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Water Hardness in 99349

Royal City, Washington · Grant County

237 PPM
13.8 GPG
Hard
0Soft60120180300+
High Confidence — USGS Monitoring

Dataset updated March 9, 2026Matched to 7 water systemsTap readings can vary by utility zone, treatment, and plumbing. Methodology

Source context

How this ZIP reading is built

This ZIP reading is built from 7 matched water systems. When more than one system is matched, the displayed value is weighted toward larger known service populations when that data is available.

Source basis
7 USGS-backed sources
7 matched systems total for this ZIP; USGS monitoring is used where treated-water reports are unavailable.
Water source profile
Primarily groundwater
Groundwater commonly picks up calcium and magnesium after contact with rock and soil. This profile is weighted by known population served across matched systems.
Data recency
March 9, 2026
Dataset rebuilt March 9, 2026; individual utility reporting years can vary.

Hardness is a mineral-content reading, not a drinking-water safety rating. Use it for scale, appliance, and softener decisions; check your utility report or test your tap before sizing treatment equipment. See how we calculate local readings.

Water Systems Serving 99349

These are the systems matched to this ZIP code. The displayed ZIP value is weighted toward larger known service populations when population data is available.

7 water systems
PWSID is the public water system identifier. Data Source shows whether the hardness value comes from a treated-water report, USGS monitoring, or a local estimate; source year is shown when available.
Moses Lake City Of
WA5356300
Hard
196 PPMgroundwater32,428 servedHigh Confidence — USGS Monitoring
Mattawa City Of
WA5352000
Very Hard
335 PPMgroundwater5,015 servedHigh Confidence — USGS Monitoring
Royal City Water
WA5374700
Very Hard
335 PPMgroundwater3,389 servedHigh Confidence — USGS Monitoring
Desert Aire Owner Assn
WA5319056
Very Hard
335 PPMgroundwater2,856 servedHigh Confidence — USGS Monitoring
George City Of
WA5327395
Very Hard
412 PPMgroundwater1,035 servedHigh Confidence — USGS Monitoring
Showing the first 5 systems. Expand to review all matched systems.

Nearby Zip Codes

What This Means For You

Recommendations are based on the displayed ZIP hardness reading. Confirm your tap reading before sizing or buying treatment equipment.

Know your water hardness?

If you've tested your water or have your utility's CCR report, share your reading to help us improve accuracy for Royal City, WA (99349).

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Frequently Asked Questions

Is the water hard in Royal City, WA (99349)?

The average water hardness in 99349 is 237 PPM (13.8 GPG), which is classified as hard.

Do I need a water softener in 99349?

With hardness of 237 PPM, a water softener is recommended for homes in 99349.

Is hard water in 99349 safe to drink?

Water hardness itself is a mineral-content reading, not a drinking-water safety rating. Calcium and magnesium are naturally occurring minerals, but you should check your utility's Consumer Confidence Report for contaminant and compliance information.

How many water systems serve 99349?

Zip code 99349 in Royal City, Washington is served by 7 water systems.

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