How hard is the water in Mount Vista, WA?

Tap water hardness
86mg/L
5.0gpg
Moderately hard

Reported by Clark Public Utilities · September 2025

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

Mount Vista water measures 86 mg/L (5.0 gpg) of hardness, moderately hard by USGS standards. The number comes from Clark Public Utilities, dated September 2025.

Mount Vista on the hardness scale, with nearby cities
060120180240300360+WA typical 36Battle Ground: 85 mg/LBattle Ground 85Barberton: 86 mg/LBarberton 86Salmon Creek: 86 mg/LSalmon Creek 86Felida: 86 mg/LFelida 86Lake Shore: 86 mg/LLake Shore 86Ridgefield: 86 mg/LRidgefield 86Hazel Dell: 101 mg/LHazel Dell 101Five Corners: 101 mg/LFive Corners 101Orchards: 101 mg/LOrchards 101Minnehaha: 105 mg/LMinnehaha 105Mount Vista 86mg/L as calcium carbonate060120180240300360+WA 36Barberton: 86 mg/LBarberton 86Salmon Creek: 86 mg/LSalmon Cre. 86Felida: 86 mg/LFelida 86Lake Shore: 86 mg/LLake Shore 86Hazel Dell: 101 mg/LHazel Dell 101Five Corners: 101 mg/LFive Corne. 10186 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

At 86 mg/L, Mount Vista is 50 mg/L above the typical Washington figure of 36. Of the 10 nearest cities we track, 1 has softer water and 4 have harder. The range nearby runs from 85 mg/L in Battle Ground to 105 in Minnehaha.

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 Mount Vista

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 Mount Vista's water system

Clark Public Utilities · PWSID WA5313333

No health-based violations since 2016

Serves about 153,526 people from groundwater.

Health-based
0
Monitoring or reporting
1
Open now
0

TapWaterData ties Mount Vista to this system. EPA's service-area records do not name Mount Vista, so check the utility printed on your water bill.

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 Mount Vista 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 Mount Vista 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 Mount Vista?

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 Mount Vista water system had EPA violations?

EPA records show no health-based violations for Clark Public Utilities since 2016. There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.

Nearby cities

All 145 cities in Washington

Hardness data: TapWaterData US Water Hardness (utility report, September 8, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.