Chemical and Chemical and Backflow Backflow

PreventionPreventionRyan Bushman – Inman InterwestRyan Bushman – Inman Interwest

Michael Moss – Division of Drinking Michael Moss – Division of Drinking WaterWater

Utah Nursery & Landscape Utah Nursery & Landscape AssociationAssociation

January, 2010January, 2010

Purpose:Purpose:Protect the Protect the

drinking water drinking water supply!supply!

Definitions:Definitions: BackflowBackflow - - The undesirable reversal of The undesirable reversal of

flow of water or mixtures of water and flow of water or mixtures of water and other liquids, gasses or other other liquids, gasses or other substances into the drinking water substances into the drinking water system. Occurs due to a pressure system. Occurs due to a pressure differential between two points within a differential between two points within a continuous fluid system.continuous fluid system.

Definitions:Definitions: Cross ConnectionCross Connection - Any actual or - Any actual or

potential connection between the potential connection between the drinking water system and any other drinking water system and any other source or system through which it is source or system through which it is possible to introduce into the system possible to introduce into the system any used water, industrial fluid, gas or any used water, industrial fluid, gas or substance other than the intended substance other than the intended potable water.potable water.

Definitions:Definitions: ContaminateContaminate – Any substance – Any substance

introduced into a drinking water system introduced into a drinking water system which creates a threat to public health.which creates a threat to public health.

Definitions:Definitions: PollutantPollutant – Any substance introduced – Any substance introduced

into a drinking water system which into a drinking water system which does NOT create a threat to public does NOT create a threat to public health, but adversely and unreasonably health, but adversely and unreasonably affects the aesthetic quality of the affects the aesthetic quality of the water. water.

Definitions:Definitions: Degree of HazardDegree of Hazard – The threat to – The threat to

public health from a contaminate public health from a contaminate (health) or pollutant (non-health) (health) or pollutant (non-health) introduced by a cross connection into introduced by a cross connection into the drinking water system.the drinking water system.

Installation Installation RequirementsRequirements

Available Plumbing CodesAvailable Plumbing Codes ICC - International Plumbing Code ICC - International Plumbing Code IAPMO - Uniform Plumbing codeIAPMO - Uniform Plumbing code BOCA National Plumbing CodeBOCA National Plumbing Code NAPHCC National Standard Plumbing CodeNAPHCC National Standard Plumbing Code ANSI A40 National Plumbing CodeANSI A40 National Plumbing Code State Written Plumbing CodeState Written Plumbing Code ……………………..

Utah Plumbing CodeUtah Plumbing Code State of Utah has adopted the 2006 State of Utah has adopted the 2006

International Plumbing Code (IPC).International Plumbing Code (IPC). The State of Utah has 64 amendments The State of Utah has 64 amendments

to the current IPC.to the current IPC. The 2009 IPC requires Legislative The 2009 IPC requires Legislative

Action and approval before adoption. Action and approval before adoption. This may not be in effect until July 1, This may not be in effect until July 1, 2010.2010.

Installation HazardsInstallation HazardsLack of KnowledgeLack of Knowledge

CustomersCustomersInspectorsInspectorsCouncils and BoardsCouncils and BoardsYour own personnelYour own personnel

Connections for Connections for Irrigation System Irrigation System

WaterWater Secondary or irrigation supply onlySecondary or irrigation supply only

Culinary or drinking water supply onlyCulinary or drinking water supply only

Combination of the secondary/irrigation Combination of the secondary/irrigation water during the normal season with water during the normal season with drinking water connected for early and drinking water connected for early and late season irrigationlate season irrigation

Secondary Irrigation Secondary Irrigation Water OnlyWater Only

No protectionNo protection is required when the is required when the source is separate from and NOT source is separate from and NOT connected or able to be connected to connected or able to be connected to drinking water.drinking water.

Drinking Water OnlyDrinking Water Only The adopted plumbing code, Section The adopted plumbing code, Section

608-16-5 REQUIRES that the lawn 608-16-5 REQUIRES that the lawn irrigation system be protected against irrigation system be protected against backflow by an backflow by an atmospheric vacuum atmospheric vacuum breakerbreaker, a , a pressure vacuum breaker pressure vacuum breaker assemblyassembly or a or a reduced pressure reduced pressure principle backflow prevention assemblyprinciple backflow prevention assembly..

Secondary Irrigation Secondary Irrigation Water Supplemented Water Supplemented with Drinking Water with Drinking Water Separate supply risersSeparate supply risers Culinary line will be protected by a Culinary line will be protected by a

reduced pressure backflow preventerreduced pressure backflow preventer Swing joint connected to irrigation lineSwing joint connected to irrigation line Connected to either pressurized Connected to either pressurized

irrigation irrigation OROR culinary, but culinary, but not both at not both at the same timethe same time

SPRINKLING SYSTEM

PRESSURE IRRIGATION WATER

RP

SWING JOINT CONNECTION

CITY WATER

SPOOL CONNECTION SYSTEM

Dual Irrigation Connections

Swing Connection

Irrigation Water Source

Drinking Water Source

Dual Irrigation Connections

Reduced Pressure Principle Backflow

Preventer

Swing Connection

Chemical InjectionChemical Injection FertilizersFertilizers PesticidesPesticides HerbicidesHerbicides

MethodsMethods…….……. PumpedPumped Venturi or aspiratorsVenturi or aspirators TanksTanks

CHEMICAL FEEDER

CODE COMPLIANT BACKFLOW

PREVENTION ASSEMBLY

VALVE BOX

The Utah plumbing code, Section 608-The Utah plumbing code, Section 608-16-5, REQUIRES where ‘chemicals’ are 16-5, REQUIRES where ‘chemicals’ are introduced into the system, the water introduced into the system, the water supply shall be protected against supply shall be protected against backflow by a backflow by a reduced pressure reduced pressure principle backflow prevention principle backflow prevention assembly.assembly.

Chemical InjectionChemical InjectionHow does this How does this

work?work?

VENTURI EFFECT

STATIC CONDITION

GAUGE PRESSURE EQUAL

0 200 0 200 0 200

VENTURI EFFECTDYNAMIC CONDITION

GAUGE PRESSURE DROPS

VELOCITY INCREASES

0 0 0200 200 200

HIGH VELOCITY FLOW VACUUM POINTS

NEGATIVE PRESSURE

VENTURI CONDITIONDYNAMIC CONDITION - HIGH FLOW RATE

Chemical InjectionChemical InjectionHow Can This How Can This

Process Harm Us?Process Harm Us?

0 0 0200 200 200

Protection AvailableProtection Available Backflow PreventersBackflow Preventers

Air GapAir Gap Reduced Pressure Principle Backflow Reduced Pressure Principle Backflow

Prevention AssemblyPrevention Assembly Double Check Valve Backflow Double Check Valve Backflow

Prevention AssemblyPrevention Assembly Pressure Vacuum Breaker Backflow Pressure Vacuum Breaker Backflow

Prevention AssemblyPrevention Assembly Spill Resistant Vacuum Breaker Spill Resistant Vacuum Breaker

Backflow Prevention AssemblyBackflow Prevention Assembly

Backflow PreventersBackflow Preventers Air GapAir Gap - 2 times the pipe diameter - 2 times the pipe diameter 1” minimum1” minimum 1 ½” pipe has a 3” air gap1 ½” pipe has a 3” air gap If the pipe is less than 2 pipe If the pipe is less than 2 pipe

diameters from a side wall, then the diameters from a side wall, then the air gap is 3 times the pipe diameterair gap is 3 times the pipe diameter

If an 1 ½” pipe is less than 3” from a If an 1 ½” pipe is less than 3” from a side wall, the air gap would be 4 ½”side wall, the air gap would be 4 ½”

Backflow PreventersBackflow Preventers Reduced Pressure Principle Reduced Pressure Principle

Backflow Prevention AssemblyBackflow Prevention Assembly Cannot be used in a pit or vaultCannot be used in a pit or vault Must have 12” of clearance all aroundMust have 12” of clearance all around Air gap must be maintained at the vent portAir gap must be maintained at the vent port Not subject to water hammerNot subject to water hammer High HazardHigh Hazard Backsiphonage and backpressureBacksiphonage and backpressure

Reduced Pressure Principle Backflow Prevention Assembly

RELEIF PORT (1)

TEST PORTS

(4)

ISOLATION VALVES (2)

MAINTAIN AS AN ASSEMBLY

GOOD INSTALLATION

PROBLEM INSTALLATIONS

Installed Below Grade

Installed In Ceiling and is

NOT Accessible

Backflow PreventersBackflow Preventers Double Check Valve Backflow Double Check Valve Backflow

Prevention AssemblyPrevention Assembly Low hazard onlyLow hazard only……

not allowed for Utah lawn irrigation not allowed for Utah lawn irrigation system installations per current code system installations per current code (since 2005)(since 2005)

May be installed in a pit or vaultMay be installed in a pit or vault Must have 12” of clearance for testing and Must have 12” of clearance for testing and

repairrepair Backsiphonage and backpressureBacksiphonage and backpressure

Backflow PreventersBackflow Preventers Pressure Vacuum Breaker and SpillPressure Vacuum Breaker and Spill

Resistant Vacuum Breaker AssemblyResistant Vacuum Breaker Assembly Vertical installations onlyVertical installations only 12” above the highest piping or point of use12” above the highest piping or point of use Shall not be installed in a pit or vaultShall not be installed in a pit or vault 12” of clearance for testing and repairs12” of clearance for testing and repairs No backpressure (backsiphonage only)No backpressure (backsiphonage only) High HazardHigh Hazard

PROBLEM INSTALLATION

PROBLEM INSTALLATIONS

Backflow PreventersBackflow Preventers Atmospheric Vacuum Breaker Atmospheric Vacuum Breaker

6” above the highest piping or point of 6” above the highest piping or point of useuse

No downstream valvesNo downstream valves No more that 12 hours of continuous useNo more that 12 hours of continuous use No pits or vaultsNo pits or vaults High HazardHigh Hazard

PROBLEM INSTALLATION

Backflow PreventersBackflow Preventers Hose Bib Vacuum BreakerHose Bib Vacuum Breaker

Must be non-removable typeMust be non-removable type Hose bibs onlyHose bibs only Must be drained for winter (in freezing Must be drained for winter (in freezing

climates)climates) Majority of all backflow incidents could Majority of all backflow incidents could

be prevented with a hose bib vacuum be prevented with a hose bib vacuum breakerbreaker

Annual TestingAnnual Testing Reduced Pressure Principle Reduced Pressure Principle

Backflow Prevention AssemblyBackflow Prevention Assembly Double Check Valve Backflow Double Check Valve Backflow

Prevention AssemblyPrevention Assembly Pressure Vacuum Breaker Backflow Pressure Vacuum Breaker Backflow

Prevention AssemblyPrevention Assembly Spill Resistant Pressure Vacuum Spill Resistant Pressure Vacuum

Breaker Backflow Prevention Breaker Backflow Prevention AssemblyAssembly

Annual CheckAnnual Check Visually check all high hazard air Visually check all high hazard air

gapsgaps

Devices:Devices: atmospheric vacuum atmospheric vacuum breakers, hose bib vacuum breakers, hose bib vacuum breakers, etc.,(visual inspection)breakers, etc.,(visual inspection)

Dual check Dual check isis NOTNOT a double a double check valve assemblycheck valve assembly

ClimateClimate Freezing must be addressedFreezing must be addressed Drained in winter( ball valves left in the half Drained in winter( ball valves left in the half

open position)open position) Test cocks opened and left open to drain Test cocks opened and left open to drain

water between the check valveswater between the check valves Above ground year round use must be Above ground year round use must be

heated and protectedheated and protected Socio-economic Socio-economic climateclimate (theft or (theft or

vandalism)vandalism)

Irrigation HazardsIrrigation Hazards No installation or improper installationNo installation or improper installation

No hose bib vacuum breakerNo hose bib vacuum breaker Valves on the downstream side of an AVBValves on the downstream side of an AVB AVB not installed 6” above the highest point of AVB not installed 6” above the highest point of

useuse PVB installed with backpressure PVB installed with backpressure Double check valves installed on high hazardDouble check valves installed on high hazard Devices installed where assemblies should beDevices installed where assemblies should be No annual testingNo annual testing

QUESTIONS?QUESTIONS?