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Water Hardness in 96738

Waikoloa, Hawaii · Hawaii County

150 PPM
8.8 GPG
Moderately Hard
0Soft60120180300+
Verified - Annual Water Quality Report

Dataset updated March 9, 2026Matched to 8 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 8 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
5 verified treated-water sources
8 matched systems total for this ZIP; treated-water reports are prioritized when available.
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 96738

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.

8 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.
Hilo
HI0000101
Soft
15 PPMgroundwater39,477 servedVerified - Annual Water Quality Report
Source water: 1023 PPM
North Kona
HI0000131
Soft
15 PPMgroundwater29,581 servedVerified - Annual Water Quality Report
Source water: 1023 PPM
Waikoloa
HI0000135
Soft
15 PPMgroundwater12,100 servedVerified - Annual Water Quality Report
Source water: 1023 PPM
Kaanapali
HI0000205
Very Hard
1023 PPMgroundwater8,000 servedEstimated - Nearby Data
Barbers Point
HI0000355
Very Hard
1023 PPMgroundwater5,256 servedEstimated - Nearby Data
Showing the first 5 systems. Expand to review all matched systems.

Nearby Zip Codes

9674020967432896725159675515967271596750159677623

What This Means For You

Use this ZIP reading as a local planning estimate, not a final treatment specification. Hardness can vary by utility zone, seasonal blend, private well, and building plumbing. Confirm your tap reading with a utility report or home hardness test before sizing equipment.

MethodologyData sourcesHow to test your water

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 Waikoloa, HI (96738).

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Frequently Asked Questions

Is the water hard in Waikoloa, HI (96738)?

The average water hardness in 96738 is 150 PPM (8.8 GPG), which is classified as moderately hard.

Do I need a water softener in 96738?

With hardness of 150 PPM, a water softener is worth considering for homes in 96738.

Is hard water in 96738 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 96738?

Zip code 96738 in Waikoloa, Hawaii is served by 8 water systems.

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