State Hub
Hawaii Water Quality
75
Utilities in database
1.5M
Residents served
0
With open violations
43
PFAS monitored
Quick Answer
Hawaii public drinking water is served by 75 EPA-tracked water systems, providing service to approximately 1.5 million residents through public utilities. No open health-based violations are currently recorded across tracked systems in the EPA federal database. 43 systems have official PFAS monitoring records from the EPA UCMR 5 program (2023–2025). About 18% of HI residents use private wells, which fall outside federal utility compliance monitoring.
No open health-based violations are currently recorded in the EPA SDWIS database for Hawaii's tracked water systems. Always verify with your utility's Consumer Confidence Report for annual test results.
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.
Safest Large Utilities
Hawaii systems with no open health violations serving 10,000+ residents.
Utilities in Hawaii
1–25 of 75Hnl-windward-pearl Harbor
HI0000331 · 631,389 served
Waipahu-ewa-waianae
HI0000335 · 217,479 served
Wailuku
HI0000212 · 74,511 served
Joint Base Pearl Harbor-hickam
HI0000360 · 65,230 served
Mililani
HI0000367 · 50,573 served
Hilo
HI0000101 · 39,477 served
Schofield Barracks
HI0000345 · 37,920 served
Lihue-kapaa
HI0000400 · 34,854 served
Makawao
HI0000213 · 29,868 served
North Kona
HI0000131 · 29,581 served
Wahiawa
HI0000333 · 23,348 served
Lahaina
HI0000214 · 20,065 served
Marine Corps Base Hawaii
HI0000356 · 16,300 served
Kalaheo-koloa
HI0000434 · 12,660 served
Waikoloa
HI0000135 · 12,100 served
Waipio Heights
HI0000334 · 11,516 served
Waialua-haleiwa
HI0000332 · 9,996 served
South Kohala
HI0000130 · 9,612 served
Kaanapali
HI0000205 · 8,000 served
Upper Kula
HI0000215 · 7,686 served
Fort Shafter
HI0000341 · 7,067 served
Princeville
HI0000428 · 6,911 served
South Kona
HI0000132 · 6,512 served
Nctams Eastpac
HI0000357 · 6,470 served
Olaa-mountain View
HI0000112 · 6,467 served
Key Contaminant Concerns in Hawaii
These contaminants appear most frequently in Hawaii utility records or pose elevated risk in this region based on EPA data.
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. Critically, a utility's water quality report can show zero detected lead at the treatment plant while your specific tap still delivers elevated lead — because the contamination happens inside the distribution system and your home's plumbing, not at the source.
EPA limit: 15 ppb (action level)
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.
EPA limit: 80 µg/L (TTHMs) / 60 µg/L (HAA5)
City Water Reports in Hawaii
Tap water quality pages for Hawaii cities — violations, PFAS records, utility profiles, and official source links.
Independent Water Testing
Find a certified lab in Hawaii
Utility compliance records show what water systems report to the EPA. An independent test from a certified laboratory confirms what's actually in your tap water. Hawaii labs can test for PFAS, lead, nitrates, bacteria, and dozens of other contaminants.
Explore Water Quality in Hawaii
Hnl-windward-pearl Harbor
Violation history, PFAS records, and official source links
Waipahu-ewa-waianae
Violation history, PFAS records, and official source links
Wailuku
Violation history, PFAS records, and official source links
PFAS monitoring records — Hawaii
43 water systems in Hawaii with EPA UCMR 5 records
Lead in Hawaii drinking water
State-specific lead data, violation utilities, and testing guidance
PFAS in Hawaii drinking water
State-specific PFAS data, MCL context, and treatment options
Certified water testing labs in Hawaii
Labs certified for PFAS (EPA 533/537.1), lead, and bacteria testing
Water treatment options
Reverse osmosis, activated carbon, and filtration guides with cost ranges
Data sources and methodology
How WaterUtilityReport.com sources and validates official EPA data
Common Questions About Hawaii Drinking Water
Does Hawaii drinking water have PFAS?
43 Hawaii water systems have EPA UCMR 5 PFAS monitoring records (2023–2025)
Which Hawaii water utilities have open violations?
Browse Hawaii utility compliance records and violation history
How do I test my water in Hawaii?
State-certified labs for PFAS (EPA 533/537.1), lead, nitrate, and bacteria testing
What treatment removes PFAS from HI tap water?
Reverse osmosis removes PFAS, lead, arsenic, and nitrates — cost, maintenance, and NSF certification explained
What do Hawaii PFAS records tell me about my water?
EPA limits, health context, and what UCMR 5 detection above MRL means for your water
How is Hawaii water quality data sourced here?
EPA SDWIS violations, UCMR 5 PFAS records, and CCR data — sources, accuracy notes, and limitations
Hawaii Water FAQs
Data sources: Utility compliance and violation data from EPA SDWIS (Safe Drinking Water Information System). PFAS monitoring records from EPA UCMR 5 (Unregulated Contaminant Monitoring Rule 5, 2023–2025). Contaminant data from EPA and ATSDR public references. This page summarizes public records — it is not a compliance determination. Methodology →
Last updated: 2026-04-22