Hard water in Houma, LA
County estimate from 2,292 water samples in Terrebonne Parish · July 2026
- LA typical
- 102 mg/L
- Softener for 3 people
- 48k grain
- Data
- County estimate
Water samples from around Houma put hardness at about 360 mg/L (21.1 gpg), which would be very hard on the USGS scale. Treat this as a rough guide: it is the median of 2,292 samples taken across Terrebonne Parish, mostly wells and streams, not a test of Houma's treated tap water.
At 360 mg/L, Houma is 258 mg/L above the typical Louisiana figure of 102. None of the 10 nearest cities we track has harder water. The range nearby runs from 66 mg/L in Prairieville to 154 in Elmwood.
What 360 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 360 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 × 21.1 gpg = 4,736 grains a day. A 48,000-grain unit regenerates about every 10 days.
EPA record for Houma's water system
We could not match Houma to a community water system in EPA's records. Your water bill or the yearly Consumer Confidence Report names the system and its ID.
Questions
Is Houma water hard?
Yes. It measures about 360 mg/L (21.1 grains per gallon), which the USGS classes as very hard.
What is the water hardness in Houma in grains per gallon?
About 21.1 gpg. One grain per gallon equals 17.1 mg/L, so 360 mg/L divided by 17.1 gives 21.1.
What size water softener do I need in Houma?
For 3 people using 75 gallons each per day, 21.1 gpg works out to about 4,736 grains a day. A 48,000-grain softener covers that with a regeneration about every 10 days.
Nearby cities
- Elmwood154 mg/LHard
- Westwego154 mg/LHard
- Bridge City154 mg/LHard
- Marrero154 mg/LHard
- Jefferson154 mg/LHard
- Metairie135 mg/LHard
- Gretna153 mg/LHard
- Belle Chasse153 mg/LHard
- Prairieville66 mg/LModerately hard
- New Orleans153 mg/LHard
Hardness data: TapWaterData US Water Hardness (county estimate, July 4, 2026), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.