Well water in Naugatuck Valley Planning Region, Connecticut

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Testing recommended

tested well samples in Naugatuck Valley Planning Region exceeded the EPA limit for nitrate (10 mg/L), based on public data from USGS Water Quality Portal and Connecticut DPH and USGS arsenic and uranium survey.

2,521 test results across 13 contaminants from at least 218 wells, 1954 to 2017; nitrate has the most at 455. Data refreshed September 3, 2026.

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

What individual samples found

Each row summarizes every public sample for that contaminant inside Naugatuck Valley Planning Region. 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
Nitrate 1954 to 2017	12%	455	92%	1.8	84.2	10 mg/L EPA limit
E. coli 2002 to 2017	8%	13	8%	0	11	0 MPN/100mL EPA limit
Arsenic 1971 to 2017	2%	208	29%	0	470	10 ug/L EPA limit
Uranium 1988 to 2017	1%	156	62%	0.071	174	30 ug/L EPA limit
Lead 1966 to 2017	<1%	106	47%	0	20	15 ug/L EPA limit
Copper 1954 to 2017	<1%	127	76%	0.001	4	1.3 mg/L EPA limit
Fluoride 1954 to 2017	0%	181	48%	0	1.2	4 mg/L EPA limit
Radium (226 + 228) 1988 to 2017	0%	74	61%	0.045	1.1	5 pCi/L EPA limit
Chloride 1954 to 2017	no limit	347	100%	17.6	2,500	250 mg/L nuisance level
Manganese 1954 to 2017	no limit	290	97%	30	15,800	300 ug/L health guideline
Iron 1954 to 2017	no limit	290	86%	30	26,500	300 ug/L nuisance level
Sodium 1954 to 2017	no limit	221	100%	11.1	465	20 mg/L health guideline
Radon 1989 to 2005	no limit	53	100%	1,260	650,000	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	13%231 samples	10%214 samples	30%10 samples	n/a
Arsenic	2%54 samples	0%58 samples	3%96 samples	n/a
Fluoride	0%68 samples	0%108 samples	n/a	n/a
Uranium	n/a	0%58 samples	2%90 samples	n/a
Copper	2%64 samples	0%58 samples	n/a	n/a
Lead	2%43 samples	0%58 samples	n/a	n/a

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

Closer than the county

See the sampled wells near your address

The same records, drawn around one point: which wells within a few miles were sampled and what they found, how deep the wells next to you were drilled, and any leaking tank or cleanup site within a mile.

Check my address

What this means

The contaminants most often above their limit here are nitrate (12% of 455 samples), e. coli (8% of 13 samples), and arsenic (2% of 208 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, Manganese, and Iron 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 Naugatuck Valley Planning Region

1
Nitrate
12% of 455 local samples were above the limit.
2
E. coli
8% of 13 local samples were above the limit.
3
Arsenic
2% of 208 local samples were above the limit.
4
Uranium
1% of 156 local samples were above the limit.
5
Lead
<1% of 106 local samples were above the limit.
6
Copper
<1% of 127 local samples were above the limit.
7
Radon
Median local reading is 1,260 pCi/L.
8
Volatile organic compounds (VOCs)
984 leaking underground storage tank sites on record locally.
9
Metals panel
22 hazardous waste sites on record locally.

Test your Naugatuck Valley Planning Region well for nitrate, E. coli 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 Connecticut: certified labs, state programs and prices.

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

Wells in Naugatuck Valley Planning Region

192 domestic wells in Naugatuck Valley Planning Region are on record with the state since 1926. the typical well is 405 feet deep (one in ten goes past 705 feet).

In a typical Naugatuck Valley Planning Region well, the median yield is 4.9 gallons per minute, 35% of wells yield under 3 gallons per minute and usually need a storage tank.

2010s

184

2020s

Find your own well's report

The state keeps the driller's report for most wells drilled since 1984. It tells you how deep your well is, where bedrock starts, and how much water it makes, which decides what treatment can work.

Open Connecticut well completion reports and choose Water Well.
The report lists depth, depth to rock, casing, static water level and yield.

Only reports filed online since January 2021 are here; older paper reports are held by the Department of Consumer Protection.

The rock under Naugatuck Valley Planning Region

Not a principal aquifer

The USGS map places this area outside any principal aquifer, which usually means wells here draw from fractured bedrock or thin local deposits rather than a large regional aquifer. Bedrock wells of that kind are where arsenic, radon and uranium turn up, and yields vary from well to well.

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

Official help in Connecticut

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.

Private Wells, CT DPH
Environmental Laboratory Certification, CT DPH

Contamination sources on record in Naugatuck Valley Planning Region

CT DEEP contaminated sites and landfills records 984 leaking underground storage tank sites, 22 hazardous waste sites, and 46 reported spills and releases in Naugatuck Valley Planning Region, among 2,229 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.

984: leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
22: hazardous waste sitesSolvents, degreasers and metals from industrial sites can travel far in fractured bedrock.
46: reported spills and releasesMost spills are fuel; a few are solvents or chemicals that reach the water table.
34: lined landfills and transfer facilities
1,143: other remediation projects

Treatment that fits the local profile

Nitrate

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

E. coli

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

Arsenic

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

Uranium

Point-of-use reverse osmosis; Anion exchange; Whole-house anion exchange

Lead

Point-of-use reverse osmosis; Certified lead-removal carbon filter; Neutralizing filter to raise pH and stop leaching

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 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 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 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 lead

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 lead

Acid neutralizing filter

whole-house, at the point of entry, about $1,200

Raises pH so plumbing stops leaching lead and copper.

Free, no obligation

Get on the list for a free in-home water test in Naugatuck Valley Planning Region

No water treatment company serves Naugatuck Valley Planning Region through Well Water Nerd yet. We are signing licensed companies on county by county: they test at your tap for free, walk you through the numbers, and quote treatment only if something needs fixing. Leave your details and you are first in line. Nothing is shared until a company joins for Naugatuck Valley Planning Region, and you get an email naming it first.

Common questions

How deep are wells in Naugatuck Valley Planning Region?

The typical domestic well in Naugatuck Valley Planning Region is 405 feet deep, based on 192 wells reported to the state since 1926. One in ten is deeper than 705 feet.

Is there arsenic in well water in Naugatuck Valley Planning Region?

Arsenic was detected in 29% of 208 public well samples in Naugatuck Valley Planning Region, and 2% 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 Naugatuck Valley Planning Region?

The median radon level across 53 public samples in Naugatuck Valley Planning Region was 1,260 pCi/L, with a high of 650,000 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.

How often should I test a private well in Naugatuck Valley Planning Region?

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.

Towns in Naugatuck Valley Planning Region

15 towns have fewer than 30 public samples and are included in the Naugatuck Valley Planning Region totals above rather than shown separately: Ansonia, Beacon Falls, Bethlehem, Cheshire, Derby, Middlebury, Naugatuck, Oxford, Plymouth, Prospect, Seymour, Shelton, Thomaston, Watertown, Wolcott.

Planning regions near Naugatuck Valley Planning Region

Closest first. Groundwater does not stop at a line on a map, so the next planning region over is a fair second opinion.

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

Sources

USGS Water Quality Portal: 2,345 samples in Naugatuck Valley Planning Region. Data from the Water Quality Portal, a service of USGS, EPA and USDA; groundwater samples collected by USGS and cooperators. Retrieved September 3, 2026.
Connecticut DPH and USGS arsenic and uranium survey: 176 samples in Naugatuck Valley Planning Region. Arsenic and uranium in 674 private bedrock wells sampled by the Connecticut Department of Public Health with the U.S. Geological Survey, 2013 to 2015. Retrieved .
Connecticut well completion reports: 589 well records in Naugatuck Valley Planning Region, 192 domestic. Well completion reports filed online with the Connecticut Department of Consumer Protection since January 2021. Only aggregates are shown; owner names and addresses are never stored. Retrieved September 16, 2026.
CT DEEP contaminated sites and landfills: 2,229 regulated sites located in Naugatuck Valley Planning Region. Contaminated or potentially contaminated sites and solid waste landfills from the Connecticut Department of Energy and Environmental Protection. Retrieved September 16, 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.