Koolauloa Water Hardness & Quality Report (2026)
Water Hardness
2.1 grains per gallon
Source
groundwater
pH Level
7.3
neutral = 7.0
Lead
0.004 mg/L
✓ Below action level
TDS
92.8 mg/L
Est. Daily Cost
$0.09
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 Koolauloa, your appliances are currently losing 5% efficiency due to mineral buildup.
| Appliance | In Koolauloa | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 8.4 yrs | 8.5 yrs | -1% |
| Washing Machine | 12.3 yrs | 12 yrs | — |
| Water Heater | 14.2 yrs | 15 yrs | -5% |
Regional Water Comparison
How Koolauloa compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Koolauloa, Hawaii | 35.5 mg/L | 0.9 ppt | 🟢 Soft | groundwater |
| Mililani Mauka / Launani Valley, Hawaii | 35 mg/L | 0.9 ppt | 🟢 Soft | groundwater |
| Wahiawa, Hawaii | 77.5 mg/L | 1.5 ppt | 🟡 Moderately Hard | groundwater |
| Schofield Barracks, Hawaii | 76.5 mg/L | 1.5 ppt | 🟡 Moderately Hard | groundwater |
| Mililani Town, Hawaii | 67.5 mg/L | 1.3 ppt | 🟡 Moderately Hard | groundwater |
National Benchmark
How Koolauloa compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Koolauloa | 35.5 mg/L | 🟢 None |
| USA National Avg | 150 mg/L | 🟠 Moderate |
| Badger Top Rated | 8.5 mg/L | 🟢 None |
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What Makes Koolauloa's Water Unique?
Local geology and source profile
Koolaupoko (Ko'olaupoko), Hawaii, in Honolulu County — an O'ahu Honolulu County community on the windward side (Ko'olau side) of O'ahu, adjacent to the Ko'olau Mountains — receives its water from the City and County of Honolulu Board of Water Supply, drawing from local Ko'olau Range volcanic aquifer wells and springs (Honolulu County) through the windward O'ahu water distribution system.
The very soft 35.5 mg/L hardness and TDS of 92.8 mg/L reflect the Hawaiian volcanic aquifer's characteristic soft water — basalt is nearly insoluble and the high rainfall recharge rate through the Ko'olau Mountains produces low-mineral, fresh groundwater. The Ko'olau Range volcanic aquifer is developed in Pleistocene Ko'olau Basalt (Hawaiian Tholeiitic basalt — nearly insoluble silica, minimal calcium carbonate), with some minor Pleistocene reef carbonate input from coastal caprock (minimal hardness contributor). The dominant tholeiitic basalt produces the very soft Hawaiian windward supply.
At 35.5 mg/L, Koolaupoko's water is very soft — essentially no scale forms, soap lathers abundantly, and appliances maintain excellent efficiency. Annual descaling is sufficient. The PFAS level of 0.9 ppt is among the lowest in this dataset — the Ko'olau windward O'ahu corridor has no major military AFFF sources directly adjacent, and the isolated Pacific island volcanic aquifer system has essentially pristine PFAS levels.
Geology & Source: Koolaupoko in Honolulu County draws from the Board of Water Supply Honolulu on local basalt aquifers (Honolulu County, northeast Oahu) — the Ko'olau Range volcanic aquifer is developed in Pleistocene Ko'olau Basalt (Tholeiitic basalt — insoluble) — Hawaii Honolulu County Ko'olau basalt aquifer produces very soft water at 35.5 mg/L with TDS 92.8 mg/L in this Honolulu County Hawaii community.