Is Wailuku Tap Water Safe? Quality Report

Water source: Surface water
Ownership: Local government
Counties served: Maui

Compliance record

Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.

health-based violations

violations on file

still open

Violation	Type	Status	Period
MCL	Health-based	Archived	2000-10-01 → 2000-10-31
MCL	Health-based	Archived	2000-10-01 → 2000-10-31
MCL	Health-based	Archived	2000-10-01 → 2000-10-31
MCL	Health-based	Archived	2000-10-01 → 2000-10-31
MCL	Health-based	Archived	2000-10-01 → 2000-10-31
MCL	Health-based	Archived	2000-10-01 → 2000-10-31
MCL	Health-based	Archived	1991-03-01 → 1991-03-31
MCL	Health-based	Archived	1991-03-01 → 1991-03-31
MCL	Health-based	Archived	1991-03-01 → 1991-03-31
MCL	Health-based	Archived	1991-03-01 → 1991-03-31

Other contaminants detected

Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the 95th percentile of this system's samples — over 100% is worth reading, but is not by itself a violation. Where a single sample came in higher than that percentile, it is noted under the bar. Formal violations are listed separately.

Contaminant	Level vs EPA limit	Detection rate	Source	Period
Nitrate	2990 µg/L 30% of the EPA limit 10000 µg/L worst single sample: 3200 µg/L	292/294	SYR4	2012–2019
TTHM	26.9 µg/L 34% of the EPA limit 80 µg/L worst single sample: 35 µg/L	203/238	SYR4	2012–2019
Bromoform	18 µg/L No EPA limit set worst single sample: 24 µg/L	199/238	SYR4	2012–2019
Dibromochloromethane	7 µg/L No EPA limit set worst single sample: 9.2 µg/L	198/238	SYR4	2012–2019
Bromodichloromethane	2.8 µg/L No EPA limit set worst single sample: 9 µg/L	159/238	SYR4	2012–2019
Nitrate-Nitrite	2980 µg/L 30% of the EPA limit 10000 µg/L worst single sample: 3200 µg/L	141/142	SYR4	2012–2019
Dibromoacetic Acid	3.56 µg/L No EPA limit set worst single sample: 3.9 µg/L	85/188	SYR4	2012–2019
Chloroform	2.775 µg/L No EPA limit set worst single sample: 20 µg/L	66/238	SYR4	2012–2019
Fluoride	335 µg/L 8.4% of the EPA limit 4000 µg/L worst single sample: 480 µg/L	50/138	SYR4	2012–2019
Total Haloacetic Acids (HAA5)	5.5 µg/L 9.2% of the EPA limit 60 µg/L worst single sample: 18 µg/L	46/188	SYR4	2012–2019
Barium	11.425 µg/L 0.6% of the EPA limit 2000 µg/L worst single sample: 14 µg/L	32/43	SYR4	2012–2019
Chromium	4.4 µg/L 4.4% of the EPA limit 100 µg/L worst single sample: 4.7 µg/L	26/43	SYR4	2012–2019
Copper	46.2 µg/L 3.6% of the EPA limit 1300 µg/L worst single sample: 50 µg/L	20/43	SYR4	2012–2019
Dichloroacetic Acid	3.46 µg/L No EPA limit set worst single sample: 9.3 µg/L	17/188	SYR4	2012–2019
Lead	0.0 mg/L 0% of the EPA limit 0.0150 mg/L	15/15	LCR	2018
Trichloroacetic Acid	5.88 µg/L No EPA limit set worst single sample: 8.6 µg/L	9/188	SYR4	2012–2019
Lead	4.5 µg/L 30% of the EPA limit 15 µg/L worst single sample: 5.5 µg/L	6/43	SYR4	2012–2019
Selenium	11.51 µg/L 23% of the EPA limit 50 µg/L worst single sample: 12 µg/L	3/43	SYR4	2012–2019
Di(2-ethylhexyl) Phthalate	1.5 µg/L 25% of the EPA limit 6 µg/L	1/56	SYR4	2012–2018
Gross Alpha, Excl. Radon And U	2.9 pCi/L 19% of the EPA limit 15 pCi/L	1/17	SYR4	2012–2018
Gross Beta Particle Activity	3.4 pCi/L No EPA limit set	1/19	SYR4	2012–2018

93 contaminants tested, none detected

1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-DIBROMO-3-CHLOROPROPANE1,2-Dichloroethane1,2-Dichloropropane11Cl-PF3OUdS2,3,7,8-TCDD2,4,5-TP2,4-D4:2 Fts6:2 Fts8:2 Fts9Cl-PF3ONSAdonaAntimony, TotalArsenicAsbestosAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalChlorobenzeneCyanideCadmiumCarbofuranCarbon TetrachlorideChlordaneCombined Radium (-226 And -228)Combined UraniumDichloromethaneDalaponDi(2-ethylhexyl) AdipateDinosebDiquatEthylene DibromideEndothallEndrinEthylbenzeneGlyphosateHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorMonobromoacetic AcidMonochloroacetic AcidNetfosaaNfdhaNmefosaaNitriteOxamylPfbaPFBSPfdaPfdoaPfeesaPfhpaPfhpsPfhxaPFHXSPfmbaPfmpaPFNAPFOAPFOSPfpeaPfpesPftaPftrdaPfunaPentachlorophenolPicloramSimazineStyreneTetrachloroethyleneThallium, TotalTolueneTotal Polychlorinated Biphenyls (PCB)ToxapheneTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneLithiumO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact: PEARSON, JEFF
Phone: 808-270-7834
Email: [email protected]

Frequently asked questions about Wailuku

Is Wailuku tap water safe to drink?

EPA monitoring detected 21 contaminants in Wailuku's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.

What contaminants were detected in Wailuku's water?

EPA monitoring detected Nitrate, TTHM, Bromoform, Dibromochloromethane, Bromodichloromethane, and others. The full list with the level and data source for each is above.

How many people does Wailuku serve?

Wailuku reports serving 74,511 people in Hawaii, per its EPA record.

Has Wailuku had any water quality violations?

The EPA has 53 violations on file for Wailuku, of which 10 are health-based (a contaminant limit or required treatment was breached) and 0 remain open. The rest are monitoring or reporting failures.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.