Septic Systems and Private Sewers

Sewage from private homes must be treated to destroy disease-carrying germs and protect ground water quality. Most sewage from private property is conveyed through pipes from structures to public sanitary sewers.

Properly installed and operating backwater valves are also an important part of the private sewer system.

In some parts of the City, public sewers are not available nearby for connection or homes were built before public sewers were available. In these cases, sewage is treated by On-site Wastewater Treatment Systems (OWTS), also called septic systems. Since septic systems are on private property, property owners have complete responsibility for taking care of them.

The City manages a number of programs that can help homeowners and businesses avoid common problems with their private sewers and septic systems. Please click on the links on the left to learn how you can save time and money on repairs and protect the health of your neighborhood.


The City’s OWTS Group serves as the responsible local agency for the 13,000 OWTS within the City, and remains in constant contact with federal, state and other local government entities to ensure that OWTS are meeting water quality and construction standards for maintaining the City’s environmental and public health needs

LA Sanitation’s OWTS Group provides information on how OWTS should properly function and tips for proper operation and maintenance through a homeowner guide that is readily available online. By doing this, the OWTS Group hopes to help prolong the life of OWTS owned by homeowners and operators and avoid the common issues of spills and overflows caused by substandard conditions or failing OWTS.

LA Sanitation’s OWTS Group continues to proactively explore several funding sources to assist OWTS owners who would like to properly abandon their OWTS and connect to the sewer. So far a total of $13.5 million in grant funding applications have been submitted to the following programs:
  • Cleanup & Abatement Account ($10,000,000)
  • Community Development Block Grant ($1,893,421) 
  • Integrated Regional Water Management Program ($1,339, 486) 
  • Clean Water Act 319(h) Non-point Source Grant ($218,750)

If secured, these funds would be used to construct public sewers within unsewered areas of the City, especially those designated as high-risk areas and disadvantaged communities.

Additionally, LA Sanitation’s OWTS Group is partnering with the EPA, the Department of City Planning and the Green Streets Committee to phase out high-risk large capacity cesspools that pose the greatest threat to the City’s water resources.


LA Sanitation’s OWTS Group is assisting the Bureau of Engineering (BOE) in developing Sewer Assessment Projects that would provide sewers within areas of the City that are unsewered. An Assessment Proceeding is a democratic way by which a majority of OWTS Owners within an area can get together to build sewers for OWTS connection and pay a fair share over a period of time.


LA Sanitation’s OWTS Group collaborates with the Bureau of Engineering, LA Sanitation’s Watershed Protection Division, Department of Building and Safety and the Regional Water Quality Control Board to assist OWTS owners and operators to permit the new construction, alteration, or replacement of OWTS.