Water Quality: Portsmouth, NH
10 water systems • 44,419 people served
Multiple Health ViolationsWater Quality Summary
Portsmouth is served by 10 public water systems with a combined service population of 44,419 people, and has 68 EPA Safe Drinking Water Act violations on record. Critically, 17 of those are health-based violations, meaning one or more contaminants were detected above EPA-established safe levels — a serious public health concern. Portsmouth's violation count is 64% above the national average for New Hampshire. Contaminants associated with violations include Chlorine Dioxide, Disinfection Byproducts, E. coli, TTHM.
Contaminants Found
Can cause anemia in infants and young children; may cause nervous system effects at high levels.
Common source: Water treatment disinfectant used to control taste, odor, and microorganisms
EPA limit: 0.8 mg/L
Broad category of chemicals formed during disinfection, associated with increased cancer risk and adverse reproductive effects.
Common source: Reaction of disinfectants (chlorine, ozone, chloramines) with organic matter
Causes gastrointestinal illness; certain strains (e.g., O157:H7) can cause severe kidney failure and death.
Common source: Fecal contamination from humans or animals entering the water supply
EPA limit: Zero (no E. coli permitted in drinking water)
Total trihalomethanes are linked to increased risk of bladder cancer and adverse reproductive outcomes.
Common source: Reaction of chlorine disinfectants with naturally occurring organic matter in water
EPA limit: 0.080 mg/L (80 ppb)
Water Systems Serving Portsmouth
| System Name | PWSID | Source | Population | Violations |
|---|---|---|---|---|
| PORTSMOUTH WATER WORKS | NH1951010 | Surface Water | 33,000 | 0 |
| PEASE TRADE PORT | NH1951020 | Groundwater | 9,900 | 0 |
| NEW CASTLE WATER WORKS | NH1661010 | Surface Water | 910 | 16 |
| HEMLOCK HAVEN | NH1053020 | Groundwater | 207 | 3 |
| PIPER MEADOWS PRIVATE COMMUNTY | NH0023010 | Groundwater | 125 | 17 |
| CEDAR CREEK | NH0512200 | Groundwater | 105 | 18 |
| FOUR SEASONS MOBILE HOME PARK | NH1053010 | Groundwater | 55 | 2 |
| HIGH PASTURES AT BLACK MTN | NH1212090 | Groundwater | 47 | 1 |
| BLUEBERRY VILLAGE CONDOS | NH0162180 | Groundwater | 40 | 3 |
| CEDAR WOOD ESTATES | NH1332040 | Groundwater | 30 | 8 |
Concerned About Your Water?
A home water filter can remove common contaminants. NSF-certified filters are tested against EPA standards.
Consider a reverse osmosis system for comprehensive filtration or a carbon filter for basic improvement.
Other Cities in New Hampshire
Data Sources
Drinking water violation data from the EPA Safe Drinking Water Information System (SDWIS). Data includes all recorded violations for active community water systems.