The sewer system, also known as the collections system, includes 2,800 miles of sewer pipe, most of it only eight inches wide. With small pipes like these, DWR employees use a few innovative ways to inspect them and make repairs.
Smoke testing
Smoke testing helps locate faulty pipes, which can allow stormwater or ground water to enter the sanitary sewer system. It also finds illegal connections to the sewer system, like storm drains or roof drains. Stormwater connections to the sewer system cause an unnecessary load on wastewater treatment plants and could potentially cause sanitary sewer backups.
During the test, a non-toxic smoke is forced into the sewer lines in your neighborhood. This smoke leaves no residuals or stains and has no harmful effects on plants or animals. If the smoke is seen coming out of a structure that should not be connected, then the connection can be addressed. Neighborhoods are notified by door hangers at least 24 hours prior to testing.
CCTV
DWR employees use remote control video cameras and other detection tools to assess the condition of our buried pipes to determine when repair, rehabilitation, or replacement is required.
A camera tethered to a cable is lowered into a manhole. Using a large monitor and controls inside of a work truck, the camera can be steered through the sewer system. These cameras can record video footage, take pictures, and even use a zoom lens to look up into sewer laterals. Our specially-trained crews can then use these videos and pictures to determine the condition of the sewer main and its connections. Check out the video at the bottom of this page to see what it’s like to use one of these cameras in the sewer system.
Hydro-jetting
Hydro-jetting is a key part of the sewer maintenance program to keep wastewater flowing through the public sewer system. A jetting unit is mounted on a specialized truck and propels a high-pressure nozzle through the pipes to clear debris, grease, and buildup from the inside of sewer pipes. This helps prevent backups that can lead to overflows.
For most residents, jetting is non-invasive and goes unnoticed. However, on rare occasions, cleaning can possibly affect household plumbing. You might hear noise from sinks, notice toilets gurgling, or in very rare cases, water may splash from toilet bowls. Keep toilet lids closed while work is underway. Odors can also be emitted if water is drawn out of p-traps. If this happens, simply run water in sinks, tubs, and showers to refill the traps. When possible, signs will be placed at neighborhood entrances to notify residents when maintenance is scheduled or occurring nearby.