Water purveyors, such as the Carroll County Water Authority, are required under the Federal Safe Drinking Water Act of 1974 and the statutes of the State of Georgia Rules for Safe Drinking Water to implement and maintain a Cross-Connection Control Program (also known as a Backflow Prevention Program) to protect the public potable drinking water supply. The purpose of this program is to protect the public from contaminated water or other substances flowing back into CCWA’s water distribution system. CCWA works 24 hours a day to maintain safe, high quality water flowing to each and every customer, and the Cross-Connection Control Program is in place to reduce the risk of contamination of the potable water by the plumbing system of a downstream user.
Residential services (meters serving homes) are protected by a non-testable residential dual check valve installed by CCWA. This valve, located on the customer-side of the meter, allows water to flow from the water distribution main into the customer’s plumbing but does not allow the water to flow back into the water main.
Commercial and Industrial services are required to install and maintain a testable backflow prevention assembly on their side of the water meter. The type of business, specific water uses onsite, and existing plumbing protection in place are all factors used to determine what type of backflow prevention assembly is required. The most common testable backflow preventer is a Double Check Valve Assembly (DCVA). In cases where a higher level of protection is needed, the customer is required to install a Reduced Pressure Backflow Preventer (RPBP or RPZ). Backflow prevention assemblies must be tested upon installation, whenever they are cleaned or repaired, and once a year.
Backflow prevention assembly tests are performed by a certified tester. CCWA does not endorse or recommend any specific backflow tester or testing company. Many plumbers are certified testers; however, it is not required that certified testers be licensed plumbers.
Whenever a backflow prevention device or assembly is installed on the customer’s side of the water meter, a condition known as a “closed” plumbing system is created. In an open plumbing system, where there is no type of check valve or backflow preventer in the plumbing system, water pressure may bleed back into the distribution mains as the pressure increases in the building plumbing. A closed plumbing system, the water is trapped in a fixed volume of piping and pressure may build in the piping when the water is heated (such as by a water heater) resulting in a condition called thermal expansion. The increased pressure in the pipes may cause faucets to drip, toilets to run in the middle of the night, the water heater “pop-off” to flow, or water pipes to leak or come apart. The plumbing code states that a device for controlling pressure is required where a backflow prevention device, check valve or other device is installed on a water supply system utilizing storage water heating equipment such that thermal expansion causes increase in pressure.