Frequently Asked Questions About the Cross Connection Control Program

Heated water expands. Without an expansion tank, the water heater pressure relief valve can open, spilling water onto the floor or down the drain. It is water you paid to heat.

The pressure relief valve on the water tank is an emergency control and is not intended to operate on a regular basis. If it fails, a system pressure can build to dangerous levels. Elevated system pressure can damage your water heater, cause fittings to leak, toilets to run and faucets to drip.

Installing a heater expansion tank will allow for thermal expansion of the water and will control the pressure it generates and keep it within a normal, safe operating range; well below the emergency setting of an emergency relief valve.

The backflow assembly will require an annual inspection by a certified tester. The City of Mount Shasta retains all past testing information and, as a customer service, can provide previous tester’s contact information. The City will mail an instructional letter and a Test and Maintenance Report Form approximately 90 days prior to the current expiration date of your backflow device inspection.

Failure to renew your valid test date can result in termination of your water service by the City.

All water users benefit from an active, on-going cross connection control program that includes the installation of backflow preventer. Maintaining the quality and safety of our water is of the utmost importance to the City of Mount Shasta. California requires all public water systems to operate an on-going program to protect the public water supply from contamination from possible cross connections. The most effective method for the water utility to meet this requirement is to require customers to install a backflow preventer on the main supply line to their property or facility, thus protecting the community water system from any cross connections that may be present inside the customer’s plumbing system.

The need for cross-connection control exists in all types of premises, whether residential, commercial or industrial. Backflow prevention devices help protect the public safety by preventing potable water contamination in such critical areas as municipal water systems, food processing plants, medical and dental water supplies, and many industrial applications.

As a condition of service all new residential homes and renewals must be fitted with an appropriate backflow prevention device in accordance with the Rules and Regulations of the City.

An approved testable backflow prevention device must be installed on all, commercial, industrial, irrigation systems, fire suppression systems, residential apartment buildings which contain five or more individual units, are multileveled and are jointly metered residential, non-residential service lines. A service line providing water to a farm for any purpose other than the residence is also considered to be non-residential and requires the installation of a backflow preventer device.

After the backflow prevention device is installed and water service initiated, an initial test must be performed within 30 days by a certified backflow tester.

Backflow preventers are mechanical plumbing devices installed in a plumbing system to prevent water from flowing backward in the system. A properly installed, tested and maintained backflow preventer assembly at the water service entrance to a building or property can reliably prevent a cross connection into the community water system.

Any pipe, valve, fixture, etc., in a drinking water plumbing system that may allow the drinking water within the system to become contaminated or questionable in quality. Cross connections can either be eliminated or protected by an air gap or mechanical backflow preventer.

The City of Mount Shasta, in accordance with Title 17 of the California State Code of Regulations, and the California State Water Resources Control Board, is required to identify and eliminate any cross-connections.

Backflow is the undesirable reversal of the flow of water from its intended direction in any pipeline or plumbing system. Backflow occurs as a result of a “cross connection” within the water system. A cross connection can occur when there is any actual or potential connection between a potable water system and another water source or system.

The backflow preventer assembly is installed to protect the public water supply against possible hazards in the customer’s plumbing system. The actual or potential cross connection belongs to the property owner and not to regulatory officials or the water utility. Once the water goes beyond the meter, water quality could be altered. The water utility does not want the water back, nor do the water customers want to purchase used water. If a backflow preventer is required to keep the water safe, then the person who created the cross connection (actual or potential) should purchase, install and maintain the backflow preventer as a condition of service.