Keene, NH water hardness

Tap water hardness
15mg/L
0.9gpg
SoftCounty estimate

County estimate from 207 water samples in Cheshire County · July 2026

NH typical
20 mg/L
EPA health violations since 2016
0
Data
County estimate

Water samples from around Keene put hardness at about 15 mg/L (0.9 gpg), which would be soft on the USGS scale. Treat this as a rough guide: it is the median of 207 samples taken across Cheshire County, mostly wells and streams, not a test of Keene's treated tap water. One more reason for caution: EPA lists Keene's water system as using surface water, which is often softer than the wells behind the county figure.

Keene on the hardness scale, with nearby cities
060120180240300360+NH typical 20Concord: 13 mg/LConcord 13Manchester: 16 mg/LManchester 16Rochester: 20 mg/LRochester 20Lebanon: 22 mg/LLebanon 22Nashua: 31 mg/LNashua 31Hudson: 31 mg/LHudson 31Dover: 64 mg/LDover 64Derry: 123 mg/LDerry 123Portsmouth: 123 mg/LPortsmouth 123Keene 15mg/L as calcium carbonate060120180240300360+NH 20Concord: 13 mg/LConcord 13Manchester: 16 mg/LManchester 16Lebanon: 22 mg/LLebanon 22Nashua: 31 mg/LNashua 31Hudson: 31 mg/LHudson 31Derry: 123 mg/LDerry 12315 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Keene sits close to the typical New Hampshire figure of 20 mg/L. Of the 9 nearest cities we track, 1 has softer water and 8 have harder. The range nearby runs from 13 mg/L in Concord to 123 in Derry.

What 15 mg/L means at home

Soap and shampoo lather with very little product. Kettles and showerheads stay mostly free of white crust.

Some people notice that soap feels slow to rinse off in soft water. That slippery feel is normal and harmless.

Hardness is not a health problem, and EPA sets no limit for it. It is a matter of scale and soap.

What to do about it

Nothing, as far as hardness goes. At 15 mg/L a softener would have almost nothing to remove.

Carbon filter

If the water tastes of chlorine, a pitcher or faucet carbon filter takes care of that. It does not change hardness.

EPA record for Keene's water system

Keene Water Dept · PWSID NH1241010

No health-based violations since 2016

Serves about 30,000 people from surface water.

Health-based
0
Monitoring or reporting
0
Open now
0

EPA lists this system as serving Keene.

Health-based means a contaminant above its legal limit or a missed treatment step. Monitoring and reporting violations are late or missing tests and notices. Source: EPA ECHO, 2026Q3 export, violations with periods starting 2016 or later. Full EPA record.

Questions

Is Keene water hard?

No. It measures about 15 mg/L (0.9 grains per gallon), which the USGS classes as soft.

What is the water hardness in Keene in grains per gallon?

About 0.9 gpg. One grain per gallon equals 17.1 mg/L, so 15 mg/L divided by 17.1 gives 0.9.

Has the Keene water system had EPA violations?

EPA records show no health-based violations for Keene Water Dept since 2016.

Nearby cities

All 10 cities in New Hampshire

Hardness data: TapWaterData US Water Hardness (county estimate, July 4, 2026), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.