Monmouth County, New Jersey: drinking water report. Monmouth County sits along the New Jersey Shore, home to about 640,000 residents.
Monmouth County sits along the New Jersey Shore, home to about 640,000 residents. Water comes from a mix of groundwater and surface water, with New Jersey American Water serving the largest share of customers. The county's aquifers – primarily the Kirkwood-Cohansey and deeper formations – are the backbone of the supply, supplemented by the Swimming River Reservoir and Manasquan Reservoir for surface water.
New Jersey has adopted some of the strictest PFAS standards in the nation: 14 ppt for PFOA, 13 ppt for PFOS, and 13 ppt for PFNA. These limits have forced aggressive testing and treatment across Monmouth County's water systems. UCMR5 data shows PFAS detections in over a dozen county systems, with some exceeding state MCLs.
According to the New Jersey Department of Environmental Protection's 2024 compliance data, five Monmouth County water systems installed or upgraded PFAS treatment facilities to meet state standards. The former Fort Monmouth military installation, which closed in 2011, is a documented PFAS source with ongoing remediation.
New Jersey's strict standards mean your utility is likely already treating for PFAS if detections are significant. But household-level filtration adds another layer of protection.
Check your water to see data for your specific provider. Our water filter guide covers which filters complement utility-level treatment. Pull your detailed report, and visit our New Jersey page for statewide data.
Drinking water is one exposure route. These federal datasets also cover Monmouth County, NJ.
The EPA places Monmouth County, NJ in Zone 1 - the EPA's highest-risk category, where the predicted average indoor radon level is above 4 pCi/L. Zone maps predict an area's radon potential from geology and existing indoor readings; they say nothing about a specific house. Testing is the only way to know your own level.
58% of homes in Monmouth County, NJ were built before 1980, and 18% before 1950. Residential lead paint was banned in 1978, so housing age is the strongest available proxy for lead-paint exposure. This describes the county's housing stock, not any one home.
Modelled annual fine-particle pollution (PM2.5) in Monmouth County, NJ averages 7 µg/m³, within the EPA's annual standard of 9 µg/m³. These are CDC modelled county estimates rather than readings from a specific monitor.
How radon zones work · Air quality by county · Lead exposure guide
Across 53 public water systems serving Monmouth County, NJ with EPA lead testing on record, 2 (3.8%) reported a 90th-percentile lead result above the EPA's 15 ppb action level, and the median is 2 ppb. 18 water systems serving Monmouth County, NJ carry a health-based EPA Safe Drinking Water Act violation.
| Most-cited violation type | Systems affected |
|---|---|
| Lead and Copper Rule | 8 |
| Total Trihalomethanes (TTHM) | 2 |
| Revised Total Coliform Rule | 2 |
| Gross Alpha (excl. radon & uranium) | 1 |
| Surface Water Treatment Rule | 1 |
Source: EPA Lead and Copper Rule 90th-percentile tap sampling and EPA SDWIS Safe Drinking Water Act enforcement records, aggregated from the public water systems serving this county. Figures are counts of water systems, not a test of any individual home or tap.