All pesticide operational areas shall implement procedures to prevent backflow incidents from contaminating potable water supplies. Potable water supply lines may not be connected to process water lines, chemical lines, or equipment unless backflow prevention is installed. Backflow prevention shall consist of one of the following:

1. (1) A reduced-pressure principle device which meets the American Water Works Association Standard C511-89 (September 1, 1990) for backflow prevention devices; or

2. (2) Air gap separation. Air gap is a physical separation between the free flowing discharge end of a water pipeline and an open or nonpressurized receiving vessel. To have an acceptable air gap, the end of the discharge pipe must be located a distance of at least twice the diameter of the pipe above the topmost rim of the receiving vessel.

   Reference: AWWA Standard for "Reduced-Pressure Principle Backflow-Prevention Assembly," American Water Works Association, effective September 1, 1990. Copies may be obtained from the American Water Works Association, 6666 West Quincy Avenue, Denver, Colorado 80235; $12 per copy plus $2.95 shipping and handling.

Source: 18 SDR 49, effective September 15, 1991.

General Authority: SDCL 38-21-15 , 38-21-15.1 , 38-21-51.

Law Implemented: SDCL 38-21-15.