Lopatcong, NJ tap water quality

The utility that serves Lopatcong reported no detections of the PFAS it tested for in 2025.

Lopatcong, in Warren County, has about 9,537 residents. About 82% of them live inside the service area of Aqua New Jersey's Phillipsburg system, according to New Jersey DEP's service area map.

Hardness and lead in Lopatcong's water

Hardness

154 mg/L9 grains per gallon, hardThe utility's report lists one value for hardness, 154 mg/L (2025).New Jersey's recommended upper limit 250 mg/L (for taste and appearance; not enforceable); no federal limit.

Lead, 90th percentile of home taps

1.3 ppbAction level: 15 ppb, dropping to 10 ppb in November 2027

9 grains per gallon in Lopatcong's report: size a water softener for Lopatcong. See how hard the water is elsewhere in New Jersey.

Filtering Lopatcong's tap water at home

The utility didn't detect the PFAS it tested for. If you're concerned about lead from your home's pipes, look for a filter certified to NSF/ANSI Standard 53 for lead.

Where does Lopatcong's water come from?

The Phillipsburg system's 2025 report lists its own sources as 3 deep wells in various geologic formations.

Bills, new service and account questions are handled by Aqua New Jersey, which runs the Phillipsburg system: customer service and billing.

Local factors in Lopatcong

Age of homes

50% (margin of error ±9 percentage points) of homes in Lopatcong were built before 1980 (Warren County: 60%, New Jersey: 63%; U.S. Census ACS 2020-2024). The utility's water quality report describes water leaving the system, not the plumbing inside a home; why the build year matters for lead.

Source: U.S. Census Bureau, American Community Survey 2020-2024 5-year estimates, table B25034 (Year Structure Built).

Radon

NJDEP places Lopatcong in Radon Tier 1 (high potential: 25 percent or more of tested homes at or above 4 picocuries per liter) based on indoor radon tests (2015). In that report, 37% of the 1,354 homes tested in Lopatcong were at or above 4 picocuries per liter. NJDEP recommends testing every home regardless of tier. Homes on private wells can also get radon from well water. How radon tiers work.

Source: New Jersey DEP Radon Section, 2015 Radon Tier Assignment Report; the same figures appear in NJDEP's current municipal tier list.

Known contaminated sites

NJDEP lists 4 sites in Lopatcong where soil or groundwater contamination has been confirmed (October 14, 2026). These are places under cleanup oversight; they do not mean that tap water from the public system is contaminated. The public water system is tested and treated separately; people with private wells near a listed site can ask the county health department about testing.

Source: New Jersey DEP, Known Contaminated Sites List map layer, retrieved October 16, 2026, with site-by-site lists in NJDEP's Known Contaminated Sites reports.

Water and sewer bills

In the Census Bureau's survey (ACS 2020-2024, about this question), 75% (margin of error ±6 percentage points) of occupied homes in Lopatcong pay a separate charge for water and sewer; the rest report no charge or a charge included in other fees, such as rent. Among the homes that pay, 22% (margin of error ±6 percentage points) report $1,000 or more for the year (26% in Warren County, 30% statewide), as households report it rather than as the utility bills it.

Source: U.S. Census Bureau, American Community Survey 2020-2024 5-year estimates, table B25134 (Annual Water and Sewer Costs).

ZIP codes covering Lopatcong: 08865 (shared with Harmony, Pohatcong, Phillipsburg), 08886 (shared with Greenwich Township, Franklin Township). Source: U.S. Census Bureau 2020 ZIP Code Tabulation Areas.