How hard is the water in Poulsbo, WA?

Tap water hardness
67mg/L
3.9gpg
Moderately hard

Reported by Poulsbo City of · June 2025

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

The water in Poulsbo carries roughly 67 mg/L of dissolved calcium and magnesium, or 3.9 grains per gallon. That is moderately hard water. The number comes from Poulsbo City of, dated June 2025.

Poulsbo on the hardness scale, with nearby cities
060120180240300360+WA typical 36Mountlake Terrace: 14 mg/LMountlake Terrace 14Lake Forest Park: 30 mg/LLake Forest Park 30Shoreline: 31 mg/LShoreline 31Seattle: 31 mg/LSeattle 31Edmonds: 35 mg/LEdmonds 35Port Orchard: 39 mg/LPort Orchard 39Bremerton: 39 mg/LBremerton 39Tracyton: 49 mg/LTracyton 49Bainbridge Island: 70 mg/LBainbridge Island 70Silverdale: 80 mg/LSilverdale 80Poulsbo 67mg/L as calcium carbonate060120180240300360+WA 36Shoreline: 31 mg/LShoreline 31Edmonds: 35 mg/LEdmonds 35Port Orchard: 39 mg/LPort Orcha. 39Tracyton: 49 mg/LTracyton 49Bainbridge Island: 70 mg/LBainbridge. 70Silverdale: 80 mg/LSilverdale 8067 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Poulsbo sits 31 mg/L above the typical Washington figure of 36. Of the 10 nearest cities we track, 8 have softer water and 2 have harder. The range nearby runs from 14 mg/L in Mountlake Terrace to 80 in Silverdale.

What 67 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 Poulsbo

3 people × 75 gallons a day × 3.9 gpg = 875 grains a day. A 24,000-grain unit regenerates about every 27 days.

Size it for your household

EPA record for Poulsbo's water system

Poulsbo City of · PWSID WA5369150

No health-based violations since 2016

Serves about 18,400 people from groundwater.

Health-based
0
Monitoring or reporting
5
Open now
0

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 Poulsbo water hard?

Somewhat. It measures about 67 mg/L (3.9 grains per gallon), which the USGS classes as moderately hard.

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

About 3.9 gpg. One grain per gallon equals 17.1 mg/L, so 67 mg/L divided by 17.1 gives 3.9.

What size water softener do I need in Poulsbo?

For 3 people using 75 gallons each per day, 3.9 gpg works out to about 875 grains a day. A 24,000-grain softener covers that with a regeneration about every 27 days.

Has the Poulsbo water system had EPA violations?

EPA records show no health-based violations for Poulsbo City of since 2016. There were also 5 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 145 cities in Washington

Hardness data: TapWaterData US Water Hardness (utility report, June 20, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.