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Tap water quality report

Hilo, HI

EPA monitoring detected 12 contaminants across the 1 water supplier serving Hilo. A detection doesn't automatically mean the water is unsafe — see the highest level found for each below, with its EPA source and period.

1
water supplier
39,477
people served
12
contaminants found
Hawaii rankings Lead in Hawaii PFAS in Hawaii

What was found in Hilo's water

The highest level seen across the city's suppliers, the EPA limit for each, and where the figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
Nitrate
420 µg/L 4.2%
of the EPA limit 10000 µg/L
 1/1 SYR4
Nitrate-Nitrite
420 µg/L 4.2%
of the EPA limit 10000 µg/L
 1/1 SYR4
Fluoride
240 µg/L 6%
of the EPA limit 4000 µg/L
 1/1 SYR4
Copper
207 µg/L 16%
of the EPA limit 1300 µg/L
 1/1 SYR4
TTHM
1.9 µg/L 2.4%
of the EPA limit 80 µg/L
 1/1 SYR4
Chromium
1.3 µg/L 1.3%
of the EPA limit 100 µg/L
 1/1 SYR4
Total Haloacetic Acids (HAA5)
1.1 µg/L 1.8%
of the EPA limit 60 µg/L
 1/1 SYR4
Trichloroacetic Acid
1.1 µg/L
No EPA limit set
 1/1 SYR4
Dibromochloromethane
0.8100 µg/L
No EPA limit set
 1/1 SYR4
Bromoform
0.5700 µg/L
No EPA limit set
 1/1 SYR4
Bromodichloromethane
0.5200 µg/L
No EPA limit set
 1/1 SYR4
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
 1/1 LCR
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 single worst sample on record — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately. These are the utilities' own EPA-reported results, not a city-wide average. A detection means the lab measured the substance — it isn't the same as exceeding a legal limit. Hover a source tag to see the EPA program and years behind each figure.

Water suppliers serving Hilo

SupplierPopulation served
HILO 39,477

Frequently asked questions about Hilo tap water

Is Hilo tap water safe to drink?

EPA testing detected 12 contaminants in the water serving Hilo. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.

How many water suppliers serve Hilo?

1 public water supplier report drinking-water monitoring for Hilo, Hawaii to the EPA. Each is listed above with its population served.

What contaminants are in Hilo's water?

The contaminants EPA monitoring detected in Hilo include Nitrate, Nitrate-Nitrite, Fluoride, Copper, TTHM. The full list, with the highest level found and the data source, is in the table above.

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.