Hard water in Marshall, MO
Calculated from the utility's calcium and magnesium results · December 2020
- MO typical
- 121 mg/L
- EPA health violations since 2016
- 7
- Softener for 3 people
- 24k grain
- Data
- Calculated from utility data
The water in Marshall carries roughly 143 mg/L of dissolved calcium and magnesium, or 8.3 grains per gallon. That is hard water. TapWaterData worked it out from the calcium and magnesium levels the local utility reports (December 2020).
At 143 mg/L, Marshall is 22 mg/L above the typical Missouri figure of 121. Of the 10 nearest cities we track, 3 have softer water and 7 have harder. The range nearby runs from 73 mg/L in Macon to 310 in Blue Springs.
What 143 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 143 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 × 8.3 gpg = 1,879 grains a day. A 24,000-grain unit regenerates about every 12 days.
EPA record for Marshall's water system
7 health-based violations since 2016
Serves about 12,934 people from groundwater.
- Health-based
- 7
- Monitoring or reporting
- 0
- Open now
- 0
EPA lists this system as serving Marshall.
| Contaminant or rule | Violations | Period | Status |
|---|---|---|---|
| Total trihalomethanes (TTHM)a disinfection byproduct | 6 | 2016–2018 | Resolved |
| Groundwater Ruletreatment of well water | 1 | 2018 | Resolved |
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 Marshall water hard?
Yes. It measures about 143 mg/L (8.3 grains per gallon), which the USGS classes as hard.
What is the water hardness in Marshall in grains per gallon?
About 8.3 gpg. One grain per gallon equals 17.1 mg/L, so 143 mg/L divided by 17.1 gives 8.3.
What size water softener do I need in Marshall?
For 3 people using 75 gallons each per day, 8.3 gpg works out to about 1,879 grains a day. A 24,000-grain softener covers that with a regeneration about every 12 days.
Has the Marshall water system had EPA violations?
EPA records show 7 health-based violations for Marshall PWS since 2016, involving Total trihalomethanes (TTHM), Groundwater Rule.
Nearby cities
- Sedalia241 mg/LVery hard
- Warrensburg233 mg/LVery hard
- Richmond190 mg/LVery hard
- Moberly135 mg/LHard
- Columbia190 mg/LVery hard
- Oak Grove176 mg/LHard
- Chillicothe108 mg/LModerately hard
- Blue Springs310 mg/LVery hard
- Excelsior Springs154 mg/LHard
- Macon73 mg/LModerately 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.