Well water in Granby, Connecticut

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Testing recommended

tested well samples in Granby 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.

254 test results across 11 contaminants from at least 35 wells, 1956 to 2017; nitrate has the most at 43. 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 Granby. 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 1956 to 2017	7%	43	98%	1.8	43	10 mg/L EPA limit
Fluoride 1956 to 2017	0%	24	96%	0.1	1	4 mg/L EPA limit
Arsenic 1988 to 2017	0%	11	9%	0	0.09	10 ug/L EPA limit
Copper 1988 to 2017	0%	10	20%	0	0.001	1.3 mg/L EPA limit
Lead 1988 to 2017	0%	10	0%	0	0	15 ug/L EPA limit
Chloride 1956 to 2017	no limit	40	100%	9.7	94	250 mg/L nuisance level
Iron 1956 to 2017	no limit	38	92%	50	1,200	300 ug/L nuisance level
Manganese 1956 to 2017	no limit	37	97%	0	910	300 ug/L health guideline
Sodium 1956 to 2017	no limit	32	100%	9.65	170	20 mg/L health guideline

Sampled fewer than 10 times, too few to summarize: Uranium (5), Radium (226 + 228) (4).

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.

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What this means

The contaminants most often above their limit here are nitrate (7% of 43 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 Granby

1
Nitrate
7% of 43 local samples were above the limit.
2
Coliform bacteria
Recommended for every private well, every year.
3
Chloride
Detected in 100% of local samples.
4
Manganese
Detected in 97% of local samples.
5
Fluoride
Detected in 96% of local samples.
6
Iron
Detected in 92% of local samples.
7
Volatile organic compounds (VOCs)
16 leaking underground storage tank sites on record locally.

Test your Granby well for nitrate, coliform bacteria and chloride

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

The rock under Granby

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 Granby

CT DEEP contaminated sites and landfills records 16 leaking underground storage tank sites in Granby, among 28 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.

16: leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
1: lined landfill or transfer facility
11: other remediation projects

Treatment that fits the local profile

Nitrate

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

Free, no obligation

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

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

Common questions

Is there arsenic in well water in Granby?

Arsenic was detected in 9% of 11 public well samples in Granby, and 0% 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 often should I test a private well in Granby?

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 Granby

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: 252 samples in Granby. 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 Granby. 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 .
CT DEEP contaminated sites and landfills: 28 regulated sites located in Granby. 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.