Important Information for Do-It-Yourself Irrigation System Installers.

HOME IRRIGATION SAFETY

Don't let your Irrigation System Contaminate the Water you Drink

BACKFLOW PREVENTION ALTERNATIVES FOR HOME IRRIGATION SYSTEMS
Irrigation systems make watering lawns and gardens easier and save time, BUT, water that may be contaminated by weed killers and/or fertilizers can be backsiphoned (backflow) into your drinking water. Irrigation systems not protected by approved backflow prevention assemblies could endanger the health of a household, neighborhood or community.
ALL IRRIGATION SYSTEMS., new or existing...MUST BE EQUIPPED with an approved backflow prevention assembly. Only properly installed, state-approved backflow prevention assemblies meet the plumbing code and provide health protection for your family and neighbors. Your local water utility can give you a free list of state-approved assemblies and certified testers.
Please Note: ALL IRRIGATION SYSTEMS supplied by public water systems REQUIRE A PLUMBING PERMIT before installation. All piping and materials upstream of (before) the backflow prevention assembly must be of a type which is approved by the STANDARD PLUMBING CODE.

THREE TYPES OF BACKFLOW PREVENTION ASSEMBLIES:

1. PRESSURE VACUUM BREAKER (PVB)

Sophisticated
Versatile
Requires annual testing by a certified tester

2. DOUBLE CHECK VALVE ASSEMBLY (DCVA)

No longer allowed
Low or non-health hazard systems only. . lawn irrigation systems are considered High Hazard.

3. REDUCED PRESSURE BACKFLOW ASSEMBLY (RPBA)

Usually most expensive
Most complex
Allows for application of fertilizer or other chemicals into irrigation system.
(No other type has this approval)
Requires annual testing by a certified tester.

FREEZE PROTECTION

All backflow prevention assemblies need to be protected from freezing. Here are three methods used to protect backflow preventers:

Shut off water supply to backflow preventer. Open both inlet and outlet valves. Open all test cocks. (This method only works on those systems that are not being used in winter months.)
Leave Your water running continuously.
Wrap your backflow preventer with insulation. Usually wrapping alone does not protect the assembly unless some type of heat is provided. (Heat tape, light bulb, etc.)

PVB...PRESSURE VACUUM BREAKER ASSEMBLY

Only one PVB required to serve the whole system; control valves can be located downstream of (after) the PVB. (Maximum size = 2").
PVB's must be installed a minimum of 1 foot (12") above the highest point of water they serve.
PVB's must be tested by a Certified Backflow Assembly Tester ...at the time of installation ...annually...when moved or repaired.
No chemical or fertilizer may be introduced into an irrigation system equipped with PVB's.
No pumps or back pressure on downstream side of (after) a PVB.

DCVA...DOUBLE CHECK VALVE ASSEMBLY
[NOTE: This assembly no longer allowed on Lawn Irrigation systems - see current plumbing codes]

Only one DCVA required to serve the whole system; control valves can be located downstream of the DCVA.
DCVA should be installed a minimum of one foot (12") above ground level.
Some water suppliers may allow the DCVA to be installed below ground, check for proper clearance on all sides of the assembly.
DCVA must be tested by a Certified Backflow Assembly Tester...when installed ...annually ...when moved or repaired.
No chemical or fertilizer may be introduced into an irrigation system equipped with DCVA's.

RPBA....REDUCED PRESSURE BACKFLOW ASSEMBLY

Only one RPBA required to serve the whole system; control valves can be located downstream of the RPBA.
RPBA's must be installed a minimum of one foot (12") above ground level.
RPBA's must be tested by a Certified Backflow Assembly Tester...when installed ...annually ...when moved or repaired.
In an RPBA equipped system, fertilizer and other agricultural chemicals may be introduced downstream of (after) the RPBA.

Important Information for Do-It-Yourself Irrigation System Installers

Some laws and regulations regarding backflow protection and approval of type of pipe used may vary depending upon local requirements. For more specific information, we advise you to contact your local water supplier at:

(local water purveyor address, etc.)

This pamphlet initially prepared by:
Pacific Northwest Section American Water Works Association Cross Connection Control Committee.
posted by Les O'Brien, CET
12/06/97 - rev. 07/15/2007

Important Information for Do-It-Yourself Irrigation System Installers.

HOME IRRIGATION SAFETY

Don't let your Irrigation System Contaminate the Water you Drink

THREE TYPES OF BACKFLOW PREVENTION ASSEMBLIES:

This pamphlet initially prepared by: Pacific Northwest Section American Water Works Association Cross Connection Control Committee. posted by Les O'Brien, CET 12/06/97 - rev. 07/15/2007

This pamphlet initially prepared by:
Pacific Northwest Section American Water Works Association Cross Connection Control Committee.
posted by Les O'Brien, CET
12/06/97 - rev. 07/15/2007