Kings County, California: drinking water report. Kings County in the southern San Joaquin Valley has about 152,000 residents, with Hanford as the county…
Kings County in the southern San Joaquin Valley has about 152,000 residents, with Hanford as the county seat. The county depends on groundwater for virtually all of its drinking water supply. Cotton, dairy, and processing tomatoes are the major agricultural products. The Naval Air Station Lemoore, one of the Navy's largest master jet bases, occupies a significant portion of the county's western half.
Groundwater overdraft is a structural problem in Kings County. According to the California Department of Water Resources' 2024 Sustainable Groundwater Management Act report, the Tulare Lake subbasin beneath Kings County has experienced over 50 feet of water table decline since 1960. As the water table drops, wells pull from deeper zones that may contain naturally occurring arsenic and uranium at higher concentrations.
NAS Lemoore has confirmed PFAS contamination from AFFF firefighting foam. The Navy's 2024 environmental investigation found PFOS at 85 ppt in groundwater monitoring wells near the base's fire training areas. A 2024 California State Water Board analysis identified three community water systems in Kings County with combined PFAS above the state notification level of 10 ppt.
Kings County residents face a combination of agricultural nitrate, military PFAS, and naturally occurring contaminants that become more concentrated as wells go deeper. Testing is essential regardless of whether you are on a public system or a private well.
Check your water for data at your address. For the multi-contaminant environment in Kings County, reverse osmosis is the most practical single-system solution. Our water filter guide covers options for deep-well groundwater. Get your detailed report for trends, and visit our California page for statewide patterns.
Drinking water is one exposure route. These federal datasets also cover Kings County, CA.
The EPA places Kings County, CA in Zone 3 - the EPA's lowest-risk category, with a predicted average indoor radon level below 2 pCi/L. Zone maps predict an area's radon potential from geology and existing indoor readings; they say nothing about a specific house. Testing is the only way to know your own level.
42% of homes in Kings County, CA were built before 1980, and 10% before 1950. Residential lead paint was banned in 1978, so housing age is the strongest available proxy for lead-paint exposure. This describes the county's housing stock, not any one home.
Modelled annual fine-particle pollution (PM2.5) in Kings County, CA averages 13.6 µg/m³, above the EPA's annual standard of 9 µg/m³. These are CDC modelled county estimates rather than readings from a specific monitor.
How radon zones work · Air quality by county · Lead exposure guide
12 public water systems serving Kings County, CA have EPA lead testing on record. The reported lead sample skews toward systems that already flagged a problem, so its exceedance rate is not directly comparable with other areas. 10 water systems serving Kings County, CA carry a health-based EPA Safe Drinking Water Act violation.
| Most-cited violation type | Systems affected |
|---|---|
| Total Coliform Rule | 9 |
| Total Trihalomethanes (TTHM) | 6 |
| Lead and Copper Rule Revisions | 3 |
| Arsenic | 2 |
| Haloacetic Acids (HAA5) | 2 |
Source: EPA Lead and Copper Rule 90th-percentile tap sampling and EPA SDWIS Safe Drinking Water Act enforcement records, aggregated from the public water systems serving this county. Figures are counts of water systems, not a test of any individual home or tap.