Hard water in Mount Airy, MD
Reported by Town of Mount Airy · July 2024
- MD typical
- 105 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 24k grain
- Data
- Utility report
Mount Airy water measures 131 mg/L (7.7 gpg) of hardness, hard by USGS standards. The number comes from Town of Mount Airy, dated July 2024.
At 131 mg/L, Mount Airy is 26 mg/L above the typical Maryland figure of 105. Of the 10 nearest cities we track, 8 have softer water and 2 have harder. The range nearby runs from 4 mg/L in Fort Meade to 216 in Towson.
What 131 mg/L means at home
Expect white crust on faucets and showerheads, plus spots on dishes that come out of the dishwasher.
Kettles collect scale quickly. Water heaters build up sediment at the bottom of the tank, which makes them work harder over time.
Soap and detergent need a little more to lather, and soap scum shows up in the tub.
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
At 131 mg/L most of the trouble is scale, and only a few things deal with it.
Ion-exchange water softener
The standard whole-house fix. It swaps calcium and magnesium for sodium or potassium and needs salt plus a drain. Size it with the calculator below.
Salt-free conditioner
No salt and no drain line. It changes how minerals form scale instead of removing them, so water still tests hard.
Reverse osmosis or carbon filter
Under-sink reverse osmosis removes minerals from drinking water only. Plain carbon filters improve taste but do not soften.
3 people × 75 gallons a day × 7.7 gpg = 1,724 grains a day. A 24,000-grain unit regenerates about every 13 days.
EPA record for Mount Airy's water system
No health-based violations since 2016
Serves about 9,890 people from groundwater.
- 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 Mount Airy water hard?
Yes. It measures about 131 mg/L (7.7 grains per gallon), which the USGS classes as hard.
What is the water hardness in Mount Airy in grains per gallon?
About 7.7 gpg. One grain per gallon equals 17.1 mg/L, so 131 mg/L divided by 17.1 gives 7.7.
What size water softener do I need in Mount Airy?
For 3 people using 75 gallons each per day, 7.7 gpg works out to about 1,724 grains a day. A 24,000-grain softener covers that with a regeneration about every 13 days.
Has the Mount Airy water system had EPA violations?
EPA records show no health-based violations for Town of Mount Airy since 2016. There were also 4 monitoring or reporting violations, which are about late or missing tests and notices.
Nearby cities
- Urbana132 mg/LHard
- Frederick105 mg/LModerately hard
- Westminster62 mg/LModerately hard
- Ellicott City82 mg/LModerately hard
- Columbia74 mg/LModerately hard
- Poolesville84 mg/LModerately hard
- Brunswick84 mg/LModerately hard
- Takoma Park110 mg/LModerately hard
- Towson216 mg/LVery hard
- Fort Meade4 mg/LSoft
Hardness data: TapWaterData US Water Hardness (utility report, July 31, 2024), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.