State distribution
Hardness across indexed ZIPs
Counts describe published ZIP profiles, not a population-weighted statewide sample.
Soft · 0–60 PPM50
Moderately hard · 61–120 PPM16
Hard · 121–180 PPM9
Very hard · 181+ PPM0
State water index
New Hampshire water hardness
Search 74 indexed communities and 90 ZIP profiles, then compare the underlying utility, source, distance, and reporting context.
Median regional evidence
43PPM
Soft
Indexed range 3.2–150 PPM
- ZIP profiles
- 90
- Cities
- 74
- Matched utilities
- 243
- Counties
- 10
Understanding New Hampshire
Why local comparisons matter here
New Hampshire uses lakes, reservoirs, sand-and-gravel aquifers, and fractured bedrock wells across short but geologically varied distances.
In this index, soft is the largest category, covering 50 of 75 profiles with hardness data. The state median is 43 PPM, but the full indexed range is 3.2–150 PPM.
Evidence coverage
What the current records support
- Hardness estimate
- 83%
- Lead 90th percentile
- 86%
- Copper 90th percentile
- 46%
56
Low-confidence hardness profiles
9
Research-comparison eligible profiles
Reported source water
Utility source mix
- Groundwater
- 198
- Surface water
- 45
Highest medians
Highest eligible city medians
- 1. Nashua58 PPM
Lowest medians
Lowest eligible city medians
- 1. Nashua58 PPM
City directory
Explore New Hampshire by city
Search by city or county, then sort by name, hardness, or ZIP coverage.
74 cities · 90 ZIP profiles
74 cities found
Page 1 of 4
Alton
Belknap County · 2 ZIPs
40PPM regional
Regional range 39.2–41.6No active flag
Amherst
Hillsborough County · 1 ZIP
77PPM regional
Single regional valueNo active flag
Antrim
Hillsborough County · 1 ZIP
55PPM regional
Single regional valueNo active flag
Ashland
Grafton County · 1 ZIP
—
No regional sampleNo active flag
Bartlett
Carroll County · 1 ZIP
23PPM regional
Single regional valueNo active flag
Belmont
Belknap County · 1 ZIP
39PPM regional
Single regional valueNo active flag
Bennington
Hillsborough County · 1 ZIP
42PPM regional
Single regional valueNo active flag
Berlin
Coos County · 1 ZIP
3PPM regional
Single regional valueNo active flag
Bethlehem
Grafton County · 1 ZIP
—
No regional sampleNo active flag
Bradford
Merrimack County · 1 ZIP
15PPM regional
Single regional valueNo active flag
Bristol
Grafton County · 1 ZIP
129PPM regional
Single regional valueNo active flag
Canaan
Grafton County · 1 ZIP
—
No regional sampleNo active flag
Charlestown
Sullivan County · 1 ZIP
67PPM regional
Single regional valueNo active flag
Claremont
Sullivan County · 1 ZIP
20PPM regional
Single regional valueNo active flag
Colebrook
Coos County · 1 ZIP
46PPM regional
Single regional valueNo active flag
Concord
Merrimack County · 3 ZIPs
24PPM regional
Single regional valueNo active flag
Conway
Carroll County · 2 ZIPs
16PPM regional
Single regional valueNo active flag
Derry
Rockingham County · 2 ZIPs
74PPM regional
Single regional valueNo active flag
Dover
Strafford County · 2 ZIPs
132PPM regional
Single regional valueNo active flag
Durham
Strafford County · 1 ZIP
51PPM regional
Single regional valueNo active flag
Enfield
Grafton County · 1 ZIP
129PPM regional
Single regional valueNo active flag
Epping
Rockingham County · 1 ZIP
132PPM regional
Single regional valueNo active flag
Exeter
Rockingham County · 1 ZIP
78PPM regional
Single regional valueNo active flag
Farmington
Strafford County · 1 ZIP
42PPM regional
Single regional valueNo active flag
County comparison
Highest regional-evidence county medians
| County | Median | Range | ZIP profiles |
|---|---|---|---|
| Grafton County | 129 PPM | 82.7–135 | 12 |
| Rockingham County | 96 PPM | 51.2–150 | 10 |
| Hillsborough County | 58 PPM | 15.7–104.5 | 21 |
| Cheshire County | 55 PPM | 20–66.9 | 7 |
| Coos County | 43 PPM | 3.2–45.6 | 6 |
| Sullivan County | 43 PPM | 20–129 | 4 |
| Strafford County | 42 PPM | 24–132 | 9 |
| Belknap County | 39 PPM | 39.2–41.6 | 6 |
| Merrimack County | 32 PPM | 14.6–42 | 10 |
| Carroll County | 19 PPM | 15.5–43.3 | 5 |