Grafton County, New Hampshire
39 ZIP codes · Avg score 65/100 · Grade C · Updated 2026-06-04
Compared to top-scoring counties, Grafton County's 39 ZIP codes land in the middle tier — some meet standards cleanly, others carry documented violations, and the gap between the best and worst areas is wider than average.
How Grafton County Compares
How Grafton County Compares
Grafton County scores 1 points above the New Hampshire state average (64/100) and 3 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-04
ZIP Code Risk Map
Water Quality Map: Grafton 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: 11.5 (asthma 10.4%, diabetes 9.4%)
Estimated additional annual cost per homeowner: $1,290, driven primarily by energy_code_gap
Infrastructure: 0.411% avg pipe failure probability, 46% of ZIPs at high risk
65% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
→ Stable trendEPA violation counts by year across Grafton County water systems. Health-based shown in red, total in blue.
Peak year: 2025 with 10 violations. Past 5 years: 31 total (31 health-based).
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: $1,290
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
51,559 housing units in Grafton 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 Grafton County
Remediation costs are relatively manageable for most homeowners in Grafton 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 Grafton 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 Grafton County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Glencliff Improvement | 30 | 23 |
| 2 | CANAAN WATER DEPT | 684 | 14 |
| 3 | Cardigan Mountain Sch | 300 | 14 |
| 4 | Mascoma Valley Coop | 73 | 14 |
| 5 | Country Village Mhp | 66 | 14 |
66 total water systems serve Grafton County.
All ZIP Codes in Grafton County
39 ZIP codes tracked in Grafton County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 3755 | Hanover | 83 | B | 0 | $744K |
| 2 | 3251 | Lincoln | 78 | B | 1 | $312K |
| 3 | 3756 | Lebanon | 78 | B | 2 (1 health) | — |
| 4 | 3771 | Monroe | 78 | B | 9 (4 health) | $257K |
| 5 | 3264 | Plymouth | 77 | B | 2 (1 health) | $273K |
| 6 | 3241 | Hebron | 75 | B | 0 | $402K |
| 7 | 3293 | Woodstock | 75 | B | 0 | $450K |
| 8 | 3561 | Littleton | 75 | B | 1 (1 health) | $249K |
| 9 | 3740 | Bath | 75 | B | 1 | $219K |
| 10 | 3777 | Orford | 75 | B | 0 | $262K |
| 11 | 3785 | Woodsville | 75 | B | 1 | $196K |
| 12 | 3279 | Warren | 74 | B | 11 (1 health) | $239K |
| 13 | 3766 | Lebanon | 74 | B | 2 (1 health) | $348K |
| 14 | 3222 | Bristol | 73 | B | 0 | $257K |
| 15 | 3765 | Haverhill | 73 | B | 4 | $296K |
| 16 | 3215 | Waterville Valley | 72 | B | 1 | $377K |
| 17 | 3774 | North Haverhill | 71 | B | 3 | $189K |
| 18 | 3217 | Ashland | 70 | B | 1 | $189K |
| 19 | 3262 | North Woodstock | 70 | B | 0 | $306K |
| 20 | 3748 | Enfield | 70 | B | 8 (2 health) | $339K |
| 21 | 3585 | Lisbon | 69 | C | 2 | $215K |
| 22 | 3586 | Sugar Hill | 63 | C | 0 | $609K |
| 23 | 3745 | Cornish | 63 | C | 0 | $277K |
| 24 | 3780 | Pike | 63 | C | 0 | — |
| 25 | 3784 | West Lebanon | 63 | C | 0 | $341K |
| 26 | 3768 | Lyme | 58 | C | 0 | $651K |
| 27 | 3580 | Franconia | 56 | C | 5 | $470K |
| 28 | 3240 | Grafton | 53 | D | 0 | $256K |
| 29 | 3285 | Thornton | 53 | D | 0 | $290K |
| 30 | 3746 | Cornish Flat | 53 | D | 0 | — |
| 31 | 3749 | Enfield Center | 53 | D | 0 | — |
| 32 | 3750 | Etna | 53 | D | 0 | $798K |
| 33 | 3779 | Piermont | 53 | D | 0 | $328K |
| 34 | 3223 | Campton | 52 | D | 3 (1 health) | $285K |
| 35 | 3574 | Bethlehem | 52 | D | 4 (4 health) | $269K |
| 36 | 3741 | Canaan | 52 | D | 14 (1 health) | $241K |
| 37 | 3238 | Glencliff | 49 | D | 12 (1 health) | $190K |
| 38 | 3266 | Rumney | 49 | D | 3 (1 health) | $264K |
| 39 | 3245 | Holderness | 47 | D | 2 (1 health) | $327K |
Recommended Buyer Guides for Grafton County
Federal and certification sources drive the ordering: EPA monitoring data, NSF certifications, FEMA flood maps, and CDC lead guidance — guides surface only when county data warrants them.
- Best Water Filters for Lead — Lead above EPA action level in 8 ZIP codes
- Best Lead Paint Test Kits — 65% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
Deep Dive Reports
Detailed analysis for Grafton County, New Hampshire
Overview
Grafton County in New Hampshire covers 39 ZIP codes with an average Home Safety Score of C (65/100).
22 of 39 ZIP codes have recorded EPA violations. 20 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.