Well water in Winslow township, New Jersey

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Testing recommended

private wells tested between 2002 and 2024 in Winslow township had total coliform above the New Jersey limit (any detection), according to NJDEP.

The strongest signal is radium (226 + 228): 11% of 70 local samples were above the limit, too few samples to carry the headline but first on the test list below.

1,462 private wells tested 2002 to 2024 in state summaries; 797 test results across 13 contaminants from at least 54 wells, 1960 to 2025; sodium has the most at 136. Data refreshed September 9, 2026.

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

What homeowner tests found

NJDEP Private Well Testing Act summaries: private wells tested and reported to the state, 2002 to 2024. Shares are against the level the state applies to each contaminant, named in the last column; several are stricter than EPA.

Contaminant	Above state level	Wells tested	State level
Gross alpha	39%	1,391	15 pCi/L
Iron	19%	1,462	300 ug/L
Manganese	14%	1,462	50 ug/L
Total coliform	7%	1,455
PFOA	4%	258	14 ng/L
Nitrate	2%	1,462	10 mg/L
PFOS	2%	258	13 ng/L
PFNA	<1%	258	13 ng/L
E. coli Fecal coliform or	<1%	1,455
Arsenic	0%	561	5 ug/L

What individual samples found

Each row summarizes every public sample for that contaminant inside Winslow township. 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
Radium (226 + 228) 1988 to 2018	11%	70	91%	2	18	5 pCi/L EPA limit
Nitrate 1973 to 2023	0%	113	81%	1.45	9.4	10 mg/L EPA limit
Arsenic 1974 to 2025	0%	74	50%	0.025	1.1	10 ug/L EPA limit
Lead 1974 to 2023	0%	67	66%	0.073	10	15 ug/L EPA limit
Uranium 1988 to 2018	0%	50	66%	0.014	0.564	30 ug/L EPA limit
Sodium 1960 to 2025	no limit	136	100%	6.21	272	20 mg/L health guideline
Manganese 1960 to 2025	no limit	132	97%	15.9	2,500	300 ug/L health guideline
Iron 1960 to 2025	no limit	130	85%	24.9	29,000	300 ug/L nuisance level
Radon 1988 to 2012	no limit	19	95%	220	560	2,000 pCi/L health guideline

Sampled fewer than 10 times, too few to summarize: PFOS (2), PFOA (2), Copper (1), Fluoride (1).

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	0%65 samples	0%26 samples	0%20 samples	n/a
Arsenic	0%24 samples	0%25 samples	0%20 samples	n/a
Radium (226 + 228)	9%34 samples	n/a	16%32 samples	n/a
Lead	0%27 samples	0%22 samples	0%16 samples	n/a
Uranium	0%16 samples	0%20 samples	0%14 samples	n/a

Radium (226 + 228) above the limit in Winslow township rose from 9% of 34 samples before 2000 to 16% of 32 in the 2010s.

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

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

Among homeowners in Winslow township who sent a sample to the state lab, the health-based limits most often exceeded were total coliform (7% of 1,455 wells), PFOA (4% of 258 wells), and nitrate (2% of 1,462 wells). These are ordinary wells tested by their owners, so the shares are the best available picture of a typical well here, with one caveat: people test more often when they suspect a problem.

Iron and manganese exceed the state's advisory level in a sizable share of wells; these are mostly a taste, staining or diet issue rather than a toxicity one.

What to test for in Winslow township

1
Radium (226 + 228)
11% of 70 local samples were above the limit.
2
Total coliform
7% of 1,455 local wells tested were above the New Jersey limit (any detection).
3
PFOA
4% of 258 local wells tested were above the New Jersey limit.
4
Nitrate
2% of 1,462 local wells tested were above the New Jersey limit.
5
PFOS
2% of 258 local wells tested were above the New Jersey limit.
6
PFNA
<1% of 258 local wells tested were above the New Jersey limit.
7
E. coli
<1% of 1,455 local wells tested were above the New Jersey limit (any detection).
8
Gross alpha
39% of 1,391 local wells tested were above the New Jersey limit.
9
Volatile organic compounds (VOCs)
2 hazardous waste sites on record locally.
10
Metals panel
2 hazardous waste sites on record locally.

Test your Winslow township well for radium (226 + 228), total coliform and PFOA

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 New Jersey: certified labs, state programs and prices.

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

The rock under Winslow township

Northern Atlantic Coastal Plain aquifer system

Semiconsolidated sand. Coastal plain sands like these give steady yields at moderate depth. Salt water and sodium are the usual issues near the coast, and nitrate where the water table is shallow; arsenic and radon from bedrock are less common.

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 New Jersey

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, NJDEP
Certified Laboratories, NJDEP

Contamination sources on record in Winslow township

NJDEP records 2 hazardous waste sites in Winslow township, among 159 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.

2: hazardous waste sitesSolvents, degreasers and metals from industrial sites can travel far in fractured bedrock.
114: registered underground storage tank sitesRegistered tanks are regulated and inspected; they matter most when they are old or near a shallow well.
6: lined landfills and transfer facilities
37: other remediation projects

Treatment that fits the local profile

Total coliform

Inspect and repair the well cap and casing, then shock chlorinate and retest; UV disinfection whole-house; Chlorination system

Gross alpha

Point-of-use reverse osmosis; Water softener (cation exchange) for radium; Anion exchange for uranium

Iron

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

Manganese

Oxidizing filter (greensand, birm) whole-house; Water softener (low levels); Point-of-use reverse osmosis

Radium (226 + 228)

Water softener (cation exchange); Point-of-use reverse osmosis

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 total coliform

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 gross alpha

Under-sink reverse osmosis system

under-sink or countertop, about $300

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

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 Winslow township

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

Common questions

Is there arsenic in well water in Winslow township?

Arsenic was detected in 50% of 74 public well samples in Winslow township, 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 high is radon in well water in Winslow township?

The median radon level across 19 public samples in Winslow township was 220 pCi/L, with a high of 560 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.

How often should I test a private well in Winslow township?

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 Winslow township

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 New Jersey dataset as CSV, every county and town, with the sources named.

Sources

USGS Water Quality Portal: 797 samples in Winslow township. Data from the Water Quality Portal, a service of USGS, EPA and USDA; groundwater samples collected by USGS and cooperators. Retrieved September 3, 2026.
NJDEP Private Well Testing Act summaries: summaries for 10 contaminants in Winslow township, up to 1,462 wells each. Share of private wells exceeding each standard in tests required at sale or lease under the New Jersey Private Well Testing Act, September 2002 to December 2024, published by NJDEP. Tests are untreated water at the time of sale or lease, so every well is counted once per transaction. Municipalities with fewer than ten wells are suppressed. Standards are New Jersey's: arsenic 5 ug/L, PFOA 14 ng/L, PFOS 13 ng/L, PFNA 13 ng/L, manganese and iron secondary standards. Uranium and PFAS were added to the required panel in 2021 and 2020, so their well counts are smaller. Retrieved September 9, 2026.
NJDEP regulated sites: 159 regulated sites located in Winslow township. Known Contaminated Sites, regulated underground storage tank facilities and solid waste landfills from the New Jersey Department of Environmental Protection (NJ-GeoWeb). Retrieved September 9, 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.