State Hub
Hawaii Water Quality
75
Utilities in database
1.5M
Residents served
18%
On private wells
2
Key contaminants tracked
Drinking Water in Hawaii
Hawaii has 75 community water systems serving approximately 1.5 million residents. Primary water sources include groundwater. The most commonly reported contaminants include disinfection byproducts, lead. 18% of Hawaii residents rely on private wells. DOH holds primary enforcement authority under the Safe Drinking Water Act.
Utilities in Hawaii
26–50 of 75Aliamanu
HI0000337 · 6,406 served
Kekaha-waimea
HI0000406 · 5,998 served
Hanapepe-eleele
HI0000404 · 5,592 served
Laie Water Company
HI0000325 · 5,577 served
Tripler Army Medical Cntr
HI0000346 · 5,555 served
Barbers Point
HI0000355 · 5,256 served
North Kohala
HI0000129 · 4,933 served
Waialee-sunset Beach
HI0000366 · 4,916 served
Haina
HI0000161 · 4,563 served
Hawaii Volcanoes Nat.park
HI0000146 · 4,201 served
Kapalua
HI0000204 · 4,200 served
Kamehameha Schools
HI0000319 · 4,000 served
Kaunakakai
HI0000234 · 3,702 served
Hawaiian Beaches
HI0000117 · 3,546 served
Lower Kula
HI0000247 · 3,522 served
The Queen's Medical Center
HI0000312 · 3,440 served
Kilauea
HI0000407 · 3,420 served
Lanai City
HI0000237 · 3,200 served
Waiohinu-naalehu
HI0000108 · 2,948 served
Kahuku
HI0000365 · 2,730 served
Anahola
HI0000401 · 2,473 served
Hoolehua
HI0000230 · 2,400 served
Papaikou
HI0000107 · 2,203 served
Kaupulehu
HI0000163 · 1,945 served
Lalamilo
HI0000160 · 1,895 served
Key Contaminant Concerns in Hawaii
Lead
Lead is a naturally occurring heavy metal that was widely used in plumbing infrastructure until it was banned for new installations in 1986. An estimated 9.2 million lead service lines still connect homes to public water mains across the United States, along with millions of homes with lead solder in their internal plumbing.
DBPs
When utilities add chlorine to water to kill pathogens, it reacts with dissolved organic matter — leaves, algae, soil — to produce disinfection byproducts (DBPs). Over 600 DBPs have been identified. The EPA regulates two groups: total trihalomethanes (TTHMs, including chloroform) and haloacetic acids (HAA5). DBP levels tend to be highest in surface water systems and in warm months when organic matter is elevated.
Hawaii Water FAQs
Quick Links
Data source: Utility data from EPA SDWIS. 75 active community water systems ingested. CCR contaminant data ingestion in progress.
Last updated: 2026-04-22