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CA State Water Resources Control Board - Septic System Policy
CA Regional Water Quality Control Board - San Diego Region 9
CA Regional Water Quality Control Board - Colorado River Region 7
CA State Water Resources Control Board
EPA Septic Systems Page

Septic Systems

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The purpose of regulating the design, installation, and maintenance of septic systems (onsite wastewater treatment systems) is to prevent public health nuisance conditions caused by failing onsite wastewater treatment systems.  The program's goals are:

  • Ensure that these systems can operate in all weather conditions with minimal maintenance
  • Prevent the contamination of groundwater from improperly designed onsite wastewater treatment systems
  • Prevent the contamination of surface water from improperly designed onsite wastewater treatment systems
  • Prevent premature failure of onsite wastewater treatment systems

Program Services | Contact Us| Useful Information | Types of Systems 

Update on Assembly Bill 885

On June 19, 2012, the State Water Resources Control Board (SWRCB) adopted Resolution No. 2012-0032, adopting the Water Quality Control Policy for Siting, Design, Operation and Maintenance of Onsite Wastewater Treatment Systems (OWTS Policy) and approving the supporting substitute environmental documentation. The administrative record for the OWTS Policy was approved by the Office of Administrative Law (OAL) on November 13, 2012 and the OWTS Policy will become effective on May 13, 2013.    

The Regional Water Quality Control Board (RWQCB) is required to incorporate the standards established in the OWTS Policy, or standards that are more protective of the environment and public health, into their water quality control plans within 12 months of the effective date of the OWTS Policy. Implementation of the OWTS Policy will be overseen by the SWRCB and the RWQCB, and DEH will have the opportunity to implement a Local Agency Management Program (LAMP) if approved by RWQCB.

DEH is currently developing a LAMP for review and approval by the RWQCB to allow for the implementation of the OWTS Policy in San Diego County.  The LAMP will include siting, design, operation and maintenance requirements for both conventional and alternative OWTS.  In addition, DEH is working to modify our local ordinance to allow for the use of alternative OWTS for new construction.

Please select the link below to view the OWTS Policy and associated State documents.

OWTS Policy

Program Services

  • Design review of new onsite wastewater treatment systems and Graywater Systems
  • Design review of repairs and modifications to existing on-site wastewater treatment systems
  • Installation inspections of onsite wastewater treatment systems
  • Maintain design records for properties using onsite wastewater treatment systems
  • Respond to citizen complaints of failing onsite wastewater treatment systems
  • Provide coordinated review with other agencies for projects that require CEQA (California Environmental Quality Act) and involve the use of onsite wastewater treatment systems

Types of Systems

Currently DEH is approving only conventional system designs that consist of a septic tank going to either leach lines or seepage pits.

  • Septic tanks must have IAPMO approval and be approved for use by DEH.
  • Leach lines can be constructed with either rock and pipe or other approved materials that would include plastic chambers
  • Horizontal seepage pits are restricted to sites with uniform soil conditions and average percolation rates not exceeding 30 minutes per inch.  
  • Vertical seepage pits are restricted to coastal sedimentary basins that have degraded groundwater caused by salt water intrusion.
  • Mound systems are allowed in the areas within the former Valley Center Moratorium area, and the South Citrus Avenue basin area where engineering demonstrates the site conditions are suitable.
  • Advanced treatment systems are currently considered experimental systems and are restricted to repairs where a conventional repair is not feasible.

Useful Information


Frequently Asked Questions

Design Manual for Onsite Wastewater Treatment Systems

Guidelines/Septic System Design Criteria

Groundwater Separation Requirements

Percolation Test Form

Reservoir Setback Requirements

San Diego County Code: Onsite Wastewater System Ordinance

EPA Homeowner's Guide to Septic Systems - (Spanish- Guía del dueño de hogar
para sistemas sépticos