Well water in Tennessee

Name: Private well water quality in Tennessee
Creator: Well Water Nerd
License: Public domain (US federal government data)

1in18

Testing recommended

tested well samples in Tennessee exceeded the EPA limit for E. coli (0 MPN/100mL), based on public data from USGS Water Quality Portal.

24,699 test results across 15 contaminants from at least 2,510 wells, 1924 to 2026; chloride has the most at 3,677. Data refreshed September 15, 2026.

Compiled by Nick at Well Water Nerd from public records. How these pages are built

An estimated 594,482 people in Tennessee get their drinking water from a private well, per USGS 2015 county water use.

Separately, the USGS national arsenic model estimates that <1% of the 594,482 people on private wells in Tennessee draw water above 10 ug/L (the model's range is <1% to 1%), from geology and well depth rather than local tests.

What individual samples found

Each row summarizes every public sample for that contaminant inside Tennessee. Above limit means above the EPA maximum contaminant level; where EPA has no enforceable limit, the row shows a health guideline or nuisance level instead.

Contaminant	Above limit	Samples	Detected	Median	Highest	Limit
E. coli 1998 to 2026	6%	159	6%	0	42	0 MPN/100mL EPA limit
Nitrate 1927 to 2026	3%	3,026	74%	0.273	130	10 mg/L EPA limit
Arsenic 1974 to 2026	3%	1,403	39%	0	450	10 ug/L EPA limit
PFOS 2019 to 2022	2%	49	8%	0	4.7	4 ng/L EPA limit
Fluoride 1928 to 2026	2%	2,967	71%	0.1	11	4 mg/L EPA limit
Lead 1967 to 2026	2%	1,642	61%	0	500	15 ug/L EPA limit
Copper 1950 to 2026	0%	1,401	60%	0	0.67	1.3 mg/L EPA limit
Uranium 1957 to 2026	0%	484	50%	0	3.18	30 ug/L EPA limit
Radium (226 + 228) 1989 to 2022	0%	365	86%	0.16	3	5 pCi/L EPA limit
PFOA 2019 to 2022	0%	49	4%	0	2.8	4 ng/L EPA limit
Chloride 1924 to 2026	no limit	3,677	100%	4.92	74,000	250 mg/L nuisance level
Iron 1924 to 2026	no limit	3,490	89%	80	390,000	300 ug/L nuisance level
Sodium 1925 to 2026	no limit	3,134	100%	7.1	42,000	20 mg/L health guideline
Manganese 1926 to 2026	no limit	2,661	84%	10	15,000	300 ug/L health guideline
Radon 1989 to 2026	no limit	192	97%	320	2,600	2,000 pCi/L health guideline

Over time

Share of samples above the limit by period. A cell needs ten samples to show; a comparison needs twenty in each period. Later periods sample fewer wells, and often the ones already known to have a problem.

Contaminant	before 2000	2000s	2010s	2020s
Nitrate	2%2,077 samples	3%321 samples	9%392 samples	6%236 samples
Fluoride	2%2,225 samples	0%283 samples	<1%289 samples	0%170 samples
Lead	2%1,009 samples	1%208 samples	<1%252 samples	0%173 samples
Arsenic	3%971 samples	7%149 samples	<1%186 samples	1%97 samples
Copper	0%1,005 samples	0%149 samples	0%150 samples	0%97 samples
Uranium	0%81 samples	0%120 samples	0%186 samples	0%97 samples

Nitrate, fluoride, lead, arsenic, copper, uranium have held within a few points between the two most recent periods with enough samples.

What this means

The contaminants most often above their limit here are e. coli (6% of 159 samples), nitrate (3% of 3,026 samples), and arsenic (3% of 1,403 samples). A well next door can differ sharply from yours because bedrock fractures, well depth and plumbing all matter, so these rates describe the area, not your tap.

Chloride, Iron, and Manganese are widespread in local groundwater. They are mainly a staining and taste problem, but high manganese also carries a health advisory for infants.

What to test for in Tennessee

1
E. coli
6% of 159 local samples were above the limit.
2
Nitrate
3% of 3,026 local samples were above the limit.
3
Arsenic
3% of 1,403 local samples were above the limit.
4
PFOS
2% of 49 local samples were above the limit.
5
Fluoride
2% of 2,967 local samples were above the limit.
6
Lead
2% of 1,642 local samples were above the limit.
7
Radon
Median local reading is 320 pCi/L.

Test your Tennessee well for E. coli, nitrate and arsenic

Certified lab analysis of your own tap water, bottles and prepaid return shipping included. The Essential well panel covers arsenic, uranium, nitrate, lead, copper, manganese, iron, sodium and bacteria; radon and PFAS are add-ons.

Order the Tap Score well water test kit, from $209 Already tested? Upload the report

Just want bacteria checked first? Tap Score coliform and E. coli test, $99. Coliform and E. coli are the tests every well needs every year.

Want a quick look before paying for a lab? Home well water test strips on Amazon check hardness, iron, pH and nitrate in minutes. They are a screen, not a result: arsenic, bacteria, uranium and PFAS need a certified lab.

Affiliate links: the merchant pays us a commission and the price is the same for you. It does not change what the data above says. As an Amazon Associate we earn from qualifying purchases.

Where to get a well tested in Tennessee: certified labs, state programs and prices.

Already have results back? Get your lab report read against the Tennessee numbers, $29. Every line explained, ranked by what matters, with the fix for each.

Free, one email

Send me the Tennessee report

The numbers above, which tests to order and where, and the treatment that fits the local profile, in one email.

The rock under Tennessee

Mississippian aquifers

Sandstone and carbonate-rock. Layered sandstone and limestone means a well may draw from either. Hardness and iron are routine, and the limestone layers can carry bacteria and nitrate from the surface quickly, so test for both yearly.

Classification from the USGS Principal Aquifers of the United States (national map, 2003 edition, GIS release 2015), read at the state centroid. A single well can sit in a different unit, especially near a boundary.

Official help in Tennessee

Two places to start that are not selling anything: the state program that answers private well questions, and its list of labs certified to run drinking water tests. A certified lab is the difference between a result you can act on and a number.

Well Water, TDEC
Lab Certification Program, TDEC

Contamination sources on record in Tennessee

TDEC underground storage tank facilities records 19,024 regulated sites in Tennessee, among 19,024 regulated sites in total. Groundwater does not follow property lines, so a well within a few hundred feet of one of these is worth testing for what that site could release.

19,024: registered underground storage tank sitesRegistered tanks are regulated and inspected; they matter most when they are old or near a shallow well.

Treatment that fits the local profile

E. coli

Shock chlorination and fix the well cap or casing; UV disinfection whole-house; Chlorination system

Nitrate

Point-of-use reverse osmosis; Anion exchange; Distillation

Arsenic

Point-of-use reverse osmosis; Adsorptive media (iron-based) whole-house; Anion exchange

PFOS

Granular activated carbon whole-house; Point-of-use reverse osmosis; Anion exchange

Fluoride

Point-of-use reverse osmosis; Activated alumina; Distillation

Systems we would look at first

Some links below are affiliate links. If you buy through one, the merchant pays us a commission at no extra cost to you. It does not change which products we list or what the data says.

For E. coli

UV disinfection system

whole-house, at the point of entry, about $900

Fix the well cap and casing first; UV keeps bacteria from returning.

For E. coli

Aquasana Rhino Well Water with UV

whole-house, at the point of entry, about $2,871

Whole-house system built for wells: sediment pre-filter, KDF and carbon, and a UV lamp rated to kill 99.99% of bacteria and viruses. It does not remove arsenic, nitrate, uranium or radon.

For nitrate

Under-sink reverse osmosis system

under-sink or countertop, about $300

Look for NSF/ANSI 58 certification listing the contaminant you need removed.

For nitrate

Aquasana SmartFlow reverse osmosis

under-sink or countertop, about $225

Certified to NSF/ANSI 58 and 53 to reduce arsenic (96%, pentavalent), fluoride (90%), lead (99%), nitrate, nitrite and PFOA/PFOS at the kitchen tap, with a remineralizer.

For arsenic

Whole-house arsenic and uranium filter

whole-house, at the point of entry, about $2,500

Adsorptive iron-based media; sized to your well yield.

For PFOS

Aquasana Claryum 3-Stage under-sink filter

under-sink or countertop, about $175

Certified to NSF/ANSI 53 to reduce 99% of lead and 99.7% of PFOA and PFOS at the tap. Not a fix for arsenic, nitrate or bacteria.

For PFOS

Whole-house PFAS carbon system

whole-house, at the point of entry, about $3,000

Granular activated carbon certified to NSF/ANSI 53 for PFOA and PFOS; replace media on schedule.

For PFOS

Aquasana HealthShield whole-house filter

whole-house, at the point of entry, about $2,099

Whole-house carbon system the maker certifies to reduce PFAS (PFOA and PFOS) and VOCs at every tap; a UV option adds bacteria protection.

Common questions

Is there arsenic in well water in Tennessee?

Arsenic was detected in 39% of 1,403 public well samples in Tennessee, and 3% were above the EPA limit of 10 ug/L. Arsenic has no taste or smell; a lab test is the only way to know your level.

How high is radon in well water in Tennessee?

The median radon level across 192 public samples in Tennessee was 320 pCi/L, with a high of 2,600 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.

How often should I test a private well in Tennessee?

Test for bacteria and nitrate every year. Test once for arsenic, uranium, radon, fluoride, manganese and PFAS, then again every three to five years or after any change in taste, color, or plumbing.

Counties in Tennessee

Want the numbers themselves? Download the Tennessee dataset as CSV, every county and town, with the sources named.

Sources

USGS Water Quality Portal: 24,699 samples in Tennessee. Data from the Water Quality Portal, a service of USGS, EPA and USDA; groundwater samples collected by USGS and cooperators. Retrieved September 3, 2026.
USGS national arsenic model (Ayotte 2017): estimated share of 594,482 people on private wells in Tennessee above 10 ug/L of arsenic, from geology, well depth and land use. County estimates of domestic well users with arsenic above 10 ug/L from the USGS national logistic regression model (Ayotte, Medalie and Qi, 2017), with private well population from the USGS 2015 county water-use compilation (Dieter and others, 2018). Retrieved September 15, 2026.
TDEC underground storage tank facilities: 19,024 regulated sites located in Tennessee. Underground storage tank facilities from the Tennessee Department of Environment and Conservation. Retrieved September 18, 2026.

Non-detects count as samples and are treated as zero when computing medians. Exactly at the limit counts as not above it. A sample belongs to the town containing the well's reported coordinates.