(a) A connection between a drinking water supply system and any part of a wastewater treatment facility or collection system must be made through an air gap or a reduced-pressure backflow assembly (RPBA) in accordance with American Water Works Association (AWWA) Standard C511-97 or AWWA Manual M14.(b) Each RPBA must be tested and passed annually by a commission licensed backflow prevention assembly tester. If an RPBA fails an annual test, it must be repaired or replaced, and then retested by a commission licensed backflow prevention assembly tester.(c) RPBA test results and maintenance records must be retained at the wastewater treatment facility for at least three years.(d) Vacuum breakers are required on all potable water spigots.