Hard water in Hopkins, MN
Reported by Minnetonka · July 2025
- MN typical
- 160 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 24k grain
- Data
- Utility report
Hopkins water measures 163 mg/L (9.5 gpg) of hardness, hard by USGS standards. The number comes from Minnetonka, dated July 2025.
Hopkins sits close to the typical Minnesota figure of 160 mg/L. Of the 10 nearest cities we track, 8 have softer water and 2 have harder. The range nearby runs from 79 mg/L in Brooklyn Center to 201 in Robbinsdale.
What 163 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 163 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 × 9.5 gpg = 2,142 grains a day. A 24,000-grain unit regenerates about every 11 days.
EPA record for Hopkins's water system
No health-based violations since 2016
Serves about 19,462 people from groundwater.
- Health-based
- 0
- Monitoring or reporting
- 0
- Open now
- 0
EPA lists Hopkins as the system serving Hopkins. The hardness figure above comes from a different system's report, which TapWaterData uses for Hopkins.
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 Hopkins water hard?
Yes. It measures about 163 mg/L (9.5 grains per gallon), which the USGS classes as hard.
What is the water hardness in Hopkins in grains per gallon?
About 9.5 gpg. One grain per gallon equals 17.1 mg/L, so 163 mg/L divided by 17.1 gives 9.5.
What size water softener do I need in Hopkins?
For 3 people using 75 gallons each per day, 9.5 gpg works out to about 2,142 grains a day. A 24,000-grain softener covers that with a regeneration about every 11 days.
Has the Hopkins water system had EPA violations?
EPA records show no health-based violations for Hopkins since 2016.
Nearby cities
- St. Louis Park112 mg/LModerately hard
- Minnetonka186 mg/LVery hard
- Edina146 mg/LHard
- Golden Valley90 mg/LModerately hard
- Eden Prairie99 mg/LModerately hard
- Minneapolis89 mg/LModerately hard
- Robbinsdale201 mg/LVery hard
- Bloomington100 mg/LModerately hard
- Chanhassen121 mg/LHard
- Brooklyn Center79 mg/LModerately hard
Hardness data: TapWaterData US Water Hardness (utility report, July 18, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.