Well water in Mansfield, Connecticut

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Testing strongly recommended

tested well samples in Mansfield 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.

138 test results across 13 contaminants from at least 21 wells, 1963 to 2023; nitrate has the most at 30. 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 Mansfield. 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 1964 to 2023	23%	30	100%	1.33	16	10 mg/L EPA limit
Fluoride 1964 to 2023	0%	18	94%	0.07	1.3	4 mg/L EPA limit
Chloride 1963 to 2023	no limit	29	100%	11	148	250 mg/L nuisance level
Iron 1963 to 2023	no limit	18	94%	25	3,300	300 ug/L nuisance level
Manganese 1963 to 2023	no limit	17	100%	0	50	300 ug/L health guideline

Sampled fewer than 10 times, too few to summarize: Uranium (5), Arsenic (4), Copper (2), Lead (2), Radium (226 + 228) (2), E. coli (1), Sodium (9), Radon (1).

Closer than the town

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 (23% of 30 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 Mansfield

1
Nitrate
23% of 30 local samples were above the limit.
2
Coliform bacteria
Recommended for every private well, every year.
3
Radon
Median local reading is 930 pCi/L.
4
Copper
Detected in 100% of local samples.
5
Chloride
Detected in 100% of local samples.
6
Manganese
Detected in 100% of local samples.
7
Fluoride
Detected in 94% of local samples.
8
Volatile organic compounds (VOCs)
76 leaking underground storage tank sites on record locally.

Test your Mansfield well for nitrate, coliform bacteria and radon

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 Mansfield numbers, $29. Every line explained, ranked by what matters, with the fix for each.

Wells in Mansfield

44 domestic wells in Mansfield are on record with the state since 2021. the typical well is 385 feet deep (one in ten goes past 578 feet).

In a typical Mansfield well, the median yield is 8.5 gallons per minute, 9% of wells yield under 3 gallons per minute and usually need a storage tank.

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 Mansfield

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 town 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 Mansfield

CT DEEP contaminated sites and landfills records 76 leaking underground storage tank sites and 2 reported spills and releases in Mansfield, among 130 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.

76: leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
2: reported spills and releasesMost spills are fuel; a few are solvents or chemicals that reach the water table.
5: lined landfills and transfer facilities
47: other remediation projects

Treatment that fits the local profile

Nitrate

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

Iron

Oxidizing filter whole-house; Water softener (low levels); Aeration plus filtration

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 iron

Iron and manganese oxidizing filter

whole-house, at the point of entry, about $1,800

Air-injection or greensand media; fixes staining at the source.

Free, no obligation

Get on the list for a free in-home water test in Mansfield

No water treatment company serves Mansfield 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 Mansfield, and you get an email naming it first.

Common questions

How deep are wells in Mansfield?

The typical domestic well in Mansfield is 385 feet deep, based on 44 wells reported to the state since 2021. One in ten is deeper than 578 feet.

How often should I test a private well in Mansfield?

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 near Mansfield

Closest first. Groundwater does not stop at a line on a map, so the next town 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: 136 samples in Mansfield. 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: 2 samples in Mansfield. 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: 72 well records in Mansfield, 44 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: 130 regulated sites located in Mansfield. 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.