Okla. Stat. tit. 2, § 2-20-51: Irrigation systems

A. All irrigation systems into which any animal waste will be

injected shall be equipped with one or both of the following

systems:

1. An antipollution system, approved by the State Board of

Agriculture, capable of preventing the backflow of animal waste into

the groundwater. The system shall include a safety check valve with

a removable inspection port, anti-syphon vent, and low-pressure

escape drain. An interlock device shall be installed on pumps that

pump the animal waste so that if a fresh water irrigation pump shuts

down, the pump that pumps the animal waste will also immediately

shut down, preventing the chance of leakage past the check valve; or

2. A system which provides for a complete and total

disconnection between the flow of fresh water and the flow of animal

waste. The system shall be capable of a manual disconnection

between fresh water and the animal waste.

B. The Oklahoma Department of Agriculture, Food, and Forestry

shall make annual on-site inspections examining the operative status

of the check valves and interlock devices.

C. The operator of the irrigation system shall be responsible

to ensure:

1. That the valves and interlock devices remain operative

between annual inspections by the Oklahoma Department of

Agriculture, Food, and Forestry; or

2. Complete disconnection from fresh water when introducing

animal waste into the system.