Nashua, NH water hardness

Tap water hardness
31mg/L
1.8gpg
Soft

Reported by Pennichuck Water Works · October 2025

NH typical
20 mg/L
EPA health violations since 2016
0
Data
Utility report

The water in Nashua carries roughly 31 mg/L of dissolved calcium and magnesium, or 1.8 grains per gallon. That is soft water. The number comes from Pennichuck Water Works, dated October 2025.

Nashua on the hardness scale, with nearby cities
060120180240300360+NH typical 20Concord: 13 mg/LConcord 13Keene: 15 mg/LKeene 15Manchester: 16 mg/LManchester 16Rochester: 20 mg/LRochester 20Lebanon: 22 mg/LLebanon 22Hudson: 31 mg/LHudson 31Dover: 64 mg/LDover 64Derry: 123 mg/LDerry 123Portsmouth: 123 mg/LPortsmouth 123Nashua 31mg/L as calcium carbonate060120180240300360+NH 20Concord: 13 mg/LConcord 13Manchester: 16 mg/LManchester 16Hudson: 31 mg/LHudson 31Dover: 64 mg/LDover 64Derry: 123 mg/LDerry 123Portsmouth: 123 mg/LPortsmouth 12331 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

At 31 mg/L, Nashua is 11 mg/L above the typical New Hampshire figure of 20. Of the 9 nearest cities we track, 5 have softer water and 3 have harder. The range nearby runs from 13 mg/L in Concord to 123 in Derry.

What 31 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 31 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 Nashua's water system

Pennichuck Water Works · PWSID NH1621010

No health-based violations since 2016

Serves about 88,853 people from surface water.

Health-based
0
Monitoring or reporting
0
Open now
0

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 Nashua water hard?

No. It measures about 31 mg/L (1.8 grains per gallon), which the USGS classes as soft.

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

About 1.8 gpg. One grain per gallon equals 17.1 mg/L, so 31 mg/L divided by 17.1 gives 1.8.

Has the Nashua water system had EPA violations?

EPA records show no health-based violations for Pennichuck Water Works since 2016.

Nearby cities

All 10 cities in New Hampshire

Hardness data: TapWaterData US Water Hardness (utility report, October 22, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.