Belknap County, New Hampshire
20 ZIP codes · Avg score 67/100 · Grade C · Updated 2026-07-19
ZipCheckup grade for Belknap: C.
A mixed picture - some signals here are worth your attention.
Belknap County's water quality grade reflects a middle-ground assessment - its 20 ZIP codes range from fully compliant to violation-flagged.
How Belknap County Compares
How Belknap County Compares
Belknap County scores 3 points above the New Hampshire state average (64/100) and 1 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-07-19
ZIP Code Risk Map
Water Quality Map: Belknap 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: 12.7 (asthma 10.3%, diabetes 10.4%)
Estimated additional annual cost per homeowner: $1,240, driven primarily by sea_level
Infrastructure: 0.386% avg pipe failure probability, 50% of ZIPs at high risk
60.3% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
↑ Worsening trendEPA violation counts by year across Belknap County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 8 violations. Past 5 years: 24 total (24 health-based). Health-based violations are rising versus the prior 2-year window - worth closer monitoring.
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: $1,240
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
41,001 housing units in Belknap 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 Belknap County
Remediation costs are relatively manageable for most homeowners in Belknap 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 Belknap County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water systems serving Belknap County
8 community water systems serving Belknap County.
- B
- B
- B
- C
- D
- C
Show all 8 water systems
- B
- F
35 total water systems serve Belknap County.
Systems with the most violations in Belknap County
5 water systems with recorded EPA violations.
- F
- B
- D
- B
- B
All ZIP Codes in Belknap County
20 ZIP codes tracked in Belknap County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 03247 | Laconia | 83 | B | 1 | — |
| 2 | 03246 | Laconia | 78 | B | 1 | $308K |
| 3 | 03253 | Meredith | 78 | B | 6 (3 health) | $445K |
| 4 | 03218 | Barnstead | 75 | B | 0 | $305K |
| 5 | 03226 | Center Harbor | 75 | B | 0 | $388K |
| 6 | 03252 | Lochmere | 75 | B | 1 | — |
| 7 | 03269 | Sanbornton | 75 | B | 1 | $393K |
| 8 | 03249 | Gilford | 73 | B | 14 (2 health) | $389K |
| 9 | 03298 | Tilton | 71 | B | 2 | — |
| 10 | 03299 | Tilton | 71 | B | 2 | — |
| 11 | 03289 | Winnisquam | 70 | B | 5 | — |
| 12 | 03276 | Tilton | 69 | C | 2 | $246K |
| 13 | 03225 | Center Barnstead | 63 | C | 0 | $309K |
| 14 | 03237 | Gilmanton | 63 | C | 0 | $318K |
| 15 | 03282 | Wentworth | 63 | C | 0 | $274K |
| 16 | 03810 | Alton Bay | 63 | C | 0 | $573K |
| 17 | 03809 | Alton | 55 | C | 11 (3 health) | $332K |
| 18 | 03220 | Belmont | 53 | D | 1 | $265K |
| 19 | 03837 | Gilmanton Iron Works | 53 | D | 0 | $366K |
| 20 | 03256 | New Hampton | 33 | F | 33 (23 health) | $363K |
Recommended Buyer Guides for Belknap County
Editorial-only picks, screened against the EPA detections on file.
- Best Water Filters for Lead — Lead above EPA action level in 3 ZIP codes
- Best Lead Paint Test Kits — 60.3% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
Deep Dive Reports
Detailed analysis for Belknap County, New Hampshire
Overview
Belknap County in New Hampshire covers 20 ZIP codes with an average Home Safety Score of C (67/100).
13 of 20 ZIP codes have recorded EPA violations. 31 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.