Mohave County, Arizona: drinking water report. Mohave County in northwestern Arizona has about 213,000 residents spread across a vast desert landscape,
Mohave County in northwestern Arizona has about 213,000 residents spread across a vast desert landscape, with Kingman, Bullhead City, and Lake Havasu City as the major communities. Water comes from groundwater basins and Lake Havasu (a Colorado River reservoir), depending on location. The county's extreme aridity – Bullhead City regularly records the hottest temperatures in the country – makes water both scarce and mineral-heavy.
Total dissolved solids and hardness are the baseline water quality issues across Mohave County. According to ADEQ's 2024 water quality data, groundwater TDS in the Hualapai Basin exceeds 1,500 mg/L in some production zones, and multiple systems report hardness above 300 mg/L. Communities on Colorado River water from Lake Havasu receive better-quality source water, but even that supply carries elevated mineral content from the river's passage through desert geology.
The former Kingman Airport was an Army Air Corps training base during WWII and has documented AFFF use. ADEQ's 2024 PFAS investigation found PFOS at 8 ppt in monitoring wells near the airport. Naturally occurring fluoride in some Mohave County wells exceeds the MCL of 4 mg/L – a dental and skeletal health concern with long-term exposure.
Mohave County's desert groundwater requires treatment for mineral content alone, regardless of any industrial contamination. If your water leaves white or brown deposits on fixtures, those minerals are also in the water you drink.
Check your water for data at your address. Reverse osmosis is the go-to technology for high-mineral desert water and handles fluoride and PFAS at the same time. Our water filter guide covers systems designed for desert conditions. Pull your detailed report for local data, and visit our Arizona page for statewide patterns.
Drinking water is one exposure route. These federal datasets also cover Mohave County, AZ.
The EPA places Mohave County, AZ in Zone 2 - a moderate-risk category, with a predicted average indoor radon level between 2 and 4 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.
21% of homes in Mohave County, AZ were built before 1980, and 1% 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 Mohave County, AZ averages 4.7 µg/m³, within 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
Across 41 public water systems serving Mohave County, AZ with EPA lead testing on record, 4 (9.8%) reported a 90th-percentile lead result above the EPA's 15 ppb action level, and the median is 4.2 ppb. 27 water systems serving Mohave County, AZ carry a health-based EPA Safe Drinking Water Act violation.
| Most-cited violation type | Systems affected |
|---|---|
| Lead and Copper Rule Revisions | 10 |
| Ground Water Rule | 8 |
| Revised Total Coliform Rule | 8 |
| Arsenic | 3 |
| Total Coliform Rule | 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.