PWSID CA1510033
CWS - KERNVILLE
Community water system based in San Jose, CA
Service area on file with EPA: Kern County. EPA's recorded service area can be incomplete for regional authorities. The cities and counties above are what the utility has filed with EPA; the utility may serve additional areas.
- Population served
- 2,572
- Source
- Surface water
- Status
- Active
At a glance
2 findings worth watching
-
Public health experts agree no amount of lead in drinking water is safe. Even low levels can affect children's brain development.
Most recent lead and copper test · See details below
-
This utility's lead service line inventory is not yet complete. Federal rules required every system to publish one by October 16, 2024.
From the utility's published inventory · See details below
-
CDC's My Water's Fluoride listing marks this system as Mixed: different sources or parts of its service area report different fluoridation statuses.
Per CDC My Water's Fluoride · See details below
Risk classification follows EPA's published values for safe drinking water, with caution and concern bands reviewed by a clinician. Past resolved violations do not influence this card. See methodology.
Lead service line inventory
Service line inventory still in progress
CWS - KERNVILLE reports 0 confirmed lead service lines, 325 non-lead, 1,749 unknown (total 2,074) in the EPA SDWIS service line inventory (2026Q1). EPA's Lead and Copper Rule Revisions treat unknown and galvanized-requiring-replacement lines as lead for notification and replacement scheduling until verified.
- 0 confirmed lead service lines
- 0 galvanized requiring replacement (LCRI treats these as lead)
- 1,749 unknown (84.3% of total)
- 325 confirmed non-lead (15.7%)
- 2,074 total service lines in the system
What to do if your service line might be lead
- Ask your utility to check the service-line classification for your specific address. Many utilities provide a public address-lookup tool linked from the inventory page.
- Get on the replacement queue. Under the LCRI, utilities must replace all lead and galvanized-requiring- replacement lines within 10 years (clock generally starts November 2027). Some prioritize requests.
- Until the line is replaced: flush the tap 30 seconds after long stagnation, use cold water for drinking and cooking, and consider an NSF/ANSI 53 lead-rated tap filter.
- Talk to your clinician about a blood lead test for anyone in the home, especially a pregnant person or a child under 6. Lead in drinking water guide.
Inventory data sourced from CWS - KERNVILLE ( retrieved May 24, 2026 ; curator confidence: medium ). Confirmed against the original source automatically each month; see methodology.
Lead and copper test results
The most recent measurement per contaminant from EPA's Lead and Copper Rule sampling.
Why only lead and copper, and not arsenic, nitrate, or others?
EPA's bulk SDWIS download is the only nationwide per-system sample data they publish, and it only includes the Lead and Copper Rule table. Values for other regulated contaminants (TTHMs, nitrate, arsenic, etc.) appear on this page only when they trigger a violation. For the full per-system contaminant suite, see the utility's annual Consumer Confidence Report (link further down the page).
| Contaminant | Most recent | Date | Risk |
|---|---|---|---|
| PB90 | 0.0074 mg/L | December 31, 2025 | Caution |
Data from EPA SDWIS (Lead and Copper Rule sample table) , last refreshed May 24, 2026.
Fluoride
Per CDC My Water's Fluoride
CWS - KERNVILLE reports mixed fluoridation across its water sources.
CDC's My Water's Fluoride listing marks this system as Mixed: it draws on multiple sources with different fluoridation statuses, or fluoridates only part of its service area. The annual water quality report for your specific service address has the most reliable measured concentration.
Source: CDC My Water's Fluoride, listed under Cal Water Service Co-Kernville System (Kern County). Verify on CDC's site .
Area context
Kern County, CA (2020 data)
- Community water systems
- 24 of 144 add fluoride
- Population on fluoridated water
- 18,282 of 458,947 (4.0%)
California statewide (2020 data)
- Population on fluoridated water
- 21,879,582 of 38,051,212 (57.5%)
- Community water systems adding fluoride
- 417 of 3,057
Data from CDC My Water's Fluoride (per-system status) , last refreshed May 19, 2026.
Data from CDC Water Fluoridation Reporting System (state and county aggregates) , last refreshed May 16, 2026.
Compliance history
EPA-recorded violations against this system over the last 5 years.
How to read this section
Health-based violations are when a measured limit was exceeded; the measured concentration is shown alongside the EPA federal limit where SDWIS published it. Monitoring and reporting items are paperwork issues (missed sample dates, late filings) that do not themselves indicate unsafe water.
Clean record
No violations on file for this system in the last 5 years.
20 older violation s (5-10 years ago) · 20 health-based, 0 paperwork , all resolved
| Period start | Relates to | Item | Measured level | Status |
|---|---|---|---|---|
| October 1, 2019 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.067 MG/L
MCL 0.060 MG/L | Resolved |
| October 1, 2019 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.067 MG/L
MCL 0.060 MG/L | Resolved |
| July 1, 2019 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.061 MG/L
MCL 0.060 MG/L | Resolved |
| July 1, 2019 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.061 MG/L
MCL 0.060 MG/L | Resolved |
| April 1, 2019 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.063 MG/L
MCL 0.060 MG/L | Resolved |
| April 1, 2019 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.063 MG/L
MCL 0.060 MG/L | Resolved |
| January 1, 2018 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.064 MG/L
MCL 0.060 MG/L | Resolved |
| January 1, 2018 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.064 MG/L
MCL 0.060 MG/L | Resolved |
| October 1, 2017 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.084 MG/L
MCL 0.060 MG/L | Resolved |
| October 1, 2017 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.084 MG/L
MCL 0.060 MG/L | Resolved |
| July 1, 2017 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.069 MG/L
MCL 0.060 MG/L | Resolved |
| July 1, 2017 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.069 MG/L
MCL 0.060 MG/L | Resolved |
| April 1, 2017 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.064 MG/L
MCL 0.060 MG/L | Resolved |
| April 1, 2017 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.064 MG/L
MCL 0.060 MG/L | Resolved |
| January 1, 2017 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.072 MG/L
MCL 0.060 MG/L | Resolved |
| January 1, 2017 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.072 MG/L
MCL 0.060 MG/L | Resolved |
| October 1, 2016 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.079 MG/L
MCL 0.060 MG/L | Resolved |
| October 1, 2016 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.079 MG/L
MCL 0.060 MG/L | Resolved |
| July 1, 2016 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.080 MG/L
MCL 0.060 MG/L | Resolved |
| July 1, 2016 | Total Haloacetic Acids (Haa5) | Maximum Contaminant Level Violation, Average | 0.080 MG/L
MCL 0.060 MG/L | Resolved |
Data from EPA SDWIS (violation records) , last refreshed May 24, 2026.
Where to see every contaminant this utility tested for
EPA's bulk SDWIS dataset gives MyTapWater.us per-system measured values for lead and copper, plus violation records for everything else. To see every regulated contaminant this utility tested for in the past year (TTHMs, HAA5, nitrate, arsenic, fluoride, chromium, etc.) with measured values, read the utility's Consumer Confidence Report (CCR).
Every community water system is required by EPA to publish a CCR annually, by July 1, listing every contaminant they sampled, the measured value, the federal limit, and any health-based exceedances. Most utilities post the report online; some mail it with your bill.
How to find CWS - KERNVILLE's CCR:
- Search the web for "CWS - KERNVILLE consumer confidence report" . The PDF is usually on the utility's own website.
- Or call the utility directly. Their phone number is in the contact section below.
Other water systems in Kern County, CA
Compare nearby utilities by population served.
- CWS - BAKERSFIELD
268k served · Kern County
- BAKERSFIELD, CITY OF
160k served · BAKERSFIELD
- DELANO, CITY OF
51k served · DELANO
- OILDALE MWC
45k served · Kern County
- INDIAN WELLS VALLEY W.D.
42k served · Kern County
Contact this utility
Public administrative contact information for this water system, as filed with the EPA. Use this to ask about your service line, request your home's lead status, or report a water quality issue.
- Administrator
- JAMES, SOPHIE
- Phone
- 408-367-8593
- sjames@calwater.com
- Mailing address
- 1720 NORTH FIRST STREETSAN JOSE, CA 95112
Where this page's data comes from
Bundle released 2026-Q2, regenerated May 24, 2026. Each section above also shows its own source date so you can tell at a glance how fresh that part of the page is.
- EPA SDWIS bulk download — last refreshed May 24, 2026 (system info, violations, lead and copper samples).
- Lead service line inventory — last refreshed May 24, 2026 (from the utility's reported inventory).
- CDC My Water's Fluoride — last refreshed May 19, 2026 (per-system Yes/No fluoridation status).
- CDC Water Fluoridation Reporting System — last refreshed May 16, 2026 (state and county fluoridation aggregates).
Every value on this page is cross-verified before publication; read our methodology for the verification steps and corrections process.