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Water Hardness in 96720

Hilo, Hawaii · Hawaii County

15 PPM
0.9 GPG
Soft
0Soft60120180300+
Verified — Annual Water Quality Report

Dataset updated March 9, 2026Matched to 20 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 20 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
20 verified treated-water sources
20 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 96720

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.

20 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
South Kohala
HI0000130
Soft
15 PPMsurface water9,612 servedVerified — Annual Water Quality Report
Source water: 1023 PPM
South Kona
HI0000132
Soft
15 PPMgroundwater6,512 servedVerified — Annual Water Quality Report
Source water: 1023 PPM
Showing the first 5 systems. Expand to review all matched systems.

Nearby Zip Codes

967711596781409676015967851596710159674915967833296728229677315967783896780159677415

What This Means For You

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

Your Water Is Soft

Your water hardness is in the soft range. You likely don't need a water softener. Enjoy your naturally soft 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 Hilo, HI (96720).

Submit Your Data

Frequently Asked Questions

Is the water hard in Hilo, HI (96720)?

The average water hardness in 96720 is 15 PPM (0.9 GPG), which is classified as soft.

Do I need a water softener in 96720?

At 15 PPM, your water is relatively soft. A water softener is generally not necessary.

Is hard water in 96720 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 96720?

Zip code 96720 in Hilo, Hawaii is served by 20 water systems.

Learn More About Your Water

Water Hardness Scale: PPM and GPG Chart

Use the USGS water hardness scale to compare PPM, GPG, and mg/L levels from soft to very hard water.

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How to Test Water Hardness at Home

Compare free lookups, soap tests, test strips, liquid drop kits, and lab tests for measuring water hardness.

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