Environmental & Toxic Exposure
Nitrate Contamination Litigation in California
Civil litigation for California families and communities affected by nitrate contamination of groundwater — particularly in the San Joaquin Valley.
Where the science meets the law.
The contamination pattern
Published scientific research and regulatory data document substantial nitrate contamination of groundwater across California's San Joaquin Valley. In parts of Fresno, Kings, and Tulare counties, approximately 40% of sampled domestic wells exceed the federal Maximum Contaminant Level of 10 mg/L (as nitrogen). In Stanislaus and Merced, approximately 42%. In Tulare and Kings together, approximately 46%. Sources are linked to dairy and concentrated animal feeding operation manure lagoons and corrals, fertilizer-intensive agriculture, and shallow groundwater dynamics that allow contaminants to migrate readily.
Legal theories typically asserted
- Negligence — failure to operate, monitor, or contain nitrogen sources with reasonable care
- Nuisance (public and private) — substantial unreasonable interference with the use of property; California Civil Code §§ 3479, 3490, et seq.
- Trespass — physical invasion of the plaintiff's property by contaminants
- Strict liability for ultrahazardous activities (where applicable to specific operations)
- Statutory claims — including under the Porter-Cologne Water Quality Control Act (Cal. Water Code § 13000 et seq.) and the federal Clean Water Act where applicable
Categories of potentially responsible defendants
Liability is fact-specific and requires careful source identification. 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, and (in some cases) water providers or public agencies that failed to act on known risks.
Expert evidence and source identification
These cases live or die on the science. Source identification typically requires: water testing at certified labs to confirm concentrations and flag patterns; hydrogeologic analysis to map groundwater flow direction, recharge zones, and shallow vs. deep aquifer pathways; isotopic markers (δ¹⁵N and δ¹⁸O of nitrate) that distinguish manure-derived from synthetic-fertilizer-derived nitrate; land-use history from regulatory filings, aerial imagery, and historical records; and regulatory file review at the Regional Water Quality Control Board, County Environmental Health, and Department of Pesticide Regulation. We work with credentialed expert witnesses who can develop and defend these analyses.
Damages in nitrate cases
- Past and future bottled water and hauled water costs
- Treatment system installation and maintenance (reverse osmosis being the most effective for nitrate)
- Loss of property value
- Medical monitoring or health-related damages where supported by causation evidence
- Punitive damages where defendant conduct supports them (Cal. Civ. Code § 3294)
Class actions, mass torts, and individual cases
Nitrate contamination affecting multiple households in a defined area can sometimes proceed as a coordinated proceeding (JCCP), federal multi-district litigation (MDL), or class action — depending on commonality of harm, source attribution, and damages variability. Other matters proceed as individual or small-group cases. We evaluate the right vehicle case-by-case.
Related
If you are evaluating whether your well water has a nitrate problem, see our practical guide:
Central Valley Nitrate Well Water Contamination →Common Questions
What if I don't know the source of the contamination?
That is normal. Source identification is part of what counsel and experts do. You don't have to identify the responsible operator before contacting us. A confirmed exceedance and a description of nearby land use are usually enough to start.
Are these cases viable as individual claims, or do they need to be class actions?
Both routes can work depending on the facts. Individual cases work where damages are well-defined and the source is identifiable. Coordinated proceedings (JCCPs and MDLs) and class actions work where many households face similar harm from a common source. We evaluate each situation on its specifics.
What if my contamination has been going on for years?
Long-running contamination is part of the legal story, not a barrier. The applicable statute of limitations and the discovery rule depend on when the harm became reasonably knowable. We will look at the specifics.
Do you handle these cases on contingency?
Yes. Environmental contamination cases are handled on a contingency-fee basis like our other matters — there is no fee unless we recover for you.
For a confidential review of your case:
“The cases we take are cases where the medical proof can carry the damages. That is not rhetoric — it is the test every file gets at intake.”
Law Offices of David L. Milligan · Fresno, California
Important: 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. Statutory citations are illustrative; the legal framework applicable to a specific case depends on the facts. The Law Offices of David L. Milligan is licensed in California.