How hard is the water in Randolph, MA?

Tap water hardness
68mg/L
4.0gpg
Moderately hardReports range 68–82

Reported by Randolph Water Department · September 2025

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

Tap water in Randolph has about 68 mg/L of hardness, which is 4.0 grains per gallon. On the USGS scale that counts as moderately hard. The number comes from Randolph Water Department, dated September 2025. Reports for this system disagree, with values from 68 to 82 mg/L.

Randolph on the hardness scale, with nearby cities
060120180240300360+MA typical 38Weymouth: 28 mg/LWeymouth 28Quincy: 38 mg/LQuincy 38Milton: 44 mg/LMilton 44Norwood: 46 mg/LNorwood 46Sharon: 47 mg/LSharon 47Brockton: 49 mg/LBrockton 49Braintree: 55 mg/LBraintree 55Abington: 67 mg/LAbington 67Holbrook: 74 mg/LHolbrook 74Dedham: 110 mg/LDedham 110Randolph 68mg/L as calcium carbonate060120180240300360+MA 38Weymouth: 28 mg/LWeymouth 28Quincy: 38 mg/LQuincy 38Milton: 44 mg/LMilton 44Braintree: 55 mg/LBraintree 55Abington: 67 mg/LAbington 67Holbrook: 74 mg/LHolbrook 7468 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 68 mg/L, Randolph is 30 mg/L above the typical Massachusetts figure of 38. Of the 10 nearest cities we track, 8 have softer water and 2 have harder. The range nearby runs from 28 mg/L in Weymouth to 110 in Dedham.

What 68 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 Randolph

3 people × 75 gallons a day × 4.0 gpg = 889 grains a day. A 24,000-grain unit regenerates about every 27 days.

Size it for your household

EPA record for Randolph's water system

Randolph Water Department · PWSID MA4244000

No health-based violations since 2016

Serves about 35,114 people from surface water.

Health-based
0
Monitoring or reporting
4
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 Randolph water hard?

Somewhat. It measures about 68 mg/L (4.0 grains per gallon), which the USGS classes as moderately hard.

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

About 4.0 gpg. One grain per gallon equals 17.1 mg/L, so 68 mg/L divided by 17.1 gives 4.0.

What size water softener do I need in Randolph?

For 3 people using 75 gallons each per day, 4.0 gpg works out to about 889 grains a day. A 24,000-grain softener covers that with a regeneration about every 27 days.

Has the Randolph water system had EPA violations?

EPA records show no health-based violations for Randolph Water Department since 2016. There were also 4 monitoring or reporting violations, 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 22, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.