Hard water in Joplin, 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
The water in Joplin carries roughly 144 mg/L of dissolved calcium and magnesium, or 8.4 grains per gallon. That is hard water. TapWaterData worked it out from the calcium and magnesium levels the local utility reports (December 2020).
At 144 mg/L, Joplin is 23 mg/L above the typical Missouri figure of 121. None of the 10 nearest cities we track has softer water. The range nearby runs from 153 mg/L in Willard to 213 in Carl Junction.
What 144 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 144 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 × 8.4 gpg = 1,901 grains a day. A 24,000-grain unit regenerates about every 12 days.
EPA record for Joplin's water system
No health-based violations since 2016
Serves about 73,728 people from surface water.
- Health-based
- 0
- Monitoring or reporting
- 0
- Open now
- 0
EPA lists this system as serving Joplin.
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 Joplin water hard?
Yes. It measures about 144 mg/L (8.4 grains per gallon), which the USGS classes as hard.
What is the water hardness in Joplin in grains per gallon?
About 8.4 gpg. One grain per gallon equals 17.1 mg/L, so 144 mg/L divided by 17.1 gives 8.4.
What size water softener do I need in Joplin?
For 3 people using 75 gallons each per day, 8.4 gpg works out to about 1,901 grains a day. A 24,000-grain softener covers that with a regeneration about every 12 days.
Has the Joplin water system had EPA violations?
EPA records show no health-based violations for Mo American Joplin since 2016.
Nearby cities
- Webb City159 mg/LHard
- Carl Junction213 mg/LVery hard
- Carthage165 mg/LHard
- Neosho168 mg/LHard
- Monett180 mg/LVery hard
- Aurora208 mg/LVery hard
- Nevada157 mg/LHard
- Republic155 mg/LHard
- Willard153 mg/LHard
- Battlefield190 mg/LVery hard
Hardness data: TapWaterData US Water Hardness (calculated from utility data, December 28, 2020), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.