Water Quality Report · Updated October 07, 2026
HNL-WINDWARD-PEARL HARBOR
HNL-WINDWARD-PEARL HARBOR delivers tap water graded A (85/100) by TapWaterSafety.org. The utility serves approximately 631,389 residents in HONOLULU-WINDWARD-PEARLHARBOR, Hawaii using groundwater. The most significant water quality concerns are: Chromium (hexavalent) significantly above health guideline; Perfluorohexane sulfonate (PFHXS) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline. For questions, the utility can be reached at 808-748-5080.
Is HONOLULU-WINDWARD-PEARLHARBOR tap water safe to drink?
HNL-WINDWARD-PEARL HARBOR delivers tap water that earns a grade of A (85/100) from TapWaterSafety.org — an excellent rating reflecting minimal contamination and full compliance with health guidelines.
The utility serves 631,389 residents in HONOLULU-WINDWARD-PEARLHARBOR, drawing from groundwater.
Public testing data identifies 11 contaminants in this water above EWG's health-based guidelines, including: Chromium (hexavalent), Perfluorohexane sulfonate (PFHXS), Total trihalomethanes (TTHMs), Haloacetic acids (HAA9), Dibromoacetic acid, Bromochloroacetic acid, 1,2,3-Trichloropropane, Bromoform, Nitrate and nitrite, Nitrate, Haloacetic acids (HAA5). 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 HNL-WINDWARD-PEARL HARBOR (system ID HI0000331) 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 HONOLULU-WINDWARD-PEARLHARBOR residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for HNL-WINDWARD-PEARL HARBOR.
Chromium (hexavalent) significantly above health guideline
Moderate concernChromium (hexavalent) detected at 1.78 ppb, 89x above the EWG health guideline of 0.02 ppb.
Perfluorohexane sulfonate (PFHXS) significantly above health guideline
Moderate concernPerfluorohexane sulfonate (PFHXS) detected at 0.034 ppt, 34x above the EWG health guideline of 0.001 ppt.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 3.76 ppb, 25x above the EWG health guideline of 0.15 ppb.
Contact HNL-WINDWARD-PEARL HARBOR
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 HONOLULU-WINDWARD-PEARLHARBOR
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.
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 85/100 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 |
|---|---|---|---|---|---|---|---|---|
| Chromium (hexavalent) Heavy metal |
1.78 ppb | 0.02 | — | — | — | — | — | 89× over |
| Perfluorohexane sulfonate (PFHXS) PFAS |
0.034 ppt | 0.001 | 10.0 | — | — | — | — | 34× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
3.76 ppb | 0.15 | 80.0 | 100 | — | — | — | 25× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
0.918 ppb | 0.06 | — | — | — | — | — | 15× over |
| Dibromoacetic acid Disinfection byproduct |
0.418 ppb | 0.03 | — | — | — | — | — | 14× over |
| Bromochloroacetic acid Disinfection byproduct |
0.136 ppb | 0.02 | — | — | — | — | — | 6.8× over |
| 1,2,3-Trichloropropane Other |
0.00395 ppb | 0.0007 | — | — | — | — | — | 5.6× over |
| Bromoform Disinfection byproduct |
2.77 ppb | 0.5 | — | — | — | — | — | 5.5× over |
| Nitrate and nitrite Inorganic |
0.414 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 3.0× over |
| Nitrate Inorganic |
0.41 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 2.9× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
0.242 ppb | 0.1 | 60.0 | 60 | — | — | — | 2.4× over |
| Trichloroacetic acid Disinfection byproduct |
0.0661 ppb | 0.1 | — | — | — | — | — | Below guideline |
| Dibromochloromethane Disinfection byproduct |
0.0658 ppb | 0.1 | — | — | — | — | — | Below guideline |
| Radium, combined (-226 and -228) Radiological |
0.03 pCi/L | 0.05 | 5.0 | — | — | — | — | Below guideline |
| Vanadium Other |
11.3 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Dichloroacetic acid Disinfection byproduct |
0.0968 ppb | 0.2 | — | — | — | — | — | Below guideline |
| Chlordane Other |
0.0137 ppb | 0.03 | 2.0 | — | — | — | — | Below guideline |
| Chlorate Disinfection byproduct |
29.1 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Heptachlor epoxide Other |
0.000546 ppb | 0.006 | 0.2 | — | — | — | — | Below guideline |
| Barium Heavy metal |
5.02 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Manganese Heavy metal |
0.106 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Strontium Radiological |
0.107 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| 1-Butanol Other |
0.378 ppb | — | — | — | — | — | — | Below guideline |
| Chromium (total) Heavy metal |
1.63 ppb | — | 100.0 | — | — | — | — | Below guideline |
| Dieldrin Other |
0.0114 ppb | — | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.00981 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.
HNL-WINDWARD-PEARL HARBOR service area
This water system serves 1 community in Honolulu County, Hawaii. Click any city for its dedicated tap water quality page.
Find the right filter for HONOLULU-WINDWARD-PEARLHARBOR water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.