Somerville, MA water hardness

Tap water hardness
20mg/L
1.1gpg
Soft

Reported by Somerville Water Dept. (MWRA) · September 2025

MA typical
38 mg/L
EPA health violations since 2016
1
Data
Utility report

The water in Somerville carries roughly 20 mg/L of dissolved calcium and magnesium, or 1.1 grains per gallon. That is soft water. The number comes from Somerville Water Dept. (MWRA), dated September 2025.

Somerville on the hardness scale, with nearby cities
060120180240300360+MA typical 38Everett: 16 mg/LEverett 16Chelsea: 16 mg/LChelsea 16Belmont: 16 mg/LBelmont 16Watertown: 16 mg/LWatertown 16Arlington: 17 mg/LArlington 17Melrose: 18 mg/LMelrose 18Winchester: 20 mg/LWinchester 20Medford: 21 mg/LMedford 21Malden: 25 mg/LMalden 25Cambridge: 60 mg/LCambridge 60Somerville 20mg/L as calcium carbonate060120180240300360+MA 38Everett: 16 mg/LEverett 16Chelsea: 16 mg/LChelsea 16Arlington: 17 mg/LArlington 17Medford: 21 mg/LMedford 21Malden: 25 mg/LMalden 25Cambridge: 60 mg/LCambridge 6020 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Somerville sits 18 mg/L below the typical Massachusetts figure of 38. Of the 10 nearest cities we track, 6 have softer water and 3 have harder. The range nearby runs from 16 mg/L in Everett to 60 in Cambridge.

What 20 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 20 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 Somerville's water system

Somerville Water Dept. (MWRA) · PWSID MA3274000

1 health-based violation since 2016

Serves about 81,045 people from surface water.

Health-based
1
Monitoring or reporting
1
Open now
0
20162017201820192020202120222023202420252026Lead and Copper Rule'16'18'20'22'24'26Lead and Copper Rule
Each dot is one health-based violation, placed at the start of its compliance period.
Contaminant or ruleViolationsPeriodStatus
Lead and Copper Rulecorrosion control and lead sampling12019Resolved

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 Somerville water hard?

No. It measures about 20 mg/L (1.1 grains per gallon), which the USGS classes as soft.

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

About 1.1 gpg. One grain per gallon equals 17.1 mg/L, so 20 mg/L divided by 17.1 gives 1.1.

Has the Somerville water system had EPA violations?

EPA records show 1 health-based violation for Somerville Water Dept. (MWRA) since 2016, involving Lead and Copper Rule. There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.

Nearby cities

All 104 cities in Massachusetts

Hardness data: TapWaterData US Water Hardness (utility report, September 30, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.