Contra Costa County, CA Building Safety: Plumbing Permits (2026)

Unincorporated Contra Costa County enforces the 2022 California Plumbing Code (CPC) with local amendments adopted in Ordinance Code Title 7, Division 72. A plumbing permit is required for installing, altering, replacing, or repairing any plumbing system, including water heaters, water softeners, gas lines, sewer laterals, backflow prevention devices, and fixtures beyond simple like-for-like faucet or valve replacements. Water heater replacements require seismic strapping, proper venting (especially for gas units), expansion tank where applicable, and a drip pan with drain when installed in locations where leaks could cause damage. Sewer lateral replacements in the Central Contra Costa Sanitary District (CCCSD), West County Wastewater District, and Mt. View Sanitary District service areas are subject to additional district requirements, including testing and compliance certificates at property transfer under local sewer lateral ordinances. Backflow prevention testing is required annually for irrigation systems connected to potable water. All work must be performed by a CSLB-licensed C-36 plumbing contractor unless the homeowner qualifies for owner-builder status. Inspections are scheduled through the County's online portal.