County · California
Ventura County, California: drinking water records
Explore EPA records for 68 community water systems across 29 ZIP codes in Ventura 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 20 of the 68 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 68 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 |
|---|---|---|---|---|---|
| Ventura Water Department CA5610017 | 113,500 | 360 | 2 | 1 | 0 ppbbelow the action level |
| Casitas Municipal Water Dist CA5610024 | 11,005 | 240 | 0 | 1 | 0 ppbbelow the action level |
| Ventura River Water District CA5610022 | 6,100 | 240 | 0 | 3 | 0 ppbbelow the action level |
| Oxnard Water Dept CA5610007 | 200,232 | 360 | 0 | 0 | 2.2 ppbbelow the action level |
| Ventura Wwd No. 8 - Simi Valley CA5610023 | 94,738 | 180 | 0 | 0 | 0 ppbbelow the action level |
| Cal American Water Co CA5610040 | 66,809 | 120 | 0 | 0 | 3 ppbbelow the action level |
| City of Thousand Oaks Water Department CA5610020 | 53,157 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Camarillo Water Dept CA5610019 | 46,824 | 310 | 0 | 0 | 0 ppbbelow the action level |
| Golden State Water Company - Simi Valley CA5610059 | 45,128 | 180 | 0 | 0 | 0 ppbbelow the action level |
| Ventura Cwwd No. 1 - Moorpark CA5610018 | 35,514 | 270 | 0 | 0 | 0 ppbbelow the action level |
| Camrosa Water District CA5610063 | 32,700 | 360 | 2 | 0 | 0 ppbbelow the action level |
| City of Santa Paula CA5610011 | 31,018 | 180 | 0 | 0 | 0 ppbbelow the action level |
| Port Hueneme City Water Dept CA5610009 | 21,407 | 120 | 0 | 0 | 0 ppbbelow the action level |
| California Water Service Co - Westlake CA5610016 | 19,533 | 120 | 0 | 0 | 3 ppbbelow the action level |
| Fillmore Water Dept CA5610002 | 16,419 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Triunfo Water & Sanitation District CA5610043 | 13,898 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Ojai Water System CA5610014 | 6,801 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Naval Base Ventura County, Point Mugu CA5610700 | 5,700 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Pleasant Valley Mutual Water Co CA5610008 | 5,000 | 240 | 5 | 0 | 0 ppbbelow the action level |
| Channel Islands Beach CSD CA5610039 | 4,560 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Meiners Oaks Cwd CA5610005 | 4,200 | 360 | 0 | 0 | 0 ppbbelow the action level |
| Vineyard Avenue Acres Mwc CA5610029 | 1,820 | 0 | 0 | 2 | 0 ppbbelow the action level |
| Vineyard Ave Estates Mwc CA5610056 | 1,200 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Senior Canyon Mutual Water Co CA5601117 | 800 | 0 | 0 | 2 | 0 ppbbelow the action level |
| Siete Robles Mutual Water Co CA5601119 | 323 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Casitas Mutual Water Company CA5601104 | 238 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Del Norte Mutual Water Co. CA5602104 | 215 | 0 | 0 | 4 | 0 ppbbelow the action level |
| Saticoy Country Club-City of Ventura CA5602140 | 196 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Navalair Mobile Home Park CA5602110 | 160 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Siesta Mobile Home Park CA5602109 | 160 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Elkins Ranch CA5601134 | 150 | 0 | 0 | 2 | 0 ppbbelow the action level |
| Esterina Properties CA5602101 | 50 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Krotona Institute CA5601401 | 30 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Rincon Water & Road Works CA5601137 | 25 | 0 | 0 | 6 | 0 ppbbelow the action level |
| Naval Base Ventura County, Port Hueneme CA5610701 | 8,625 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Crestview Mutual Water Co CA5610058 | 2,079 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Cal American Wc - Las Posas Estates CA5610081 | 2,039 | 0 | 0 | 0 | 1 ppbbelow the action level |
| Cal American Water Company - Piru CA5610021 | 2,003 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Ventura Cwwd No. 17 - Bell Canyon CA5610003 | 1,946 | 0 | 0 | 0 | 8 ppbbelow the action level |
| Ventura Cwwd No. 38 - Lake Sherwood CA5610069 | 1,759 | 0 | 0 | 0 | 7 ppbbelow the action level |
| Cal American Wc - Rio Plaza CA5610010 | 1,709 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Ventura Cwwd No. 19 - Somis CA5610015 | 1,429 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Garden Acres Mutual Water Co CA5602108 | 1,335 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Limoneira Ranch #1 CA5601201 | 1,187 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Dempsey Road Mutual Water Co CA5610001 | 990 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Rio Manor Mutual Water Co CA5610035 | 983 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Nyeland Acres Mutual Water Co CA5602111 | 975 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Cal American - Yerba Buena CA5610006 | 690 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Brandeis Bardin Institute CA5603301 | 665 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Rancho Sespe Workers Imp Assoc CA5601144 | 600 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Cloverdale Mutual Water Co. CA5610068 | 455 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Strickland Mutual Water Company CA5602117 | 429 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Saviers Road Mutual Water Co CA5602115 | 368 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Fillmore Irrigation Co CA5601105 | 353 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Sisar Mutual Water Co CA5601120 | 340 | 0 | 0 | 0 | 0 ppbbelow the action level |
| U.S.N., San Nicolas Island CA5610702 | 254 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Cypress Mutual Water Co INC CA5602103 | 224 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Middle Road Mutual Water Co CA5601110 | 134 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Solano Verde Mutual Water Co CA5602130 | 100 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Alturas Fillmore MHP CA5601106 | 99 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Tico Mutual Water Co CA5601122 | 72 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Community Mutual Water Co CA5601125 | 65 | 0 | 0 | 0 | 0 ppbbelow the action level |
| South Mountain Mutual Water Co CA5601141 | 58 | 0 | 0 | 0 | 0 ppbbelow the action level |
| San Cayetano Mutual Water Co CA5601116 | 43 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Waters Road Domestic Users Group CA5602132 | 25 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Calleguas Municipal Water Dist CA5610050 | 0 | 0 | 0 | 0 | not reported |
| Port Hueneme Water Agency CA5610080 | 0 | 0 | 0 | 0 | not reported |
| United Wtr Cons Dist CA5610046 | 0 | 0 | 0 | 0 | not reported |
USGS · Monitoring stations
The water, more recently.
Available station readings in Ventura 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 Ventura County
29ZIP 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
- Camarillo
- Fillmore
- Frazier Park
- Maricopa
- Mira Monte
- Moorpark
- Oak Park
- Oak View
- Oxnard
- Piru
- Port Hueneme
- San Buenaventura (Ventura)
- Santa Paula
- Simi Valley
- Somis
- Thousand Oaks
View ZIP areas and understand coverage
- 91320Thousand Oaks
- 91360Thousand Oaks
- 91361Thousand Oaks
- 91362Thousand Oaks
- 91377Oak Park
- 93001San Buenaventura (Ventura)
- 93003San Buenaventura (Ventura)
- 93004San Buenaventura (Ventura)
- 93010Camarillo
- 93012Camarillo
- 93015Fillmore
- 93021Moorpark
- 93022Oak View
- 93023Mira Monte
- 93030Oxnard
- 93033Oxnard
- 93035Oxnard
- 93036Oxnard
- 93040Piru
- 93041Port Hueneme
- 93042Oxnard
- 93043Port Hueneme
- 93060Santa Paula
- 93063Simi Valley
- 93064
- 93065Simi Valley
- 93066Somis
- 93225Frazier Park
- 93252Maricopa
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.