E. coli in New Jersey well water
In New Jersey, 2% of 140,562 private wells tested between 2002 and 2024 had E. coli above the New Jersey limit (any detection) (n/a MPN/100mL), according to NJDEP.
E. coli in a well means fecal contamination from septic systems, animals or surface water entering the well. It can cause serious gastrointestinal illness. Any detection is a failure.
Check your E. coli number
Type the value from your lab report. It is compared to the EPA limit, the same way the full interpretation does it.
Test your New Jersey well for E. coli
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 $209Already tested? Upload the report
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Systems that remove E. coli
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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.
Rather have it installed and sized for your well? Book a free in-home water test with a licensed local company.
Where to get a well tested for E. coli in New Jersey: certified labs, state programs and prices.
By county, from homeowner tests
Share of private wells above the state guidance level (n/a MPN/100mL) in tests homeowners sent to the state lab, 2002 to 2024.
Towns with the highest share above the state level
- Watchung borough, Somerset County10% of 171 wells
- Millstone borough, Somerset County9% of 32 wells
- Princeton, Mercer County9% of 56 wells
- Mine Hill township, Morris County9% of 56 wells
- Franklin township, Hunterdon County9% of 586 wells
- Lambertville, Hunterdon County7% of 122 wells
- Cherry Hill township, Camden County7% of 30 wells
- Lafayette township, Sussex County7% of 340 wells
- Burlington township, Burlington County6% of 47 wells
- South Brunswick township, Middlesex County6% of 96 wells
- Bridgewater township, Somerset County6% of 1,430 wells
- Frelinghuysen township, Warren County6% of 359 wells
- Mount Arlington borough, Morris County6% of 132 wells
- Branchburg township, Somerset County6% of 711 wells
- Pohatcong township, Warren County6% of 211 wells
- Woodland Park borough, Passaic County6% of 53 wells
- Califon borough, Hunterdon County5% of 37 wells
- South Bound Brook borough, Somerset County5% of 38 wells
- Bloomingdale borough, Passaic County5% of 254 wells
- Lincoln Park borough, Morris County5% of 59 wells
- Green township, Sussex County5% of 584 wells
- Hampton township, Sussex County5% of 769 wells
- Warren township, Somerset County5% of 612 wells
- Readington township, Hunterdon County5% of 2,060 wells
- Wantage township, Sussex County4% of 1,572 wells
Sources
- NJDEP Private Well Testing Act summaries: 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.