A cross-connection is any connection between a safe drinking water system and any other untested water source, system, or equipment that may contain unsafe substance. LACWD’s public water systems are designed to keep water flowing in one direction—from LACWD’s water main to the customers’ connections. When an undesirable condition known as backflow occurs, water is allowed to flow in the opposite direction and may bring contaminants or pollutant into the public drinking water supply through a cross-connection.
Backflow is caused by a backsiphonage or a backpressure condition in the public water system. Backsiphonage may occur when the pressure in the public water system drops below atmospheric pressure and creates a vacuum that may pull unsafe substance into the public water supply. Backpressure may occur when the pressure from a private water system becomes greater than the pressure in the public water system. This difference in pressure may allow unsafe substance from the private water system to enter the public water system. Approved backflow prevention assemblies are designed to prevent backflow of contaminants or pollutants from entering the public water systems.
In order to protect our public water systems from potential contamination, LACWD has implemented a Cross-Connection Control and Backflow Prevention Program (Program) in accordance with the California Administrative Code, Title 17. The program consists the following elements:
When backflow protection is necessary, the customer will be required to install an approved backflow prevention assembly and to have it tested on an annual basis by a certified tester. LACWD will send a written notice and backflow form to each affected customer when it is time for the annual test of their backflow prevention assembly. A water shut-off notice will be issued to customers who fail to arrange for testing of their backflow prevention assembly by a specified due date. If the customer is non-responsive within the allotted time, LACWD may terminate water service to the property until the assembly is tested and the completed form is submitted.
For more information please contact Tiffany Lai at (626) 300-4689
Approved Backflow Prevention Assemblies
LACWD accepts backflow prevention assemblies approved by the USC Foundation for Cross-Connection Control and Hydraulic Research. Backflow prevention assemblies for domestic lines must also meet the "lead free" requirements per Health and Safety Code (HSC) section 116875.
List of approved backflow prevention assemblies: http://fccchr.usc.edu/list.html
Certified Backflow Prevention Assembly Testers
LACWD accepts test, repair, and installation of backflow prevention assemblies performed by a backflow tester certified by the County of Los Angeles Department of Public Health.
List of employers of certified testers: http://www.publichealth.lacounty.gov/eh/docs/ep_cross_con_emplist.pdf
List of certified testers: http://publichealth.lacounty.gov/eh/docs/ep_cross_con_testerlist.pdf
County of Los Angeles Department of Public Health
LACWD does not monitor on-site backflow prevention assemblies that protect the internal plumbing system within the property. LACWD does not administer backflow tester certification. For annual testing of on-site backflow prevention assemblies or backflow tester certification, please contact the County of Los Angeles Department of Public Health's Cross Connection and Water Pollution Control Program at:
Phone: (626) 430-5290