What is a Cross-Connection?

A cross-connection is defined as any actual or potential physical connection between the public water system and any source that could contaminate the public water supply (i.e. plumbing fixtures, water utilizing equipment, or sprinkler systems). If improperly protected, contamination can result when a backflow event occurs; allowing contaminates to reverse flow from the fixture/equipment back into the customer’s water service and/or the public water system.

Cross-connections, or potential cross-connections, are required to have devices installed to protect the quality of the water in the distribution system. These devices, called Backflow Prevention Devices, are installed on irrigation systems, fire sprinklers or other types of water uses where water could become contaminated. For example, sprinkler systems are required to have backflow devices that are designed to prevent contaminants from entering the water supply. These backflow devices are installed on the domestic water service lines to protect against both back-siphonage and back-pressure. Once water enters your irrigation system it is no longer potable (drinking) water as it can become contaminated with lawn chemicals and bacteria. If a backflow device is not installed properly, or is not functioning properly, contaminated water from the sprinkler system can be forced back into your home’s water supply and/or the public water system. This can happen via pressure from the blow-out activity (back-pressure) or from a loss of pressure in the public water system (back-siphonage). Testing on sprinkler systems are performed each spring when the system is turned on.

Backflow Education Videos

LLSWD Cross-Connection Control Program

The District is required to have a Cross-Connection Control Program in accordance with Washington Administrative Code (WAC) Chapter 246-290-490. The District’s responsibility for cross-connection control shall begin at the water supply source, storage, and distribution facilities, and end at the point of delivery to the consumer’s water system, which begins at the downstream end of the water meter. Recently the District updated their Cross-Connection Control Program through the adoption of Resolution 05-20. The purpose of the District’s Cross-Connection Control Program is to protect the public water system and public health from contamination via cross-connections.

Liberty Lake Sewer and District Resolution 05-20 – Cross Connection Control Policy

Approved Backflow Devices

Under WAC 246-290, backflow prevention assemblies that appear on the USC-Approved Assemblies List are acceptable for protection of the public water system.

Commercial Water Service Connections

  • DOH-approved reduced-pressure principle backflow assembly (RPBA) or reduced-pressure detector assembly (RPDA).

Commercial and Multifamily Irrigation System Connections

  • DOH-approved double check valve assembly (DCVA) or alternate device for the degree of hazard assessed by the District.

Commercial Fire Flow Connections

  • DOH-approved double check detector assembly (DCDA) or alternate device for the degree of hazard assessed by the District.

Single-family or Duplex Residential Irrigation Systems

  • DOH-approved double check valve assembly (DCVA) or alternate device for the degree of hazard assessed by the District.

Installation Requirements

For installation of backflow assemblies outside it must be performed by a Washington State Certified Backflow Assembly Tester (BAT). For installations of backflow assemblies inside a building it must be performed by a plumber certified in Washington State.  Backflow assemblies must be tested immediately following installation.

LLSWD Testing Requirements

To ensure that the water system is properly protected and that all system users receive safe drinking water, the District requires that all customers, residential, multifamily and commercial, test their backflow device(s) annually. After a backflow device is installed, initial testing is required to ensure proper function of the device and protection of the water system. Testing must be performed by a Washington State certified Backflow Assembly Tester (BAT) and must be done at least once a year. If repairs are required, they usually can be completed at the time of the backflow test. After a successful test is completed, Backflow Assembly Testers submit a test report to the District. The test reports are the District’s method of confirming that backflow assemblies have been maintained and function properly so the system is safe for all users.

When your device has been tested, you or your tester should send a copy of the report to the District: backflow@libertylake.org

Download the LLSWD Test Report (the District will accept alternative test reports from testers)

Certified Backflow Assembly Testers

Backflow Assembly Testers

Testing prices vary, and to assist our customers we have put together a list of Washington State Certified Backflow Assembly Testers. If you are a Washington State Certified Backflow Assembly Tester and want to be added to the District’s list please contact the District at (509) 922-5443 or at backflow@libertylake.org.

List of Washington State Certified Backflow Assembly Testers

Customers don’t have to use one of the testers identified on our list. Any WA State Certified Backflow Assembly Tester can perform the test. Many landscape and sprinkler companies have BAT’s on staff that can perform the test. So, if you have one of those companies you like or use inquire with them as well. Unfortunately the District cannot endorse or recommend any particular company, however since prices vary our recommendation is to call a few for quotes.

Backflow Assembly Testing Schedule

The District requires annual backflow tests on all residential, multifamily and commercial customer connections.

The District distributes three (3) Backflow Notice Letters to inform and remind customers of the testing requirements:

  • FIRST NOTICE will be included in the monthly water/sewer bill sent in April
  • SECOND NOTICE will be included in the monthly water/sewer bill sent in May
  • FINAL NOTICE will be included in the monthly water/sewer bill sent in June
    • DEADLINE: June 30 (annually)**

**If the District has not received the backflow test report by June 30 the District will shut off the water service (which includes a shut-off fee) until a test report is received.

When your device has been tested, you or your tester should send a copy of the report to the District.

Download the LLSWD Test Report (the District will accept alternative test reports from testers)

The importance of cross-connection control is to protect the quality and safety of our water. We appreciate your understanding and support of clean, safe drinking water. For more information please contact the District at (509) 922-5443 or at backflow@libertylake.org.

Additional Resources

Washington Administrative Code

Washington State Department of Health

Spokane Regional Cross Connection Control Chapter

Washington Certification Services

Cross-Connection Control Brochures – Provided by Pacific Northwest Section American Water Works Association