Vigo County, Indiana: drinking water report. Vigo County in western Indiana has about 107,000 residents, with Terre Haute as the county seat.
Vigo County in western Indiana has about 107,000 residents, with Terre Haute as the county seat. Indiana American Water draws from the Wabash River, treating water at a plant that has been upgraded in recent years. The Wabash River drains a massive agricultural and industrial watershed across central Indiana before reaching Terre Haute, carrying the accumulated runoff and discharges along the way.
The Wabash River at Terre Haute carries elevated nutrient levels from upstream agriculture. According to IDEM's 2024 watershed assessment, nitrate at the Terre Haute intake averaged 5.8 mg/L during spring – below the MCL but high enough to drive disinfection byproduct formation during treatment. Trihalomethanes in the distribution system have periodically approached the 80 ppb MCL during warm months.
The former Hulman Regional Airport and Terre Haute Air National Guard Base have documented AFFF use. A 2024 IDEM PFAS investigation found PFOS at 13 ppt in monitoring wells near the facility. The Mead Corporation's former paper mill in the county also contributed industrial contamination to the Wabash River floodplain.
Terre Haute's river-sourced water is treated to meet all standards, but the high-nutrient source water means disinfection byproducts are the most relevant household concern. These byproducts form when chlorine reacts with organic matter in the water, and concentrations tend to increase in summer.
Check your water for current results. A carbon block filter is specifically effective at reducing disinfection byproducts. For PFAS, reverse osmosis adds comprehensive protection. Our water filter guide covers both approaches. Get your detailed report for seasonal patterns, and visit our Indiana page for statewide data.
Drinking water is one exposure route. These federal datasets also cover Vigo County, IN.
The EPA places Vigo County, IN 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.
64% of homes in Vigo County, IN were built before 1980, and 31% 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 Vigo County, IN averages 8.7 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
12 public water systems serving Vigo County, IN 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. 3 water systems serving Vigo County, IN carry a health-based EPA Safe Drinking Water Act violation.
| Most-cited violation type | Systems affected |
|---|---|
| Lead and Copper Rule Revisions | 2 |
| Revised Total Coliform Rule | 1 |
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.