. The design of absorption and drainage–absorption wells shall provide for units to measure

and regulate the flows of water being supplied and to measure the dynamic water levels in structures and inthe aquifer.

5.73. The design of infiltration structures shall afford the possibility of restoring their output inopen infiltration structures by mechanical or hydraulic removal of the plugged layer from the filteringsurface, and in closed structures by methods used to reactivate water-intake wells.Note: The emptying and refilling of open infiltration structures during periods with subzero-centigradetemperatures are not allowed.

5.74. The selection of a siting plan for infiltration structures and the determination of the numberof them and their capacity shall be based on comprehensive hydrogeologic and feasibility calculations withconsideration for the function of artificial replenishment of groundwater reserves, siting plans of water-intake structures, the quality of the water being supplied, and the specifics of the operation of infiltrationand water-intake structures.

5.75. The distances between infiltration and water-intake structures shall be based on a forecast ofthe quality of the water to be withdrawn, with consideration for additional treatment of the water suppliedfor infiltration and its mixing with ground water.

5.76. The quality of water used for artificial replenishment shall meet the requirements of GOST2761-84.

5.77. The quality of water supplied to the infiltration structures of domestic-/drinking-watersupply systems shall meet the requirements of GOST 2874-82, with consideration for additional treatmentduring infiltration into the aquifer and for mixing with ground water.

SURFACE WATER-INTAKE STRUCTURES

5.78. Water-intake structures (water intakes, or water inlets) shall:Provide intake of the design water flow from a water source, and supply of the flow to the consumer;Protect the water-supply system from biological fouling and from the entry of sediments, small trash,plankton, slush ice, and so forth; andIn water bodies of importance to the fishing industry, meet the requirements of agencies in charge ofprotection of fish resources.

5.79. In terms of the assuredness of water supply, water intakes shall be subdivided into threecategories per Paragraph 4.4.

5.80. The design of a water intake shall be adopted in relation to the required category, thehydrologic characteristics of the source with consideration for the maximum and minimum water levelsspecified in Table 11, and the requirements of water-management and -conservation agencies, the sanitationand epidemiology service, agencies that protect fish resources, and water-transportation agencies.

5.81. The class of primary water-intake structures shall be set according to their category.

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Table 11Category of water intake Assuredness of design water levels in surface

sources (%)Maximum Minimum

I 1 97II 3 95III 5 90

The class of secondary water-intake structures shall be smaller by one.Notes:

1. Primary structures shall include structures upon damage to which the water intake will not provide thedesign water flow to consumers, and secondary structures shall include structures damage to which does not leadto a decrease in water supply to consumers.

2. The class of water-life and water-reservoir dams that are part of a water-intake hydraulic complexshall be adopted according to the instructions in SNiP II-50-74, but shall be at least:— Class II for Category I water intakes;— Class III for Category II water intakes; and— Class IV for Category III water intakes.

5.82. The selection of a water-intake plan and location shall be substantiated by forecasts of:• The water quality at the source;• The reshaping of the channel or shoreline;• A change in the permafrost boundary; and• The hydrothermal regime.5.83. It is not allowed to place water intakes in navigation zones of ships or rafts, in an area where

bottom sediment is laid down or moves copiously, at fish wintering and spawning grounds, on a sectionwhere collapse of the shore or bank is possible, at places where driftwood piles up or algae cluster, or atsites of ice jams and ice gorges.

5.84. It is not recommended to place the water-intakes proper of water-intake structures onsections of the tailrace of a hydroelectric power plant adjacent to a hydraulic complex, in the headwater ofwater reservoirs, and on sections downstream from the mouths of tributaries of watercourses and at themouths of the backwaters of watercourses.

5.85. The location of water intakes of water-intake systems for domestic-/drinking-water supplyshall be upstream on the watercourse from waste-water discharges, localities, ship berths, lumberyards,trading and transportation bases and warehouses in an area that allows the organization of sanitaryprotection zones.

5.86. In seas, large lakes, and reservoirs, the water intakes of water-supply systems shall beplaced (with consideration for the expected reworking of the adjacent shoreline and nearshore slope) asfollows:

• Outside the breaker zones when the water is at its lowest levels;• At points sheltered from the waves; and• Outside concentrated currents coming out of breaker zones.On water intakes with gravity-flow and siphon water lines, it is advisable to place a screened intake

well, the pumping station, and other structures outside the expected area of shoreline reworking, withoutbuilding aprons.

5.87. The conditions of water intake from surface sources shall be divided in relation to thestability of the shores (banks) and the channel of the source, channel and slush-ice conditions, and degree ofcontamination, according to the parameters given in Table 12.

5.88. Water-intake devices shall be adopted per Table 13 in relation to the required category andthe complexity of the natural conditions of water intake (Table 12).

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5.89. The category of a water intake with flooded intake areas may be raised by one in thefollowing cases:

• If the water intakes are located in self-flushing water-intake basins that can flood;• If water is supplied to the water-intake openings in a quantity of at least 20% of the flow being

taken in, and if special sediment-screening units are used; or• If there is a reliable system of back-flushing of trash-catching gratings, fish-protection

structures of water intakes, and gravity-flow water lines.5.90. The selection of the design and layout of a water-intake structure in difficult and very

difficult local conditions shall be based on laboratory studies.5.91. Water-intake structures shall be designed with consideration for the long-term development

of water consumption.5.92. When water is drawn from reservoirs, consideration shall be given as to whether it is

advisable to use the towers of a bottom water outlet or sluiceway headworks as the water intake.If a water-intake structure is combined with a water-life dam, provision shall be made for the

possibility of repairing the dam without cutting off the water supply.

Table 12Conditions of water intake

from surface sourcesWater-intake

conditionsTurbidity, stability of shores

(banks) and bottomSlush and ice Other factors

Mild Turbidity ≤ 500 mg/L, stablechannel of water body andwatercourse.

No ice formation within thewater. Freeze-up of moderatethickness (≤0.8 m), stable.

No Dreissena, rock barnacles,marine mussels, and so forth, noalgae, a small amount ofcontaminants and trash.

Average Turbidity ≤ 1500 mg/L (averagefor high-water period). Channel(shore) and banks are stable,with seasonal deformations of±0.3 m. Movement ofsediments along shore (bank)does not affect the stability ofany underwater slope ofconstant curvature.

Ice formation within the water,terminating with the completefreeze-up, usually without slushfilling the channel and formingslush jams. Freeze-up is stable,with a thickness of < 1.2 m, andair holes form.

Presence of trash, algae,Dreissena, rock barnacles, marinemussels, and contaminants inamounts that interfere with theoperation of the water intake.Loose floating and rafting.Navigation.

Severe Turbidity ≤ 5000 mg/L.Channel is mobile, with re-forming of the shores andbottom, causing a change of upto 1–2 m in bottom depths.Reworking of the shore, withmovement of sediments alongthe shore down a slope ofvariable curvature.

Repeatedly forming ice coverwith moving sludge and slushfilling the channel, with freeze-up of up to 60–70% of the crosssection of the watercourse. Insome years ice jams form in theprefreeze-up period, and icegorges form in spring. Sectionsof the tailrace of a hydroelectricpower plant are within the zoneof unstable ice cover. Slush iceis driven to shore, with theformation of heaps on the shoresand of hummocks, and withslush filling the coastal(nearshore) zone.

The same, but in amounts thatmake it hard for water-intake andwater-piping structures to operate.

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Conditions of water intakefrom surface sources

Water-intakeconditions

Turbidity, stability of shores(banks) and bottom

Slush and ice Other factors

Very severe Turbidity > 5000 mg/L, channelis unstable, changing formsystematically and randomly.Intensive and significantreworking of the shore (bank).Presence or likelihood of slides.

Formation of ice cover only atice gorges, causing backwater;passage of slush under the icecover during most of the winter.Ice crusts and freezing-over ofthe channel are possible. Iceflow with jams and with largeice heaps on the shores. Severeslush-ice conditions when tidesare present.

Note: The general characteristics of water-intake conditions are determined from the most severe type ofproblems.

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Table 13Category of water-intake structureNatural conditions of water intake

Water-intake devices Mild Average SevereWater-intake plans

a b c a b c a b cShoreline water intakes that donot flood, with intake openingsthat always are accessible formaintenance, with the requisiteenclosures and auxiliary struc-tures and devices

I — — I — — II I I

Flooded water intakes of alltypes, distant from the shore,practically inaccessible at sometimes of the year

I — — II I — III II I

Nonfixed water-intake units:FloatingFunicular

IIIII

III

——

III—

III—

II—

——

——

——

Notes:1. Table 13 was compiled for water intakes set up on three plans: plan “a” — in a single section; plan “b”— the same, but with several water intakes equipped with devices to combat slush, sediments, and otherhindrances to water intake; and plan “c” — in two sections separated by a distance that prevent simultaneousinterruption of water intake.2. Sectionalization of the water-intake portion shall be provided in category I and II water-intake structures.

5.93. The dimensions of the main elements of a water-intake structure (intake openings, screens,fish-protection devices, pipes, channels), the design minimum water level in a screened onshore intake well,and the elevations of the pumps shall be determined by hydraulic calculations for the minimum water levelsat the source for normal operating and emergency conditions.Note: Under emergency conditions (with one gravity-flow or siphon water line or water-intake section shut downfor repair or inspection), water withdrawal may be reduced by 30% for category II and III water-intake structures.

5.94. The dimensions of water-intake openings shall be determined from the average inflow speedof water entering the openings (in the clear) of trash-catching gratings and screens or filter pores withconsideration for fish-protection requirements.

The permissible rates of water inflow into water-intake openings without regard for fish-protectionrequirements shall be adopted for average and severe conditions of water intake, respectively:0.2–0.6 m/sec for inflow into onshore water intakes that do not flood; and0.1–0.3 m/sec for inflow into flooded water intakes.

With consideration for fish-protection requirements:In watercourses with flow speeds greater than 0.4 m/sec, the permissible inflow speed is 0.25 m/sec; andIn watercourses with flow speeds no higher than 0.4 m/sec and in water bodies the flow speed shall notexceed 0.1 m/sec.

For very severe slush-ice conditions the speed of water inflow into water-receiving ports shall belowered to 0.06 m/sec.

5.95. A determination of the (gross) area Ωgross (m2) of the water-intake opening of one sectionshall be made for simultaneous operation of all sections of the water intake (except backup sections) fromthe equation:

Ωgross = 1.25qdKc/vin, (5)where vin is the speed (m/sec) of inflow into water-intake openings, referred to their clear cross section;1.25 is a factor that takes into account clogging of the openings; qd is the design flow of one section(m3/sec); and Kc is a factor that takes into account the constriction of the openings by the bars of the

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gratings or screens, assumed to be: Kc = (ab + cb)/ab for gratings, and Kc = [(ab + cb)/ab]2 for screens, where

cb is the distance (cm) between bars in the clear, and ab is the thickness (cm) of the bars.In filter-type water intakes, the area of the intake filter shall be determined from Equation (5) for

the value Kc = 1/Pf, where Pf is the porosity of the filter, assumed to be 0.3–0.5 m for gravel-and-rubblefilters, and 0.25–0.35 m for porous plastic filters.

5.96. The bottom of water-intake openings shall be at least 0.5 m above the bottom of the waterbody or watercourse, and the top of the intake openings or flooded structures shall be at least 0.2 m fromthe bottom edge of the ice.

5.97. To combat icing and blocking of water intakes by slush under severe slush-ice conditions,electric heating of the grates shall be provided, and there shall be a supply of warm water or compressed airto the intake openings, or pulsed washing shall be combined with backwashing. The bars of trash gratesshall be made of hydrophobic materials or shall be covered with them.Notes: Appropriate fittings shall be provided to remove slush ice from onshore water-intake wells and screenedchambers.

5.98. If necessary, steps shall be taken to prevent the fouling of elements of a water-intakestructure by Dreissena, rock barnacles, marine mussels, and so forth by treating the water with chlorine ora copper sulfate solution.

The doses, frequency, and duration of water treatment with reagents shall be determined on thebasis of data from engineering studies.

In the absence of these data, the chlorine dose shall be 2 mg/L above the chlorine absorptivity ofthe water, but at least 5 mg/L.

It is recommended that the frequency and duration of chlorination be as follow for the followingchlorine absorptivities of water:Up to 3 mg/L in spring and fall for 7–10 days; andMore than 3 mg/L from May to October on those days when the average daily air temperature exceeds+10°C.

The dose of copper sulfate (referred to copper) shall be 1–1.5 mg/L.The frequency and duration of copper sulfate treatment shall be every other day for 1 hr.

Notes:1. It is permitted to use varnish, paint, and plastic coatings on elements of water-intake structures.2. In a period of backflushing of water intakes and gravity-flow water lines, it is not permitted to supply

reagents to water intakes.5.99. The approximate speeds of the water in gravity-flow and siphon water lines under normal

operating conditions of water-intake structures may be taken from Table 14.

Table 14Diameters ofwater lines (mm)

Water speeds (m/sec) in waterintakes of categories:I II & III

300–500 0.7–1 1–1.5500–800 1–1.4 1.5–1.9>800 1.5 2

Note: If the possibility exists of fouling of water lines by Dreissena, rock barnacles, marine mussels, and so forth,the losses in the water line shall be calculated for a roughness coefficient of 0.02.

5.100. Siphon water lines may be used in category II and III water intakes.The use of siphon water lines in Category I water intakes must be substantiated.5.101. Siphon and gravity-flow water lines generally shall be made of steel pipes. It is permitted

to use plastic and reinforced-concrete pipes.

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5.102. For gravity-flow water lines on a section bordering on the underground part of water-intakewells and pumping stations using the overpour (drop) method, the method of no-trench laying isrecommended.

5.103. Steel gravity-flow and siphon water lines shall be checked for flotation, and shall beprovided with anticorrosion backing insulation and, if necessary, with cathodic protection or a protector. Ifareas with permafrost are crossed by gravity-flow or siphon water lines, measures shall be provided toprevent water from freezing inside the water line.

5.104. Gravity-flow and siphon water lines within the channel of a watercourse shall be protectedon the outside against abrasion by bottom sediments, and against damage by anchors by burying the waterlines beneath the bottom with consideration for local conditions, but at least 0.5 m down, or by covering itwith dirt reinforced against erosion.

5.105. The type of screens for pretreatment of water shall be selected with consideration for thespecifics of the water body and the capacity of the water intake.

Rotating screens shall be used under average, severe, and very severe conditions of sourcecontamination according to Table 12, and also whenever the capacity of the water intake is more than 1m3/sec.

5.106. When fish-protection devices are present at the water-withdrawal site, the working area offlat or rotating screens shall be determined at minimum water level in a screened well and at a speedassumed not to exceed 1 m/sec in the screen openings.

5.107. When filter elements are used as fish-protection measures or filter-type water intakes areset up, in certain cases consideration shall be given to the possibility of making the decision not to installwater-treatment screens.

5.108. Pumping stations of water-intake structures shall be designed according to the instructionsin Section 7.

Here, it is recommended that pumps with a vertical shaft be used in the pumping stations of waterintakes.

5.109. In the design of water-intake structures, devices shall be provided to remove sediment fromthe water-intake chambers (wells).

Water from pressurized water lines shall be used to wash screens. If the head is insufficient towash them, booster pumps shall be installed.

6. WATER TREATMENT

General Instructions

6.1. The requirements of this section do not extend to the water treatment facilities of thermalpower plants.

The design of water treatment facilities for boiler shops with boilers operating at pressures of up to4 MPa (40 kgf/cm2), as well as heat and hot water supply systems, shall be conducted in accordance withthe requirements of SNiP II-35-76 and SniP 2.04.07-86.

6.2. The method of treating water, composition and design parameters of water treatment facilitiesand calculated reagent doses shall be established depending on the quality of water at the water source, thedesignation of the water line, throughput capacity of the facility and local conditions based on the data ofprocess studies and experience gained in the operation of other facilities under similar conditions.

6.3. Preparation of drinking water may be performed using only methods which have receivedhygienic approval.

6.4. Wash water from filters, water gained by dewatering and stowing water treatment plantsediment shall be reused. When justified, it is permissible to dump these types of water into streams or

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bodies of water, observing the requirements of the “Rules for Preservation of Surface Bodies of Waterfrom Pollution by Wastewater,” Ministry of Land Reclamation and Water Resources, USSR, Ministry ofHealth, USSR, and the Ministry of Fishing Industry, USSR, or into sewerage and treatment facilities.

6.5. Equipment, pipes and fittings of water treatment plants shall be designed considering therequirements of Section 12. Facilities at water treatment plants shall be equipped with instruments anddevices for determination of the basic parameters of their operation in accordance with Section 13, as wellas devices for taking of samples before and after each facility.

6.6. The total amount of water entering a plant shall be determined considering the amount ofwater consumed internally by the plant.

The approximate average daily (throughout the year) consumption of incoming water for internalplant use for clarification, deferrization, etc. shall be taken as: with reuse of wash water 3-4% of thequantity of water supplied to consumers, without reuse of wash water—10-14%, for softening plants—20-30%. The consumption of water for internal plant requirements shall be refined by calculation.

6.7. Water treatment plants shall be designed for smooth operation during days of maximum waterconsumption, allowing the possibility of disconnecting individual facilities for inspection, cleaning,maintenance, repair and overhaul. For plants with throughput capacity up to 5000 m3/day it is permissibleto provide for operations during a portion of the day.

6.8. Connection lines in water treatment plants shall be designed to allow the passage of 20-30%more water than the standard design flow.

CLARIFICATION AND DISOLORATION OF WATER

General

6.9. The water found in water supply sources is classified as follows:a) depending on the maximum design turbidity (approximate quantity of suspended matter) as:

low turbidity—up to 50 mg/L;moderate turbidity—over 50 up to 250 mg/L;turbid—over 250 up to 1500 mg/L;highly turbid—over 1500 mg/L;

b) depending on the maximum design content of humous substances causing coloration of the water, as:slightly colored—up to 35º;moderately colored—over 35 up to 120º;highly colored—over 120º.

The maximum design values of turbidity and coloration used in the design of water treatment plantfacilities shall be determined based on analysis of water over a period of at least the last three years prior toselection of the water source.

6.10. When selecting facilities for clarification and decoloration of water, it is recommended to usethe instructions of Paragraphs 6.2 and 6.3, for preliminary selection—the data of Table 15.

Drum-Type Screen Filters

6.11. Drum-type screen filters shall be used to remove coarse floating and suspended matter (drumscreens) and for removal of these impurities plus plankton (microfilters).

Drum screen filters shall be located on the site of water treatment plants, or when the need isdemonstrated they may be located at water intake facilities.Drum screen filters shall be installed before reagents are fed into the water.

6.12. The number of reserve drum screen filters shall be:1—with number of operating units 1-5;

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2—with number of operating units 6-10;3—with number of operating units 11 or more.

Table 15Conditions of use Throughput

ofBasic Facilities Turbidity, mg/L Color index, degrees Plant,

m3/dayInputwater

Treatedwater

Inputwater

Treatedwater

Water treatment using coagulants and flocculants1. Rapid filters (single-stagefiltering):

a) pressure filtersb) open filters

up to 30up to 20

up to 1.5up to 1.5

up to 50up to 50

up to 20up to 20

up to 5000up to 50,000

2. Vertical settling tanks—rapidfilters

up to1500

up to 1.5 up to 120 up to 20 up to 5000

3. Horizontal settling tanks—rapid filters

up to1500

up to 1.5 up to 120 up to 20 over 30,000

4. Contact prefilters—rapidfilters (two-stage filtration)

up to 300 up to 1.5 up to 120 up to 20 any

5. Clarifiers with suspendedsediment—rapid filters

at least 50up to1500

up to 1.5 up to 120 up to 20 over 5000

6. Two-stage settling—rapidfilters

over 1500 up to 1.5 up to 120 up to 20 any

7. Contact settling tanks up to 120 up to 1.5 up to 120 up to 20 “8. Horizontal settling tanks andclarifiers with suspendedsediment for partial clarificationof water

up to1500

8-15 up to 120 up to 40 “

9. Large-grain filters for partialclarification of water

up to 80 up to 10 up to 120 up to 30 “

10. Radial settling tanks forpreliminary clarification of highlyturbid water

over 1500 up to 250 up to 120 up to 20 “

11. Tube settling and factory-made pressure filter (“jet” type)

up to1000

up to 1.5 up to 120 up to 20 up to 800

Treatment of water without coagulants and flocculants12. Large-grain filters for partialwater clarification

up to 150 30-50% ofinitial

up to 120 same asinitial

any

13. Radial settling tanks forpartial clarification of water

over 1500 30-50% ofinitial

up to 120 “ “

14. Slow filters with mechanicalor hydraulic sand regeneration

up to1500

1.5 up to 50 up to 20 “

Notes: 1. Turbidity given is total, including that formed by addition of reagents.2. At water intake facilities or water treatment plants, screens shall be installed with openings of 0.5-2mm. With average monthly content of plankton in water over 1000 cl/ml and “bloom” time over 1 month

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per year, in addition to screens at the water intake, microfilters shall be installed at the location of thewater intake or at the water treatment plant.3. When justified, facilities not given in Table 15 may be used for water treatment (floating water intake-clarifiers, hydrocyclones, flotation units, etc.).4. Clarifiers with suspended settlement shall be used with uniform flow of water to facilities or gradualchange in water flow rate within limits of not over ±15% per hour and water temperature fluctuations ofnot over ±1°C per hour.

6.13. Drum screen filters shall be installed in chambers. It is permissible to place two units in onechamber if the total number of operating units is over 5.

Chambers shall be equipped with drain pipes.Overflow pipes shall be provided in the feed channel for the chambers.6.14. Washing of drum screen filters shall be performed using the water passing through them.The consumption of water for internal needs shall be taken as: for drum screens—0.5% and for

microfilters—1.5% of the design throughput.Reagent Use

6.15. The calculated dose of reagents shall be established for various periods of the year dependingon the quality of the incoming water, and shall be adjusted during setup and operation of the facilities. Thepermissible residual concentration of reagents in the treated water shall be considered, as provided for inGOST 2874-82 and the processing requirements.

6.16. The dose of coagulant, Dc, mg/L, as Al2(SO4)3, FeCl3, Fe2(SO4)3 (anhydrous matter) may betaken for processing of: turbid water from Table 16, colored water by the equation

D Cc = 4 , (6)

where C is the color index of the treated water, degrees.Note: When the water contains suspended matter and is colored, the greater of the coagulant dosesdetermined from Table 16 and equation (6) shall be used.

Table 16Turbidity of water, mg/L Dose of anhydrous coagulant for treatment

of turbid water, mg/LUp to 100 25-35From 100 to 30-40“ 200 “ 35-45“ 400 “ 45-50“ 600 “ 50-60“ 800 “ 1000 60-70“ 1000 “ 1500 70-80

Notes: 1. The lower dose is for water containing coarse dispersed matter.2. When contact clarifiers or filters operating on the principle of coagulation in the filtration zone areused, the dose of coagulant shall be 10-15% less than that taken from Table 16 and equation (6).

6.17. The dose of flocculants (in addition to the dose of coagulants) shall be:a) polyacrylamide (PAA) as the anhydrous product:

when introduced before settling tanks or clarifiers with suspended sediment—as in Table 17;

Table 17Turbidity, mg/L Color index, degrees Anhydrous PAA, mg/LUp to 10 over 50 1-1.5From 10 to 30-100 0.3-0.6“ 100 ” 20-60 0.2-0.5

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“ 500 ” — 0.2-1when added before filters in two-stage treatment—0.05-0.1 mg/L;when added before contact clarifiers or filters with one-stage treatment, and also before prefilters—

0.2-0.6 mg/L;b) active silicic acid (as SiO2):

when added before settling tanks or clarifiers with suspended sediment or water with temperature over 5-7°C—2-3 mg/L, with temperature less than 5-7°C—3-5 mg/L;

when added before filters in two-stage treatment—0.2-0.5 mg/L;when added before contact clarifiers or filters with one-stage treatment, and also before prefilters—

1-3 mg/L.Flocculants shall be introduced to water after the coagulant. When treating highly turbid water,

flocculants may be added before coagulants. The possibility shall be provided of introducing flocculantsand coagulants at a time interval of up to 2-3 minutes, depending on the quality of the water being treated.

6.18. The dose of chlorine-containing reagents (as active chlorine) in preliminary chlorination andto improve the process of coagulation and decoloration of water, and also to improve the sanitary conditionof facilities, shall be 3-10 mg/L.

It is recommended that reagents be added 1-3 minutes before coagulants are added.6.19. The doses of alkalizing reagents, Da, mg/L, required to improve the process of floc formation,

shall be determined by the equationDa = Ka (Dc/ec – A0) + 1, (7)

where Dc is the maximum dose of anhydrous coagulant during the period of alkalizing, mg/L;ec is the equivalent mass of (anhydrous) coagulant, mg/mg-eq, taken as: for Al2(SO4)3—57, FeCl3—54,Fe2(SO4)3—67;Ka is a coefficient which is: for lime (as CaO)—28, for soda (as Na2CO3)—53;A0 is the minimum alkalinity of the water, mg-eq/L.

Reagents shall be introduced simultaneously with the coagulants.6.20. Preparation and measurement of reagents shall be in the form of solutions or suspensions.

The number of dosing units shall be taken as a function of the number of points of introduction and thethroughput capacity of a dosing unit, but shall not be less than two (one reserve).

Granulated and powdered reagents shall generally be used in dry form.6.21. The concentration of the solution of coagulant in dissolving tanks, as the dry, anhydrous

product, shall be as follows: up to 17% for unpurified, up to 20% for purified lump coagulants, up to 24%for purified granulated coagulants; in service tanks—up to 12%.

6.22. The length of the full cycle of preparation of a coagulant solution (charging, dissolution,settling, transfer, bottom cleaning when required) with water temperature up to 10°C shall be taken as 10-12 hours.

In order to speed up the coagulant preparation cycle to 6-8 hours it is recommended to use water ata temperature of up to 40°C.

The number of dissolving tanks shall be determined considering the quantity delivered at once,methods of delivery and unloading of the coagulant, its type, as well as the time required to dissolve it, andshall be no less than three.

The number of service tanks shall be no less than two.6.23. In order to dissolve the coagulant and mix it in the tanks, compressed air shall be fed in at a

rate of:8-10 L/(s⋅m2)—for dissolution;3-5 L/(s⋅m2)—for mixing during dilution to the required concentraiton in the service tanks.

Air shall be distributed by the use of tubing with holes.

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It is permitted to use mechanical agitators or circulation pumps for dissolution of coagulant andmixing of its solutions.

6.24. Dissolving tanks shall be designed with walls in the bottom portion inclined at an angle of45° to the horizontal for unpurified coagulant and 15° for purified coagulant. Pipes with a diameter of noless than 150 mm shall be used to empty tanks and drain sediment.

When lump coagulant is used, tanks shall be provided with removable grids with spacings of 10-15mm.

When granulated and powdered coagulant is used, a screen of acid-resistant material with 2 mmapertures shall be placed on the grating.Note: It is permissible to reduce the tank wall slope for unpurified coagulant to 25° if the portion of thetank beneath the grating is equipped with a system for washing down the sediment and simultaneouslyfeeding in compressed air.

6.25. The bottoms of service tanks shall have a slope of no less than 0.01 toward the drain pipe,which shall have a diameter of no less than 100 mm.

6.26. Coagulant solution from dissolving and service tanks shall be taken from the upper level.6.27. The inner surface of tanks shall be protected by acid-resistant materials.6.28. When using dry ferric chloride as the coagulant, a grate shall be provided in the upper

portion of the dissolving tank. Tanks shall be located in an isolated room (box) with exhaust ventilation.6.29. Acid-resistant materials and equipment shall be used for transportation of coagulant solution.The design of reagent lines shall provide for their rapid cleaning and washing.6.30. Polyacrylamide shall be used as a solution with a polymer concentration of 0.1-1%.Preparation of a solution from technical polyacrylamide shall be performed in tanks with

mechanical blade agitators. The time of preparation of a solution of PAA gel shall be 25-40 minutes, of dryPAA 2 hours. To speed up preparation of PAA solutions, hot water shall be used with a temperature of notover 50°C.

6.31. The number of agitators and the volume of service tanks for PAA solutions shall bedetermined so that the storage time of 0.7-1% solutions is not over 15 days, of 0.4-0.6 solutions—7 daysand 0.1-0.3% solutions—2 days.

6.32. Solutions of active silica (AS) shall be prepared by treating liquid glass with a solution ofaluminum sulfate or chlorine.

Activation by aluminum sulfate or chlorine shall be performed on continuous or batch-typeinstallations.

6.33. Alkalizing and stabilization of water shall be performed using lime. When justified, soda maybe used.

6.34. The selection of a lime processing system for a water treatment plant shall be performedconsidering the quality and type of plant product, the demand for lime, its point of insertion, etc. If lumpunslaked lime is used, it shall be wet stored as a paste.

With a lime use of up to 50 kg/day as CaO it is permitted to employ a system using a lime solutionproduced in double saturators.

6.35. The number of tanks of lime milk or solution shall be no less than two. The concentration oflime milk in the service tanks shall be not over 5% as CaO.

6.36. To cleanse lime milk of insoluble impurities during stabilization treatment of water, verticalsettling tanks or hydrocyclones shall be used.

The rate of the ascending flow in vertical settling tanks shall be 2 mm/s.Lime milk shall be fed twice through hydrocyclones when they are used to treat it.6.37. Hydraulic mixing (with pumps) or mechanical agitators shall be used for continuous mixing

of lime milk.

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With hydraulic mixing the ascending movement of the milk in the tank shall be no less than 5mm/s. Tanks shall have conical bottoms with slope 45° and drainage pipes no less than 100 mm indiameter.Note: Lime milk may be mixed using compressed air fed in at a rate of 8-10 L/(s⋅m2).

6.38. The diameters of lime milk feed pipes shall be as follows: pressurized pipes feeding thetreated product no less than 25 mm, untreated product—no less than 50 mm, gravity flow pipes—no lessthan 50 mm. The speed of movement of lime milk in the pipes shall be no less than 0.8 m/s. Bends on limemilk pipes shall have a radius of no less than 5d, where d is the diameter of the pipe. Pressure pipes aredesigned with a slope toward the pump of no less than 0.02, gravity-flow pipes shall have a slope towardthe discharge of no less than 0.03.

The possibility shall be provided of washing and cleaning pipes.6.39. The concentration of soda solution shall be 5-8%. Dosing of the solution shall be in

accordance with Paragraph 6.20.

MIXING DEVICES

6.40. Mixing devices shall include devices for input of reagents assuring rapid, uniformdistribution of the reagents in a water feed pipe or channel of the water treatment facilities, and mixerssupporting subsequent intensive mixing of the reagents with the water being treated.

6.41. Mixing devices shall provide gradual input of reagents at the necessary time intervals inaccordance with Paragraphs 6.17-6.19 and recommended Appendix 4 considering the time spent by thewater in the pipes or channels between reagent input devices.

6.42. Reagent input devices shall be made as perforated pipes in distributors or inserts into pipescreating local flow resistance. Reagent distributors shall be accessible for cleanout and washing withoutinterrupting the water treatment process. The loss of pressure in a pipe resulting from installation of a pipedistributor shall be taken as 0.1-0.2 m, upon installation of an insert—0.2-0.3 m.

6.43. Mixing of reagents with water shall be performed in hydraulic-type mixers (eddy or barriertypes). When justified, mechanical-type mixers (agitators) may be used.

6.44. The number of mixers (sections) shall be no less than two with the possibility ofdisconnecting them during periods of intense floc formation.Reserve mixers (sections) shall not be used, but it is necessary to provide a bypass pipe around mixers withreserve devices in the pipe for introduction of reagents in accordance with Paragraph 6.42.

6.45. Eddy mixers shall be used when water arrives at the treatment plant with coarsely dispersedsuspended matter and when reagents are used in the form of suspensions or partially clarified solutions.

Eddy mixers shall be used in the form of a conical or pyramidal vertical diffuser with an anglebetween slanting walls of 30-45°, height of upper portion with vertical walls 1 to 1.5 m, input-output flowrate in mixer from 1.2 to 1.5 m/s, rates of ascending movement of water under water intake device 30 to 40mm/s, rate of movement of water at end of water intake channel 0.6 m/s.

6.46. Barrier mixers shall be used in the form of channels with barriers causing horizontal orvertical movement of the water with 180° turns. The number of turns shall be 9-10.

6.47. The loss of head h in each turn of a barrier mixer shall be determined by the equation

h v g=ζ 2 2 , (8)

where ζ is the resistance factor, taken as 2.9;v is the velocity of the water in the mixer, assumed to drop from 0.7 to 0.5 m/s;g is the acceleration of free fall, which is 9.8 m/s2.

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6.48. Mixers shall be equipped with overflow and drainage pipes. The possibility shall be providedof decreasing the number of barriers in order to reduce the time spent by the water in the mixers duringperiods of intensive floc formation.

6.49. The velocity of water in pipes or channels from mixers to floc formation chambers andclarifiers with suspended sediment shall be taken as decreasing from 1 to 0.6 m/s. The time spent by waterin them shall be not over 1.5 minutes.

Air Separators

6.50. Air separators shall be provided when settling tanks are used which have flocculationchambers with a layer of suspended sediment, clarifiers with suspended sediment, contact clarifiers andcontact prefilters.

6.51. The area of air separators shall be determined by calculating the speed of descending motionof the water as not over 0.05 m/s and the time spent by the water in the device as no less than 1 minute.

Air separators may be made common for all facilities or for each facility individually.In those cases when the design of mixers can assure removal of air bubbles from the water and the

water does not take on additional air as it moves from mixers to facilities, air separators are not required.

Flocculation Chambers

6.52. Settling tanks shall contain hydraulic-type flocculation chambers. If justified, mechanical-type flocculation chambers may be used.

6.53. In horizontal settling tanks hydraulic flocculation chambers shall be of barrier or eddy typeor with a layer of suspended sediment.

6.54. Barrier-type flocculation chambers shall be used with horizontal or vertical motion of thewater. The speed of motion of the water in the corridors shall be taken as 0.2-0.3 m/s at the beginning ofthe chamber and 0.05-0.1 m/s at the end of the chamber by increasing the width of the corridor.

The time spent by water in the flocculation chamber shall be 20-30 minutes (the lower limit forturbid water, the upper water for colored water with low temperature in winter).

The width of the corridor shall be no less than 0.7 m. The number of turns of the flow in the barrierchamber shall be 8-10.

It is permissible to use two-stage chambers.The loss of head in the chamber shall be determined in accordance with Paragraph 6.47.6.55. Eddy-type flocculation chambers shall be designed with vertical or slanted walls (the angle

between the walls shall be taken as a function of chamber height within limits of 50-70°). The time spent bythe water in the chamber shall be equal to 6-12 minutes (the lower limit for turbid water, the upper limit forcolored water).

The speed of entry of the water in the chamber shall be taken as 0.7-1.2 m/s, the speed of theascending flow at the chamber exit as 4-5 mm/s.

Water shall be taken from the flocculation chamber of a settling tank with a rate of motion of thewater in intake troughs, pipes and apertures of not over 0.1 m/s for turbid water and 0.05 m/s for coloredwater.

The head loss in the chamber shall be determined in accordance with Paragraph 6.47.6.56. Flocculation chambers with a layer of suspended sediment with vertical barriers are used for

water of moderate turbidity and turbid waters. The ascending rate of flow shall be 0.65-1.6 mm/s forclarifying water of moderate turbidity and 0.8-2.2 mm/s for clarifying turbid water.

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When built-in flocculation chambers are used with a layer of suspended sediment, the designsettling rate of the suspended matter in the tank when treating turbid water shall be taken as 20%, whentreating water of moderate turbidity as 15% greater than that given in Table 18.

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Table 18Characteristics of water treated and method oftreatment

Settling rate of suspension u0

supported by settling tank, mm/sLow-turbidity colored water treated with coagulant 0.35-0.45Moderate-turbidity water treated with coagulant 0.45-0.5Turbid water treated with:

coagulant 0.5-0.6flocculant 0.2-0.3

Turbid water not treated with coagulant 0.08-0.15Notes: 1. Where flocculants are used the rate of precipitation of suspended matter shall be increased by15-20%.2. Lower limits of u0 are given for drinking domestic water supply lines.

6.57. The distribution of water over the area of a flocculation chamber with suspended sedimentshall be achieved by the use of pressurized perforated pipe with apertures directed downward at angle of45°. The distance between perforated pipes shall be 2 m, from the wall of the chamber—1 m.

The loss of head in the perforated distribution pipes shall be determined in accordance withParagraph 6.86.

The rate of motion of the water at the entry to a perforated pipe shall be 0.5-0.6 m/s, the area ofthe aperture 30-40% of the cross-sectional area of the distribution pipe, the diameter of the apertures noless than 25 mm.

6.58. Drainage of water from flocculation chambers into settling tanks shall be provided with arate of movement of the water of not over 0.1 m/s for turbid water and 0.05 m/s for colored water. At thepoint of entry of the water into the settling tank a suspended barrier shall be provided immersed to 1/4 ofthe height of the settling tank. The speed of motion of the water between the wall and the barrier shall benot over 0.03 m/s.

6.59. In vertical settling tanks a water-whirlpool hydraulic flocculation chamber shall be provided,located at the center of the settling tank. The water shall be fed into the flocculation chamber throughnozzles directed along a tangent. There shall be a grid at the bottom of the tank with apertures measuring0.5 × 0.5 m, height 0.8 m.

The loss of head in a nozzle shall be determined using equation (8) in Paragraph 6.47, assumingthe speed of the water at the nozzle exit to be 2-3 m/s and the resistance factor ζ = 1.18.

The nozzle shall be located at a distance of 0.2dc from the chamber wall (dc is the diameter of theflocculation chamber) at a depth of 0.5 m beneath the surface of the water.

6.60. The area of a water- whirlpool flocculation chamber shall be determined by calculating thetime the water spends in the chamber as 15-20 minutes and the chamber height, taken as 3.5-4 m.

6.61. Above flocculation chambers there shall be pavilions with a width of not over 6 m.6.62. With less than six flocculation chambers built into settling tanks, one reserve shall be

employed (Paragraphs 6.63, 6.68).

Vertical Settling Tanks

6.63. The area of the precipitation zone Fvt, m2, of a vertical settling tank without thin-layer blocksinstalled in it shall be determined using equation (9) for two periods:minimum turbidity and minimum winter water flow;maximum turbidity and maximum water flow during the same period.

The calculated area of the settling zone shall correspond to the greatest value ofFv.t. = βvol q/3.6vcNc, (9)

where q is the calculated flow for periods of maximum and minimum daily water use, m3/hr;

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vc is the calculated speed of the ascending flow, mm/s; if process study data are not available, it is taken nogreater than the rates of precipitation of suspended matter given in Table 18, considering Paragraph 6.56;Nc is the number of settling tanks in operation;βvol is a coefficient considering the volumetric use of the settling tank, the value of which is taken as 1.3-1.5(the lower limit with a ratio of diameter to height of the settling tank of 1, the upper limit with a ratio ofdiameter to height of 1.5).

Where the number of settling tanks is less than six, one reserve shall be provided.6.64. Where thin-layer blocks are installed in the settling zone the area of the settling zone is

determined on the basis of the specific loads related to the surface area of the water occupied by the thin-layer blocks: for low-turbidity and colored water treated by coagulant 3-3.5 m3/(hr⋅m2), for moderatelyturbid water 3.6-4.5 m3/(hr⋅m2), for turbid water 4.6-5.5 m3/(hr⋅m2).

6.65. The zone of accumulation and consolidation of the sediment in vertical settling tanks shall beprovided with sloping walls. The angle between the sloping walls shall be 70-80°.

Collection of sediment shall be performed without disconnecting the settling tank. The period ofoperation To, hr, between cycles of sediment clearing shall be determined by the equation

To = WsedNoδ/q(Cs – Msw), (10)where Wsed is the volume of the zone of sedimentation and consolidation of the sediment, m3;δ is the mean concentration of the solid phase of the sediment throughout the entire height of the settlingportion, g/m3, as a function of the turbidity of the water and the length of clearing cycles, as taken from thedata of Table 19;Msw is the turbidity of the water leaving the settling tank, g/m3, taken as 8 to 15 g/m3;Cs is the concentration of suspended matter in the water arriving at the settling tank, g/m3, defined by theequation

Cs = M + Kc Dc + 0.25C + Bl, (11)where M is the quantity of suspended matter in the incoming water, g/m3 (taken equal to the turbidity of thewater);Dc is the dose of coagulant as the anhydrous product, g/m3;Kc is a coefficient taken for purified aluminum sulfate as 0.5, for a nepheline coagulant as 1.2, for ferricchloride—0.7;C is the color index of the incoming water, degrees;Bl is the quantity of insoluble substances introduced with the lime, g/m3, determined by the equation

Bl = Dl/Kl – Dl, (12)where Kl is the fractional content of CaO in the lime,

Dl is the dose of lime as CaO, g/m3.

Table 19Turbidity of

incoming water,mg/L

Reagents used Average concentration of solid phase in sediment throughheight of sedimentary portion of settling tank, g/m3, with

sediment clearing cycle length, hr6 12 24 and more

up to 50 Coagulant 9,000 12,000 15,000From 50 to “ 12,000 16,000 20,000“ 100 “ “ 20,000 32,000 40,000“ 400 “ “ 35,000 50,000 60,000“ 1000 “ “ 80,000 100,000 120,000Over 1500 Flocculant 90,000 140,000 160,000Over 1500 No reagents 200,000 250,000 300,000

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Note: When the incoming water is treated with coagulants and flocculants the mean concentration ofsolid phase in the sediment shall be taken as 25% more for low-turbidity colored water and 15% morefor moderately turbid water.

The operating period of the settling tank between cycles of clearing the sediment shall be no lessthan 6 hours.

6.66. Collection of clarified water in vertical settling tanks shall be performed using peripheral andradial grooves with apertures or with triangular notches.

The cross section of the grooves shall be calculated for a speed of movement of the water of 0.5-0.6 m/s.

Horizontal Settling Tanks

6.67. Horizontal settling tanks shall be designed with water intake distributed over the area.Settling tanks shall be designed for two periods as in Paragraph 6.63.

The area of horizontal settling tanks in plan Fhs, m2, shall be determined by the equationFh.s. = αvolq/3.6U0, (13)

where q is the design water flow, m3/hr, taken in accordance with Paragraph 6.63;U0 is the rate of precipitation of the suspended matter, mm/s, taken from Table 18;αvol is the coefficient of volumetric use of the settling tanks, taken as 1.3.

If thin-layer blocks are installed in the settling zone the area of the settling tank shall be determinedas in 6.64. These blocks shall be provided over the entire length of the settling tank.

6.68. The length of settling tanks L, m, shall be determined by the equationL = HavvavU0, (14)

where Hav is the average height of the settling zone, m, taken as 3-3.5 m depending on the height plan of thetreatment plant;vav is the calculated speed of horizontal movement of the water at the upstream end of the settling tank,taken as 6-8, 7-10 and 9-12 mm/s for slightly turbid, moderately turbid and turbid water, respectively.

The settling tank shall be divided by longitudinal barriers into independently operating sectionswith a width of not over 6 m.

Where there are less than six sections, one reserve section shall be provided.6.69. Horizontal settling tanks shall be designed with mechanical or hydraulic removal of the

sediment (without turning off the water feed into the settling tank) or a hydraulic system shall be providedto wash down the sediment with periodic interruption of the water feed into the settling tank in the case ofclarification of turbid water resulting in the formation of low-mobility sediments. A pipe with valves for theattachment of hoses shall be provided for washing down the walls and bottom of settling tanks.

6.70. For settling tanks with mechanized removal of sediment by scraper mechanisms the volumeof the zone of accumulation and consolidation of the sediment shall be determined as a function of thedimensions of the scrapers used to scrape down the sediment into the pit.

With hydraulic removal or pressure washdown of sediment the volume of the zone of accumulationand consolidation of the sediment Wsed shall be determined from equation (10) with operating time of thetank between cleanouts of no less than 12 hours.

The mean concentration of consolidated sediment shall be determined from Table 19.6.71. For hydraulic removal of sediment, a system of perforated pipe shall be provided permitting

its removal within 20-30 minutes.The bottom of the settling tank between the pipes of the sediment intake system shall be flat or

prismatic with a slope angle of the faces of 45°.The distance between axes of the pipes shall be not over 3 m with a prismatic bottom and 2 m with

a flat bottom.

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The rate of motion of the sediment at the end of the pipe shall be taken as no less than 1 m/s; in theapertures—1.5-2 m/s; the diameter of the apertures shall be no less than 25 mm, the distance betweenapertures 300-500 mm.

The apertures shall be directed alternately downward at an angle of 45° to the pipe axis.The ratio of the total area of all apertures to the cross-sectional area of the pipe shall be taken as

0.5-0.7.At the intake part of the pipe there shall be an aperture with a diameter of no less than 15 mm for

air exhaust.Hydraulic design of the sediment collection system shall be performed in accordance with

Paragraph 6.86.6.72. Pressurized hydraulic sediment washdown systems, including telescopic perforated pipe with

fittings, pump, wash water tank and tank for collection and consolidation of sediment before it istransferred to the dewatering facility, shall be designed to remove heavy, difficult sediment formed uponclarification of turbid and highly turbid water from the settling tanks.

6.73. The height of settling tanks shall be determined as the sum of the heights of the settling zoneand the sediment accumulation zone considering the additional height of the structure above the designwater level to be at least 0.3 m.

6.74. The quantity of water discharged from a settling tank together with the sediment shall bedetermined considering the following dilution factors:1.5 for hydraulic removal of sediment;1.2 for mechanical removal of sediment;2-3—with pressurized washdown of sediment.

With hydraulic sediment removal the longitudinal bottom slope of the settling tank shall be no lessthan 0.005.

6.75. The collection of clarified water shall be through a system of horizontal perforated pipe orgrooves with apertures or triangular water intake slots located over 2/3 of the length of the settling tankbeginning at the rear end wall, or over the entire length of a settling tank which is equipped with thin-layerblocks.

The speed of movement of clarified water in the end of the grooves and tubes shall be taken as 0.6-0.8 m/s, in the apertures—1 m/s.

The top of a groove with underwater apertures shall be 10 cm higher than the maximum waterlevel in the settling tank, the immersion of a pipe beneath the water level shall be determined by hydrauliccalculation.

The apertures in a groove shall be 5-8 cm above the bottom of the groove, in pipes—horizontallyon the axis. The diameter of the apertures shall be no less than 25 mm.

Drainage of water from grooves and pipes into the collecting pocket shall be free (not flooded).The distance between groove or pipe axes shall be not over 3 m.6.76. The covers over settling tanks shall provide hatches to allow entry into the settling tanks,

sampling apertures at a distance of not over 10 m from each other and ventilating pipes.Clarifiers with Suspended Sediment

6.77. The design of clarifiers shall be performed considering annual fluctuations in the quality ofthe water treated.

If there are no data available from process studies the rate of ascending flow in the clarificationzone and the water distribution factor between the clarification zone and the sediment removal zone Kwd

shall be taken from the data of Table 20 considering the note to Table 18.

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Table 20Turbidity of water

entering clarifier, mg/LRate of ascending water flow in clarification zone

vclr, mm/sWater distribution

factor Kwd

Winter SummerFrom 50 to 100 0.5-0.6 0.7-0.8 0.7-0.8From 100 to 400 0.6-0.8 0.8-1 0.8-0.7From 400 to 1000 0.8-1 1-1.1 0.7-0.65From 1000 to 1500 1-1.2 1.1-1.2 0.64-0.6Note: Lower limits of vclr given for domestic-/drinking-water lines.

6.78. The maximum values of areas obtained in calculation for two periods according to Paragraph6.63 shall be used for the clarification and sediment removal zones.

The area of the clarification zone Fclr, m2, shall be determined by the equationFclr = qKw.d.3.6σclr, (15)

where Kw.d. is the water distribution coefficient between the zones of clarification and sediment removal (bysediment thickener), taken from Table 20;vclr is the speed of the ascending water flow in the clarification zone, mm/s, according to Table 20.

The area of the sediment removal zone Frem, m2, shall be determined by the equationFrem = q(1 – Kw.d.)/3.6vclr. (16)

When thin-layer blocks are installed in the precipitation and sediment removal zones the area of thezones occupied by the blocks shall be determined in accordance with Paragraph 6.64.

6.79. The height of the suspended sediment layer shall be taken as 2 to 2.5 m. The bottom of thesediment intake windows or edge of the sediment discharge pipes shall be 1-1.5 m higher than the transitionof the slanted walls of the suspended sediment zone of the clarifier to vertical.

The angle between the slanted walls in the bottom portion of the suspended sediment zone shall be60-70°.

The height of the clarification zone shall be taken as 2-2.5 m.The distance between collecting troughs or pipes in the clarification zone shall be no less than 3 m.The wall height of clarifiers shall exceed the design water level in the clarifiers by 0.3 m.6.80. The volume of the zone of accumulation and consolidation of sediment shall be determined by

equation (10), the consolidation time shall be taken as no less than 6 hours for a plant without individualsediment thickeners and 2-3 hours with thickeners and automation of sediment drainage.

6.81. Removal of sediment from sediment thickeners shall be performed periodically by perforatedpipes. The quantity of water discharged with the sediment shall be determined from Table 19 consideringthe sediment dilution factor, taken as 1.5.

6.82. The distribution of water over the area of the clarifier shall be performed with perforatedpipes, laid at a distance of not over 3 m from each other.

The speed of movement of the water entering the perforated pipes shall be 0.5-0.6 m/s, the speed ofexit from the holes in the perforated pipes—1.5-2 m/s. The diameter of the aperture shall be no less than 25mm, distance between apertures not over 0.5 m, apertures shall be located downward at an angle of 45° tothe vertical on both sides of the pipe alternately.

6.83. The speed of movement of water with sediment in the sediment intake windows shall be 10-15 mm/s, in sediment discharge pipes 40-60 mm/s (higher values relate to water containing primarilymineral suspended matter).

6.84. Collection of clarified water in the clarification zone shall be by the use of grooves withtriangular water intakes 40-60 mm high, with distance between water intake axes 100-150 mm and anglebetween water intake edges 60°. The design speed of movement of water in the grooves shall be 0.5-0.6m/s.

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6.85. Collection of clarified water from the sediment accumulator shall be by submerged perforatedpipes.

In vertical sediment thickeners the top of the perforated collecting pipe shall be no less than 0.3 mbelow the water level in clarifiers and no less than 1.5 m above the top of the sediment intake windows.

In sump sediment thickeners the perforated collecting pipe used to carry away clarified water shallbe located beneath the cover. The diameter of the pipe used to carry away clarified water shall bedetermined based on a speed of movement of the water of not over 0.5 m/s, speed of entry of water intopipe apertures no less than 1.5 m/s, aperture diameter 15-20 mm.

In collecting pipes, valves shall be installed where they enter a collecting channel.The difference in level between the bottom of a collecting pipe and the water level in the common

collecting channel of a clarifier shall be no less than 0.4 m.6.86. The head loss, m, in perforated distributing and collecting pipe and grooves for water and

sediment shall be determined on the basis of the maximum speed of movement of water in them usingequation (8) or (22), taking the hydraulic resistance factors as follows:

ζ = +2 2 12. Kp —for a straight distributing pipe or collector with branches having circular apertures;

ζ = +4 12Kp —same, but with slots;

ζ = 33 18. .Kp —for a straight collecting pipe operating in full cross section;

ζ = +32 31 7. .K p —for a collecting groove with free water surface and submerged apertures;

where Kp is the coefficient of perforation—the ratio of the total area of apertures or slots to the cross-sectional area of the straight pipe or collector or to the available cross section at the end of a collectinggroove, 0.15 ≤ Kp ≤ 2.

The head loss in lines before and after perforated sections of pipes and grooves, as well as localhydraulic resistances in these sections shall be additionally considered.

The head loss in a layer of suspended sediment shall be taken as 0.01-0.02 m water per m ofheight.

6.87. Pipes for sediment removal from a sediment thickener shall be designed to carry away theaccumulated sediment in no more than 15-20 minutes. The diameter of pipes for sediment removal shall beno less than 150 mm. The distance between the walls of neighboring pipes or channels shall be no less than3 m.

The average rate of movement of sediment in the apertures of perforated pipe shall be not over 3m/s, the speed at the end of the perforated pipe no less than 1 m/s, the diameter of apertures no less than 20mm, the distance between apertures not over 0.5 m.

6.88. The angle between the inclined walls of sediment thickeners shall be taken as 70°.When clarifiers with sump sediment thickeners are used the hatch connecting the zone of suspended

sediment to the sediment thickener shall be equipped with a device which automatically opens when thewater level in the clarifier drops below the top of the sediment discharge pipe (during sediment drainageand emptying).

6.89. Where the number of clarifiers is less than six, one reserve clarifier shall be employed.

Facilities for Clarification of Highly Turbid Water

6.90. Highly turbid water shall be clarified by two-stage settling with treatment of the water byreagents before the first and second stages.

First-stage settling tanks shall be radial settling tanks with scrapers on rotating beams or horizontalsettling tanks with chain scraper mechanisms. It is permissible to use a hydraulic washdown system for

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removal of sediment. With justification it is permissible to use a floating water intake-clarifier with thin-layer elements as the first stage without reagents.

6.91. The forms and doses of reagents introduced to the water before settling tanks in the first andsecond stages shall be determined on the basis of process studies.

6.92. Flocculation chambers in horizontal settling tanks used for clarification of highly turbidwater shall generally be of mechanical type. Flocculation chambers shall not be provided before radialsettling tanks. Horizontal settling tanks shall be designed in accordance with Paragraphs 6.67-6.76.

6.93. The area of radial settling tanks Fr.s., m2, when used for the first stage of settling of highlyturbid water, shall be determined by the equation

Fr.s. = 0.2(q/u0)1.07 + f, (17)

where q is the design flow rate, m3/hr;u0 is the rate of precipitation of the suspended matter, taken as 0.5-0.6 mm/s;f is the area of the eddy zone of the radial settling tank, the radius of which is taken as 1 m greater than theradius of the distributing device, m2.

The bottom of the central distributing device is made plugged, its top at a depth equal to the heightof the water layer next to the peripheral wall; its radius shall be 1.5-2.5 m. The area of apertures in the sidewall of the water distributing device shall be determined by calculating the rate of movement of waterthrough it as 1 m/s with an aperture diameter of 40-50 mm.

Collection of clarified water shall be performed by a peripheral groove with submerged aperturesor triangular drains as in Paragraph 6.84.

6.94. The mean concentration of thickened sediment in a first-stage settling tank shall be taken as150-160 g/L.

Rapid Filters

6.95. Filters and their connecting lines shall be designed to operate in normal and forced (a portionof the filters in repair) modes. In plants with up to 20 filters, it shall be possible to shut down one filter forrepair, in plants with a greater number of filters—two filters.

6.96. Filters shall be charged with quartz sand, crushed anthracite and claydite, as well as othermaterials. All filtering materials shall support the process and have the required chemical resistance andmechanical strength. The requirements of Paragraph 1.3 shall be satisfied for domestic-/drinking-watersupply.

6.97. The rates of filtration in normal and forced modes with no process study data available shallbe taken from Table 21 considering the need to support an operating time of the filters between washingcycles of no less than: in normal mode—8-12 hours, in forced mode or with full automation of filterwashing—6 hours, assuring satisfaction of the requirements of GOST 2874-82 for domestic-/drinking-water lines.

6.98. The total area Ff, m2, shall be determined by the equationFf = Q/(Tplvn – nwqw – nwτwvc), (18)

where Q is the productive throughput of the treatment plant, m3/day;Tpl is the time of operation of the plant during the course of one day, hr;vn is the calculated filtration rate in normal mode, m/hr, taken from Table 21, considering the calculationsaccording to equation (20);nw is the number of washings of one filter per day in the normal operating mode;qw is the specific consumption of water for one washing of one filter, m3/m2, taken considering Paragraph6.110;τw is the downtime of a filter in connection with its washing, taken for filters washed with water as 0.33 hr,for filters washed with water and air—0.5 hr.

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Note: With water and air washing, the value of qw is defined as the sum of the corresponding quantities forthe individual washing stages.

6.99. The number of filters per plant with throughput over 1600 m3/day shall be no less than four.With a plant throughput of over 8-10 thousand m3/day the number of filters shall be determined byrounding to the nearest integer (even or odd depending on the filter configuration) in the equation

N Ff f= 2. (19)

The following equation shall be satisfiedvf = vnNf/(Nf – N1), (20)

where N1 is the number of filters in repair (see Paragraph 6.95);vf is the filtration rate in forced mode, which shall be no less than that given in Table 21.

The area of one filter shall be not over 100-120 m2.6.100. The maximum head losses in a filter shall be taken for open filters as 3-3.5 m depending on

filter type, for pressurized filters as 6-8 m.6.101. The height of the water layer over the surface of the charge in open filters shall be at least 2

m; the height of the structural equipment over the design water level—at least 0.5 m.

Table 21Characteristics of filtering layer Filtration rate,

m/hr

Filters Chargematerial

Grain diameter, mm Nonuni-formity

of

Layerheight,

m

Normalmode,

vn

Forcedmode, vf

Mini-mum

Maxi-mum

Equiva-lent

charge

Single-layer rapidfilters with chargesof various particlesizes

Quartz sand 0.50.70.8

1.21.62

0.7-0.80.8-11-1.2

1.8-21.6-1.81.5-1.7

0.7-0.81.3-1.51.8-2

5-66-88-10

6-7.57-9.510-12

Crushedclaydite

0.50.70.8

1.21.62

0.7-0.80.8-11-1.2

1.8-21.6-1.81.5-1.7

0.7-0.81.3-1.51.8-2

6-77-9.59.5-12

7-98.5-11.512-14

Rapid filters withtwo-layer charge

Quartz sand 0.5 1.2 0.7-0.8 1.8-2 0.7-0.8

Crushedclaydite oranthracite

0.8 1.8 0.9-1.1 1.6-1.8 0.4-0.5 7-10 8.5-12

Notes: 1. Calculated filtration rates within these limits can be used depending on water quality in watersupply source, process of its treatment before filtering and other local conditions. When water is treatedfor domestic-/drinking- purposes, lower values of filtration rates shall be used.2. Single-layer rapid filters with charge particle size 0.8-2 mm shall be used only for industrial processwater supply.3. Deviations in filter charge particle size within limits of up to 10% are permitted.4. When filtering materials not mentioned in Table 21 are used, recommended parameters shall berefined on the basis of experimental data or usage experience.5. Equivalent grain diameter dg, mm, shall be determined by the expression:dg = 100/Σ (Pi/di),where Pi is the percent content of fractions with mean grain diameter di, mm.6. Charge heterogeneity factor is equal to: Kch = d80/d10,

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where d10 is the diameter of charge grains, mm, for which 10% of total mass passes through screenapertures;d80 is the diameter of charge grains, mm, for which 80% of total mass passes through screen apertures.7. When filters are used in two-stage filtration water treatment systems the filtration rate shall be takenas 10-15% higher.8. When charges of crushed claydite and anthracite are used, water-air washing is not permitted.

6.102. When some of the filters are out of use for washing, the filtration rate on the remainingfilters shall be maintained constant or increased; however, the filtration rate shall not exceed the value of vf

indicated in Table 21. When filters operate at constant filtration rate, the additional height Hadd shall beprovided above the normal water level, as determined by the equation

Hadd = W0/ΣFf, (21)where W0 is the volume of water, m3, accumulated during the downtime of the filters in washing;ΣFf is the total area of filters, m2, in which the water is accumulated.

In forced mode the speed of movement of water in pipes (feeding and draining filtrate) shall be notover 1-1.5 m/s.

6.103. Pipe distributing (drain) systems with high resistance shall be used with water dischargeinto supporting layers (of gravel or similar material) or directly into the mass of the filtering layer. Thepossibility shall be provided of cleaning out the distributing system, and in collectors more than 800 mm indiameter, of their inspection.

Table 22Particle size, mm Layer height, mm

40-20 Upper limit of layer shall be at level of top ofdistributing pipe, but no less than 100 mm above

apertures20-10 100-15010-5 100-1505-2 50-100

Notes: 1. With water-air washing with air fed in through pipe system height of layers with particle size10-5 mm and 5-2 mm shall be taken as 150-200 mm each.2. For filters with charge particle size less than 2 mm, an additional supporting layer with particle size2-1.2 mm and height 100 mm shall be provided.

6.104. The particle size of the fractions and the height of the supporting layers with distributionsystems of high resistance shall be determined from Table 22.

6.105. The following are required with branched pipe drainage: with supporting layers present—apertures 10-12 mm in diameter, with such layers absent—slots with width 0.1 mm less than the minimumgrain size of the filtering charge. The total area of apertures shall represent 0.25-0.5% of the operating areaof the filter; the area of slots shall be 1.5-2% of the operating area of the filter. Apertures shall be placed intwo alternating rows at an angle of 45° downward from the vertical. Slots shall be placed uniformly acrossthe axis and around the perimeter of the pipe in no less than two rows.

The distance between branch pipes shall be 250-350 mm, between apertures 150-200 mm, betweenslots no less than 20 mm, from the bottom of branches to the bottom of the filter 80-120 mm.

The loss of head in the distributing system shall be determined by the equation

h v g v g= +ζ c a.e.22 2 2 , (22)

where vc is the speed at the beginning of the collector, m/s;va.e. is the average speed at the entry to a branch, m/s;ζ is the hydraulic resistance factor, taken as described in Paragraph 6.86.

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The head loss in the distributing system when the filter is washed shall not exceed 7 m of water.6.106. The cross-sectional area of the collector of a distributing pipe system shall be constant over

its length. The speed of motion of the water during washing shall be taken as: at the beginning of thecollector 0.8-1.2 m/s, at the beginning of the branches 1.6-2 m/s.

The design of the collector shall allow for placement of branches horizontally at identical spacing.6.107. It is permitted to use a distributing system without supporting layers in the form of channels

placed perpendicular to the collector (discharge channel) and covered on top with polymer concrete slabsno less than 40 mm thick.

6.108. A distributing system with nozzles shall be used where water and air washing is used; thenumber of nozzles shall be 35-50 per square meter of operating surface of the filter.

The head loss in slot nozzles is determined by equation (8), taking the speed of movement of thewater or water-air mixture in the slots of the nozzles as no less than 1.5 m/s and the resistance factor as ζ =4.

6.109. To remove air from a pipe feeding water for washing of filters, air risers 75-150 mm indiameter shall be provided with fittings or automatic devices for releasing air; a filtrate collector shall alsohave air risers 50-75 mm in diameter, the number of which shall be one for a filter area of up to 50 m2, twowith larger filter area (at the beginning and end of the collector), with valves or other devices to release airon the risers.

A pipe feeding water for washing of filters shall be located beneath the edges of the filter grooves.Emptying of a filter shall be performed through the distributing system and a separate discharge

pipe 100-200 mm in diameter (depending on filter area) with a gate valve.6.110. The filter charge shall be washed using water which has been filtered. It is permissible to

use washing from above with the distributing system above the surface of the filter charge.The parameters of the wash water for a quartz sand charge are listed in Table 23.

Table 23Filters and their charges Wash intensity,

L/(s⋅⋅⋅⋅m2)Wash time, min Relative charge

expansion, %Rapid with single-layer charge,diameter D, mm:

0.7-0.8 12-14 450.8-1 14-16 6-5 301-1.2 16-18 25

Rapid with two-layer charge 14-16 7-6 50Notes: 1. Higher intensity washing corresponds to shorter times.2. With nonmobile top washing device intensity shall be 3-4 L/(s⋅m2), head 30-40 m. Washing time 5-8 minutes, ofwhich 2-3 minutes precede bottom washing. Distributing pipes shall be located 60-80 mm from charge surfaceeach 700-1000 mm. Distance between apertures in distributor pipes or between nozzles shall be 80-100 mm. Withrotating device washing intensity shall be 0.5-0.75 L/(s⋅m2), head 40-45 m.

With a claydite charge washing intensity shall be 12-15 L/(s⋅m2) depending on the type of claydite(greater intensity for denser claydite).

6.111. Wash water shall be collected and carried away in grooves of semicircular or pentagonalcross section. The distance between axes of neighboring grooves shall be not over 2.2 m. Groove width Bgrv

shall be determined by the equation

( )B K q a sicgrv grv grv2

grv+ 15735 . ,[ ]+ (23)

where qgrv is the flow rate of water through the groove, m3/s;agrv is the ratio of the height of the rectangular portion of the groove to half its width, taken as 1 to 1.5;

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Kgrv is a coefficient which is taken as follows: for grooves with semicircular shape—2, for pentagonalgrooves—2.1.

The edges of all grooves shall be at the same level and strictly horizontal.The troughs of the grooves shall have a slope of 0.01 toward the drainage channel.6.112. In filters with collecting channels the distance from the bottom of a groove to the bottom of

the channel Hch shall be determined by the equation

H q gBch ch2

ch2= +173 0 23. . , (24)

where qch is the flow rate of water through the channel, m3/s;Bch is the width of the channel, m, taken as no less than 0.7 m.Note: The water level in the channel, considering the head created by the pipe carrying away the washwater shall be 0.2 m below the bottom of the groove.

6.113. The distance from the surface of the filtering charge to the edges of the grooves Hg isdetermined by the equation

Hg = Hc ac/100 + 0.3, (25)where Hc is the height of the filtering layer, m;ac is the relative expansion of the filtering charge in percent, taken from Table 23.

6.114. Water-air washing shall be used for filters with a charge of quartz sand using the followingmode: blow through air at 15-20 L/(s⋅m2) for 1-2 minutes, then combined water-air washing at an air feedrate of 15-20 L/(s⋅m2) and water at 3-4 L/(s⋅m2) for 4-5 minutes with subsequent feeding of water (withoutair) at 6-8 L/(s⋅m2) for 4-5 minutes.Notes: 1. Larger-grained charges correspond to greater water and air feed intensities.2. When justified, it is permissible to use washing modes other than that described.

6.115. With water-air washing the water and air shall be fed through distributing systems withspecial nozzles using separate distributing pipe systems for the air and the water.

6.116. With water-air washing, a system of horizontal discharge of the wash water shall be usedwith a sand-trapping groove formed of two slanted walls—a water drain wall and an apron.

6.117. Water for washing shall be supplied by pumps or from a tank. Depending on the number offilters at the plant, washing systems shall be designed to wash one or several filters at one time. The volumeof the wash tank shall support one more washing cycle than the design number.

The head of water for washing of filters shall be selected considering the head lost in thedistributing system and the connecting lines feeding the wash water and the filter charge.

The pump which feeds water into the tank shall support filling of the tank in a time no greater thanthe interval between filter washings when using forced filter mode. The pump feeding water into the tankshall take water from a filtered water supply. It is permissible to pump water from a filtered water pipe ifthe intake does not exceed 50% of the discharge of filtrate.

Water taken for washing of filters shall be collected from tanks of filtered water containingsufficient water for one additional washing above the design number of washings.

The speeds of movement of water in pipes feeding and draining the wash water shall be 1.5-2 m/s.The possibility shall be prevented of sucking in air into the pipes feeding wash water to filters, or ofdrawing water into the pipes draining the wash water.Coarse-grain Filters

6.118. Coarse-grain filters shall be used for partial clarification of water utilized for productionpurposes, with and without coagulation.

6.119. Filters shall be charged using quartz sand and other materials supporting the process andhaving the required mechanical strength and chemical stability. Filter charge characteristics are presentedin Table 24.

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Table 24Charge material Charge material

particle size, mmNonuniformityfactor not over

Charge layerheight, m

Filtration speed,m/hr

Quartz sand 1-2 1.8 1.5-2 10-12Same 1.6-2.5 2 2.5-3 13-15Note: Special-design filters with floating charge of polystyrene foam may be used for partial clarification of water.

6.120. Pressure coarse-grain filters shall be designed for maximum head loss in the filter chargeand drains up to 15 m, open filters—3-3.5 m. Open filters shall have a water layer over the level of thecharge of 1.5 m.

6.121. Washing of coarse grain filters shall be performed using water and air. The water and airdistributing systems or combined water-air distributing system shall be designed in accordance withParagraphs 6.108, 6.109, 6.115-6.117 to feed water and air at the rates given in Paragraph 6.123.

6.122. Wash water drainage devices for open filters shall be made in accordance with Paragraph6.116.

6.123. When designing coarse grain filters, the following washing conditions shall be provided:loosening of the filter charge with air at 15-25 L/(s⋅m2)—1 min; water-air washing at 3.5-5 L/(s⋅m2) waterand 15-25 L/(s⋅m2) air—5 min; washing with water at 7-9 L/(s⋅m2)—3 min. The higher values of washingintensity relate to coarser charges.

6.124. The area of coarse grain filters shall be determined in accordance with Paragraph 6.98.6.125. With up to 10 filters, the possibility shall be provided of disconnecting one filter for repair,

with a greater number—two filters. The filtration rate on the filters remaining in operation shall not exceedthe maximum values given in Table 24.

Contact Clarifiers

6.126. Contact water clarification plants shall provide drum screen filters and an intake chambersupporting the required head of water, mixing and contact of the water with reagents, as well as separationof air from the water.

6.127. The volume of the intake chamber shall be determined so that the water remains in it for atleast 5 min. The chamber shall be divided into no less than 2 sections, each of which shall have overflowand drain pipes.Notes: 1. Drum screen filters shall be located above the intake chamber; their installation in a separate buildingis permissible if justified. Their design shall agree with Paragraphs 6.11-6.14.2. Mixing devices, the sequence and time interval between input of reagents shall satisfy the requirements ofParagraphs 6.40, 6.41, 6.17-6.19.The possibility shall be provided of additional reagent input after the intake chamber.

6.128. The increase in water level in intake chambers above the level in the contact clarifiers Hl, m,shall be determined by the equation

Hl = 0.8hc + hs, (26)where hc is the maximum permissible head loss in the sand layer of the charge, taken equal to the height ofits layer, m;hs is the sum of all head losses along the path of movement of the water from the beginning of the intakechamber to the charge in the clarifiers, m.

Drainage of water from intake chambers in contact clarifiers shall be performed at a level of noless than 2 m lower than the level of the water in the clarifiers. The possibility of saturating the water withair shall be prevented in chambers and in pipes.

6.129. Contact clarifiers when washed with water shall be made without supporting layers, whenwashed with water and air—with supporting layers.Contact clarifiers shall be charged as noted in Table 25.

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6.130. The filtration rates in contact clarifiers shall be as follows:without supporting layers in normal operating mode—4-5 m/hr, in forced mode—5-5.5 m/hr; withsupporting layers in normal mode 5-5.5 m/hr, in forced mode—5.5-6 m/hr.

When treating water for domestic-/drinking-water use, the lower values of filtration rates shall beused.

Table 25Characteristic Height of gravel and sand layers, m, for clarifiers

without supporting layers with supporting layersGrain size of gravel and sand,mm:

40-20 — 0.2-0.2520-10 — 0.1-0.1510-5 — 0.15-0.25-2 0.5-0.6 0.3-0.42-1.2 1-1.2 1.2-1.31.2-0.7 0.8-1 0.8-1

Equivalent sand grain diameter,mm

1-1.3 1-1.3

Notes: 1. For contact clarifiers with supporting layers the upper boundary of gravel with particle size 40-20 mmshall be at the level of the top of the distributing system pipes. The total height of the charge shall be not over 3 m.2. Contact clarifiers shall be charged with gravel and quartz sand, as well as other materials satisfying therequirements of Paragraph 6.96 with density 2.5-3.5 g/cm3.

It is permissible to provide for operation of contact clarifiers with variable filtration speed,decreasing toward the end of the cycle, if the average speed is equal to the design speed.

6.131. The total area of contact clarifiers Fc.c., m2, shall be determined considering the discharge ofthe first filtrate according to the equation

Fc.c = Q/[Tplvn – nw(qw + τwvn + τplvn/60)], (27)where τpl is the time of discharge of the first filtrate, min, taken in accordance with Paragraph 6.133, andthe other symbols are as in equation (18).

The number of clarifiers per plant shall be determined in accordance with 6.99.6.132. Washing shall be performed with treated water. It is permissible to use untreated water

under the following conditions: turbidity of the water not over 10 mg/L, coli-index—up to 1000 units/L,preliminary treatment of water on drum screens (or microfilters) and purification. When treated water isused, the stream shall be broken before feeding water into the wash water storage tank. Direct transfer ofwash water from filtered water pipes and tanks is not permitted.

6.133. The conditions of washing of contact clarifiers are listed in Table 26.Table 26

Characteristic Unit of measure ValueWashing time min 7-8Water feed rate L/(s⋅m2) 15-18Discharge time of first filter whenwashing with:

treated water min 10-12untreated (see Paragraph 6.132) min 12-15Water-air washing of contact clarifiers shall be performed with the following mode: loosening of

the charge with air at 18-20 L/(s⋅m2) for 1-2 min; joint water-air washing with air feed rate 18-20 L/(s⋅m2)and water feed rate 3-3.5 L/(s⋅m2) for 6-7 min; additional washing with water at 6-7 L/(s⋅m2) for 5-7 min.

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The drainage time of the first filter for washing with water is, min:treated—5-10;untreated—10-15.

6.134. In contact clarifiers with supporting layers and water-air washing, pipe distributing systemsshall be used to feed in water and air, with a horizontal wash water discharge system.

In contact clarifiers without supporting layers, the distributing system shall have side flaps weldedalong the perforated pipes, between which there shall be welded transverse barriers, dividing the spacebeneath the pipes into cells. The apertures in the perforated pipes shall be located in two alternating rowsand shall be directed downward at an angle of 30° to the vertical axis of the pipe. The diameter of theapertures shall be 10-12 mm, distance between axes in a row—150-200 mm. The distributing system shallbe designed in accordance with Table 27.

Table 27Branch pipe Ratio of total Distance, mm

diameter, mm area ofapertures to

clarifier area,%

betweenbranch pipe

axes

from bottomof clarifier to

bottom offlaps

from bottomof flaps to axes

of branchpipes

betweentransversebarriers

75 0.28-0.3 240-260 100-120 155 300-400100 0.26-0.28 300-320 120-140 170 400-600125 0.24-0.26 350-370 140-160 190 600-800150 0.22-0.24 440-470 160-180 220 800-1000

Notes: 1. The speed of movement of water at the branch pipe inlets during washing shall be 1.4-1.8 m/s.2. Greater distances between pipe axes correspond to greater distances from the bottom of the clarifier to thebottom of the flaps.

6.135. In contact clarifiers without supporting layers, wash water shall be drained by grooves as inParagraphs 6.111-6.113. Above the edges of the grooves there shall be plates with triangular notcheshaving heights and widths of 50-60 mm, with distances between their axes of 100-150 mm.

6.136. Channels and lines for feed and drainage of water, tanks and pumps for washing of contactclarifiers shall be designed in accordance with Paragraphs 6.107, 6.109 and 6.117, with the bottom of theoutlet feeding the clarified water from the contact clarifiers 100 mm higher than the level of the water in thecollecting channel used in washing.

The pipes used to drain clarified and wash water shall be placed at levels eliminating the possibilityof flow into the clarifiers during the operating cycle and during washing.

A pipe with a valve having a diameter sufficient to support a descending water flow in the clarifierof not over 2 m/hr with supporting layers and not over 0.2 m/hr without supporting layers shall be providedin the lower portion of the collector of the distributing system in order to empty contact clarifiers. Duringemptying of clarifiers without supporting layers, devices shall be provided to prevent loss of the charge.Slow Filters

6.137. The design filtration speeds of slow filters shall be within limits of 0.1-0.2 m/hr, with speedsof over 0.1 m/hr to be used only during washing of the filter.

The number of filters shall be no less than three. The width of a filter shall be not over 6 m, itslength—not over 60 m.

The particle size and height of the charge layers in such filters shall be as noted in Table 28.

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Table 28Layer number

from top tobottom

Charging material Grain size, mm Charge layerheight, mm

1 Sand 0.3-1 5002 Sand 1-2 503 Sand 2-5 504 Gravel or rubble 5-10 505 Gravel or rubble 10-20 506 Gravel or rubble 20-40 50

6.138. Slow filters shall be designed with mechanical or hydraulic regeneration of the sand charge.The flow of water per one cycle of washing contaminants from 1 m2 of filter charge surface shall

be 9 L/s, the length of the washing cycle for each 10 m of filter length shall be 3 min.6.139. Water for regeneration of a slow filter shall be provided by a special pump or tank. It is

permissible to regenerate the filter by forcing the throughput of the pumps which feed water forclarification or by partial use of the capacity of filters operating in filtration mode.

6.140. The layer of water above the surface of the charge of slow filters shall have a thickness of1.5 m. When there is a cover above the filters the distance from the surface of the charge to the cover shallbe sufficient to support operation in regeneration mode, as well as changing and washing the charge.

Drains of perforated pipe, brick or concrete slabs laid with spaces between them, porous concrete,etc. shall be installed.

Contact Prefilters

6.14l. Contact prefilters shall be used with two-stage filtration for preliminary treatment of waterbefore rapid filters (second stage).

The design of contact prefilters is similar to the design of contact clarifiers with supporting layersand water-air washing; as they are planned, Paragraph 6.126-6.136 shall be consulted. The area ofprefilters shall be determined considering the throughput of water for washing of the rapid second-stagefilter.

6.142. When there are no process instructions, the basic parameters of contact prefilters shall be asfollows:height of sand layers with grain size, mm:5-2 0.5-0.6 m2-1 2-2.3 mequivalent diameter of sand grains 1.1-1.3 mmfiltration rate in normal mode 5.5-6.5 m/hrfiltration rate in forced mode 6.5-7.5 m/hr

6.143. Mixing of the filtrate of simultaneously operating contact prefilters shall be provided beforeit is fed to the rapid filters.

WATER PURIFICATION

6.144. The selection of a method for water purification shall be made considering the consumptionand quality of water, effectiveness of its treatment, conditions of delivery, transportation and storage ofreagents, the possibility of automating processes and mechanizing labor-consuming operations.

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6.145. The introduction of chlorine-containing reagents for water disinfection shall be performed inpipes before purified water tanks.The need to purify ground water shall be determined by agencies of the sanitary-epidemiological service.Note: When justified, it is permissible to use special contact tanks to support contact of chlorine-containingreagents with water.

6.146. The dose of active chlorine required to disinfect water shall be established on the basis ofprocess testing data. If such data are not available, in preliminary calculations for surface water afterfiltration a figure of 2-3 mg/L may be used, for water from underground sources 0.7-1 mg/L.

The concentrations of residual free and bonded chlorine shall be taken in accordance with GOST2874-82.Note: When water to be used for drinking and domestic purposes is stored in tanks for the period when one of themis disconnected for washing and repair in cases when the time of contact of the water with chlorine is notprovided, twice the normal dose of chlorine shall be administered. The increased dose of chlorine may beprovided by the use of reserve chlorinators.

6.147. The chlorine section shall support reception, storage and evaporation of liquid chlorine,measurement of gaseous chlorine to produce chlorine water.

Chlorine water shall be fed separately to each input point.The chlorine section shall be located in separately standing chlorine facilities, which shall also

contain the service chlorine storage facility, evaporator and chlorine dosing facilities. The service chlorinestorage facility may be located in separate buildings or may be adjacent to the chlorine dosing andsupplementary chlorine section rooms (compressor and ventilator rooms, etc.); it shall be separated fromother rooms by a continuous wall having no openings.

6.148. Service chlorine storage facilities shall be planned in accordance with Paragraphs 6.211 and6.212. When justified, a separate chlorine storage facility may not be provided; in this case, one liquidchlorine storage cylinder with a net mass of not over 70 kg may be present in the chlorine dosing area.

6.149. Chlorine evaporators shall be placed in the chlorine storage facility or chlorine dosing area.Chlorine shall be evaporated in special evaporators or cylinders (in which the chlorine is delivered).

The temperature of the water fed into the evaporator shall be within the limits of 10-30°C, and thedecrease in water temperature in the evaporator shall be not over 5°C.

The evaporator shall be equipped with devices to monitor the water temperature and the pressureof the chlorine and water. When gaseous chlorine is fed outside the building, devices shall be installed afterthe evaporator to purify the gas, as well as a valve to maintain a vacuum such that the chlorine will notcondense at the lowest ambient air temperature.

The length of the gaseous chlorine pipe shall not exceed 1 km.6.150. Chlorine dosing facilities without evaporators, located in facilities connected to other water

supply buildings or supplementary chlorine section rooms shall be separated from other rooms by acontinuous wall having no openings and equipped with two external exits, one of which has a double door.All doors shall open outward. The floor of the chlorine dosing section, if located above other rooms, shallbe impervious to gas. Chlorine dosing sections may not be located in rooms with floors below ground level.

6.151. Automatic vacuum chlorinators shall be used for chlorine dosing purposes.The calculated flow rates and heads of water fed to the chlorinator and the pressure of the chlorine

water downstream from the chlorinator shall be determined based on the characteristics of the chlorinator,as well as its location relative to the point where the chlorine is added.

It is permissible to use a manually controlled chlorinator in which the chlorine feed is monitored byweight.

6.152. The number of reserve chlorinators per chlorine addition point shall be taken as: with 1-2operating chlorinators—1, with more than two—2.

It is permissible to provide common reserve chlorinators for two chlorine addition points.

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It is not permitted to operate two or more chlorinators with jet-type ejectors with one chlorine waterpipe.

6.153. Chlorine lines for the transportation of liquid and gaseous chlorine shall be made ofseamless steel pipe.

The number of chlorine lines shall be no less than two, one of which is a reserve line.Chlorine lines and fittings on the lines shall be designed for an operating pressure of 1.6 MPa (16

kgf/cm2) and a test pressure of 2.3 MPa (23 kgf/cm2).Chlorine lines passing through rooms shall be placed in brackets mounted on walls and columns;

out of doors—on trestles with protection from direct sunlight. Chlorine lines shall be painted with vinylperchloride enamel. Joints shall be welded or made with sleeves, the ends of which are welded, or flangeshaving “rib-slot” sealing surfaces using chlorine-resistant gaskets (Paronite [rubberized asbestos fabric])and stainless steel bolts.

Liquid chlorine pipes shall have a slope of 0.01 in the direction of the chlorine vessel, and chlorinelines shall have no places where a hydraulic seal or gas plug may form.

The diameter of chlorine lines shall be determined by the design flow of chlorine with a factor of 3considering the volumetric mass of liquid mass of chlorine as 1.4 metric ton/m3, of gaseous chlorine 0.0032metric ton/m3, speed of movement in pipes 0.8 m/s for liquid chlorine, 2.5-3.5 m/s for gaseous chlorine.The diameter of a chlorine line shall be no more than 80 mm.

A device shall be provided to remove gaseous chlorine from the system when changing a containeror cylinder, and also for periodic removal of nitrogen trichloride from pipes and evaporators. It isrecommended to use dry compressed nitrogen, air, etc.

The products blown through shall be rendered harmless by passing them through a layer ofneutralization solution.

6.154. Pipes for chlorine water shall be made of materials having corrosion resistance to it: rubber,high density polyethylene, polyvinyl chloride, etc. In rooms, chlorine water pipes shall be placed inchannels cut into the floor or on brackets on continuous supports.

Out of doors, chlorine water pipes shall be buried in channels or sheaths of corrosion-resistantpipe.

Other types of pipes except for those used to warm the chlorine water pipes may not be placed inthe same channels or sheaths.

Temperature compensation of pipes is required, and it shall be possible to change the pipes in thesheaths and channels.

Manholes shall be provided for outdoor chlorine water pipes, in which the sheaths are interrupted,to allow observation of possible chlorine water leakage. The bottoms of the manholes shall be covered withchemically stable enamel. The distance between manholes shall be no greater than 30 m.

The depth of the bottom of the sheath shall be no less than the depth to which the ground freezesunless the sheath is warmed.

6.155. Air exhausted into the atmosphere by constantly operating ventilation systems in chlorinestorage facilities and dosing areas shall be exhausted through a pipe, the height of which is determined inaccordance with Paragraph 14.38.

When necessary, as determined by calculation, the air exhausted by the ventilators shall bedecontaminated.

When chlorine containers are stored, decontamination of air in an emergency shall be provided.The concentration of chlorine in the air exhausted by ventilators in an emergency shall be determined forthe area of chlorine leakage from one container and an evaporation rate from the floor surface of 5-6kg/(hr⋅m2).

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6.156. Irrigated scrubbers at least 3 m in height shall be used to cleanse the air, the rate ofmovement of the air shall be not over 1.2 m/s, irrigation rate no less than 20 m3/(hr⋅m2). The packing inscrubbers shall be of materials resistant to the effects of chlorine water.

Irrigation of scrubbers shall be with a neutralizing solution, an aqueous solution—3% soda and 2%sodium hyposulfite.

6.157. Electrolytic preparation of sodium hypochlorite shall be provided from a solution ofcommon salt or natural mineralized water containing no less than 50 g/L chlorides at water treatment plantswith a chlorine consumption of up to 50 kg/day.

6.158. Salt shall be stored in accordance with Paragraphs 6.203 and 6.213.The number of dissolving tanks to produce the saturated common salt solution shall be no less than

two, with total capacity of the tanks supporting a reserve of salt solution sufficient for at least 24 hours ofoperation of one electrolyzer.

6.159. Electrolyzers shall be located in a dry, heated room. They may be installed in the same roomwith other electrolysis equipment. The number of electrolyzers shall be no more than three, including onereserve.

Electrolyzers shall be placed to allow gravity flow of hypochlorite into an accumulating tank.6.160. The capacity of the hypochlorite accumulating tank shall support continuous operation of

one electrolyzer for at least 12 hours. The accumulating tank shall be located in a ventilated room. Feedingof water and drainage of wastewater shall be provided for washing and emptying of the tank.

6.161. Service tanks (no less than two) with a total capacity allowing for a solution concentrationof 1% and two batches per day shall be provided for preparation of powdered calcium hypochloritesolution.

The tanks shall be equipped with agitators.The solution shall be allowed to settle before hypochlorite dosing.Periodic removal of sediment from tanks and dosing units shall be provided.6.162. Tanks and pipes for solutions of salt and hypochlorite shall be made of corrosion-resistant

materials or have anticorrosion coatings.6.163. The contamination (disinfection) of water by direct electrolysis shall be used with a chloride

content of at least 20 mg/L and hardness not over 7 mg-eq/L at plants with capacities of up to 5 thousandm3/day.

6.164. Installations for decontamination of water by direct electrolysis shall be located in a roomadjacent to the pipes feeding water into filtered water storage tanks. One reserve installation shall beprovided.

6.165. When water is treated by chlorination and it is necessary to prevent a chlorophenol odor atthe treatment plant, devices shall be provided to feed gaseous ammonia into the water (ammoniation unit).

When justified, it is permissible to use ammonia also to increase the duration of the bactericidaleffect, for example upon long-term storage or transportation of water.

6.166. Ammonia shall be stored in cylinders or containers. Ammonia equipment shall be providedin explosion-safe form.

The ammonia section shall be organized in a manner similar to that of the chlorine section andlocated in separate rooms. It is permissible to combine the ammoniation unit with the chlorine sectionbuildings.

Ammonia dosing units shall be designed in accordance with Paragraphs 6.151 and 6.152.Ammonia shall be added to filtered water, and when phenols are present it shall be added 2-3 min

before the addition of chlorine-containing reagents.6.167. The time of contact of chlorine or hypochlorite with water from the moment of mixing until

the water reaches the nearest consumer shall be taken in accordance with GOST 2874-82.

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Contact of chlorine-containing reagents with water shall be organized in pure water tanks orspecial contact tanks. If water is not immediately distributed for use (along water trunk line), the contacttime in water lines may be considered.

6.168. Treatment of water with bactericidal radiation shall be performed for ground water withconstant satisfaction of the requirements of GOST 2874-82 in terms of physical-chemical characteristics.

The coli-index of treated water shall be not over 1000 units/L, the iron content—not over 0.3mg/L.

6.169. The number of operating bactericidal units shall be determined on the basis of their certifiedcapacity. The number of operating units shall be no more than five, reserve units—one.

6.170. Bactericidal units shall generally be located immediately before the point where the water isfed into the network to consumers on the delivery or intake pipes of pumps.

6.171. The use of ozone to treat water is permitted when justified. When designing ozonator units,devices shall be provided to synthesize ozone and mix the ozone-air mixture with the water. The necessaryozone dose for decontamination (disinfection) shall be taken as: for water from underground sources—0.75-1 mg/L, for filtered water—1-3 mg/L.

ELIMINATION OF ORGANIC SUBSTANCES, TASTES AND ODORS

6.172. When special treatment of water is required to eliminate organic substances and to reducethe intensity of taste and odor, oxidation and subsequent sorption of substances shall be performed byfiltering the water through granulated active carbon which is periodically regenerated or replaced.

In cases of short-term use of activated carbon and when justified, it may be used in powder form,introduced to the water before coagulation treatment or filtering.Notes: 1. When easily oxidized organic substances are present in the water in small concentrations, by agreementwith sanitary-epidemiological service agencies it may be permissible to use oxidation alone without sorptiontreatment if the oxidation does not form products which are unsatisfactory from the standpoint of taste and odor orharmful in the toxicologic respect.2. The rules for adding and doses of reagents, as well as the design parameters of oxidation units, shall be takenas defined in recommended Appendix 4.

STABILIZATION TREATMENT OF WATER AND TREATMENT WITH INHIBITORS TOELIMINATE CORROSION OF STEEL AND CAST IRON PIPE

6.173. The instructions of this Paragraph relate to the treatment of domestic-potable and processwater, not used to cool process equipment.Notes: 1. Methods for treating water for heat and hot water supply systems to prevent corrosion and overgrowthare not covered in this Paragraph.2. Treatment of recycled cooling water shall be performed in accordance with Section 11.

6.174. To protect water pipes and equipment from corrosion and the formation of deposits,stabilization treatment of water shall be performed, the need for which is established by estimating thestability of the water.

Water stability estimation shall be performed on the basis of technological analysis by the“carbonate test” method. If process stability test data are not available to estimate the water quality, it maybe determined by the methods presented in recommended Appendix 5.

6.175. Methods of stabilization treatment of water and design parameters shall be taken inaccordance with recommended Appendix 5.

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DEFERRIZATION OF WATER

6.176. The method of deferrization of water, calculated parameters and reagent doses shall bedetermined on the basis of the results of process studies performed directly at the water source.

6.177. Deferrization of ground water shall be performed by filtration in combination with one ofthe following methods of preliminary water treatment: simplified aeration, aeration on special devices,introduction of oxidizer reagents.Note: When justified, other methods may be used.

6.178. Simplified aeration shall be used with the following water quality characteristics:iron content (total) up to 10 mg/L;including bivalent iron (Fe2+) no less than 70%;pH at least 6.8;alkalinity over (1+Fe2+/28) mg-eq/L;content of hydrogen sulfide not over 2 mg/L.

6.179. Simplified aeration shall be performed with an excess of water in the pocket or centralchannel of open filters (discharge 0.5-0.6 m above water level). When pressure filters are used, air shall beintroduced into the feed pipe (air flow rate 2 L per g of ferrous oxide).

With a content of free carbonic acid in the water of over 40 mg/L and hydrogen sulfide over 0.5mg/L, an intermediate container into which the water flows freely without air entering the pipe shall beinserted before the pressure filters.

6.180. Aeration on special devices (aerators) or introduction of oxidizing reagents shall be usedwhen it is necessary to increase the amount of iron removed and the pH of the water.

The design and calculated parameters of aerators shall be taken similar to those of degassing unitsin accordance with recommended Appendix 7.

6.181. The calculated doses of oxidizing reagents shall be as follows:chlorine Dc, mg/L:

Dc = 0.7(Fe2+); (28)potassium permanganate Dp, mg/L, as KMnO4:

Dp = (Fe2+) (29)Oxidizing reagents shall be added to the feed pipe before the filters.6.182. The design of filters for deferrization of ground water shall be similar to that of filters for

clarification of water; the characteristics of the filtering layer and the speed of filtration with simplifiedaeration shall be as given in Table 29, when aerators are used or oxidizing reagents are added—as in Table24.

Table 29Characteristics of filtering layers for deferrization of water by simplified aeration Design

filtrationMinimum

graindiameter, mm

Maximumgrain

diameter, mm

Equivalentgrain

diameter, mm

Nonuniformityfactor

Layer height,mm

speed, m/hr

0.8 1.8 0.9-1.0 1.5-2 1000 5-71 2 1.2-1.3 1.5-2 1200 7-10

Notes: 1. When the water contains hydrogen sulfide, the lower values of filtration speed shall be used.2. The number of filters shall be no less than two.3. For plants with throughput up to 100 m3/day with pressure filters, one filter may be used if justified.

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6.183. Deferrization of the water from surface sources shall be performed simultaneously withclarification and decoloration (Paragraphs 6.2-6.117). The lime dose Dl, mg/L, as CaO, shall be determinedby the equation

Dl = 28(CO2/22 + Fe2+/28 + Dc/ec), (30)where CO2 is the content of free carbon dioxide in the incoming water, mg/L;Fe2+ is the content of bivalent iron in the incoming water, mg/L;Dc is the dose of coagulant (as the anhydrous substance), mg/L;ec is the equivalent mass of (anhydrous) coagulant, mg/mg-eq.

6.184. A circulating system for wash water and sediment treatment devices for deferrization plantsshall be used in accordance with Paragraphs 6.195-6.200.

FLUORINATION OF WATER

6.185. The need for fluorination of drinking water shall be determined in each individual case bythe sanitary-epidemiologic service agencies.

The design of fluorination units shall be performed in accordance with recommended Appendix 6.

REMOVAL OF MANGANESE, FLUORINE AND HYDROGEN SULFIDE FROM WATER

6.186. The selection of methods of water treatment, design of parameters of facilities, as well asthe type and dose of reagents shall be based on process studies performed directly at the water source (forwater containing excess quantities of manganese and hydrogen sulfide).

6.187. Manganese removal shall be performed by a non-reagent method or with the use ofreagents.

If non-reagent methods cannot achieve the required degree of removal, water shall be treated withoxidizing reagents (potassium permanganate, ozone, etc.) with the introduction of a flocculant andsubsequent filtration.

Where ground water is used in which manganese is present together with iron, the possibility shallbe checked of its removal in the process of deferrization without additional reagent use.

6.188. Defluorination of water shall be performed by contact-sorption coagulation or with the useof a sorbant—active aluminum oxide.

The method of contact-sorption coagulation shall be used with a concentration of fluorine in thewater of up to 5 mg/L; with a sorbant (active aluminum oxide) where the concentration of fluorine is up to10 mg/L.

When justified, other methods may be used.6.189. Water shall be cleansed of hydrogen sulfide by aeration and chemical methods. The aeration

method may be used with a hydrogen sulfide content in the water of up to 3 mg/L, the chemical method upto 10 mg/L.

When justified, other methods may be used.

SOFTENING OF WATER

6.190. The following methods shall be used to soften water: to remove carbonate hardness—decarbonization with lime or hydrogen-cation softening with “starvation” regeneration of the cationites;to eliminate carbonate and noncarbonate hardness—lime-soda, sodium-cationite or hydrogen-sodium-cationite softening.

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6.191. When softening ground water, cationite methods shall be used; when softening surfacewater, when it is simultaneously necessary to clarify the water, the lime or lime-soda method shall be used,while when deep softening of the water is required—subsequent cation treatment.

When softening water for drinking, reagent methods shall be used (lime or lime-soda method) plusthe method of partial Na cation treatment.

Reagent softening of ground water shall be used considering the liquidation of wastewater andsediments formed in softening units.

6.192. The methods of softening and design parameters of units shall be applied in accordance withrecommended Appendix 7.

FRESHENING AND DESALINATION OF WATER

6.193. Preliminary selection of a method of freshening and desalination of water may be performedusing the data of Table 30.

Table 30Methods of freshening and

desalinationSalt content of water, mg/L

input freshened and desalinatedIon exchange 1500-2000 0.1-20Distillation Over 10,000 0.5-50Electrodialysis 1500-15,000 At least 500Reverse osmosis (hyperfiltration) Up to 40,000 10-1000

6.194. The data and calculated parameters for the design of water freshening and desalination unitsemploying ion exchange and electrodialysis shall be taken in accordance with the instructions presented inrecommended Appendix 8.

TREATMENT OF WASH WATER AND SEDIMENT FROM WATER TREATMENT PLANTS

6.195. The requirements of this Section extend to clarification, deferrization and reagent softeningfacilities for natural waters.

6.196. At clarification and deferrization plants employing filtration the wash water of filterfacilities shall be settled. The clarified water shall be regularly transferred into the pipes upstream frommixers or into mixers. It is permissible to use clarified water to wash contact clarifiers considering therequirements of Paragraph 6.132.

At plants which clarify water by settling with subsequent filtration and at reagent softening plants,wash water shall be uniformly transferred into the pipes upstream from mixers or into the mixers, with orwithout settling depending on water quality.

6.197. Sand traps shall be provided to trap sand carried away during washing of filters or contactclarifiers.

6.198. The sediment from all settling facilities and the reagent section shall be dewatered andstored with or without preliminary thickening.

Clarified water liberated in the process of thickening and dewatering of sediment shall be directedinto pipes upstream from mixers or into mixers, and also may be discharged into streams or bodies of waterconsidering the instructions of Paragraph 6.4 or into sewage treatment facilities.

When preliminary chlorination of input water is not used, circulating water shall be chlorinatedwith a dose of 2 to 4 mg/L.

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6.199. In wash water and sediment processing systems, the following main facilities shall beprovided: storage tanks, settling tanks, thickeners, accumulators or areas for freezing and drying ofsediment.

When justified, it is permissible to use mechanical dewatering and regeneration of coagulant fromsediment.

6.200. The usage conditions and design parameters of facilities for treating wash water andsediment shall be taken in accordance with recommended Appendix 9.

Table 31Area, m2, of laboratory and supplementary rooms with plant

throughput, m3/dayRooms Less than

30003000-10,000

10,000-50,000

50,000-100,000

100,000-300,000

1. Chemical laboratory 30 30 40 40 2 rooms 40and 20

2. Weighing — — 6 6 83. Bacteriological laboratoryautoclave room

20 20 20 30 2 rooms 20and 20

10 10 10 15 154. Medium preparation andwashing

10 10 10 15 15

5. Room for hydrobiologicalstudies (for water sourcesrich in microflora)

— — 8 12 15

6. Room for storage ofglassware and reagents

10 10 10 15 20

7. Office of laboratory chief — — 8 10 128. Local control point Designated based on scheduling and automation plan9. Room for duty person 8 10 15 20 2510. Testing laboratory — 10 10 15 1511. Office of plant chief 6 6 15 15 2512. Shop for repair of smallequipment and instruments

10 10 15 20 25

13. Locker room, showersand restroom

Per SNiP 2.09.04-87

Notes: 1. Areas of laboratory and supplementary rooms may be changed by up to 15% of values given in tabledepending on building design.2. With centralized water quality monitoring, the composition of laboratories and supplementary rooms may bereduced by agreement with sanitary epidemiological service agencies.3. When ground water is fed to consumers without preparation with chlorine decontamination (disinfection), only aroom with an area of 6 m2 shall be provided for analysis of residual chlorine content.3. For plants with throughput over 300,000 m3/day, composition of rooms shall be established in each case

depending on local conditions.

SUPPLEMENTARY ROOMS OF WATER TREATMENT PLANTS

6.201. The buildings of water treatment plants shall include laboratories, shops, housekeeping andother supplementary rooms.

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The composition and areas of rooms shall be determined depending on the purpose and throughputof the plant, as well as the water supply sources.

For plants preparing drinking water from surface sources the composition and area of rooms shallbe as given in Table 31.

REAGENT AND FILTERING MATERIALS STORAGE

6.202. Storage areas for reagents shall be designed to store a 30-day supply, calculated based onthe period of maximum reagent consumption, but no less than the volume of a single delivery.Notes: 1. When justified, the capacity of a storage area may be sufficient for some other storage term, but no lessthan 15 days.When central (base) storage facilities are available, the storage area of a water treatment plant may be calculatedfor a storage time of no less than 7 days.2. The conditions of reception of the amount of a single delivery do not extend to chlorine storage facilities.3. The requirements of this Section do not extend to the design of base storage facilities.

6.203. Depending on the type of reagent, a storage facility shall be designed for dry or wet storagein the form of a concentrated solution. If the volume of a single delivery, exceeding 30 days consumption ofreagents, is stored in wet form, it is permissible to construct an additional storage facility for dry storage ofa portion of the reagents.

6.204. Dry storage of reagents shall be in closed storage facilities.When determining the area of a storage facility for coagulant the height of a layer shall be taken as

2 m, for lime 1.5 m; with mechanized unloading the layer height may be increased: coagulant to 3.5 m; limeto 2.5 m.Reagents packaged by the supplier shall be stored in the supplied packages.

Opening of packages containing iron chloride and sodium silicate, freezing and storage ofpolyacrylamide for more than 6 months shall not be permitted.

6.205. With wet storage of coagulant in dissolving tanks in which concentration solutions (15-20%) are made, depending on the design of the tanks and the strength of the reagent solution, the volume ofthe tanks shall be determined by calculation at 2.2-2.5 m3 per ton of commercial unpurified coagulant and1.9-2.2 m3 per ton of purified coagulant.

The total capacity of dissolving tanks shall be related to the volume of a single reagent delivery.The number of dissolving tanks shall be no less than three.

6.206. With a monthly consumption of coagulant greater than the volume of a single delivery, aportion of the reagent shall be stored in storage tanks of concentrated reagent solution, the volume of whichshall be determined by calculation at 1.5-1.7 m3 per ton of commercial coagulant.

It is permitted to place dissolving tanks and storage tanks out of doors. When this is done, thecondition of the tank walls shall be monitored and steps taken to prevent the penetration of the solution intothe soil.

The number of storage tanks shall be no less than three.6.207. When lump lime is used, it shall be slaked and stored in containers as a paste of 35-40%

concentration. The volume of the tanks shall be determined by calculation at 3.5-5 m3 per ton ofcommercial lime. Tanks for slaking shall be located in an isolated room.

Dry storage of lime with subsequent crushing and slaking in lime slaking equipment is permitted.When centralized delivery of lime paste or milk is possible, wet storage shall be arranged.6.208. An activated carbon storage facility shall be placed in a separate room. There are no

explosion safety requirements for this storage facility, but its fire safety shall be of category B.6.209. Rooms for storage of cationite and anionite shall be designed for the volume of the charge of

two cationite filters, one anionite filter with weak basic and one with strong basic anionite, if used.

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6.210. Storage facilities for reagents (except for chlorine and ammonia) shall be located nearrooms for the preparation of their solutions and suspensions.

6.211. The capacity of the chlorine service storage facility shall not exceed 100 tons, that of eachcompletely isolated section—50 tons. A storage facility or section shall have two exits on opposite sides ofthe building or room.

Storage facilities shall be located in ground level or semi-underground buildings (with twostairwells).

Storage of chlorine shall be in cylinders or containers; with a daily consumption of chlorine of over1 ton, factory-manufactured tanks with a capacity of up to 50 metric ton may be used, but transfer ofchlorine into cylinders or containers at the plant is not permitted.

The storage facility shall have devices for transportation of reagents in nonstationary packages(containers, cylinders).

Motor vehicles shall not be permitted to enter the storage facility. Empty containers shall be storedin a room at the storage facility.

Vessels containing chlorine shall be located on supports or in frames, with free access for strappingand ceasing for transportation.

6.212. The chlorine storage facility shall have a tank of neutralizing solution for rapid immersionof leaking containers or cylinders. The distance from the walls of this tank to a cylinder shall be no lessthan 200 mm, to a container—no less than 500 mm, the depth shall be sufficient to cover a faulty vesselwith a layer of solution of no less than 300 mm.

Supports to fix vessels shall be provided on the floor of the tank.Scales for weighing of a container or cylinder shall be provided with supports to fix them in place.

Note: These standards do not extend to the design of service chlorine facilities using tanks.6.213. Wet storage facilities shall be used for common salt. The volume of tanks shall be

determined by calculation at 1.5 m3 per metric ton of salt. It is permissible to use dry storage tanks, with asalt layer height of not over 2 m.

6.214. In cases when plants are not supplied with standardized filtering materials and gravel, aspecial section shall be set up for storage, crushing, sorting, washing and transportation of materialsnecessary for additional charging of filters.

6.215. The design of containers for the storage of filtering materials and selection of equipmentshall be performed by calculation at 10% annual supplement and exchange of filter charge and anemergency reserve for recharging one filter when there are up to 20 at the plant, or two with a largernumber of filters.

6.216. Transportation of filtering materials shall be by hydraulic transport (water jet or sandpump).

The diameter of pipes for transportation of slurries shall be determined by calculating the speed ofmovement of the slurry as 1.5-2 m/s, but shall be no less than 50 mm; bends in pipes shall have a radius ofno less than 8-10 pipe diameters.

6.217. Unloading operations and transportation of reagents at storage facilities and within plantsshall be mechanized.

HEIGHT OF PLACEMENT OF FACILITIES AT WATER TREATMENT PLANTS

6.218. Facilities shall be placed on the natural slope of the terrain considering head losses infacilities, connecting lines and measurement devices.

6.219. The drop in water level in facilities and connecting lines shall be determined by calculation;the head loss may be accepted as follows for preliminary height placement of facilities, m:

in facilitieson drum screen filters (drum screens and microfilters) 0.4-0.6

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in intake (contact) chambers 0.3-0.5in reagent intake devices 0.1-0.3in hydraulic mixers 0.5-0.6in mechanical mixers 0.1-0.2in hydraulic flocculation chambers 0.4-0.5in mechanical flocculation chambers 0.1-0.2in settling tanks 0.7-0.8in clarifiers with suspended sediment 0.7-0.8on rapid filters 3-3.5in contact clarifiers and prefilters 2-2.5in slow filters 1.5-2

in connecting linesfrom drum screen filters or intake chambers to mixers 0.2from mixers to settling tanks, clarifiers with suspended sediment and contact clarifiers 0.3-0.4from settling tanks, clarifiers with suspended sediment or prefilters to filters 0.5-0.6from filters or contact clarifiers to filtered water storage tanks 0.5-1Notes: 1. The values presented consider head losses in collecting, feeding and distributing devices of facilities.2. The head losses in measurement apparatus shall be considered additionally by calculation as:at the output and input of the plant—0.5 m each;in flow indicators in settling tanks, clarifiers with suspended sediment, filters and contact clarifiers—0.2-0.3 meach.3. When determining the water level difference between facilities and the head loss in connection lines bycalculation, the calculated water flow rates shall be determined considering instructions of Section 6.8.

6.220. Water treatment plants shall provide a system of bypass lines allowing disconnection ofindividual facilities, as well as feeding of water in emergencies to bypass a facility.

With a plant throughput of over 100,000 m3/day, bypass lines may be omitted.Note: Valve equipment on bypass lines shall be sealed.

7. PUMPING PLANTS

7.1. Pumping plants shall be classified as to their dependability into three categories in accordancewith Paragraph 4.4.

The category of pumping plants shall be determined in accordance with their functional purpose inthe overall water supply system.Notes: 1. Pumping plants supplying water directly into a fire suppression network and combined fire suppressionwater line shall be placed in category I.2. Pumping plants used for fire suppression and combined fire suppression lines at objects listed in note 1 ofParagraph 2.11 could be placed in category II.3. Pumping plants feeding water into a single pipe, as well as for irrigation, shall be placed in category III.4. For an established pumping plant category, the same category of electric power supply reliability shall beselected in accordance with the Regulations on Devices of Electrical Installations (PUE) of the USSR Ministry ofPower Engineering.

7.2. The selection of the type of pumps and number of operating units shall be based on calculationof the joint operation of pumps, water lines, networks, regulating vessels, the hourly and daily graphs ofwater consumption, conditions of fire suppression, and the sequence in which the object is put on stream.

When selecting the type of pumping devices, the minimum excess head developed by the pumps inall operating modes shall be assured by the use of regulating vessels, adjustment of pump speeds, changesin the number and types of pumps, trimming or replacement of impellers in accordance with changes intheir operating conditions during the course of the design period.Notes: 1. Groups of pumps of various types may be installed together in machine rooms.

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2. In pumping plants supplying drinking water the installation of pumps transferring strong-smelling or poisonousliquids is forbidden, with the exception of pumps supplying foaming agents to a fire suppression system.

7.3. In pumping plants for a group of pumps supplying water for the same network or water linesthe number of reserve units shall be taken as in Table 32.

7.4. The level of a pump shaft shall be determined generally in order to set the pump body forpriming:

in a vessel—from the maximum level of water (measured from the bottom) for fire suppressionwith a single fire, the average level—for two or more fires; from the emergency water level if there is nofire volume; from the average water level if there is neither a fire nor an emergency volume;

in a water intake well—from the dynamic level of ground water with maximum water intake;in a stream or body of water—from the minimum water level according to Table 11, depending on

the water intake category.

Table 32Number of operating

units of one groupNumber of reserve units in pumping

plants of categoriesI II III

Up to 6 2 1 1From 6 to 9 2 1 —Over 9 2 2 —

Notes: 1. The number of operating units includes fire pumps.2. The number of operating units in one group shall be no less than two. In pumping plants of categories II and III,when justified, a single operating unit may be installed.3. When pumps with different characteristics are installed in one group, the number of reserve units shall be takenfor pumps of high output from Table 32; a reserve pump of lower output shall be held in storage.4. In pumping plants serving combined high pressure fire suppression lines or when only fire pumps are installed,one reserve fire unit shall be maintained regardless of the number of operating units.5. In pumping plants supplying water to population centers with up to 5000 residents with a single source ofelectric power, a reserve fire pump with internal combustion engine and automatic starting (from batteries) shallbe provided.6. In category II pumping plants with number of operating units 10 or more, one reserve unit may be held instorage.7. In order to increase the output of underground pumping plants by up to 20-30%, the possibility shall beprovided of replacing pumps with pumps of greater capacity or reserve foundations shall be provided for theinstallation of additional pumps.

When determining the level of a pump shaft, the permissible vacuumetric suction height (from thedesign minimum water level) or necessary intake side head specified by the manufacturer shall beconsidered, as well as head losses in the intake line, temperature conditions and barometric pressure.Notes: 1. In category II and III pumping plants it is permissible to install pumps at a level where they are notprimed, in which case vacuum pumps and a vacuum boiler are required.2. The level of the machine room floor in underground pumping plants shall be determined on the basis of theinstallation of higher capacity pumps or larger pumps considering note 7 of Paragraph 7.3.3. In category III pumping plants, receiving valves up to 200 mm in diameter may be installed on the intake pipe.

7.5. The number of intake lines to a pumping plant, regardless of the number and groups of pumpsinstalled, including fire pumps, shall be no less than two.When one line is disconnected, the remaining lines shall be designed to carry the full design load forcategory I and II pumping plants and 70% of the design load for category III plants.Category III pumping plants may be designed with a single intake line.

7.6. The number of discharge lines in category I and II pumping plants shall be no less than two.For category III pumping plants a single discharge line may be provided.

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7.7. The placement of valves on intake and delivery pipes shall allow replacement or repair of anypump, check valve or main valve, as well as checking of pump characteristics while satisfying therequirements of Paragraph 4.4 in terms of water supply.

7.8. The discharge line of each pump shall be equipped with cut-off valves and, as a rule, a checkvalve, installed between the pump and the cut-off valve.

If mounting inserts are installed they shall be placed between the cut-off valve and the check valve.On the intake lines of each pump the cut-off valve shall be installed next to primed pumps or

connected to a common intake collector.7.9. The diameter of pipes, the volute casing and valves shall be selected on the basis of technical

and economic calculation using water speeds within the limits given in Table 33.

Table 33Pipe diameter, mm Speeds of water in pumping plant pipes, m/s

intake dischargeUp to 250 0.6-1 0.8-2From 250 to 800 0.8-1.5 1-3Over 800 1.2-2 1.5-4

7.10. The dimensions of the machine room of a pumping plant shall be determined considering therequirements of Section 12.

7.11. To reduce the dimensions of a plant in plan it is permissible to install pumps with right andleft shaft rotation, with the impeller rotating only in one direction.

7.12. The intake and discharge collectors and cut-off valves shall be located in the pumping plantbuilding unless this requires an increase in the machine room span.

7.13. Pipes in pumping plants, as well as intake lines outside the machine room, shall generally bemade of steel welded pipe using flanges for connection to valves and pumps.

7.14. The intake pipe, as a rule, shall have a continuous rise toward the pump of at least 0.005. Atplaces where pipe diameters change, eccentric adapters shall be used.

7.15. In underground and semi-underground pumping plants, measures shall be taken to preventpossible flooding of equipment in case of an emergency in the machine room involving the highest capacitypump, as well as valves or pipes by: placement of the electric motors driving pumps at a height of at least0.5 m above the floor of the machine room; gravity discharge of the emergency quantity of water into asewer or onto the surface of the ground with setting of a valve; pumping of water from the well using mainpumps.

When it is necessary to install emergency pumps, their delivery shall be made sufficient to pumpwater from the machine room with a depth of 0.5 m in not over 2 hours and provide one reserve unit.

7.16. To allow water to run off the floors and channels, the machine room shall be designed with aslope toward the drainage well. Pump foundations shall have rims, channels and pipes for drainage ofwater. If gravity drainage of water from the well is impossible, drainage pumps shall be provided.

7.17. In underground pumping plants operating in automatic mode with the machine room 20 m ormore below the surface, and also in pumping plants with a depth of 15 m or more where personnel areconstantly present, a passenger elevator shall be provided.

7.18. Pumping plants with machine room size 6 × 9 m or more shall be equipped with an internalfire suppression water line with a water flow rate of 2.5 L/s.

The following are also required:when electric motors with a voltage of up to 1000 V or less are installed: two manual foam fire

extinguishers, with internal combustion engines of up to 300 hp—four fire extinguishers;

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with electric motors having a voltage of over 1000 V or an internal combustion engine with apower of over 300 hp, two additional carbon dioxide fire extinguishers, a 250 L water tank, two pieces offelt, asbestos fiber or felting measuring 2 × 2 m.Notes: 1. Fire suppression valves shall be connected to the delivery collector of the pumps.2. In pumping plants at water supply wells the fire suppression water line is not required.

7.19. In a pumping plant, regardless of the extent of its automation, a restroom (toilet and sink),and locker room for storage of the clothing of operating personnel (duty repair team) shall be provided.

If a pumping plant is located at a distance of not over 50 m from production buildings havingrestrooms, a restroom need not be provided.

In pumping plants over water supply wells, a restroom is not required.A septic system may be used at pumping plants located away from population centers or industrial

sites.7.20. A work bench shall be installed in an isolated pumping plant for the performance of minor

repairs.7.21. In pumping plants with internal combustion engines, service tanks of liquid fuel may be

installed (gasoline up to 250 L, diesel fuel up to 500 L) in rooms separated from the machine room byfireproof structures with fire resistance time rating at least 2 hours.

7.22. Monitoring and measurement equipment shall be installed in pumping plants in accordancewith the requirements of Section 13.

7.23. Fire suppression water supply pumping plants may be located in production buildings, inwhich case they shall be surrounded by fire walls.

8. WATER LINES, WATER NETWORKS AND THEIR FACILITIES

8.1. The number of water lines used shall be determined considering the category of a water supplysystem and the sequence of construction.

8.2. When water pipes are placed in two or more lines the need for switching between the waterlines is determined depending on the number of independent water supply facilities or water lines feedingwater to a consumer. In case of disconnection of one water line or portion of a line, the total supply ofdrinking water to the object may be reduced by no more than 30% of the design flow rate, the total amountof water for process needs—according to an emergency schedule.

8.3. When water pipes are laid in a single line and water is supplied from a single source, thevolume of water required for the time of repair of an emergency on the line shall be determined inaccordance with Paragraph 9.6. If water is supplied by several sources, the emergency water reserve maybe reduced if the requirements of Paragraph 8.2 are met.

8.4. The design emergency repair time of the pipes of a category I water supply system shall betaken from Table 34. For category II and III water supply systems the time given in the table shall beincreased by 1.25 and 1.5 times.

Table 34Pipe diameter, mm Design time to repair an emergency on a pipe,

hr, with pipe depth in the ground, mup to 2 over 2

up to 400 8 12From 400 to 1000 12 18Over 1000 18 24

Notes: 1. Depending on the pipe material and diameter, specifics of the route of the water line, conditions of pipelaying, presence of roads, transportation equipment and emergency repair devices, this time may be modified, butshall be taken as no less than 6 hours.

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2. It is permissible to increase the emergency repair time if the duration of water supply interruption and reducedwater supply will not exceed the limits indicated in Paragraph 4.4.3. When it is necessary to disinfect pipes after repairs, the time given in the table shall be increased by 12 hours.

8.5. Water supply networks shall be of ring type. Dead-end water supply lines may be used:to feed water for process purposes—when it is permissible to interrupt the water supply for the

duration of a repair;to feed drinking water—with pipe diameter not over 100 mm;to feed fire suppression or process and fire suppression water, regardless of the fire suppression

water flow—with a line length of not over 200 m.Looping of external water supply networks by the use of internal water supply networks of

buildings and facilities is not permitted.Note: In population centers with up to 5000 residents and a water consumption for external fire suppression of upto 10 L/s with the number of internal fire suppression valves in a building up to 12, dead-end lines of over 200 mlength are permitted if fire-suppression storage tanks or pools, water towers or counter-reservoirs are provided atthe end of the dead-end section.

8.6. When one section (between design nodes) is disconnected, the total supply of drinking waterusing the remaining lines shall be no less than 70% of the design flow, and the supply of water to the mostunfavorably located points shall be no less than 25% of the design water flow, with a free head of no lessthan 10 m.

8.7. Construction of secondary lines for attachment of consumers is permitted with a main waterline diameter of 800 mm or more and a transit flow rate of no less than 80% of the total flow; for smallerdiameters they are permitted when justified.

With a passage width of over 20 m it is permitted to lay duplicate lines, without allowing crossingof passages by intakes.

In these cases, fire hydrants shall be installed on the secondary or duplicate lines.With a street width between red lines of 60 m or more, the possibility of laying water lines on both

sides of the street shall be considered.8.8. Connection of drinking water supply networks to networks of water lines supplying water of

nondrinking quality is not permitted.Note: In exceptional cases, by agreement with agencies of the sanitary-epidemiological service, it may bepermissible to use a drinking water line as a reserve for a water line supplying water of nondrinking quality. Thedesign of the interconnection in such cases shall provide an air gap between the networks and prevent thepossibility of reverse flow of water.

8.9. On the water pipes and lines of a water supply network, in necessary cases the following shallbe installed:

rotating valves (gate valves) to isolate repair segments;valves for inlet and outlet of air during emptying and filling of pipes;valves for inlet and trapping of air;air escape valves for releasing air in the process of pipe operation;taps for discharge of water during emptying of pipes;compensators;mounting inserts;check valves or other types of automatic valves for disconnection of repair segments;pressure regulators;equipment to prevent increases in pressure with water hammer or defects in pressure regulators.On pipes 800 mm and more in diameter it is permissible to install manholes (for inspection and

cleaning of pipes, repair of control valves, etc.).Relief chambers or equipment preventing the pressure from rising above the limit permissible for

the type of pipe used in all possible operating modes shall be installed on gravity-pressurized water lines.

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Note: The use of gate valves in place of rotary valves is permitted where systematic cleaning of the internalsurface of pipes using special equipment is required.

8.10. The length of repair sections of water lines shall be: where water pipes are laid in two ormore lines with no interconnections—not over 5 km; where there are interconnections—equal to the lengthof the sections between interconnections, but not over 5 km; where water pipes are laid in one line—notover 3 km.Note: The division of a water supply network into repair sections shall assure, with one of the sectionsdisconnected, disconnection of not over 5 fire hydrants and supply of water to the consumers that need watersupply without interruption.With justification the length of repair sections may be increased.

8.11. Automatically operated valves for inlet and outlet of air shall be provided at the high pointson a profile and at the highest end points of repair sections of water lines and networks to prevent theformation of a vacuum in a pipe greater than that permissible for the type of pipe used, and also to removeair from the pipe as it is filled.

With a vacuum not exceeding the permissible vacuum, manually operated valves may be used.It is permissible to use automatic valves for air inlet and trapping with valves (rotary or gate) with

manual operation of air escape valves in place of automatic valves for inlet and outlet of air, depending onthe flow rate of the air to be released.

8.12. Air escape valves shall be provided at the highest points on profiles on air collectors. Thediameter of the air collector shall be equal to the diameter of the pipe, its height—200-500 mm dependingon the pipe diameter.

When justified it is permissible to use air collectors of other sizes.The diameter of the valve equipment disconnecting an air escape valve from an air collector shall

be equal to the diameter of the connecting piece of the air escape valve.The required throughput capacity of an air escape valve shall be determined by calculation or taken

as 4% of the maximum design flow rate of water fed through the pipe, using the volume of air at normalatmospheric pressure.If a water line has several high points on its profile, at the second and subsequent points (in the direction ofwater movement) the required throughput capacity of the air escape valve may be 1% of the maximumdesign water flow, if the high point is located lower than the first high point or no more than 20 m higherthan it and at a distance from the previous high point of no more than 1 km.Note: With a slope of a descending segment of a pipe (after a high point on its profile) of 0.005 or less, air escapevalves shall not be required; with a slope of 0.005-0.01, instead of the air escape valve, a cock (valve) may beinstalled at the high point of the profile.

8.13. Water lines and water supply networks shall be designed with a slope of at least 0.001 in thedirection of an outlet; where the terrain relief is flat, the slope may be reduced to 0.0005.

8.14. Outlets shall be provided at low points in each repair section, as well as at points wherewater is released after washing of pipes.

The diameters of outlets and air inlet devices shall support emptying of water line sections ornetworks in no more than 2 hours.

The design of outlets for pipe washing shall be such as to permit a speed of movement of water inthe pipe of no less than 1.1 times the maximum design speed.

Rotary valves shall be used at outlets.Note: During hydropneumatic washing the minimum speed of mixture movement (at points of maximum pressure)shall be no higher than 1.2 times the maximum speed of movement of water, the flow rate of water—10-25% of thevolumetric flow rate of the mixture.

8.15. Drainage of water from outlets shall be provided into the nearest water drain, canal, gully,etc. If it is impossible to drain all of the water released or a portion of it by gravity, water may be dumpedinto a well and subsequently pumped out.

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8.16. Fire hydrants shall be provided along roads at a distance of not over 2.5 m from the edge ofthe roadway, but no closer than 5 m from the walls of buildings; hydrants may be located on the roadway.Installation of hydrants on a branch off of the water line is not permitted.

The location of hydrants on the water supply network shall support fire fighting in any building,structure or part of a building or structure served by the network by no less than two hydrants if a waterflow rate for outdoor fire fighting of 15 L/s or more and no less than one fire hydrant if a water flow rate ofless than 15 L/s considering laying of hoses no longer than those indicated in Paragraph 9.30 on pavedroads.

The distance between hydrants is determined by calculation, considering the total flow rate ofwater for fire fighting and the throughput capacity of the type of hydrant installed according to GOST8220-85*E.

The head loss h, m, per m of hose length shall be determined by the equation

,0038.0 2fqh = (31)

where qf is the throughput of the fire fighting stream, L/s.Note: For water supply networks of population centers with up to 500 residents, hydrants may be replaced bystandpipes 80 mm in diameter with fire valves.

8.17. Compensators shall be provided:on pipes, the butt joints of which do not compensate for axial displacements caused by changes in thetemperature of the water, air or soil;on steel pipes laid in tunnels, channels or on trestles (supports);on pipes under conditions of possible soil settlement.

The distance between compensators and nonmoving supports shall be determined by calculation,considering their design. With underground laying of water lines, main and network lines of steel pipe withwelded joints, compensators shall be provided at points of installation of cast iron flange equipment. Inthose cases when the cast iron flange equipment is protected from axial tensile forces by rigid attachment ofsteel pipes to manhole walls, by special supports or compression of pipes in compacted soil, compensatorsneed not be provided.

When a pipe is compressed in soil before a cast iron flange, movable butt joints shall be provided(elongated mouth, union, etc.). Compensators and movable butt joints shall be placed in manholes wherepipes are laid underground.

8.18. Mounting inserts shall be used for removal, preventive inspection and repair of flange stop,safety and control equipment.

8.19. Valves on water lines and water supply networks shall be manually or mechanically driven(by mobile equipment).

Use on water lines of valves with electrical or hydraulic drive is permitted where remote orautomatic control is used.

8.20. The operating radius of a standpipe shall be not over 100 m. A clear area shall be providedaround a standpipe with a width of 1 m and a slope of 0.1 away from the standpipe.

8.21. The selection of the material and strength class of pipe for water lines and water supplynetworks shall be based on static calculations, the corrosiveness of the soil and the water transported, aswell as the operating conditions of pipes and requirements for water quality.

For pressure pipes and networks, as a rule, nonmetallic pipe shall be used (reinforced concrete,asbestos cement, plastic, etc.). Refusal to use nonmetallic pipe shall be justified.

The use of cast iron pressure pipe is permitted for networks within population centers, theterritories of industrial and agricultural enterprises.

The use of steel pipe is permitted:in sections with design internal pressure over 1.5 MPa (15 kgf/cm2);for crossings beneath railroads and highways, over water barriers and gullies;

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at points of intersection of drinking water lines with sewer networks;when pipe is placed with highway and city bridges, on trestles and in tunnels.Steel pipe shall be selected of economical grades with wall thickness determined by calculation (but

no less than 2 mm) considering the operating conditions of the pipe.Metal sections may be used with reinforced concrete and asbestos cement pipe where complex

contours are required.The material of pipes used with drinking water systems shall satisfy the requirements of Paragraph

1.3.8.22. The design internal pressure shall be taken equal to the maximum possible pressure based on

the operating conditions in pipes over various length sections (under the most unfavorable operatingconditions), without considering the increase in pressure resulting from water hammer or the increase inpressure during water hammer considering the effects of anti-hammer equipment if this pressure incombination with other loads (Paragraph 8.26) will have greater effect on the pipe.

Static calculation shall be performed for the effect of the design internal pressure, soil pressure,temporary loads, the mass of the pipe itself and the mass of the liquid transported, atmospheric pressure incase of formation of vacuum and external hydrostatic pressure of ground water in those combinationswhich are most dangerous for pipe of the material used.

Pipes or their sections shall be classified in terms of degree of importance into the followingclasses:

1—pipe for water supply category I reliability customers, as well as sections of pipes in areas ofcrossings over water barriers and gullies, category I and II railroads and highways and in places difficult toreach in order to repair possible damage, for objects of category II and III water supply reliability;

2—pipes for water supply category II reliability customers (with the exception of class I sections),as well as sections of pipes laid beneath paved roads, for objects of water supply reliability category III;

3—all other pipe sections for water supply category III reliability customers.Calculations shall be performed considering the operating conditions factor mc, determined by the

equationmc = m1m2/γr, (32)

where m1 is a coefficient considering the length of testing of pipe after its manufacture; m2 is a coefficientconsidering the loss of strength of the pipe in the process of use as a result of aging of pipe materials,corrosion or abrasive wear; γr is the reliability factor, considering the class of the section of pipe in terms ofits importance.

The value of coefficient m1 shall be established in accordance with the GOST or specifications formanufacture of the given type of pipe.

For pipes, butt joints in which are as strong as the pipe itself, the value of coefficient m1 shall betaken as:

0.9—for cast iron, steel, asbestos-cement, concrete, reinforced concrete and ceramic pipe;1—for polyethylene pipe.The value of coefficient m2 shall be taken as:1—for ceramic pipe, as well as cast iron, steel, asbestos cement, concrete and reinforced concrete

pipe if there is no danger of corrosion or abrasive wear in accordance with the GOST or specifications formanufacture of the given type of pipe—for plastic pipe.

The value of coefficient γr shall be taken for class 1 pipe sections as 1; for class 2—0.95; for class3—0.9.

8.23. The test pressure to be used in various test sections before they are put in operation shall beindicated in the plans of the construction organization, based on the strength characteristics of the materialand class of pipe used in each pipe section, the design internal water pressure and external loads acting onthe pipe during the test period.

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The design test pressure shall not exceed the following values for pipes made of:cast iron—the factory test pressure with a factor of 0.5;reinforced concrete and asbestos cement—the hydrostatic pressure provided in the GOST or specificationsfor the class of pipe with no external load;steel and plastic—the design internal pressure with a factor of 1.25.

8.24. Cast iron, asbestos cement, concrete, reinforced concrete and ceramic pipe shall be designedfor the combined influence of the calculated internal pressure and adjusted external design load.

Steel and plastic pipe shall be designed for exposure to the internal pressure in accordance withParagraph 8.23 and the simultaneous effect of external adjusted load, atmospheric pressure, as well as thestability of the circular cross-sectional shape of the pipe.

The reduction in vertical diameter of steel pipe without internal protective coatings shall not exceed3%, and for steel pipe with internal protective coatings and plastic pipe shall be taken from the standards orspecifications for the pipe.

When determining the vacuum, the effect of anti-vacuum devices installed on the pipe shall beconsidered.

8.25. As temporary loads, the following shall be considered:for pipe laid beneath railroad tracks—the load corresponding to the class of the railroad line;for pipe laid beneath highways—from a column of N-30 vehicles or NK-80 wheeled transporters

(whichever yields the greater force effect on the pipe);for pipes laid in places where vehicles may travel—from a column of N-18 vehicles or NG-60

tracked transporters (whichever yields the greater force on the pipe);for pipes laid in places where vehicles cannot pass—a uniformly distributed load of 5kPa (500

kgf/m2).8.26. When designing pipes for the pressure increase of water hammer (determined considering

anti-hammer equipment or the formation of a vacuum) the external load shall be considered no greater thanthe load produced by a column of N-18 vehicles.

8.27. The increase in pressure during water hammer shall be determined by calculation andprotective measures taken on its basis.

The protective measures taken for a water supply system against water hammer shall be providedfor the following cases:

sudden shutdown of all or a group of jointly operating pumps due to an electric power failure;shutdown of one of a group of jointly operating pumps before the rotary valve (gate valve) on its

discharge line is closed;startup of a pump with open rotary valve (gate valve) on its discharge line, equipped with a check

valve;mechanized closure of a rotary valve (gate valve) upon disconnection of an entire water line or of

individual sections;opening or closing of high-speed water distributing valves.8.28. The protective measures against water hammer caused by sudden switching on or off of

pumps shall include:installation on the water line of valves to admit and trap air;installation on discharge lines of pumps of check valves with adjustable opening and closing;installation on a water line of check valves, breaking the water line into separate sections with low

static head in each section;discharge of water through pumps in the reverse direction during free rotation or full braking;installation at the beginning of a water line (on the discharge line of a pump) of air-water chambers

(caps) to soften the process of water hammer.Note: The following may be used to protect against water hammer: installation of safety valves and dampingvalves, releasing water from the discharge line into the intake line, admission of water into places of possible

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formation of discontinuities in the flow in a water line, installation of blank diaphragms which burst when thepressure rises above the permissible limit, use of water head columns, use of pumps with high inertia of rotatingmasses.

8.29. Protection of pipes from the increase in pressure caused by closing of a rotary valve (gatevalve) shall be provided by increasing the time of closure. With insufficient time of opening of a valve withthe type of drive used, additional protective measures shall be employed (installation of safety valves, aircaps, water-head columns, etc.).

8.30. Water lines are usually laid under ground. When justified on the basis of thermal engineeringand technical-economic calculations, on- and above-ground laying, laying in tunnels, as well as laying ofwater lines in tunnels together with other underground engineering lines except for pipelines transportingflammable and fuel liquids and flammable gases may be used. When fire fighting water lines are laid intunnels, on or above ground, fire hydrants shall be installed in manholes.

With underground laying, shutoff control and safety valves shall be installed in manholes(chambers).

Installation of cut-off valves without manholes is permitted when justified.8.31. The type of foundation used beneath a pipe shall be determined depending on the load-

bearing capacity of the soil and the load involved.In all soils except rocky, peaty and silty soils, pipes shall be laid on natural ground of undisturbedstructure, with leveling and shaping of the base where necessary.

For rocky soil, a smoothing base layer of sandy soil 10 cm thick above the highest projections shallbe used. It is permissible to use local soil (loam and sandy loam) for this purpose if it is compacted to a soilskeleton density of 1.5 metric ton/m3.

When pipe is laid in wet, cohesive soil (loam, clay), the need for a sandy base shall be establishedin the work plan depending on measures which may be taken to lower the water level, as well as the typeand design of pipes used.

In silt, peaty and other weak, water-saturated soils, pipes shall be laid on an artificial base.8.32. In cases where steel pipe is used, its external and internal surfaces shall be protected from

corrosion. The materials indicated in Paragraph 1.3 shall be used for this purpose.8.33. The selection of methods of protecting the external surface of steel pipe from corrosion shall

be based on data on the corrosive properties of the soil, as well as data on the possibility of corrosioncaused by stray currents.

8.34. The following shall be used to protect the inner surfaces of steel pipes from corrosion:stabilization treatment of the water; use of pipes with internal anti-corrosion protective coating.

8.36. Protection from corrosion of the concrete in cement-sand coatings and of pipes with steelcores from the effect of sulfate ions shall be provided by the use of insulating coatings in accordance withSNiP 2.03.11-85.

8.37. Protection of pipes with steel cores from corrosion caused by stray currents shall be providedin accordance with the requirements of the Instructions for Protection of Reinforced Concrete Structuresfrom Corrosion Caused by Stray Currents.

8.38. Pipe with steel cores having an outer layer of concrete with a density lower than the normaldensity with permissible crack opening width under the design load of 0.2 mm shall be provided withelectrochemical protection of pipes using cathodic polarization with a concentration of chlorine ions in thesoil of over 150 mg/L; with normal density of concrete and permissible crack opening with 0.1 mm, suchprotection shall be provided where the concentration of chlorine ions in the soil is over 300 mg/L.

8.39. When designing pipelines of steel and reinforced concrete pipe of all types, measures shall betaken to assure continuous conductivity of the pipes to allow the use of electrochemical protection fromcorrosion.

8.40. Cathodic polarization of pipes with steel cores shall be planned so that the protectivepolarization potentials created on the surface of the metal, measured at specially provided monitoring

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measurement points, are no less than 0.85 V and no more than 1.2 V with respect to a copper-sulfatecomparison electrode.

8.41. When pipe with a steel core is provided with electrochemical protectors, the polarizationpotential shall be determined with respect to a copper-sulfate comparison electrode mounted on the surfaceof the pipe, while when cathode stations are used it shall be protected with respect to a copper-sulfatecomparison electrode placed in the soil.

8.42. The depth of laying of pipe, measured to the bottom, shall be 0.5 m greater than thecalculated depth of penetration of the freezing temperature into the soil.

When pipelines are laid in areas of below-freezing temperatures the material of the pipe and jointcomponents shall satisfy the frost-resistance requirements.Note: Lesser depths of pipe laying may be used if measures are taken to prevent: freezing of fittings mounted onthe pipe; excessive reduction of the throughput capacity of the pipe as a result of formation of ice on the innersurfaces of the pipe; damage to pipes and joints as a result of freezing of water, deformation of the soil andtemperature stresses in the pipe wall materials; formation in the pipe of ice plugs when the flow of water isinterrupted due to damage to the pipe.

8.43. The calculated depth of penetration of freezing temperatures into the soil shall be establishedon the basis of observation of the actual depth to which the soil freezes during a cold winter with little snowand the experience of operation of pipes in the same area considering possible changes in previouslyobserved freezing depths as a result of planned modifications to the condition of the area (removal of snowcover, construction of improved roads, etc.).

When data are not available on the observed depth of penetration of freezing temperature into thesoil, and when it may change due to proposed modifications of the territory, it shall be determined by heat-engineering calculations.

8.44. To prevent heating of water during the summer, the depth at which pipes carrying drinkingwater are laid shall generally be no less than 0.5 m, measured to the top of the pipe. It is permissible to uselesser depth of placement of water lines or sections of a water supply network where justified by thermalengineering calculations.

8.45. When determining the depth of placement of water lines and water distribution networks withunderground laying, external loads from vehicles and conditions of crossings of other undergroundstructures and lines shall be considered.

8.46. The selection of the diameters of pipes for water lines and water distribution networks shallbe based on technical and economic calculations, considering the operating conditions in case of emergencydisconnection of individual sections.

The diameter of water supply pipes combined with fire fighting pipes in population centers andindustrial enterprises shall be no less than 100 mm, in rural population centers—no less than 75 mm.

8.47. The hydraulic slope used to determine head losses in pipes when transporting water withoutclearly expressed corrosive properties and not containing suspended impurities, the deposition of whichmight lead to significant constriction of pipes, shall be taken in accordance with obligatory Appendix 10.

8.48. For existing networks and water lines, measures shall be taken as necessary to restore andpreserve the throughput capacity of pipes by cleaning the inner surfaces of steel pipes and applying an anti-corrosion protective coating; in exceptional cases, by agreement with the construction commissions of theunion republics and with the proper engineering and economic basis, the actual head losses may be used.

8.49. During the planning of new and reconstruction of existing water supply systems, methodsand devices shall be provided for systematic determination of the hydraulic resistance of pipes over controlsections of pipes and networks.

8.50. The location of water lines on general plans, as well as minimum distances in plan and atcrossings from the outer surfaces of pipes to facilities and engineering networks shall be taken inaccordance with SNiP II-89-80.

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8.51. With parallel placement of several water lines (new or additions to existing lines) the distancein plan between the outer surfaces of pipes shall be established considering the conduct and organization ofwork and the need for protection of neighboring water lines from damage in case of an emergency in oneline:

with a permissible decrease in water flow rate to consumers as provided for in Paragraph 8.2—according to Table 35 depending on the pipe material, internal pressure and geological condition;

when there is reserve capacity at the ends of water lines, permitting interruptions in the supply ofwater, the volume of which corresponds to the requirements of Paragraph 9.6—from Table 35 as for pipelaid in rocky soil.

In individual sections of water lines, including areas where water lines are laid through built-upterritories and in the territories of industrial enterprises, the distances presented in Table 35 may be reducedif the pipe is laid on an artificial base, in a tunnel, sheath or when other laying methods are used whichprevent damage to neighboring water lines in case of an emergency in one of them. The distance betweenwater lines in this case shall assure the possibility of performing work both when laying the pipe and duringsubsequent repair.

8.52. When water lines are laid in tunnels the distance from the wall of the tunnel to the innersurface of the protective structures and walls of other pipes shall be no less than 0.2 m; where fittings aremounted on a pipe the distance to the protective structures shall be taken in accordance with Paragraph8.63.

8.53. Crossings of pipes under railroads of categories I, II and III, of the general network, and alsobeneath highways of categories I and II shall be in sheaths, generally using the closed method of performingwork. When justified, pipes may be laid in tunnels.

Crossing of pipes beneath other types of railroad tracks and roads is permissible without sheaths,though steel pipes and the open method of working shall generally be used.Notes: 1. Laying of pipes on railroad bridges and viaducts, pedestrian bridges over tracks, in railroad, motorvehicle and pedestrian tunnels, and also in water delivery pipes is not permitted.3. Sheaths and tunnels beneath railroads with the open method of working shall be designed in accordance with

SNiP 2.05.03-84.

Table 35Soil type (nomenclature of SNiP II-15-74*)

Pipe material Diameter,mm

Rocky Large-lump rocks,gravelly sand,

coarse sand, clay

Medium sand, finesand, powdery

sand, sandy loam,loam, soils withplant residue,

peaty soilsPressure, MPa (kgf/cm2)

≤≤≤≤1 (10) >1 (10) ≤≤≤≤1 (10) >1 (10) ≤≤≤≤1 (10) >1 (10)Distance in plan between outer surfaces of pipes, m

Steel Up to 400 0.7 0.7 0.9 0.9 1.2 1.2Steel From 400

to 10001 1 1.2 1.5 1.5 2

Steel Over 1000 1.5 1.5 1.7 2 2 2.5Cast iron Up to 400 1.5 2 2 2.5 3 4Cast iron Over 400 2 2.5 2.5 3 4 5Reinforced concrete Up to 600 1 1 1.5 2 2 2.5

* Translator’s note: Partly illegible, probably: III-15-74.

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Soil type (nomenclature of SNiP II-15-74*)

Pipe material Diameter,mm

Rocky Large-lump rocks,gravelly sand,

coarse sand, clay

Medium sand, finesand, powdery

sand, sandy loam,loam, soils withplant residue,

peaty soilsPressure, MPa (kgf/cm2)

≤≤≤≤1 (10) >1 (10) ≤≤≤≤1 (10) >1 (10) ≤≤≤≤1 (10) >1 (10)Distance in plan between outer surfaces of pipes, m

Reinforced concrete Over 600 1.5 1.5 2 2.5 2.5 3Asbestos cement Up to 500 1.5 2 2.5 3 4 5Plastic Up to 600 1.2 1.2 1.4 1.7 1.7 2.2Plastic Over 600 1.6 — 1.8 — 2.2 —Notes: 1. With parallel laying of water pipes at different levels the distances given in the table shall be increasedbased on the difference in levels of laying of the pipes.2. For water lines differing in diameter and pipe material the distances shall be accepted for the pipe requiringthe greater distances.

8.54. The vertical distances from the base of the rail of a railroad track or from the surface of amotor vehicle road to the top of a pipe, sheath or tunnel shall be taken in accordance with SNiP II-89-80.

Burying of pipelines at crossings where heaving soils are present shall be determined by thermalcalculation in order to prevent frost heaving of the soil.

8.55. The distance in plan from the edge of a sheath, or in case a sheath ends in a manhole—fromthe outer surface of the wall of the manhole, shall be taken as:

when crossing railroads—8 m from the axis of the outer track, 5 m from the base of a fill, 3 mfrom the brow of a cut and from the outermost water deflecting structures (cuvettes, channels, ditches anddrains);

when crossing highways—3 m from the brow of the earthen right-of-way or the base of a fill, thebrow of a cut, the outer brow of a ditch or other water deflecting structure.

The distance in plan from the outer surface of a sheath or tunnel shall be no less than:3 m—to traction power line poles;10 m—to booms, crosses and points of attachment of “drawing off” cables to the rails of electrified

railroads;30 m—to bridges, water drainage pipes, tunnels and other artificial structures.

Note: The distance from the edge of a sheath (or tunnel) shall be refined depending on the presence of long-distance communications, signaling and other cables laid along the road.

8.56. The inside diameter of a sheath shall be taken when work is performed:by the open method—200 mm greater than the outside diameter of the pipe;by the closed method—depending on the length of the crossing and the diameter of the pipe in

accordance with SNiP III-4-80.Note: A single sheath or tunnel may contain several pipes, and joint laying of pipes and other lines (electricalcables, communications lines, etc.) is also permissible.

8.57. Crossing of pipes over railroads shall be in sheaths on special trestles considering therequirements of Paragraphs 8.55 and 8.59.

8.58. When crossing an electrified railroad, steps shall be taken to protect pipes from corrosioncaused by stray currents.

8.59. When designing crossings of category I, II and III railroads of the general network, as well ascategory I and II motor vehicle roads, steps shall be taken to prevent erosion or flooding of the roads incase of damage to pipes.

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Manholes with cut-off valves shall generally be placed on both sides of a pipe crossing beneath arailroad.

8.60. The design of crossings of railroads and vehicle roads shall be coordinated with agencies ofthe Ministry of Railways or Ministry of Construction and Operation of Highways of the union republics.

8.61. When pipes cross streams the number of lines of the inverted siphon shall be no less thantwo; if one line is disconnected, 100% of the design water flow shall be supported by the other. The lines ofthe inverted siphon shall be made of steel pipe with anticorrosion insulation, protected from mechanicaldamage.

The design of an inverted siphon crossing a navigable stream shall be coordinated with agencies ofthe union republic River Fleet Directorates.

The depth of placement of the underwater portion of a pipe to the top of the pipe shall be no lessthan 0.5 m below the bottom of the stream, and within the channel of navigable streams no less than 1 m.The possibility shall be considered of erosion and reforming of the stream bed.

The clear distance between siphon lines shall be no less than 1.5 m.The slope angle of the ascending parts of the siphon shall be not over 20° to the horizontal.Manholes and cross connections with valves shall be provided on both sides of a siphon.The level in the manholes of a siphon shall be 0.5 m higher than the maximum water level in the

stream with 5% probability.8.62. Bends in the horizontal or vertical plane of pipelines made of bell-mouthed pipe or connected

with couplings, in cases when the forces arising cannot be accepted by the pipe joints, shall be providedwith supports.

On welded pipelines, supports shall be provided where bends are located in manholes or where thebend angle in the vertical plane has an upward convexity of 30° or more.Note: On pipelines of bell-mouthed pipe or joined with couplings with operating pressure up to 1 MPa(10 kgf/cm2) with bend angles of up to 10°, supports are not necessary.

8.63. When determining the dimensions of manholes, the minimum distances to the internalsurfaces of the manhole shall be as follows:

• from pipe walls with pipe diameter up to 400 mm—0.3 m, from 500 to 600 mm—0.5 m, over 600mm—0.7 m;

• from the plane of a flange with pipe diameter up to 400 mm—0.3 m, over 400 mm—0.5 m;• from the edge of a bell turned toward a wall with pipe diameter up to 300 mm—0.4 m, over 300

mm—0.5 m;• from the bottom of a pipe to the floor with pipe diameter up to 400 mm—0.25 m, from 500 to 600

mm—0.3 m, over 600 mm—0.35 m;• from the top of the shaft of a gate valve with rising spindle—0.3 m, from the control wheel of a

gate valve with nonrising spindle—0.5 m.The height of the working portion of manholes shall be at least 1.5 m.8.64. In cases where water line air inlet valves are located in manholes, a ventilation tube shall be

installed which, if the water line carries drinking water, shall be equipped with a filter.8.65. Ribbed steel or cast iron brackets shall be mounted on the throat and walls of a manhole, the

use of portable metal ladders to enter the manhole is permitted.Platforms in accordance with Paragraph 12.7 shall be used to service fittings in manholes when

necessary.8.66. Double heating covers shall be installed on manholes (when needed); hatches with seals shall

be used when necessary.

9. WATER STORAGE VESSELS

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General Instructions

9.1. Water storage vessels used in water supply systems include regulating, fire, emergency andcontact water storage vessels.

9.2. The volume of regulating water Wr, m3, in vessels (tanks, water towers, counter-tanks, etc.)shall be determined on the basis of the graph of arrival and departure of water volumes, or if such graphsare not available by means of the equation

( )( ) ( )W Q K K K K

K Kr day.max p h p h

h h= − + −

−

1 11/

, (33)

where Qday.max is the water flow on a day of maximum water consumption, m3/day;Kp is the ratio of the maximum hourly water flow into the regulating vessel at water treatment plants,pumping plants or into the water supply network from the regulating vessel to the average hourly flow on aday of maximum water consumption;Kh is the hourly nonuniformity of water flow out of the regulating vessel or from a water supply networkwith a regulating vessel, defined as the ratio of the maximum hourly outflow to the average hourly flow ona day of maximum water consumption.

The maximum hourly outflow of water directly for the needs of consumers having no regulatingvessels shall be taken equal to the maximum hourly water consumption. The maximum hourly outflow ofwater from a regulating vessel through pumps feeding the water supply network, when the network has aregulating vessel, is determined from the maximum hourly throughput of the pumping plant.

In vessels at water treatment plants an additional volume of water shall be provided for washing offilters, defined in accordance with Paragraph 6.117.Note: With justification, a volume of water may be held in vessels to regulate the daily nonuniformity of waterconsumption.

9.3. A volume of water for fire fighting shall be provided in cases when it is technically impossibleor economically undesirable to obtain the quantity of water necessary to extinguish a fire directly from thewater supply source.

9.4. The volume of water held for fire fighting shall be determined to support:extinguishing of fires from outdoor hydrants and indoor fire valves in accordance with Paragraphs

2.12-2.17, 2.20, 2.22-2.24;special fire fighting devices (sprinklers, drenchers, etc., not having their own tanks) in accordance

with Paragraphs 2.18 and 2.19;the maximum drinking and process water requirements for the entire period of fire fighting,

considering the requirements of Paragraph 2.21.Note: When determining the volume of water for fire fighting to be held in tanks, it is permissible to considerwater added as the fire is being fought if the supply of water to the tanks is provided by category I and II watersupply systems.

9.5. The volume of water in water towers for fire fighting shall be calculated for ten minutesfighting of one outdoor and one indoor fire with the maximum simultaneous flow of water for other needs.Note: With justification it is permitted to store the full fire fighting volume as defined in Paragraph 9.4 in watertowers.

9.6. When water is fed through a single water line into vessels, the following shall be provided:an emergency volume of water to support during the time of recovery from an emergency on the

water line (Paragraph 8.4) a water flow rate for domestic and drinking water requirements amounting to70% of the design mean hourly water consumption and for process requirements according to theemergency graph;

an additional volume of water for fire fighting as defined in Paragraph 9.4.Notes: 1. The time required to restore the volume of water flow shall be taken as 36-48 hours.

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2. Restoration of the volume of water flow shall be provided by reducing water consumption or by the use ofreserve pumping units.3. The additional volume of water for fire extinguishing purposes need not be provided if the length of the singlewater supply line is not over 500 m to population centers with up to 5000 residents, or to industrial andagricultural enterprises with a water flow rate for outdoor fire fighting of not over 40 L/s.

9.7. The volume of water in vessels before boost or water circulating pumping plants whichoperate uniformly shall be taken as 5-10 minutes of throughput of the pump with the greatest throughput.

9.8. The contact volume of water to support the required contact time of water with reagents shallbe determined in accordance with Paragraph 6.167. The contact volume may be reduced by the fire andemergency volumes, if any.

9.9. Vessels and their equipment shall be protected from freezing of the water.9.10. In drinking water vessels, the fire and emergency volumes of water shall be exchanged during

a period of not over 48 hours.Note: With justification, the water exchange time in vessels may be increased to 3-4 days. Circulationpumps shall be provided, the throughput of which shall be determined in order to replace the water in thevessels during a period of not over 48 hours considering the arrival of water from the water supply source.

9.11. The design of vessels and water towers shall be taken from Paragraph 14.18.

Vessel Equipment

9.12. Water tanks and water towers shall be equipped with: incoming and outgoing pipes or a combinedfill-outflow pipe, overflow device, a drainage pipe, ventilation device, stirrups or ladders, hatches for entryof people and transportation of equipment.

Depending on the purpose of the vessel, the following shall be additionally provided:a device to measure the water level, monitor the vacuum and pressure in accordance with

Paragraph 13.36;skylights 300 mm in diameter (in nondrinking water tanks);a wash water line (movable or stationary);a device to prevent overflow of water from the vessel (automatic control or float valve on the feed

pipe);a device to clean air entering the vessel (in drinking water tanks).9.13 A diffuser with a horizontal edge or a chamber, the top of which shall be 50-100 mm above

the maximum water level in the vessel, shall be provided at the end of the fill pipe for tanks and watertowers.

9.14. The outflow pipe of a tank shall have a confusor; with a pipe diameter up to 200 mm it ispermissible to use an intake valve located in a well (see Paragraph 7.4).

The distance from the edge of the confusor to the bottom and walls of the vessel or well shall bedetermined by calculation so that the speed of approach of water to the confusor is no greater than thespeed of movement of water in the intake cross section.

The horizontal edge of a confusor built into the bottom of a tank and the top of the well shall be 50mm higher than the concreting on the bottom.

A screen shall be provided for the outflow pipe or well.Outside a tank or water tower on the outflow (fill-outflow) pipe there shall be a device for filling of

tank trucks and fire trucks.9.15. The overflow device shall be designed for a flow equal to the difference between the

maximum intake and minimum outflow of water. The water level above the edge of the overflow shall benot over 100 mm.

In tanks and water towers designed for drinking water a hydraulic seal shall be provided on theoverflow device.

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9.16. The drainage pipe shall be planned with a diameter of 100-150 mm depending on the volumeof the vessel. The bottom of the vessel shall have a slope of no less than 0.005 in the direction of thedrainage pipe.

9.17. The drainage and overflow pipes shall be connected (without submerging their ends):from vessels for nondrinking water—to any type of sewer with an open stream or to an open canal;from drinking water vessels—to a storm sewer or an open canal with an open stream.When an overflow pipe is connected to an open canal, a screen with 10 mm apertures shall be

attached to the end of the pipe.When it is impossible or undesirable to discharge water through a drainage pipe by gravity flow, a

well shall be provided to allow the water to be pumped away by means of mobile pumps.9.18. Flow of air into and out of vessels as the water level changes, as well as air exchange in tanks

for storage of fire fighting and emergency water, shall be provided through ventilating devices whichprevent the formation of a vacuum of over 80 mm of water.

The air space in tanks with the maximum water level, from the water to the bottom rib of the cover,shall be from 200 to 300 mm. Beams and supports may be under water, but air exchange shall be allowedamong all sections of the cover.

9.19. Hatches shall be located near the ends of fill, outflow and overflow pipes. Hatch covers indrinking water tanks shall have locking and sealing devices. Hatches on tanks shall extend above the coverby at least 0.2 m.

Potable water tanks require complete sealing of all hatches.9.20. Pressurized tanks and water towers used with a high pressure fire extinguishing system shall

be equipped with automatic devices permitting them to be disconnected when fire pumps are started.

Tanks

9.21. The total number of tanks of one purpose at one facility shall be no less than two.In all tanks at a facility the maximum and minimum levels of fire, emergency and regulating

volume shall be set at identical levels.When one tank is disconnected, the remaining tanks shall contain no less than 50% of the fire and

emergency volumes of water.The equipment of tanks shall assure the possibility of independent connection and emptying of each

tank.A single tank may be used if it does not contain fire or emergency water.9.22. Gate valve chamber structures with tanks shall not be rigidly connected to tank structures.

Water Towers

9.23. Water towers may be designed with or without a shade roof depending on the operating mode of thetower, volume of the tank, climatic conditions and water temperature in the water supply source.

9.24. A water tower may be used to contain production rooms of a water supply system, notproducing dust, smoke or exhaust gases.

9.25. When pipes are rigidly attached to the bottom of the tank of a water tower, compensatorsshall be provided on the pipe supports.

9.26. A water tower which does not fall within the lightning protection zone of other structuresshall be equipped with its own lightning protection.

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Fire Tanks and Bodies

9.27. The store of water for fire fighting in special tanks or open bodies of water is permitted forthe enterprises and population centers indicated in note 1 of Paragraph 2.11.

9.28. The volume of fire tanks and bodies of water shall be determined based on the calculatedwater flow and time for extinguishing of fires in accordance with Paragraphs 2.13-2.17 and 2.24.Notes: 1. The volume of open bodies of water shall be computed considering possible evaporation of water andformation of ice. The height of the edge of an open body of water shall be at least 0.5 m above the maximum waterlevel.2. Fire tanks, bodies of water and entry wells shall be freely accessible to fire engines over improved roads inaccordance with Paragraph 14.6.3. The locations of fire tanks and bodies of water shall be marked with signs in accordance with GOST 12.4.009-83.

9.29. The number of fire tanks or bodies of water shall be no less than two, each of which shallstore 50% of the volume of water required for extinguishing fires.

The distance between fire tanks or bodies or water shall be taken as in Paragraph 9.30, with thewater supply for any point of a fire provided by two neighboring tanks or bodies of water.9.30. Fire tanks or bodies of water shall be located in order to serve buildings within a radius of:

with pump trucks available—200 m;with engine-driven pumps available—100-150 m depending on the type of pump.In order to increase the radius served, it is permissible to lay dead-end pipes from tanks or bodies

of water with a pipe length of not over 200 m, observing the requirements of Paragraph 9.32.The distance from the point where water is taken from tanks or bodies of water to buildings of fire

resistance classes III, IV and V and to open storage facilities for combustible materials shall be no less than30 m, to buildings of fire resistance classes I and II—no less than 10 m.

9.31. Water for filling of fire tanks and bodies of water shall be provided through pipes from watersupply networks; it is permissible to fill them through fire hoses up to 250 m in length, and by agreementwith agencies of the State Fire Inspectorate, up to 500 m in length.

9.32. If it is difficult to take water directly from a fire tank or body of water by the use of pumptrucks or engine-driven pumps, receiving wells with a volume of 3-5 m3 shall be provided. The diameter ofthe pipe connecting the fire tank or body of water to a receiving well shall be taken to allow transmission ofthe design flow of water for outdoor fire fighting, but no less than 200 mm. A manhole with a cut-off valve,the wheel of which shall extend beneath the hatch cover, shall be provided before the receiving well.

The connecting pipe shall be provided with a screen at the end in the body of the water.9.33. Fire tanks and bodies of water need not be equipped with overflow and drainage pipes.

10. SANITARY PROTECTION ZONES

General Instructions

10.1. Sanitary protection zones* shall be provided for all domestic-drinking water supply linesplanned or reconstructed in order to assure their sanitary-epidemiological reliability.

10.2. Water line zones shall include a zone in the area of the water supply source at the pointwhere the water is taken (including water intake facilities) and a zone and a sanitary-protective strip**

* In what follows, “zones.”** In what follows, “strip.”

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containing water line facilities (pumping plants, water treatment plants, vessels) and the sanitary-protectionstrips of water lines.

The zone of a water supply source at the water intake shall consist of three belts: the first—strictregime belt, the second and third—limited regime belts. The zone of water line facilities shall consist of thefirst belt and strip (where water line facilities are located outside the second belt of the water supply sourcezone).

10.3. The plan for sanitary protection zones of a water line shall be developed with the use of datafrom a sanitary-topographic survey of the areas planned for inclusion in the zones and strips, as well as thecorresponding hydrological, hydrogeological, engineering geological and topographic materials.

10.4. The plan for the sanitary protection zones of a water line shall define: the limits of the belts inthe water supply source zone, zones and strips of water line facilities and strips of water lines, the list ofengineering measures to be taken for organization of zones (objects to be constructed, structures to be takendown, improvements, etc.) and a description of the sanitary regime in the zones and strips.

10.5. The plan for the sanitary protection zone of a water line shall be coordinated with theExecutive Committee of the Local Council of Peoples’ Deputies, with agencies of the sanitary-epidemiologic service, geological agencies (when groundwater is used), as well as other interestedministries and departments, and approved according to the established procedure.

10.6. Engineering measures involved in elimination of contamination of areas, streams, bodies ofwater and aquifers in the second and third belts of zones, and also within strips, shall be undertaken at theexpense of enterprises which are the sources of the contamination.

10.7. The plan for water line zones shall be developed considering the development of the watersupply system for the future.

BOUNDARIES OF SANITARY PROTECTION ZONES

Surface Water Supply Sources

10.8. The boundaries of the first belt of the zone of a surface water supply source, including awater supply canal, shall be established at the following distances from the water intake:

a) for streams (rivers, canals):upstream—at least 200 m;downstream—at least 100 m;on the bank adjacent to the water intake—at least 100 m from the water line during the summer-

fall low water period;in the direction of the opposite bank: with a stream width of less than 100 m—the entire water area

and the opposite bank with a width of 50 m from the water line during the summer-fall low-water period,and with a stream width of over 100 m—the water area over a width of at least 100 m;

at bowl-shaped water intakes, the entire water area of the bowl and the area around it in a strip ofat least 100 m is included in the first belt;

b) for bodies of water (reservoirs, lakes):the water area in all directions—at least 100 m;on the bank adjacent to the water intake—at least 100 m from the water line at the normal level of

the reservoir in the summer-fall low-water period.10.9. The boundaries of the second belt of the zone of a stream shall be established:

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upstream, including tributaries—based on the flow speed of the water, averaged across the widthand over the length of the stream or in individual sections and the time of flow of water from the boundaryof the belt to the water intake with the monthly average water flow during a 95% probable summer-falllow-water period, no less than 5 days for climate regions IA, B, C, D and IIA and no less than three

days for other climate regions;downstream—at least 250 m;lateral boundaries—at a distance from the water level during the summer-fall low-water period—

with level relief—500 m, with mountainous relief—to the ridge of the first slope turned toward the stream,but no more than 750 m for a gentle slope and 1000 m for a steep slope.

If a river has a backwater or reverse flow, the distance of the lower boundary of the second beltfrom the water intake shall be established as a function of the hydrological and meteorological conditions,by agreement with agencies of the sanitary-epidemiological service.

On navigable rivers and channels the second belt of the zone shall include the water area adjacentto the water intake within the fairway.Note: In some cases, depending on local conditions, the lateral boundaries of the second belt may be increased byagreement with agencies of the sanitary-epidemiological service.

10.10. The boundaries of the second belt of the zone in a body of water, including tributaries, shallbe established from the water intake:

on the body of water in all directions for a distance of 3 km with up to 10% winds toward the waterintake and 5 km with over 10% of such winds;

the lateral boundaries shall be from the water level at the normal backwater level in a reservoir andthe summer-fall low-water period in a lake for a distance in accordance with Paragraph 10.9.

10.11. The boundaries of the third belt of the zone of a surface water supply source shall beupstream and downstream on a stream or in all directions in the water area of a body of water the same asfor the second belt; the lateral boundaries shall be along the divide, but no more than 3-5 km from thestream or body of water.

Underground Water Supply Sources

10.12. The boundaries of the first belt in the zone of an underground water supply source shall beestablished from an individual water intake (well, mine shaft, catchment) or from the edges of water intakestructures of a group water intake for distances of :

30 m when protected groundwater is used;50 when insufficiently protected groundwater is used.The bank area between the water intake and a surface source of water supply shall be included

within the boundaries of the first belt of the zone of infiltration water intakes if the distance between them isless than 150 m.

For underflow water intakes and the section of a surface source feeding an infiltration water intakeor used to artificially supplement groundwater reserves, the boundaries of the first belt of the zone shall beassigned as for surface sources of water supply in accordance with Paragraph 10.8.Notes: 1. For water intakes located in the area of an object which excludes the possibility of contamination of soiland groundwater, and also for water intakes located in favorable sanitary, topographic and hydrogeologicalconditions, the dimensions of the first belt of the zone may be reduced by agreement with local agencies of thesanitary-epidemiological service, but shall be no less than 15 and 25 m, respectively.2. Protected groundwater includes water in artesian and nonartesian aquifers having a continuous impermeableroof throughout all belts of the zone, excluding the possibility of partial influx from overlying insufficientlyprotected aquifers.

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Insufficiently protected groundwater includes:water in the first nonartesian aquifer below the surface, fed in the area where it is located;water in artesian and nonartesian aquifers which under natural conditions or as a result of use of the waterintake are fed in the area of the zone from overlying insufficiently protected aquifers throughhydrogeological apertures or penetrating rock, the roof, or from streams and bodies of water by directhydraulic connection.

10.13. With artificial supplementing of groundwater reserves the boundaries of the first belt of thezone shall be established from closed-type infiltration openings (boreholes, mine shafts) —50 m, from opentypes (pools, etc.) —100 m.

10.14. The boundaries of the second belt of the zone of an underground water supply source shallbe established by calculation, considering the time of movement of microbial contamination of water to thewater intake, taken as a function of the climate regions and protection of groundwater as 100 to 400 days.

10.15. The boundary of the third belt of the zone of an underground water supply source shall bedetermined by calculation, considering the time of movement of chemical contamination of water to thewater intake, which shall be greater than the time of operation of the water intake, but no less than 25years.

10.16. With infiltration feeding of an aquifer, and also with artificial supplementing ofgroundwater reserves from a surface source, the second and third belts of the zone of the surface source ofwater supply shall be taken in accordance with Paragraphs 10.9-10.11.

Sites of Water Line Facilities

10.17. The boundary of the first belt of the zone of water supply facilities shall coincide with thefencing of the site of the facilities and shall be located at the following distances:from the walls of tanks of filtered (drinking) water, filters (except pressurized), contact clarifiers with openwater surfaces—at least 30 m;from the walls of other facilities and water towers—at least 15 m.Notes: 1. By agreement with agencies of the sanitary-epidemiological service the first belt of the zone relative tostanding water towers, as well as pumping plants operating without open streams, need not be established.2. When water line facilities are located in the area of an enterprise, these distances may be reduced by agreementwith local agencies of the sanitary-epidemiological service, but shall be no less than 10 m.

10.18. The sanitary-protective strip around the first belt of the zone of water line facilities locatedoutside the second belt of the zone of a water supply source shall have a width of no less than 100 m.Note: When the sites of water line facilities are located in the area of an object, the width of the strip may bereduced by agreement with agencies of the sanitary-epidemiological service, but shall be no less than 30 m.

10.19. The sanitary-protective zone from industrial and agricultural enterprises to water treatmentplant facilities shall be taken as for population centers depending on the harmfulness of the productionprocess.

Water Lines

10.20. The width of the sanitary-protective strip of water lines passing through unimprovedterritories shall be measured from the outermost water lines:when laid in dry soils—at least 10 m for line diameters of up to 1000 mm and at least 20 m for largerdiameters; in moist soils—no less than 50 m regardless of pipe diameter.

When water lines are laid through built-up areas the width of the strip may be reduced byagreement with agencies of the sanitary-epidemiological service.

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SANITARY MEASURES IN ZONES

Surface Water Supply Sources

10.21. The area of the first belt in the zone of a surface water supply source shall be leveled,fenced and planted, with the fencing provided in accordance with Paragraph 14.4.

10.22. The boundaries of the water area of the first belt of a zone shall be marked with warningsigns on the ground and buoys. Lighted buoys shall be placed above submerged water intakes located in thenon-navigable portion of a stream or body of water; when located in the navigable portion, buoys shall beplaced outside of channels.

10.23. Guard signals (alarms) shall be provided for the area of the first belt of a zone.10.24. In the area of the first belt of a zone:a) the following are forbidden:all types of construction, with the exception of reconstruction or expansion of basic water line

facilities (utility buildings not directly related to the supply or treatment of water shall be located outsidethe limits of the first belt of a zone);

placement of housing or public buildings, residences, including housing for water line workers;laying of various types of pipelines, except for pipelines servicing water line facilities;drainage of wastewater, swimming, watering and grazing of cattle, washing of clothing, fishing,

application of pesticides and fertilizers;b) buildings shall be equipped with sewers draining wastewater into the nearest residential or

industrial sewerage or local treatment facilities located outside the first belt of the zone, considering thesanitary regime of the second belt. If sewerage is not available, impermeable cesspools shall be constructed,located so as to exclude contamination of the area of the first belt during removal of sewage;

c) surface water shall be carried away beyond the limits of the first belt;d) only improvement thinning and maintenance cutting of trees are permitted.10.25. The following are required in the second belt of the zone of a surface water supply source:a) regulation of the allocation of land for population centers, medical treatment and health resort

institutions, industrial and agricultural objects, as well as possible changes in the technology of industrialenterprises involving an increase in the danger of pollution of water supply sources with wastewater;

b) improvement of industrial, agricultural and other enterprises, population centers and individualbuildings, provision of organized water supply, sewerage, the construction of impermeable cesspools,organization of removal of contaminated surface wastewater, etc.

c) assurance of a degree of treatment of domestic, industrial and storm wastewater discharged intostreams and bodies of water satisfying the requirements of the Principles of Water Law of the USSR andunion republics and Rules for Protecting Surface Waters from Wastewater Pollution;

d) only improvement thinning and maintenance cutting of trees.10.26. The following are forbidden in the second belt of the zone of a surface water supply source:a) contamination of areas with sewage, garbage, manure, industrial wastes, etc.;b) placement of storage facilities for fuel and lubricants, poisons and mineral fertilizers, holding

lagoons, tailings ponds and other objects which may cause chemical pollution of water supply sources;c) placement of cemeteries, burial grounds for animal refuse, sewage disposal fields, filtration

fields, irrigated agricultural fields, manure pits, silage trenches, animal husbandry and poultry enterprisesor other objects which may cause microbial contamination of water supply sources;

d) the use of fertilizers and pesticides.10.27. Within the second belt of the zone of a surface water supply source, in addition to the

requirements of Paragraphs 10.25 and 10.26:

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poultry raising, washing of clothing, swimming, tourism, water sports, beaches and fishing arepermitted in fixed locations if special conditions are met as coordinated with agencies of the sanitary-epidemiological service;

crossings, bridges and piers shall be located;if shipping is present, ships shall be equipped with special devices for collection of wastewater and

solid wastes, dumping stations and receivers for collection of solid wastes are set up on piers, and landingstages and guard ships shall be equipped with receivers for collection of sewage;

sand and gravel mining from the stream or body of water, as well as dredging, are forbidden;location of pastures is forbidden in a shoreline strip at least 300 m in width.

10.28. Within the third belt of the zone of a surface water supply source, the sanitary measuresindicated in Paragraph 10.25 shall be implemented.

10.29. In forests located within the third belt of a zone it is permitted to cut down trees for primaryand intermediate use and to allocate standing timber to wood cutting enterprises (wood material bases), aswell as forest areas for long-term use.

10.30. When canals and reservoirs are used as water supply sources, they shall be periodicallycleansed of bottom sediment and aquatic vegetation. The use of chemical methods to control overgrowth ofcanals and reservoirs is permitted if preparations are used which are permitted by agencies of the sanitary-epidemiological service.

Underground Water Supply Sources

10.31. The sanitary measures indicated in Paragraphs 10.21, 10.23 and 10.24 shall beimplemented in the first belt of the zone of an underground water supply source.Note: Warming signs need not be used at water intakes for groundwater of agricultural objects.

10.32. The sanitary measures set forth in Paragraphs 10.25 a, b, d and 10.26 shall be applied inthe second belt of the zone of underground water supply sources.

10.33. The sanitary measures employed in the second belt of a zone, in addition to those listed inParagraph 10.32, shall include:

marking, sealing or restoration of all old, inactive, defective or improperly operated wells and mineshafts which create any danger of pollution of the aquifer used;

regulation of the drilling of new wells;prevention of pumping of spent water into underground strata, underground storage of solid waste

and working of underground mineral resources, as well as the liquidation of inverted wells and mine shaftswhich may pollute aquifers.

10.34. The sanitary measures indicated in Paragraph 10.25 a, 10.26 b, and 10.33 shall beemployed in the third belt of the zone of an underground water source.Note: When protected groundwater is used and by agreement with agencies of the sanitary-epidemiologicalservice it is permissible to place the objects indicated in Paragraph 10.26 b within the third belt of a zone.

10.35. Sanitary measures in all belts of the zone of underflow water intakes and the sections of asurface source feeding an infiltration water intake or used for artificial supplementing of groundwaterreserves shall be performed just as for surface water supply sources.Sites of Water Line Facilities

10.36. Within the first belt of the zone of a water line facility site, the sanitary measures indicatedin Paragraphs 10.21 and 10.24, and the guarding and protective facilities indicated in Paragraph 14.5 shallbe provided.

10.37. The sanitary measures called for in Paragraph 10.32 shall be provided within the sanitary-protective strip of water line facility sites.

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Water Lines

10.38. Within the sanitary-protective strip of water lines there shall be no sources of pollution ofsoil and groundwater (restrooms, refuse (rubbish) pits, manure storage areas, trash receivers, etc.).

In water line sections where the strips are adjacent to these pollution sources, plastic or steel pipeshall be used.

10.39. It is forbidden to lay water lines in the territory of garbage dumps, sewage disposal fields,filtration fields, irrigated agricultural fields, cemeteries, burial grounds for animal refuse, or throughindustrial and agricultural enterprises.

11. RECYCLED WATER COOLING SYSTEMS

General Instructions

11.1. Water supply systems shall provide for circulating of water over an entire industrialenterprise or in the form of closed loops for individual facilities, shops or installations.

The number of circulating water cooling systems at an enterprise shall be established consideringthe production processes, requirements for quality, temperature and pressure of water, location of waterconsumers on the general plan and construction sequence.

In order to reduce the diameter and length of water supply network pipes, separate watercirculating systems shall be used at an industrial enterprise for individual processes, shops or installations,placing them as close as possible to water consumers.

11.2. When planning circulating water cooling systems, the possibility of using the low-potentialheat of warmed water shall be considered.

11.3. A circulating water supply system shall be designed with water taken from processinstallations without breaking the stream with sufficient head for the water to be fed to coolers, except incases when the stream is broken according to the process installations design.

11.4. Circulating water supply systems shall use natural and wastewater with appropriate cleaningand treatment. The use of treated wastewater shall be coordinated with agencies of the sanitary-epidemiological service.

11.5. When planning circulating water supply facilities, the requirements of Sections 7, 12 and 13shall be considered.

11.6. Circulating water shall not cause corrosion of pipes, equipment and heat-exchange apparatus,biological overgrowth, or precipitation of suspended matter and salt deposits onto heat exchanger surfaces.

In order to assure that these requirements are met, the corresponding purification and treatment ofadded and circulating water shall be provided.

11.7. Selection of the composition and dimensions of facilities and equipment for cleansing,processing and cooling of water shall be performed to assure maximum utilization of these facilities.

WATER BALANCE IN SYSTEMS

11.8. A water balance shall be composed for circulating water systems, considering the losses,necessary discharges and addition of water to the system to compensate for losses.

11.9. In composing the balance, water losses from the system shall include:a) irrecoverable consumption (taking of water from the system for process needs);b) water lost to evaporation during cooling qevap, m3/hr, as determined by the equation

qevap = Kevap ∆t qcool (34)

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where ∆t = t1 – t2 is the temperature drop of the water in Celsius degrees, defined as the difference betweenthe temperature of water arriving at the cooler (pond, spray pool or tower) t1 and the cooled water t2;qcool is the consumption of cooling water, m3/hr;Kevap is a coefficient considering the heat transfer by evaporation as a fraction of the total heat transfer,used for spray pools and cooling towers as a function of the air temperature (as measured by drythermometer) as in Table 36, for cooling reservoirs (ponds) as a function of the natural temperature in thestream of water from Table 37.

When a product is cooled in sprinkler-type heat exchange equipment the water loss to evaporationas calculated by this equation shall be doubled.

c) water losses in spray pools, towers and sprinkler heat exchange equipment due to water carriedaway with the wind P2, taken from Table 38;

d) water losses in treatment facilities, determined by calculation considering the instructions ofSection 6;

e) water losses to seepage from cooling reservoirs (ponds) with permeable bases and enclosingdams which are not impermeable, determined by calculation on the basis of the data of hydrogeologicalstudies. Water losses to seepage from spray pools and the water collecting tanks of towers are notconsidered in the calculation;

f) discharge of water from the system (blowdown), determined as a function of the quality of therecycled and added water, as well as water treatment methods.

Table 36Air temperature, °°°°C 0 10 20 30 40Value of Kevap for cooling towers and spraypools

0.001 0.0012 0.0014 0.0015 0.0016

Old data informationTable 37

Water temperature, °°°°C in river or canalflowing into reservoir (pond)

0 10 20 30 40

Value of Kevap for cooling reservoirs(ponds)

0.0007 0.0009 0.0011 0.0013 0.0015

Old data informationNotes: 1. For intermediate values of temperature, Kevap is determined by interpolation.2. Water lost to natural evaporation from cooling reservoirs (ponds) shall be determined on the basis of thestandards for the design of reservoirs.

Table 38Cooling unit Water loss P2 due to wind, % of cooling water

lossFan cooling towers with water trapping devices:

with no toxic substances in recycled water 0.1-0.2with toxic substances present 0.05

Chimney-type cooling towers without watertrapping devices; sprinkler heat exchange equipment

0.5-1

Chimney-type cooling towers with water trappingequipment

0.01-0.05

Open and spray towers 1-1.5Spray pools with throughput, m3/hr:

up to 500 2-3

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from 500 to 5000 1.5-2over 5000 0.75-1

Note: Lower values of losses shall be used for coolers with higher throughput, and also in calculations fortreatment of cooling water in order to prevent carbonate deposits.

PREVENTING MECHANICAL DEPOSITION

11.10. The possibility and rate of formation of mechanical deposits in the tanks of cooling towersand in heat exchange equipment shall be determined on the basis of the experience of operation ofcirculating water systems in the same region operating with water of the same source, or on the basis ofdata on the concentration and particle-size distribution (sinking velocity) of mechanical contaminants in thewater and air.

To prevent and remove mechanical deposits in heat exchange equipment, periodic water pulse orhydropneumatic cleanout shall be used in the process of operations, as well as partial clarification ofcirculating water.

11.11. The water of surface sources used for addition to a circulating water supply system shall beclarified in accordance with Section 6.

CONTROL OF “BLOOMING” OF WATER AND BIOLOGICAL OVERGROWTH

11.12. The control of water coloration in cooling reservoirs and ponds shall be undertaken inaccordance with the instructions of recommended Appendix 11 by spraying of a copper sulfate solutionover the surface of the water.

The use of copper sulfate shall be coordinated in each case with agencies of the sanitary-epidemiological service and fish stock protection agencies.

11.13. Circulating water shall be chlorinated in accordance with recommended Appendix 11 inorder to prevent the development of bacterial biological overgrowth in heat exchange equipment and pipes.The dose of chlorine shall be determined based on the experience of operation of water supply systemsusing water from the same source or on the basis of the chlorine absorption of the water added.

11.14. Chlorinators for treatment of cooling water and storage facilities shall be planned inaccordance with Section 6.

Reserve chlorinators need not be provided. The chlorine water from chlorinators shall be fed intothe cooled water receiving chamber.

With high chlorine absorption of the water and long pipelines in the circulating water system,chlorine water may be fed to several points in the system.

11.15. In order to prevent algae overgrowth of cooling towers, spray pools and sprinkler heatexchange equipment, periodic processing of the cooling water with a solution of copper sulfate shall beperformed in accordance with recommended Appendix 11. The concentration of the copper sulfate solutionin the dissolving tank shall be 2-4%.

11.16. To prevent biological overgrowth of cooling towers, spray pools and sprinkler coolers,additional periodic chlorination of water shall be performed upstream from these facilities in accordancewith recommended Appendix 11. Additional chlorine treatment of water shall be performed simultaneouslywith or following copper sulfate solution treatment.

11.17. Tanks, channels, pipes, equipment and valves which come in contact with the copper sulfatesolution shall be made of corrosion-resistant materials.

PREVENTING CARBONATE DEPOSITS

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11.18. The instructions of this Section extend to the design of circulating water supply systems forcooling of heat exchange equipment, machines and units in which the cooling water does not boil at thesurface of the heat exchanger and the heating of the water is to not over 60°C when fresh water sources andtreated wastewater are used.Note: Special requirements for cooling of water, heating of the water to over 60°C and local boiling on heatexchange surfaces require softening of the water added in ion exchange filters (sodium cationation orhydrogen cationation with “starvation” regeneration); the use of lime treatment and subsequent acidificationor phosphate treatment is permitted.

11.19. Treatment of water to prevent carbonate deposits shall be provided where Aadd⋅Ke ≥ 3 (Aadd

is the alkalinity of the water added, mg-eq/L, Ke is the concentration (evaporation) factor of salts which donot precipitate). The following methods shall be used to treat the water: acidification, recarbonation,phosphate treatment with polyphosphates and combined phosphate-acid treatment. It is permissible to useorganophosphorous compounds.

11.20. Methods of treating water to prevent carbonate deposits shall be employed as follows:acidification—with any value of alkalinity and total hardness of natural water and evaporation rate

of water in systems;phosphate treatment—with alkalinity of water added Aadd up to 5.5 mg-eq/L;combined phosphate-acid treatment of water—in cases when phosphate treatment does not prevent

carbonate deposits or the amount of blowdown is economically unsuitable;recarbonation with stack gases or gaseous carbon dioxide—with alkalinity of the water added up to

3.5 mg-eq/L and evaporation factors not exceeding 1.5.The dose of acid, carbon dioxide and phosphate reagents shall be determined in accordance with

recommended Appendix 12.

PREVENTING SULFATE DEPOSITS

11.21. To prevent calcium sulfate deposits the product of the active concentrations of

Ca and SO2+42−

ions in the circulating water shall not exceed the product of the solubility of

calcium sulfate (recommended Appendix 12).

11.22. To maintain the value of the product of active concentrations of the Ca and SO2+42−

ions within these limits, the corresponding evaporation rate of circulating water shall be maintained by

changing the blowdown of the system or partially reducing the concentration of Ca and SO2+42−

ions in the water added.11.23. To control sulfate deposits in circulating water supply systems, water shall be treated with

sodium tripolyphosphate in a dose of 10 mg/L as PO43-

or carboxymethylcellulose in a dose of 5 mg/L.

PREVENTING CORROSION

11.24. Treatment of water with inhibitors, protective coating and electrochemical protection shallbe used to prevent the corrosion of pipes and heat exchange equipment.

11.25. When inhibitors and protective coating are used in circulating water supply systems, heatexchange equipment and pipes shall be carefully cleansed of deposits and overgrowth.

11.26. Sodium tripolyphosphate, sodium hexametaphosphate and three-component compounds(sodium hexametaphosphate or tripolyphosphate, zinc sulfate and potassium bichromate), sodium silicate,etc. shall be used as inhibitors.

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The most effective type of corrosion inhibitor shall be determined in each specific case byexperimentation.Note: When justified, sodium nitrite and organophosphorous compounds may be used.

11.27. When sodium tripolyphosphate and hexametaphosphate are used to create a protectivephosphate film the concentration of inhibitors in the circulating water shall be 100 mg/L (as P2O5) for 2-3days, in water added to maintain the phosphate film—7-15 mg/L as P2O5. The rate of movement of thewater in heat exchange equipment shall be no less than 0.3 m/s.

11.28. When three-component inhibitor is used the dose of potassium bichromate shall be 2-4 mg/L

as CrO42-

, of zinc sulfate—1.5-3 mg/L as Zn2+ and sodium hexametaphosphate or tripolyphosphate—3-5

mg/L as PO43- .

The concentration of chromium in the body of water shall be determined when blowdown water isdumped, and the concentration in the air of the workplace shall be determined if water droplets fromcooling towers are carried by the wind. These concentrations shall not exceed the maximum permissibleconcentration (MPC).

The speed of movement of water in the system shall be no less than 0.5 m/s.11.29. When sodium silicate is used the dose of liquid glass as SiO2 shall be 10 mg/L; with high

concentrations of chlorides and sulfates (500 mg/L or more) the dose of SiO2 shall be increased to 30-40mg/L.

11.30. Protective coatings and electrochemical protection of pipes shall be planned in accordancewith Paragraphs 8.32-8.41.

COOLING OF RECYCLED WATER

11.31. The type and dimensions of coolers shall be determined considering:the design flow rate of water;the design temperature of the cooled water, the temperature drop of the water in the system and the

requirements of the process for stability of the cooling effect;the operating mode of the cooler (continuous or periodic);the design weather parameters;the conditions of placement of the cooling unit on the site, the nature of improvements in the

surrounding area, the permissible level of noise, influence of wind drift of water drops from coolingequipment on the environment;

the chemical composition of the recycled and added water, etc.11.32. The area of application of cooling units for water shall be taken as in Table 39.

Table 39Area of use of water cooling unit

Cooling unit Specific thermal load,thous. kcal/(m2/hr)

Water temperaturedrop, °°°°C

Temperature differenceof cooled water and airmeasured by wet-bulb

thermometer, °°°°CFan cooling towers 80-100 or more 3-20 4-5Chimney-type coolingtowers

60-100 5-15 8-10

Spray pools 5-20 5-10 10-12Cooling reservoirs 0.2-0.4 5-10 6-8Radiator (dry) towers — 5-10 20-35

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Open and spray units 7-15 5-10 10-12Note: Characteristics are given in the table for water arriving at the cooling unit with temperature not over 45°C.

11.33. Process design of cooling towers and spray pools shall be performed on the basis of themean daily air temperature as measured by wet- and dry-bulb thermometers (or relative humidity),measured at 7 a.m., 1 p.m. and 7 p.m. during the summer using multiple-year observations with 1-10%probability. For thermal and nuclear power plants, designs shall be based on the average daily airtemperature, as measured by wet- and dry-bulb thermometers during the summer season of an average anda hot year. The probability shall be selected depending on the category of water consumer as shown inTable 40.

Table 40Water consumer

categoryDeterioration of production process of

equipment operation resulting fromexcess of cooling water temperature over

design temperature

Probability of weatherparameters used to design

cooling unit, %

I Disruption of production process in generaland, as a result, significant losses

1

II Permissible temporary disruption ofprocess at individual units

5

III Temporary decrease in economiccharacteristics of production process as awhole and individual units

10

When data are not available on the average daily air temperature and humidity with the requiredprobability, average temperatures and humidities at 1 p.m. shall be used for the hottest month inaccordance with SNiP 2.01.01-82, adding 1-3°C to the wet-bulb air temperature for constant humiditydepending on the category of consumer.

11.34. Cooling tower process design shall be performed by the use of a method which considers theheat and mass transfer in the active cooling zone and the aerodynamic resistance of the cooling tower or byusing graphs composed on the basis of experiments.

11.35. Calculation of the cooling capacity of spray pools and open cooling towers shall be basedon experimental graphs.

11.36. Process design of radiator cooling towers shall be based on a method accepted for the designof heat-exchange equipment with finned tubing, cooled by air.

11.37. Process design of cooling reservoirs for thermal and nuclear power plants shall beperformed on the basis of the mean monthly hydrological and meteorological factors of an average yearconsidering the heat-accumulating capacity of the reservoir, equipment loading and repair schedules. Forthe summer period of an average and a hot year of probability 10% the power of the equipment shall beverified, limits set and the duration of limited power determined based on the maximum daily cooling watertemperatures. When the water of existing bodies of water is to be used for cooling, the specifics of thespatial formation of temperature mode under natural conditions and with the discharge of heated watershall be considered.

11.38. When circulating water contains impurities which are corrosive with respect to the materialsof cooling towers and spray pools, the water shall be treated or the facilities given protective coatings.

11.39. The depth of the water in spray pools and water collecting tanks of cooling towers shall betaken as no less than 1.7 m, the distance from the water level to the edge of the pool or tank—no less than0.3 m.

For towers located on the roofs of buildings, bases (pallets) with water depth of no less than0.15 m may be constructed.

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11.40. The water collecting tanks of cooling towers and spray pools shall be equipped withdischarge, drainage and overflow pipes, as well as maximum and minimum water level signaling devices.The delivery pipe shall be fitted with a trash screen with apertures of not over 30 mm.

The bottoms of water collecting tanks and spray pools shall have a slope of at least 0.01 in thedirection of the drainage pipe well.

11.41. The filling and output pipes of spray pools shall have valves to isolate the pools duringcleaning and repair operations.

11.42. Watertight coatings at least 2.5 m in width with a slope away from structures to assure thatwater carried away by the wind from open apertures in cooling towers and spray pools will be drainedoutward shall be provided around the water collecting tanks of towers and spray pools.

Cooling towers

11.43. Cooling towers shall be used in circulating water supply systems requiring consistent, deep coolingof water with high specific hydraulic and thermal loads.

When it is necessary to reduce the amount of construction, to regulate the temperature of thecooled water, to automate the process of maintaining the desired temperature of the cooled water orproduct, fan cooling towers shall be used.

In built-up areas, fan cooling towers on the roofs of buildings are preferred.In the southern regions, transverse-flow fan cooling towers may be used.In areas with limited water resources, and also to prevent contamination of circulating water with

toxic substances and protect the environment from their effects, the possibility shall be provided of usingradiator (dry) cooling towers or mixed (dry and fan) cooling towers.

11.44. In order to assure the greatest cooling effect of circulating water, cooling towers with filmwater flow shall be used.

When the circulating water contains grease, fat, resins and petroleum products, cooling towers withdrop sprinkling shall be used; when suspended substances which form deposits which cannot be washedaway by water are present, spray towers shall be used.

11.45. Sprinklers shall be provided in the form of modules, the design and arrangement of whichshall assure uniform distribution of water and air flow over the area of the cooling tower.

11.46. The water distribution system shall employ a pressurized tube, or channels may be used.When spray nozzles are used to form downward-directed spray, the distance from the nozzles to thesprinkler shall be 0.8-1 m, with upward-directed spray—0.3-0.5 m.

11.47. The location of nozzles on the pipes of the distributing system shall assure uniformdistribution of water over the area of the cooling tower above the sprinkler.

11.48. To prevent drops of water from being carried away from the cooling tower, wind barriersshall be installed in the area of the air distributor, and water-trapping devices above the water distributingsystem.

11.49. The design and placement of water-trapping devices shall assure that there are nopenetrating vertical slots (optical density) over the entire area of the cooling tower; water drops carriedaway shall not exceed 0.1-0.2% of the flow of circulating water containing no toxic substances, 0.05%—when toxic substances are present.

In fan cooling towers, water-trapping devices shall be placed at a distance of no less than 0.5 fandiameters from the fan impeller.

11.50. When cooling towers are located on building roofs, jalousies shall be provided on the airintake windows of the towers.

11.51. The design of the sheathing on a cooling tower frame shall prevent outside air from beingdrawn in.

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11.52. Fan cooling towers shall be sectional with air intake on two sides or single-section with airintake around the entire perimeter.

11.53. The area of cooling tower intake apertures shall be 34-45% of the area of the tower in plan.11.54. The shape of cooling towers in plan shall be: for sectional fan towers—square or

rectangular with a ratio of side lengths of not over 4:3, for single-section towers and chimney-typetowers—circular, polygonal or square.

11.55. To prevent icing of cooling towers in winter, the possibility shall be provided of increasingthe thermal and hydraulic load by disconnecting a portion of the sections or some towers, reducing the flowof cold air into the sprinkler.

11.56. To maintain the necessary cooled water temperature in winter, devices shall be provided todischarge warm water into the water collecting tank of the cooling tower.

11.57. The designs of cooling towers shall include:• a frame of reinforced concrete, steel or wood;• a sheath of wood, asbestos-cement or plastic sheets;• a sprinkler of wood, asbestos-cement or plastic;• water-trapping devices of wood, plastic or asbestos-cement;• water-collecting tanks of reinforced concrete.

Wooden structures shall be treated with nonwashable antiseptics, when softwood is used—modified (treated with special solutions).

Metal structures shall be protected by anticorrosion coatings in accordance with SNiP 2.03.11-85Reinforced concrete structures shall be made of concrete grades having the cold resistance and

water impermeability ratings given in Paragraph 14.24.

Cooling Reservoirs

11.58. Cooling reservoirs shall be used where there are moderate requirements for water coolingeffect, free, low-value land areas are available near enterprises, where there are natural bodies of water orartificial reservoirs.

11.59. The depth of cooling reservoirs at the summer water level shall be no less than 3.5 m over80% of the reservoir circulation zone. Measures shall be taken to eliminate shallow areas, to removefloating peat, and to assure the required water quality.

11.60. Dams, spillways, water outlets and channels for cooling reservoirs shall be designedaccording to standards documents for the design of water engineering structures.

11.61. Water management design of cooling reservoirs shall be performed in a manner similar tothe design of reservoirs considering the losses to additional evaporation.

11.62. The usage coefficients of cooling reservoirs shall be determined by analogy on the basis ofmodel laboratory studies, and when enterprises are expanded—on the basis of field investigations.

11.63. The location and design of water intake and outlet structures, as well as facilities to increasethe cooling of water (stream distributing structures, stream directing dams) shall be selected considering theinfluence of the wind, hydrologic specifics of bodies of water (discharge, wind, density and other currents),as well as the possibility of using and creating vertical circulation of the cooled water.

In order to reduce the temperature, increase the quality of water taken and protect young fish, thepossibility shall be considered of using deep water intakes.

11.64. For cooling reservoirs with influx of fresh water, a portion of the spent water shall bedischarged downstream in the reservoir.

11.65. When designing reservoirs, measures shall be provided to prepare their beds (removal oftrees, bushes, etc.). The composition and volume of measures shall be determined in each specific case.

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11.66. To prevent erosion of banks of a cooling reservoir and its silting, the following shall beprovided: reinforcement of banks, organization of surface water discharge, construction of dams at themouths of gullies, establishment of zones in which plowing, grass sowing and planting of bushes onreservoir slopes are forbidden.

11.67. With swampy territories adjacent to reservoirs, reclamation measures shall be performed.11.68. In order to reduce the concentration of salts in the water of reservoirs where necessary water

shall be discharged from the lower levels of the reservoir and fed in from other streams.

Spray Pools

11.69. Spray pools shall be used where the requirements for effective cooling of water are low andopen areas are available for the flow of air. They shall be placed with their long side perpendicular to thepredominant wind direction. When spray pools are planned, the possibility of forming fog and of icingneighboring structures and roads shall be considered.

11.70. Spray pools shall be planned in no less than two sections; one section is permitted forcirculating systems operating periodically.

11.71. The location of spray nozzles on the pipes of the distributing system shall support uniformdistribution of water over the area of the spray pool.

11.72. The width of a spray pool at the axes of the outermost nozzles shall be not over 50 m.To reduce the carrying of water drops with the wind the outermost nozzles shall be 7-10 m from

the edge of the pool depending on the pressure at the nozzle and the wind speed.11.73. In order to maintain the necessary temperature mode in winter, each section of a spray pool

shall be provided with a pipe for discharge of water without spraying.11.74. Spray pools shall be made of concrete or reinforced concrete slabs with a watertight shield.11.75. Spray devices may be placed over natural bodies of water. Leveling and securing of the

bank slope shall be done in such cases.

Placement of Cooling Units at Enterprise Sites

11.76. The placement of cooling units at the sites of enterprises shall be based on the condition ofassuring free access of air, as well as the shortest length of pipes and channels. The direction of the winterwind shall be considered to prevent freezing of ice on buildings and structures (for cooling towers andspray pools).

11.77. The minimum distance between water cooling units, buildings and structures, and alsobetween cooling units shall be determined in accordance with SNiP II-89-80.

12. EQUIPMENT, VALVES, AND PIPING

12.1. The instructions of this Section should be considered when determining room sizes, when installingprocess equipment, hoisting and transport equipment, and valves, and when laying piping in water supplybuildings and facilities.

12.2. When determining the area of production rooms, the width of passages should be adopted notless than:

between pumps or electric motors—1 m;between pumps or electric motors and a wall in subsurface rooms—0.7 m, and in others—1 m; in

this case the width of a passage next to an electric motor must be sufficient for dismantling of its rotor;between compressors or air pumps—1.5 m, and between them and a wall—1 m;between nonmoving protruding parts of equipment—0.7 m;

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in front of an electric distribution board—2 m.Notes: 1. When passages around equipment are regulated by the manufacturing plant, they should be

prescribed in accordance with technical specificaions.2. The following shall be permissible for units with a discharge pipe diameter up to 100 mm inclusively:

placement of units beside a wall or on brackets; placement of two units on one foundation with not less than 0.25m between protruding parts of the units and with passages not less than 0.7 m wide around paired units.

12.3. Hoisting and transport equipment must be foreseen in rooms to support operation of processequipment, valves, and piping. The following equipment should be prescribed as a rule in this case: forloads up to 5 metric ton—a hand hoist or a hand overhead track hoist; for loads over 5 metric ton—a handoverhead traveling crane; for loads raised to a height above 6 m or when the length of the crane track islonger than 18 m—electric crane equipment.

Notes: 1. Cranes needed only for installation of process equipment (pressure filters, hydraulic agitators,etc.) need not be foreseen.

2. Rigging may be used to move equipment and valves weighing up to 0.3 metric tons.12.4. An installation floor must be foreseen in rooms containing crane equipment.Equipment and valves should be delivered to the installation floor by rigging or a hoist travelling

on a monorail extending out of the building, and in justified cases, by transportation vehicles.A passage not less than 0.7 m wide must be provided around equipment or transportation vehicles

placed on an installation floor within the work zone of crane equipment.The dimensions of gates or doors should be determined on the basis of the overall dimensions of the

equipment or loaded transportation vehicles.12.5. The lifting capacity of crane equipment must be determined on the basis of the maximum

weight of the load or equipment to be moved, with regard for requirements of the equipment’smanufacturing plant on the conditions of its transportation.

If the manufacturing plant does not stipulate that equipment has to be transported fully assembled,the lifting capacity of the crane may be determined on the basis of the heaviest parts of the equipment.

Note: An increase in equipment weight and size must be accounted for when its replacement by equipmentof higher power is foreseen.

12.6. The height of rooms (from the elevation of the installation floor to the bottom of ceilingbeams) containing hoisting and transport equipment must be determined and cranes must be installed inaccordance with the “Regulations on Installation and Safe Operation of Cranes”.

In the absence of hoisting and transport equipment, room height should be prescribed per SNiP2.09.02-85.

12.7. When equipment, electric drives, and valve (gate) hand wheels requiring maintenance andcontrol are more than 1.4 m above the floor, platforms or catwalks should be foreseen; in this case themaintenance and control points must not be more than 1 m above the platform or catwalk.

The width of equipment foundations may be increased.12.8. Equipment and valves may be located beneath an installation floor or maintenance platforms

if the floor (or catwalk) is not less than 1.8 m above the bottom of protruding structures. In this case theremust be access holes or trapdoors on platforms above equipment and valves.

12.9. Remotely or automatically controlled valves (gates) on piping of any diameter must beelectrically driven. Pneumatic, hydraulic, or electromagnetic drives may be used.

In the absence of remote or automatic control, stop valves 400 mm or less in diameter should beequipped with manual drive, while those more than 400 mm in diameter should be equipped with electric orhydraulic drive; in certain cases when the justifications exist, hand-driven valves more than 400 mm indiameter shall be allowed.

12.10. Piping in buildings and facilities should be laid as a rule above the surface of the floor (onsupports or brackets), in which case catwalks should be installed above the pipelines and provision must bemade for access to and maintenance of equipment and valves.

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Piping may be laid in channels covered by removable slabs, or in basements.The dimensions of piping channels must be:for pipes up to 400 mm in diameter—the diameter plus 600 mm in width, and the diameter plus

400 mm in depth;for pipes 500 mm or more in diameter—the diameter plus 800 mm in width and the diameter plus

600 mm in depth.The channel must be widened in accordance with Paragraph 8.63 at the locations of flanged valves.The slope of the channel floor toward a drain hole should be not less than 0.005.12.11. Pressure piping and combined gravity-flow and pressure piping in buildings and on the

grounds of water pipeline facilities inside perimeter fencing must be made from steel pipe.The material of pipe used to transport corrosive liquids should be prescribed in accordance with

Section 6.

13. ELECTRICAL EQUIPMENT, PROCESS CONTROL, AUTOMATION, AND CONTROLSYSTEMS

General Instructions

13.1. The reliability categories of electric power supply to the load-using equipment of watersupply system facilities should be determined according to the “Regulations on Devices of ElectricalInstallations” (PUE) of the USSR Minenergo [Ministry of Power Engineering].

The dependability category of electric power supply to a pumping station must be the same as thecategory of the pumping station adopted in accordance with Paragraph 7.1.

13.2. The voltage of electric motors should be selected depending on their power and on theadopted power supply system, and with regard for future development of the planned facility; the design ofthe electric motors should be selected depending on the environment and the characteristics of the room inwhich the electrical equipment is to be placed.

Reactive power must be compensated by over-excitation of synchronous electric motors, and intheir absence, with the assistance of static compensating devices (condensers), and with regard for therequirements of the “Guidelines on Compensation of Reactive Power” of the USSR Minenergo.

13.3. Switch gear, transformer substations, and control panels should be located in built-in orattached rooms allowing for their possible expansion and increase in power. Separately standing enclosedswitch gear and transformer substations may be foreseen.

When enclosed panels are located in production rooms on balconies, measures must be taken tokeep water out of them.

13.4. Process control systems must foresee:resources and instruments for constant control;resources for periodic control (for adjustment of facilities and inspection of their work, and so on).13.5. Process control of water quality parameters must be accomplished by constant-control

instruments and analyzers, or by laboratory methods.13.6. Embedded parts, openings, chambers, and so on should be foreseen in structures of facilities

allowing for installation of electrical equipment and automation resources.13.7. Production process control systems and the volume of automation in facilities must be

adopted depending on operating conditions, they must be based on feasibility computations, and they mustaccount for social factors.

Water Intake Facilities for Surface and Underground Water

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13.8. When water intake facilities are fed by surface water, provisions must be made for control ofthe drop in water level across gratings and screens and for measurement of the water level in chambers andin the water basin or watercourse.

13.9. When water intake facilities are fed by underground water, provisions must be made formeasurement of flow rate or of the quantity of water delivered from each hole (shaft well), of the waterlevel in holes (wells) and in the collecting tank, and of pump pressure.

13.10. Provisions must be made in holes (wells) for automatic shutdown of pumps when the waterlevel falls below the permissible level.

13.11. Pumps used in water intake facilities fed by underground water must be controlledautomatically depending on the water level in the water tower (collecting tank), or remotely(telemechanically) from a control station.

Pumping Stations

13.12. Provisions must be made in pumping stations for measurement of pressure in pressuretunnels and at each pumping unit and of the flow rate of water in pressure tunnels, and for control of thewater level in drain pits and vacuum boilers, of the temperature of machine units bearings (whennecessary), and of the flooding danger level (a water level in a machine room even with the foundations ofelectric drives). If the power of the pumping unit is 100 kW or more, periodic determination of efficiencywith an error of not more than 3 percent must be provided for.

13.13. Pumping stations of all purposes must be planned as a rule to be controlled without constantattendance by service personnel: automatically—depending on process parameters (the water level inimpoundment facilities, the pressure or flow rate of water in the network); by remote (telemechanical)control—from a control station; local control—by periodically visiting personnel, with transmission of thenecessary signals to a control station or a station constantly manned by service personnel.

Automatic or remote (telemechanical) control must also be supplemented by local control.13.14. The possibility for adjusting water pressure and flow rate to ensure minimum consumption

of electric power must be provided for in pumping stations experiencing a variable work load. Suchadjustment may be accomplished in steps—by changing the number of working pumping units, orgradually—by changing pump rpm or the degree to which adjusting valves are opened, and by other means,as well as by a combination of these means.

13.15. One pumping unit in a group of 2-3 working units must be equipped with an adjustableelectric drive as a rule.

As a rule, an adjustable electric drive should be controlled automatically depending on the pressureat control points in the network, the flow rate of water delivered to the network, and the water level inreservoirs.

13.16. Synchronous electric motors should be prescribed for pumping units with a power of 250kW or more, while asynchronous squirrel-cage electric motors should be adopted for units of lower power.Asynchronous wound-rotor electric motors should be used with pumping units operating as anasynchronous gated cascade.

13.17. Upon emergency disconnect of working pumping units in automated pumping stations, abackup unit should switch on automatically.

In telemechanical pumping stations, automatic switch-on of a backup unit must be designed intocategory I pumping stations.

13.18. Self-starting of pumping units, or their automatic switch-on after a certain time intervalwhen simultaneous self-starting is impossible due to power supply conditions, should be provided for incategory I pumping stations.

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13.19. When a vacuum boiler is installed in a pumping station for pump priming, the vacuumpumps must be designed to work automatically depending on the water level in the boiler.

13.20. A blocking system should be designed into pumping stations to preclude consumption of thevolume of water in reservoirs reserved for fire and emergency use.

13.21. Fire pumps should be remote-controlled, in which case the blocking system preventingconsumption of the volume of water reserved for fire must be deactivated automatically and flushing pumps(if they are present) must be switched off simultaneously with activation of a fire pump. Simultaneouslywith activation of fire pumps in a high-pressure fire suppression system, all pumps intended for otherpurposes should switch off automatically and gate valves on the supply pipeline leading to the water toweror to pressure reservoirs should close.13.22. Vacuum pumps in pumping stations employing siphoned water intake must operate automaticallydepending on the water level in the air dome installed on the siphon line.

13.23. The following auxiliary processes should be automated in pumping stations: flushing ofrevolving screens according to a prescribed program, regulated in relation to time or a difference in levels,evacuation of drain water depending on the water level in the drain, electric heating depending on theinterior air temperature, and ventilation in accordance with SNiP 2.04.05-91.

Water Treatment Plants

13.24. The following should be monitored in water treatment plants:• the flow rate of water (untreated, treated, flushing, and recycled);• the flow rate of reagent solutions and air;• the water levels in filters, agitators, reagent tanks, and other containers;• sediment levels in settling tanks and clarifiers;• the water flow rate and the head loss in filters (when necessary);• the amount of residual chlorine or ozone;• the pH of untreated and treated water;• the concentrations of reagent solutions (measurements may be made with portable instruments

and in the laboratory);• other process parameters which require regular monitoring and for which the appropriate

technical resources are installed.13.25. The following should be automated:• metering of coagulants and other reagents;• decontamination with chlorine, ozone, and chlorine-containing reagents;• fluorination and defluorination by the reagent method.When the water flow rate is variable, automatic metering of reagent solutions must occur in

relation to the flow rates of the water to be treated and of reagent at a constant concentration, coupled withlocal or remote adjustment of this ratio, and when the grounds for doing so exist, on the basis of thequalitative indicators of untreated water and reagents.

13.26. The filtering rate in filters and contact clarifiers must be adjustable in relation to the waterflow rate or the water level in filters, and water must be distributed between them uniformly.

13.27. Flushing of filters and contact clarifiers (in a quantity of more than 10) should beautomated.

Filters should be taken offline for flushing depending on the water level, the loss of head in thefilter medium, or the quality of the filtrate; contact clarifiers should be taken offline for flushing dependingon the loss of head or the decrease in flow rate when adjusting valves are completely open.

13.28. Automatic removal of air from piping supplying flushing water must be foreseen at thefilters.

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13.29. Drum screens and microfilters should be flushed automatically according to a prescribedprogram or on the basis of the difference in water levels.

13.30. Pumps transferring reagent solutions must be controlled locally, and they must disconnectautomatically at set levels of solutions in tanks.

13.31. Metering of reagents with respect to pH and conductance should be automated in reagentwater-softening units.

Metering of reagents (lime, soda, flue gases) with respect to pH, conductivity, etc. should beautomated in units used to eliminate carbonate hardness and to recarbonate water.

13.32. Regeneration of ion-exchange filters should be automated: cationite—with respect toresidual water hardness; anionite—with respect to conductance of treated water.

Water Conduits and Water Pipeline Networks

13.33. Emergency warning devices should be designed into water conduits.13.34. Instruments measuring pressure, and the water flow rate when necessary, and transmitting

information on prescribed parameters must be installed at monitoring points in the lines of water pipelinenetworks.

13.35. When adjustment of water flow rates is necessary, installation of wicket gates in thenetwork controlled remotely or telemechanically from a control station should be foreseen.

Water Storage Impoundment Facilities

13.36. To support operation of automatic systems and transmission of signals to a pumping stationor a control station, measurement of water levels and their monitoring (when necessary) must be foreseen inall kinds of reservoirs and tanks.

Circulating Water Supply Systems

13.37. Besides the requirements of Paragraph 13.12, monitoring of the following must be foreseenin circulating water supply systems:

the flow rate of added water;the levels in heated and cooled water in chambers;the temperatures of heated and cooled water;the pH of cooled water;the concentration of residual chlorine in cooled water;the concentration of salts in heated water.13.38. Control of circulating water supply pumping stations must be in accordance with items

13.13-13.19.13.39. Connection and disconnection of heated-water pumps should be automated depending on the

water level in the inlet chamber.13.40. Automatic regulation of supply of added water to the circulating system must be based on

the level in the cooled-water chamber.13.41. Change in the number of working fans depending on the temperature of cooled water must

be foreseen in cell-type cooling towers: at automated pumping stations—by automatic resources, and at allothers—from a control station by remote (telemechanical) control resources.

13.42. Metering of the following solutions must be automated for stabilized water treatment:phosphates—with respect to the flow rate of added water;acids—with respect to a prescribed pH;

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chlorine and vitriol—in accordance with a prescribed program.

Control Systems

13.43. A centralized system for controlling water pipeline facilities should be foreseen as a rule inorder to ensure delivery of water of required quality to consumers in the needed quantity.

13.44. Process control systems should be:under supervisory control—a system permitting monitoring and maintenance of prescribed working

conditions of water pipeline facilities, based on the use of information monitoring, transmission,conversion, and display resources;

automated (ASU TP [Automated Production Process Control System])—a supervisory controlsystem in which computers assess the economic effectiveness and quality of work and calculate optimumoperating conditions for facilities.

ASU TPs should be used on the condition that their cost is recoupable.13.45. Supervisory control must have a one-stage structure with a single control station. A two- or

multi-staged supervisory control structure with central and local control stations shall be permitted in largewater supply systems with a large quantity of facilities located at different sites. The need for such astructure must be justified in each case.

13.46. Supervisory control of a water supply system must be part and parcel of the supervisorycontrol system of an industrial enterprise’s power facilities or of the supervisory control system of apopulation center’s municipal management system.

A water supply system’s control station must be operationally subordinated to the industrialenterprise’s or population center’s control station.

Control of a water supply system may be accomplished from a control station used jointly by anindustrial enterprise and a municipal management system, on the condition that this station is fitted out withindependent instrument boards and water supply system control consoles.

13.47. Supervisory control must be combined with partial or complete automation of the monitoredfacilities. The extent of supervisory control must be minimized, but adequate to provide exhaustiveinformation on occurring processes and on the state of process equipment, as well as for effectiveoperational control of facilities.

13.48. Installation of operator stations subordinated to the supervisory control service shall bepermitted at facilities not fully equipped with automation resources and requiring constant manning by dutypersonnel for local control and monitoring.

13.49. A water supply system’s supervisory control system must be supported with directtelephone communication from the control station to monitored facilities, to various facility operatingservices, to the power system controller, to the water pipeline management administration, and tofirefighting services.

Control stations and individual monitored facilities must also be included in the system ofadministrative and maintenance telephone communication.

Control stations and monitored facilities must be radio-equipped, and as a rule, fitted out withinstruments and devices monitoring hourly flow rate.

13.50. The following should be designed into control stations:• a control room—to accommodate control personnel, consoles, signal panels, and other

information display and communication resources;• an instrument room—to accommodate the equipment of telemechanical and power supply

systems and the communication line switching equipment (distribution frames) of channelingand relay telephone equipment;

• a break room;

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• a shop for routine repair of equipment;• a storage battery and charging room.• The following must be foreseen additionally to accommodate the special equipment of a

SCADA:• a computer room;• premises for data preparation and storage;• a room for programmers and operators.Individual rooms may be combined or excluded depending on the composition of the equipment

foreseen for the control systems.13.51. The control stations of water supply systems should be located at the sites of water pipeline

facilities, in administration and general service buildings, in filter or pumping station buildings (givenestablishment of the necessary conditions in terms of noise, vibrations, etc.), and in water pipeline facilitycontrol buildings.

13.52. Supervisory control must be foreseen in telemechanical control systems:• for non-automated pumping units requiring operational intervention by a controller;• for automated pumping units in stations at which interruptions in water supply cannot be

tolerated and which require redundant control;• for fire pumping units;• for gate valves in networks and water conduits to permit prompt switching.13.53. When supervisory control is enhanced by a telemechanical system, provisions must be made

for transmission of measurements of the main process parameters of water delivery, distribution, andtreatment to control stations.

In certain cases the system’s function may be limited to just annunciation of parameters.13.54. Annunciation of the following must be foreseen when dispatcher control is telemechanized:• the condition of all remote-controlled pumping units and gates and of mechanisms under local

or automatic control in order to keep the controller informed;• emergency disconnection of equipment;• flooding of the station;• general caution and general emergency warning signals for each facility or process line;• the characteristic and maximum permissible values of process parameters;• alarms (activated when doors and hatches are opened) at unsecured facilities;• fire danger.13.55. The control system designed into an ASU TP must carry out information, computation, and

control functions.

14. STRUCTURAL CONCEPTS AND STRUCTURES OF BUILDINGS AND FACILITIES

The Master Plan

14.1. Sites for construction of water pipeline facilities must be selected and their territory must belaid out and built up in accordance with process requirements stated in SNiP II-89-80 and the requirementsof Sections 10 and 11.

14.2. The layout marks on the sites of water pipeline facilities situated on the banks ofwatercourses and water basins must be located not less than 0.5 m above the theoretical maximum waterlevel as determined from Table 11, with regard for wind-driven wave surges and the elevation reached bywind waves on the slope, as determined in accordance with SNiP 2.06.04-82.

14.3. Storehouses for temporary storage of strong-acting toxic materials (SDYaV) on the site of awater pipeline facility must be located not less than 30 m away from constantly manned buildings and

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facilities (having no relationship to storage) and from water basins and watercourses; in accordance withSNiP II-89-80 from buildings that are not constantly manned; not less than 300 m from residential, public,and production buildings (away from the site) when storing SDYaV in permanently installed containers(tanks), and not less than 100 m from the former when they are stored in containers or cylinders.

14.4. Water pipeline facilities must be fenced. Solid fencing 2.5 m high must be installed as a rulearound the sites of water treatment and pumping stations, reservoirs, and water towers ringed by the firstbelt of a sanitary protection zone. The fencing may be solid to a height of 2 m and topped with 0.5 m ofbarbed wire or chain-link fencing, in which case the barbed wire must consist of 4-5 strands secured tobrackets on the inside surface of the fence in all instances.

Structures other than gatehouses and administration and general service buildings may not abut onfencing.

The type of fencing around the sites of underground and surface water intake facilities, pumpingstations used for initial lifting and transfer of untreated water, and the sites of domestic and drinking waterpipeline facilities located on fenced and guarded grounds of enterprises shall be prescribed with regard forlocal conditions and the requirements of the “Instructions on Planning Enclosures Around the Sites ofEnterprises, Buildings, and Facilities, and Parts Thereof” (SN 441-72).

Note: Fencing need not be installed around pumping stations at places where the flow of water is notinterrupted (in the absence of reservoirs), around water towers with a solid trunk situated on the grounds ofenterprises or population centers, and around the sludge collectors of water treatment plants.

14.5. The following technical security resources must be foreseen on the sites of water pipelinefacilities ringed by the first belt of a sanitary protection zone:

• a prohibited zone 5-10 m wide along the inside of the fencing of a site enclosed by barbed orsmooth wire to a height of 1.2 m;

• a guard path inside the prohibited zone 1 m wide located 1 m from the fencing of the prohibitedzone;

• signposts marking the boundaries of the prohibited zone and installed at intervals of not morethan 50 m;

• security lighting along the fencing perimeter, with the light fixtures installed above the fencingso as to illuminate the approaches to the fencing, the fencing itself, and the prohibited zone asfar as the guard path;

• a telephone communication post system and two-way electric warning bell posts, together witha control station or guard room, which should be foreseen as necessary along category I waterpipelines (Paragraph 4.4).

The entire volume of technical security resources must be provided to the sites of water treatmentplants ringed by the first belt of a sanitary protection zone; the fencing around the sites of water treatmentplants equipped with pressure filters, pumping stations, reservoirs, and water towers must be fitted out inaccordance with Paragraph 14.4, and with security lighting; the sites of underground and surface waterintake facilities and primary pumping stations and the sites of water treatment plants, pumping stations,reservoirs, and water towers located at enterprises with grounds that are fenced and guarded must be fencedas set forth in Paragraph 14.4.

14.6. Improved approach roads and through roads must be foreseen to buildings and water pipelinefacilities located away from population centers and enterprises, and within the first belt of the sanitaryprotection zone of underground water intakes.

Space-Planning Concepts

14.7. Space-planning and design features of water supply buildings and facilities must be employedin accordance with SNiP 2.09.05-85, SNiP 2.09.04-87, and SniP 2.01.02-85.

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14.8. Grouping of impoundment facilities and premises connected by a common productionprocess should be foreseen as a rule when planning water treatment plants.

14.9. The essentiality class and the fire resistance class of buildings and facilities must be adoptedin accordance with Table 41.

In terms of degree of fire danger, water supply buildings and structures should be classified ascategory D production operations, and carbonization departments and ammonia facilities should beclassified as category C production operations.

14.10. Production process sanitation characteristic groups and data to be used in designing heating,ventilation, and lighting of buildings and rooms should be taken from Table 44.

14.11. The dimensions of impoundment facilities that are rectangular in plan view and thediameters of impoundment facilities that are round in plan view must be adopted as multiples of 3 m, andtheir height as multiples of 0.6 m. When the length of a side or the diameter of a facility is up to 9 m, and inthe case of impoundment facilities built into buildings (regardless of their dimensions), the dimensions ofrectangular facilities may be adopted as multiples of 1.5 m, and those of round impoundment facilities maybe adopted as multiples of 1 m.

Table 41Facility Facility Category by

Water AvailabilityMargin Per

Paragraph 4.4

Essentiality Class ofBuildings, Facilities,

and Structures

Degree of FireResistance

1. Water intakes IIIIII

IIIII

IIIIIIV

2. Pumping stations IIIIII

IIIIII

IIIIII

3. Water treatment plants II II II-III4. Separately standing chlorinating plants I II II5. Water-storage impoundmentsnumbering:up to 2, or if water reserved for fire ispresentover 2, or in absence of water reserved forfire

I

II

II

II

Notstandardized

As above

6. Water conduits I-III I-III As above7. Water pipeline networks, wells III III As above8. Water towers III II II9. Circulating water coolers:cooling towersspray ponds

IIII

IIII

II-VNot

standardized10. Reagent preparation departments,storerooms

II II II

11. Spaces for electrical devices oftransformer rooms, switchgear, completetransformer substation, distribution panelrooms, control rooms

III II II

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Facility Facility Category byWater Availability

Margin PerParagraph 4.4

Essentiality Class ofBuildings, Facilities,

and Structures

Degree of FireResistance

Note: Auxiliary buildings and amenity rooms should be classified as essentiality class II and fire resistance degreeII.

14.12. Subsurface impoundment facilities banked with dirt to a height of less than 0.5 m above thegraded surface of the grounds must be fenced to prevent their being hit by transportation or machinery.

14.13. Open impoundment facilities must have additional fencing along their outer perimeter iftheir walls rise less than 0.75 m above the elevation of the floor, pad, or grading elevation, in which casethe total height to the top of the fencing must be not less than 0.75 m. Walls more than 300 mm wide intheir upper section may rise above the floor, pad, or grading elevation not less than 0.6 m without fencing.The floor or grading elevation must be not less than 0.15 m below the top of the walls of openimpoundment facilities.

14.14. The enclosing and load-bearing structures of buildings may abut on the walls of built-inimpoundment facilities not intended for storage of corrosive liquids.

14.15. Stairs leading out of subsurface rooms must be not less than 0.9 m wide with a pitch of notmore than 45°, while those leading from rooms up to 12 m long must have a pitch of not more than 60°.The width of stairs leading to service platforms must be not less than 0.7 m, and their pitch must not bemore than 60°.

Stairs 0.5 m wide with a pitch of more than 60° or ladders may be used for isolated crossings overpipes and to reach individual valves and gates.

14.16. The bottoms of manholes, drain holes, and impoundment facilities up to 10 m deep may beaccessed by foot brackets or vertical ladders. In this case safety enclosures must be provided on laddersmore than 4 m high. Safety enclosures need not be foreseen in manholes.

14.17. The internal trim of rooms must be in accordance with the recommendations of Appendix13.

Structures and Materials

14.18. Impoundment facilities must be planned as a rule out of monolithic prefabricated reinforcedconcrete. When there are grounds for doing so, other materials may be used if they ensure the requiredoperating qualities of the facilities. The walls of reinforced concrete cylindrical impoundment facilitiesmore than 9 m in diameter should be pre-stressed as a rule.

Steel or local noncombustible materials may be used for the trunks of water towers, while steelmay be used for tanks.

Use of steel for reservoirs is not permitted except in regions stipulated in TP 101-81*.14.19. Expansion joints and shrinkage strips need not be foreseen in impoundment facilities up to

50 m long located in unheated buildings or in the open, and in impoundment facilities up to 70 m longwhich are located in heated buildings or are completely banked, on the condition that the ambient airtemperature of the coldest day is not less than minus 40°C and the water temperature in the container doesnot exceed 40°C.

In this case impoundment facilities respectively more than 25 and 40 m long require installation ofone or two temporary joints 0.5-1 m wide to be filled in at a positive temperature during the coldest time ofthe construction period; the bottom should be poured between these joints continuously.

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14.20. The tightness of enclosing structures of subsurface parts of buildings must be such thatplaces of moisture accumulation (without formation of water droplets) occupy an area of not more than 20percent of the inside surface of the enclosing structures.

The enclosing structures of impoundment facilities must satisfy requirements imposed on hydraulictesting of these facilities.

Enclosing structures of drinking-water reservoirs must also totally preclude entry of atmosphericand groundwater and dust into the reservoir.

14.21. Warmth retention must be designed into walls and covers of covered impoundment facilitiesdepending on the climatic conditions, the temperature of the entering water, and the conditions under whichthey must operate.

Warmth retention should be accomplished as a rule by applying dirt, in which case the thickness ofthe dirt layer on the cover of a container must be not less than 0.5 m. Synthetic warmth-containingmaterials may be employed.

Measures must be foreseen to prevent freezing of dirt supporting impoundment facility floors whenthe container is emptied in winter, and during construction.

14.22. The interior surfaces of concrete and reinforced concrete structures coming in contact withwater in reservoirs intended for storage of drinking water must meet the requirements of not less thancategory A1 per GOST 13015-75, revised.

14.23. When planning contact clarifiers to be used in treating water for domestic and drinkingneeds, glass partitions rising not less than 2.5 m from the floor of service platforms separating the clarifiersfrom the control corridor must be foreseen; in this case the lower part of the partition must be solid to aheight of 1-1.2 m.

Concrete of not less than class V25 should be used for the floors of contact clarifiers devoid ofsupporting layers.

14.24. The brand of concrete must satisfy the requirements of Table 42 in relation to frostresistance and water tightness for reinforced concrete structures of impoundment facilities and coolingtowers.

Table 42Structures and the Conditions of Their

OperationRequired Brand of Concrete

With Respect to Frost Resistance at a TheoreticalAmbient Air Temperature of

With Respectto WaterTightness

Minus 5°Cand Higher

BelowMinus 5°Cto Minus

20°C

BelowMinus 20°C

to Minus40°C

BelowMinus 40°C

I. Impoundment Facilities1. Structures subjected to alternating periodsof freezing with a variable water level andwith constant exposure to the airenvironment:

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Structures and the Conditions of TheirOperation

Required Brand of Concrete

With Respect to Frost Resistance at a TheoreticalAmbient Air Temperature of

With Respectto WaterTightness

Minus 5°Cand Higher

BelowMinus 5°Cto Minus

20°C

BelowMinus 20°C

to Minus40°C

BelowMinus 40°C

a) thin-walled structures such as channels Mrz150

Mrz200

Mrz300

Mrz400

At pressuregradients of:up to 30—

V4; from 30to 50—V6;

over 50—V8b) other structures of open-air facilities (thefacing of water basin slopes and waterintake facilities)

Mrz100

Mrz150

Mrz200

Mrz300

As above

2. As above, with a constant water level (thewalls of open-air impoundment facilities)

Mrz75

Mrz100

Mrz150

Mrz200

As above

3. Structures buried in the ground or coveredwith dirt and located in a zone of seasonalfreezing (enclosing structures ofimpoundments and manholes).

Mrz50

Mrz75

Mrz100

Mrz150

As above

4. Structures located in heated rooms(filters, clarifiers, reagent tanks), thoseconstantly under water (water intakes, thefloors of impoundment facilities) or thoseburied beneath the freezing depth

- - Mrz50

Mrz75

As above

II. Cooling towers5. Surface structures (except stacks) and thewalls of catchment basins when the thermalload in winter per square meter of irrigationarea is 50,000 kcal/hr or more

Mrz100

Mrz200

Mrz300

Mrz400

V8

6. As above, with a thermal load less than50,000 kcal/hr

Mrz200

Mrz300

Mrz400

Mrz400

V8

7. Stacks Mrz300

Mrz400

Not used V8

8. The floor of water catchment basins witha thermal load per square meter of irrigatedarea of 50,000 kcal/hr or more

Mrz50

Mrz100

Mrz150

Mrz200

V6

9. As above, with a thermal load less than50,000 kcal/hr

Mrz100

Mrz150

Mrz200

Mrz300

For temper-atures down

to minus40°C—V6;

below minus40°C—V8

Notes: 1. Concrete brands with respect to frost resistance are given for facilities in essentiality class II. In the case of class Ifacilities, the brands of concrete with respect to frost resistance must be increased by one step, and in the case of class IIIfacilities they should be decreased by one step, but not below Mrz 50.2. When corrosive media are present, brands of concrete with respect to water tightness should be designated with regardfor requirements of SNiP 2.03.11-85.3. The requirements on hydraulic engineering concrete do not apply to water supply impoundment facilities.4. The pressure gradient is defined as the ratio of hydrostatic pressure to the thickness of the structure.

14.25. Piping going through enclosing structures of impoundment facilities and throughunderground parts of buildings must be caulked to make the enclosing structures watertight.

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When pipes are caulked with rigid sealing material, the possibility of forces being transferred fromthem to enclosing structures must be accounted for and steps must be taken to exclude or reduce theseforces; when glands are used, access must be provided to them for inspection and for renewal of packingmaterial.

In all cases of sealing off pipelines, measures must be foreseen to ensure the integrity of equipmentand enclosing structures coming in contact with them in the face of temperature and seismic effects and ofthe difference in settling of buildings or facilities and exterior pipelines.Note: Passage of pipes through a floor is permitted using ribbed steel connecting pipes rigidly secured to thefloor, and with concrete poured around the section of the pipeline beneath the floor.

14.26. Hydraulic testing of impoundment facilities for strength and water tightness in accordancewith SNiP 3.05.04-85 must be carried out at a positive temperature of the surface of exterior walls, inwhich case facilities with an anticorrosion lining must be tested before the lining is applied.

Drinking water reservoirs must be tested additionally for the water tightness of all enclosingstructures.

14.27. The height of backfill from the top of manhole covers to the backfill surface must bedetermined with regard for vertical layout, and adopted at not less than 0.5 m.

Aprons 0.5 m wide sloping down from the hatches of manholes located on unpaved built-up landmust be foreseen around the hatches. Hatch covers on roadways with an improved surface must be evenwith the surface of the roadway.

The hatch covers of manholes on water conduits laid through undeveloped territory must be notless than 0.2 m above the ground surface.

Structural Design

14.28. When designing impoundment facilities and the subsurface portions of buildings, the loads,effects and overloading coefficients must be adopted in accordance with SNiP 2.01.07-85 and Table 43,and the essentiality class should be adopted in accordance with Table 41.

14.29. Impoundment facilities must be designed for loads and effects with regard for the overloadcoefficients in Table 43, for two combinations of loads:

I—in hydraulic tests, when the buried facility is filled with water with the most disadvantageoussection-by-section filling. For unbanked facilities, this would be the operational combination;

II—in operation, when the facility is not filled with water and banked with dirt. In this caseresistance to floating must be tested.

Table 43Loads and Effects Over-

loadCoef-ficient

Buried or Embanked Facilities Impound-mentFacilitiesInsideBuildings

Impoundment Facilities Sub-surfaceParts of

BuildingsCovered Open

Load CombinationsI II I II I II I II

ConstantBackfill pressure 1.15 - + - + - + - -Weight of cushioning layer 1.15 - + - - - - - -

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Loads and Effects Over-load

Coef-ficient

Buried or Embanked Facilities Impound-mentFacilitiesInsideBuildings

Impoundment Facilities Sub-surfaceParts of

BuildingsCovered Open

Load CombinationsI II I II I II I II

Weight of structure itself 1.1(0.9)

+ + + + - + + +

Temporary Long-TermPressure of process fluid 1 - See note

2- See note

2- - - +

Groundwater pressure 1.1 - + - + - + - -Temperature effects from process fluid 1.2 - + - + - - - +Short-TermLoads on prism of collapse of backfill atthe base of an embankment, based onactual data but not less than 10 MPa(1,000 kgf/m2) [sic]

1.3 - + - + - + - -

Water pressure in hydraulic testing 1 + - + - - - + -Load on surface material andembankments, including the temporaryload or vacuum arising when the facilityis emptied, and a snow load, not morethan 2.5 MPa (250 kgf/m2) [sic]

1.2 - + - - - - - -

Vacuum arising upon emptying ofcovered containers, on the basis of actualdata but not more than 0.1 MPa (100kgf/m2) [sic]

1.1 - + - - - - - -

Notes: 1. A "plus" sign means presence of a load or an effect with this combination.2. Water pressure on enclosing structures is accounted for in hydraulic testing as a temporary short-term load.The pressure of process fluid on exterior walls during operation should be accounted for as temporary long-termpressure, in which case the combination with simultaneous pressure from the cushioning layer must be accountedfor in relation to buried facilities. Pressure on interior walls of multi-sectional impoundment facilities must beaccounted for as a temporary short-term load if during operation of these facilities adjacent sections will beemptied for short periods of time.3. The standard load on the walls and floors of impoundment facilities from the pressure of process fluid (orwater in hydraulic tests) must be adopted equal to the hydrostatic pressure of the fluid at the maximum designlevel. The theoretical load must be adopted equal to the hydrostatic pressure of the fluid when the level of thefluid is 100 mm above the lip of the overflow, and in its absence, when it is at the top of the walls.4. When facilities are filled with fluid having a temperature above 50°C or when the temperature difference isgreater than 30°, their structures must be designed for temperature effects.5. Material covering buried or embanked impoundment facilities must be designed for the short-term loads ofconstruction machinery traveling over a dirt layer not less than 0.3 m thick, without regard for other temporaryloads.6. Components of the covering material must be designed for eccentric tension arising during operation from thepressure of process fluid in the container using the maximum possible load on the covering material and pressureexerted on the wall by dirt with an overload coefficient of 0.9 and with an angle of internal friction with acoefficient of 1.1.7. Partitions not designed to withstand hydrostatic pressure must be tested for wind loads experienced when openimpoundment facilities are emptied or during construction of covered impoundment facilities.

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14.30. The theoretical groundwater levels at the sites of water pipeline facilities must beestablished in accordance with a long-term prediction with regard for the maximum water level in thewatercourse or water basin, depending on the water availability margin taken from Table 11. The strengthand stability of buildings and facilities situated in the floodplains of watercourses and water basins must bechecked during construction at the water level computed for a water availability margin of 10 percent.

14.31. Impoundment facilities may be designed to resist floating without regard for temporaryrising of groundwater during floods, if the plans foresee measures to prevent emptying of the facilities insuch periods, and monitoring of the level of ground water.

The coefficient of resistance to floating should be adopted equal to 1.1.14.32. After cylindrical impoundment facilities are filled with water, the compression stresses in

the concrete of their walls resulting from pre-stressing must be, in the absence of a cushioning layer andwith regard for all losses in stressed valves, not less than 0.08 MPa (8 kgf/cm2) in the lower section equalto one-third of the height, and 0.05 MPa (5 kgf/cm2) in the upper section.

Anticorrosion Protection of Structural Members

14.33. Anticorrosion protection must be provided to structural members in accordance with SNiP2.03.11-85 and Paragraph 1.3.

14.34. When planning underground and surface facilities located within range of stray currents,measured to protect reinforced concrete structures from electrochemical corrosion must be foreseen.

14.35. The possibility must be foreseen for applying and periodically restoring an anticorrosioncoat on structural elements, or design features ensuring integrity of facilities during the entire period ofoperation must be adopted.

14.36. When planning containers for storage of corrosive liquids, a possibility should be foreseenfor regular observation of the condition of exterior surfaces of walls and for checking the tightness of thefloor.

The following shall not be permitted:abutment of load-bearing walls of buildings on the walls of containers;abutment of ceiling-floors and columns on the walls or floors of containers;installation of dividing partitions inside containers for storage of different liquids;laying of piping within the substance of floor concrete;disturbance of the integrity of anticorrosion linings.Note: In cases when access to structural components of containers for regular inspection is provided and

the possibility exists for periodic restoration of anticorrosion linings and for repair of structures, maintenanceplatforms and enclosing structures in rooms housing pumps used to transfer liquids out of these containers mayabut on the walls of the containers.

Heating and Ventilation

14.37. The necessary air exchange in production rooms should be computed in relation to the quantity oftoxic discharges from open impoundment facilities, equipment, valves, and utilities. The quantity of toxicdischarges must be adopted on the basis of data from the section of the plan describing productionconditions.

In the absence of data, the results of full-scale tests on analogous operating facilities should beused. When there are no analogues for particular facilities, the air quantity may be computed on the basisof the frequency of air exchange using Table 44.

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Table 44Facilities and Rooms Air

Temper-ature forHeatingSystems,

°C

Air ExchangeFrequency, hr

ProductionProcess

SanitationCharacter-

istics Group

StandardizedCoefficient of

NaturalIllumination

(KYeO) WithSide Lighting

Illumina-ion WithArtificialLighting ,

Lx

Intake Exhaust1. Machine rooms of waterintake facilities

5 1 1 I-b 0.3 75

2. Machine rooms of pumpingstations

5 Based oncomputations

allowing for heatevolution

I-b 0.3 75

3. Water treatment plant:a) drum screen and microfilterdepartment

5 Based oncomputationsallowing for

moisture evolution

I-b 0.3 75

b) filter room 5 As above I-b 0.3 75c) chlorine metering room;ozonation unit

16 6 6 II-c 0.3 75

d) ammonia metering unit 16 6 6 II-c 0.3 754. Reagent managementdepartments supportingpreparation of solutions of:a) aluminum sulfide, lime milk,hexametaphosphate, sodiumfluoride, polyacrylamide, activesilicic acid

16 3 3 II-c 0.3 75

b) iron chloride, hypochlorite 16 6 6 II-c 0.3 755. Reagent storehouses:a) wet storage of aluminumsulfate, lime, soda

5 Based oncomputationsallowing for

moisture evolution

II-d 0.2 50

b) liquid chlorine See note3

6 6+6emer-gency

II-d 0.2 50

c) liquid chlorine, unheatedstorehouses

- - 6+6emer-gency

II-d 0.2 50

d) ammonia Notheated

- 6 II-d 0.2 50

e) activated charcoal,phosphates, sulfonated coal,polyacrylamide, liquid glass,fluorine-containing reagents

5 3 3 II-c 0.2 50

f) sulfuric acid 5 6 6 II-d 0.2 50g) iron chloride 5 6 6 II-d 0.2 50Notes: 1. When production rooms are constantly manned by service personnel, the air temperature in them mustbe not less than 16°C.

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Facilities and Rooms AirTemper-ature forHeatingSystems,

°C

Air ExchangeFrequency, hr

ProductionProcess

SanitationCharacter-

istics Group

StandardizedCoefficient of

NaturalIllumination

(KYeO) WithSide Lighting

Illumina-ion WithArtificialLighting ,

Lx

Intake Exhaust2. The air temperature in rooms with large areas of exposed water should be prescribed not less than 2°C abovethe temperature of the water surface.3. Heating is not foreseen as a rule in liquid chlorine storehouses. When process equipment associated withchlorine management is installed in a storeroom dispensing chlorine in addition to liquid chlorine containers,heating must be provided in order to maintain a design air temperature of 5°C.4. The standardized coefficient of natural illumination is given for USSR light climate zone III. The values of thecoefficients for other zones and computation of illumination for buildings and rooms not addressed in Table 44should be adopted in accordance with SNiP 23.05.95.

14.38. The air of constantly operating ventilation systems must be vented from a chlorine meteringroom through a stack rising 2 m above the roof ridge of the tallest building within a radius of 15 m, whilethe air of constantly operating and emergency ventilation systems in a chlorine dispensing storehouse mustbe vented through a stack rising 15 m above ground level. Scrubbing of the vented air must be foreseenwhen necessary.

14.39. A room used to prepare iron chloride solution must be designed with local air evacuationfrom the chamber in which iron chloride is flushed out of its containers, in addition to general ventilation bydilution.

14.40. Besides general ventilation by dilution, local evacuation of air from the fume cabinet usedfor opening sodium fluoride barrels must be foreseen. The air flow rate through fume cabinet access portsmust be not less than 0.5 m/sec.

15. SUPPLEMENTARY REQUIREMENTS ON WATER SUPPLY SYSTEMS IN SPECIALNATURAL AND CLIMATIC CONDITIONS

SEISMIC REGIONS

General Instructions

15.1. The requirements of this subsection must be fulfilled when planning water supply systems inregions with a seismicity of 7, 8, and 9 points.

15.2. In regions with a seismicity of 8 and 9 points, not less than two water supply sources must beforeseen when planning category I water supply systems and, as a rule, category II systems; use of onesurface source with water intakes installed in two sections to preclude the possibility of simultaneousinterruption of water delivery shall be permitted.

Use of one water supply source shall be allowed for category III water supply systems and, whenso justified, for category II systems, as well as for water supply systems of all categories in regions with 7-point seismicity.

In regions with a seismicity of 7, 8, and 9 points in which underground water from fractured andkarst rock is used as a water supply source, a second source—surface or underground water from sandyand gravelly deposits—should be prescribed for water supply systems of all categories.

15.3. In water supply systems using one water supply source (including a surface source wherewater is taken in in one section) in regions with a seismicity of 8 and 9 points, provisions must be made fora volume of water reserved for fire suppression in containers that is twice the quantity determined

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according to Paragraph 9.4, and for an emergency volume of water able to support production needs on anemergency schedule and domestic and drinking water needs at 70% of the rated consumption rate for notless than 8 hours in regions with a seismicity of 8 points and not less than 12 hours in regions with aseismicity of 9 points.

15.4. The theoretical number of simultaneous fires in regions with 9-point seismicity must beadopted as one more than indicated in items 2.12, 2.22, and 2.23 (with the exception of population centers,enterprises, and detached buildings when the rate of consumption of water for outdoor fire suppression isnot more than 15 L/sec).

15.5. To increase the operating reliability of water supply systems, provisions must be made for:dispersing pressure reservoirs; replacing water towers by pressure reservoirs; installing, with the approvalof agencies of the sanitary-epidemiological service, links between domestic and drinking, industrial, and firesuppression water pipelines; and passing untreated decontaminated water into the domestic and drinkingwater pipeline network.

15.6. Pumping stations supplying water for fire suppression and household and drinking watermust not be grouped with production buildings and facilities.

When pumping stations are grouped with water supply buildings and facilities, measures must beforeseen to preclude the possibility of flooding of the machine rooms and of rooms containing electricaldevices if impoundment facilities lose their water tightness.

15.7. Buried pumping stations must be located a distance of not more than 10 m (insidemeasurement) from reservoirs and pipelines.

15.8. Impoundment facilities at water treatment plants must be divided into separate blocks, thenumber of which must be not less than two.

15.9. Bypass lines delivering water to the network in avoidance of facilities must be foreseen atwater treatment plants. The bypass line must be laid a distance of not less than 5 m (inside measurement)from other facilities and utilities. In this case a most rudimentary installation for chlorination of drinkingwater delivered to the network must be foreseen.

15.10. The quantity of reservoirs intended for the same purpose within one installation must be notless than two, in which case each reservoir must be independently connected with supply and dischargepiping, without installing a common switching chamber.

15.11. Rigid fixation of pipes in walls and building foundations shall not be allowed. Thedimensions of openings to admit pipes must provide a gap of not less than 10 cm along the perimeter;where subsidence tends to occur, the gap must be not less than 20 cm in height; the gap must be filled withdense elastic material.

Passage of a pipe through a wall in the subsurface part of pumping stations and impoundmentfacilities must be designed such that mutual seismic effects of walls and pipelines would be precluded.Glands should be used for this purpose as a rule.

15.12. Flexible connections permitting angular and longitudinal movement of pipe ends must bebuilt into the inlets and outlets of pipelines passing through buildings or structures, in places wherepipelines connect to pumps and to water intake holes, at places where water tower risers connect tohorizontal pipelines, and in places of abrupt change in profile or direction of a pipeline route.

Water Conduits and Networks

15.13. All of the kinds of pipe indicated in Paragraph 8.21 ensuring reliable operation whenexposed to seismic loads may be used when planning water conduits and networks in seismic regions. Inthis case the depth to which pipes are buried must be prescribed in accordance with Section 8.

15.14. The pipe strength class must be selected with regard for the main and special loadcombinations associated with seismic effects.

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Flexible butt joints must be used in order to make seams expandable.15.15. The quantity of water conduit strings must be not less than two as a rule. The number of

links between them must be enough to compensate for the damage created by two accidents occurring alongthe conduits, in which case the total delivery of domestic and drinking water may be allowed to decrease bynot more than 30 percent of the design flow rate, while delivery for industrial needs must satisfy theemergency schedule.

Water conduits may be laid as a single string in category III water supply systems, and in categoryII systems when justified, in which case the volume of the containers should be the larger of the valuesdetermined in accordance with Paragraph 9.6 or Paragraph 15.3.

Water pipeline networks must be planned as ring networks.

Structural Members

15.16. Structures of buildings and facilities should be planned in accordance with requirements ofSNiP II-7-81 and this Section.

The design seismicity of buildings and facilities of water supply systems must be adopted inaccordance with Table 45.

Table 45Essentiality Class of Buildings

and Facilities per Table 41Design Seismicity of Buildings and Facilities at a

Construction Seismicity of, Points

7 8 9I-II 7 8 9

III Without regard forseismic effects

7 7

Note: Buildings and facilities are designed for loads corresponding to the design seismicity. Theseloads are multiplied by a factor of 1.2 for buildings and facilities that must continue to function duringrecovery operations after an earthquake, and 1.5 for water intake facilities fed by surface water.

15.17. Impoundment facilities and the underground parts of buildings must be designed for themost dangerous possible combinations of seismic effects caused by the weight of structural members, theweight of the liquid filling the container, and the soil, including embankments. The magnitude of seismiceffects caused by the weight of liquid and soil must be determined in accordance with Section 5 of SNiP II-7-81.

Note: When designing water towers, the requirements of this Paragraph shall apply only to the design ofthe tank structure.

15.18. Seismic effects on impoundment facilities and underground parts of buildings caused by theweight of the structural members and by loads on them shall be determined in the same way as forbuildings. In this case the values of the products of the coefficients in formulas (1) and (2) of SNiP II-7-81may be taken from Table 46.Table 46

Location of Buildingsand Facilities in

Relation to Ground

Products of Coefficients βι, ηik

Depending on Soil Category perTable 1, SNiP II-7-81

Value of Products of CoefficientsK1, K2, K [subscript illegible]

Depending on Essentiality Classof Buildings and Facilities Per

Table 41I II III I II III

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Location of Buildingsand Facilities in

Relation to Ground

Products of Coefficients βι, ηik

Depending on Soil Category perTable 1, SNiP II-7-81

Value of Products of CoefficientsK1, K2, K [subscript illegible]

Depending on Essentiality Classof Buildings and Facilities Per

Table 41Surface 3 2.7 2 0.3 0.25 0.2

Underground 2 1.8 1.5 0.25 0.2 0.15Note: Partly underground facilities are treated as underground facilities if their underground partexceeds half of their height, and as surface facilities if less.

Old data informationUNDERWORKED LAND

General Instructions

15.19. When planning buildings, facilities, water conduits, and water networks, they must beafforded protection from the effects of underground mining activity in accordance with SNiP II-8-78 andthis Section.

15.20. Covered reservoirs may be planned on group I-IV underworked land up to a volume of notmore than 6,000 m3, while on Ik-IVk underworked land, larger volumes of water must be accommodated byseveral reservoirs.

The volume of open impoundments is not standardized.15.21. Water switching chambers must be separated from reservoirs by functional joints.15.22. When planning impoundment facilities, free access must be foreseen to their main

components and units in order to permit inspection of the facility's work and to make repairs afterdeformations occur.

15.23. The possibility of leveling the outflows of water channels and troughs after deformationsoccur in foundations of facilities used for water treatment (clarifiers, settlers, filters, etc.) must be providedfor.

Leveling of the outflows of channels and troughs draining beneath the water surface need not beforeseen.

15.24. When planning water treatment plants, the main facilities must be laid out separately. Theymay be grouped in the case of plants with a productivity of up to 30,000 m3/day, and when constructionoccurs on group IV underworked land.

15.25. In order to increase the reliability of the work of water treatment plants, the individualfacilities should be divided into blocks and sections.

15.26. The elevations of the floor elevations and water levels in impoundment facilities must beprescribed such that gravity flow of water would continue after deformations occur in the foundation.

15.27. Pipelines and valves in water pipeline buildings and facilities must be made from steel.Fasteners used to attach pipelines and fittings to structural members must be planned with regard

for their possible mutual movement and for forces transmitted to them by the pipelines.Note: Use of cast-iron fittings is permitted only in facilities falling in water availability categories II and

III per Paragraph 4.4.15.28. To reduce forces in pipelines caused by movements of structural members and soil

deformation owing to underworking, the pliancy of pipelines should be raised by using compensatorydevices and by sensibly locating and selecting the types of fasteners and the design of pipe passagesthrough the walls of facilities.

Water Conduits and Networks

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15.29. When planning pipelines on underworked land, all kinds of piping should be used, withregard for the purpose of the pipelines, the required strength of the pipes, and the expandability of joints.

15.30. Butt joints of flared and sleeve pipes must be made pliant with the use of flexible gasketrings or mastic.

The strength of the welded joints of steel and plastic pipes must be not less than the strength of thepipe.

15.31. The locations of air holes and discharges on water conduits must be designated with regardfor anticipated deformations of their foundations.

15.32. When water conduits are planned as two or more strings, they should be laid on sitessubjected to different times of underground mining activity.

15.33. Pipelines may be laid together in tunnels or channels, with regard for the effects ofdeformations of the ground surface.

15.34. Design provisions to protect pipelines should be prescribed on the basis of computations ofdeformations of the ground surface resulting from mineral development over a 20-year period of pipelineoperation.

Design provisions pertaining to pipelines in category II and III water supply systems may beprescribed on the basis of deformations of the ground surface resulting from mineral development over aperiod of less than 20 years. In this case the plan must provide for a possibility to implementsupplementary protective measures in the course of operation.

15.35. The volume of design provisions to protect underground pipelines must be justified bycomputation, with consideration being given to:

using insulation reducing the effects of forces applied by deforming soil to the pipeline;using low-restraint materials to cushion the pipes;increasing the thickness of pipe walls;using pipes made from stronger materials;installing expansion joints.15.36. The strength of underground pipelines must be verified with regard for the joint action of

hoop and longitudinal stresses. Hoop stresses should be accounted for from the effects of interior pressureor vacuum, external loads created by fill and by transportation resources, and cross-sectional deformationsin the shoulder area.

Longitudinal stresses should be accounted for from the effects of inside pressure, temperaturechanges, and soil deformations.

15.37. Maximum expansion of joints at which tightness is still maintained shall be the limitingstate for pipelines made from asbestos-cement, cast iron, and reinforced concrete pressure pipes connectedtogether by bell-and-spigot and sleeve joints.

Maximum expansion of a butt joint in a pressure pipeline should be prescribed as, cm:0.2—for cast iron pipes;0.3—for reinforced concrete bell-mouthed pipes;1.5—for asbestos-cement pipes.

Structural Members

15.38. Impoundment facilities should be planned with a rigid, pliant, or combined design dependingon the facility's reactions to the effects of deformations of the foundation, with consideration being given to:

in the case of a rigid design—precluding the possibility of mutual shifting of components of thefloor, walls, roof, and partitions in response to all kinds of nonuniform deformations;

in the case of a pliant design—the possibility for adapting components to all kinds of nonuniformdeformations;

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in the case of a combined design—pliancy for some components and rigidity for others.15.39. Pliancy of components of impoundment facilities must be attained by installing deformable

watertight seams, predominantly at the butt joints of prefabricated structures, at places where walls connectwith the floor, roof, and partitions, and when necessary, in the floor.

15.40. When planning impoundment facilities with a pliant and a combined design on sites with ahigh water table, the structure of pliant seams must permit absorption of two-way hydrostatic pressure.

15.41. Installation of a drain system must be provided for in the case of impoundment facilitiesplanned with a pliant and with a combined design located in poorly-filtering clayey soil.

15.42. Reservoirs must be planned:with a rigid design—for volumes of 50 and 100 m3 on group I-IV underworked land, and volumes

of 250 and 500 m3 on group III-IV underworked land;with a pliant design—for a volume of 1,000 m3 on group I, a volume of 2,000 and 3,000 m3 on

group I-II, and a volume of 6,000 m3 on group I-III underworked land;with a combined design—for a volume of 250 and 500 m3 on group I-II, a volume of 1,000 m3 on

group II-IV, a volume of 2,000 and 3,000 m3 on group III-IV, and a volume of 6,000 m3 on group IVunderworked land.

Reservoirs on group Ik-IVk underworked land should be planned with a rigid design.15.43. Impoundment facilities at water treatment plants should be planned:in the case of clarifiers, vertical settlers, mixers, reaction chambers, and filters—with a rigid

design;in the case of horizontal settlers—with a pliant or a combined design;in the case of radial settlers—with a rigid or a combined design ensuring a constant gap between

the floor and the sludge-removing mechanism.15.44. Open impoundment facilities should be planned with a pliant design as impoundments in the

soil with lined sloping sides and floor. The contour interval of the sides must be adopted at a ratio equal to1:3.

15.45. When planning open impoundment facilities on sites underlain by cohesive soil free of water

encroachment and possessing an undisturbed structure with CH≥0.25 kgf/cm2 and ϕH≥23°, the foundationsof impoundments may be lined directly with polymer sheeting. In other cases the lining should consist ofreinforced concrete slabs with functional joints.

15.46. The floors of reinforced concrete impoundment facilities should be planned monolithic,consisting of a single layer on group Ik-IVk land, and two layers on group I-IV land.

A one-layer floor consisting of reinforced concrete slabs must be designed to absorb the basic andspecial combinations of loads.

A two-layer floor must include a reinforced concrete slab designed for the basic combination ofloads and for buckling, and reinforcement designed to withstand horizontal tensile deformation, with regardfor nonlinear strain of the foundation and cracking of reinforced concrete. In this case the maximumpermissible width of cracks opening in reinforcing material must be adopted at acr.sh.-t.=0.3 mm andacr.lng.-t.=0.2 mm.

A layer of waterproofing mastic must be foreseen between the slab and the reinforcement metalassembly.

15.47. If frontal pressure on the walls of a covered impoundment facility arising in response tohorizontal compression stresses of the ground surface has to be reduced, banking up the facility with sandysoil must be foreseen.

15.48. When horizontal loads on the foundation of an impoundment facility arising in response tohorizontal tensile strain have to be reduced, and in order to decrease the effects of vertical deformations ofa bedrock foundation arising at benches and places of buckling of the ground surface, a sand or dirtcushion should be foreseen beneath the floor.

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The thickness of the cushion must be prescribed on the basis of computations, with regard for themagnitude of nonuniform deformations, the design of the facility, and its plan dimensions.

PERMAFROST

General Instructions

15.49. When planning water supply networks and structures, principle I or II of using permafrostas a foundation should be adopted in accordance with SNiP 2.02.04-88.

15.50. The theoretical water flow rates may be increased to allow for discharge of water to keepnetworks and water pipelines from freezing. The suitability of discharging water and the flow rate of thedischarged water must be justified.

15.51. When underground water (supra-, inter-, or subpermafrost water) is used as a water supplysource, sources with the highest water temperature should be employed.

15.52. When determining the diameter of water intake holes, the dimensions of their heatingdevices must be accounted for (when necessary).

15.53. Artificial regulation and replenishment of underground water reserves should be employed:for intra-annual redistribution of suprapermafrost water, and to increase its reserves;to create reserves of weakly mineralized water by displacing salinized interpermafrost and

subpermafrost water with fresh water;to obtain water of the required temperature.15.54. Infiltration facilities, of the closed type as a rule, should be foreseen within the composition

of systems for artificial replenishment of underground water. Use of open-type facilities shall be allowed inthe presence of the appropriate justifications.

15.55. The type of water intake facilities in permafrost on watercourses having a constant surfaceflow and a stable channel must be adopted with regard for:

the extent to which the watercourses freeze;formation of melting zones and associated change in water quality;measures to preclude freezing of water in water intake and water diverting components of a water

intake.15.56. A water intake must be designed:with a shore or submerged water intake having a highly developed front, at the location of which

the channel should be regulated by a system of low retaining dams situated on the opposite bank;with a filtering water intake, the inlet of which is level with the channel of the watercourse;as a combined design adapted for intake of surface and substream water.Note: When thawed permeable rock with good filtering properties is present beneath the channel,

installation of a water intake for surface water in place of a water intake for substream water must be justified.15.57. Water intake facilities tapping surface sources must be located on naturally thawed ground

or on permafrost which will not cause deformation of foundation soil beyond permissible limits when itthaws.

15.58. Water intakes tapping substream water should be prescribed on watercourses that freeze tothe bottom.

15.59. The water supply design must allow constant movement of water through all sections of thewater pipelines and networks.

15.60. Pumping stations must foresee a possibility for delivering water in the reverse direction—into suction pipelines, with the number of suction lines being not less than two.

15.61. Not less than three pumping units must be installed at pumping stations regardless of theircategory.

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15.62. Constant water movement must be provided for in the reservoirs of inlet and outletpipelines.

Reservoirs with a capacity of up to 100 m3 may be located in heated rooms with a ventilatedbasement.

Water Conduits and Networks

15.63. The following must be foreseen when planning water pipelines and networks:protecting transported water from freezing;ensuring stability of pipelines on permafrost with regard for mechanical effects of thawing and

freezing ground on pipelines and facilities along them;protecting permafrost foundations from the effects of water on them in the event of water pipeline

accidents;organizing the monitoring of the thermal conditions of water conduits and networks and their

thermal effects on the foundations of pipelines and nearby buildings and facilities.15.64. The following must be foreseen when locating water pipeline networks on the master plan:maximum consolidation with heat supply networks;minimum length of networks;grouping of buildings such that networks could be installed suspended from the ceilings of

ventilated basements;reducing the number of connections to a water pipeline network by connecting several buildings to

a single pipeline inlet.15.65. To preclude thermal effects of above-ground pipelines on supporting ground, provisions

must be made for their installation on sleepers, on wooden frameworks [gorodkovyye supports], on pendantand pile supports, on masts and trestles, and on structural members of buildings and facilities in ventilatedbuilding basements.

In complex soil conditions and in the presence of seismic activity outside of population centers,pipelines should be installed on pendant supports in a zig-zag pattern.

15.66. When pipelines are laid above ground, cylindrical thermal insulation made from awaterproof non-aging heat-insulating material offering protection against mechanical damage must beemployed. Above-ground water conduits and networks must be laid closer to the ground surface, withinsnow cover, regardless of the means for compensating for temperature-related pipeline deformations.

The snow's thermal resistance should not be allowed for when computing the thermal losses ofpipelines.

15.67. When pipelines are laid underground without protective conduits, heat-engineeringcomputations must be carried out, and in summer, the dirt that surrounds the pipe must not affect thestability of the foundations of pipelines and nearby buildings and facilities when it thaws, and in winter, thedirt must protect the transported liquid from freezing.

Water pipelines may be laid in dirt subject to seasonal freezing if the pipes are protected fromfreezing by automatic water releases or an electric warming cable.

15.68. The distances from underground pipelines to foundations and facilities should be prescribedon the basis of heat-engineering computations, but no less than 6 m when pipelines are laid without aprotective conduit.

15.69. Conduits may be foreseen for short sections of the network.15.70. Tunnels must be prescribed when a water pipeline is laid together with other utilities.15.71. Pipeline inlets into buildings erected in such a way as to preserve permafrost beneath the

foundations must be installed above-ground, in ventilated conduits or suspended from the ceilings ofbuilding basements.

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Conduits and the pipes they contain must slope downward from buildings.15.72. Pipeline crossings of streets or roads in conduits or steel jackets must be bounded by

manholes containing air shafts and water collecting drains, and they should be laid only through a soilfoundation not prone to settling (within the theoretical thawing depth).

15.73. Pipelines must be planned with the following to prevent freezing of transported water:thermal insulation of pipelines;heating of water;heating of pipelines;constant movement of water in pipelines;higher hydrodynamic friction in pipelines;use of freezing-resistant steel valves;automatic water releases.15.74. The minimum water temperature in water conduits and networks must be determined by

heat-engineering computations, in which case temperatures may fluctuate within an interval from severalfractions of a degree to several degrees (3-5°C).

In the absence of heat-engineering computations, the water temperature in the terminal sections ofnetworks and water conduits may be prescribed as shown below for pipes of the indicated diameters:

up to 300 mm—not less than 5°C;over 300 mm—not less than 3°C.15.75. To reduce outlays on water heating, use should be made of:by-product heat from thermal power resources;the heat of hydrodynamic friction, created by increasing the rate of movement of water in pipelines,

the optimum value of which must be determined by computation.15.76. Heating of pipelines must be accomplished by installing them together with thermal

networks or by attaching an electric warming cable. The warming cable should be positioned above thepipeline when the latter is laid underground without a conduit.

15.77. Constant movement of water in pipelines must be accomplished by:connecting large water consumers to terminal sections of a dead-end network;designing a network with a minimum number of rings, which should be elongated in the direction

of the main flow of water toward a major consumer;adopting a design of water pipeline ring networks closing on circulating pumping stations paired

when necessary with water heating stations;bleeding water from the terminal section of a dead-end network;providing a fail-safe supply of electric power to pumping stations from two independent sources,

installing a liquid fuel-burning backup power station on the site of a pumping station, or installing anadditional unit powered by an internal combustion engine (when only one electric power supply source ispresent);

organizing continuous monitoring of the water flow rate in water conduits and networks.15.78. Automatic monitoring of water temperature at the start and end of a water conduit, at

intermediate water heating stations, in reservoirs and other facilities, and in sections of the network mostprone to freezing must be foreseen, with the readings being transmitted to a control station.

15.79. Steel and plastic pipe must be used for water conduits and networks; cast iron pipes may beused when laid in tunnels.

15.80. In places where pipelines intersect with structural members, elastic packing allowingmovement of pipes should be foreseen.

15.81. Water conduits and water pipeline networks must be laid with a slope of not less than 0.002in the direction of the outlet.

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The length of repair sections and the diameter of outlets should be prescribed with regard foremptying of the sections for a period of time determined by heat-engineering computations.

15.82. Fire hydrants specially designed for permafrost regions must be located in the main sectionsof the network.

15.83. The diameter of pipes at building inlets must be not less than 50 mm.15.84. Bent and self-sealing expansion joints must be used in order to accommodate temperature-

caused elongation of steel pipelines laid above ground.15.85. Installation of stop and control valves, gland-type expansion joints, bleeders, and air cocks

shall not be allowed on pipelines laid in ventilated building basements.

Structural Members

15.86. Installing impoundment facilities and the heated parts of buildings and utility lines betweenthem below the graded surface elevation without justification shall be prohibited.

15.87. When planning impoundment facilities on foundations devoid of bedrock, provisions mustbe made to keep the foundation soil in permafrost state. Impoundment facilities must be located on fillconsisting of non-heaving earth (coarse-grained sand, gravelly earth, etc.); in cases when it is impossible orunsuitable to lay fill, they should be installed on pile foundations.

15.88. When planning impoundment facilities, tunnels, and channels, foundation soil that tendstoward subsidence when thawed may be replaced with nonsubsiding soil to the computed thawing depth,and compacted as necessary.

15.89. A base layer of sand up to 0.15 m thick and gravel-clay mix up to 0.2 m thick must beforeseen beneath the floor of channels and tunnels.

15.90. When planning impoundment facilities, measures must be foreseen to preclude freezing ofwater stored in them, and its freezing on structural members, by applying heat-insulating fill, by heating thewater, and by installing heating chambers with corridors along the perimeter.

15.91. In cases when foundation soil is used in thawed state, the design features of facilities mustensure dependable operation in the event of sagging of the foundation.

15.92. To reduce thermal effects of tunnels and channels on foundation soil, they should beprovided with intake and exhaust ventilation shafts located in such a way as to preclude plugging of theshafts with snow; in addition, provisions must be made for temperature monitoring and for removal ofspilled water.

Natural ventilation of channels at building inlets should be separate from ventilation of tunnels andchannels accommodating water mains, in which case the air movement must be away from the building.

SUBSIDENCE-PRONE SOIL

General Instructions

15.93. Water supply buildings and facilities to be erected on subsidence-prone soil must be plannedwith regard for instructions of SNiP 2.02.01-83.

15.94. When developing the master plans, provisions must be made to preserve natural drainage ofrain and melt water.

Impoundment facilities must be located as a rule in areas of soil with good draining properties, andwhere subsidence-prone soil is of minimum thickness.

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Note: When the construction site is located on a slope, a ditch must be foreseen up-slope for diversion ofrain and thaw water.

15.95. The distance from impoundment facilities to buildings of various kinds must be prescribedas follows in the indicated soil conditions:

type I with respect to subsidence—not less than 1.5 times the thickness of the subsidence-prone soillayer;

type II with respect to subsidence—not less than 1.5 times the thickness of the subsidence-pronelayer when underlain by fast-draining soil, and not less than three times the thickness of the subsidence-prone layer when underlain by nondraining soil, but not more than 40 m.

Notes: 1. The thickness of the layer of subsidence-prone soil must be stated from the surface of thenatural topography, and after the site is graded, from the cut elevation.

2. The type of soil conditions with respect to subsidence and the amount of subsidence possible from thesoil's own weight should be prescribed with regard for possible cutting and filling during grading.

3. When soil subsidence is totally precluded within the bounds of the construction site, distances fromimpoundment facilities to buildings may be prescribed without regard for subsidence.

15.96. The distances from points of continual moisture release from water supply systems tobuildings and facilities under construction may be decreased by a factor of 1.5 compared to the distancesstated in Paragraph 15.95, on the condition that the subsidence properties of soil within the zone ofdeformation are completely or partially eliminated, or that subsidence-prone soil is cut by pile foundations,fortified soil columns, and so on.

15.97. When planning buildings, facilities, and pipelines to be erected on subsidence-prone soil,impoundment facilities and pipelines must be made watertight and measures must be foreseen to preventpenetration of water into the soil from pipelines and facilities, to monitor water leaks, to collect and divertwater from places of possible leaks, and to protect foundation pits and trenches from wetting by rain andmelt water.

15.98. Pipelines must be laid inside water supply buildings and facilities above the floor surface;pipes may be laid below the floor elevation in watertight conduits with outlets for accidental spills.

15.99. The enclosing structures of buildings must not abut on the walls of impoundment facilitieswhen subsidence-prone soil is present.

15.100. To allow monitoring of the condition and operation of water supply facilities, free accessto their main structural components and to units of process equipment must be made possible.

15.101. Building inlets and outlets must be specified in accordance with SNiP II-30-76.When a difference in settling rate of buildings or facilities and a pipeline inlet is able to cause

damage to pipes or enclosing structures, expansion joints accessible by manholes must be installed on thepipelines.

Pipes must not be fixed rigidly within the walls of impoundment facilities and the undergroundparts of buildings, and glands must be foreseen where pipes pass through walls.

15.102. Openings of larger size to admit pipes and channels must be prescribed in enclosingstructures on which no water tightness requirements are imposed. Gaps between the top and bottom of apipe or channel and the corresponding surface of the opening are recommended to be equal to one-third ofthe possible amount of soil subsidence at the foundation. The gaps must be filled with a dense elasticmaterial.

A possibility for adjusting the level of the outlets of water channels and troughs during operationmust be foreseen in this case.

15.103. The possibility of relative rotation and shifting of pipelines and channels extendingbetween separate facilities must be allowed for.

The packing of pipes and channels in walls must allow for their horizontal displacement inside andoutside a facility equal to one-fifth of the possible amount of soil subsidence in the foundation.

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15.104. Local clayey soil must be used as fill when grading the land and as backfill for foundationpits and trenches.

The degree of ground compaction must be prescribed depending on the possible loads oncompacted earth.

Backfilling must be done with earth of optimum moisture content in individual layers, eachcompacted to a dry-earth density of not less than 1.6 metric ton/m3. The thickness of the layers must beprescribed depending on the earth compacting machinery employed.

15.105. Waterproof aprons with a slope of 0.03 away from water pipeline facilities must beprovided for around such facilities. The width of the apron must be:

1.5 m—for impoundment facilities in type I soil conditions, and 2 m in type II conditions withrespect to subsidence;

5 m—for cooling towers and spray ponds;3 m—for water towers.Soil must be compacted beneath aprons.15.106. In places where columns pass through the water collecting ponds of cooling towers, a

design precluding possible penetration of water into the soil must be foreseen; in this case the load-bearingstructure must be allowed to yield freely.

Water Conduits and Networks

15.107. Requirements on foundations beneath pressure pipelines in type I and II soil conditionswith respect to subsidence are presented in Table 47.

15.108. Sumps (pallets) and the floors of conduits and tunnels must slope in the direction ofinspection holes.

15.109. Water conduits and water pipeline networks may be laid on or above the ground surfacewhen so justified.

15.110. The pipe material stated in Paragraph 8.21 should be used in all categories of water supplysystems in type I and II soil conditions for which subsidence of up to 20 cm is possible. Piping with bell-and-spigot and union joints should be secured with elastic materials.

Steel or plastic piping should be planned for water conduits and networks of category I and IIwater supply systems in type II soil conditions in which subsistence may be more than 20 cm; use of bell-mouthed pipes shall not be allowed;

plastic or reinforced concrete pressure pipes with joints filled with elastic material should be usedfor category III water supply systems; cast iron piping with rubber sealing rings may be used.

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Table 47Soil Type With

Respect to SubsidenceCategory by

Availability of WaterSupply Per Paragraph

4.4

Land Characteristics Requirements onFoundation Beneath

Pipeline

I I and II Built-upUndeveloped

Soil compactionSubsidence may bedisregarded

III Built-up

Undeveloped

Subsidence may bedisregardedAs above

II(subsidence up to20 cm)

I and II Built-up

Undeveloped

Soil compaction andinstallation of a sump(pallet)Soil compaction

III Built-upUndeveloped

As aboveSubsidence may bedisregarded

II(subsidence over 20 cm)

I and II Built-up

Undeveloped

Soil compaction, laying ofpipes in conduit or tunnelSoil compaction

III Built-up

Undeveloped

Soil compaction andinstallation of a sump(pallet)Soil compaction

Notes: 1. Undeveloped land—land on which construction of population centers and national economicfacilities is not foreseen for the next 15 years.2. Soil compaction—tamping of foundation soil for a depth of 0.3 m to a dry-earth density of not less than1.65 metric ton/m3 at the lower boundary of the compacted layer.3. Sump (pallet)—a watertight structure with sides 0.1-0.15 m high on which a drainage layer 0.1 m thickis laid.4. Requirements on pipeline foundations should be specified depending on the essentiality class ofbuildings and structures situated near the pipeline.5. Soil should be tamped to deepen trenches to accommodate butt joints on pipelines.6. Pipelines should be laid in conduits and tunnels in category I and II water supply systems on the landof population centers only if the inside distance between the exterior surface of the pipes and buildingfoundations is less than the length of conduits and water pipeline inlets into buildings as defined in SNiP2.04.01-85.

15.111. Inspection holes spaced depending on local conditions but not more than 200 m apart mustbe provided in order to permit observation of operating pipelines laid on sumps (pallets) or in conduits ortunnels. Water must be allowed to drain away from inspection holes on the network in this case.

15.112. When water pipeline networks are laid in trenches in type I soil conditions with respect tosubsidence, the horizontal (inside) distance from the networks to the foundations of buildings and facilitiesmust be not less than 5 m, while in type II soil conditions with respect to subsidence the distance must be inaccordance with Table 48.

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Table 48Thickness of Subsiding

Soil Layer, mMinimum Distances (Inside), m, From Networks to Foundations ofBuildings and Facilities in Type II Soil Conditions With Respect to

Subsidence, and With Pipe Diameters of, mmup to 100 over 100 and up to 300 over 300

Up to 5 Subsidence may be disregardedOver 5 and up to 12 5 7.5 10Over 12 7.5 10 15Notes: 1. Distances from networks to the foundations of buildings and facilities must be prescribedwithout regard for subsidence when buildings and facilities are erected in type II soil conditions wheresubsidence has been completely eliminated.2. These distances should be increased by 30 percent when water pipelines operating at a pressure above0.6 MPa (6 kgf/cm2) are laid.3. When it is impossible to observe the distances stated in Table 48, pipelines must be laid in watertightconduits or tunnels, or on sumps, with mandatory installation of outlets for spilled water in inspectionholes.

15.113. Installation of movable butt joints must be foreseen in manholes, conduits, and tunnelsbefore flanged valves on water conduits and water pipeline networks.

15.114. Manholes must be planned in water pipeline networks in type I soil conditions with respectto subsidence with foundation soil compacted to a depth of 0.3 m, in type II soil conditions with the soilcompacted to a depth of 1 m, in which case the floor and walls of the manholes must be watertight belowthe level of the pipeline.

The ground surface around the hatches of manholes must be graded with a 0.03 downward slopefrom the manhole for a distance of 0.3 m beyond the chamber.

15.115. Hydrants must be located at low points not less than 20 m from buildings and facilities.15.116. The lower part of inspection holes must be watertight.Water must be drained from inspection holes in accordance with Paragraph 8.15. If water cannot

be diverted away, the volume and the subsurface depth of the lower part of the hole must allow for itsemptying not more than once a day.

When necessary, inspection holes may be equipped with a water level measuring device or anautomatic water level signaling system transmitting signals to a control station.

Structural Members

15.117. The foundation beneath impoundment facilities in type I soil conditions with respect tosubsidence should prescribed as:

a) natural, if the total pressure exerted by the structure σzp and the weight of the soil itself (σzg) is

less than or equal to the initial subsidence pressure Psl—that is, σzp+σzg≤Psl, or the total yielding S andsubsidence Ssl of the building foundation is less than or equal to the maximum permissible value Smax.u for

the facility in question—that is, S+Ssl≤Smax.u;

b) compacted subsidence-prone soil when σzp+σzg≥Psl or S+Ssl≥Smax.u.15.118. Compaction of type I foundation soil with respect to subsidence should be accomplished

by heavy tamping to a depth of not less than 1.5 m within the bounds of a site exceeding the facilitydimensions by 2 m in each direction from the outside edges of foundations. The dry-dirt density at the lowerboundary of the compacted zone must be not less than 1.65 metric ton/m3.

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Note: When it is impossible to compact subsidence-prone soil by heavy tamping to the required density, adirt cushion 1.5 m thick consisting of local clayey soil compacted to a dry-dirt density of not less than1.65 metric ton/m3 must be foreseen.

15.119. Compaction of type I soil with respect to subsidence should be accomplished in severalphases (layers) beneath impoundment facilities with tapering floors.

In each phase, the soil layer must be compacted and then a pit must be dug into it to a depth equalto eight-tenths of the thickness of the compacted soil in the particular phase. In this case the boundary ofthe bottom of the pit in each phase must be 0.2 m greater than the outside dimensions of the tapered part ofthe facility in the particular cross section.

Compaction of the last layer must be accomplished by tapered compaction by a ramming method.15.120. Soil compaction must be foreseen beneath the foundations of the walls and columns of

buildings containing impoundment facilities, beneath the floors of pumping stations and rooms in which awet process goes on, and beneath impoundments, within an area exceeding the dimensions of the facilitiesby 2 m in each direction from the outer margins of the foundations, to a depth of 1.5 m for type I soilconditions with respect to subsidence and 2 m for type II soil conditions, to a dry-dirt density of not lessthan 1.7 metric ton/m3 at the lower boundary of the compacted zone.

15.121. Floors in rooms where water spills are possible must be watertight, and they must be builtwith skirting 0.1 m high on their perimeter of contact with walls, columns, and equipment foundations. Theslope of the floor should be prescribed at no less than 0.01 toward a watertight drain hole.

The lower part of enclosing structures of machine rooms situated beneath the ground surface mustbe watertight to a height of not less than 0.6 m.

15.122. The following should be foreseen beneath impoundment facilities in the presence of type IIsoil conditions with respect to subsidence:

partial elimination of the propensity of soil to subsidence;complete elimination of the propensity of soil to subsidence within the entire subsidence-prone

layer, or cutting of subsidence-prone soil.Note: Partial elimination of the propensity of soil to subsidence shall be allowed within the limits of the

deformable zone on the condition that the total amounts of yielding and subsidence do not exceed maximumpermissible values for the planned facilities.

15.123. Partial elimination of the propensity of type II soil to subsidence when the amount ofsubsidence is up to 20 cm must be accomplished by surface compaction of the soil by heavy tamping, or bylaying dirt cushions.

The thickness of the compacted layer must be prescribed equal to 2-5 m depending on the designfeatures of the facilities and the thickness of the subsidence-prone soil layer.

15.124. When subsidence properties are partially eliminated from type II soil, an antifiltering sumpwith a drainage layer and wall drains diverting water to an inspection hole must be foreseen beneath thefloor of an impoundment facility resting on compacted soil.

Impoundment facilities with tapered floors must be planned to stand on columns resting on areinforced concrete watertight slab, from which drainage of spilled water to an inspection hole must beforeseen.

15.125. Regardless of the type of soil conditions with respect to subsidence, soil compaction mustbe foreseen in accordance with Paragraph 15.117 beneath water towers.

In type II soil conditions the foundation of a water tower must be prescribed in the form of a solidreinforced concrete slab, and a means for draining spilled water from it to an inspection hole must beforeseen.

15.126. In type II soil conditions when the possible subsidence is more than 20 cm, completeelimination of subsidence properties of the entire subsidence-prone layer of foundation dirt or its cuttingmust be foreseen.

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15.127. Complete elimination of the subsidence properties of soil within the limits of the entiresubsidence-prone layer beneath impoundment facilities must be accomplished by compaction ofsubsidence-prone soil through preliminary wetting or wetting coupled with subsurface explosions, whichshould be combined with precompaction of the upper layer of subsidence-prone dirt by heavy tamping.

15.128. When it is impossible to employ preliminary wetting (because of the absence of water forwetting, proximity of existing buildings and structures, etc), complete elimination of subsidence propertiesof soil must be accomplished by deep reinforcement with compaction piles extending the entire depth of thesubsidence layer.

15.129. Cutting of subsidence-prone dirt must be accomplished by:installing pile foundations made from precast piles, cast-in-place piles, piers, and other types of

piles;using columns or bands made from dirt bonded together by chemical, thermal, or other means;laying foundations deeper.Cutting of subsidence-prone soil by pile foundations should be prescribed only in the absence of a

possibility for completely eliminating the subsidence properties of soil beneath impoundment facilities.15.130. In the case of impoundment facilities in type II soil conditions, observation of the yielding

of facilities, water leaks, and the level of ground water must be foreseen during the time of construction andoperation, until deformation is stabilized.

15.131. Recommended Appendix 14 shows the specific design of water supply system for Web-Siberian oil-and-gas plant.

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APPENDICES

Appendix 1. RECOMMENDED. Methods of Drilling Water Intake Wells

1. When planning groundwater intakes the well drilling method shall be selected depending on localhydrogeological conditions, the depth and diameter of the wells.

2. Well casing strings shall be made by the use of couplings or by electric welding.Nonmetallic pipe may be used in wells up to 250 m depth with free fitting of the casing string andobligatory cementation.

3. Casing strings in wells shall be nesting.The difference between the diameter of a previous and a subsequent casing string shall be no less than 50mm.

4. Under complex hydrogeological conditions additional casing strings shall be installed in wells tocover aquifers or rock with a tendency to collapse and absorb washing fluid which is not secured by a guidestring.

5. Casing strings for temporary (during drilling) support of well walls shall be removed. In casingstrings for continuous well operation, the free end of the pipe shall be extracted. The top edge of the casingstring remaining in the well shall be at least 3 m higher than the start of the previous string. The annulargap between the remaining portion of the string and the previous string shall be cemented or sealed byinstallation of a gland.

6. Wells shall be sealed to prevent the entry of surface pollutants and water from unused aquifers.7. The quality of the seal shall be checked by pumping out or pouring in water when drilling by the

impact method, and by injection of water under pressure when drilling by the rotary method, and also bygeophysical methods.

8. Cementation of water wells shall be performed using cement in accordance with GOST 25597-83.

9. When corrosive water is present in the aquifer used or other hydraulically connected aquifers,the casing string shall be treated to prevent corrosion or shall consist of pipe made of corrosion-resistantmaterials.

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Appendix 2. Recommended. Requirements for Water Well Filters

1. The types and designs of water well filters shall be as presented in Table 1.

Table 1Rock of aquifers Filter types and designs1. Rocky and semi-rocky unstable soil, rubbly andpebbly deposits with predominant particle size 20-100 mm (over 50% by mass)

Frame filters (without additional filtering surface),rod, tube with circular or slot perforations, stampedfrom 4 mm steel sheets with anti-corrosion coating,spiral-rod type

2. Gravel, gravelly sand with dominant particle size2-5 mm (over 50% by mass)

Rod and tube filters with water intake surface ofwound wire or stamped stainless steel sheet.Stamped 4 mm steel sheet filters with anti-corrosioncoating, spiral-rod

3. Coarse sand with predominant particle size 1-2mm (over 50% by mass)

Same

4. Medium-grain sand with predominant particlesize 0.25-0.5 mm (over 50% by mass)

Rod and tube filters with water intake surface ofwound wire, square-braided screen, stampedstainless steel sheet with sand-gravel fill, spiral-rod

5. Fine-grain sand with predominant particle size0.1-0.25 mm (over 50% by mass)

Rod and tube filters with water intake surface ofwound wire, galoon-braided screen, stampedstainless steel sheet with one- or two-layer sand-gravel fill, spiral-rod

2. Filters (modular type of porous concrete, gravel in cement binder) may be used to take smallamounts of water when creating a two-layer cover in a stratum.

3. Where the water is corrosive, filters shall be made of stainless steel, plastic or other corrosion-resistant materials having the necessary strength.

4. The dimensions of the apertures in filters used without gravel cover shall be taken from Table 2.Table 2

Filter type Filter aperture sizein homogeneous rock KH ≤≤≤≤ 2 in inhomogeneous rock KH ≥≥≥≥ 2

With circular perforations (2.5-3) d50 (3-4) d50

Screen (1.5-2) d50 (2-2.5) d50

With slit perforations (1.25-1) d50 (1.5-2) d50

Wire 1.25 d50 1.5 d50

Notes: 1. In Table 2 KH = d60/d10, where d10, d50, d60 are the dimensions of particles for which 10, 50 and 60% ofthe particles in the aquifer are smaller (determined by particle-size distribution graph).2. Lower values of the coefficients with d50 relate to fine-grained rock, greater values—to coarse-grained rock.

5. The dimensions of filter apertures when gravel covers are placed over the filters shall be equal tothe average diameter of the particles in the covering layer adjacent to the filter walls.

6. The porosity of tubular filters with circular or slit perforations shall be 20-25%, of wound wireor stamped steel sheet filters—not over 30-60%.

7. The cover layers on filters shall be of sand, gravel or sand-gravel mixtures.The mechanical composition of cover materials shall be selected so thatD50/d50 = 8-12,where D50 is a particle diameter such that the cover layer contains 50% smaller particles.

8. In multilayer gravel filters the thickness of each cover layer shall be as follows for filters:assembled on the surface, no less than 30 mm;

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created at the face of a well, no less than 50 mm.9. Selection of the mechanical composition of the material used to make two- and three-layer gravel

filter covers shall be based on the expressionD2/D1 = 4-6,where D1 and D2 are the mean diameters of the particles of the material of neighboring layers.

10. When selecting the gravel material for filters, the following expressions shall be used:for block filters of porous concrete or porous ceramic

Dav/d50 = 10-16;for glued filtersDav/d50 = 8-12,

where Dav is the average gravel particle diameter in the filter block.11. The material used for filters in wells shall be decontaminated.

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Appendix 3. Recommended. Testing and Mode Observations of Groundwater Intakes

1. Testing by pumping shall be used to establish the agreement of the actual flow through agroundwater intake with that specified in the plan.

2. Pumping shall be performed at two rates: with flow equal to the planned flow, and at 25-30%greater flow.

3. The total pumping time shall be 1-2 days for each rate after a constant dynamic level is reachedat the desired flow.If the operating mode is unstable, pumping shall be continued for a time sufficient to determine thecharacteristics of the reduction in flow at a constant level or the level at a constant flow.

4. Plans for groundwater intakes shall include a network of monitoring wells or water gaugingposts (where springs are capped) to observe the levels, flow, temperature and quality of the water.Operating wells and other water intake facilities and equipment shall be used according to the plan, with theconduct of a full set of mode observations.

5. The design of monitoring wells, their number and location shall be selected in accordance withthe hydrogeological conditions. Monitoring wells shall be equipped with a filter 89-110 mm in diameter.

6. The depth of monitoring wells shall be taken depending on their placement conditions:in an aquifer with a free surface with depth of operating wells up to 15 m—with the filter at the

same depth as in the operating wells;in an aquifer with a free surface with depth of operating wells over 15 m—with the top of the

operating portion of the filter 2-3 m below the lowest possible dynamic level in the aquifer;in an artesian aquifer with dynamic level above the roof of the aquifer—with the operating portion

of the filter in the upper third of the aquifer; with a portion of the aquifer dried out—with the top of thefilter 2-3 m below the dynamic level;

in aquifers, the operation of which is intended to utilize static reserves—with the top of theoperating portion of the filter 2-3 m below the position of the dynamic level at the end of the designoperating life of the aquifer.

7. The depth of monitoring wells in water intakes from mine shafts, radial and horizontal waterintakes shall be taken equal to the depth of the water intakes.

8. The vadose water and aquifers located higher than the operational aquifer shall be isolated inmonitoring wells.

9. When necessary, wells shall be drilled to monitor overlying nonoperational aquifers.10. To protect monitoring wells from choking, they shall be kept above the filter string or casing

string.11. In areas of infiltration water intake, monitoring wells shall also be placed between the water

intake and a surface stream or body of water, and when necessary on the opposite bank in the area affectedby the water intake. When there are foci of possible contamination of groundwater in the region of a waterintake (industrial wastewater discharge locations, bodies of water containing highly mineralized water,swampy peat bogs, etc.), additional monitoring wells shall be placed between them and the water intakes.

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Appendix 4. Recommended. Removal of Organic Matter, Tastes and Odors

1. In order to remove organic matter from water, reduce the intensity of taste and odor, chlorine,potassium permanganate, ozone or combinations of these substances shall be used as oxidizers. The formof oxidizer and its dose shall be established on the basis of process studies. Approximate doses of oxidizersmay be taken from Table 1.

Table 1Permanganate

oxidizability of water,mg O/L

Oxidizer dose, mg/L

chlorine potassium permanganate ozone8-10 4-8 2-4 1-3

10-15 8-12 4-6 3-515-25 12-14 6-10 5-8

2. The basic points of introduction of oxidizers and the order of use of reagents shall be taken fromTable 2.It is permitted to introduce partial doses of oxidizers upstream from various types of facilities.

3. When it is impossible to introduce reagents with the required time separation in pipes or themajor processing facilities, special contact chambers shall be set up.

4. The use of ozone and potassium permanganate in drinking water does not avoid the need forchlorination of the treated water for disinfection purposes.

5. Granulated active carbon shall be used as the charge in sorption filters located after clarificationfilters or other facilities which reduce the content of suspended matter in the water to 1.5 mg/L.

When justified, combined clarification-sorption filters may be used.

Table 2Point where oxidizer is added Sequence of addition of reagents to water1. Chlorine before sorption treatment Chlorination at least 2 min before filtration through

granulated active carbon or addition of powderedactive carbon

2. Ozone immediately before sorption treatment Ozonation with subsequent filtration throughgranulated active carbon or treatment withpowdered active carbon

3. Chlorine before coagulation Primary chlorination, then after 2-3 min—coagulation

4. Chlorine and potassium permanganate beforecoagulation

Primary chlorination, then after 10 min addition ofpotassium permanganate, then after 2-3 min—coagulation

5. Ozone before coagulation Ozonation, subsequent coagulation6. Chlorine and ozone before coagulation Primary chlorination with dose within limits of

chlorine absorptivity of water, after 0.5-1 hour—ozonation and subsequent coagulation

7. Ozone before clarifying filters or in treated waterNote: The possibility shall be provided of changing the point of addition of reagents as facilities are operated.

6. The height of the carbon charge Hc.c., m, shall be no less thanHc.c. = vd.f.τc /60,

where vd.f. is the design filtration speed, taken as 10-15 m/hr;

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τc is the time of passage of the water through the carbon layer, taken as 10-15 minutes depending on thesorption properties of the carbon, the concentration and type of pollutants in the water and other factors,and refined by process testing.

7. Sorption filters shall be charged with granulated active carbon of types AG-3, AG-M, etc.considering the requirements of Paragraph 1.3.The intensity of cleansing of the water by the filter sorptioncharge shall be determined depending on the required relative expansion of the active carbon from Table 3.

8. The distance from the surface of the filter charge to the edges of grooves shall be determined inaccordance with Paragraph 6.113 and Table 23.

9. Determination of the head loss in the active carbon sorption layer, design and construction of thedistributing system used to feed wash water, the grooves and other elements of sorption filters shall beperformed in accordance with Paragraphs 6.103-6.112.

Table 3Active carbon type Required relative

charge expansion, %Filter washing

intensity, L/(s⋅⋅⋅⋅m2)Filter washing time,

minAG-3 25 12-14 8-7

35 14-16 7-645 16-18 6-5

AG-M 30 8-9 12-1045 9-10 10-860 11-12 8-7

10. Powdered active carbon shall be introduced to the water prior to coagulation with a timeinterval of at least 10 min. The dose of carbon before filters shall be up to 5 mg/L.

11. Transportation of carbon powder from the reagent storage facility to the carbon slurrypreparation device may be by hydraulic or pneumatic methods. When the pneumatic method is used thecarbon powder transportation device shall be sealed and provided with fire suppression equipment and alocal explosion-prevention valve, and shall be grounded.

Dosing of the carbon slurry requires soaking of the carbon for 1 hour in tanks with hydraulic ormechanical agitation. The carbon slurry transfer pumps shall be resistant to the abrasive effect of thecarbon. The throughput of the circulating pumps shall be sufficient to provide 4-5 times exchanging of thesoaking reagent during the soaking time.

The concentration of the carbon slurry shall be up to 8%.12. Pipes to transfer the carbon slurry shall be designed for a slurry movement speed of at least 1.5

m/s; pipes shall be designed with inspection fittings for cleanout, with smooth bends and angles satisfyingParagraph 6.38.

13. The design of dosing equipment shall assure hydraulic mixing of the slurry and maintenance ofa constant level in the dosing device.

14. The capacity of tanks with agitators for preparation of potassium permanganate solution shallbe determined on the basis of a reagent solution concentration of 0.5-2% (of the commercial product), withtotal time of dissolution of the reagent taken as 4-6 hours at a water temperature of 20°C, 2-3 hours at awater temperature of 40°C.

15. The number of dissolving or dissolving-service tanks for potassium permanganate shall be noless than two (one reserve). The potassium permanganate solution shall be dosed using devices designed foroperation with clarified solutions.

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Appendix 5. Recommended. Stabilization Treatment of Water, Treatment With Inhibitors to PreventCorrosion of Steel and Cast Iron Pipe

1. When process analysis data are not available, the stability of water may be determined using thecalcium carbonate saturation index J:

J = pH0 – pHs, (1)where pH0 is the hydrogen ion index, measured with a pH meter;pHs is the hydrogen ion index with the water saturated with calcium carbonate, as determined from thenomogram of Figure 1, based on the calcium content CCa, total salt content P, alkalinity A and watertemperature t.Example. Given: CCa = 100 mg/L; A = 2 mg-eq/L; P = 3 g/L; t = 40°C.

Answer: pHs = 7.47.

Figure 1. Nomogram for determination of saturation pH of water by the use of calcium carbonate (pHs).KEY: At the top, left: CCa, mg/L; at the top, right: P, g/L; at the bottom: A, mg-eq/L

Example. Given: pH = 7; P = 1 g/L; A = 1 mg-eq/L; t = 80°C. Answer: (CO2)fr = 9.1 mg/L

Figure 2. Nomogram for determination of free carbon dioxide concentration in natural water (or pH).KEY: At the top, left: A, mg-eq/L; at the top, right: P, g/L; at the bottom: (CO2)fr, mg/L

2. To protect metal pipes from corrosion and the formation of lumpy corrosion deposits,stabilization treatment of water shall be performed if the saturation index is less than 0.3 more than threemonths of the year.

In determining the need for stabilization treatment of water, the change in water quality as a resultof planned treatment (coagulation, softening, aeration, etc.) shall be considered.

3. For water subject to treatment by mineral coagulants (aluminum sulfate, iron chloride, etc.),when computing the saturation index the pH and alkalinity of the water resulting from the addition of thecoagulant shall be considered.

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The alkalinity of water after coagulation Ac mg-eq/L, shall be determined by the equationAc = A0 – Dc/ec, (2)

where A0 is the alkalinity of the initial water (prior to coagulation), mg-eq/L;Dc is the coagulant dose as the anhydrous product, mg/L;ec is the equivalent mass of the anhydrous coagulant, mg/mg-eq, taken in accordance with Paragraph 6.19.

The quantity of free carbon dioxide in the water after coagulation (CO2)fr shall be determined usingthe nomogram of Figure 2 with known pH of the coagulated water, and if the pH is unknown, using theequation

(CO2)fr = (CO2)0 + 44 Dc/ec. (3)where (CO2)0 is the concentration of free carbon dioxide in the initial water prior to coagulation, mg/L.

With known value of (CO2)fr, the nomogram of Figure 2 is used to determine the pH of the waterafter treatment with the coagulant.

4. With a positive saturation index in order to prevent calcium carbonate deposits on pipes thewater shall be treated with acid (sulfuric or hydrochloric), sodium hexametaphosphate or tripolyphosphate.

The acid dose Dacid, mg/L (as the commercial product) shall be determined by the equationDacid = 100αacidAeacid/Cacid, (4)

where αacid is a coefficient taken from the nomogram of Figure 3;Aeacid is the alkalinity of the water prior to stabilization treatment, mg-eq/L;eacid is the equivalent mass of acid, mg/mg-eq (for sulfuric acid—49, for hydrochloric acid—36.5);Cacid is the content of the active part in the commercial acid, %.

Figure 3. Nomogram for determination of αacid whencalculating acid dose. KEY: Vertical axis:

Coefficient αacid

Figure 4. Nomogram for determination of βl incalculating alkali dose. KEY: Vertical axis:

Coefficient βl

The dose of sodium hexametaphosphate or tripolyphosphate (as P2O5) shall be taken as:for drinking water lines—not over 2.5 mg/L (3.5 mg/L as PO4);for process water lines—up to 4 mg/L.5. With a negative calcium carbonate saturation index, in order to obtain stable water it shall be

treated with alkaline reagents (lime, soda or a combination thereof), sodium hexametaphosphate ortripolyphosphate.

The lime dose shall be determined by the equationDl = 28βlKtA, (5)

where Dl is the dose of lime, mg/L, as CaO;βl is a coefficient determined from the nomogram of Figure 4 depending on the pH of the water (prior tostabilization) and the saturation index J;

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Kt is a coefficient depending on water temperature: at t = 20°C—Kt = 1, at t = 50°C—Kt = 1.3;A is the alkalinity of the water prior to stabilization treatment, mg-eq/L.

The dose of soda as Na2CO3, mg/L, shall be 3-3.5 times the dose of lime as CaO, mg/L.If according to equation (5) the lime dose Dl/28, mg-eq/L, is greater than the value of da, mg-eq/L,

determined by the equationda = 0.7[(CO2)/22 + A], (6)

then in addition to lime in the quantity da, mg-eq/L, soda shall also be added to the water, the dose of whichDs, mg/L, shall be determined by the equation

Ds = (Dl/28 – da)100. (7)The possibility shall be provided of dosing sodium hexametaphosphate or tripolyphosphate in a

dose of 0.5-1.5 mg/L (as P2O5) simultaneously with addition of the alkaline reagents in order to increase theuniformity of distribution of the protective carbonate film along the length of the pipes.

When designing systems to treat water with sodium hexametaphosphate or tripolyphosphate(without alkaline reagents) to control corrosion of steel and cast iron pipes on process water lines, the dosesof these reagents shall be 5-10 mg/L (as P2O5). For drinking water lines the dose of these reagents shall notexceed 2.5 mg/L as P2O5.

Where water is treated with sodium hexametaphosphate or tripolyphosphate without alkalinereagents as new pipeline sections are put on stream, to control corrosion they shall be filled for 2-3 dayswith a solution of sodium hexametaphosphate or tripolyphosphate with a concentration of 100 mg/L (asP2O5) with subsequent clearing of this solution and washing of the pipes with water containing thesereagents (as P2O5) at 5-10 mg/L for process water lines and 2.5 mg/L for drinking water lines.

6. Preparation of sodium hexametaphosphate and tripolyphosphate solutions for water treatmentshall be performed in dissolving and service tanks with anticorrosion protection. The concentration of thesolutions shall be from 0.5 to 3% as the commercial product, dissolution time with mechanical agitators orcompressed air—4 hours at a water temperature 20°C and 2 hours at a temperature of 50°C.

7. Stabilization processing of water shall provide the possibility of introducing alkaline reagentsinto the mixer, before filters and to the filtered water before secondary chlorination.

When the reagent is added before the filters or to the filtered water, a high degree of purification ofthe alkaline reagents and their solutions shall be achieved. Preparation of lime milk and soda solution andtheir dosing shall be performed in accordance with Paragraph 6.34-6.39.

The introduction of alkaline reagents before mixers and filters may be performed in those caseswhen this does not decrease the water purification effectiveness (in particular, the reduction of the colorindex).

8. In order to form a protective calcium carbonate film on the inner surfaces of a pipe during itsfirst period of use, the possibility shall be provided of increasing the dose of alkaline reagents above thatdetermined using equations (6) and (7) by a factor of two, and subsequently over the long term by 10-20%above the level determined by the same equations.

9. Refinement of the dose of alkaline reagents, as well as the length of the period of formation ofthe protective carbonate film, shall be performed in the process of operation of pipelines by the conduct ofprocess and chemical analyses of the water, as well as observation of corrosion indicators. Theseobservations also determine the expediency of maintaining a slight supersaturation of the water withcalcium carbonate after the initial period of formation of the protective carbonate film on the pipe walls.

10. As the protective carbonate film is formed on pipes in drinking water supply systems, the pH ofthe alkaline-reagent-treated water shall not exceed the values permitted by GOST 2874-82.

11. The design of stabilization treatment of low-mineral content water containing less than 20-30mg/L calcium and alkalinity 1-1.5 mg-eq/L shall be performed only on the basis of preliminary process

studies. When it is necessary to increase the concentration of calcium (Ca2+) and bicarbonates ( )HCO3−

in the water, joint processing of the water shall be performed using carbon dioxide (CO2) and lime.

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Appendix 6. Recommended. Fluorination of Water

1. Reagents to be used for fluorination of water shall be sodium fluosilicate, sodium fluoride,ammonium fluosilicate and fluosilicic acid.Note: With justification, by agreement with the Chief Sanitary-Epidemiological Directorate, USSRMinistry of Health, other fluorine-containing reagents may be used.

2. The dose of the reagents Df, g/m3, shall be determined by the equationDf = 104(mfaf – F)/KfCfg, (1)

where mf is a coefficient which depends on the point of introduction of the reagent to the water, taken whereit is introduced to treated water as 1, when it is introduced before the filters with two-stage treatment—as1.1;af is the necessary fluorine content in the treated water depending on the climate region of the populationcenter, established by agencies of the sanitary-epidemiological service, g/m3;F is the content of fluorine in the initial water, g/m3;Kf is the fluorine content in the pure reagent, %, taken for sodium fluosilicate as 61, for sodium fluoride—45, for ammonium fluosilicate—64, for fluosilicic acid—79;Cf is the content of the pure reagent in the commercial product, %.

3. Fluorine-containing reagents are usually added to the clear water before it is decontaminated.Fluorine-containing reagents may be added before the filters with two-stage water treatment.

4. When sodium fluosilicate is used, processing systems shall be employed involving preparation ofan unsaturated solution of the reagent in service tanks or a saturated solution of the reagent in individualsaturators.

When sodium fluoride, ammonium fluosilicate or fluosilicic acid is used, systems involvingpreparation of an unsaturated solution in service tanks shall be employed.

For powdered reagents, systems with dry dosing of the reagents may be employed.5. The throughput of a saturator qs, L/hr (as saturated reagent solution) shall be determined by the

equationqs = Dfq/nsPf, (2)

where qs is the flow rate of the treated water, m3/hr;ns is the number of saturators;pf is the solubility of sodium fluosilicate, g/L, which is at 0°C—4.3, 20°C—7.3, 40°C—10.3.

To determine the volume of saturators, the time spent in them by the solution shall be taken as noless than 5 hours, the speed of the ascending water flow in the saturator—not over 0.1 m/s.

6. The concentration of the reagent solution during preparation of unsaturated solutions indissolving tanks shall be taken as: for sodium fluosilicate—0.25% at solution temperature 0°C and up to0.5% at 25°C, for sodium fluoride—2.5% at 0°C; for ammonium fluosilicate—7% at 0°C; for fluosilicicacid—5% at 0°C.

Solutions shall be mixed with the aid of mechanical agitators or air.The air feed rate shall be 8-10 L/(s⋅m2).7. Solutions of fluorine-containing reagents shall be allowed to settle for 2 hours before use.8. When systems are employed using dry reagent dosing devices, a special chamber shall be

provided for mixing with water and dissolution of the measured reagent.Mixing of the solution in the chamber shall be assisted by hydraulic or mechanical devices. The

concentration of the solution in the chamber shall be taken up to 25% of the solubility of the reagent at thetemperature present, the minimum time spent by the solution in the chamber as 7 min.

9. When sodium fluosilicate, ammonium fluosilicate or fluosilicic acid is used as the reagent,measures shall be taken to prevent corrosion of tanks, pipes and the dosing equipment.

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10. Fluorine-containing reagents shall be stored in the factory packaging.Fluosilicic acid shall be stored in tanks with measures taken to prevent it from freezing.11. The fluorinator room and fluorine-containing reagent storage facility shall be isolated from

other production rooms.Places where dust may be released shall be equipped with local exhaust ventilation, and sodium

fluosilicate and sodium fluoride packages shall be opened in a fume hood.12. When fluorine-containing reagents are used, considering their toxicity, general and individual

protective measures shall be provided for servicing personnel.

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Appendix 7. Recommended. Softening of Water

1. The quantity of water to be softened qs, expressed as a percent of the total quantity of water,shall be determined by the equation

qs = 100(Ht.init – Ht.n)/(Ht.init – Hs), (1)where Ht.init is the total hardness of the initial water, mg-eq/L;Htn is the total hardness of the water fed into the network, mg-eq/L;Hs is the hardness of the softened water, mg-eq/L.Reagent Decarbonization and Lime-Soda Softening

2. Installations used for reagent decarbonization and lime-soda softening of water shall include: areagent section, mixers, clarifiers with suspended sediment, filters and devices for stabilization treatment ofthe water.

In individual cases (see Paragraph 8), eddy reactors may be used instead of clarifiers withsuspended sediment.

3. With decarbonization the residual hardness of the softened water may be 0.4-0.8 mg-eq/Lgreater than the noncarbonate hardness, with alkalinity 0.8-1.2 mg-eq/L; with lime-soda softening theresidual hardness shall be 0.5-1 mg-eq/L, alkalinity 0.8-1.2 mg-eq/L. The lower limits may be obtained byheating the water to 35-40°C.

4. With decarbonization and lime-soda softening of water, the lime shall be used as lime milk. Witha daily consumption of lime of less than 0.25 metric ton (as CaO), the lime may be added to the waterbeing softened as a saturated lime solution, produced in saturators.

5. The lime dose Dl, mg/L, for decarbonization of water, as CaO, shall be determined by thefollowing equations:

a) with a relationship between concentration of calcium and carbonate hardness (Ca2+)/20 > Hc

Dl = 28[(CO2)/22 + Hc + Dc/ec + 0.3)]; (2)b) with a relationship between calcium concentration in the water and carbonate hardness

(Ca2+)/20 < Hc

Dl = 28[(CO2)/22 + 2Hc – (Ca2+)/20 + Dc/ec + 0.5], (3)where (CO2) is the concentration of free carbon dioxide in the water, mg/L;(Ca2+) is the content of calcium in the water, mg/L;Dc is the dose of coagulant, FeCL3 or FeSO4 (as the anhydrous product), mg/L;ec is the equivalent mass of the active coagulant substance, mg/mg-eq (for FeCl3—54, for FeSO4—76).

6. The doses of lime and soda for lime-soda softening of water shall be determined by theequations:

lime dose Dl, mg/L, as CaODl = 28[(CO2)/22 + Hc + (Mg2+)/12 + Dc/ec + 0.5]; (4)soda dose Ds, mg/L, as Na2CO3

Ds = 53(Hn.c. + Dc/ec + 1), (5)where (Mg2+) is the magnesium content of the water, mg/L;Hn.c. is the noncarbonate hardness of the water, mg-eq/L.

7. With lime or lime plus soda softening of water, the coagulants used shall be iron chloride or ironsulfate.

The doses of coagulant as the anhydrous products FeCl3 or FeSO4 shall be taken as 25-35 mg/Lwith subsequent refinement in the process of operation of the water softening installation.

8. When justified, it is permissible to perform decarbonization or lime-soda softening of water ineddy reactors producing calcium carbonate particles which are roasted for use as the lime reagent.

Softening of water in eddy reactors shall be used where (Ca2+)/20 mg/L > Hc, the magnesiumcontent in the initial water is not over 15 mg/L and the permanganate oxidizability is not over 10 mg O/L.

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Final clarification of water after eddy reactors shall be performed on filters.9. Eddy reactors shall be designed using: speed at reactor input 0.8-1 m/s; conical angle 15-20°;

speed of ascending movement of water at water discharge level 4-6 mm/s. The contact mass used to chargeeddy reactors shall be milled lime, crushed calcium carbonate particles formed in eddy reactors or crushedmarble.

The grain size of the contact mass shall be 0.2-0.3 mm, its quantity—10 kg per m3 of eddy reactorvolume. The contact mass shall be recharged each time the particles are drained from the eddy reactor.

Lime shall be added to the lower portion of the reactor as a lime solution or milk. When water istreated in eddy reactors no coagulant shall be added.Note: Where (Ca2+)/20 < Hc decarbonization of water shall be performed in clarifiers with additionalclarification on filters.

10. To remove the suspended matter formed upon softening of water with lime, as well as the limeand soda, clarification shall be performed with suspended sediment (special design).

The speed of movement of water in the suspended sediment layer shall be taken as 1.3-1.6 mm/s,the water containing not over 15 mg/L suspended matter after clarification.

11. Filters for clarification of water which has passed through eddy reactors or clarifiers shall becharged with sand or crushed anthracite with particle size 0.5-1.25 mm and nonuniformity factor 2-2.2.The charge layer height is 0.8-1 m, filtration speed—up to 6 m/hr.

The use of two-layer filters is permissible.Filters shall be equipped with devices for top washing.

Sodium-Cationite Method of Water Softening12. The sodium-cationite method shall be used to soften groundwater and the water of surface

sources with turbidity not over 5-8 mg/L and color index not over 30°. Sodium-cationite treatment does notchange the alkalinity of the water.

13. With single-stage sodium cationization the total hardness of the water can be reduced to 0.05-0.1 g-eq/m3, with two-stage treatment—to 0.01 g-eq/m3.

14. The volume of cationite Wc, m3, in first-stage filters shall be determined by the equation

W q H n Erc s t.init opNa= 24 / , (6)

where qs is the flow rate of softened water, m3/hr;Ht.init is the total hardness of the initial water, g-eq/m3;

EopNa

is the operating exchange capacity of the cationite in sodium cationization, g-eq/m3;

nr is the number of regenerations of each filter per day, varying from one to three.

15. The operating exchange capacity of the cationite in sodium cationization EopNa

, g-eq/m3, shall be

determined by the equation

E E q HNaopNa

Na tot sp t.init= −α β 05. , (7)

where αNa is the effectiveness of regeneration of the sodium cationite, considering the incompleteness ofregeneration of the cationite as found in Table 1.βNa is a coefficient considering the decrease in exchange capacity of the cationite for Ca2+ and Mg2+ due topartial retention of Na+ cationites, taken from Table 2, where CNa is the sodium concentration in the initialwater, g-eq/m3 (CNa = (Na+)/23);Etot is the total exchange capacity of the cationite, g-eq/m3, taken from the manufacturing plant data. If suchdata are not available, the following figures can be used for calculation: for sulfocarbon with particle size0.5-1.1 mm—500 g-eq/m3; for KU-2 cationite with particle size 0.8-1.2 mm—1500-1700 g-eq/m3;qsp is the specific consumption of water for washing the cationite, m3 per m3 of cationite, taken forsulfocarbon, as 4, for KU-2—6.

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Table 1Specific consumption of common salt for cationiteregeneration, g per g-eq of operating exchange capacity

100 150 200 250 300

Effectiveness of cationite regeneration αNa 0.62 0.74 0.81 0.86 0.9Old data information

Table 2CNa/Ht.init 0.01 0.05 0.1 0.5 1 5 10ββββNa 0.93 0.88 0.83 0.7 0.65 0.54 0.5

Old data information16. The area of cationite filters in the first stage Fc, m2, shall be determined by the equationFc = Wc/Hc, (8)

where Hc is the height of the cationite layer in the filter, varying from 2 to 2.5 m (greater charge height usedwith hardness of water over 10 g-eq/m3);Wc is defined in equation (6).

The number of cationite filters in the first stage shall be: operating—no less than two, reserve—one.

17. The speed of filtration of the water through the cationite for pressure filters in the first stagewith normal operating mode shall not exceed, with total water hardness:

up to 5 g-eq/m3—25 m/hr;5-10 g-eq/m3—15 m/hr;10-15 g-eq/m3—10 m/hr.

Note: A brief increase in the filtration speed by 10 m/hr over the figures given above is permissible whenfilters are disconnected for regeneration or repair.

18. The head loss in pressure cationite filters shall be defined as the sum of the head losses in thefilter connections, the drains and the cationite. The head loss in a filter shall be taken from Table 3.

Table 3Layer height, m, of cationite with particle size

0.5-1.1 mm or 0.8-1.2 mmHead loss, m, in pressure cationite filter at filtration

speed, m/hr5 10 15 20 25

2 4 5 5.5 6 72.5 4.5 5.5 6 6.5 7.5

19. In open cationite filters the layer of water above the cationite shall be taken as 2.5-3 m and thefiltration speed not over 15 m/hr.

20. The water feed rate to loosen the cationite shall be taken as 4 L/(s⋅m2) with a cationite grainsize of 0.5-1.1 mm and 5 L/(s⋅m2) with a particle size of 0.8-1.2 mm. The loosening time shall be 20-30min. Water shall be fed in to loosen the cationite as provided in Paragraph 6.117.

21. Regeneration of cationite filter charges shall be performed using technical common salt. Theconsumption of common salt Ps, kg, per regeneration of a sodium-cationite first-stage filter shall bedetermined by the equation

P f H E as c c opNa

s= 1000, (9)

where fc is the area of one filter, m2;Hc is the height of the cationite layer in the filter, m, in accordance with Paragraph 16;

EopNa

is the operating exchange capacity of the cationite, g-eq/m3, taken from Paragraph 15;

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as is the specific salt consumption per g-eq of operating exchange capacity of the cationite, taken as 120-150 g/g-eq for first-stage filters in a two-stage system and 150-200 g/g-eq for a single-stage system.

The hardness of the softened water with various specific salt consumptions is shown in Figure 1.

Figure 1. Graph for determination of residual hardness of water softened by single-stage sodiumcationization.

KEY: Vertical axis: Filtrate hardness, g-eq/m3; horizontal axis: Specific salt consumption, g/g-eq, ofabsorbed cations Ca2+ and Mg2+; middle of figure: : Cation concentration in initial water20 g-eq/m3

The concentration of the regeneration solution for first-stage filters shall be taken as 5-8%.The speed of filtration of the regeneration solution through the cationite of first-stage filters shall

be taken as 3-4 m/hr; the speed of filtration of the initial water for washing of the cationite—6-8 m/hr, thespecific consumption of wash water—5-6 m3 per m3 of cationite.

22. Sodium-cationite second-stage filters shall be designed in accordance with Paragraphs 20, 21,using: cationite layer-height—1.5 m; filtration speed—not over 40 m/hr; specific salt consumption forcationite regeneration in second-stage filters 300-400 g per g-eq of retained hardness cations; concentrationof regeneration solution—8-12%.

The head loss in second-stage filter shall be taken as 13-15 m.Washing of the cationite in second-stage filters shall be performed using the first-stage filtrate.When designing second-stage filters, the total hardness of the incoming water shall be taken as 0.1

g-eq/m3, the operating cationite absorption capacity—250-300 g-eq/m3.23. When justified, counterflow or stepwise-counterflow sodium cationization may be used to

soften water with high mineral content.

Hydrogen-Sodium-Cationite Method of Softening Water

24. The hydrogen-sodium-cationite method shall be used to remove hardness cations (calcium andmagnesium) from water while simultaneously reducing the alkalinity of the water.

This method shall be used to treat groundwater and water from surface sources with turbidity notover 5-8 mg/L and color index not over 30°.

Softening of the water shall be performed using the following systems:parallel hydrogen-sodium cationization, allowing production of a filtrate with a total hardness of

0.1 g-eq/m3 with residual alkalinity 0.4 g-eq/m3; the total content of chlorides and sulfates in the initialwater shall be not over 4 g-eq/m3, of sodium not over 2 g-eq/m3;

sequential hydrogen-sodium cationization with “starvation” regeneration of the hydrogen-cationitefilters; the total hardness of the filtrate is 0.01 g-eq/m3, its alkalinity—0.7 g-eq/m3;

hydrogen-cationization with “starvation” regeneration and subsequent filtration through buffer self-regenerating cationite filters; the total hardness of the filtrate will be 0.7-1.5 g-eq/m3 above thenoncarbonate hardness of the initial water, the alkalinity of the filtrate—0.7-1.5 g-eq/m3. Cationite buffer

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filters need not be provided if it is not necessary to maintain the residual hardness, alkalinity and pH withinstrictly defined limits. The possibility shall be provided of regenerating buffer filters with a technicalcommon salt solution.

25. The relationships of the flow rates of water fed to hydrogen-cationite and sodium-cationitefilters for softening of water in parallel hydrogen-sodium cationization shall be defined by the equations

flow rate of water fed to hydrogen-cationite filters qtotH , m3/hr,

( ) ( )q q A A A As ntotH

tot= − +0 0 ; (10)

flow rate of water fed to sodium-cationite filters q totNa

, m3/hr,

q q qtotNa

tot totH= − , (11)

where qtot is the total throughput of the hydrogen-sodium-cationite installation, m3/hr;

q totH

and q totNa

are the total throughputs of the hydrogen-cationite and sodium-cationite filters, m3/hr;

A0 is the alkalinity of the initial water, g-eq/m3;As is the required alkalinity of the softened water, g-eq/m3;An is the total content of strong acid anions (sulfates, chlorides, nitrates, etc.) in the softened water, g-eq/m3.Notes: 1. Hydrogen-cationite filters may be used also as sodium-cationite filters, and therefore the possibilityshall be provided of regenerating two or three hydrogen-cationite filters with a technical common salt solution.2. Design of pipes and filters shall be performed for the most heavily loaded mode of the hydrogen-cationitefilters, the maximum alkalinity (A) of the water and the least content in it of strong acid anions (An); with themaximum load on the sodium-cationite filters, minimum alkalinity of water and maximum content of strong-acidanions.

26. The volume of cationite WH, m3, in the hydrogen-cationite filters shall be determined by theequation

( )W q H C n Etot rh totH

Na opH= +24 . (12)

The volume of cationite WNa, m3, in the sodium-cationite filter shall be determined by the equation

W q H n ENa totNa

r opNa= 24 0 , (13)

where Htot is the total hardness of the softened water, g-eq/m3;nr is the number of regenerations of each filter per day, taken in accordance with Paragraph 14;

EopH

is the operating exchange capacity of the hydrogen cationite, g-eq/m3;

EopNa

is the operating exchange capacity of the sodium cationite, g-eq/m3;

CNa is the concentration of sodium in the water, g-eq/m3, defined in accordance with Paragraph 15.

27. The operating exchange capacity EopH

, g-eq/m3, of the hydrogen cationite shall be determined by the

equation

E E q CopH

H tot sp c= −α 0 5. , (14)

where αH is the effectiveness of regeneration of the hydrogen cationite, taken from Table 4;Cc is the total content in the water of calcium, magnesium, sodium and potassium cationites, g-eq/m3;qsp is the specific flow rate of water for washing of the cationite after regeneration, taken as 4-5 m3 waterper m3 of cationite;Etot is the total exchange capacity of the cationite in a neutral medium as taken from the specifications, g-eq/m3.

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Table 4Specific consumption of sulfuric acid for regeneration ofcationite, g/g-eq, of operating exchange capacity

50 100 150 200

Effectiveness of hydrogen-cationite regeneration, αH 0.68 0.85 0.91 0.92

When certificate data are not available, Etot shall be defined in accordance with Paragraph 15.28. The area of hydrogen-cationite and sodium-cationite filters FH, m2, and FNa, m2, shall be

determined by the equationFH = WHHc; FNa = WNaHc, (15)

where Hc is the height of the cationite layer in the filter, m, taken in accordance with Paragraph 16.The head loss in hydrogen-cationite filters, the intensity of loosening and rate of filtration shall be

taken in accordance with Paragraphs 18-20.29. The number of operating hydrogen-cationite and sodium-cationite filters for operation around

the clock shall be no less than two.The number of reserve hydrogen-cationite filters shall be taken as: one—with up to six operating

filters, and two—with more than six operating filters. Reserve sodium-cationite filters are not required, butthe possibility shall be provided of using reserve hydrogen-cationite filters as sodium-cationite filters inaccordance with Paragraph 25.

30. Regeneration of hydrogen-cationite filters shall be performed using a 1-1.5% solution ofsulfuric acid. It is permitted to dilute sulfuric acid to this concentration with water immediately before thefilters in an ejector.

The flow rate of the sulfuric acid regeneration solution through the cationite layer shall be no lessthan 10 m/hr with subsequent washing of the cationite with unsoftened water, passed through the cationitelayer from the top down at a speed of 10 m/hr.

Washing shall be terminated when the filtrate acidity reaches the sum of the concentrations of thesulfates and chlorides in the water used for washing.

The first half of the volume of the wash water shall be sent for neutralization, to accumulators,etc., while the second half shall be sent to the cationite loosening water tanks.Note: It is permissible to use hydrochloric and nitric (for KU-2) acids for regeneration of hydrogen-cationite filters when justified.

31. The consumption of 100% acid PH, kg, per regeneration of a hydrogen-cationite filter shall bedetermined by the equation

P f H E acH c opH

H= 1000 , (16)

where aH is the specific acid consumption for regeneration of the cationite, g/g-eq, determined from Figure2 depending on the required filtrate hardness.

32. The volumes of the strong acid measuring tank and the tank for the dilute solution of acid (if itis diluted not before the filters) shall be sufficient for regeneration of one filter where there are up to fouroperating hydrogen-cationite filters, and for regeneration of two filters where there are more than four.

33. The equipment and pipes for dosing and transportation of acids shall be designed to observe thesafety rules for working with acids.

34. Removal of carbon dioxide from hydrogen-cationite water or from a mixture of hydrogen- andsodium-cationite water shall be performed in degassing units with acid-resistant ceramic packing measuring25 × 25 × 4 mm or with square wooden packing.

The transverse cross-sectional area of the degassing unit shall be determined to provide anirrigation density with ceramic packing of 60 m3/hr per m2 of degassing unit area, with wooden packing—40 m3/hr.

The fan of the degassing unit shall supply 15 m3 of air per m3 of water. Determination of thepressure developed by the fan shall be performed considering the resistance of the ceramic packing, taken

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as 30 mm water per m of height of the packing layer, and the resistance of the wooden packing—10 mm ofwater. Other resistances shall be taken as 30-40 mm of water.

Total salt content of initial water 20 g-eq/m3

Figure 2. Graph for determination of total hardness of water softened by hydrogen cationization.KEY: Vertical axis: Filtrate hardness, g-eq/m3; horizontal axis: Specific sulfuric acid consumption, g-eq, ofabsorbed cations Ca2+, Mg2+, and Na+

Table 5Content of (CO2) in water fed to Height of packing layer in degassing unit, m

degassing unit, g/m3 acid-resistant ceramic wooden1 2 350 3 4

100 4 5.2150 4.7 6200 5.1 6.5250 5.5 6.8300 5.7 7

The height of the packing layer required to reduce the content of carbon dioxide in the cationizedwater shall be determined from Table 5 as a function of the content of free carbon dioxide (CO2)fr, g/m3, inthe water fed into the degassing unit, as determined by the equation

(CO2)fr = (CO2)0 + 44A0, (17)where (CO2)fr is the content of free carbon dioxide in the initial water, g/m3;A0 is the alkalinity of the initial water, g-eq/m3.

35. When designing sequential hydrogen-sodium-cation water softening installations with“starvation” regeneration of the hydrogen-cation filters, the following shall be used:

a) filtrate hardness H fH , g-eq/m3, of hydrogen-cationite filters by the equation

( ) ( ) ( )H Cl SO NAfH

42

res+= + + −− − A , (18)

where (CL–) and (SO42−

) are the content of chlorides and sulfates in the softened water, g-eq/m3;

Ares is the residual alkalinity of the hydrogen-cationite filter filtrate, equal to 0.7-1.5 g-eq/m3;(Na+) is the sodium content in the softened water, g-eq/m3;

b) the consumption of acid for “starvation” regeneration of the hydrogen-cationite filters is 50 g perg-eq of carbonate hardness removed from the water;

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c) with “starvation” regeneration, the “conditional” exchange capacity of the cationites for the

HCO3−

ion (up to the moment when the alkalinity of the filtrate increases) for SK-1 sulfocarbon is 250-

300 g-eq/m3, for KB-4 cationite—500-600 g-eq/m3.36. To prevent acid water from entering the sodium-cationite filters in sequential hydrogen-sodium

cationization units, in the case where the hydrogen-cationite filters are regenerated with an excess aciddose, clarified unsoftened water shall be fed into the hydrogen cationite filter filtrate stream before thedegassing unit.

37. The equipment, pipes and fittings which contact acid water or filtrate shall be protected fromcorrosion or made of corrosion-resistant materials.

38. With parallel hydrogen-sodium cationization, ionite filters may when justified be provided withcounterflow regeneration or a stepwise counterflow ionization system may be used.

39. Spent regeneration solutions from ionite softening units, depending on local conditions, shall bedirected to accumulators, municipal or plant sewers; the possibility shall also be considered of treating theconcentrated portion of these waters for reuse.

Spent solutions shall be neutralized after blending as necessary before dumping into sewers. Thecalcium carbonate and magnesium dioxide precipitates produced shall be separated by settling and sent toan accumulator.

Clarified sodium chloride solutions (wastewater from regeneration of sodium cationite filters) shallbe reused for regeneration of sodium cationite filters (after neutralization if necessary).

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Appendix 8. Recommended. Freshening and Desalination of Water

Ion Exchange

1. Desalination of water by ion exchange shall be performed with a total salt content of the waterof up to 1500-2000 mg/L and a total content of chlorides and sulfates of not over 5 mg-eq/L.

Water fed to ionite filters shall contain not over: suspended matter—8 mg/L, color index—30° andpermanganate oxidizability —7 mg O/L.

Water which does not meet these requirements shall be pre-treated.2. Desalination of water by ion exchange in a single-stage system shall be performed by successive

filtration through a hydrogen cationite and weakly basic anionite with subsequent removal of carbondioxide from the water in degassers.

The salt content of water treated in a single-stage system shall be no more than 20 mg/L(conductivity 35-45 µohm/cm), without reducing the silicon content.

3. A two-stage desalination system shall include: hydrogen-cationite first-stage filters; anionitefirst-stage filters, charged with weakly basic anionite; hydrogen-cationite second-stage filters; degassers toremove carbon dioxide; anionite second-stage filters charged with strongly basic anionite to remove silicicacid.

The salt content of water treated in a two-stage system shall be not over 0.5 mg/L (conductivity1.6-1.8 µohm/cm) and silicic acid content not over 0.1 mg/L.

4. A three-stage desalination system, in addition to the items indicated in Paragraph 3, shall includea third-stage filter with a mixed charge consisting of a highly acid cationite and highly basic anionite(mixed-action filter—MAF).

The salt content of water treated in a three-stage system shall not exceed 0.1 mg/L (conductivity0.3-0.4 µohm/cm) and the silicic acid content shall not exceed 0.02 mg/L.

5. The hydrogen-cationite filters of the first stage shall be designed in accordance with theinstructions of Paragraphs 26 and 27 of Appendix 7, the degassers—in accordance with Paragraph 34 ofAppendix 7.

When justified, the hydrogen-cationite filters of the first stage may be equipped with counterflowregeneration or a stepwise-counterflow ionization system.

6. The following characteristics shall be used in the second-stage hydrogen-cationite filters:filtration speed up to 50 m/hr; cationite layer height—1.5 m; specific consumption of 100% sulfuric acid—100 g/g-eq of absorbed cations; sulfocarbon absorption capacity—200 g-eq/m3, KU-2 cationite absorptioncapacity—400-500 g-eq/m3; consumption of water for washing of cationite after regeneration—10 m3/m3

of cationite. Washing shall be performed with water which has passed through the first-stage anionitefilters.

Water from washing of second-stage cationite filters shall be used to loosen the hydrogen-cationitefirst-stage filters and prepare them for the regeneration solution. The regeneration and washing time of thehydrogen-cationite filters in the first stage shall be 2.5-3 hr.

7. The filtration area F1, m2, of the anionite first-stage filters shall be determined by the equationF1 = Q1/nrT1v1, (1)

where Q1 is the throughput of the first-stage anionite filters, including the consumption of water for theinternal needs of subsequent stages of the facility, m3/day;nr is the number of regenerations of the anionite first-stage filters per day, taken as 1-2;v1 is the design filtration speed, m/hr, no less than 4 and no more than 30;T1 is the operating time of each filter, hr, between regenerations, determined by the equation

T1 = 24/nr –τr, (2)

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where τr is the total duration of all filter regeneration operations, taken as 5 hr (loosening 0.25 hr,regeneration 1.5 hr, anionite washing 3-3.25 hr).

The volume of anionite in the anionite first-stage filters W1 shall be determined by the equationW1 = Q1C0/nrEr, (3)

where C0 is the total content of sulfate, chloride and nitrate ions in the initial water, g-eq/m3;Er is the operating exchange capacity of the anionite with respect to anions of the indicated strong acids, g-eq/m3 of anionite, taken from the manufacturer’s data; if such data are not available, a figure of 600-700 g-eq/m3 may be used for AN-31 and AV-17 anionites.

8. Regeneration of first-stage anionite filters shall be performed with a 4% calcined soda solution;the specific soda consumption shall be taken as 100 g Na2CO3 per g-eq of absorbed anions.

In facilities with second-stage anionite filters, charged with a strongly basic anionite, it ispermissible to regenerate the first-stage anionite filters with a spent caustic soda solution after regenerationof the second-stage anionite filters.

Regeneration solutions of soda and caustic soda shall be prepared using hydrogen-cationized water.Washing of first-stage anionite filters after regeneration shall be performed using hydrogen-

cationized water with a consumption of 10 m3/m3 of anionite.9. Second-stage anionite filters shall be charged with strongly basic anionite with a layer height of

1.5 m, filtration speed 15-25 m/hr.The silicon content of the strongly basic ionite shall be taken from manufacturer’s data or, if such

data are not available, from the table below.

Strongly basicanionite

Silicate capacity, g-eq/m3, with anionite exhausted to the point

of “breakthrough” of SiO32− into the filtrate, mg/L

Minimum residual

SiO32− capacity of

filtrate, mg/L0.1 0.5 1

AV-17 420 530 560 0.05Regeneration of highly basic anionite in second-stage filters shall be performed with a 4% caustic

soda solution. The specific consumption of 100% caustic soda shall be taken as 120-140 kg/m3 of anionite.10. For mixed-action filters, use: filtration speed—40-50 m/hr, cationite and anionite layer

heights—0.6 m each.The number of filters shall be no less than three, two operating, the third—in regeneration or in

reserve.Regeneration of mixed-action filters shall be performed after 10-12 thousand m3 of water per m3 of

ionite mixture have been filtered through the charge.The consumption of 100% sulfuric acid for regeneration of 1 m3 of cationite shall be taken as 70

kg, of 100% caustic soda for regeneration of 1 m3 of anionite—100 kg.11. Ion-exchange water desalination units shall provide for mutual neutralization of acid and alkali

waste waters from the regeneration of filters and, where necessary, additional neutralization with lime afterthey are mixed.

No less than two neutralization tanks shall be provided, each having a capacity equal to the dailyquantity of waste water. Water used for loosening and washing of ionites shall be reused.

Neutralization waste waters from regeneration of ionite filters shall be directed, depending on localconditions, into municipal or industrial sewers or accumulators.

Electrodialysis

12. The method of electrodialysis (electrochemical method) shall be used to freshen groundwaterand surface waters with salt content from 1500 to 7000 mg/L to obtain water with salt content no less than

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500 mg/L. When it is necessary to produce water with lower salt content, desalination of water by ionexchange shall be performed after electrodialysis. In individual cases, with justification, electrodialysis maybe used to freshen water with salt content up to 10,000-15,000 mg/L.

13. Water fed to electrodialysis freshing units shall contain not over: suspended matter—1.5 mg/L;color index—20°; permanganate oxidizability—5 mg O/L; iron—0.05 mg/L; manganese—0.05 mg/L;borates, as BO2—3 mg/L; bromine 0.4 mg/L.

Water which does not meet these requirements shall be pre-treated.The need for preliminary softening of freshened water with total hardness over 20 mg-eq/m shall be

demonstrated.Before water which has been freshened by electrodialysis is fed into a drinking water supply

system, it shall be subjected to deodorization on filters charged with active carbon and disinfected.14. The selection of the type of electrodialysis apparatus shall be based on the manufacturer’s data.

The number of freshening stages, number of parallel devices in each stage, number of recirculation cyclesand flow rate of discharged brine, as well as the voltage and current in the apparatus in all stages forpurposes of selecting a current converter shall be determined on the basis of the flow rate of freshenedwater and the salt content of the initial water.

Hydraulic calculations shall be used to determine the head loss in freshening chambers, internaldistribution and collection systems within the apparatus, and in dialysate and brine feed and drain pipes.

With a flow rate of freshened water of up to 250-400 m3/day, manufactured completeelectrodialysis freshening units shall be used, including the electrodialysis apparatus, dialysate and brineflow and recirculating loops with tanks and pumps, electric power supply and monitoring and automaticcontrol module.

15. A direct-flow multistage water freshening system with brine recirculation is recommended.Depending on the salt content of the freshened water in a direct-flow multistage unit it is permissible toprovide recirculation of dialysate and a mixing tank for dialysate and incoming water.

16. The number of freshening stages z of direct-flow installations shall be determined bycalculation

C C C C Cr

z

init init

stage 1

r2

init

stage 2

rz

init

stage

fr→ → → →α α α

Here

α r init frzC C≤ . (4)

where Cinit is the salt content of the initial water, mg-eq/L;Cfr is the salt content of the freshened water, mg-eq/L;αr is the maximum reduction in salt content of the dialysate in each freshening stage, taken as

αr = (100 – Ss)/100, (5)where Ss is the salt removal in one pass of the water through the apparatus, taken from the manufacturer’sdata, %.

17. The number of parallel operating apparatus Nap in each stage shall be determined by theequation

Nap = 26.8q(Cin – Cout)io Fm ηnc, (6)where q is the throughput of the unit, m3/hr;Cin is the dialysate concentration input to the equipment of each stage (for the first stage it is equal to thesalt content of the initial water), mg-eq/L;Cout is the concentration of the dialysate output by the equipment of the same stage (for the last stage it isequal to the salt content of the freshened water), mg-eq/L;io is the operating current density, A/cm2;

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Fm is the operating (net) area of each membrane, cm2;η is the yield per unit of current, which for apparatus using membranes of type MA-40 and MK-40 is 0.85;Nc is the number of cells in the apparatus, which is not over 200-250.

18. The operating current density io in the apparatus of each stage shall be taken as equal to the

optimal operating current density ioopt , determined by technical-economic calculations. The operating

current density in the apparatus of each stage shall be taken not over the limiting current density determinedby the equation

i C v p Klim d= ′ ′ ′ , (7)

where Cd is the calculated dialysate concentration in the freshening chamber, determined by the expressionCd = (Cin – Cout)/2.3 log(Cin/Cout), (8)

where v′ is the speed in the freshening chamber (average over free cross section), cm/s;K′, p′ are coefficients representing the depolarization properties of the separator-turbulizer used inapparatus of the type in question.

The operating current densities of the stages of the direct-flow multistage installation aredetermined by the equation

i i i i i io o o o o o s1 2 2 3 3 i= = = = 1 α , (9)

where io1is the operating current density on the first-stage apparatus;

i i io o o2 3 4, , , etc. are the operating current densities on the apparatus of stages 2, 3, 4 and others.

19. To determine the voltage on the electrodes of the apparatus in all stages (to select the type ofcurrent converter) it is necessary to consider: the voltage drop across the electrode system, the voltage dropin the membrane pack due to the resistance (the inverse of conductivity) of the solutions and membranes,and the total membrane potential considering concentration polarization. Calculations shall be performedfor the assigned solution temperature.

The conductivity κt of the dialysate and brine shall be determined by nomogram as a function of

the ratio of sulfate content SO42−

to the total content of anions ΣA, temperature ts and salt concentration

Ss (see figure).20. The brine concentration at the output of the last stage shall be no greater than the limiting

concentration determined from the condition of nonprecipitation of calcium sulfate compounds (the productof the active concentrations of sulfates and calcium in the brine shall not exceed the product of thesolubility of calcium sulfate at the temperature of the brine in the apparatus).

The calculated brine concentrations in each stage shall be determined as is the concentration in thedialysate. The brine concentration at the input to and output from the apparatus, as well as the number ofrecirculation cycles of brine, shall be determined on the basis of balance calculations.

21. Prevention of salt deposits on membrane surfaces from the brine loop and in the cathodechamber shall be assured by swapping the polarity of electrodes with simultaneous switching of brinedialysate loops, as well as acidification of the brine and catholyte.

The acid dose shall be taken equal to the alkalinity of the initial water.It is permissible with justification to wash out loops periodically with an elevated acid dose.22. The pipes of freshening units shall be of polyethylene, fittings—lined with polyethylene or

enameled.23. Each loop of a direct-flow unit shall be monitored for flow rate, temperature, salt content and

pH.24. In units with throughput over 400 m3/day, the control and monitoring equipment shall be set up

in a separate room, isolated from the electrodialysis equipment room.

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Example. Given: C = 40 mg-eq/L; [ SO42]/ΣA = 0.2; t = 10°C.

Answer: κt103 = 30 m–1⋅ohm–1: κt = 3⋅10–3 ohm–1⋅cm–1[SO4]/A(mg-eq/L)/(mg-eq/L)

KEY: Cs, mg-eq/L κt 103, ohm–1⋅cm–1

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Appendix 9. Recommended. Processing of Wash Water and Sediment at Water Treatment Plants

Wash Water Tanks

1. Wash water tanks shall be provided at water treatment plants with settling and subsequentfiltration to receive water from washing of filters for its uniform transfer without settling into pipes beforemixers or into the mixers.Note: It shall be possible to drain water into these tanks from above the sediment in settling tanks whenthey are emptied.

2. The number of tanks shall be no less than two. The volume of each tank shall be determined bythe schedule of delivery and uniform transfer of wash water and shall be no less than the volume of waterused in one filter washing operation.

3. The pumps and pipes used to transfer wash water shall be tested for operation of the filters inforced mode.

Wash Water Settling Tanks

4. Wash water settling tanks shall be provided with single-stage filtration (filters, contact clarifiers)and deferrization of water.

5. Wash water settling tanks, pumps and pipes shall be designed for periodic delivery of washwater, settling and uniform transfer of clarified water into pipes before mixers or into the mixersconsidering the requirements of Paragraph 3.

The accumulated sediment shall be sent to thickeners for additional consolidation or to a sedimentdewatering facility.

6. The wash water settling time for non-reagent deferrization plants shall be 4 hr, for waterclarification and reagent deferrization plants—2 hr.Note: When polyacrylamide is used in a dose of 0.08-0.16 mg/L the settling time shall be reduced to 1 hr.

7. When determining the volume of the sediment accumulation zone in settling tanks the moisturecontent of the sediment shall be taken as 99% for water clarification and reagent deferrization plants and96.5% for non-reagent deferrization plants.

The total sediment accumulation time with repeated periodic filling of settling tanks shall be takenas no less than 8 hr.

Thickeners

8. Thickeners with slow mechanical agitation shall be used to accelerate consolidation of sedimentfrom horizontal and vertical settling tanks, clarifiers, reagent sections and sediment from wash watersettling tanks at water treatment plants with mean annual initial water turbidity up to 300 mg/L.Note: With justification, sediment may be sent to dewatering facilities without preliminary consolidation inthickeners.

9. Thickeners shall have the following characteristics: diameter—up to 18 m; mean workingdepth—at least 3.5 m; bottom slope toward central well—8°; rotating beam—with vertical triangular orcircular blades and scrapers to move the consolidated sediment toward the central well; lateral surface areaof blades—from 25 to 30% of the cross-sectional area of the agitated sediment volume; blade tops—at alevel equal to half of the water depth at the center of the rotating beam; sediment feed into thickener—periodic according to schedule of sediment removal from facilities; sediment input—1 m above the level ofthe bottom at the center of the thickener; clarified water outlet—through devices not dependent on waterlevel in thickeners (through floating hose, etc.).

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10. The duration of the sediment thickening cycle shall be determined based on the total time of thefollowing operations: filling of thickener—10 to 30 min depending on time required to remove sedimentfrom facility; thickening—based on process studies or similar water treatment plants, or if such data arenot available, from the table below; successive transfer of clarified water and of thickened sediment—30 to40 min.

Transfer of sediment shall be performed after several thickening cycles.11. The maximum speed of movement of the rotating beam and average moisture content of the

sediment after thickening shall be determined by process testing, or if no testing has been performed, fromthe table.

Characteristics of treated water andtreatment method

Maximum speedof end of rotating

beam, m/s

Length ofthickening cycle,

hr

Mean sedimentmoisture content

at outlet fromthickener, %

Low-turbidity water treated withcoagulant

0.015 10 97.7-98.2

Medium-turbidity water treated withcoagulant

0.025 8 96.8-97.3

Turbid water treated with coagulant 0.03 6 85.5-91.8Softening with magnesium hardness upto 25%

0.025 5 80-82.7

Softening with magnesium hardnessover 25%

0.015 8 87.3-90.9

Deferrization, no reagents used 0.015 8 91.4-93.2Deferrization with reagents (coagulant,lime, potassium permanganate, etc.)

0.025 10 96.8-97.7

12. The volume of the thickener Wth, m3 shall be determined from the equationWth = 1.3Kd.s. Ws.p. , (1)

Kd.s. is the sediment dilution factor as it is drained from water treatment facilities, taken from Paragraph6.74; Ws.p. —volume of sediment portion of water treatment facility, m3.

13. The number of thickeners shall be determined in order to support periodic reception of sedimentin accordance with the mode of its removal from facilities and the length of the thickening cycle.

14. At single-stage filtration and deferrization plants, thickeners may be used as wash watersettling tanks.

15. Feeding of sediment to thickeners shall generally be by gravity flow. It is recommended thatmontejus (air lift) or plunger-type pumps be used to transfer the thickened sediment to mechanicaldewatering facilities.

16. Hydraulic design of pipes shall be performed considering the properties of the sediment to betransported.

Accumulators

17. Accumulators shall be provided for dewatering and storage of sediment with removal ofclarified water and the water extracted during consolidation. The design period for transfer of sediments toan accumulator shall be no less than five years.

Accumulators shall be gullies, worked-out mines or leveled areas surrounded by soil embankmenton a natural base with a depth of at least 2 m. If the sediment contains toxic substances, antiseepagescreens shall be provided in accumulators.

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18. The volume of an accumulator Wacc, m3, shall be determined by the equationWacc = 0.876qCs/[1/(100 – Ps1)ρ1 + 1/(100 – Ps2)p2 + ... + 1/(100 – Psnρn], (2)

where q is the design water flow of the water treatment plan, m3/hr;Cs is the mean annual concentration of suspended matter in the initial water, g/m3, determined from

equation (11) of Paragraph 6.65; Ps1, Ps2, ..., Psn are the mean values of moisture content in percent, and ρ1,ρ2, ..., ρn of density, metric ton/m3 of the sediment during years one, two, ... n of consolidation of thesediment, taken from the data on operation of accumulators under similar conditions, or if no such data areavailable, from Figures 1 and 2.

19. The number of sections of an accumulator shall be no less than two operating in alternateyears, with sediment placed in one segment for one year with removal of clarified water. Dewatering andconsolidation of the sediment will occur in previous sections, with freezing in the winter and drying in thesummer with removal of the water released upon consolidation.

20. Devices for feeding sediment and draining water shall be provided on opposite sides ofaccumulators.

The distance between devices for feeding sediment shall be no less than 60 m.The design of devices for draining water shall provide for its drainage from any level through the

depth of the accumulators.

Sediment consolidation time Tc, yr.Figure 1. Mean moisture content and density of

sediment from clarification and decoloration plantswith multiple-year consolidation.

Quantity of suspended matter in initial water—M,mg/L; reagents—R1—M < 50; R—Al2(SO4)3; 2—M < 50; R—Al2(SO4)3 +surfactant; 3—M < 50; R—Al2(SO4)3 + surfactant +Ca(OH)2; 4—M = 50-250; R—Al2(SO4)3; 5—M = 250-1000; R—Al2(SO4)3; 6—M = 1000-1500; R—Al2(SO4)3; 7—M > 1500; R—surfactant; or treatmentwithout reagents. KEY: Vertical axis: Moisture contentPsed, %; middle of figure: : Density ρ, metric ton/m3

Note: Solid lines show moisture content, dotted linesshow density.

Sediment consolidation time Tc, yr.Figure 2. Mean moisture and density of sediment

from deferrization or reagent softening plants withmultiple-year consolidation.

1—reagent deferrization; 2—non-reagent deferrization;3—reagent softening with magnesium hardness over25%; 4—reagent softening with magnesium hardnessless than 25%.KEY: Vertical axis: Moisture content Psed, %; middle offigure: : Density ρ, metric ton/m3

Note: Solid lines show moisture content, dotted linesshow density.

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Freezing Sites

21. Freezing sites for dewatering of sediment shall be provided in regions with a continuous freezeperiod of no less than two months with subsequent sediment transferred at intervals of 1-3 years to storagesites.

22. The total area of freezing sites Ff.a., m2, shall be determined by the equationFf.a. = Fsp + Fs.f. + Fw, (3)

where Fs, Fs.f., Fw are the areas of the sites, m2, determined from the surface of the sediment when the site isfilled to half depth for the spring, summer-fall and winter periods of sediment discharge.

23. The usable area of sites for spring and summer-fall shall be determined in order to form asediment layer equal to the freezing depth Hfr, m, as determined by the equation

H tfr = 0 017. ,Σ (4)

where Σt is the sum of absolute negative mean daily air temperatures during the winter freeze, °C, based ondata from the nearest weather station.Note: Depending on local conditions and dimensions of sites, they may be divided into sections.

24. The volume of consolidated sediment Wss.s.f. , m3, in areas where sediment is placed in the

spring and summer-fall, shall be determined by the equation

Wssp.s.f.

= 24⋅10–4qCs Tst /(100 – Ps)ρ,(5)

where q is the calculated flow rate of water through the treatment plant, m3/hr;Cs is the average concentration of suspended matter in the water for the design period, g/m3, determinedusing equation (11) of Paragraph 6.65;Tc is the length of the design period, in days, using: for the spring period—from the end of the stable freezeto the onset of the period of positive temperatures (1 month after the mean air temperature rises above 0°Cfor areas with stable freeze duration less than 3 months and 2 months for areas with stable freeze durationover 3 months); for the summer-fall period—up to the onset of the stable freeze;Ps, ρ are the mean moisture content in percent and density, metric ton/m3, of the sediment in the spring orsummer-fall periods, taken from Figures 3, 4, 5 and 6 as a function of the consolidation time of thesediment, determined from the middle of the spring or summer-fall periods to the onset of the period ofstable freeze.

25. The usable area of a site for winter discharge shall be determined to contain the volume ofsediment arriving during the period of stable freeze, without accounting for consolidation of the sedimenton the site.

The area for winter discharge of sediment shall be divided into sections.

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Sediment consolidation time Tc, mo.

Density ρ, metric ton/m3

Figure 3. Mean moisture content of sediment at waterclarification and decoloration plants with consolidation

up to one year.Quantity of suspended matter in initial water—M, mg/L;

reagents, R1—M < 50; R—Al2(SO4)3; 2—M < 50; R—Al2(SO4)3 +surfactant; 3—M < 50; R—Al2(SO4)3 + surfactant + Ca(OH)2;4—M = 50-250; R—Al2(SO4)3; 5—M = 250-1000; R—Al2(SO4)3; 6—M = 1000-1500; R—Al2(SO4)3; 7— M > 1500;R—surfactant or non-reagent treatmentKEY: Vertical axis: Moisture content Psed, %

Figure 5. Density as a function of moisture content ofsediment from clarification and decolorization plants.Quantity of suspended sediment in initial water—M, mg/L;

reagents—R: 1—M < 50; R—Al2(SO4)3; 2—M < 50; (M =50-250); R—Al2(SO4)3 + surfactant; R—Al2(SO4)3; 3—M =250-1000; R—Al2(SO4)3; 4—M = 1000-1500; R—Al2(SO4)3

KEY: Vertical axis: Moisture content Psed, %

Sediment consolidation time Tc, mo. Density ρ, metric ton/m3

Figure 4. Mean moisture content of sediment at waterdeferrization and reagent softening plants with

consolidation up to one year.1—reagent deferrization; 2—non-reagent deferrization; 3—reagent softening with magnesium hardness over 25%; 4—reagent softening with magnesium hardness less than 25%.KEY: Vertical axis: Moisture content Psed, %

Figure 6. Density as a function of moisture content ofsediment from deferrization and reagent softening

plants.1—reagent softening of water with magnesium hardness over25%; 2—reagent softening of water with magnesium hardnessless than 25%; 3—reagent and non-reagent deferrization ofwater KEY: Vertical axis: Moisture content Psed, %

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The area of one section shall be determined as a function of the volume of sediment dischargedfrom the facilities and a sediment thickness Hd for a single discharge of 0.07-0.1 m.

The number of sections shall be determined as a function of the time required to freeze through thesediment depth selected and the number of discharge cycles of sediment from facilities during the freezingtime.

The design air temperature used to determine the freezing time of a sediment layer (Figure 7) shallbe determined for the month with the highest mean daily temperature during the period of stable freeze.

Figure 7. Freezing depth of a sediment layer as a function of mean daily air temperature and freezing time.KEY: Vertical axis: Hd, m t, °C; horizontal axis: τfr, days

The depth of sediment in each section of the winter discharge site Hwin, m, shall be determined asthe sum of the sequentially frozen layers of sediment during the period of stable freeze:

Hwin = Hd nd, (6)where nd is the number of sediment discharges per section during the period of stable freeze, determinedfrom the equation

nd = Kfr S/τfr, (7)where Kfr is a coefficient considering incomplete usage of the period of stable freeze, taken as 0.8;S is the number of days during the period of stable freeze;τfr is the freezing time of a sediment layer in days, determined from Figure 7 as a function of the mean dailynegative air temperature t, °C, for each month of the period of stable freeze.

26. Freezing sites may be planned where the water table depth is no less than 1.5 m below the baseof the site.

When necessary, devices shall be provided to carry away groundwater and surface water.27. Feeding of sediment onto sites and sections shall be through pipes.Discharge of sediment onto sites and sections shall be in open ditches along their longer sides. The

slope of the ditches shall be no less than 0.01.Dumping of sediment onto sites (sections) and discharge of clarified water shall be performed on

opposite sides at distances of not over 40 m. The distance between sediment discharge devices, and alsobetween clarified water drainage devices, shall be not over 30 m.

28. Sediment discharge devices shall not cause erosion of the base of the site or the layer of frozensediment.

Clarified water drainage devices shall permit water to be taken from any level of depth on the site.

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29. The structural height of the embankments around freezing sites (sections) Hstr, m, shall bedetermined by the equation

H N W F Hstr acc sa

f.s. y= + +0 2. , (8)

where Nacc is the number of years of accumulation of consolidated sediment;

Wsa is the annual volume of compacted sediment, m3, with moisture content 70%;

Ff.s. is the total area of freezing sites, m2;Hy is the layer of unconsolidated sediment, m, for the last year before the sediment is carried away.

Drying Sites

30. In southern areas, where the moisture deficit during the period of stable moisture deficit is 800mm or more, dewatering of sediment may be performed on drying sites by consolidation under the influenceof its own mass and drying in the open air with subsequent hauling of the sediment each 1-3 years tostorage sites.

The total usable area of sediment drying sites Fd.s., m2, shall be determined by the equationFd.s. = Fw.sp. + Fs, (9)

where Fw.sp. and Fs are the areas of drying sites for the winter-spring and summer discharge of sediment, m2.31. The usable area of sites for discharge of sediment in the winter-spring period Fw.sp., m2, shall be

determined by the equation

( )F W E Aw.sp. swsp

y a= −1000 0 75. , (10)

where Ey is the quantity of water evaporated in one year from the free surface of the water, mm;Aa is the annual amount of precipitation, mm;

Wsw.sp.

is the volume of sediment during the winter-spring period, m3, determined by the equation

W W Wsw.sp.

s w= ′ − , (11)

where ′Ws is the volume of sediment, m3, discharged onto the drying site during the winter-spring period

with average moisture content ′Ps , %;

Ww is the volume of water, m3, separated from the sediment as it is consolidated on the site, determined bythe equation

( ) ( )[ ]W W P Pw s s s= ′ − − ′ −1 100 100 , (12)

where Ps is the moisture content of the sediment compacted on the drying site during the winter-springperiod, as determined from Figures 3 and 4;

′Ps is the moisture content of sediment, %, taken for discharge of sediment from thickeners from the table

in Paragraph 11, from settling tanks and clarifiers using the equation

′Ps = 100(ρs – δ)/(ρs – δ + ρsδ), (13)

where ρs is the mean density of the solid phase in the sediment, varying from 2.2 to 2.6 metric ton/m3;δ is the concentration of solid phase in the sediment, metric ton/m3, taken from Table 19 of Paragraph 6.65considering the dilution of the sediment as it is discharged as described in Paragraph 6.74.

The value of Ey, mm, is determined by the equationEy = 0.15Td(l0 – l200)(1 + 0.72v200), (14)

where Td is the total number of days per year with a moisture deficit;l0 is the mean saturated water vapor pressure corresponding to the temperature of the sediment, millibars;

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l200 is the mean water vapor pressure corresponding to the absolute moisture content of the air at a heightof 200 cm above the water surface, millibars, taken from weather station data;v200 is the mean wind speed at 200 cm height, m/s.

32. The usable area of sediment discharge sites for the summer period shall be determined usingequation (10) of Paragraph 31, with the values of Ey and Aa taken as the average values over the period ofstable moisture deficit.

The time from the moment of discharge of the sediment onto the site to the beginning of removal ofwater from the sediment shall be taken as 4-5 days.

The volume of compacted sediment discharged in the summer shall be determined using equation(11) of Paragraph 31 similar to the winter-spring discharge, but using the moisture content and density ofthe sediment from Figures 3-6.

33. Depending on local conditions and drying site dimensions, the sites may be divided intosections.

Site discharge devices shall be designed in accordance with Paragraph 27.34. The structural height of embankments around drying sites shall be determined using equation

(8) of Paragraph 29.

Appendix 10. Obligatory. Hydraulic Design of Pipelines

1. The head loss in the pipelines of water supply and distribution systems is caused by thehydraulic resistance of the pipes and pipe joints, as well as valves and connectors (fittings).

Table 1No. Pipe type m A0 1000 A1 1000(A1/2

g)C

1 New steel without inside protectivecoating or with bitumen protectivecoating

0.226 1 15.9 0.810 0.684

2 New cast iron without insideprotective coating or with bitumenprotective coating

0.284 1 14.4 0.734 2.360

3 Not new steel and notnew cast iron withoutinside

v<1.2 m/s 0.30 1 17.9 0.912 0.867

protective coating orwith bitumen protectivecoating

v ≥ 1.2m/s

0.30 1 21.0 1.070 0

4 Asbestos cement 0.19 1 11.0 0.561 3.515 Reinforced concrete vibration-

hydraulic pressed0.19 1 15.74 0.802 3.51

6 Reinforced concrete centrifuged 0.19 1 13.85 0.706 3.517 Steel and cast iron with internal

plastic or polymer-cement coatingapplied by centrifuging

0.19 1 11.0 0.561 3.51

8 Steel and cast iron with internalcement-sand coating applied byspraying with subsequent smoothing

0.19 1 15.74 0.802 3.51

9 Steel and cast iron with internal 0.19 1 13.85 0.706 3.51

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cement-sand coating applied bycentrifuging

10 Plastic 0.226 0 13.44 0.685 111 Glass 0.226 0 14.61 0.745 1Note: The value of C is given for ν = 1.3⋅10–6 m2/s (water, t = 10°C).

2. Head losses per unit length of pipe (“hydraulic slope”) i, considering the hydraulic resistance ofjoints, shall be determined by the equation

i = (λ/d)(v2/2g) = (A1/2g)[(A0 + C/v)m/dm+1]v2, (1)where λ is the hydraulic resistance factor, determined by the equation

λ = A1(A0 + B0d/Re)m/dm = A1(A0 + C/v)m/dm, (2)d is the inside diameter of the pipe, m;v is the mean speed of movement of the water over the cross section, m/s;g is the acceleration of the force of gravity, m/s2;Re = vd/ν is the Reynolds number; B0 = CRe/vd;ν is the kinematic viscosity of the transported fluid, m2/s.

The values of the exponent m and coefficients A0, A1 and C for steel, cast iron, reinforced concrete,asbestos cement, plastic and glass pipes shall be taken, generally, as given in Table 1. These valuescorrespond to modern manufacturing techniques.

If the values of A0, A1 and C guaranteed by the manufacturer differ from those given in Table 1,they shall be indicated in the GOST or specifications for the pipe.

3. Without stabilization treatment of water or effective internal protective coatings, the hydraulicresistance of new steel and cast iron pipes rapidly increases. Under these conditions the equations fordetermination of head loss in new steel and cast iron pipes shall be used only for verification calculationwhen it is necessary to analyze the operating conditions of water supply systems during their initial periodof operation.

Steel and cast iron pipes shall generally be used with interior polymer-cement, cement-sand orpolyethylene protective coatings. Where they are used without such coatings and there is no stabilizationtreatment, a correcting factor (not over 2) shall be added to the values of A1 and C from Table 1 and to thevalue of K from Table 2, the value of this factor being based on data on the increase in head loss in pipesoperating under similar conditions.

4. The hydraulic resistance of connecting parts (fittings) shall be determined from reference books,the hydraulic resistance of valves—from the manufacturers information.

If data are not available on the number of connecting parts (fittings) and valves installed onpipelines, the head loss may be increased by an additional 10-20% over the values for the pipes.

5. In technical and economic calculations and hydraulic calculations for water supply anddistribution systems performed on computers, it is recommended that head losses in pipes be determined bythe equation

i = Kqn/dp, (3)where q is the design flow rate of water, m3/s;

d is the design inside diameter of the pipe, m.The values of coefficient K and the exponents n and p shall be taken from Table 2.

Table 2No. Pipe type 1000 K p n1 New steel without inside protective coating or

with bitumen protective coating1.790 5.1 1.9

2 New cast iron without inside protective coatingor with bitumen protective coating

1.790 5.1 1.9

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3 Not new steel and not new cast iron withoutinside protective coating or with bitumenprotective coating

1.735 5.3 2

4 Asbestos cement 1.180 4.89 1.855 Reinforced concrete vibration-hydraulic pressed 1.688 4.89 1.856 Reinforced concrete centrifuged 1.486 4.89 1.857 Steel and cast iron with internal plastic or

polymer-cement coating applied by centrifuging1.180 4.89 1.85

8 Steel and cast iron with internal cement-sandcoating applied by spraying with subsequentsmoothing

1.688 4.89 1.85

9 Steel and cast iron with internal cement-sandcoating applied by centrifuging

1.486 4.89 1.85

10 Plastic 1.052 4.774 1.77411 Glass 1.144 4.774 1.774

Old data information

Appendix 11. Recommended. Treatment of Cooling Water with Chlorine and Copper Sulfate

Cooling water treatmentPurpose of Chlorine Copper sulfate (as copper ion)chlorine

or copper sulfateDose,mg/L

Duration ofeach

chlorinationperiod, min, hr

Periods Dose, mg/L Duration ofeach

chlorination period

Periods Additionaldata

Control watercoloration incooling reservoirs(ponds)

— — — 0.1-0.5, pervolume ofupper 1-1.5m layer ofwater inreservoir orentirevolume ofwater inpond

Determinedbyexperimentduring use

— To convertcopper ion tocommercialproduct,multiply by 4

Prevent bacterialbiologicalovergrowth ofheat exchangeapparatus andpipes

— 40-60 min 2-6timesper day

— — — Chlorine doseto maintainresidual activechlorinecontent inwater returnfrom mostdistant heatexchanger at1 mg-L for 30-40 min

Prevent algaeovergrowth ofcooling towers,spray pools andheat exchange

— — — 1-2 1 hr 3-4timespermonth

—

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sprinklersPrevent biologicalovergrowth oftowers, spraypools and heatexchangesprinklers withmicroorganisms

7-10 1 hr 3-4timespermonth

1-2 1 hr 3-4timespermonth

—

Notes: Recommendations for treatment of water with copper sulfate do not extend to cooling reservoirs (ponds)used for fishing.Use of copper sulfate in circulating water supply system with towers, spray pools and heat exchange equipmentsprinklers for which water is discharged into bodies of water used for fishing is permitted if the MPC of copper forthese bodies of water is satisfied.

Appendix 12. Recommended. Design of Cooling Water Treatment Modes to Prevent Carbonate andSulfate Deposits

1. When water is acidified, the dose of acid Dacid, mg/L in the water added shall be determined by theequation

Dacid = 100eacid(Aadd – Acir/Kev)/Cacid, (1)where eacid is the equivalent weight of acid, mg/mg-eq, for sulfuric acid—49, for hydrochloric acid—36.5;Aadd is the alkalinity of the added water, mg-eq/L;Acir is the alkalinity of the circulating water, established when treating the water with acid, mg-eq/L;Cacid is the content of H2SO4 or HCl in the technical acid, %;Kev is the concentration (evaporation) factor of salts not precipitated into the sediment, defined as Kev = (P1

+ P2 + P3)/P2 + P3 = P/P2 + P3,where P1, P2, P3 are the water losses from the system to evaporation, the loss with wind and discharge(blowdown), %, and the circulating water flow.The alkalinity of the circulating water Acir shall be determined by the equation

( ) ( )( ) ( ) ( )A N N P P P P A P N P Pcir cool add dobCO CO= − + − + + − −01 484 100 44 0220 02

12

2 2 02

1. . . ,(2)

N K0 =ψ ev addCa( ) , (3)

where ψ is a quantity dependent on the total salt content of the circulating water, Scir, and the temperatureof the cooled water, t2, taken from Table 1;(Ca)add is the concentration of calcium in the water added, mg/L;(CO2)cool is the concentration of carbon dioxide in the water added, mg/L, taken from Table 2 as a functionof the alkalinity of the water added and the coefficient of evaporation of water in the system Kev;(CO2)add is the concentration of carbon dioxide in the water added, mg/L.The salt content of the circulating water Scir, mg/L, is determined by the equation

Scir = SaddKev, (4)where Sadd is the salt content of the water added, mg/L.When water is treated with acid, blowdown of the circulating water system need not be performed if theevaporation coefficient, with the water lost with the wind at the cooling tower and the water taken forprocess needs, does not reach a value causing an increase in the concentration of sulfates sufficient to causecalcium sulfate precipitation.

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Calcium sulfate does not precipitate in the circulating water system if the product of the active

concentrations of ions Ca2+ and SO42−

in the circulating water does not exceed the product of the

solubility of calcium sulfate

f C C Ki2

Ca SO ev2

CaSO4 4PR′ < , (5)

where fi is the activity of bivalent ions taken from Table 3 as a function of the µ-ionic strength of thesolution (cooled water), g-ion/L, determined by the equation

( ) ( )[ ]µ = ′ + + + + + ′K C C C C C Cev Cl HCO Na Ca Mg SO3 44 2/ , (6)

where C C C CHCO Na Mg Ca3, , , are the concentrations of bicarbonate, sodium, magnesium and

calcium ions in the water added, g-ion/L;

′ ′C CCl SO4, are the concentrations of chloride and sulfate ions in the acidified water added, g-ion/L, taken

as:with acidification by sulfuric acid

( )( )′ = ′ = +C C C C D CCl Cl SO SO acid acid4 4; / / ;98000 100 (7)

with acidification by hydrochloric acid

( )( )′ = + ′ =C C D C C CCl Cl acid acid SO SO4 4/ / ; ,36500 100 (8)

where CCl and CCO4are the concentrations of chloride and sulfate ions in the water added before

acidification, g-ion/L;Dacid is the dose of acid, mg/L, determined by equation (1);PR CaSO4

is the solubility product of calcium sulfate (a constant) at the water temperature 25-60°C, taken

as 2.4⋅10-5.If the condition specified in equation (5) is not maintained without circulating water system blowdown, it isnecessary to perform blowdown, the value of which assures that the condition is met.

2. In recarbonization the dose of carbon dioxide DCO2, mg/L, computed for the circulating water

flow, shall be determined using the equation

( ) ( )( ) ( )D A K v N P PCO add 2 acid 2 add2e CO CO= − − −/ / / .0

2 100 100 100

(9)Introduction of stack gases cleansed of ash or gaseous carbon dioxide to the circulating water shall beperformed using gas blowers through bubbler tubes or water spray ejectors. The consumption of stackgases qsg, m3/hr, at normal atmospheric pressure of 0.1 MPa (1 kgf/cm2) and temperature 0°C shall bedetermined by the equation

q D q Csg CO cool CO use2 2= 104 / ,β γ (10)

where qcool is the flow rate of circulating water, m3/hr;CCO2

is the content of CO2 in the stack gases, % by volume, determined by stack gas analysis.

SN

iP2.04.02-84

160

Table

1C

ooledw

atertem

pera-ture,t2 ,°C

Ionicstrength

ofsolution

(cooledw

ater)µ,g-ion/L

0.00494090.009882

0.01482320.0197643

0.02470550.0365233

0.05480140.0666192

0.08220210.094019

0.10960280.1214206

0.13700350.1488213

0.164[ ill.]

Saltcontentofcooled

water*

,Scir ,m

g/L200

400600

8001000

15002000

25003000

35004000

45005000

55006000

58.29

8.969.49

9.9310.32

11.1112.1

12.6513.29

13.7414.28

14.715.13

15.4715.89

108.09

8.759.26

9.6910.07

10.8411.81

12.3412.97

13.4113.93

14.3514.76

15.115.5

157.82

8.478.96

9.389.75

10.4911.42

11.9412.55

12.9713.48

13.8914.29

14.6115

207.53

8.148.62

9.029.37

10.0910.99

11.4912.07

12.4812.98

13.3513.74

14.0514.43

257.18

7.768.22

8.68.94

9.6210.48

10.9611.51

11.912.37

12.7413.1

13.413.76

306.83

7.397.82

8.188.5

9.159.97

10.4210.95

11.3211.77

12.1212.47

12.7513.09

356.38

6.97.31

7.647.95

8.559.31

9.7410.23

10.5810.99

11.3211.65

11.8112.23

405.91

6.396.76

7.087.36

7.928.62

9.029.47

9.7910.18

10.4810.78

11.0311.32

Table

2A

lkalinityof

addedw

ater,A

add ,mg-eq/L

Evaporation

coefficientK

ev

1.21.5

22.5

31.2

1.52

2.53

Values

of(C

O2 )cool

inw

atercooled

incooling

tower,m

g/L.W

ithacidification

With

decarbonation1

—0.6

0.60.5

0.50.2

0.70.9

1.52.4

22.2

2.12.1

22

1.83.3

6.912

18.93

3.62.8

2.52.3

2.26

1026

3436

45.3

4.63.8

3.53.4

1228

3640

435

96.4

5.14.5

4.334

3640

——

616.3

97.6

65.4

——

——

—O

lddata

information

Note:

With

coolingofw

aterin

spraytow

ersand

coolingreservoirs

(ponds),thevalues

of(CO

2 )cool shallbebased

onprocess

testdata.T

able3

Old

datainform

ationIonic

strengthof

solution(cooling

water)µ,g-ion/L

0.010.02

0.030.04

0.050.06

0.070.08

0.090.1

0.110.12

0.130.14

0.150.16

Bivalention

activity0.67

0.580.53

0.50.47

0.450.43

0.410.39

0.380.36

0.350.34

0.320.31

0.3

*Translator’s

note:sic;probably:circulatingw

ater;seeE

quation(3).

SNiP 2.04.02-84

161

When these data are not available, the CO2 content in the stack gases may be accepted as, forburning of: coal—5-8%, petroleum and fuel oil—8-12%; blast furnace gas—15-22%; when pure gaseouscarbon dioxide is added to the water, CCO2

is taken as 100%;

βuse is the utilization of the carbon dioxide, %, taken when it is added to the water by water-sprayejectors as 40-50%, by gas blowers and bubbler tubes— 20-30%;

γ is the volumetric weight of the stack gases at normal atmospheric pressure and at a temperatureof 0°C, gf/m3 (when the actual data are not available, 2000 gf/m3 may be used).

When stack gases or gaseous carbon dioxide are introduced to the circulating water by means ofgas blowers and bubbler tubes, they shall be placed beneath a water layer of at least 2 m. When water-spray ejectors are used, a portion of the circulating water shall be saturated with the stack gases or carbondioxide, then mixed with the entire volume of water.

The quantity of water zcir, % of the total circulating water flow, to be passed through the water-spray ejectors shall be determined by the equation

z D M Ccir CO CO CO use2 2 2= 106 / ,β (11)

where MCO2is the solubility of carbon dioxide in the water, mg/L, at the given temperature and a partial

pressure of 0.1 MPa (1 kgf/cm2), taken from Table 4.

Table 4Watertemperature,°°°°C

10 15 20 25 30 40 50 60

Carbondioxidesolubility,mg/L

2310 1970 1690 1450 1260 970 760 580

Old data informatinDevices for dissolution of carbon dioxide in water and transportation of water saturated with carbondioxide shall be made of corrosion-resistant materials.

When calculating the dose of carbon dioxide using equation (9), the blow-through amount P3 shallbe set and the amount of water added P shall be determined.

If with a given blow-through the value of z obtained is found to be undesirable based on technical-economic calculations, the blow-through P3 shall be increased or another method used to stabilize thewater—acidification or phosphatizing.

3. The concentration of phosphate reagent (sodium tripolyphosphate or hexametaphosphate asP2O5) in the circulating water shall be maintained at 1.5-2 mg/L. The necessary reagent dose, depending onthe flow of water added, shall be 1.5-2.5 mg/L as P2O5 or 3-5 mg/L as the commercial product.

When water is phosphate treated to prevent scale formation, the amount of blow-through P3, %,shall be determined by the equation

P3 = P1/(Kev.per – 1) – P2, (12)where Kev.per is the permissible evaporation coefficient of the water, determined by the equation

Kev.per = (2 – 0.125Aadd)(1.4 – 0.01t1)(1.1 – 0.01Hadd), (13)where t1 is the temperature of the circulating water before the cooler, °C;Hadd is the hardness of the water added, mg-eq/L.The values of P1 and P2 shall be accepted in accordance with Paragraph 11.9. The method of phosphatizingshall be used where Kev.per > 1 and values of blow-through are judged acceptable on the basis of technical-economic calculations. With values of Kev.per < 1, acidification or combined phosphate-acid treatment of thewater shall be used.

SNiP 2.04.02-84

162

4. With combined phosphate-acid treatment of water the acid dose Dacid, mg/L, calculated for theflow of water added, shall be determined by the equation

Dacid = 100eacid(Aadd – Aadd.lim)/Cacid, (14)where Aadd.lim is the limiting value of alkalinity of the added water, mg-eq/L, for which prevention ofcarbonate deposits under the conditions at hand (t1, Kev and Hadd) can be achieved by phosphatizing, asdetermined by the equation

Aadd.lim = 16 – Kev/0.125(1.4 – 0.1t1)(1.1 – 0.01Hadd). (15)The method of combined phosphate-acid treatment of water shall be used where

0 < Aadd.lim < Aadd. (16)Where Aadd.lim > Alim only phosphatizing shall be used, where Aadd.lim < 0—acidification.The dose of phosphate reagent (sodium tripolyphosphate or hexametaphosphate) shall be taken as 3-5 mg/Las the commercial product as calculated for the flow rate of added water and refined in the process ofoperations.

APPENDIX 13. RECOMMENDED. INTERIOR FINISH OF ROOMS

ItemNo.

Building orRoom

Content of Finishing Work

Walls Ceilings FloorsProduction Rooms

1 Drum screen andmicrofilter room

Point seams of panel walls. Plasterbrick walls. Coat with moisture-resistant paints

Coat with moisture-resistant paints.

Cement

2 Reagentmanagementa) rooms withnormal humidity

Point seams of panel walls. Laybrick walls with notched seams.Coat with calcimine

Sized whitewash Cement

b) rooms withelevated humiditywith open watercontainers

Point seams of panel walls. Coatwith moisture-resistant paints.

Coat with moisture-resistant paints

Ceramic tiles

3 Dry reagentstorehouses

Point seams of panel walls. Laybrick walls with notched seams.Limewash

Limewash Cement

4 Chlorine meteringroom

Point seams of panel walls. Plasterbrick walls. Face with glazed tiles toa height of 2 m, and above that, coatwith three layers of hot paraffin orperchlorovinyl enamels

Coat with three layersof hot paraffin orperchlorovinylenamels

Ceramic acid-resistant tiles, acid-resistant asphalt, oracid-resistantconcrete tiles

5 Chlorinestorehouse

Point seams of panel walls. Plasterbrick walls. Round wall joints withfloor and ceiling. Coat with threelayers of hot paraffin or perchloro-vinyl enamels.

Coat with three layersof hot paraffin orperchloro-vinylenamels

Acid-resistantasphalt with asmooth surface oracid-resistantconcrete tiles

6 Blower station –machine room

Point seams of panel walls. Plasterseams of panel walls. Coat withwater-emulsion paints to a height of1.5 m, and above that, withcalcimine

Sized whitewash Ceramic tiles.Concrete tiles on theerection site

SNiP 2.04.02-84

163

ItemNo.

Building orRoom

Content of Finishing Work

Walls Ceilings Floors7 Filter, clarifier,

and contactclarifier room

Point seams of panel walls. Plasterbrick walls. Face walls adjoiningfilter and clarifier service platformswith glazed tiles to a height of 1.5 mfrom the platform floor, and abovethat, coat with moisture-resistantpaints. Face interior walls of filtersand contact clarifiers with glazed tilefrom their top to a level 15 cm belowthe trough rim

Coat with moisture-resistant paints

Ceramic tiles onreinforced concreteservice platforms.All other floors—mosaic concretetiles

8 Pumping station –machine room

Apply concrete to walls of theunderground part using smoothformwork and float with grout. Pointseams of panel walls. Plaster brickwalls. Coat with moisture-resistantpaints to a height of 1.5 m abovefloors, balconies and erection sites,and above that, with calcimine

Sized whitewash Ceramic tiles.Concrete oninstallation floor

9 Utility and servicegalleries

Point seams of brick or panel walls.Coat with calcimine

Sized whitewash Cement

Electrical Equipment Rooms10 Transformer and

switchgear roomsPoint seams of brick or panel walls.Limewash

Limewash Cement with cementfloating

11 Completetransformersubstations, panelrooms

Plaster brick walls. Point seams ofpanel walls. Coat with light-coloredcalcimine

Sized whitewash Cement with cementfloating

12 Control station Plaster brick walls. Point seams ofpanel walls. Coat with light-coloredoil paints or moisture-resistantpaints

Coat with moisture-resistant paints

Linoleum or PVCtiles

13 Laboratories,weighing room,rooms for storageof equipment andreagents

Point seams of panel walls. Plasterbrick walls and partitions. Coat withwater-emulsion paints

Coat with oil ormoisture-resistantpaints

Linoleum or PVCtiles

14 Washing, nutrientmediumpreparation rooms

Point seams of panel walls. Plasterbrick walls and partitions. Face withglazed tiles to a height of 1.5 m, andabove that, coat with moisture-resistant paints

Coat with oil ormoisture-resistantpaints

Ceramic tiles

Note: When caustic or explosive media are present, finish work must be specified with regard for the requirementsof anticorrosion protection of structures and explosion and fire safety rules.

SNiP 2.04.02-84

164

“APPENDIX 14“Recommended

PARTICULARS OF PLANNING WATER SUPPLY SYSTEMSFOR THE WESTERN SIBERIAN OIL AND GAS COMPLEX

GENERAL INSTRUCTIONS

“1. The reservoir pressure maintenance (PPD) water supply systems of oil deposits must beclassified in water availability category I, in which case water delivery may be reduced to not more than 40percent of the design flow rate.

“2. The water intake devices of water intakes using surface sources must be prescribed per Table13 for heavy water intake conditions.

“3. The method to be used in treating river water to be pumped into beds and the composition anddesign parameters of water treatment facilities must be established depending on its quality, and therequired water flow rate and quality for specific oil deposits on the basis of preliminary proceduralinvestigations.

“4. Reagent storehouses should be designed to store a reserve allowing operation of facilities for aperiod during which conditions are unfavorable for delivery, but not longer than the guaranteed shelf life ofreagents set by the supplying plant.

“5. When underground water is used as a source of domestic and drinking water supply to oil andgas deposit construction facilities, the possibility for deferrization and accompanying removal ofmanganese and hydrogen sulfide must be foreseen directly within the water-bearing bed.

“6. Water intake pumping stations must be designed as a rule with well pumping units installed invertical tubular manholes, to which water is delivered by gravity-flow and siphon pipelines, and usingsubmersible axial and centrifugal electric pumps installed in inclined pipelines laid on the bank.

“7. Three backup units must be prescribed for category I pumping stations with more than nineoperating pumps. In this case pumps may be connected in pairs to intake and pressure manifolds withcommon gate valves.

“8. The processes of preparing and delivering water must be maximally automated.“9. When planning water supply systems, maximum use should be made of plant-manufactured

facilities and units in a set-and-block design.“10. When planning networks and facilities in permafrost, the instructions of items 15.49-15.92

should be used as a guide.

PPD WATER CONDUIT SYSTEMS

“11. Water conduits should be routed as a rule along existing and planned motor highways, and inthe shared corridors of oil and gas pipelines and other utilities.

“12. Water conduits must be laid in two or more strings.“The number of switching chambers on water conduits and the distance between switching

chambers shall be determined such that when one water conduit or a part of it is disconnected, waterdelivery can be maintained at not less than 60% of the design flow rate. A possibility for using backuppumping units should be considered in this case.

“Locating switching chambers at the places of branches from water conduits leading to deposits orclustered pumping stations when possible is recommended.

SNiP 2.04.02-84

165

“13. The length of sections of water conduits disconnected for repairs should be adopted equal tothe length of the sections between switching chambers.

“The diameters of outlets and devices for venting air must permit emptying of a water conduitsection in not more than 5 hours.

“14. Steel pipes of steel brands permitted for use in regions with an ambient air temperature ofminus 40°C or lower should be used for water conduits.

“15. The design internal pressure of water conduits must be prescribed in accordance withParagraph 8.22. Strength and stability design should be in accordance with SNiP 2.05.06-85.

“16. To protect water conduits and the equipment of supplying pumping stations working in a‘pump-in-pump’ system from pressure increases, control gates (valves), safety valves, and gate valves forautomatic water dumping must be foreseen.

“17. Installation of valves without manholes should be foreseen for welded-end valves and for airescape valves and gates for air intake and release. In this case the valve control mechanism or the entirevalve housing must be located in plant-manufactured chambers (block-boxes) on the ground surface, inwhich the temperature is maintained at not less than 5°C.

“18. Actual head losses may be adopted in computations for existing water conduits.“19. Manholes in marshy, hard-to-reach sections of a water conduit route may be made from steel.“20. Signs making it easier to find manholes should be foreseen at their locations”.