San Diego County, California septic permits and requirements

Permitting authority

County of San Diego Department of Environmental Health and Quality (DEHQ) — Land and Water Quality / Onsite Wastewater Treatment Systems

DEHQ Land and Water Quality duty desk: 858-565-5173; septic inspection line: 858-694-2553. Permit counter: 5500 Overland Avenue, Suite 110, San Diego, CA 92123.

California OWTS framework

California uses a statewide risk-based OWTS policy while recognizing local permitting agencies and Regional Water Boards. Counties with approved Local Agency Management Programs can implement locally tailored siting and design standards, so the county procedure and current LAMP should be checked for the parcel.

County DEHQ regulates septic systems countywide

San Diego County DEHQ regulates the installation and modification of onsite wastewater treatment systems, including systems in incorporated cities. The county program provides design review for new systems and repairs/modifications, installation inspections, records, complaint response, and development-project review.

Current local standards are in the 2025 LAMP

San Diego County implements a Local Agency Management Program (LAMP) with local siting and design standards. The county identifies its current 2025 LAMP as effective February 1, 2025, along with updated application forms for percolation testing, installation permits, repair authorization, professional registration, and related OWTS work.

Percolation, design, and system sizing

For residential systems, the county states that disposal-field sizing uses percolation-test results together with the number of bedrooms; septic-tank sizing is also based on bedrooms. Licensed civil engineers, registered geologists, and registered environmental health specialists are recognized by the county as qualified septic-system designers.

Installation and contractor requirements

A property owner may obtain a permit to install a septic system on the owner’s own property. In other situations, San Diego County states that a licensed C-36, C-42, Class A, or Class B contractor is required to obtain permits to install the system.

Repairs and modifications are reviewed and inspected

DEHQ publishes a Septic Repair Authorization Application and lists design review of repairs and modifications plus installation inspections among its program services. Owners should obtain county authorization before repair or modification work and keep the work accessible for required inspection.

Supplemental treatment systems have additional obligations

Supplemental treatment systems require percolation testing and design by a licensed OWTS professional. San Diego County also administers an annual operating-permit program for supplemental treatment systems, so owners should verify the current operation, maintenance, and monitoring requirements for the approved system type.

Current fees and online services

DEHQ adopted FY 2026-27 fees effective July 11, 2026. Because charges depend on the service and can be reassessed when work crosses fiscal years, SepticScope links the current county fee page rather than freezing a fee amount. County Citizen Access supports permit applications, record searches, fee payments, and inspection-related services.

Official sources

SepticScope summarizes public-agency information for planning purposes. The permitting agency's current instructions control if they differ from this guide.

Report outdated county information

Septic rules, forms and agency pages can change. If you find a broken official link or a county requirement that has changed, send SepticScope feedback and include the current local government source.