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New Jersey water profile

Nitrate in New Jersey community water systems

New Jersey's nitrate map tells two stories: the agricultural Coastal Plain, where USGS measured some of the highest nitrate in the nation's shallow groundwater, and the fractured-rock northwest, where suburban wells on septic do the reporting. See where the pattern concentrates and what each reporting system measured in the three years from August 9, 2023 to August 9, 2026.

Browse all 548 New Jersey systems →

Search by the utility or system name shown on a water bill. Example: New Jersey American Water. Private wells are not in this inventory.

99%
of the state’s 555 active community water systems have a current result here
548
systems with a current nitrate result
8,795,352
people served by those reporting systems
4.6%
of reporting systems at or above 5 mg/L
How to read these numbers Each system is placed into a band by its most recent reported result within a rolling three-year window. The bands describe how strongly human activity, read from nitrate, has marked a water source; they are not a safety verdict. Figures describe system reporting, not nitrate measured at an individual tap.

How New Jersey's systems fall across the five bands

Most systems report below 3 mg/L

Natural background
0.00–0.99 mg/L as N
309 systems · 5,597,764 served
Human impact likely
1.00–2.99 mg/L as N
164 systems · 2,057,463 served
Human impact clear
3.00–4.99 mg/L as N
50 systems · 765,725 served
Health-study range
5.00–9.99 mg/L as N
25 systems · 374,400 served
Above the federal limit
10.00 mg/L and above
0 systems · 0 served

Each system appears in one band only, placed by its most recent reported result in the current three-year window. Counts sit beside people served so a small number of larger systems cannot hide behind a row of tiny ones. Of the 25 systems reporting 5 mg/L or more, 2 stayed at or above 5 across the whole three-year range; the other 23 reached it only on a high sample and otherwise ran lower.

Most recent reading Jun 2026; the typical system was last tested around Feb 2026. 478 systems sampled their own water; 70 systems carry a supplier’s result.

The named systems

Every reading here belongs to a utility with a name

Highest recent readings
SystemMost recent resultBandBased onPeople served
Veolia Water New Jersey East Brookwood9.14 mg/LApr 2026a high point — runs lowerHealth-study range24 samples612
Bayshore Mobile Home Park8.80 mg/LApr 2026a high point — runs lowerHealth-study range11 samples81
Bridgeton City Water Dept8.20 mg/LJan 2026a high point — runs lowerHealth-study range12 samples22,770
Big Oak Rehab7.84 mg/LJun 2026a high point — runs lowerHealth-study range16 samples259
North Shore Water Association7.15 mg/LApr 2026Health-study range5 samples105
Veolia Water Nj Independence Valley View6.95 mg/LApr 2026a high point — runs lowerHealth-study range12 samples110
Upper Deerfield Twp Water Dept6.68 mg/LApr 2026a high point — runs lowerHealth-study range14 samples3,100
Village I6.64 mg/LMay 2026Health-study range10 samples43
Largest systems
SystemMost recent resultBandBased onPeople served
Veolia Water New Jersey Hackensack0.10 mg/LJun 2026Natural background150 samples792,713
Nj American Water - Raritan0.78 mg/LApr 2026Natural background38 samples615,430
Nj American Water - Coastal North0.04 mg/LJun 2026Natural background45 samples377,613
Passaic Valley Water Commission1.48 mg/LJun 2026Human impact likely35 samples310,483
Newark Water Department0.05 mg/LNov 2025Natural background3 samples294,274

Each result shows its date and what it rests on, so a lone sample is never taken for a settled measurement. A single high sample is not a complete account of what a household drinks.

Where higher nitrate concentrates

Two settings: Coastal Plain farms, Highlands sprawl

Human impact is clear on drinking water served in 16 of New Jersey’s 21 counties. Each is shaded by how many of its systems reported 3.00 mg/L as N or above. Shading counts systems, not severity — a county with many small utilities can outrank one holding a single larger system that reads higher. The table beside the map splits the two bands so that difference stays visible.

NJ counties shaded by number of community water systems reporting nitrate at or above 3.00 mg/L as NCounties are shaded by how many community water systems reported nitrate at or above 3.00 mg/L as N in the three years from August 9, 2023 to August 9, 2026. The same counts appear in the table below this map.Cumberland County — 3 systems at 3.00–4.99 mg/L as N; 5 systems at 5.00 mg/L as N or aboveHunterdon County — 6 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveWarren County — 5 systems at 3.00–4.99 mg/L as N; 3 systems at 5.00 mg/L as N or aboveOcean County — 1 system at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveBergen County — 3 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveMiddlesex County — 6 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveAtlantic County — 1 system at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveBurlington County — 1 system at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveEssex County — 0 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveMercer County — 3 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveSussex County — 10 systems at 3.00–4.99 mg/L as N; 6 systems at 5.00 mg/L as N or aboveMorris County — 5 systems at 3.00–4.99 mg/L as N; 3 systems at 5.00 mg/L as N or aboveCamden County — 2 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveSalem County — 0 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveGloucester County — 3 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or abovePassaic County — 1 system at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or above
none1–23–56–1112–2526+Number of drinking water systems reporting ≥3.00 mg/L NO₃–N per county as of August 9, 2026

Sussex leads this layer with 6 reporting systems, followed by Cumberland, Morris, Warren. Two settings: Coastal Plain farms, Highlands sprawl.

Counties with the most systems at or above 3 mg/L as N
County3–4.99≥5Total ≥3
Sussex10616
Cumberland358
Morris538
Warren538
Hunterdon606

Counts use each system's most recent reported result in the current three-year window. A system appears in only one of the two bands.

Find a specific New Jersey system

What the statewide pattern says

A documented agricultural hotspot, and a second suburban setting

New Jersey's Coastal Plain nitrate is among the best-documented agricultural signals in the country; the northwest's fractured-rock counties add a septic-and-sprawl setting that is studied less but reported clearly.

The Coastal Plain story is unusually well measured. Sampling 230 shallow wells across the Kirkwood-Cohansey and Potomac-Raritan-Magothy outcrops, USGS found nitrate above the 10 mg/L federal limit in more than a third of wells in agricultural areas, with concentration rising almost one-to-one with the share of farmed land within 800 meters (r = 0.81). Isotope ratios pointed to chemical fertilizer, not livestock or septic, in those farmed areas (Vowinkel and Tapper, 1995).

The trend runs the wrong direction and takes decades to unwind. Modeling the Kirkwood-Cohansey near Glassboro, USGS estimated that nitrate in aquifer recharge rose from a background of about 0.07 mg/L in 1940 to 2.5–14 mg/L by 1990; even if inputs stopped, elevated concentrations would persist in streams and wells for decades because of travel time, though roughly 40 percent of the nitrogen is removed by denitrification near streams (Kauffman and others, 2001). Cumberland County, one of the highlighted counties on this page, sits in that Coastal Plain farm belt.

The second setting is the northwest — Sussex, Warren, Hunterdon and Morris — fractured-rock Highlands and Ridge-and-Valley terrain where suburban development runs on individual wells and septic systems. The nitrate literature there is thinner than on the Coastal Plain, so this page does not claim a certified source for those counties; the public-system readings mark the signal, and the plumbing — dense septic on fractured rock — supplies the plausible pathway (Nolan and Hitt, 2006).

The supported source reading is agricultural fertilizer on the Coastal Plain; mixed septic and lawn nitrogen in the fractured-rock northwest — not a certified source at any individual system. Later work on nitrogen moving toward Barnegat Bay keeps both readings in play (Voronin and Cauller, 2017).

The general science — how nitrate moves, why some ground is vulnerable, and why the legacy lingers — is laid out with its sources on Where nitrate comes from.

Questions this page answers

What the New Jersey pattern does—and does not—say

Where does nitrate concentrate in New Jersey community water systems?

Sussex leads this layer with 6 reporting systems, followed by Cumberland, Morris, Warren. Two settings: Coastal Plain farms, Highlands sprawl.

Why is New Jersey's Coastal Plain a national reference case for nitrate?

Because USGS measured it directly: more than a third of shallow agricultural-area wells exceeded the federal limit, concentration tracked the share of farmed land within 800 meters almost one-to-one, and isotope ratios identified chemical fertilizer as the predominant source.

If fertilizer use fell, would Coastal Plain nitrate fall quickly?

No. USGS modeling of the Kirkwood-Cohansey found groundwater travel time creates a lag of decades: even with an immediate stop to nitrogen inputs, elevated nitrate would persist in wells and streams for years, and with gradual reductions concentrations keep rising for a time before falling.

Does a high public-system result mean a nearby private well is high?

No. It is a local sentinel, not a well-specific result. It shows that nitrogen and a transport pathway have reached groundwater in the area; a certified-lab test is still the only way to know a specific private well.

Sources and provenance

What this page rests on

  1. NitrateSmart inventory: 548 New Jersey community water systems with a current nitrate result in the three years from August 9, 2023 to August 9, 2026. Figures count people served by reporting systems, not measured tap exposure.
  2. Nolan BT, Hitt KJ (2006). Vulnerability of Shallow Groundwater and Drinking-Water Wells to Nitrate in the United States. Environmental Science & Technology 40(24):7834–7840.
  3. Dubrovsky NM, and others (2010). Nutrients in the Nation's Streams and Groundwater, 1992–2004. USGS Circular 1350.
  4. Vowinkel EF, Tapper RJ (1995). Indicators of the sources and distribution of nitrate in water from shallow domestic wells in agricultural areas of the New Jersey Coastal Plain. USGS Water-Resources Investigations Report 93-4178 — >33% of agricultural-area wells above the MCL; isotopes point to chemical fertilizer.
  5. Kauffman LJ, Baehr AL, Ayers MA, Stackelberg PE (2001). Effects of land use and travel time on the distribution of nitrate in the Kirkwood-Cohansey aquifer system in southern New Jersey. USGS Water-Resources Investigations Report 2001-4117 — recharge nitrate rose from 0.07 mg/L (1940) to 2.5–14 mg/L (1990); ~40% removed by denitrification near streams.
  6. Voronin LM, Cauller SJ (2017). Simulation of nitrogen transport in the Barnegat Bay watershed, New Jersey. USGS Scientific Investigations Report 2016-5169.