Hard water in Woodbury, MN
Reported by Woodbury · August 2025
- MN typical
- 160 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 24k grain
- Data
- Utility report
Woodbury water measures 160 mg/L (9.4 gpg) of hardness, hard by USGS standards. The number comes from Woodbury, dated August 2025.
Woodbury sits close to the typical Minnesota figure of 160 mg/L. Of the 10 nearest cities we track, 4 have softer water and 6 have harder. The range nearby runs from 56 mg/L in North St. Paul to 330 in Cottage Grove.
What 160 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 160 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 × 9.4 gpg = 2,106 grains a day. A 24,000-grain unit regenerates about every 11 days.
EPA record for Woodbury's water system
No health-based violations since 2016
Serves about 82,643 people from groundwater.
- Health-based
- 0
- Monitoring or reporting
- 1
- 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 Woodbury water hard?
Yes. It measures about 160 mg/L (9.4 grains per gallon), which the USGS classes as hard.
What is the water hardness in Woodbury in grains per gallon?
About 9.4 gpg. One grain per gallon equals 17.1 mg/L, so 160 mg/L divided by 17.1 gives 9.4.
What size water softener do I need in Woodbury?
For 3 people using 75 gallons each per day, 9.4 gpg works out to about 2,106 grains a day. A 24,000-grain softener covers that with a regeneration about every 11 days.
Has the Woodbury water system had EPA violations?
EPA records show no health-based violations for Woodbury since 2016. There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.
Nearby cities
- Lake Elmo249 mg/LVery hard
- Cottage Grove330 mg/LVery hard
- North St. Paul56 mg/LSoft
- Inver Grove Heights270 mg/LVery hard
- St. Paul82 mg/LModerately hard
- Maplewood56 mg/LSoft
- Mahtomedi162 mg/LHard
- Hastings270 mg/LVery hard
- Rosemount270 mg/LVery hard
- Eagan132 mg/LHard
Hardness data: TapWaterData US Water Hardness (utility report, August 15, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.