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Water Hardness in Lewiston, CA

California · 1 zip codes · 3 matched water systems

129 PPM
7.5 GPG
Moderately Hard
0Soft60120180300+
High Confidence — USGS Monitoring

Dataset updated March 9, 20263 matched water systems in the city rollupIndividual systems and ZIPs can differ. Methodology

Source context

How this city reading is built

This city reading is a weighted rollup across 3 matched water systems and 1 ZIP code. Citywide readings are useful for comparison, but individual utility zones and ZIPs can differ.

Source basis
3 USGS-backed sources
3 matched systems total for this city; 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 in Lewiston

These systems are matched to Lewiston, CA. Citywide readings are useful for comparison, but the system serving a specific address may differ from the city average.

3 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.
Treasure Creek Woods Mwc
CA5301101
Moderately Hard
129 PPMgroundwater131 servedHigh Confidence — USGS Monitoring
Lakeshore Villa Mutual Water Co
CA4500008
Moderately Hard
129 PPMgroundwater88 servedHigh Confidence — USGS Monitoring
Bucktail Mutual Water Company
CA5301001
Moderately Hard
129 PPMgroundwater42 servedHigh Confidence — USGS Monitoring

Zip Codes in Lewiston, CA

What This Means For You

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

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If you've tested your water or have your utility's CCR report, share your reading to help us improve accuracy for Lewiston, CA.

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Frequently Asked Questions

How hard is the water in Lewiston, CA?

The citywide weighted average water hardness in Lewiston, CA is 129 PPM (7.5 GPG), classified as moderately hard. This is based on 3 matched water systems.

Do I need a water softener in Lewiston, CA?

With a citywide average hardness of 129 PPM, a water softener is worth considering for homes in Lewiston. Confirm your tap reading before sizing equipment.

Is hard water in Lewiston, CA 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 Lewiston, CA?

Lewiston, California is served by 3 matched water systems across 1 zip code.

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