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
51–75 of 75Pahoa
HI0000111 · 1,885 served
Dillingham Airfield
HI0000338 · 1,800 served
Pepeekeo
HI0000106 · 1,450 served
Hawaiian Shores
HI0000156 · 1,360 served
Hana
HI0000217 · 1,284 served
Gay & Robinson
HI0000417 · 1,271 served
Pahala
HI0000109 · 1,226 served
Haleakala National Park
HI0000222 · 1,200 served
Pacific Missile Range Facility
HI0000430 · 1,200 served
Laupahoehoe-kapehu
HI0000102 · 1,169 served
Ualapue
HI0000233 · 1,119 served
Hoku'ula Water System
HI0000267 · 1,000 served
Hawaiian Ocean View Estates
HI0000169 · 1,000 served
Maunaloa-kaluakoi
HI0000231 · 1,000 served
Kohala Ranch Water Co.
HI0000151 · 850 served
Haena-wainiha
HI0000415 · 833 served
Hana Water Systems - South
HI0000201 · 816 served
Paauilo
HI0000134 · 716 served
Kunia Village
HI0000303 · 650 served
Honomu
HI0000105 · 645 served
Mahanalua Nui Subdivison
HI0000251 · 606 served
Camp Stover
HI0000354 · 595 served
Kawela Plantation
HI0000248 · 553 served
Hanalei
HI0000403 · 500 served
Kualapuu
HI0000229 · 500 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
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Data source: Utility data from EPA SDWIS. 75 active community water systems ingested. CCR contaminant data ingestion in progress.
Last updated: 2026-04-22