B65/100
Portsmouth Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 42,900 residents · New Hampshire
What's In Portsmouth's Tap Water?
70
Contaminants Tested
1
Exceed EPA Limits
0
Above EPA Goals
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 1.43 mg/L | 1.30 mg/L | Over Limit |
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2014.
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Water Utility Details
PORTSMOUTH WATER WORKS
Population Served
33,000
Water Source
Surface Water
System ID
NH1951010
PEASE TRADE PORT
Population Served
9,900
Water Source
Groundwater
System ID
NH1951020
Frequently Asked Questions About Portsmouth Water
Is Portsmouth tap water safe to drink?
Portsmouth, New Hampshire tap water receives a grade of B (65/100), which is considered good. Out of 70 contaminants tested, 1 exceed EPA maximum contaminant levels (MCLs) and 1 exceed health guidelines (MCLGs). While the water meets federal standards, some residents may still choose to use a filter for additional peace of mind.
What contaminants are in Portsmouth's water?
Of the 70 contaminants tested in Portsmouth's water supply, the most notable include Copper (90th percentile). 1 contaminant(s) exceed EPA legal limits (MCLs). 1 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Portsmouth have any water quality violations?
Yes, Portsmouth has 13 EPA violation(s) on record, with the most recent in 2014. Violation types include MCL, MR, TT. 12 of these are health-based violations, which are the most serious category.
Do I need a water filter in Portsmouth?
Based on EPA data, using a water filter in Portsmouth is recommended. 1 contaminant(s) exceed legal limits. An NSF-certified filter — such as a reverse osmosis or activated carbon system — can effectively reduce many common contaminants. Choose a filter certified to remove the specific contaminants found in your area.
Where does Portsmouth's tap water come from?
Portsmouth's drinking water is sourced from surface water and supplied by PORTSMOUTH WATER WORKS and 1 other water system(s). The system serves approximately 42,900 people. Surface water sources include rivers, lakes, and reservoirs.
How often is Portsmouth's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Portsmouth's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Portsmouth's water compare to other cities in New Hampshire?
Portsmouth's water quality score of 65/100 earns a grade of B, which is considered good. This is an above-average score compared to many cities nationwide. Visit our New Hampshire state page to see how all cities in the state compare.
What should I do if I'm concerned about Portsmouth's water quality?
If you have concerns about Portsmouth's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (PORTSMOUTH WATER WORKS) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.