Hard water in Pasco, WA
County estimate from 96 water samples in Franklin County · July 2026
- WA typical
- 36 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 32k grain
- Data
- County estimate
Water samples from around Pasco put hardness at about 268 mg/L (15.7 gpg), which would be very hard on the USGS scale. Treat this as a rough guide: it is the median of 96 samples taken across Franklin County, mostly wells and streams, not a test of Pasco's treated tap water. One more reason for caution: EPA lists Pasco's water system as using surface water, which is often softer than the wells behind the county figure.
At 268 mg/L, Pasco is 232 mg/L above the typical Washington figure of 36. None of the 10 nearest cities we track has harder water. The range nearby runs from 33 mg/L in West Richland to 208 in Grandview.
What 268 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 268 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 × 15.7 gpg = 3,532 grains a day. A 32,000-grain unit regenerates about every 9 days.
EPA record for Pasco's water system
No health-based violations since 2016
Serves about 115,102 people from surface water.
- Health-based
- 0
- Monitoring or reporting
- 24
- Open now
- 0
EPA lists this system as serving Pasco.
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 Pasco water hard?
Yes. It measures about 268 mg/L (15.7 grains per gallon), which the USGS classes as very hard.
What is the water hardness in Pasco in grains per gallon?
About 15.7 gpg. One grain per gallon equals 17.1 mg/L, so 268 mg/L divided by 17.1 gives 15.7.
What size water softener do I need in Pasco?
For 3 people using 75 gallons each per day, 15.7 gpg works out to about 3,532 grains a day. A 32,000-grain softener covers that with a regeneration about every 9 days.
Has the Pasco water system had EPA violations?
EPA records show no health-based violations for Pasco Water Department since 2016. There were also 24 monitoring or reporting violations, which are about late or missing tests and notices.
Nearby cities
- Kennewick96 mg/LModerately hard
- Finley96 mg/LModerately hard
- Richland89 mg/LModerately hard
- West Richland33 mg/LSoft
- Grandview208 mg/LVery hard
- Othello33 mg/LSoft
- Walla Walla39 mg/LSoft
- Toppenish63 mg/LModerately hard
- Moses Lake168 mg/LHard
- Terrace Heights88 mg/LModerately hard
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.