Sonoma County, CA · PWSID CA4910020
Sonoma County Water Agency lead service lines
15 lead or galvanized lines to replace
Sonoma County Water Agency reported 0 lead and 15 galvanized-requiring-replacement service lines out of 179 in its inventory. That's about 1 in 12 lines. Another 0 (0%) are still listed as unknown material.
Ranks #48 of 92 California systems with confirmed lead lines, and #4,124 nationally.
8.4% of Sonoma County Water Agency's service lines are lead or galvanized requiring replacement. That's higher than the California average (0.1%) and higher than the national average (3.1%).
- Lead 0%
- Galvanized (replace) 8.4%
- Unknown 0%
- Non-lead 92%
Total service lines reported: 179. Reported all required service line types. Population served: 0; 162 connections.
Progress since 2025 Q1
Reported lead and galvanized-requiring-replacement lines went from 15 in 2025 Q1 to 15 in 2026 Q3: no change. Lines of unknown material went from 0 to 0, no change.
Quarterly counts reported to EPA. A drop usually means lines were replaced or confirmed non-lead; a rise usually means more lines were identified. Replacement progress rankings.
Lead rule violations
EPA's data lists no Lead and Copper Rule violations for Sonoma County Water Agency since 2015. That covers testing, reporting, corrosion control and public notice requirements; it isn't a guarantee about any individual home.
Source: EPA SDWIS violation records for the Lead and Copper Rule.
Where the water comes from
Sonoma County Water Agency's main water source is groundwater (wells). It sells water to 14 other water systems: Marin Municipal Water District, North Marin Water District, Lawndale Mutual Water Company, Penngrove Water Company (Puc), City of Petaluma, City of Santa Rosa, City of Sonoma, Valley of the Moon Water District, City of Rohnert Park, City of Cotati, Town of Windsor, Forestville Water District, California-American Larkfield (Puc), Kenwood Village Water Company (Puc).
Source: EPA SDWIS water system and facility records.
Check your own address
These counts cover the whole system. To see whether your line is lead, use the utility's address-level inventory. Utilities had to prepare one by October 16, 2024 and make it publicly accessible; systems serving more than 50,000 people must post it online.
No map yet? Do the 2-minute scratch and magnet test on the pipe where water enters your home.
Protect your drinking water now
If your line is lead, galvanized or unknown, filter water for drinking, cooking and baby formula. Use a filter certified to NSF/ANSI 53 for lead. Run cold water for a few minutes after it sits for hours, and never use hot tap water for cooking.
How to pick a lead-certified filter · How to test your water for lead
Getting the line replaced
EPA's Lead and Copper Rule Improvements require most systems to replace lead and galvanized-requiring-replacement lines by December 31, 2037. Ask Sonoma County Water Agency whether it replaces the private side for free or with a cost share before you hire anyone. If you want it done sooner, or your utility doesn't cover your side, a licensed plumber can quote it. What replacement costs.
County pages: Lead pipes in Sonoma County
Other water systems nearby
| System | Lead + galv. | Unknown |
|---|---|---|
| City of Petaluma | 122 | 4,588 |
| City of Sonoma | 483 | 432 |
| Willowside Mutual Water Company | 2 | 158 |
| Stonegate Mobile Home Park | 3 | 0 |
| Kelly Mutual Water Company | 1 | 37 |
| South Cloverdale Water Company | 36 | 0 |
| Blue Spruce Mobile Home Park | 3 | 0 |
| Lichau Hylands Mutual Water Company | 3 | 15 |
Check another water system
Questions
Does Sonoma County Water Agency have lead pipes?
Yes. Sonoma County Water Agency reported 0 lead service lines and 15 galvanized lines that must be replaced, out of 179 total. 0 more are of unknown material.
How do I check if my home's service line is lead?
Look up your address on Sonoma County Water Agency's official service line inventory, which utilities must make publicly available. You can also scratch the pipe where it enters your home: lead is soft, dull gray, scratches to shiny silver and does not attract a magnet.
When will Sonoma County Water Agency replace lead service lines?
Under EPA's Lead and Copper Rule Improvements, most systems must replace lead and galvanized-requiring-replacement lines by December 31, 2037, starting from November 1, 2027. The rule is being challenged in court, so dates could change. Many utilities run free or cost-share programs now.
Has Sonoma County Water Agency had lead violations?
EPA's data shows no Lead and Copper Rule violations since 2015 for Sonoma County Water Agency.
Which water filters remove lead?
Use a filter certified to NSF/ANSI Standard 53 for lead reduction, or NSF/ANSI 58 for reverse osmosis. Check the certification on NSF's listings, not just the box.
Embed or cite this data
Local news sites, blogs and community groups can embed this card. It updates when EPA releases new data.
Citation: Lead Pipe Map, "Sonoma County Water Agency lead service lines," https://leadpipemap.com/ca/sonoma-county-water-agency/. Source: EPA SDWIS service line inventory, 2026 Q3. Download the full dataset on the data page.