How hard is the water in Frederick, MD?

Tap water hardness
105mg/L
6.1gpg
Moderately hard

Reported by City of Frederick · June 2025

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

Tap water in Frederick has about 105 mg/L of hardness, which is 6.1 grains per gallon. On the USGS scale that counts as moderately hard. The number comes from City of Frederick, dated June 2025.

Frederick on the hardness scale, with nearby cities
060120180240300360+MD typical 105Fort Meade: 4 mg/LFort Meade 4Westminster: 62 mg/LWestminster 62Columbia: 74 mg/LColumbia 74Ellicott City: 82 mg/LEllicott City 82Brunswick: 84 mg/LBrunswick 84Poolesville: 84 mg/LPoolesville 84Takoma Park: 110 mg/LTakoma Park 110Hagerstown: 126 mg/LHagerstown 126Mount Airy: 131 mg/LMount Airy 131Urbana: 132 mg/LUrbana 132Frederick 105mg/L as calcium carbonate060120180240300360+MD 105Westminster: 62 mg/LWestminster 62Brunswick: 84 mg/LBrunswick 84Poolesville: 84 mg/LPoolesville 84Hagerstown: 126 mg/LHagerstown 126Mount Airy: 131 mg/LMount Airy 131Urbana: 132 mg/LUrbana 132105 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 105 mg/L, Frederick is close to the typical Maryland figure of 105 mg/L. Of the 10 nearest cities we track, 6 have softer water and 4 have harder. The range nearby runs from 4 mg/L in Fort Meade to 132 in Urbana.

What 105 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 Frederick

3 people × 75 gallons a day × 6.1 gpg = 1,381 grains a day. A 24,000-grain unit regenerates about every 17 days.

Size it for your household

EPA record for Frederick's water system

City of Frederick · PWSID MD0100015

No health-based violations since 2016

Serves about 54,000 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 Frederick water hard?

Somewhat. It measures about 105 mg/L (6.1 grains per gallon), which the USGS classes as moderately hard.

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

About 6.1 gpg. One grain per gallon equals 17.1 mg/L, so 105 mg/L divided by 17.1 gives 6.1.

What size water softener do I need in Frederick?

For 3 people using 75 gallons each per day, 6.1 gpg works out to about 1,381 grains a day. A 24,000-grain softener covers that with a regeneration about every 17 days.

Has the Frederick water system had EPA violations?

EPA records show no health-based violations for City of Frederick since 2016.

Nearby cities

All 24 cities in Maryland

Hardness data: TapWaterData US Water Hardness (utility report, June 16, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.