Central Valley Drinking Water
Nitrate Well Water Contamination Claims
If your private well or community drinking water in the Central Valley has been contaminated with nitrate, your family may have a claim against the agricultural operations responsible. We review these matters carefully, with an eye toward testing, source identification, and the real costs you have already paid.
Initial consultation is free. There is no fee unless we accept your case and recover for you.
Why this matters
Nitrate contamination of Central Valley groundwater is not theoretical. It is documented, repeatedly, by published scientific research and by community water organizations. Many rural Central Valley families rely on private wells. Many of those wells exceed the federal drinking-water standard for nitrate. The likely sources are tied to specific land uses — large dairies and concentrated animal feeding operations, manure lagoons and corrals, and fertilizer-intensive agriculture.
The legal question, when these conditions affect your household, is whether the operations responsible should bear the costs you are bearing — bottled water, treatment systems, hauled water, lost property value, and in some situations, health-related concerns.
The pattern is documented
These figures come from peer-reviewed scientific work in the San Joaquin Valley and from community water organizations. The federal drinking-water standard (MCL) for nitrate is 10 mg/L.
Source: Harter et al., San Joaquin Valley nitrate research; Kings Water Alliance. Sample populations and methodologies vary by study; the consistent finding across sources is that a substantial share of Central Valley domestic wells exceeds the nitrate MCL.
What nitrate is, in plain English
Nitrate is a chemical compound (NO3−) that can move easily through soil and into groundwater. It is invisible, tasteless, and odorless in well water. Common sources include:
- • Manure lagoons and corrals at dairies and concentrated animal feeding operations.
- • Heavy synthetic fertilizer use on row crops and orchards.
- • Septic systems in some rural settings.
- • Historical land use that left a residual loading of nitrogen in shallow groundwater.
The U.S. EPA Maximum Contaminant Level (MCL) for nitrate in drinking water is 10 mg/L (as nitrogen). The MCL was set primarily to protect infants from methemoglobinemia, sometimes called “blue baby syndrome.” Long-term exposure has been studied for other potential health concerns; the science continues to evolve and any specific health claim depends on facts and expert review.
Where the problem is showing up
Documented nitrate concerns are concentrated in the San Joaquin Valley counties listed below. These are not the only counties potentially affected; they are the ones with the strongest published evidence base.
Fresno County
Significant nitrate exceedances in domestic wells in agricultural areas.
Kings County
High exceedance rates documented in monitoring data.
Tulare County
Among the most heavily affected counties for domestic well contamination.
Merced County
Substantial exceedances near dairy and agricultural operations.
Stanislaus County
Documented contamination patterns linked to land use.
Other Central Valley areas
If you are outside these counties but have a nitrate test result above the MCL, please reach out.
Who may have a potential claim
A nitrate claim is fact-specific. Some categories of people commonly come forward:
- • Well owners with confirmed test exceedances. If your well has been tested and the result is above 10 mg/L for nitrate, you have the strongest objective starting point.
- • Families who stopped drinking their well water. If you have switched to bottled water, hauled water, or installed a treatment system because of contamination concerns, that is a documented cost.
- • Residents near likely nitrate sources. Proximity to dairies, concentrated animal feeding operations, manure lagoons, or heavily fertilized fields raises questions worth investigating.
- • Households with infants or young children. The MCL exists primarily to protect infants. Particular care is taken in these cases, and any health-related component is reviewed carefully and conservatively.
- • Tenants and mobile-home-park residents. You do not have to own the well or the property to have been harmed.
Who may be responsible
Source identification is technical work that requires testing, hydrogeology, land-use history, regulatory records, and expert review. We do not point a finger before the evidence is there. That said, the categories of potentially responsible parties commonly include:
- • Large dairies and concentrated animal feeding operations
- • Operators of manure lagoons and storage facilities
- • Fertilizer-intensive agricultural operators
- • Landowners and property operators with relevant land-use history
- • In some situations, water providers or public agencies that failed to act on known risks
Reporting in 2026 indicates that nitrate pollution remains an active regulatory issue, including a proposed California Water Board order aimed at bringing dairies into long-term nitrogen balance. This is not a closed historical problem.
How a lawyer investigates a nitrate claim
These cases live or die on the science. The work proceeds in roughly this order:
Water testing
Confirming nitrate concentrations from a properly collected sample at a certified lab. If you do not yet have a test, we discuss how to get one.
Land-use history
Identifying nearby agricultural operations, dairies, manure lagoons, and historical uses that could explain the loading.
Regulatory records
Pulling Regional Water Board, County Environmental Health, and Department of Pesticide Regulation files for nearby operators.
Hydrogeology and source tracing
Working with experts to evaluate groundwater flow, depth, and isotopic markers that distinguish manure-derived nitrate from fertilizer-derived nitrate.
Damages documentation
Capturing what your family has already spent on bottled water, treatment, hauled water, lost property value, and other measurable costs.
Legal evaluation
Determining whether the facts support a claim, who the right defendants are, and whether your matter belongs in an individual case or a coordinated proceeding.
Common questions
What if I do not know the source?
That is normal. Source identification is part of what counsel and experts do. You do not have to identify the responsible operator before contacting us. A confirmed exceedance and a description of nearby land use are usually enough to start.
What if I do not own the well?
You do not have to own the well to have been harmed by the water. Tenants, family members, and others who used the water may have claims depending on the facts.
What if I live in a rental or a mobile-home park?
Renters and mobile-home-park residents are sometimes the most affected. Park-owned wells and small water systems have their own regulatory and contractual issues. Reach out and we will discuss the specifics.
What if my contamination has been going on for years?
Long-running contamination is common and is part of the legal story, not a barrier. Whether your specific claim is timely depends on the facts and on how recent your discovery, harm, or testing is. We will look at it with you.
What if I am already getting bottled water?
Then you have already paid real, documentable costs. Save your receipts and any communications about why you switched. That documentation often strengthens a claim.
What if I do not know whether my community qualifies?
Reach out. Even if your specific area is not on a public exceedance list, a recent test result above the MCL or a documented water notice is often enough to begin.
What information helps
You do not need all of the following before reaching out. Anything you have is enough to start a conversation.
- • Address or community name and county.
- • Whether your home uses a private well, a small water system, or a community water supply.
- • Any test results you have, even if you do not understand them.
- • Approximate date(s) of any water notices, advisories, or correspondence.
- • Receipts or records of bottled water, hauled water, or treatment system costs.
- • A general sense of nearby agricultural operations, dairies, or manure lagoons if you know of any.
- • Whether anyone in the household has had health concerns you connect to the water.
Why contact our office
Attorney David L. Milligan is a Board-Certified California Civil Trial Attorney based in Fresno, with over 25 years of experience handling serious personal injury and institutional accountability cases against private companies and government entities. We are local to the Central Valley and we understand the agricultural economy that surrounds these cases.
- • Scientific approach — we work with hydrogeology and water-quality experts to evaluate source and exposure.
- • Local understanding — the Central Valley is our home; we know the operators and the regulators by name.
- • Careful screening — we take cases we are prepared to litigate, and we are honest with people we cannot help.
- • No pressure — reaching out does not commit you to anything.
Talk with our office about your water
Three ways to reach us. Use whichever feels easiest.
Option 1
Call our office
Talk through what you know. We will tell you what to do next.
(559) 439-7500Option 2
Email us
Attach test results or photos of water notices if you have them.
lawyer@callegal.comOption 3
Use the form below
Submit a brief inquiry. We will follow up by your preferred method.
Go to Form ↓If you use the form, please:
- • In Type of Incident, write “Nitrate Well Water” and your county.
- • In Date, the approximate date of any test result or water notice you received is fine.
- • In Briefly describe what happened, share whatever you know — your address or community, whether you have a private well, your test result if any, what you have been doing for drinking water, and any nearby agricultural operations or dairies.
Important: The information on this page is provided for general educational purposes only and does not constitute legal advice. Submitting an inquiry does not create an attorney–client relationship; that relationship is formed only by a written agreement signed after we evaluate the matter for conflicts and merit. Past results do not guarantee future outcomes, and no specific recovery is promised. Health-related statements describe regulatory standards and published research; whether a specific health concern is causally linked to nitrate exposure depends on the facts and on expert review. The Law Offices of David L. Milligan is licensed in California and accepts qualifying matters consistent with applicable rules of professional conduct.