N.D. Admin. Code § 7-10-02-05
A spring loaded, chemically resistant check valve having a minimum opening pressure of ten pounds per square inch [69 kilopascals] must be located at the injection port of the irrigation system.
History: Effective October 1, 1988.
General Authority: NDCC 4.1-35-03
Law Implemented: NDCC 4.1-35-02, 4.1-35-03