Well Water Notebook
Information only, not medical advice. We never say whether your water is safe to drink. Ask a state-certified lab or your local health department. Disclaimer

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Well water testing in Tulare County, California

Tulare County Environmental Health calls nitrate the county's most prevalent contaminant, and it runs a voluntary program to sample private wells. Here's who permits wells, where to get free or low-cost testing, what to test for and where to find a lab, with a source for every fact.

This page can't tell you whether your water is safe to drink. Only a test of your well can do that.

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How many people here use a private well

USGS estimates that about 65,000 people in Tulare County supplied their own household water in 2015, about 14% of the county's population.1

Who regulates wells in Tulare County

The State of California doesn't regulate water quality in private domestic wells.2 Tulare County Environmental Health requires a permit to construct, destroy or inactivate a water well anywhere in the county, and all well work must be done by a contractor with a C-57 license. Apply online at tcpermits.com or at the Government Plaza Building, 5957 S Mooney Blvd., Visalia.3

Testing through the county

Tulare County Environmental Health runs a voluntary water well testing program: staff will collect samples from private domestic wells (serving one to four homes) on request, with fees paid in advance.4 Phone: (559) 624-7400.

The county encourages owners of new or deepened private wells to test for bacteria and nitrate, plus DBCP in the valley and radiological contaminants in the foothills and mountains. It says nitrate is found extensively throughout the valley and to a lesser extent in the foothills.5

Test the county names California limit
Nitrate 45 mg/L as nitrate (10 mg/L as N)6
DBCP 0.2 µg/L6
Gross alpha 15 pCi/L6
Uranium 20 pCi/L6

In the State Water Board's 2007–2017 public supply well data, Tulare County had the second-most public wells with nitrate above 10 mg/L as N (95 wells).7

Free testing and replacement water programs

The State Water Board's Well Testing Program Directory (June 2026) lists these programs for Tulare County.8 Check that your address is in the service area.

Program Area served Replacement water offered?
Community Water Center Tulare County No
Kings Water Alliance Tulare County Yes
Self-Help Enterprises (559-802-1289) Tulare County Yes
Tule Basin Water Foundation Tule Management Zone, southwest Tulare County Yes
Kaweah Water Foundation Kaweah Management Zone, north Tulare County Yes

If you rent out a home on a domestic well inside one of these program areas, AB 2454 requires you to test through the program and share results with tenants within 10 days.9 See renting out a home on a well.

Buying a home with a well in Tulare County

We didn't find a statewide rule requiring a well test at sale; the Transfer Disclosure Statement asks whether the water supply is a well.10 Ask for the well completion report, a water test (including the county's recommended tests for your area) and a flow test. See buying a home with a well.

Get quotes from local well pros

Need a well drilled, a pump fixed, your water tested or treated, or a well inspected for a home sale in Tulare County, California? Tell us what you need. With your permission, we'll try to pass your request to up to 3 local licensed or certified providers. It's free. You can also look up licensed pros yourself in our directory.

Well Water Notebook is a free information site, not a contractor, and we can't guarantee anyone will contact you. We don't sell your details or add you to a mailing list. See our privacy policy.

Where to get tested and treatment options

Labs: see accredited labs in Tulare County, from the State Water Board's ELAP data, or use the county's voluntary program above.11

Drillers: check a C-57 license with CSLB's Instant License Check.

Dry well? Report it on DWR's Dry Well Reporting System.12

If a result is high:

  1. Dieter, C.A., and others, 2018, Estimated Use of Water in the United States County-Level Data for 2015 (ver. 2.0), U.S. Geological Survey data release. https://doi.org/10.5066/F7TB15V5 ↩

  2. California State Water Resources Control Board, GAMA Program, A Guide for Private Domestic Well Owners (June 2025). https://www.waterboards.ca.gov/water_issues/programs/gama/docs/wellowner_guide.pdf ↩

  3. Tulare County Environmental Health, "Water Wells." https://tularecountyeh.org/eh/our-services/water-wells ↩

  4. Tulare County Environmental Health, "Voluntary Water Wells Testing Program." https://tularecountyeh.org/eh/our-services/water-wells/voluntary-water-wells-testing-program ↩

  5. Tulare County Environmental Health, "Water Testing for Individual Water Wells." https://tularecountyeh.org/eh/our-services/water-wells/voluntary-water-wells-testing-program/water-testing-for-individual-water-wells ↩

  6. California State Water Resources Control Board, "MCLs, DLRs, and PHGs for Regulated Drinking Water Contaminants" (updated September 2025). https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/documents/mclreview/mcls_dlrs_phgs.pdf ↩↩↩↩

  7. California State Water Resources Control Board, GAMA, "Nitrate" fact sheet (public supply well data, 2007–2017). https://www.waterboards.ca.gov/water_issues/programs/gama/docs/coc_nitrate.pdf ↩

  8. California State Water Resources Control Board, Well Testing Program Directory (spreadsheet, last updated June 2026). https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/docs/well-testing-program-directory.xlsx ↩

  9. California State Water Resources Control Board, "Rental Property Domestic Well Testing Requirements (AB 2454)." https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/private-domestic-well-testing.html ↩

  10. California Department of Real Estate, Disclosures in Real Property Transactions (RE 6). https://www.dre.ca.gov/files/pdf/re6.pdf ↩

  11. California State Water Resources Control Board, "Environmental Laboratory Accreditation Program (ELAP)." https://www.waterboards.ca.gov/drinking_water/certlic/labs/ ↩

  12. California Department of Water Resources, "Dry Well Reporting System." https://mydrywell.water.ca.gov/report/ ↩