Ventura County, CA
Septic (OWTS) permits in Ventura County
Updated · Prepared by the Plumb Right Now editorial team
Short answer
Ventura County's Environmental Health Division requires an OWTS construction permit for any new septic system and for repairs, meaning replacing an old tank or disposal field with a new one. Design follows the county's Local Agency Management Program, approved in 2018, and its OWTS technical manual. The division also certifies private well water quality and regulates small water systems.
What Ventura County handles
OWTS construction permits are required for any new system and for repairs, where repair means abandoning an old tank or disposal field and installing a new one in its place. [1]
The Ventura County Local Agency Management Program (LAMP) for onsite wastewater treatment systems was approved by the Board of Supervisors on August 7, 2018. [2]
The Environmental Health Division certifies the water quality of private wells, regulates small water systems and permits septic systems. [1]
Where septic is common
Septic systems are common in rural canyons, hillside parcels and agricultural areas. Most homes in Oxnard, Simi Valley and Thousand Oaks are on city sewer, so their plumbing permits come from the city.
Planning a septic repair
- Pump and inspect the tank to find whether the tank, lines or disposal field failed; a sewer smell in the house or soggy ground over the field are typical signs.
- Get the OWTS construction permit before replacing a tank or field; like-for-like replacement still counts as a repair.
- If the property also has a private well, ask about well water certification when you sell or refinance.
- For drain and sewer problems inside the house, see drain cleaning.
Common questions
Do I need a permit to replace a septic tank in Ventura County?
Yes. Replacing a tank or disposal field counts as a repair and needs an OWTS construction permit.
What is Ventura County's septic LAMP?
The Local Agency Management Program, approved August 7, 2018, that sets local septic standards under state policy.
Who permits septic systems in Ventura County?
The Environmental Health Division of the Resource Management Agency.
Does Ventura County test private wells?
The Environmental Health Division certifies private well water quality and regulates small water systems.
Is there a septic design manual for Ventura County?
Yes, the OWTS Technical Manual guides owners, designers and installers.
Are Oxnard and Thousand Oaks homes on septic?
Most are on city sewer; county septic rules apply mainly to rural and hillside parcels.
Is pumping a septic tank a repair in Ventura County?
No. Routine pumping isn't a repair; replacing a tank or field is.
Do new septic systems in Ventura County need a construction permit?
Yes, every new system needs an OWTS construction permit.
When did Ventura County update its septic rules?
After the state's 2012 OWTS policy, the county adopted its LAMP in 2018.
Who should I call about a failing septic system in Ventura County?
A septic contractor to diagnose it, then Environmental Health for the repair permit.
Cities and services in Ventura County
- Plumbing services in OxnardOxnard is a coastal farming and port city with post-war neighborhoods near downtown and newer tracts toward the beach. The city blends imported State …
- Plumbing services in Simi ValleySimi Valley is a mostly owner-occupied suburb of 1960s–80s tract homes in a valley north of Los Angeles. Most of its water is State Water Project wate…
- Plumbing services in Thousand OaksThousand Oaks is a mostly owner-occupied Conejo Valley suburb of 1960s–80s homes among oak-covered hills. Its city water is nearly all imported State …
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- Backflow Testing in CaliforniaCalifornia backflow testing under the State Water Board's cross-connection handbook: in effect since July 2024, annual tests, and what homes need.
- Plumbing in CaliforniaStatewide code, licensing and climate for California.
Other California counties
- Sewer laterals in the San Diego County Sanitation DistrictSewer laterals in county sanitation district areas: owners must try to clear stoppages first, when the district helps past the property line, and owner liability.
- Septic (OWTS) permits in Riverside CountyRiverside County permits septic systems in unincorporated areas and contract cities: when an OWTS application is needed and who can do perc tests.
- Septic (OWTS) permits in San Bernardino CountySan Bernardino County septic rules: when sewer connection is required, perc reports, the half-acre minimum lot, and operating permits for holding tanks.