Hillsborough County, New Hampshire
41 ZIP codes · Avg score 71/100 · Grade B · Updated 2026-06-04
Although county size varies, Hillsborough County's 41 ZIP codes share reliably safe tap water records and above-average compliance scores.
How Hillsborough County Compares
How Hillsborough County Compares
Hillsborough County scores 7 points above the New Hampshire state average (64/100) and 3 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-04
ZIP Code Risk Map
Water Quality Map: Hillsborough 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: 11.6 (asthma 10.6%, diabetes 9.2%)
Estimated additional annual cost per homeowner: $1,557, driven primarily by flood
Infrastructure: 0.387% avg pipe failure probability, 43% of ZIPs at high risk
63% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
↓ Improving trendEPA violation counts by year across Hillsborough County water systems. Health-based shown in red, total in blue.
Peak year: 2023 with 12 violations. Past 5 years: 28 total (28 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: $1,557
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
176,794 housing units in Hillsborough 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 Hillsborough County
Remediation costs are relatively manageable for most homeowners in Hillsborough 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 Hillsborough 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 Hillsborough County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Manchester Water Works | 123,500 | 87 |
| 2 | Century Village Condos | 875 | 81 |
| 3 | Samoset at Winnipesaukee | 343 | 81 |
| 4 | Villages at Chester Condos | 245 | 81 |
| 5 | Seasons at Lake Sunapee | 153 | 81 |
69 total water systems serve Hillsborough County.
All ZIP Codes in Hillsborough County
41 ZIP codes tracked in Hillsborough County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 3052 | Litchfield | 83 | B | 0 | $444K |
| 2 | 3061 | Nashua | 83 | B | 0 | — |
| 3 | 3063 | Nashua | 83 | B | 0 | $372K |
| 4 | 3064 | Nashua | 83 | B | 0 | $382K |
| 5 | 3055 | Milford | 82 | B | 2 | $364K |
| 6 | 3101 | Manchester | 80 | B | 9 (3 health) | $418K |
| 7 | 3109 | Manchester | 80 | B | 9 (3 health) | $350K |
| 8 | 3105 | Manchester | 79 | B | 9 (3 health) | — |
| 9 | 3107 | Manchester | 79 | B | 9 (3 health) | — |
| 10 | 3108 | Manchester | 79 | B | 9 (3 health) | — |
| 11 | 3111 | Manchester | 79 | B | 9 (3 health) | — |
| 12 | 3060 | Nashua | 78 | B | 0 | $339K |
| 13 | 3062 | Nashua | 78 | B | 0 | $398K |
| 14 | 3086 | Wilton | 75 | B | 0 | $370K |
| 15 | 3102 | Manchester | 75 | B | 9 (3 health) | $309K |
| 16 | 3103 | Manchester | 75 | B | 9 (3 health) | $314K |
| 17 | 3104 | Manchester | 75 | B | 9 (3 health) | $364K |
| 18 | 3440 | Antrim | 75 | B | 0 | $271K |
| 19 | 3449 | Hancock | 75 | B | 0 | $423K |
| 20 | 3071 | New Ipswich | 74 | B | 2 | $318K |
| 21 | 3049 | Hollis | 73 | B | 2 (2 health) | $623K |
| 22 | 3043 | Francestown | 72 | B | 0 | $379K |
| 23 | 3054 | Merrimack | 72 | B | 2 | $406K |
| 24 | 3051 | Hudson | 70 | B | 1 | $407K |
| 25 | 3110 | Bedford | 70 | B | 0 | $582K |
| 26 | 3442 | Bennington | 70 | B | 0 | $250K |
| 27 | 3244 | Hillsborough | 69 | C | 3 | $253K |
| 28 | 3458 | Peterborough | 67 | C | 2 | $368K |
| 29 | 3031 | Amherst | 65 | C | 1 | $491K |
| 30 | 3033 | Brookline | 63 | C | 0 | $480K |
| 31 | 3070 | New Boston | 63 | C | 0 | $436K |
| 32 | 3444 | Dublin | 63 | C | 0 | $381K |
| 33 | 3464 | Stoddard | 63 | C | 0 | $291K |
| 34 | 3045 | Goffstown | 62 | C | 6 (3 health) | $360K |
| 35 | 3076 | Pelham | 62 | C | 6 (5 health) | $485K |
| 36 | 3281 | Weare | 57 | C | 12 (6 health) | $363K |
| 37 | 3048 | Greenville | 55 | C | 7 | $275K |
| 38 | 3047 | Greenfield | 53 | D | 11 (5 health) | $315K |
| 39 | 3082 | Lyndeborough | 53 | D | 0 | $334K |
| 40 | 3468 | West Peterborough | 53 | D | 0 | — |
| 41 | 3057 | Mont Vernon | 50 | D | 0 | $479K |
Recommended Buyer Guides for Hillsborough County
Strictly editorial — no paid placements influence which guides appear; the selection draws on NSF certifications and EPA detection records for water systems serving this county.
- Best Water Filters for Lead — Lead above EPA action level in 3 ZIP codes
- Best Lead Paint Test Kits — 63% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best Sump Pumps — Flood is the top compound risk factor
- Best Mold Test Kits — Flood-driven moisture and mold risk
Deep Dive Reports
Detailed analysis for Hillsborough County, New Hampshire
Overview
Hillsborough County in New Hampshire covers 41 ZIP codes with an average Home Safety Score of B (71/100).
22 of 41 ZIP codes have recorded EPA violations. 48 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.