How hard is the water in Potomac Mills, VA?

Tap water hardness
78mg/L
4.5gpg
Moderately hard

Reported by Dale City · September 2024

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

The water in Potomac Mills carries roughly 78 mg/L of dissolved calcium and magnesium, or 4.5 grains per gallon. That is moderately hard water. The number comes from Dale City, dated September 2024.

Potomac Mills on the hardness scale, with nearby cities
060120180240300360+VA typical 65Aquia Harbour: 28 mg/LAquia Harbour 28Woodlawn: 67 mg/LWoodlawn 67Manassas: 74 mg/LManassas 74Dale City: 78 mg/LDale City 78Woodbridge: 82 mg/LWoodbridge 82Buckhall: 82 mg/LBuckhall 82Manassas Park: 82 mg/LManassas Park 82Yorkshire: 82 mg/LYorkshire 82Sudley: 82 mg/LSudley 82Long Branch: 100 mg/LLong Branch 100Potomac Mills 78mg/L as calcium carbonate060120180240300360+VA 65Woodlawn: 67 mg/LWoodlawn 67Manassas: 74 mg/LManassas 74Dale City: 78 mg/LDale City 78Woodbridge: 82 mg/LWoodbridge 82Buckhall: 82 mg/LBuckhall 82Manassas Park: 82 mg/LManassas P. 8278 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 78 mg/L, Potomac Mills is 13 mg/L above the typical Virginia figure of 65. Of the 10 nearest cities we track, 3 have softer water and 6 have harder. The range nearby runs from 28 mg/L in Aquia Harbour to 100 in Long Branch.

What 78 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 Potomac Mills

3 people × 75 gallons a day × 4.5 gpg = 1,022 grains a day. A 24,000-grain unit regenerates about every 23 days.

Size it for your household

EPA record for Potomac Mills's water system

Dale City · PWSID VA6153625

No health-based violations since 2016

Serves about 72,062 people from surface water.

Health-based
0
Monitoring or reporting
0
Open now
0

TapWaterData ties Potomac Mills to this system. EPA's service-area records do not name Potomac Mills, so check the utility printed on your water bill.

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 Potomac Mills water hard?

Somewhat. It measures about 78 mg/L (4.5 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Potomac Mills in grains per gallon?

About 4.5 gpg. One grain per gallon equals 17.1 mg/L, so 78 mg/L divided by 17.1 gives 4.5.

What size water softener do I need in Potomac Mills?

For 3 people using 75 gallons each per day, 4.5 gpg works out to about 1,022 grains a day. A 24,000-grain softener covers that with a regeneration about every 23 days.

Has the Potomac Mills water system had EPA violations?

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

Nearby cities

All 79 cities in Virginia

Hardness data: TapWaterData US Water Hardness (utility report, September 5, 2024), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.