County · California
Sonoma County, California: drinking water records
Explore EPA records for 130 community water systems across 38 ZIP codes in Sonoma County, then find water-testing resources and available recent monitoring-station readings.
Data as of EPA UCMR 5 final release, August 2026 (file dated Aug 28, 2026) · EPA SDWIS 2026Q2 (file dated Jul 9, 2026). How we build these pages
Drinking-water records
EPA survey and compliance records are historical reports. UCMR 5 results are available for 16 of the 130 listed systems in this snapshot. A system with no reported PFAS detection is not a test of every tap or every contaminant.
System population figures are summed from EPA registry records and can overlap where wholesalers and retail systems serve the same people. They are not a Census county-population estimate.
Water systems in this county
All 130 active community systems in the available county records, sorted by record completeness. Scroll the table to explore more systems.
| Water system | People served | PFAS survey results | PFAS found | Health-based violations | Lead, 9 in 10 homes at or below |
|---|---|---|---|---|---|
| Sonoma State University CA4910027 | 10,986 | 56 | 0 | 1 | 0 ppbbelow the action level |
| Sea Ranch Water Company,the (Puc) CA4910007 | 1,160 | 180 | 1 | 1 | 0 ppbbelow the action level |
| Santa Rosa, City of CA4910009 | 175,396 | 120 | 0 | 0 | 1.3 ppbbelow the action level |
| Petaluma, City of CA4910006 | 60,781 | 60 | 0 | 0 | 0 ppbbelow the action level |
| Rohnert Park, City of CA4910014 | 43,821 | 480 | 3 | 0 | 0 ppbbelow the action level |
| Windsor, Town of CA4910017 | 25,561 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Valley of the Moon Water District CA4910013 | 23,107 | 415 | 6 | 0 | 0 ppbbelow the action level |
| Sonoma, City of CA4910012 | 11,725 | 360 | 2 | 0 | 0 ppbbelow the action level |
| Healdsburg, City of CA4910005 | 10,985 | 300 | 3 | 0 | 0 ppbbelow the action level |
| Cloverdale, City of CA4910002 | 10,398 | 120 | 0 | 0 | 0 ppbbelow the action level |
| California-American Larkfield (Puc) CA4910023 | 7,913 | 120 | 0 | 0 | 6 ppbbelow the action level |
| Sebastopol, City of CA4910011 | 7,522 | 240 | 0 | 0 | 0 ppbbelow the action level |
| Cotati, City of CA4910016 | 7,303 | 300 | 0 | 0 | 0 ppbbelow the action level |
| Sweetwater Springs Cwd - Guerneville CA4910004 | 6,000 | 60 | 0 | 0 | 0 ppbbelow the action level |
| Russian River County Water District CA4910008 | 4,150 | 60 | 0 | 0 | 0 ppbbelow the action level |
| California-American Geyserville (Puc) CA4910024 | 1,046 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Diamond a Mutual Water Company CA4900562 | 640 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Cazadero Water Company, INC. (Puc) CA4900508 | 525 | 0 | 0 | 6 | 0 ppbbelow the action level |
| U.S. Coast Guard Training Center CA4910701 | 469 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Rincon Valley Mobile Estates CA4900600 | 460 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Sonoma County Csa 41-Jenner CA4900532 | 406 | 0 | 0 | 11 | 2.7 ppbbelow the action level |
| Branger Mutual Water Company, INC. CA4900545 | 300 | 0 | 0 | 2 | 3.3 ppbbelow the action level |
| Timber Cove County Water District CA4900584 | 271 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Magic Mountain Mutual Water Company CA4900637 | 221 | 0 | 0 | 1 | 6 ppbbelow the action level |
| Mobile Home Estates CA4900720 | 210 | 0 | 0 | 1 | 0 ppbbelow the action level |
| James Court Water System CA4901445 | 208 | 0 | 0 | 1 | 0 ppbbelow the action level |
| El Portal Mobile Estates CA4900799 | 200 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Randal'S Ranchette Mutual Water Company CA4900599 | 200 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Western Mobile Home Park CA4900791 | 178 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Plaza Mobile Home Park CA4900787 | 169 | 0 | 0 | 1 | 3.5 ppbbelow the action level |
| Sonoma Ranch Mutual Water Company CA4900843 | 151 | 0 | 0 | 1 | 0 ppbbelow the action level |
| George Ranch Mutual Water Company CA4900973 | 148 | 0 | 0 | 1 | 2.7 ppbbelow the action level |
| Sunset Park Community CA4900794 | 141 | 0 | 0 | 1 | 3.5 ppbbelow the action level |
| Kelly Mutual Water Company CA4900560 | 135 | 0 | 0 | 1 | 3.4 ppbbelow the action level |
| South Cloverdale Water Company CA4900510 | 90 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Valley Ford Water Association CA4900568 | 88 | 0 | 0 | 48 | 9 ppbbelow the action level |
| Bodega Water Company CA4900850 | 77 | 0 | 0 | 1 | 1.8 ppbbelow the action level |
| Park Royal Mutual Water Company CA4900553 | 75 | 0 | 0 | 2 | 0 ppbbelow the action level |
| Bridgehaven Park CA4900644 | 70 | 0 | 0 | 5 | 0 ppbbelow the action level |
| Robin Way Water System CA4900913 | 66 | 0 | 0 | 5 | 3.4 ppbbelow the action level |
| Six Acres Water Company CA4900608 | 66 | 0 | 0 | 7 | 3.4 ppbbelow the action level |
| Delores Lane Water System CA4901346 | 59 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Sonoma County Mutual Water Company CA4900640 | 40 | 0 | 0 | 36 | 2.8 ppbbelow the action level |
| Loch Haven Mutual Water Company CA4900575 | 26 | 0 | 0 | 5 | 0 ppbbelow the action level |
| Mark West Meadows Mutual Water CA4900905 | 20 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Forestville Water District CA4910019 | 3,788 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Sweetwater Springs Cwd - Monte Rio CA4910028 | 3,000 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Penngrove Water Company (Puc) CA4910003 | 1,742 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Sonoma County Csa 41-Fitch Mountain CA4910010 | 1,265 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Camp Meeker Water System CA4910029 | 1,171 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Bodega Bay Public Utility District CA4910021 | 1,069 | 0 | 0 | 0 | 1.9 ppbbelow the action level |
| Kenwood Village Water Company (Puc) CA4910025 | 1,029 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Canon Manor Water System CA4910022 | 805 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Odd Fellows Recreation Club CA4910026 | 757 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Moon Valley Water System CA4900871 | 691 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Occidental Community Services District CA4900536 | 533 | 0 | 0 | 0 | 3.8 ppbbelow the action level |
| Armstrong Valley-Cal Water Service (Puc) CA4910018 | 473 | 0 | 0 | 0 | 3.2 ppbbelow the action level |
| Willowside Mutual Water Company CA4900561 | 448 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Bennett Ridge Mutual Water Company CA4900585 | 439 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Sereno del Mar Water Company (Puc) CA4900647 | 435 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Sonoma County Csa 41-Salmon Creek CA4900543 | 427 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Santa Rosa Mobile Estates CA4900796 | 420 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Alliance Redwoods Conference Grounds CA4900943 | 418 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Leisure Mobile Home Park CA4900832 | 410 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Heights Mutual Water Company CA4900612 | 363 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Colonial Park CA4900721 | 342 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Holland Heights Mutual Water Company CA4900548 | 300 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Palomino Lakes Mutual Water Co. CA4900570 | 300 | 0 | 0 | 0 | 5.4 ppbbelow the action level |
| Gill Creek Mutual Water Company CA4900521 | 290 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Sonoma County Csa 41-Freestone CA4900549 | 290 | 0 | 0 | 0 | 6 ppbbelow the action level |
| Carmet By the Sea Water Company CA4900578 | 288 | 0 | 0 | 0 | 2.2 ppbbelow the action level |
| Belmont Terrace Mutual Water Company CA4900558 | 287 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Happy Acres Mutual Benefit Water System CA4900512 | 260 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Mountain View Mobile Estates, LLC CA4900798 | 250 | 0 | 0 | 0 | 0 ppbbelow the action level |
| College Park Mutual Water Company CA4900667 | 244 | 0 | 0 | 0 | 0 ppbbelow the action level |
| North Star Mobile Home Park CA4900797 | 221 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Lawndale Mutual Water Company CA4900588 | 218 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Rains Creek Water District CA4900611 | 208 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Yulupa Mutual Water Company CA4900660 | 200 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Stonegate Mobile Home Park CA4900795 | 196 | 0 | 0 | 0 | 18 ppbat or above the action level |
| Shamrock Mobile Home Park CA4900723 | 188 | 0 | 0 | 0 | 6 ppbbelow the action level |
| Sonoma Mountain County Water District CA4900580 | 181 | 0 | 0 | 0 | 8 ppbbelow the action level |
| Rio Lindo Adventist Academy CA4900577 | 178 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Austin Creek Mutual (Springhill) CA4900630 | 150 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Mission Highlands Mutual Water Co. CA4900563 | 150 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Riebli Mutual Water Company CA4900603 | 150 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Roseland Mobile Home Park CA4900675 | 130 | 0 | 0 | 0 | 0 ppbbelow the action level |
| End-O-Valley Mutual Water Company CA4900547 | 129 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Fircrest Mutual Water Company CA4900559 | 126 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Downtown Graton Mutual Water System CA4901246 | 115 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Brand Water Company CA4900587 | 112 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Hilton Mutual Water Company CA4901309 | 100 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Sunrise Mountain Mutual Water Company CA4900641 | 100 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Rancho del Paradiso-Cal Water Svc (Puc) CA4900514 | 94 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Michele Mutual Water Company CA4900552 | 93 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Blue Spruce Mobile Home Park CA4900789 | 90 | 0 | 0 | 0 | 3.2 ppbbelow the action level |
| Russian River Mutual Water Co. CA4900665 | 87 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Austin Acres Mutual Water Company CA4900620 | 82 | 0 | 0 | 0 | 4.6 ppbbelow the action level |
| Wendell Lane Mutual Water Company CA4900669 | 82 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Hawkins Water Co-Cal Water Service (Puc) CA4900546 | 81 | 0 | 0 | 0 | 1.3 ppbbelow the action level |
| Sobre Vista Water Company CA4900901 | 80 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Noel Heights-Cal Water Service (Puc) CA4900785 | 79 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Madrone Mutual Water Company CA4900513 | 76 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Wilshire Heights Mutual Water Company CA4900573 | 70 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Evergreen Mobile Estates CA4900728 | 65 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Lone Pine Mutual Water Company CA4900653 | 65 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Melita Heights Mutual Water Company CA4900551 | 64 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Mark West Acres Mwc CA4900605 | 61 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Boulevard Heights Mutual Water CA4901071 | 60 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Terrace View Water System CA4901355 | 60 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Sonoma Springs CA4900533 | 59 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Lichau Hylands Mutual Water Company CA4901381 | 56 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Athena Terrace Mutual Water Company CA4900673 | 50 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Graton Mutual Water System CA4901221 | 50 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Kinnybrook Mutual Water Company CA4901062 | 48 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Huckleberry Mutual Water Company CA4900634 | 45 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Summit View Ranch Mutual Water Co. CA4900892 | 45 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Vinehill Vistas Mutual Water Company CA4900793 | 42 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Clear Creek Water Company CA4900736 | 40 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Crystals CA4901595 | 40 | 0 | 0 | 0 | 0 ppbbelow the action level |
| West Water Company (Puc) CA4900893 | 40 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Odiyan Buddhist Retreat Center CA4901314 | 35 | 0 | 0 | 0 | 4 ppbbelow the action level |
| Larkin Woods Mutual Water Company CA4900582 | 34 | 0 | 0 | 0 | 4.2 ppbbelow the action level |
| Redwood Heights Mutual Water Company CA4900639 | 30 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Alexander Valley Acres Water Company CA4900646 | 27 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Pine Hill Terrace Mobile Home Park CA4900674 | 27 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Rolling Oaks Road Association CA4900846 | 25 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Eddy Drive CA4901671 | 48 | 0 | 0 | 0 | not reported |
| Corby Avenue Apartments CA4900858 | 38 | 0 | 0 | 0 | not reported |
| Sonoma County Water Agency CA4910020 | 0 | 0 | 0 | 0 | not reported |
Shaded rows report lead at or above the 15 ppb action level in their latest monitoring period. EPA sets that level for the value 9 in 10 sampled homes fall at or below; reaching it requires the utility to act, and it is not a measurement of any single tap. One system in this table is at or above it. What an action level means
USGS · Monitoring stations
The water, more recently.
Available station readings in Sonoma County, California. Each measurement keeps its time, unit and original source.
These readings describe water at a monitoring station. They do not test your tap, measure PFAS or lead, or determine whether water is safe to drink or swim in.
Recent observations load when this section comes into view.
How these readings update
We check for updates every 10 minutes while this section is visible and show supported observations from the last 48 hours. The time beside a reading is when USGS measured it; the checked time is when our service retrieved the response. We mark a reading more than 6 hours old as older. Provisional observations can change after USGS review. A missing reading does not mean zero or clean water.
Temperature, pH, dissolved oxygen, turbidity, conductivity, streamflow and water level are shown only where a station reports them. Different measurements have different units and sampling intervals. USGS data and documentation.
Your next step
Water testing, reports & local help.
Use these official directories to find your drinking-water agency, a certified laboratory and public water records. We have not yet added an individually reviewed local resource list for this county.
Official national directories
Water testing
Find your state’s private-well program
EPA’s state directory points well owners to local program information. Services and eligibility vary by state and county.
Water testing
Find a certified drinking-water laboratory
Use EPA’s directory to reach your state’s laboratory certification program. EPA does not provide on-request testing of residential drinking water.
Public records
Find your utility’s Consumer Confidence Report
EPA links to community water-system reports and explains how to read them. Look for your actual supplier rather than assuming every address in a county shares one system.
Public records
Explore USGS water observations
Find current and historical observations from USGS monitoring locations, including available stream, lake, and groundwater data. Measurements vary by station and do not replace a test of your household water.
A county overview cannot identify every property’s water provider. If you use a public water system, confirm its name on your bill and request its annual Consumer Confidence Report. Private wells need their own testing; public-system records do not describe a private well.
Understand water testing and laboratory reportsResource descriptions are compiled by Tap Water Lookup. Review dates describe our source check, not a new water sample. How we review sources · Suggest a correction
Explore your area
Local coverage in Sonoma County
38ZIP areas in this overview
Explore the water-system records, recent station readings and testing resources on this county page. They describe the systems and stations identified in each section; they are not a separate water test for every community.
Towns and communities
- Bodega
- Bodega Bay
- Calistoga
- Cazadero
- Cloverdale
- Cotati
- Forestville
- Fulton
- Geyserville
- Glen Ellen
- Graton
- Guerneville
- Healdsburg
- Kenwood
- Monte Rio
- Occidental
- Penngrove
- Petaluma
- Rohnert Park
- Santa Rosa
- Sea Ranch
- Sonoma
- Timber Cove
- Windsor
View ZIP areas and understand coverage
- 94515Calistoga
- 94922Bodega
- 94923Bodega Bay
- 94928Rohnert Park
- 94931Cotati
- 94951Penngrove
- 94954Petaluma
- 94972Bodega
- 95401Santa Rosa
- 95403Santa Rosa
- 95404Santa Rosa
- 95405Santa Rosa
- 95407Santa Rosa
- 95409Santa Rosa
- 95412
- 95419Occidental
- 95421Cazadero
- 95425Cloverdale
- 95430Monte Rio
- 95431
- 95436Forestville
- 95439Fulton
- 95441Geyserville
- 95442Glen Ellen
- 95444Graton
- 95446Guerneville
- 95448Healdsburg
- 95450Timber Cove
- 95452Kenwood
- 95462Monte Rio
- 95465Bodega
- 95471Guerneville
- 95472Occidental
- 95476Sonoma
- 95480
- 95486Monte Rio
- 95492Windsor
- 95497Sea Ranch
These Census ZIP Code Tabulation Areas are grouped here by their largest county overlap. A ZIP area can cross county lines and contain several water suppliers or private wells. Place labels reflect Census geography, not verified postal city names or utility service boundaries.
Records for these areas are currently presented in this county overview rather than individual ZIP reports. An unpublished report does not mean there are no water records. Confirm your supplier on your water bill; if you use a private well, testing your own well is the relevant next step.
Sources and scope
EPA UCMR 5 occurrence data, samples collected 2023-01-03 – 2026-06-17, final release, August 2026 (file dated Aug 28, 2026); EPA SDWIS via ECHO, 2026Q2 extract (file dated Jul 9, 2026); EPA service-area boundaries v3.0; Census 2020 ZCTAs. Database prepared 2026-09-03.
Counts cover the systems that report this county to EPA. A water system may cross county lines. "Found" means at least one result at or above the laboratory reporting level; it is not a compliance finding.
Compiled by Tap Water Lookup from the sources identified on this page. Read the methodology and review process.