Strafford County, New Hampshire
20 ZIP codes · Avg score 70/100 · Grade B · Updated 2026-06-04
Strafford County earns a high water safety grade — 20 ZIP codes tracked, virtually all compliant.
How Strafford County Compares
How Strafford County Compares
Strafford County scores 6 points above the New Hampshire state average (64/100) and 2 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-04
ZIP Code Risk Map
Water Quality Map: Strafford County, New Hampshire
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 11.4 (asthma 10.7%, diabetes 8.6%)
Estimated additional annual cost per homeowner: $1,257, driven primarily by sea_level
Infrastructure: 0.387% avg pipe failure probability, 32% of ZIPs at high risk
60% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
↓ Improving trendEPA violation counts by year across Strafford County water systems. Health-based shown in red, total in blue.
Peak year: 2023 with 8 violations. Past 5 years: 20 total (20 health-based). Health-based violations are declining versus the prior 2-year window.
Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $1,257
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
55,727 housing units in Strafford County
Source: U.S. Census Bureau ACS B25034 (Year Structure Built).
Water Safety Affordability
How much it costs to fix water issues relative to home values in Strafford County
Remediation costs are relatively manageable for most homeowners in Strafford County, representing a small fraction of property value.
Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.
Health Outcomes vs National Average
CDC PLACES data for Strafford County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 5 systems in Strafford County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Profile Apartments | 90 | 71 |
| 2 | Rochester Water Department | 25,000 | 56 |
| 3 | Acorn Terrace | 215 | 56 |
| 4 | Rochester Consecutive Wtr Sys | 171 | 56 |
| 5 | Inn at Secretariat Estates | 54 | 56 |
33 total water systems serve Strafford County.
All ZIP Codes in Strafford County
20 ZIP codes tracked in Strafford County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 3821 | Dover | 83 | B | 1 | — |
| 2 | 3822 | Dover | 83 | B | 1 | — |
| 3 | 3839 | Rochester | 81 | B | 14 (2 health) | $300K |
| 4 | 3866 | Rochester | 81 | B | 14 (2 health) | — |
| 5 | 3868 | Rochester | 81 | B | 14 (2 health) | $259K |
| 6 | 3820 | Dover | 78 | B | 1 | $398K |
| 7 | 3824 | Durham | 78 | B | 1 | $470K |
| 8 | 3867 | Rochester | 76 | B | 14 (2 health) | $259K |
| 9 | 3835 | Farmington | 75 | B | 0 | $273K |
| 10 | 3884 | Strafford | 74 | B | 2 | $402K |
| 11 | 3825 | Barrington | 73 | B | 1 | $350K |
| 12 | 3855 | New Durham | 73 | B | 21 (2 health) | $307K |
| 13 | 3861 | Lee | 71 | B | 2 (1 health) | $449K |
| 14 | 3878 | Somersworth | 71 | B | 2 (1 health) | $295K |
| 15 | 3851 | Milton | 69 | C | 2 | $283K |
| 16 | 3887 | Union | 63 | C | 0 | $261K |
| 17 | 3291 | West Nottingham | 53 | D | 0 | — |
| 18 | 3815 | Center Strafford | 53 | D | 0 | — |
| 19 | 3823 | Madbury | 46 | D | 15 (3 health) | $459K |
| 20 | 3869 | Rollinsford | 40 | D | 3 (2 health) | $363K |
Recommended Buyer Guides for Strafford County
Below: editorial picks, no sponsored placements.
- Best Water Filters for Lead — Lead above EPA action level in 2 ZIP codes
- Best Lead Paint Test Kits — 60% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
Deep Dive Reports
Detailed analysis for Strafford County, New Hampshire
Overview
Strafford County in New Hampshire covers 20 ZIP codes with an average Home Safety Score of B (70/100).
16 of 20 ZIP codes have recorded EPA violations. 17 health-based violations have been documented.
← Back to New Hampshire water quality report
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Updated daily.