Great Bay Water System
EPA ID: NH1732030 · 218 people served · 1 ZIP code
Five years of EPA monitoring have produced no violations for Great Bay Water System — the supplier serving 218 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 Last verified: 2026-04-02
Service Area Map
Coverage area for Great Bay Water System Source: EPA SDWIS service area boundaries.
Service area boundary
Service Area Demographics
The Great Bay Water System serves a community with a median household income of $94,345 and an estimated 9,431 residents across its service area. Approximately 59% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
Great Bay Water System's water is pumped from underground aquifers. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
About 1% of homes in Rockingham County, New Hampshire rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Superfund Proximity Note: This service area ranks in the 80th percentile nationally for proximity to Superfund (NPL) sites. Groundwater sources near contaminated sites may face elevated risk from industrial chemicals.
Infrastructure Risk
Comparable Water Systems
Similar-sized systems in New Hampshire
Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
Great Bay Water System (EPA ID: NH1732030) is a community water system in New Hampshire that serves approximately 218 people from groundwater sources.
This system serves ZIP code 03857 in Newmarket.
Violation History
Lead & Copper
No Lead and Copper Rule sampling data available for this water system.
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
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.
- 03857 — Newmarket
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Great Bay Water System (NH1732030) on EPA.gov.
Frequently Asked Questions
Is Great Bay Water System water safe to drink?
Based on EPA records, Great Bay Water System has no recorded violations in the past 5 years — a positive indicator of water quality management.
How many people does Great Bay Water System serve?
Great Bay Water System serves approximately 218 people across 1 ZIP code in New Hampshire.
Where does Great Bay Water System get its water?
The primary water source is groundwater.