Benton County, Arkansas: drinking water report. Benton County in northwest Arkansas is one of the fastest-growing counties in the region, with a population…
Benton County in northwest Arkansas is one of the fastest-growing counties in the region, with a population nearing 300,000. The county is home to Bentonville (Walmart headquarters), Rogers, and part of Fayetteville. Beaver Lake, a U.S. Army Corps of Engineers reservoir on the White River, serves as the primary drinking water source for the region. The Benton-Washington Regional Public Water Authority and the Beaver Water District treat and distribute water to the county's rapidly expanding population.
Beaver Lake's water quality faces pressure from the poultry industry that dominates the region's agriculture. According to the Arkansas Department of Health's 2024 monitoring report, phosphorus levels in tributaries feeding Beaver Lake have been elevated for years, contributing to algal growth that complicates treatment. A 2023 study by the U.S. Geological Survey found that nutrient loading in the Illinois River basin – which drains into the lake – exceeded recommended levels for drinking water reservoirs.
The EPA's UCMR5 data shows low-level PFAS detections in the Beaver Water District system. While the region lacks military PFAS sources, the concentration of food processing and packaging operations in the area introduces PFAS through wastewater discharges. Rapid development is also adding impervious surfaces that increase stormwater runoff into the lake.
Benton County's growth is outpacing its water infrastructure planning in some areas. New subdivisions that connect to existing systems can strain treatment capacity, particularly during peak demand periods in summer.
Check your water to see current data for your provider. For nutrient-related taste and odor issues, a carbon block filter improves the water at the tap. For PFAS, reverse osmosis is more effective. Our water filter guide explains the difference. Pull your detailed report for historical data, and see our Arkansas page for statewide patterns.
Drinking water is one exposure route. These federal datasets also cover Benton County, AR.
The EPA places Benton County, AR 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.
20% of homes in Benton County, AR were built before 1980, and 3% 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 Benton County, AR averages 8.4 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