Hard water in Elk River, MN
County estimate from 260 water samples in Sherburne County · July 2026
- MN typical
- 160 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 24k grain
- Data
- County estimate
Water samples from around Elk River put hardness at about 170 mg/L (9.9 gpg), which would be hard on the USGS scale. Treat this as a rough guide: it is the median of 260 samples taken across Sherburne County, mostly wells and streams, not a test of Elk River's treated tap water.
At 170 mg/L, Elk River is close to the typical Minnesota figure of 160 mg/L. Of the 10 nearest cities we track, 3 have softer water and 7 have harder. The range nearby runs from 39 mg/L in Lino Lakes to 260 in St. Michael.
What 170 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 170 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 × 9.9 gpg = 2,236 grains a day. A 24,000-grain unit regenerates about every 10 days.
EPA record for Elk River's water system
No health-based violations since 2016
Serves about 19,532 people from groundwater.
- Health-based
- 0
- Monitoring or reporting
- 0
- Open now
- 0
EPA lists this system as serving Elk River.
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 Elk River water hard?
Yes. It measures about 170 mg/L (9.9 grains per gallon), which the USGS classes as hard.
What is the water hardness in Elk River in grains per gallon?
About 9.9 gpg. One grain per gallon equals 17.1 mg/L, so 170 mg/L divided by 17.1 gives 9.9.
What size water softener do I need in Elk River?
For 3 people using 75 gallons each per day, 9.9 gpg works out to about 2,236 grains a day. A 24,000-grain softener covers that with a regeneration about every 10 days.
Has the Elk River water system had EPA violations?
EPA records show no health-based violations for Elk River since 2016.
Nearby cities
- St. Michael260 mg/LVery hard
- Andover200 mg/LVery hard
- Champlin234 mg/LVery hard
- Coon Rapids201 mg/LVery hard
- Brooklyn Park120 mg/LModerately hard
- Blaine191 mg/LVery hard
- Brooklyn Center79 mg/LModerately hard
- Robbinsdale201 mg/LVery hard
- New Brighton230 mg/LVery hard
- Lino Lakes39 mg/LSoft
Hardness data: TapWaterData US Water Hardness (county estimate, July 4, 2026), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.