Water Quality: Hilo, HI
24 water systems • 118,171 people served
Multiple Health ViolationsWater Quality Summary
Hilo is served by 24 public water systems with a combined service population of 118,171 people, and has 10 EPA Safe Drinking Water Act violations on record. Critically, 4 of those are health-based violations, meaning one or more contaminants were detected above EPA-established safe levels — a serious public health concern. Hilo's violation count is 76% above the national average for Hawaii. Contaminants associated with violations include Disinfection Byproducts, Fecal Coliform.
Contaminants Found
Broad category of chemicals formed during disinfection, associated with increased cancer risk and adverse reproductive effects.
Common source: Reaction of disinfectants (chlorine, ozone, chloramines) with organic matter
Indicates direct fecal contamination; associated with diarrhea, cramps, nausea, and potential severe illness.
Common source: Human and animal fecal waste
EPA limit: Zero tolerance (any positive triggers violations)
Water Systems Serving Hilo
| System Name | PWSID | Source | Population | Violations |
|---|---|---|---|---|
| HILO | HI0000101 | Groundwater | 39,477 | 1 |
| NORTH KONA | HI0000131 | Groundwater | 29,581 | 1 |
| SOUTH KOHALA | HI0000130 | Surface Water | 9,612 | 2 |
| SOUTH KONA | HI0000132 | Groundwater | 6,512 | 0 |
| OLAA-MOUNTAIN VIEW | HI0000112 | Groundwater | 6,467 | 0 |
| NORTH KOHALA | HI0000129 | Groundwater | 4,933 | 0 |
| HAINA | HI0000161 | Groundwater | 4,563 | 0 |
| WAIOHINU-NAALEHU | HI0000108 | Groundwater | 2,948 | 0 |
| PAPAIKOU | HI0000107 | Groundwater | 2,203 | 0 |
| LALAMILO | HI0000160 | Groundwater | 1,895 | 0 |
| PAHOA | HI0000111 | Groundwater | 1,885 | 0 |
| PEPEEKEO | HI0000106 | Groundwater | 1,450 | 0 |
| PAHALA | HI0000109 | Groundwater | 1,226 | 1 |
| LAUPAHOEHOE-KAPEHU | HI0000102 | Groundwater | 1,169 | 0 |
| HAWAIIAN OCEAN VIEW ESTATES | HI0000169 | Groundwater | 1,000 | 3 |
| PAAUILO | HI0000134 | Groundwater | 716 | 0 |
| HONOMU | HI0000105 | Groundwater | 645 | 0 |
| KUKUIHAELE | HI0000133 | Groundwater | 483 | 1 |
| HAKALAU-WAILEA | HI0000154 | Groundwater | 402 | 0 |
| KALAPANA | HI0000110 | Groundwater | 275 | 0 |
| OOKALA (DWS) | HI0000104 | Groundwater | 264 | 0 |
| NIULII | HI0000139 | Groundwater | 254 | 0 |
| NINOLE | HI0000103 | Groundwater | 151 | 0 |
| PEPEEKEO WATER ASSOCIATION | HI0000167 | Groundwater | 60 | 1 |
Concerned About Your Water?
A home water filter can remove common contaminants. NSF-certified filters are tested against EPA standards.
Consider a reverse osmosis system for comprehensive filtration or a carbon filter for basic improvement.
Other Cities in Hawaii
Data Sources
Drinking water violation data from the EPA Safe Drinking Water Information System (SDWIS). Data includes all recorded violations for active community water systems.