Hard water in St. Joseph, MO
Calculated from the utility's calcium and magnesium results · December 2020
- MO typical
- 121 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 24k grain
- Data
- Calculated from utility data
St. Joseph water measures 206 mg/L (12.1 gpg) of hardness, very hard by USGS standards. TapWaterData worked it out from the calcium and magnesium levels the local utility reports (December 2020).
St. Joseph sits 85 mg/L above the typical Missouri figure of 121. None of the 10 nearest cities we track has harder water. The range nearby runs from 106 mg/L in Smithville to 172 in Parkville.
What 206 mg/L means at home
Scale forms fast here. Kettles and coffee makers need regular descaling, and showerheads clog unless you clean them.
Tank water heaters collect mineral sediment that insulates the water from the burner, so flushing the tank matters more than usual.
Dishes and glass shower doors spot easily. Soap scum and a dull film on hair or laundry are common complaints.
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 206 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 × 12.1 gpg = 2,718 grains a day. A 24,000-grain unit regenerates about every 8 days.
EPA record for St. Joseph's water system
No health-based violations since 2016
Serves about 89,171 people from groundwater.
- Health-based
- 0
- Monitoring or reporting
- 0
- Open now
- 0
EPA lists this system as serving St. Joseph.
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 St. Joseph water hard?
Yes. It measures about 206 mg/L (12.1 grains per gallon), which the USGS classes as very hard.
What is the water hardness in St. Joseph in grains per gallon?
About 12.1 gpg. One grain per gallon equals 17.1 mg/L, so 206 mg/L divided by 17.1 gives 12.1.
What size water softener do I need in St. Joseph?
For 3 people using 75 gallons each per day, 12.1 gpg works out to about 2,718 grains a day. A 24,000-grain softener covers that with a regeneration about every 8 days.
Has the St. Joseph water system had EPA violations?
EPA records show no health-based violations for Mo American ST Joseph since 2016.
Nearby cities
- Savannah118 mg/LModerately hard
- Smithville106 mg/LModerately hard
- Cameron143 mg/LHard
- Kearney135 mg/LHard
- Parkville172 mg/LHard
- Gladstone117 mg/LModerately hard
- Maryville112 mg/LModerately hard
- Liberty162 mg/LHard
- Excelsior Springs154 mg/LHard
- North Kansas City116 mg/LModerately hard
Hardness data: TapWaterData US Water Hardness (calculated from utility data, December 14, 2020), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.