Tap Water Quality Report
Tap water quality in WAILUKU, Hawaii
Tap water in WAILUKU, Hawaii receives a grade of C (74/100) from TapWaterSafety.org. It's served by WAILUKU. The most significant water quality concerns are: Total trihalomethanes (TTHMs) significantly above health guideline; Arsenic significantly above health guideline; Chromium (hexavalent) significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in WAILUKU's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving WAILUKU.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 16.2 ppb, 108x above the EWG health guideline of 0.15 ppb.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 0.315 ppb, 79x above the EWG health guideline of 0.004 ppb.
Chromium (hexavalent) significantly above health guideline
Moderate concernChromium (hexavalent) detected at 1.51 ppb, 75x above the EWG health guideline of 0.02 ppb.
EPA compliance record
Official U.S. EPA records for WAILUKU (system ID HI0000212) for the last 3 years. Checked 2026-10-07.
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Recommended filters for WAILUKU
Filters matched to the specific contaminants in WAILUKU's water supply.
Carbon filter certified for VOCs (NSF/ANSI 53)
$180-$599Activated carbon is effective for disinfection byproducts like TTHM. Look for NSF/ANSI 53 VOC or chloroform reduction.
Reverse osmosis certified for arsenic (NSF/ANSI 58)
$429-$599Reverse osmosis certified under NSF/ANSI 58 for arsenic is the most reliable home option.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
All contaminants detected in WAILUKU's tap water
Every contaminant identified, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal. Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Total trihalomethanes (TTHMs) Disinfection byproduct |
16.2 ppb | 0.15 | 80.0 | 100 | — | — | — | 108× over |
| Arsenic Heavy metal |
0.315 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 79× over |
| Chromium (hexavalent) Heavy metal |
1.51 ppb | 0.02 | — | — | — | — | — | 75× over |
| Dibromoacetic acid Disinfection byproduct |
2.05 ppb | 0.03 | — | — | — | — | — | 68× over |
| Dibromochloromethane Disinfection byproduct |
4.62 ppb | 0.1 | — | — | — | — | — | 46× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
2.72 ppb | 0.06 | — | — | — | — | — | 45× over |
| Bromochloroacetic acid Disinfection byproduct |
0.705 ppb | 0.02 | — | — | — | — | — | 35× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
3.29 ppb | 0.1 | 60.0 | 60 | — | — | — | 33× over |
| Bromodichloromethane Disinfection byproduct |
1.9 ppb | 0.06 | — | — | — | — | — | 32× over |
| Bromoform Disinfection byproduct |
8.15 ppb | 0.5 | — | — | — | — | — | 16× over |
| Trichloroacetic acid Disinfection byproduct |
0.904 ppb | 0.1 | — | — | — | — | — | 9.0× over |
| Nitrate and nitrite Inorganic |
0.572 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 4.1× over |
| Nitrate Inorganic |
0.554 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 4.0× over |
| Chloroform Disinfection byproduct |
1.29 ppb | 0.4 | — | — | — | — | — | 3.2× over |
| Dichloroacetic acid Disinfection byproduct |
0.648 ppb | 0.2 | — | — | — | — | — | 3.2× over |
| Vanadium Other |
21.6 ppb | 21.0 | — | — | — | — | — | 1.0× over |
| Chlorate Disinfection byproduct |
24.4 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Selenium Heavy metal |
1.53 ppb | 30.0 | 50.0 | 20 | 40 | 30 | — | Below guideline |
| 1,4-Dioxane Semi-volatile organic compound |
0.0147 ppb | 0.35 | — | — | 50 | 1 | — | Below guideline |
| Barium Heavy metal |
4.66 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Manganese Heavy metal |
0.118 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Monobromoacetic acid Disinfection byproduct |
0.0208 ppb | 25.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.117 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Chromium (total) Heavy metal |
1.51 ppb | — | 100.0 | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.0458 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines, California OEHHA PHGs, EWG Tap Water Database.
Treatment plant contact info
For service issues, water quality concerns, or to request a Consumer Confidence Report from WAILUKU.