Iron in New Jersey well water
In New Jersey, 29% of 141,291 private wells tested between 2002 and 2024 had iron above the New Jersey nuisance level (300 ug/L), according to NJDEP.
Iron is a nuisance rather than a health hazard: rust stains, metallic taste, and clogged fixtures above 300 ug/L. It often occurs with manganese and can feed iron bacteria that foul plumbing.
Check your iron number
Type the value from your lab report. It is compared to the New Jersey nuisance level and the EPA limit, the same way the full interpretation does it.
Getting it fixed
Book a free in-home water test with a licensed local company, or see the treatment guide for what removes iron.
By county, from homeowner tests
Share of private wells above the state guidance level (300 ug/L) in tests homeowners sent to the state lab, 2002 to 2024.
| County | Wells tested | Above state level | Highest | |
|---|---|---|---|---|
| Monmouth | 7,582 | 74% | ||
| Salem | 5,093 | 45% | ||
| Burlington | 12,189 | 42% | ||
| Cape May | 7,348 | 42% | ||
| Gloucester | 9,220 | 36% | ||
| Middlesex | 1,222 | 35% | ||
| Ocean | 9,095 | 27% | ||
| Cumberland | 8,423 | 27% | ||
| Passaic | 5,838 | 26% | ||
| Morris | 13,112 | 25% | ||
| Sussex | 14,793 | 24% | ||
| Atlantic | 8,102 | 24% | ||
| Camden | 3,759 | 23% | ||
| Mercer | 3,470 | 21% | ||
| Warren | 7,035 | 20% |
Towns with the highest share above the state level
- Old Bridge township, Middlesex County95% of 41 wells
- Eastampton township, Burlington County95% of 58 wells
- Monroe township, Middlesex County94% of 242 wells
- Moorestown township, Burlington County94% of 82 wells
- Mansfield township, Burlington County91% of 555 wells
- Manalapan township, Monmouth County91% of 702 wells
- Florence township, Burlington County90% of 157 wells
- Middletown township, Monmouth County87% of 63 wells
- Upper Freehold township, Monmouth County86% of 923 wells
- Springfield township, Burlington County86% of 513 wells
- Westampton township, Burlington County85% of 89 wells
- Millstone township, Monmouth County84% of 1,608 wells
- Chesterfield township, Burlington County84% of 281 wells
- Marlboro township, Monmouth County84% of 267 wells
- Colts Neck township, Monmouth County83% of 1,420 wells
- Lumberton township, Burlington County81% of 227 wells
- Woolwich township, Gloucester County80% of 1,056 wells
- Hamilton township, Mercer County80% of 196 wells
- Pilesgrove township, Salem County79% of 771 wells
- Hainesport township, Burlington County79% of 62 wells
- Elsinboro township, Salem County79% of 267 wells
- Mannington township, Salem County76% of 215 wells
- Pennsville township, Salem County74% of 39 wells
- Downe township, Cumberland County74% of 272 wells
- Burlington township, Burlington County72% of 47 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.
- Individual samples from the USGS Water Quality Portal and state monitoring, summarized per geography. iron counts and shares are listed on each county and town page with their sources.