New Hampshire
Water quality data from the EPA Safe Drinking Water Information System
Water Systems
4,131
Active public water systems
Population Served
1.17M
Residents with piped water
Lead Violations
482
Systems exceeding 15 ppb
Copper Violations
224
Lead & Copper Rule
Average Lead Level
EPA Action Level: 15 ppb
MCLG (health goal): 0 ppb
Average across 554 systems with reported lead data.
Violations Detected
706 water systems in New Hampshire have reported violations under the Lead and Copper Rule. These utilities are required to notify customers and take corrective action.
Water Systems: Highest Lead Levels
| System Name | City | Population | Lead Level | Status | Sample Date |
|---|---|---|---|---|---|
| LAKEPORT | 21,000 | 4.00 ppb | OK | 2023-12-31 | |
| SEABROOK | 14,000 | 3.00 ppb | OK | 2024-12-31 | |
| ROCHESTER | 25,000 | 2.00 ppb | OK | 2023-12-31 | |
| SALEM | 21,000 | 2.00 ppb | OK | 2024-12-31 | |
| CONCORD | 44,215 | 1.00 ppb | OK | 2023-12-31 | |
| DOVER | 29,000 | 1.00 ppb | OK | 2024-12-31 | |
| MANCHESTER | 123,500 | 0.00 ppb | OK | 2024-06-30 | |
| NASHUA | 89,073 | 0.00 ppb | OK | 2023-12-31 | |
| PORTSMOUTH | 33,000 | 0.00 ppb | OK | 2024-12-31 | |
| KEENE | 30,000 | 0.00 ppb | OK | 2024-12-31 | |
| MERRIMACK | 25,500 | 0.00 ppb | OK | 2024-06-30 | |
| DERRY | 17,210 | 0.00 ppb | OK | 2023-12-31 | |
| HUDSON | 16,700 | 0.00 ppb | OK | 2024-12-31 | |
| DURHAM | 16,000 | 0.00 ppb | OK | 2024-12-31 | |
| EXETER | 12,236 | 0.00 ppb | OK | 2024-12-31 |
Showing top 15 of 527 systems with lead data. Action level: 15 ppb.
Systems With Active Violations
These water systems have exceeded EPA limits and must take corrective action.
PORTSMOUTH · Pop. 33,000
Lead: 0.00 ppb (2024-12-31)
KEENE · Pop. 30,000
Lead: 0.00 ppb (2024-12-31)
HUDSON · Pop. 16,700
Lead: 0.00 ppb (2024-12-31)
SEABROOK · Pop. 14,000
Lead: 3.00 ppb (2024-12-31)
Water Source Types
Air Quality
GoodAvg AQI
38.8
PM2.5
5.2 µg/m³
Unhealthy Days
1
Primary Pollutant
Ozone
Source: EPA AirNow & American Lung Association 2024 State of the Air. AQI scale: 0–50 Good · 51–100 Moderate · 101–150 Sensitive Groups · 151+ Unhealthy.
PFAS Contamination
High DetectionPFAS (per- and polyfluoroalkyl substances), known as “forever chemicals,” are a group of synthetic chemicals that persist indefinitely in the environment and human body. The EPA set a maximum contaminant level (MCL) of 4 parts per trillion (ppt) for PFOA and PFOS in April 2024. View national PFAS tracker →
Systems Tested
248
PFAS Detected
202
Detection Rate
81.5%
Exceeding MCL (4 ppt)
68(27.4%)
Highest recorded level: 185 ppt (EPA MCL: 4 ppt). EWG: 202 systems above proposed limits (4th highest nationally). Pease AFB (PFAS from firefighting foam) and Saint-Gobain Merrimack plant are major sources. State has own MCLs