Tennessee Private Well Water Quality 2026

PFAS in Tennessee Well Water

Tennessee has no state-level maximum contaminant levels for PFAS in any water source — public or private. TDEC ran a comprehensive statewide source water sampling initiative from August 2023 through October 2025, collecting over 1,400 samples across all public drinking water systems. That programme covers public water only. Private wells are entirely outside its scope.

Independent testing by the Sierra Club Tennessee, published in December 2023, found PFAS contamination in 60% of surface water samples collected across Northeast Tennessee around Kingsport and Johnson City. Contamination was consistently higher downstream of industrial sites, military facilities, and wastewater treatment plants — all sources that can migrate into shallow groundwater and reach private wells.

Key PFAS contamination sources identified in Tennessee include:

• Holston Army Ammunition Plant, Kingsport (Sullivan & Hawkins Counties) — The Sierra Club found the highest PFAS concentrations in their study in the Holston River immediately downstream of this facility. A PFAS compound detected only at this location also appeared in the drinking water intake of the First Utility District of Hawkins County, which draws from directly downriver of the plant. That intake recorded 13.2 ppt total PFAS — above the current federal limit of 4 ppt for PFOA and PFOS. The plant burns up to 1.25 million pounds of munitions annually. PFAS were detected on site in 2023, triggering a CERCLA Preliminary Assessment/Site Inspection. Surface water contamination at this level poses a genuine risk to nearby groundwater and private wells.
• Arnold Air Force Base, Tullahoma (Coffee & Franklin Counties) — Department of Defense testing data revealed PFAS in groundwater below Arnold’s former fire training area at concentrations 2,500 times higher than the EPA’s health advisory limit, according to WPLN’s investigation. The Air Force sent PFAS notification letters to 375 landowners in the surrounding area — the largest single-county notification total in the country at that time. The base spans Coffee and Franklin counties near Tullahoma in Middle Tennessee.
• Other confirmed Tennessee military PFAS sites — PFAS has been confirmed at a total of at least five Tennessee military installations, including Berry Field Air National Guard Base in Nashville, McGhee Tyson Air National Guard Base in Knoxville, and Naval Support Activity Mid-South in Millington. Each represents a potential source of groundwater contamination for nearby private wells.
• Biosolids land application — statewide — Class B sewage sludge is routinely spread on Tennessee farmland. Sierra Club testing of Bristol wastewater treatment plant sludge found high PFAS concentrations. A private well sampled in the midst of active sludge application fields had PFAS concentrations exceeding the EPA’s PFOA drinking water standard. This is a risk for rural wells across all three of Tennessee’s grand divisions wherever biosolids are applied to land.
• Thomas Creek, Sullivan County — The highest total PFAS concentration in the Sierra Club study (14.4 ppt) was measured here, with biosolids land application on surrounding farmland identified as the likely source.

Vanderbilt University’s Drinking Water Justice Lab received an 18-month TDEC grant in 2024 to identify Tennessee communities at greatest risk from PFAS. The work is ongoing, and the full extent of private well exposure across the state has not yet been mapped.

Karst Geology: Tennessee’s Hidden Bacteria Problem

Middle and East Tennessee sit on extensive karst terrain — a limestone landscape characterised by caves, sinkholes, fissures and underground streams. TDEC specifically flags karst areas as high risk for well contamination: water in karst moves quickly through underground fractures, carrying surface contaminants — bacteria, pathogens, nitrate, pesticides — directly into groundwater with very little natural filtration.

A peer-reviewed 2022 study published in the journal Geosciences tested 50 springs across six Northeast Tennessee counties (Carter, Greene, Hamblen, Sullivan, Unicoi and Washington). Every single spring contained fecal coliform bacteria. 90% contained E. coli. The study found an E. coli hotspot on the border of Washington and Sullivan Counties, in an area of high agricultural land use. Radon concentrations exceeded the EPA’s proposed maximum contaminant level of 300 pCi/L in 60% of the springs tested — a significant radioactive contamination risk for well owners across this region.

Wells in karst areas are considered to be under the direct influence of surface water — meaning contamination events above ground (flooding, agricultural runoff, septic overflow) can translate rapidly into contamination underground. USGS research in East Tennessee karst aquifers has confirmed the presence of culturable enteric viruses alongside fecal indicator bacteria, with dye tracer tests demonstrating that household septic systems can directly contaminate nearby private wells.

Tennessee regulations require at least 50 feet of separation between a well and a septic tank or drain field, but many older properties — particularly in rural East and Middle Tennessee — do not meet that standard. There are also thousands of abandoned wells across the state with no formal identification or closure programme, representing open contamination pathways into groundwater.

Nitrate and Agricultural Contamination

West Tennessee’s fertile agricultural land creates a documented nitrate risk for private wells. A USGS investigation of the Beaver Creek watershed in West Tennessee found that nitrate concentrations exceeding 13 mg/L — above the 10 mg/L federal MCL — were detected in 71 out of 91 sampled wells. Fertiliser and pesticide application in rural counties drives runoff into shallow groundwater, particularly in the flat sand aquifer geology that dominates western parts of the state.

In Middle Tennessee, USGS sampling of the Mississippian carbonate aquifer found that nitrate and fecal indicator bacteria were frequently detected in domestic wells, with nitrate exceeding the federal 10 mg/L MCL in two sampled wells. High nitrate is a particular danger for infants under six months — it can cause methemoglobinemia (blue baby syndrome), a condition that restricts the blood’s ability to carry oxygen.

Radon: An Underrecognised Risk in East Tennessee Wells

Radon is a naturally occurring radioactive gas produced by the decay of uranium in bedrock. In East Tennessee’s crystalline rock and carbonate geology — particularly the Valley and Ridge and Southern Blue Ridge provinces — shale formations containing low-level uranium are common. Radon dissolves into groundwater and enters homes through both the water supply and the air that rises from the water surface indoors.

The 2022 Northeast Tennessee spring study found radon levels exceeded the proposed EPA MCL of 300 pCi/L in 60% of springs, with one spring in Unicoi County exceeding 1,000 pCi/L. Radon is the leading cause of lung cancer among non-smokers in the US. Well owners in East Tennessee should include radon in any comprehensive well water test.

Regulatory Situation for Tennessee Well Owners

Private wells in Tennessee are regulated only for how they are constructed — not for the quality of water they produce. TDEC licenses well drillers and sets construction standards, but there is no state requirement for well owners to test their water and no system to notify well owners when nearby contamination is identified.

Tennessee has no state PFAS maximum contaminant levels for any water source. The state relies entirely on the federal EPA standard of 4 ppt for PFOA and PFOS, which applies only to public water systems and has a compliance deadline extended to 2031. For private well owners, there is no legal protection and no monitoring requirement whatsoever.

TDEC does not have funding programmes to assist with private well testing or remediation. If you need help locating a certified laboratory, your local county health department is the first point of contact. A certified lab list is maintained by the TDEC Laboratory Certification Programme.

Check our Tennessee municipal water quality page for city-by-city tap water data, including Nashville, Memphis and Knoxville, or use our live boil water notice tracker for active advisories across the state.

Known High-Risk Areas in Tennessee

If you live near any of the following locations, well water testing is urgent — not precautionary.

How to Test Your Tennessee Well Water — and What to Do Next

Tennessee does not require private well owners to test their water, and there is no notification system in place when contamination is found near your property. The responsibility falls entirely on you. Given the combination of karst geology, PFAS sources at multiple military and industrial sites, agricultural nitrate risk, and radon in East Tennessee, every well owner in the state should establish a regular testing routine.

Start by contacting your local county health department, who can advise on certified laboratories in your area. TDEC’s Laboratory Certification Programme maintains a full list of approved labs at tn.gov/environment. For any property near a known contamination area — military base, industrial site, or active biosolids application — PFAS testing should be treated as a priority, not a precaution.

For filter options, our well water filter guide covers reverse osmosis for PFAS, UV disinfection for bacteria, and whole-house well systems for comprehensive protection. You can also browse our full water filter solutions page or check your ZIP code for local water quality context.

For other Southeast well water risks, see our pages on North Carolina wells, Georgia wells, Virginia wells and Alabama wells. Return to the private well water directory to find your state.