Why are irrigation systems considered to be hazardous to the water system?

Irrigation systems include but are not limited to agricultural, residential, and commercial applications. The VDH classifies lawn sprinkler systems and irrigation systems as a high hazard; sprinklers, bubbler outlets, emitters, and other equipment are exposed to substances such as fertilizers, fecal material from pets or other animals, pesticides, or other chemical and biological contaminants and pollutants. Sprinklers may remain submerged underwater after use or storms. Should the water system pressure suddenly decrease, such as in the case of a water main break, line flushing, or during a major fire involving multiple fire hydrants, these harmful substances can be back-siphoned into the water distribution system. They may be subject to various onsite conditions such as additional water supplies, chemical injection, booster pumps, and elevation changes. All of these conditions must be considered when determining backflow protection. Some hazards relating to irrigation systems are:

Fertilizers: Ammonia salts, ammonia gas, phosphates, potassium salts.

Herbicides: 2,4-D, dinitrophenol, 2,4,5-T, T-pentachlorophenol, sodium chlorate, borax, sodium arsenate, methyl bromide

Pesticides: TDE, BHC, lindane, TEPP, parathion, malathion, nicotine, MH and others

Fecal matter: Animal (domestic and non-domestic)

Show All Answers

1. Why does the City of Petersburg Public Utilities Division have a Backflow Prevention & Cross Connection Control Program?
2. What is a cross-connection?
3. What is backflow?
4. What is backpressure?
5. What is backsiphonage?
6. Why is backflow a concern to the public?
7. Are all residential homes required to have backflow assemblies?
8. Why are irrigation systems considered to be hazardous to the water system?
9. What type of backflow prevention assemblies are allowed in irrigation systems?
10. How do I know if I have a backflow prevention assembly?
11. What kind of buildings need backflow prevention assemblies?
12. Is there a minimum height that the backflow assembly must be installed?
13. When is a plumbing permit required?
14. Can a backflow device be removed?
15. How frequently does a backflow prevention assembly have to be tested?
16. How much will the inspections/maintenance cost?
17. What credentials are required to inspect and test a backflow prevention assembly?
18. Will I receive notification when to perform my test?
19. What if I don’t receive a letter?
20. What can I do with my test report?
21. Abbreviations