Rockingham County in southeastern New Hampshire has a population of about 315,000, making it the state's most populous county.
Rockingham County in southeastern New Hampshire has a population of about 315,000, making it the state's most populous county. Communities from Salem to Portsmouth rely on a mix of surface water and groundwater. Pease International Tradeport – the former Pease Air Force Base – in Portsmouth became one of the first PFAS contamination cases to gain national attention and has shaped New Hampshire's aggressive regulatory response.
Pease AFB's PFAS contamination was identified in 2014, making it one of the earliest documented cases of military PFAS in drinking water. According to the New Hampshire DES's 2024 environmental fact sheet, PFOS was detected in the Haven well at Pease at concentrations exceeding 2,100 ppt before the well was shut down. The contamination affected the on-site daycare, businesses, and surrounding residential areas.
New Hampshire subsequently adopted some of the strictest PFAS standards in the country: 12 ppt for PFOA, 15 ppt for PFOS, with additional limits for PFHxS and PFNA. According to NHDES's 2024 statewide PFAS report, eight public water systems in Rockingham County have detected PFAS above state MCLs, requiring treatment. The Pease case also prompted the CDC/ATSDR to conduct a health study of affected residents.
Rockingham County has been at the leading edge of PFAS awareness and response. If you are near Pease or in one of the affected communities, your water system has likely already installed treatment. Household filtration adds another layer.
Check your water for current data on your system. For PFAS, reverse osmosis or activated carbon filters certified to NSF P473 are effective. Our water filter guide details the options. Pull your detailed report for historical context, and visit our New Hampshire page for statewide data.
Drinking water is one exposure route. These federal datasets also cover Rockingham County, NH.
The EPA places Rockingham County, NH in Zone 2 - a moderate-risk category, with a predicted average indoor radon level between 2 and 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.
47% of homes in Rockingham County, NH were built before 1980, and 17% 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 Rockingham County, NH averages 5.8 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
27 public water systems serving Rockingham County, NH have EPA lead testing on record. The reported lead sample skews toward systems that already flagged a problem, so its exceedance rate is not directly comparable with other areas. 75 water systems serving Rockingham County, NH carry a health-based EPA Safe Drinking Water Act violation.
| Most-cited violation type | Systems affected |
|---|---|
| Ground Water Rule | 24 |
| Arsenic | 22 |
| Revised Total Coliform Rule | 18 |
| Lead and Copper Rule | 16 |
| Combined Radium (226 + 228) | 5 |
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.