Water Quality Report · Updated October 07, 2026
WAILUKU
WAILUKU delivers tap water graded C (74/100) by TapWaterSafety.org. The utility serves approximately 74,511 residents in WAILUKU, Hawaii using surface water. 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. For questions, the utility can be reached at 808-270-7834.
Is WAILUKU tap water safe to drink?
WAILUKU delivers tap water that earns a grade of C (74/100) from TapWaterSafety.org — an average rating, with several contaminants above health guidelines but generally compliant with US legal limits.
The utility serves 74,511 residents in WAILUKU, drawing from surface water.
Public testing data identifies 16 contaminants in this water above EWG's health-based guidelines, including: Total trihalomethanes (TTHMs), Arsenic, Chromium (hexavalent), Dibromoacetic acid, Dibromochloromethane, Haloacetic acids (HAA9), Bromochloroacetic acid, Haloacetic acids (HAA5), Bromodichloromethane, Bromoform, Trichloroacetic acid, Nitrate and nitrite, Nitrate, Chloroform, Dichloroacetic acid, Vanadium. For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.
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.
Quick actions for WAILUKU residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for 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.
Contact WAILUKU
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Treatment Plant
Recommended water filters for WAILUKU
Filters matched to the specific contaminants in this 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.
Score breakdown
This utility's overall score of 74/100 breaks down across five weighted components. Read the full methodology →
Contaminants detected — international standards comparison
Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). 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 (4th ed.), California OEHHA PHGs, EWG Tap Water Database.
WAILUKU service area
This water system serves 1 community in Maui County, Hawaii. Click any city for its dedicated tap water quality page.
Find the right filter for WAILUKU water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.