Protect Your Ground Water When You Chemigate

Do you inject pesticides into your irrigation system? If so, then the California Department of Pesticide Regulation would like to remind you that safety devices are required to prevent ground water contamination.

Ground Water Contamination Can Occur If:

• Irrigation water containing chemicals flows back into the well
• The chemical injection pump continues to run after shut down of the well pump
• Chemicals overflow from the chemical supply tank onto surrounding soil

Prevention is the Key to Protection
Prior to injecting any pesticide, read the label to check if it can be applied through an irrigation system and then check for required backflow prevention components (A-H) that prevent backflow of a pesticide to a private well. Please contact your Agricultural Commissioner (California Department of Food and Agriculture page opens in a new browser window) for additional requirements or designs that comply.

Remember:

Read all chemigation instructions on the label before injecting the chemical

Identify all components of your system and make sure they are functioning properly

Monitor your system during chemigation

Required Chemigation Components
(A) Mainline Single Check Valve
(B) Low Pressure Drain
(C) Air/Vacuum Relief Valve
(D) Pressure Switch
(E) Interlocking System Controls
(F) Solenoid Operated Valve
(G) Chemical Injection Pump
(H) Injection Line Check Valve

Component Descriptions

(A) Mainline Single Check Valve:

Prevents backflow to well

Spring-loaded, positive closing action

Watertight seal (not metal to metal)

Install between well & chemical injection line

(B) Low Pressure Drain:

Drains minor check valve leakage away from well

Install at bottom side of irrigation pipeline, upstream of mainline check valve

(C) Air/Vacuum Relief Valve:

Prevents backsiphonage

Can be combined with inspection port

Install upsteam of mainline check valve

(D) Pressure Switch:

Stops well pump when water pressure decreases

Install in irrigation pipeline or well pump

(E) Interlocking System Controls:

Automatically shuts off chemical injection pump when well pump stops

Solenoid valve & chemical injection pump interlocked with well pump

Install between chemical injection pump and well pump

(F) Solenoid Operated Valve:

Prevents chemical withdrawl when irrigation system shuts down

Install on intake side of chemical injection pump & connect to interlocking system controls

(G) Chemical Injection Pump:

Assures proper chemical injection rate

Constructed of chemically resistant materials

Connect to interlocking system controls

(H) Injection Line Check Valve:

Prevents flow of fluid back towards chemical injection pump

Automatic, quick-closing check valve

Constructed of chemically resistant materials

Install between irrigation pipeline & chemical injection pump

If your well is connected to a municipal water system, contact your local health department to assure compliance.

Check with your Agricultural Commissioner (California Department of Food and Agriculture page opens in a new browser window) for additional components or designs that fulfill backflow prevention compliance.