Kaneohe Water Hardness & Quality Report (2026)
Water Hardness
3.5 grains per gallon
Source
groundwater
pH Level
7.6
neutral = 7.0
Lead
0.007 mg/L
✓ Below action level
TDS
185.2 mg/L
Est. Daily Cost
$0.16
energy & soap waste
Source: USGS Water Quality Portal · Updated 2026
0–60
mg/L
Soft
61–120
mg/L
Moderately Hard
121–180
mg/L
Hard
180+
mg/L
Very Hard
Appliance Damage Report
In Kaneohe, your appliances are currently losing 8% efficiency due to mineral buildup.
| Appliance | In Kaneohe | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 7.6 yrs | 8.5 yrs | -11% |
| Washing Machine | 11.4 yrs | 12 yrs | -5% |
| Water Heater | 13.2 yrs | 15 yrs | -12% |
Regional Water Comparison
How Kaneohe compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Kaneohe, Hawaii | 60.5 mg/L | 1.2 ppt | 🟡 Moderately Hard | groundwater |
| Kalihi Valley, Hawaii | 48 mg/L | 1.1 ppt | 🟢 Soft | groundwater |
| Kailua, Hawaii | 42 mg/L | 1 ppt | 🟢 Soft | groundwater |
| Nuuanu - Punchbowl, Hawaii | 67.5 mg/L | 1.3 ppt | 🟡 Moderately Hard | groundwater |
| Liliha - Kapalama, Hawaii | 16 mg/L | 0.6 ppt | 🟢 Soft | groundwater |
National Benchmark
How Kaneohe compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Kaneohe | 60.5 mg/L | 🟡 Low |
| USA National Avg | 150 mg/L | 🟠 Moderate |
| Badger Top Rated | 8.5 mg/L | 🟢 None |
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What Makes Kaneohe's Water Unique?
Local geology and source profile
Kaneohe, Hawaii, in Honolulu County on the island of Oahu — a major Windward Oahu community (Kaneohe is the primary town on Windward Oahu — the wetter, lush northeast side of Oahu facing Kaneohe Bay), home of the Hawaii Marine Corps Base Kaneohe Bay (MCB Hawaii — the only Marine Corps base in Hawaii, home of the Marine Corps Forces Pacific command; the base occupies the Mokapu Peninsula on Kaneohe Bay), adjacent to Kaneohe Bay (the largest sheltered body of water in Hawaii — a major reef ecosystem and recreational bay), a diverse Honolulu County community with a significant Native Hawaiian, Filipino-American, and Japanese-American population, and one of the most lush and green communities in Hawaii due to the Ko'olau Mountains catching trade wind rainfall — draws its municipal water supply via the Honolulu Board of Water Supply. Water hardness in Kaneohe measures 60.5 mg/L — classified as moderately soft.
Kaneohe's soft supply reflects the Windward Oahu Ko'olau Basalt aquifer's calcareous-poor volcanic geology. The Ko'olaupoko District basal lens aquifer at Kaneohe draws from: the Pliocene–Pleistocene Ko'olau Basalt (calcareous-poor tholeiitic basalt — the massive Ko'olau Shield Volcano that forms the windward side of Oahu; virtually no dissolved calcium carbonate in young Hawaiian basalt); and the trade wind orographic rainfall (calcareous-poor fresh precipitation). The calcareous-poor Ko'olau Basalt produces the soft 60.5 mg/L.
With hardness at 60.5 mg/L, Kaneohe residents enjoy moderately soft water. Honolulu Board of Water Supply consistently delivers water meeting all Hawaii DOH and EPA Safe Drinking Water Act requirements.
Geology & Source: Groundwater from the Windward Oahu basal lens aquifer (Ko'olaupoko District) via the Honolulu Board of Water Supply — the Honolulu County northeast Oahu Kaneohe Bay area (Pliocene–Pleistocene calcareous-poor Ko'olau Basalt — the calcareous-poor Windward Oahu volcanic aquifer; Kaneohe Valley basal groundwater supply); moderately soft supply at 60.5 mg/L in Honolulu County.