How hard is the water in Meridian, ID?

Tap water hardness
86mg/L
5.0gpg
Moderately hardReports range 86–108

Reported by Veolia Water Idaho · October 2025

ID typical
118 mg/L
EPA health violations since 2016
0
Softener for 3 people
24k grain
Data
Utility report

Meridian water measures 86 mg/L (5.0 gpg) of hardness, moderately hard by USGS standards. The number comes from Veolia Water Idaho, dated October 2025. Reports for this system disagree, with values from 86 to 108 mg/L.

Meridian on the hardness scale, with nearby cities
060120180240300360+ID typical 118Kuna: 90 mg/LKuna 90Eagle: 90 mg/LEagle 90Garden City: 90 mg/LGarden City 90Boise City: 90 mg/LBoise City 90Lewiston: 122 mg/LLewiston 122Star: 124 mg/LStar 124Nampa: 170 mg/LNampa 170Caldwell: 170 mg/LCaldwell 170Chubbuck: 340 mg/LChubbuck 340Twin Falls: 400 mg/LTwin Falls 400Meridian 86mg/L as calcium carbonate060120180240300360+ID 118Kuna: 90 mg/LKuna 90Eagle: 90 mg/LEagle 90Garden City: 90 mg/LGarden City 90Boise City: 90 mg/LBoise City 90Star: 124 mg/LStar 124Nampa: 170 mg/LNampa 17086 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Meridian sits 32 mg/L below the typical Idaho figure of 118. None of the 10 nearest cities we track has softer water. The range nearby runs from 90 mg/L in Kuna to 400 in Twin Falls.

What 86 mg/L means at home

You may see faint white spots on glasses and shower doors after the water dries.

Scale builds up slowly. A kettle or coffee maker needs descaling now and then, maybe every few months.

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

Optional. Plenty of households at this level live with it and descale the kettle now and then.

Water softener

Worth a look if spots on glass bother you, or if your tankless water heater manual asks for softer water.

Carbon filter

Improves taste and removes chlorine. It leaves calcium and magnesium in place.

Softener size for Meridian

3 people × 75 gallons a day × 5.0 gpg = 1,130 grains a day. A 24,000-grain unit regenerates about every 21 days.

Size it for your household

EPA record for Meridian's water system

Meridian Water Dept · PWSID ID4010097

No health-based violations since 2016

Serves about 152,070 people from groundwater.

Health-based
0
Monitoring or reporting
3
Open now
0

EPA lists Meridian Water Dept as the system serving Meridian. The hardness figure above comes from a different system's report, which TapWaterData uses for Meridian.

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 Meridian water hard?

Somewhat. It measures about 86 mg/L (5.0 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Meridian in grains per gallon?

About 5.0 gpg. One grain per gallon equals 17.1 mg/L, so 86 mg/L divided by 17.1 gives 5.0.

What size water softener do I need in Meridian?

For 3 people using 75 gallons each per day, 5.0 gpg works out to about 1,130 grains a day. A 24,000-grain softener covers that with a regeneration about every 21 days.

Has the Meridian water system had EPA violations?

EPA records show no health-based violations for Meridian Water Dept since 2016. There were also 3 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 21 cities in Idaho

Hardness data: TapWaterData US Water Hardness (utility report, October 10, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.