Portsmouth Water Works

ZipCheckup's reading of EPA SDWIS for Portsmouth Water Works (NH1951010): no EPA violations recorded in the last five years. Five years of EPA monitoring have produced no violations for Portsmouth Water Works - the supplier serving 33,000 residents has kept every contaminant level within federal limits, a result that places it among the top-performing utilities for systems with a service population of comparable size.

Data: EPA SDWIS

System Overview

Portsmouth Water Works (EPA ID: NH1951010) is a community water system in New Hampshire that serves approximately 33,000 people from surface water sources.

This system provides water to 5 ZIP codes across 5 communities.

ZIP-Area Home Safety Context: C (66/100)

This is the average Home Safety Score for 3 of 5 service-area ZIP codes with all required score domains observed. It is not a grade for the water utility.

Model 4.0.0 uses SDWIS identity plus accepted ECHO SDWA lifecycle-based water compliance, the UCMR 5 PFAS MCL screen, EPA radon zone, and annual EPA AirData AQI across three equally weighted domains. Missing required evidence suppresses the score.

Violation History

Lead & Copper

EPA Lead and Copper Rule evidence attributed directly to this water system:

No copper action-level exceedance record appears for this PWSID in the accepted LCR snapshot. This does not establish a clean copper measurement.

Radon Risk in Service Area

Dominant radon zone for ZIP codes served by this system: Zone 2 (Moderate Risk)

The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.

ZIP Codes Served

Coverage: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by NH or modeled from parcel and building-footprint data.

• 03801 - Portsmouth
• 03820 - Dover
• 03840 - Greenland
• 03854 - New Castle
• 03870 - Rye

Data Sources

This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Portsmouth Water Works (NH1951010) on EPA.gov.

Frequently Asked Questions

Is Portsmouth Water Works water safe to drink?

The accepted 2026Q2 ECHO snapshot contains zero violation records for Portsmouth Water Works in the inclusive 2021-2026 record-year window. This is a compliance-record finding, not a guarantee about water at a specific tap.

How many people does Portsmouth Water Works serve?

Portsmouth Water Works serves approximately 33,000 people across 5 ZIP codes in New Hampshire.

Where does Portsmouth Water Works get its water?

The primary water source is surface water.

@misc{zipcheckup-water-system-nh1951010,
  author = {{ZipCheckup}},
  title  = {{Portsmouth Water Works, NH: Serves 33K People}},
  year   = {n.d.},
  url    = {https://zipcheckup.com/water-system/nh1951010/}
}