nih design requirements manual 2012 08/16/2012 committee/draft...nih design requirements manual 2012...

NIH Design Requirements Manual 2012 08/16/2012 Section 8.5

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Section 8.5 Animal Drinking Water Systems 1

2 Animal Research Facilities, Special Requirements 3 4 8.5.0. General Requirements 5

6 1. This section provides additional details addressing features unique to plumbing systems 7

serving animal research facilities (ARF). It shall be used along with other sections of the 8 DRM. The plumbing systems in the animal facility may include animal drinking water 9 systems (ADW) and waste drainage for animal research facilities. 10 11

2. Plumbing systems for ARF require close review with the animal care specialist to deter-12 mine the exact requirements and to ensure arrangements will not pose variables upon 13 animals and research. 14

15 3. Systems shall be designed in as much as possible to preclude disturbances to animals 16

during normal operation and maintenance. Systems shall be arranged to promote only 17 controlled and limited access to the animal care areas, and to the extent possible to en-18 sure that routine maintenance activities may be performed without the need to actually 19 enter the ARF, and especially the animal holding rooms. 20

21 RATIONALE 22

In addition to security and cross contamination control issues, animals can be especially sensi-23 tive to environmental elements, including vibration, noise, water/ air quality, and disruptions to 24 routine. Such disruptions can have harmful effects on animal health and research. System de-25 signs necessitating maintenance workers to enter animal rooms can pose further safety issues 26 and sanitation challenges, and can be highly disruptive to research programs. 27

28 4. System designs shall minimize potential for accumulating dirt and pest harborage. All 29

pipe penetrations, exposed equipment, mounting brackets and supports shall be caulked 30 with approved sealants. Exposed piping inside animal research facilities shall be mini-31 mized and, where required, shall standoff from walls and ceilings at least 25 mm (1 in.) 32 to permit cleaning and be constructed to minimize concealed fouling spaces and sharp 33 edges. Escutcheons shall be avoided in ARF spaces, except that durable exposed es-34 cutcheons may be used where both the piping penetrations and the final escutcheon is 35 caulked with approved sealant. The use of access doors opening into walls and ceilings 36 within the ARF shall be avoided in as much as possible, and where used shall be of an 37 approved fully gasketed type, or of an appropriate solid access housing. 38

39 RATIONALE 40

These requirements set forth basic standards for sanitary, cleanable installations within ARF, 41 and to help facilitate pest control. 42 43 8.5.1. Animal Drinking Water Systems 44 45

1. General Requirements 46 47


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a. The provision and selection of type of animal drinking water system (central bottle or 48 packet fill, piped distribution, and pre-packaged) shall be made through consultation 49 with the program. 50

51 RATIONALE 52

Each system type has technical and economic advantages and disadvantages that must be 53 considered. Bottle fill and packaged systems may be ideal for limited program areas (such as 54 barrier facilities, high containment, and areas where risk of flooding cages may be of high 55 concern); however such systems are labor intensive and offer non-continuous supply. 56 Automated systems are generally preferred for large facilities, NHP’s and large animals, and 57 can help to minimize risk of personnel injury and disruptions. 58 59

b. The required water quality and pressures shall be determined through consultation 60 with the program veterinarian and use group. 61 62

c. On-site water testing shall be performed during design to analyze the influent water 63 quality and type of treatment required. The investigation of available water supply 64 quality and determination of treatment methodologies shall consider seasonal and 65 source variations in water supply. 66

67 d. The water source and production for central-filled animal drinking water systems 68

(such as bottle and packet fill stations) are subject to the same requirements as for 69 piped distribution of animal drinking water 70

71 RATIONALE (for b and c) 72

Animal health and minimization of research variables can be dependent upon consistent, clean 73 and uncontaminated drinking water, free of contaminants, toxins, and microbes. Appropriate 74 treatment cannot be undertaken without a proper understanding of source water conditions. 75 Tolerances for variability can vary with animal models, but even where tolerances are 76 acceptable for a specific model, stability and documentation of the conditions can be critical in 77 reproducing and validating scientific results. Water supply treatment systems cannot be properly 78 designed without understanding the feed water. In some cases, feed water characteristics can 79 be subject to significant variation, including but not limited to seasonal changes, source 80 changes, and variations in upstream source water treatment. 81 82

e. The ADW production and distribution system must be completely separate from any 83 other water system and shall not serve any function other than animal drinking water. 84 System make-up shall be supplied directly from potable water systems (not lab or 85 other purified water), provided with dedicated backflow protection, and individually 86 treated with appropriate filtration, activated carbon, reverse osmosis, and additional 87 conditioning as necessary to meet program requirements. 88

89 90

RATIONALE 91 Water make-up from potable water systems is necessary to ensure the long-term stability of the 92 influent water quality and to ensure the reliability and quality is consistently appropriate and 93 uncontaminated for consumption. Laboratory water supplies (including central high purity water 94 serving laboratories) can on occasion be subject to certain degrees of contamination due to 95 backflow, equipment materials and construction, and pressure and flow variations; which while 96 well-controlled for their intended application, may not be consistently suitable for ADW. Routine 97


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maintenance and renovation shutdowns and the effects of RO membrane and system chemical 98 sanitization may pose risk to ADW. Malfunctions of controls or unintended pressure reversals 99 could result in contamination or disruption of animal drinking water. While the use of shared RO 100 production equipment (such as arrangements made up directly from potable water with 101 dedicated storage tanks, distribution, and each tank filled via an air gap, redundant controls and 102 filtered air intake) are occasionally proposed, such arrangements are discouraged because 103 even where sufficient protection at the RO source is provided initially, the protection can be 104 easily lost through an improperly adjusted control, maintenance issue, or equipment 105 modification. Further, the chemicals, cleaning, and operating procedures necessary for an 106 animal drinking water system are critical to research and animal health, and operational 107 methodologies that may be acceptable for laboratory purified systems could be detrimental to 108 animal drinking water. 109

110 f. Animal drinking water systems shall be fully engineered, as with other plumbing and 111

process systems. The A/E shall either completely design and document animal drink-112 ing water systems or (where acceptable to the project officer) provide a sufficient 113 documentation of the intended system arrangement for vendor design and A/E ap-114 proval. In such cases where full system design, sizing, and complete specifications 115 are not provided by the A/E as part of the contract documents, the A/E shall at a min-116 imum complete the required program activities to outline the system configuration as 117 acceptable to the program, provide an adequate flow diagram and schematic repre-118 sentation of the proposed system (inclusive of key production and distribution ele-119 ments, zones, and major component locations and pipe routings), provide basis of 120 design narrative and outline specifications for materials and components, coordinate 121 outline of electrical requirements, outline the design approach required for each ele-122 ment as addressed in the DRM, and shall direct conformance to the NIH DRM and 123 AAALAC documents. Such arrangements shall be followed by full system drawings, 124 calculations, and details that shall be submitted for NIH DTR and program review (in 125 addition to the A/E’s review) prior to approval and procurement. 126

127 RATIONALE 128

Animal drinking water systems have frequently been designed by manufacturers and vendors 129 as design-build arrangements rather than pre-engineered complete bid packages. Regardless 130 of who designs systems, conformance with the requirements of the DRM and design of a satis-131 factory system is mandatory and shall be demonstrated. 132 133

g. Intensity monitors shall be provided for all UV sanitizers. 134 135

8.5.2. ADW Production System Requirements 136 137

1. Contaminants (such as chemical, metal, and biological composition) shall be controlled 138 within limitations acceptable to the program veterinarian; and in no case less than 139 required for safe potable drinking water as defined by the Safe Drinking Water Act 140 (SDWA). 141

142 a. Reverse Osmosis with preliminary granular activated carbon (GAC) or activated 143

carbon block filtration is the required treatment methodology for makeup water 144 supplies, which shall originate from Safe Drinking Water Act compliant sources. The 145 A/E shall verify with the research program any need for reintroduction of ions/ 146 minerals as may be removed from the RO process or otherwise required for health of 147


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the animal species. The addition of chemical reducing agents (in lieu of activated 148 carbon) is not accepted. 149

150 RATIONALE 151

Water that is deemed potable for human consumption will typically still require additional 152 treatment to render the water consistently suitable for various animal models in the biomedical 153 research program. Maximum contaminant levels within potable water are based upon human 154 consumption and can fluctuate seasonally or as sources and treatment methods change, and 155 may not remain suitable for the needs of a research program. Sealants, fluxes, plasticizers etc. 156 that leach out in small quantities safe for human consumption in likely ingested quantities may 157 be completely unacceptable for water supplies where research must be controlled; and if not 158 controlled to an established benchmark, can vary from one location to the next. 159 160 The use of RO with appropriately sized GAC or carbon block filtration helps to maintain a safe 161 and repeatable make-up water quality with broad capability of addressing normal programmatic 162 variables, while providing protection for unanticipated water supply influent changes or quality 163 reductions (such as due to changes in treatment process, disinfectants, and emergency 164 conditions) or upstream changes in feed water supply residual disinfectant. The use of RO 165 provides significant capacity to control variation in contaminant levels and has been a proven 166 approach to meeting water quality needs. Adequately sized granular activated carbon (GAC) or 167 appropriate activated carbon block filtration provides removal of chlorine (or chloramines) that 168 may be present as residual disinfection of supply water, and is necessary to protect RO 169 membranes, in addition to protection from organic contaminants. 170 171

b. Water supply through activated carbon shall be constantly circulated through 254 nm 172 UV and post UV sub-micron filtration as necessary to control bacterial growth. The 173 activated carbon shall be provided as late in the treatment train as practical, (after 174 softeners and other multi-media beds if such components are required such as for 175 hard waters or waters with high solids) so as to maintain the presence of residual 176 disinfectant. 177

178 RATIONALE 179

Constant circulation through UV is provided to control microbial growth in activated carbon 180 between routine cartridge replacements or hot water sanitizations. Post UV filtration reduces 181 nutrient sources for microbial growth in the distribution system. It is desirable to maintain the 182 residual chlorine/chloramines disinfectants through softeners, multimedia beds etc. to help 183 control microbial growth. 184 185

c. Where buildings incorporate central water treatment or softening, the A/E shall 186 ensure that any byproducts of the upstream treatment process are appropriately 187 considered in evaluation of the available water supply and selection of treatment 188 equipment. 189

190 RATIONALE 191

Always consult with the program to ensure water quality parameters are met, and consider how 192 the actual water conditions as available at the project site may influence the available water 193 quality. 194 195


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d. All animal drinking water system qualities shall be controlled, and any significant 196 operational limitations of systems documented in the project Basis of Design. 197 198

RATIONALE 199 Occasionally unconditioned or merely filtered potable water may be requested by the program 200 (such as for non-research, housing applications), and where this occurs, the A/E shall confirm 201 that the available water quality is consistent year round and that peak contaminant levels that 202 may be achieved within the Safe Drinking Water Act are acceptable to the research program. 203 Omission of RO water treatment shall require justification and the A/E shall alert the program to 204 likely effects and limitations of proposed alternative pre-treatment method and potential 205 variables (such as any susceptibility to water treatment purveyor’s change of treatment 206 methods, water source, or residual disinfectants). The application of pre-treatment filters and 207 carbon filters to remove particulate and residual disinfectants with no further treatment may 208 leave the system prone to excessive microbial and biofilm contamination, and omission of 209 reverse osmosis or suitable ultrafiltration (UF) may leave the system susceptible to a variety of 210 contaminants and quality fluctuations. 211 212

2. Usable total storage tank volume shall be sized in accordance with program 213 requirements and to provide for not less than 48 hours peak system demand. The use 214 of duplex tanks in parallel is strongly recommended. System operating sequence shall 215 ensure each tank achieves frequent turnover. 216

217 RATIONALE 218

Reserve capacity in storage tanks is necessary to ensure availability of water supply during 219 maintenance or in the event of system malfunction. However, frequent water turn-over is 220 desired (ideally once per day), and over sizing of tanks can result in microbial contamination. 221 Turnover of tanks and use of larger tanks can be achieved through diligent maintenance, 222 including frequent (possibly monthly) system sanitization, circulation of tanks and use of UV. 223 Large systems can benefit from parallel arrangements of multiple tanks in series to achieve 224 turnover and redundancy. 225 226

3. Isolation valves shall be provided for each component such that system will not have to 227 be shut-down or run in emergency bypass mode for routine maintenance. 228

229 4. The entire system shall be designed to provide continuous ADW to the ARF (or fill 230

station), and critical functions shall be automatically monitored to the central ARF 231 monitoring system or BAS (as determined by each program), with remote telemetry. 232 Systems shall be designed to preclude single-point failures. 233

234 5. Provisions shall be incorporated to ensure that even with failure of primary equipment 235

and incoming building potable water (such as due to maintenance, pipe breakage etc.) 236 suitable drinking water supply to animals will not be compromised. Redundant water 237 conditioning equipment shall be provided as determined appropriate by the user group in 238 consideration of facility operating procedures and available system maintenance. Refer 239 to Section 8.1 Plumbing Design, (Link) and Section 8.3 Water Systems (Link). 240

241 6. Automatically monitored functions shall include at a minimum the following: 242 243

a. Make-up Water Supply Flow/ Pressure 244 245


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b. RO System Operation 246 247

c. ADW Storage Tank Level 248 249

d. Loop Flow Meter (for circulating systems) 250 251

e. ORP/pH/ Dissolved Ozone/ UV (as appropriate and applicable) 252 253

f. Proportioner Chemical Level Monitoring 254 255

g. Pressure and Flow Monitoring of Individual PRV/Flush Stations 256 257

h. Distribution System Water Temperature 258 259

7. The system shall be provided with sampling points from which product water may be 260 readily taken to verify water quality and proper treatment component operation. At a 261 minimum, such sampling points shall be at the beginning and end of distribution, remote 262 from the flush valve. 263

264 RATIONALE (6 and 7) 265

The program will need to evaluate SOP’s, maintenance, and disaster response plans to ensure 266 supplies will be continuously available in the event of unforeseen circumstances (work 267 stoppage, disaster, pipe breakage etc.) The results of these considerations can impact the type 268 of ADW system selected. Required provisions to ensure continuously available water include 269 adequately sized and/or multiple storage tanks, redundant continuously operating distribution 270 equipment (such as circulation or pressurization pumps); and dual-fed or emergency water 271 supply connections for potable water sources serving the ADW system, and an emergency 272 bypass mode for potable water in the event of catastrophic failure. In some cases, dual 273 production equipment may be warranted. Automatic monitoring is required to provide the most 274 immediate alert for system malfunction. Manual sampling ports are required for required 275 periodic water quality sampling. 276 277 8.5.3. ADW System Microbial Control 278

279 1. Provisions to ensure control of microorganisms and biofilms shall be addressed in the 280

design of ADW systems. 281 282 2. Each animal drinking water system shall be provided with a proportioner and automated 283

injection system to facilitate normal water treatment and periodic sanitization, except 284 where non-chemical microbial control is utilized. The proportioner shall inject chemicals 285 into a monitored buffer tank, and include a fail-safe arrangement to preclude over 286 dosage. In most cases, animal drinking water is acidified (typically with USP grade 287 sulfuric or hydrochloric acid) to a pH of 2.5 to 3.0 or provided with residual chlorination 288 (only with water pH above 5.0), typically at 0.5 to 1.0 mg/L free chlorine at the remote 289 end of the system (starting with 2-3 mg/L total chlorine at the source). Maximum 290 system disinfectant levels shall be determined by the program veterinarian, but generally 291 chlorine levels above 2 to 3 mg/l are undesirable as they can be excessively corrosive to 292 piping, emit strong odors, and may affect palatability in some species. In some cases, 293 routine operation at levels above 10 mg/l may be required and acceptable for some 294


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species. Chlorination shall not be used in conjunction with acidic waters due to potential 295 release of chlorine gas and byproducts. 296

297 3. Where neither acidification nor residual chlorination is acceptable to the program, 298

alternative methods of systems microbial control may be utilized with program and DTR 299 approval. For example, while application of 254 nm UV in itself is generally not sufficient 300 for microbial control due to lack of residual disinfection properties, if system velocities 301 are maintained, clean-joint piping systems are utilized, and sufficiently frequent 302 sanitization procedure is followed using ozone or hyperchlorination, such chemical-free 303 operation is acceptable. 304

305 a. UV sanitizers shall be sized for at least double the peak system flow, 306

provided with UV intensity monitors, and submicron (ultrafiltration) shall be 307 provided downstream of UV to reduce dead organic matter as a nutrient 308 source that may promote re-establishment of biofilms. 309

310 4. Continuous recirculation shall be provided through the activated carbon bed with UV 311

254nm, and submicron filtration should be provided. Potable hot water (60-80 degrees 312 C) sanitization or (more commonly) replacement of activated carbon cartridges should 313 occur frequently as determined necessary for microbial control. Small activated carbon 314 block filter cartridges should be frequently replaced where routine activated carbon bed 315 sanitization features are not practical. 316 317

5. System designs should minimize deadlegs; however, the use of zero-static components 318 is not required. Branches to cage racks, rooms, and other lines that are routinely used 319 and flushed to achieve water turnover are not considered deadlegs. 320

321 RATIONALE 322

These provisions are required to control microbial contamination and biofilms, which can be 323 especially problematic where water systems are not maintained with chlorination or acidification. 324 325

6. Regardless of routine water treatment, systems must be sanitized periodically and shall 326 be designed to accommodate routine sanitization. The desired method of routine 327 sanitization shall be determined through consultation with the program. System design 328 and materials shall be compatible with the following methods, as selected through 329 consultation with the program: 330

331 a. Routine sanitization can be accomplished by disconnecting all racks and flushing 332

with chlorine at 30-50 mg/L concentration (typically for 30 minutes to 2-hours), 333 followed by complete flushing and manual sampling. 334 335

b. Sanitization can be accomplished with systems that are furnished with 254nm UV 336 light and an ozone generator by turning off the UV light, flushing with ozone 337 (typically at 0.4 mg/L for 10 minutes) as measured by a dissolved ozone monitor, 338 and then destructing ozone through activation of the 254nm UV light. System 339 ORP can be measured at RO system to achieve base readings, and again in the 340 loop to determine likely sufficient disinfection. In some cases, ORP 341 concentrations up to 2.0 mg/L may be required. Ozone destruct shall be verified 342 (dissolved ozone monitor and flushing can be utilized) prior to restoring water 343 use. 344

345


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c. Additional acceptable means of system cleaning may include heat sanitization 346 (typically at temperatures of at least 70 to 82 degrees C) provided system design 347 and components are suitable for elevated temperature. 348

349 RATIONALE 350

These provisions, in conjunction with appropriate pre-treatment and distribution system design 351 provide guidance to achieve systems designs which promote microbial control for animal 352 drinking water. Frequency of required system sanitization will vary for each program as 353 determined by the user group, water quality, and system selection. Typically such sanitization 354 will occur on either a biweekly, monthly, or quarterly basis, depending on program requirements 355 and system design. The approach to sanitization must be considered up front and understood 356 by system designers such that appropriate provisions can be made for effective and efficient 357 application. In starting up systems or while systems are non-operational for extended periods, 358 the system should be acidified, chlorinated, or run with ozone at proper levels to preclude 359 biofilms proliferation. 360 361

7. Where piped ADW systems are provided, a disinfectant flush station shall be provided in 362 the cagewash areas such that individual manifolds and hoses may be routinely 363 disinfected by flushing with chlorinated or ozonated water. 364

365 RATIONALE 366

Rack manifolds must be sanitized periodically to control microbes and potential for cross 367 infection. 368

369 8. Disinfection byproduct (DBP) levels shall be controlled in accordance with the 370

requirements of the program as deemed appropriate for the animals served and in 371 consideration of initial water quality and selected microbial control methods. Maximum 372 levels of disinfection byproducts must be established in concert with the program. 373

374 RATIONALE 375

High levels of disinfection byproducts (such as but not limited to bromate and trihalomethanes) 376 can occur with certain microbial control methods and can be influenced by on-site water 377 conditions. For example, high bromate levels can result from water supplies disinfected with 378 ozone where initial bromide levels are elevated. Excessive trihaomethanes and haloaetic acid 379 levels can occur from reactions with chlorine. The US EPA Safe Drinking Water act provides 380 guidance as to maximum acceptable levels of DBP’s for potable water systems which may be 381 utilized as a baseline, however the SDWA permissible values of certain DPB’s will likely be 382 exceeded where high levels of disinfectants (such as hyperchlorinated drinking water) is elected 383 by the program. The topic of acceptable DPB’s levels should be discussed and may influence 384 ADW design and treatment approaches. 385 386 8.5.4. Distribution System, General Requirements 387 388

1. System pressure shall be controlled by high quality automatic pressure regulating 389 valves, suitable for the pressure range and turn-down ratio required, and fitted with 390 means to monitor pressure setting. 391 392

2. Where a production system serves more than one floor, building, or building wing, each 393 floor or other major area shall be separately zoned with individual horizontal supply 394


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main(s) provided for each floor and building area. Refer to Pressurized Systems 395 Distribution in the Plumbing Design, Section 8.1. (Link) 396

397 3. Distribution systems shall be arranged to ensure either continuous circulating flow of the 398

supply loop and returns with supplemental flushing of individual rack manifolds, or to 399 provide complete automated flushing of the entire system including individual rack 400 manifolds. 401

402 4. After the supply drop to individual rack manifolds, the manifold shall flush to a room or 403

individual manifold flush connection such that there is no distribution of water past 404 drinking water nozzles from one rack manifold to the supply of the next manifold or 405 room. 406

407 5. Systems shall be arranged to permit fresh water system turnover and to limit dead-legs, 408

and system flush volume/ duration shall turn over piping contents at least once daily. 409 410 6. Distribution equipment (such as pumps) required to maintain system flow shall be 411

redundant, and alternating or otherwise maintained in constant low flow operation. 412 System pressures within each zone shall be appropriate for each species, and flushing 413 pressures shall not pose hazards to animals. 414

415 7. Systems may be automatic flushing or circulated type with supplemental flushing, as 416

follows: 417 418

a. Automatic Flushing Distribution Systems: Central production systems shall distribute 419 ADW through a horizontal serpentine distribution arrangement to each holding room, 420 or through a horizontal central supply main with an individual branch to each holding 421 room. Automatic flushing systems shall comply with the following: 422 423 i. Multiple zones shall be provided as required by the program or as appropriate for 424

varying species. 425 426

ii. The distribution main within each room shall individually connect to each rack 427 manifold, and the ends of each manifold shall automatically flush through a 428 plumbing-code compliant air-gap to a sink, drain trough, or individually connect to 429 a collector manifold discharging through an air gap to an approved location. 430

431 iii. Reverse “S” type manifolds (with supply from the bottom) are preferable to afford 432

complete flushing and removal of air. 433 434

iv. Dedicated PRV stations are required for each room to permit program flexibility, 435 except that a single PRV station may serve up to six rooms of the same type 436 within the same program where approved by the user group. 437

438 v. System shall be sized to achieve flow velocities during flushing cycles between 3 439

and 6 FPS for PVDF and Low extractable PVC piping and between 3 and 8 FPS 440 for stainless steel. 441

442 b. Circulating Distribution Systems: Central production systems shall distribute ADW 443

either through a horizontal serpentine distribution mains arrangement from one 444 holding room to the next, or through a flow-verified and properly balanced horizontal 445


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supply and parallel-return piping mains system (such as a horizontal direct return or 446 reverse return mains arrangement, whereas a single supply feed is provided to each 447 room with return back to single or multiple return mains). Each return branch shall be 448 fitted with a flow meter and balancing device to verify proper flow, and with the 449 exception of serpentine systems or systems with individual room flush, a single 450 supply and return connection shall be provided for each room. Circulated distribution 451 systems shall comply with the following: 452

453 i. Circulating systems shall be arranged so as to achieve complete circulation of 454

supply mains and through all returns. 455 456

ii. Drops to individual rack manifolds shall not circulate. Drops to racks shall 457 connect to an “S” type rack manifold, and the end of each rack manifold shall 458 automatically flush with a plumbing-code compliant air-gap to a sink, drain 459 trough, or collector manifold discharging through an air gap to an approved 460 location. 461

462 iii. Pumps shall be sized and calculations demonstrate that sufficient supply to 463

demand ratio and flow rate is provided that under all demand conditions and 464 variations of total connected rack load, normal velocities corresponding to an Re 465 not less than 10,000 is achieved for all piping systems, except that the minimum 466 velocities in stainless systems should be at least 2 FPS. Sanitation velocities 467 shall be between 3 and 6 FPS for Plastic piping and between 3 and 8 FPS for 468 stainless steel piping. 469

470 iv. Dedicated PRV stations are required for each room to permit program flexibility, 471

except that a single PRV station may serve up to 6 rooms of the same type within 472 the same program where approved by the user group. 473

474 v. Forced circulation shall not occur through PRV stations. 475

476 vi. Small facilities permanently intended to house only a single species may be 477

served by a single PRV station with approval of the program and NIH DTR. 478 479

vii. The maximum temperature of circulating systems shall be controlled (typically 480 with automatic flushing) and monitored. 481

482 RATIONALE 483

These provisions outline acceptable ADW arrangements to achieve satisfactory system 484 operation, maximal programmatic flexibility, minimize cross infection, and to help control and 485 sanitize systems of biofilm. Redundancy of distribution equipment is necessary to maintain 486 system flow in the event of malfunction or maintenance. Maintaining pumps in a frequently 487 alternating basis (such as every 12 hours) or in a low flow condition (such as 50% capacity) can 488 minimize stagnation, and pumps can be ramped up in parallel to achieve higher velocities for 489 system sanitization. Indicated minimum velocities help maintain passive layer corrosion 490 protection in stainless steel and assist with control of biofilm. The use of elevated velocities 491 beyond these criteria is unnecessary and may result in premature erosion, heat gain, and 492 energy consumption. Excessive velocities are of little benefit as required forces to adequately 493 shear biofilm would be significantly higher than may be obtained from pipe flow (and laminar 494 flow regions will nonetheless remain along the pipe wall). Limitations on numbers of rooms per 495


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PRV station are provided to ensure programmatic flexibility, and due to limitations of achieving 496 appropriate system pressure control and circulation as associated with the use of pressure 497 reducing valves. Excessive uncirculated piping downstream of PRV stations relies upon system 498 flushing to achieve water turnover. 499 500

8. System controls or valving should permit flushing controls valves to be individually 501 activated or disabled. Each zone shall be provided with valving to facilitate independent 502 isolation. 503

504 RATIONALE 505

Valving may be required to facilitate system repair without necessitating total system shut-down. 506 507

9. The arrangement of system zoning, need for cross contamination control provisions, 508 provisions to accommodate varying species and their unique water quality and pressure 509 requirements for each room or zone shall be evaluated and appropriate provisions 510 provided as approved by the user group. System zoning shall allow for independent 511 isolation of sections of the system to manageable program areas, without affecting 512 zones on other floors, building wings, or other program areas or species. 513

514 RATIONALE 515

As demand for animal space changes and system maintenance is required, the design shall 516 facilitate flexible and adaptable operations without affecting or compromising services to other 517 program areas or animal species. 518 519

10. Horizontal piping should be mounted at least 300 mm above rack height or otherwise be 520 protected to minimize potential for damage. Piping must be located to minimize potential 521 for damage from animals or mechanical impact. The use of plastic mounting clips for pip-522 ing shall be avoided. 523

524 RATIONALE 525

The use of plastic mounting clips may be subject to premature breakage from rack movements, 526 impact, cleaning and wear. 527 528

11. The A/E shall coordinate with the program to address flood risks. 529 530

RATIONALE 531 Rack flooding can cause significant loss of research, either due to animal drowning or thermal 532 effects. A number of planning steps can minimize potential of flooding cages and should be 533 discussed during system design. Cages may be fitted with screened drain openings and piped 534 gutter systems, specific nozzle types may be selected to minimize flood risk, and automatic 535 systems may be omitted in certain areas as part of flood control for areas deemed of special 536 concern. 537 538

12. The A/E shall ensure that Animal Drinking Water operating, control, and monitoring sys-539 tems are appropriately served with building stand-by power. 540

541 13. All systems shall be tested at 150% design operating pressure for not less than 8 hours, 542

or at the maximum working pressure ratings of the system. Minimum test pressure shall 543 not be less than 100 PSIG unless justified and approved by the project officer. 544

545


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14. Completed animal drinking water systems shall be flushed, commissioned, and sanitized 546 prior to turn over for occupancy. Necessary precautions shall be taken in the start-up, 547 testing, and commission phase to preclude proliferation of biofilms. Integrated systems 548 testing of system response to power failure shall be confirmed. 549 550

RATIONALE 551 Required to ensure proper operation for occupancy 552 553 8.5.5. ADW System Materials 554

555 1. System materials (including elastomers used in controls, solenoid valves, seals and Lixit 556

nozzles) shall be durable for system water quality, chemical treatment, and routine 557 sanitization methods. 558 559

2. For NIH facilities, the preferred distribution material (where deemed compatible with 560 water quality and microbial control and disinfection methods) is the use of 316 stainless 561 steel. 562

563 RATIONALE 564

Where compatible, stainless steel piping is preferred due to its inherent mechanical strength 565 (resistance to breakage) and cleanability. However, stainless steel may not always be 566 appropriate for long-term corrosion resistance (such as in high chlorine concentrations). 567 568

3. System materials shall comply with the following: 569 570

a. Approved piping materials are electropolished type 316L stainless steel tubing with 571 either sanitary joints or orbital weld and post-weld passivation. 572

573 b. PVDF (polyvinylidiene fluoride) with butt fusion or socket fusion joints and general 574

use of Viton elastomers. Electrofusion joints (embedded coil) are not acceptable. 575 576

c. Where system utilizes high concentrations of chlorine or acid, the use of PVDF may 577 be required. The A/E shall confirm compatibility of fluids with system materials. 578

579 d. System piping joints shall be sanitary type, smooth and free of fouling spaces. 580

581 e. The use of low extractable PVC with low extractable PVC cement joints constructed 582

to ultra-pure water standards may be accepted for some applications, subject to 583 approval of the program and provided sufficient attention is made to joint quality to 584 minimize dead spaces and over-application of cement in the water way. Where 585 PVC is utilized, sufficient cure (generally 24 hours) shall be provided before flushing 586 to minimize leach out of TOC’s. 587

588 f. Elastomers: EPR, Nitrile, and butyl rubber shall not be utilized for any systems where 589

ozonation will be utilized. Natural rubber shall not be utilized. Viton is generally 590 suitable for most applications. 591

592 g. Recommended filter media for all systems is generally PVDF or PTFE. 593

594 h. All system materials (piping, tanks, etc.) shall be opaque and sufficiently inert to 595

preclude unacceptable leaching of contaminants. 596


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597 i. Pumps shall be appropriate stainless steel or PVDF-lined, non-fluid contaminating 598

centrifugal type. 599 600

j. Tanks may be natural polypropylene/polyethylene, or natural PE/PP or PVDF lined 601 fiberglass, except that PE/PP is not approved for applications with ozone. 602

603 k. Light traps and UV intensity monitors shall be provided at all UV sanitizers. 604

605 l. Where translucent materials are utilized or materials are susceptible to UV 606

degradation (such as low extractable PVC piping) shielding (such as closed cell 607 foam, opaque plastic sleeving, or vapor barrier jacketing) shall be provided. 608

609 RATIONALE 610

Materials must maintain long-term durability, chemical resistance, and not contaminate system 611 water quality. Opaque materials are utilized to reduce potential for growth of algae. Specific 612 limitations are required for materials exposed to chlorine, acidification, UV light, and ozone. 613 Natural rubber shall not be used in ADW systems as these serve as a nutrient for bacteria. 614 PVDF and PTFE filter media provide resistance to the range of disinfectant and sanitization 615 methods utilized, including ozonation. 616 617

4. Specifications shall mandate quality control provisions (such as recent manufacturer 618 training and certification for fusion equipment and low-extractable solvent cement pipe 619 joints), as well as inspection protocol and non-destructive test procedures to ensure 620 quality control. Certification of training for each installer shall be provided in project 621 submittals. 622

623 RATIONALE 624

Proper materials handling, storage, and installation techniques help to ensure an uncontaminat-625 ed system. Numerous leaks have occurred in piping systems due to improper or partial joint 626 fusion (often caused by poor technique or improperly calibrated equipment). Poor solvent ce-627 ment technique can result in premature failure and/or compromised water quality. Inspection 628 protocols for review of fusion joints, including installer qualification records review, calibration, 629 reports, and NDT methods of visual inspection (such as black light flash light inspection of low 630 extractable PVC joints should be applied. 631

632 5. Where low-extractable PVC systems are utilized, specifications shall require that each 633

installer be certified by a manufacturer approved instructor for proper performance of the 634 solve weld joint for the range of pipe sizes applicable to the project. Such fusion joints 635 shall be made only with manufacturer approved low-extractable PVC cement, and 636 certification of training for each installer shall be provided in project submittals. System 637 joints shall be specified to be cured fully and for not less than 24 hours, prior to fill with 638 water. Low extractable PVC piping shall be protected from exposure to UV light 639 including interior florescent lighting with approved shielding materials (such as 640 compatible closed cell foam pipe insulation, opaque plastic sleeving or vapor barrier 641 jacket). 642

643 8.5.6. Water Distribution Systems for Animal Research Facilities 644

645 1. Requirements 646

647


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a. Water systems serving ARF shall comply with requirements for laboratory and do-648 mestic potable water systems. The following requirements are especially applicable 649 to animal research facilities. 650

651 i. ARF holding rooms, cagewash, and similar areas may be supplied from common 652

laboratory water systems serving areas of equivalent biosafety level, except that 653 extension from the potable water system shall be provided to all areas and func-654 tions for which potable water quality is required. 655 656

ii. Water supplies to Animal Research Facilities must be reliable, with provisions to 657 preclude single point failure (including redundancy) and arranged to ensure con-658 tinuous operation. 659

660 iii. Water supplies to animal food preparation areas, make up to animal drinking wa-661

ter systems, surgical scrub, surgical sterilization, transgenic/ barrier facility steri-662 lizers or and other areas where the water supply may be directly ingested shall 663 be made up directly from the potable water system (with backflow protection as 664 required by code) and treated to the degree required for the application. Refer to 665 Exhibit X8.3.A Water Distribution (Link) 666

667 iv. Water supplies for cagewash, tunnel wash, sterilizers and similar equipment 668

must typically be softened for control of scale. The use of duplex (in parallel) ion-669 exchange softeners with potassium chloride demand controlled regeneration or 670 membrane softeners is advocated. Dedicated water heaters arranged to provide 671 N+1 redundancy shall be utilized to serve central cagewash areas. Building-wide 672 production and distribution of soft water or high temperature water is normally not 673 required or cost-effective and is typically unnecessary for projects at the NIH 674 campus in Bethesda, MD. Refer to Exhibit X8-3-D Maximum Hot Water Outlet 675 Temperature (Link) 676

677 v. Refer to Section 8.3 Water Systems for additional requirements for all water sys-678

tems, including backflow protection, temperature, and general design criteria ap-679 plicable to ARF areas. 680

681 vi. The routing of piping in ceilings above animal areas shall be avoided in as much 682

as possible. 683 684

b. Plumbing Fixtures and Equipment for Animal Areas: Refer to Plumbing Fixtures 685 Section 8.2 (Link)for requirements for drains, troughs, hand sinks, faucets, and other 686 plumbing fixtures and equipment serving the Animal Research Facility. 687

688 8.5.7. Waste Systems from Animal Areas 689


692 a. ARF waste systems shall comply with the general waste system requirements in 693

Section 8.6 Drainage Systems. (Link) Waste with high solids (such as from large an-694 imal holding rooms, jetted drains and trough drains) shall discharge to the sanitary 695 system (or ideally to the sanitary sewer manhole) independent of other building are-696 as through corrosion resistant piping, and shall bypass pH treatment systems unless 697 pH treatment is specifically necessary based on program requirements, and provided 698


Page | 15

the pH treatment system is provided with operational redundancy and arranged to 699 accommodate large quantities of solids. Refer to pH treatment section of Section 8.6 700 Drainage Systems (Link) for related requirements that may influence system configu-701 ration. 702 703

b. Animal research facility waste shall be separated from general sanitary and lab 704 waste systems in as much as possible. 705

706 c. Final system tests (after traps are set) to confirm system tightness and ensure no 707

leakage of sewer gas is critical in Animal Research Facilities. 708 709

d. Minimum slope of waste piping serving animal areas is 2% for pipe sizes 6-inches 710 and smaller. Slopes of up 3 to 4% are recommended. Horizontal piping shall be ar-711 ranged to minimize horizontal to horizontal offsets and to maximize efficient transport 712 of solids. 713

714 RATIONALE 715

Waste stream from animal areas are especially subject to stoppage due to high solids loads. 716 Discharge of waste from other building areas into the ARF can cause flooding within the ARF in 717 the event of waste line/ sewer stoppage. It is much preferred that wastes from main building 718 areas (especially upper building levels) bypass the ARF. In all cases, conformance with back-719 water requirements as indicated in Section 8.6 Drainage Systems (link required) is required to 720 minimize risk of flooding. pH treatment is not normally required for ARF wastes, however the 721 use of corrosion resistant piping is mandatory to accommodate extensive use of cleaning prod-722 ucts and animal wastes. Where pH treatment systems are provided, they must be especially 723 designed for receipt of sewage. Sewer gas and ammonia smells are common in ARF facilities 724 where plumbing systems have not been adequately designed or installation deficiencies are not 725 detected prior to occupancy, and detection and repair of such odors can be highly disruptive to 726 facility operations and in some cases disrupt required environmental characteristics. 727 728

e. Cagewash area discharge shall route through the lab waste system pH neutraliza-729 tion, with careful attention in the design to ensure adequate waste sizing, slope, and 730 materials selection to accommodate surge flows, suds, and high temperature dis-731 charge. All drains within cagewash areas shall discharge through pH neutralization, 732 except that bedding disposal units shall discharge through the sanitary system and 733 steam sterilizers may discharge through the sanitary or lab waste system. 734 735

f. The A/E shall consider the likely solid load (such as bedding, paper, feces, slurry) in 736 each portion of the piping system and design systems for efficient transport of waste 737 and to minimize stoppages. Where bedding disposal units are provided, they shall be 738 hard piped with a cleanout on the trap inlet, fitted with not less than a 100mm (4-739 inch) diameter trap, and the receiving main should receive waste from at least one 740 steam sterilizer or similar fixture with high flow rate. A minimum slope of 2%, and 741 ideally 3 to 4% shall be provided for such piping, and discharge of sufficient suitable 742 trail flows (such as from large steam sterilizers) into the main line serving such drains 743 should be provided to ensure transport of solids. 744

745 RATIONALE 746

Extensive use of chemicals (including sanitizers, cleaning and descaling agents) are utilized in 747 cagewash area, and in addition pH treatment systems on cagewash equipment may not be 748 consistently reliable, adequately maintained, or consistently calibrated to accommodate the 749


Page | 16

range of pH variations and required treatment process and duration to preclude effluent dis-750 charge contraventions. Sufficient waste slope, trail flows, and hydraulic depth is necessary to 751 ensure adequate drainage velocity to carry high solid waste streams. Surge loads from cage 752 wash, tunnel wash, sterilizers and similar equipment can be substantial as such equipment may 753 often be in simultaneous operation. Tunnel washers, pre-rinse areas, and similar equipment 754 may discharge excessive solids that must be accommodated without plugging the waste sys-755 tem. 756 757

g. The routing of piping above animal holding areas shall be avoided in as much as 758 possible. Waste piping shall not be routed above surgical areas. 759

760 RATIONALE 761

Avoiding disruptions related to maintenance, potential leakage, and piping systems are im-762 portant factors in animal facilities. Waste piping above aseptic surgical areas can compromise 763 required sanitary conditions. The use of fixtures which discharge waste above the floor, as well 764 as the use of BAS-monitored double-contained waste piping shall be provided where such pip-765 ing cannot be avoided over surgical areas. Drain pains (with or without drains), heavy duty 766 joints and similar provisions are not considered equivalent to the safety of a monitored leak-tight 767 double contained waste system over critical areas, however efforts shall first be made to avoid 768 piping above such spaces. 769 770

h. Discharge of water above 60 Degrees C (140 Degrees F) prohibited. Cagewashers, 771 Tunnel washers, Sterilizers, and similar equipment shall incorporate suitable after-772 coolers to ensure discharge waste temperature does not exceed 60-degrees C (140 773 degrees F). Cooling systems shall incorporate a means to limit water waste, and 774 where feasible closed-loop cooling should be provided. Where once-through water 775 must be utilized, the use of suitable water sources (such as RO reject water) should 776 be considered. Refer to Section 8.6 Drainage Systems (Link) for additional require-777 ments relative to potential high-temperature waste discharge. 778

779 RATIONALE 780

High temperature water discharge can damage plumbing equipment and components and vio-781 lates discharge regulations. 782 783

i. Where necropsy table drains are connected to the building waste system, a 3-way 784 full flow valve at the trap inlet shall be provided to permit waste collection into a local 785 carboy for proper disposal, or diversion to the lab waste system, as appropriate. 786

787 788

RATIONALE 789 Effluent may require capture for biological waste disposal. 790 791

j. The A/E shall review the need for floor drains with animal facility personnel. Floor 792 Drains shall be provided in animal rooms only where required by the program and 793 the AAALAC Guide. 794

795 RATIONALE 796

Floor drains are not typically required or desired in small animal rooms, particularly those hous-797 ing rodents. Floors in such rooms can be maintained by wet vacuuming or mopping with appro-798 priate disinfectant cleaners. Unnecessary floor drains can provide a breeding ground for in-799 sects, introduce sewer gas/ odors, and additional maintenance concerns. For some animal 800


Page | 17

rooms however, (such as NHP open cage housing), drains are necessary to facilitate appropri-801 ate sanitation. 802 803

k. Where floor drains are used in Animal Research Facilities, conform to the following: 804 805

i. Floor drains, trench/trough drains, and flushing/jetted drains shall conform to re-806 quirements under Section 8.2 Plumbing Fixtures. (Link) 807 808

ii. Sufficient means shall be provided for clearing waste stoppages without disrupt-809 ing animals, including (where possible) placement of cleanouts outside animal 810 holding rooms and to serve mains. Two-way cleanouts located outside the hold-811 ing room (including on trap arms) should be utilized to serve NHP rooms where 812 feasible. 813

814 iii. Where floor drains are provided in small animal areas, drains shall be fitted with 815

automatic electronic time-clock operated trap seal primers. 816 817

iv. Deep seal traps and running traps shall not be used unless specifically required 818 by the proposed application. 819

820 v. Sufficient drainage shall be provided to ensure the rapid removal of water and 821

drying of surfaces. The minimum pitch of trench/trough drains is 2%. 822 823 2. Floor Drains in Large Animal Spaces 824

825 a. Floor drains in large animal spaces (NHP’s, kennels, etc.) shall conform to the follow-826

ing additional requirements: 827 828

i. For typical holding rooms, a single jetted drain shall be located in the common 829 end-wall trough (where side wall troughs collect into this common trough, or sep-830 arate drains may be provided for each trough. Each trough shall be provided 831 with a trough rinse. 832 833

ii. Collector mains serving holding rooms shall be a minimum of 100mm diameter 834 with not less than 2% slope. Drainage mains in large animal holding rooms may 835 require 150mm diameter piping depending on configuration and load. 836

837 RATIONALE 838

These provisions are to ensure rapid evacuation of water from animal holding rooms, maintain 839 sanitation, minimize potential for waste line stoppages and sewage back-ups in the ARF, and 840 reduce potential for sewer gas infiltration. 841 842 8.5.8. Remote Bedding Disposal Systems 843


846 a. The selection of bedding disposal arrangements shall be evaluated with the user 847

group and must carefully consider whether bedding will always be dry or might be-848 come wet or slurry. 849 850


Page | 18

b. Redundant drive sources (vacuum pumps, motors etc.) shall be provided to ensure 851 continuous operation and facilitate routine maintenance without disrupting ARF op-852 erations. 853

854 c. Piping radii for directional changes must be appropriate and arranged to minimize 855

potential for stoppages. Direct routing with minimal horizontal to horizontal offsets 856 shall be provided and documented in design drawings. 857

858 d. Overhead piping systems shall be arranged to facilitate disassembly for clearing of 859

stoppages, or provided with appropriate cleanouts. The provision of well-designed 860 cleanouts is preferable and must be detailed on drawings. Such cleanouts must be 861 arranged to seal tight, and shall be specifically detailed so as not impede flow or ul-862 timately contribute to stoppages. 863

864 e. Piping transport systems shall be arranged to provide appropriate vibration/sound 865

isolation. Routing must be shown on drawings and properly coordinated so as to 866 avoid post-design conditions that result in excessive offsets and stoppages, and to 867 ensure that equipment is appropriately sized for actual static pressure requirements. 868

869 f. System routings should (where possible) avoid animal holding rooms and other 870

spaces where associated noise and maintenance access may be an issue. 871 872

g. Arrangement of system exhaust shall be coordinated with HVAC requirements to 873 preclude odor infiltration. 874

875 h. Where bedding disposal discharges to plumbing systems (such as with grinder and 876

pulverizing units), conform to ARF waste system plumbing requirements indicated 877 above to minimize potential for waste stoppages. Waste from bedding disposal units 878 shall be direct (hard pipe) connected. The use of reclaimed water (such as from 879 cage wash final rinse) should be considered for minimization of water waste. The 880 A/E shall consider provision of a jetted trap to serve the disposal unit where neces-881 sary to minimize potential waste stoppages. Traps serving bedding disposal units 882 shall be at least 4-inch diameter. The use of 6-inch trap and use of piping at slopes 883 of 3-to 4% may be adequate, especially where sufficient water flow for drain line 884 transport is provided. 885

886 i. User training shall be included as a requirement in design documents to ensure us-887

ers are familiar with the proper operation and limitations of the selected system. 888 889

RATIONALE 890 Malfunction of bedding systems can be highly disruptive to cagewash operations. Frequent dis-891 assembly of piping systems to clear stoppages is undesirable, and even where remote systems 892 are designed for handling of only dry bedding, moisture often enters systems and contributes to 893 clogs. Cleanouts that are out of the flow path and pose no flow restriction (such as cleanouts 894 that extend as floor cleanout access housings to suitable service areas on the floor above) 895 should be provided, but must be arranged to consistently ensure a gas-tight seal to preclude 896 ammonia odors. The use of pressure-system compatible threaded caps or gasketed flanges 897 within access housings are examples of effective approaches, standard drainage system 898 cleanout plugs may be susceptible to leakage). Removable spool pieces and flanged elbows 899 can also be used to facilitate cleanout access in some cases; however maintenance for such 900 arrangements can be highly disruptive if such are within program areas. Systems must be ap-901


Page | 19

propriately engineered and located to preclude disruption to animals and faculty operations re-902 sultant of noise, malfunction, and service requirements. Systems shall not be left as a vendor-903 designed without sufficiently defined criteria and established routings and salient features in de-904 sign documents. 905 906 8.5.9. Alkaline Hydrolysis Tissue Digestion 907

908 1. Regulator/community acceptance of wastewater from alkaline hydrolysis can impact the 909

viability of equipment use, the type of system selected, and the extent of waste water 910 treatment (if any).Such systems typically produce extremely high effluent BOD, COD, 911 TSS, TDS, and nitrogen wastes which may substantially exceed permitted discharge 912 regulations. It is imperative that the A/E coordinate with the program through the NIH 913 project officer to obtain approvals from the serving sanitary sewer authority prior to se-914 lecting and implementing alkaline hydrolysis tissue digestion. Due to the biological and 915 technical complexities and sensitivities associated with tissue digesters, all communica-916 tion and coordination with local municipal water and waste authorities dealing with efflu-917 ent discharge shall originate with the Institutional Biosafety Office with support from the 918 Project Officer and the A/E. An emergency shower and emergency eyewash shall be 919 located in the tissue digester room, in close proximity to the tissue digester, and any ar-920 ea where chemicals are handled. A hand wash sink shall be provided in the room serv-921 ing the tissue digester. Unprotected potable water shall not be extended into the car-922 cass disposal room. 923

924 RATIONALE 925

Water supplies to spaces handling carcasses must be protected from backflow and shall not be 926 subject to unprotected cross connections. 927 928

2. Water supply to tissue digesters shall be from the laboratory cold water system. An 929 ASSE 1013 backflow preventer shall be provided at the water connection to the equip-930 ment to isolate the tissue digester from the laboratory water system. 931

932 RATIONALE 933

ASSE 1013 backflow protection provides the minimum acceptable level of backflow protection 934 for this application to protect the serving lab water system. The upstream potable water is iso-935 lated from lab water with its own ASSE 1013 device, thereby providing redundant in-series 936 backflow protection of the potable water supply. 937 938

3. For any case where a connection must be made directly to potable water system (no lab 939 water supply is available) an ASSE 1013 backflow prevention device and downstream 940 ASSE 1015 device shall be provided. 941

942 RATIONALE 943

Provision of redundant backflow protection is provided to minimize cross connection risk in the 944 event of device malfunction. Where the design of a tissue digester utilizes an internal code-945 compliant air-gap, redundant protection is not required. A below-rim air break is not equivalent. 946 947

4. Liquid effluent from tissue digesters shall be appropriately pH neutralized to levels in 948 conformance with sewage authority discharge regulations, preferably through use of on-949 board pH treatment equipment and monitoring. 950

951 RATIONALE 952


Page | 20

Wastes from tissue digesters produces elevated alkaline waste concentrations which can be 953 corrosive to piping and affect wastewater treatment. Treatment of elevated pH at the source 954 (such as through CO2 injection) is strongly preferred as it minimizes load (including biomass) 955 and maintenance issues through building pH treatment systems, but is not required where pH 956 treatment systems are appropriately designed to handle the waste stream. 957 958

5. Effluent shall not violate published waste water discharge characteristic limitations or 959 wastewater permit requirements unless prior written approval of the NIH project officer 960 and municipal sewer authority has been obtained and documented in project records. 961

962 a. Permission to discharge wastewater from tissue digesters (which typically contains 963

extremely high BOD, COD, TSS, TDS, and nitrogen levels) may be granted by mu-964 nicipal authorities with proper presentation of wastewater characteristics and actual 965 volume. This may entail additional wastewater treatment charges. To avoid misun-966 derstandings of actual wastewater load and unnecessary restrictions or charges, 967 throughput calculations establishing the estimated waste water volume, composition, 968 and maximum batch frequency shall be performed and discussed with the program 969 prior to approaching the sewer authority. 970 971

b. On-site treatment of hydrolysate to achieve acceptable discharge characteristics for 972 disposal through sewer systems, as well as use of any alternative applications of 973 disposing of hydrolysate shall only be undertaken with pre-approval of NIH, including 974 an outline of the proposed treatment approach and on-going maintenance require-975 ments. 976

977 RATIONALE 978

Treating effluent from tissue digesters to conform to wastewater requirements typically requires 979 a multi-process private on-site wastewater treatment system, which can be expensive to oper-980 ate, maintain, and impose a number of design and implementation concerns. The use of primary 981 treatment (such as settling/flocculation) and wastewater evaporation may be acceptable for 982 large systems where discharge approval cannot be obtained without such treatment, and is sub-983 ject to appropriate equipment selection for life cycle cost, however dry alternatives (such as mi-984 crowave, low-water/dry process alkaline hydrolysis etc.) may prove more cost effective in such 985 situations (providing such means are satisfactorily validated for the application and approved by 986 DOHS). Application of hydrolysate for fertilizers (whether below ground injection or above 987 ground applied) shall be subject to NIH DOHS approval. 988

989 6. Where tissue digester wastewater discharges to a private on-site waste water treatment 990

system (such as for remote applications not served by sanitary sewer), the A/E shall 991 confirm compatibility of the hydrolysate so as not to negatively affect operation of the on-992 site waste water treatment system. The A/E shall coordinate with users with regards to 993 throughput requirements to ensure accuracy of calculations for the maximum load. 994

995 RATIONALE 996

Cycle run times are substantially longer for prion/TSE disposal, however not all loads may be 997 TSE. Throughput directly impacts wastewater volume and duration. Excursions in waste water 998 discharge requirements can result in substantial penalties; therefore calculations must be accu-999 rate and consider the worst case actual operating conditions. 1000 1001

7. Slurry waste shall not be disposed through the building drainage systems. 1002 1003


Page | 21

RATIONALE 1004 Where the selected equipment discharges waste that may cool into slurry or otherwise solidify 1005 such wastes must be appropriately caked and disposed in an approved manner as solid waste 1006 so as not to block drainage systems. 1007

1008 8. The drain connection from the tissue digester shall be hard piped to the drainage system 1009

through an individually vented and automatically primed trap of at least 3-inch diameter, 1010 with a normally closed automated or manual isolation valve at the equipment connection. 1011 The inlet connection (vertical tailpiece leading into the trap) shall include a full size 1012 cleanout such that blockages in the trap may be readily cleared. A floor drain with an 1013 automatically primed trap shall be provided as a branch on the waste line serving the tis-1014 sue digester. 1015

1016 RATIONALE 1017

Not less than a 3-inch receiving waste piping is required to ensure transport of effluent and 1018 ready clearing of stoppages. 4-inch (or greater as required) should be used for larger systems. 1019 Hard connection with valving is to preclude odors and maintain sanitary conditions at the dis-1020 charge connection. The floor drain branch serves as a relief point in the event of wastewater 1021 system stoppage. 1022

1023 9. Liquid effluent from tissue digesters shall be cooled to 60 degrees C (140 degrees F) 1024

prior to discharge to the drainage system. 1025 1026

RATIONALE 1027 Compliance with discharge regulations. 1028

1029 10. Piping serving the tissue digester system shall be polypropylene with socket fusion joints 1030

to a point of dilution with the drainage system main, or CPVC with approved solvent ce-1031 ment joints. Refer to Chapter 6, Exhibit X6-3-A. (Link) 1032

1033 RATIONALE 1034

Polypropylene material is typically used for lab waste applications to the digester to ensure suit-1035 able chemical resistance with potential high temperature mild caustic waste. CPVC is also ac-1036 ceptable to the point of dilution and where the discharge is direct to sanitary. While CPVC is not 1037 typically approved in the DRM as a lab waste system material, it may be well-suited for this lim-1038 ited application. Corrosion resistant floor drain materials are used in the carcass disposal room 1039 as such rooms are exposed to frequent cleaning and disinfectant chemicals. 1040

1041 11. The need for automatic monitoring of effluent characteristics (such as COD and pH) 1042

shall be coordinated with the NIH. Monitoring equipment shall be selected for compati-1043 bility with the waste stream. 1044 1045

RATIONALE 1046 The need to monitor effluent characteristics may depend upon the location at which monitoring 1047 is elected to take place. For example, an extremely high BOD/COD level as obtained at the 1048 source may not be a significant issue if blended with sufficient wastewater prior to leaving cam-1049 pus. Characteristics of treatment processes (such as chemical oxidation and caustics) influence 1050 the accuracy and type of monitoring equipment required. It is recommended that the average 1051 empirical correlation between the typical effluent COD and BOD5 be established, as the COD 1052 reading may provide more effective direct reading for routine automatic monitoring. . Monitoring 1053 COD automatically may be advantageous as opposed to 5 day BOD. 1054


Page | 22

1055 8.5.10. Reagent Supply 1056

1057 1. Potassium hydroxide/ sodium hydroxide supplies shall be located in properly diked 1058

areas to contain chemical volume. The location of chemical drums to serve the sys-1059 tem shall be accessible for routine replacement. 1060

1061 1062

RATIONALE 1063 Required for control of spills or leaks. 1064 1065

2. Where reagent is piped from a remote location, the transfer lines shall be free drain-1066 ing and shall be double-contained and automatic leak monitored, except that single 1067 wall Type 304 or 316 seamless stainless steel welded joint piping systems (not less 1068 than Schedule 10) may be used for caustic, provided all portions of single wall piping 1069 (including penetrations) are arranged so as to be visible for routine inspection and 1070 located where not susceptible to damage or tampering. Remote reagent pipelines, 1071 tanks, and equipment shall be designed and installed in accordance with ASME 1072 B31.3 by a qualified chemical/process piping engineer and subject to NIH ORF ap-1073 proval. Double contained piping shall consist of a carrier tube of welded stainless 1074 steel, Schedule 80 PVC, CPVC, or polypropylene with socket fusion or butt fusion 1075 joints, and a containment tube of compatible thermoplastic or stainless steel. Local 1076 piping within the tissue digester room may be single wall polypropylene socket fusion 1077 or butt fusion, provide the piping is located so as to not be subject to damage. Ex-1078 cept where tubing is double-contained, chemical guards (tubing shields) shall be 1079 provided at all connections of pressurized reagent tubing to equipment wherever a 1080 leak in such connections could pose a safety hazard. 1081

1082 RATIONALE 1083

Durable and safe installation of caustic reagent. 1084 1085

3. Adequate heating shall be provided to prevent temperatures from dropping below 65-1086 degrees F where caustic (soda hydroxide and potassium hydroxide) are stored. 1087

1088 RATIONALE 1089

Caustic soda viscosity substantially increases above 19 degrees C (65 degrees F). If such con-1090 ditions cannot be met, consider the use of 25% solution. 1091

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