Solano County, CA Building Safety: Plumbing Permits (2026)
Key Facts
- Adopted plumbing code
- California Plumbing Code, 2025 Edition
- Minimum well yield
- 3 gallons/minute at 10 psi for 4 hours
- Low-yield exception cutoff
- Parcels created before Sept. 28, 1993
- Well testing validity
- Verified within 2 years of permit application
- Final inspection condition
- Dwelling must be connected to approved supply
Summary
Solano County will not issue a grading, building, or plumbing permit for any project needing new potable water service until the applicant proves the water source is adequate under Code Sec. 6.3-52. That means a letter from a public water purveyor, a connection permit, or a tested and certified on-site well, spring, or surface supply.
No grading, building or plumbing permit application or plans for a project which will require new service with potable water shall be issued unless: (1) The building official is provided a written statement from the operator of an approved public water agency that the purveyor will provide potable water service to the dwelling and that the water purveyor has sufficient water resource and system capacity to provide such service; or (2) The building official is provided evidence that a permit or other authorization has been granted by the water purveyor for the proposed project to connect to and use the domestic water system; or (3) An on-site well, spring or surface supply is installed, tested and is certified to satisfy the requirement of Section 6.3-51(b)... (b) No final building inspection for a dwelling shall be approved until the dwelling is connected to an operating water supply approved pursuant to this section.
Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through Ordinance 1868, passed April 9, 2026).
Full Breakdown
Sec. 3-03(a)(6) adopts the 2025 California Plumbing Code as part of the county's building code family. On top of that adoption, Sec. 3-52 imposes a hard local gate on plumbing permits: "No grading, building or plumbing permit application or plans for a project which will require new service with potable water shall be issued unless" the Building Official receives a written statement from an approved public water agency confirming it will serve the dwelling and has sufficient capacity, or evidence a water purveyor has authorized connection to its system, or evidence that an on-site well, spring, or surface supply has been installed, tested, and certified to meet Sec.
3-51(b) standards. coli if an initial sample tests positive. Sec. 3-51 fills in the substantive well standards behind that gate: an on-site well must deliver a minimum of 3 gallons per minute for four hours at 10 psi to qualify outright, wells producing 3 to 5 gallons per minute need at least 500 gallons of storage under Sec. 26-80(e), and wells below 3 gallons per minute are rejected except for parcels legally created before September 28, 1993, which need at least 1 gallon per minute combined with storage to reach 5 gallons per minute at 10 psi.
Well or spring capacity must be verified within two years of the building permit application (Sec. 3-51(e)). Sec. 3-52(b) closes the loop at the back end: "No final building inspection for a dwelling shall be approved until the dwelling is connected to an operating water supply approved pursuant to this section," so a project cannot obtain a certificate of occupancy on an unverified water source even if it cleared the initial permit stage.
Violations & Fines
Applying for or performing plumbing work in violation of Sec. 6.3-52's water-verification requirement, or without a required plumbing permit generally, is an infraction under Sec. 6.3-09(a) and (e), with each additional day of noncompliance after citation counted as a further violation. Sec. 6.3-09(f) adds liability for the county's costs of correction, abatement, and prosecution beyond the infraction fine, and Sec. 6.3-09(d) authorizes the Building Official and deputies to issue citations directly.
Frequently Asked Questions
Can I get a Solano County plumbing permit if my home relies on well water?
What documentation does the county need for a public water connection?
Does well water need to be tested for bacteria before a permit issues?
Can I get a final inspection before my water supply is hooked up?
Sources & Official References
Other rules in Solano County
California rules heatmap·Compare Solano County to another location·View the California building safety overview
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