What is a sewer backwater valve?
The majority of properties in Torrance have been built so that a blockage in the public sewer will not cause a sewage backup into the property. However, some properties require the protection of a backwater valve in the owner's drain line. These properties have been built (see picture) so that the flood rim of the lowest plumbing fixture (bath tub, shower, etc.,) is lower than the cover of the nearest upstream manhole of the public sewer. The backwater valve is designed to automatically close, to prevent sewage from backing up into the building from a blocked public sewer.
What should I check for?
1. If you have any plumbing fixtures lower than the street in front of your house, you may need a backwater valve. 2. If the street outside your house goes steeply uphill, you may need a backwater valve. 3. If your property already has a backwater valve, it needs to be checked and maintained regularly.
Who is responsible for the installation and maintenance of backwater valves?
Property owners are responsible for the installation and maintenance of backwater valves.
How often do I check the backwater valve and what does it entail?
We recommend that you check and maintain the valve at least once a year. If you have a history of sewer blockages, you should check more often. Checking the newer installations involves a quick removal of the device to check that the valve flap is functioning. The entire mechanism and surrounding pipe should be flushed with a hose during maintenance to clear any accumulated debris from the area. Older installations are cast iron and more difficult to maintain. For any maintenance questions or issues, please call a plumber.
Can the backwater valve be used as a cleanout?
No! Anytime a sewer snake passes through a backwater valve damage can occur to the valve flapper or the finished seating surface against which the flapper seals.
Where can I get help?
If you think you might need a backwater valve or if you have questions regarding locating or checking the device, the City of Torrance encourages you to contact a licensed plumber. The licensed plumber can evaluate your situation and, if necessary, install a backwater valve.
Where can I get a backwater valve?
Backwater valves are sold through plumbing supply warehouses and sometimes home improvement centers. Contractors should contact their local wholesale plumbing supplier or water and sewer wholesale supplier to purchase the valve.
Do I need a Permit for a backwater valve?
Yes, a City plumbing permit is required for the installation of a backwater valve. For further information see Building Permits, or call the City's Permit Section at (310) 618-5910.