Hard water in Poplar Bluff, MO
Calculated from the utility's calcium and magnesium results · December 2020
- MO typical
- 121 mg/L
- EPA health violations since 2016
- 23
- Softener for 3 people
- 24k grain
- Data
- Calculated from utility data
Poplar Bluff water measures 165 mg/L (9.7 gpg) of hardness, hard by USGS standards. TapWaterData worked it out from the calcium and magnesium levels the local utility reports (December 2020).
At 165 mg/L, Poplar Bluff is 44 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 21 mg/L in Caruthersville to 565 in Park Hills.
What 165 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 165 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 × 9.7 gpg = 2,176 grains a day. A 24,000-grain unit regenerates about every 11 days.
EPA record for Poplar Bluff's water system
23 health-based violations since 2016
Serves about 17,043 people from surface water.
- Health-based
- 23
- Monitoring or reporting
- 0
- Open now
- 0
EPA lists this system as serving Poplar Bluff.
| Contaminant or rule | Violations | Period | Status |
|---|---|---|---|
| Haloacetic acids (HAA5)a disinfection byproduct | 2 | 2016–2025 | Resolved |
| Total trihalomethanes (TTHM)a disinfection byproduct | 6 | 2016–2017 | Resolved |
| Surface Water Treatment Rule (LT2)filtration and disinfection | 15 | 2016–2017 | 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 Poplar Bluff water hard?
Yes. It measures about 165 mg/L (9.7 grains per gallon), which the USGS classes as hard.
What is the water hardness in Poplar Bluff in grains per gallon?
About 9.7 gpg. One grain per gallon equals 17.1 mg/L, so 165 mg/L divided by 17.1 gives 9.7.
What size water softener do I need in Poplar Bluff?
For 3 people using 75 gallons each per day, 9.7 gpg works out to about 2,176 grains a day. A 24,000-grain softener covers that with a regeneration about every 11 days.
Has the Poplar Bluff water system had EPA violations?
EPA records show 23 health-based violations for Poplar Bluff PWS since 2016, involving Haloacetic acids (HAA5), Total trihalomethanes (TTHM), Surface Water Treatment Rule (LT2).
Nearby cities
- Kennett57 mg/LSoft
- Sikeston163 mg/LHard
- Caruthersville21 mg/LSoft
- Jackson268 mg/LVery hard
- Cape Girardeau237 mg/LVery hard
- Farmington276 mg/LVery hard
- Park Hills565 mg/LVery hard
- Bonne Terre339 mg/LVery hard
- West Plains248 mg/LVery hard
- De Soto312 mg/LVery hard
Hardness data: TapWaterData US Water Hardness (calculated from utility data, December 30, 2020), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.