Sourced from the State Water Resources Control Board OWTS Policy Regional Jurisdictions and Contact list, and Attachment 3 Table 7 of the OWTS Policy — last checked August 2026.
California Septic Guide — Reference
Who Issues Your Septic Permit in California?
There is no single statewide permit desk. The State Water Board writes the OWTS Policy, but permits come from your county environmental health department, overseen by one of nine Regional Water Quality Control Boards. Here is the full jurisdiction map.
Region 1 — North Coast
Del Norte County · Humboldt County · Mendocino County · Siskiyou County · Sonoma County · Trinity County
Region 2 — San Francisco Bay
Marin County · Alameda County · San Mateo County
Region 3 — Central Coast
Santa Barbara County · Monterey County · San Luis Obispo County · City of Atascadero · San Benito County · Santa Cruz County · Santa Clara County
Region 4 — Los Angeles
Ventura County · Los Angeles County
Region 5 — Central Valley
Butte County · Glenn County · Modoc County · Plumas County · Shasta County · Tehama County · Town of Paradise · Amador County · Colusa County · El Dorado County · Lake County · Nevada County · Placer County · Sacramento County · San Joaquin County · Sierra County · Solano County · Stanislaus County · Sutter County · Yolo County · Yuba County · Calaveras County · Fresno County · Kern County · Kings County · Madera County · Mariposa County · Merced County · Tulare County · Tuolumne County
Region 6 — Lahontan
Alpine County · Lassen County · City of Adelanto · Town of Apple Valley · City of Barstow · California City · City of Hesperia · Inyo County · Mono County · San Bernardino County
Region 7 — Colorado River Basin
Imperial County · Riverside County (unincorporated) · City of Needles
Region 8 — Santa Ana
Orange County (unincorporated) · City of Yucaipa · City of Rancho Cucamonga · City of Redlands
Region 9 — San Diego
County of San Diego
Riverside and Orange are listed as unincorporated only. If your property sits inside city limits in either county, your permitting path may differ from what county-level guidance tells you.
Eleven cities run their own programs. Atascadero, Paradise, Adelanto, Apple Valley, Barstow, California City, Hesperia, Needles, Yucaipa, Rancho Cucamonga and Redlands are each listed separately from their surrounding county, so county guidance may not apply.
Jurisdiction list from the State Water Board’s OWTS Policy Regional Jurisdictions and Contact list, which cites Attachment 3, Table 7 of the Policy as authoritative. Programs change; confirm with your local agency. General questions: DWQ-WDR@Waterboards.ca.gov
The Three Layers
The State Water Resources Control Board writes the OWTS Policy. It doesn’t issue residential permits.
Nine Regional Water Quality Control Boards oversee local agencies, approve Local Agency Management Programs, and step in as the permitting authority where a proposal falls outside the local program.
Roughly 66 local agencies — mostly county environmental health departments, plus eleven cities — issue permits and inspect installations. This is where you actually apply.
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When the Regional Board Becomes Your Permitting Authority
Most of the time you deal with your county. The Regional Water Board takes over when a proposal sits outside what the local program can approve.
The Central Coast Water Board publishes a clear worked example. A permit must come from the Water Board rather than the county where:
• The system does not meet Tier 1 requirements, or
• It’s in Santa Barbara or Monterey County and doesn’t meet their approved LAMP or Tier 1, or
• Projected flow exceeds 3,500 gallons per day and the property is outside Santa Barbara or Monterey jurisdiction
That third condition is worth noting. 3,500 gpd is the Tier 1 ceiling — so in a county without a LAMP, exceeding it means the county can’t permit your system under Tier 1 and the Regional Board becomes involved.
The Two Traps
2. Eleven cities run their own programs. Atascadero, Paradise, Adelanto, Apple Valley, Barstow, California City, Hesperia, Needles, Yucaipa, Rancho Cucamonga and Redlands are each listed separately from their surrounding county. County guidance may not apply to you.
Region 5 Is Almost Half the State
Worth knowing if you’re anywhere in the Central Valley or Sierra foothills.
The Central Valley Regional Water Board (Region 5) oversees roughly 30 local agencies — nearly half of California’s total. Butte, Shasta, Tehama, El Dorado, Placer, Nevada, Sacramento, San Joaquin, Fresno, Kern, Tulare and about twenty more.
Practical consequence: requirements vary more within Region 5 than in any other part of California. Regional generalizations are less reliable here than anywhere else, and confirming your specific county matters more.
Large Systems and High-Strength Waste
Separate from the tier framework, owners of systems with projected flow over 10,000 gpd, or that receive high-strength wastewater, must notify the Regional Water Board. Those systems may be required to submit a Report of Waste Discharge for coverage under Waste Discharge Requirements, or a Waiver of WDR.
Restaurants, wineries and tasting rooms often fall into the high-strength category. See our commercial food service guide.
Where to Start
Your county environmental health department is almost always the right first call. They issue the permit, they know whether the county has a LAMP, and they know whether an APMP covers your area.
For general questions the State Water Board can be reached at DWQ-WDR@Waterboards.ca.gov.
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Frequently Asked Questions
Who issues septic permits in California?
Your county environmental health department in most cases. The State Water Board writes the OWTS Policy, nine Regional Water Quality Control Boards oversee implementation, and roughly 66 local agencies issue the actual permits.
When does the Regional Water Board issue the permit instead?
Where a proposal falls outside what the local program can approve. The Central Coast example: a system that does not meet Tier 1, or one in Santa Barbara or Monterey County that does not meet their LAMP, or projected flow over 3,500 gpd outside those counties.
Why does it matter that Riverside and Orange are listed as unincorporated?
Because the state jurisdiction list names only the unincorporated portions. If your property is inside city limits in either county, your permitting path may differ from county-level guidance.
Which region covers the most counties?
Region 5, the Central Valley Water Board, oversees roughly 30 local agencies — nearly half of California total. Requirements vary more within Region 5 than anywhere else in the state.