Rule 17.38.305 - CROSS-CONNECTIONS: REGULATORY REQUIREMENTS(1) A cross-connection on a public water supply system must be eliminated by the disconnection of the cross-connection whenever reasonably practicable. Whenever elimination of a cross-connection is not reasonably practicable and the cross-connection creates a health or non-health hazard, the hazard must be eliminated by the insertion into the piping of an approved backflow prevention assembly or device in accordance with (2).(2) For the cross-connections identified below, the following types of approved backflow prevention assemblies or devices must be used:(a) A health hazard created by a cross-connection that may be subject to back pressure must be eliminated by an approved reduced pressure principle backflow prevention assembly (RP) or an air-gap.(b) A health hazard created by a cross-connection that may be subject to back siphonage, but not subject to back pressure, must be eliminated by an approved air-gap, pressure vacuum breaker assembly (PVB), spill-resistant pressure vacuum breaker assembly (SVB), atmospheric vacuum breaker (AVB), or a reduced pressure principle backflow prevention assembly (RP).(c) A non-health hazard created by a cross-connection that may be subject to back pressure and back siphonage must be eliminated, at a minimum, by an approved double check valve assembly (DC). This cross-connection condition may also be eliminated by an air-gap or by an approved reduced pressure principle backflow prevention assembly (RP). (d) A non-health hazard created by a cross-connection that may be subject to back siphonage, but is not subject to back pressure, must be eliminated, at a minimum, by an approved double check valve assembly (DC), pressure vacuum breaker assembly (PVB), spill-resistant pressure vacuum breaker assembly (SVB), or an atmospheric vacuum breaker (AVB). This cross-connection condition may also be eliminated by an air-gap or by an approved reduced pressure principle backflow prevention assembly (RP). (3) Backflow prevention assemblies and devices must be approved by the department.(4) A backflow prevention assembly or device must be installed and maintained, at a minimum, in accordance with the manufacturer's specifications.(5) This rule applies to piping between water systems outside of any building and to piping within any building, including cross-connections in plumbing systems. (6) The department may not approve a plan for the construction of a public water supply system containing provisions for cross-connection unless provisions for the protection of the public water supply are demonstrated in the plan.Mont. Admin. r. 17.38.305
NEW, 1998 MAR p. 958, Eff. 4/17/98; AMD, 2012 MAR p. 1141, Eff. 6/8/12; AMD, 2024 MAR p. 253, Eff. 2/10/2024AUTH: 75-6-104, MCA; IMP: 75-6-104, MCA