Cornerstone Estates
EPA ID: NH2082060 · 202 people served · 1 ZIP code
Cornerstone Estates earns a clean bill from EPA monitoring — no violations in five years across a service area of 202 people.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Cornerstone Estates Source: EPA SDWIS service area boundaries.
Service area boundary — Grade B
Service Area Demographics
The Cornerstone Estates serves a community with a median household income of $137,813 and an estimated 6,590 residents across its service area. Approximately 55% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
Cornerstone Estates'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
Cornerstone Estates (EPA ID: NH2082060) is a community water system in New Hampshire that serves approximately 202 people from groundwater sources.
This system serves ZIP code 03873 in Sandown.
Average Home Safety Score: B (75/100)
Based on water quality violations, lead levels, and radon risk across all ZIP codes served by this system.
Violation History
Lead & Copper
No Lead and Copper Rule sampling data available for this water system.
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.
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
- 03873 — Sandown
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Cornerstone Estates (NH2082060) on EPA.gov.
Frequently Asked Questions
Is Cornerstone Estates water safe to drink?
Based on EPA records, Cornerstone Estates has no recorded violations in the past 5 years — a positive indicator of water quality management.
How many people does Cornerstone Estates serve?
Cornerstone Estates serves approximately 202 people across 1 ZIP code in New Hampshire.
Where does Cornerstone Estates get its water?
The primary water source is groundwater.