How hard is the water in Dover, NH?

Tap water hardness
64mg/L
3.8gpg
Moderately hard

Reported by Dover Water Dept · October 2025

NH typical
20 mg/L
EPA health violations since 2016
0
Softener for 3 people
24k grain
Data
Utility report

Dover water measures 64 mg/L (3.8 gpg) of hardness, moderately hard by USGS standards. The number comes from Dover Water Dept, dated October 2025.

Dover 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 31Nashua: 31 mg/LNashua 31Portsmouth: 123 mg/LPortsmouth 123Derry: 123 mg/LDerry 123Dover 64mg/L as calcium carbonate060120180240300360+NH 20Concord: 13 mg/LConcord 13Manchester: 16 mg/LManchester 16Rochester: 20 mg/LRochester 20Hudson: 31 mg/LHudson 31Portsmouth: 123 mg/LPortsmouth 123Derry: 123 mg/LDerry 12364 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 64 mg/L, Dover is 44 mg/L above the typical New Hampshire figure of 20. Of the 9 nearest cities we track, 7 have softer water and 2 have harder. The range nearby runs from 13 mg/L in Concord to 123 in Portsmouth.

What 64 mg/L means at home

You may see faint white spots on glasses and shower doors after the water dries.

Scale builds up slowly. A kettle or coffee maker needs descaling now and then, maybe every few months.

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

Optional. Plenty of households at this level live with it and descale the kettle now and then.

Water softener

Worth a look if spots on glass bother you, or if your tankless water heater manual asks for softer water.

Carbon filter

Improves taste and removes chlorine. It leaves calcium and magnesium in place.

Softener size for Dover

3 people × 75 gallons a day × 3.8 gpg = 844 grains a day. A 24,000-grain unit regenerates about every 28 days.

Size it for your household

EPA record for Dover's water system

Dover Water Dept · PWSID NH0651010

No health-based violations since 2016

Serves about 29,000 people from groundwater.

Health-based
0
Monitoring or reporting
1
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 Dover water hard?

Somewhat. It measures about 64 mg/L (3.8 grains per gallon), which the USGS classes as moderately hard.

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

About 3.8 gpg. One grain per gallon equals 17.1 mg/L, so 64 mg/L divided by 17.1 gives 3.8.

What size water softener do I need in Dover?

For 3 people using 75 gallons each per day, 3.8 gpg works out to about 844 grains a day. A 24,000-grain softener covers that with a regeneration about every 28 days.

Has the Dover water system had EPA violations?

EPA records show no health-based violations for Dover Water Dept since 2016. There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.

Nearby cities

All 10 cities in New Hampshire

Hardness data: TapWaterData US Water Hardness (utility report, October 29, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.