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Not health advice. Contact your local water utility for concerns.
Data from EPA Water Quality Reports. For official information, contact your water utility or health department.
Water quality scores for 15 cities in Hawaii
Mostly yes. None of the 4 Hawaii water systems we grade from EPA records has a health-based violation in the last five years, and the state averages 99/100 (11 above the national 88). Lead from a home's own plumbing is the risk city data cannot see.
Hawaii's official certified-lab list, when to test well vs city water, typical lab prices, and how to take a first-draw lead sample.
Across the 4 Hawaii water systems we can grade from EPA records, the average score is 99/100 — 11 points above the U.S. national average of 88/100. 100% of graded Hawaii cities (4 of 4) score above that national benchmark, and 4 earn a Grade A. None has a health-based EPA violation in the last five years. 11 cities are not graded because we have not yet matched them to an EPA water system.
The contaminants most commonly flagged in Hawaii water systems are disinfection byproducts (chlorination), lead (older infrastructure) and nitrates (agricultural areas). See the full breakdown in our Hawaii water quality rankings or compare against the cities with the best water quality in America.
See the top 20 cities with the cleanest, safest drinking water
Complete water quality rankings for every city in Hawaii
39,477 residents
23,348 residents
631,389 residents
217,479 residents
50,922 residents
No EPA water-system match yet — no score.
47,698 residents
No EPA water-system match yet — no score.
38,635 residents
No EPA water-system match yet — no score.
34,597 residents
No EPA water-system match yet — no score.
27,629 residents
No EPA water-system match yet — no score.
26,337 residents
No EPA water-system match yet — no score.
24,866 residents
No EPA water-system match yet — no score.
21,423 residents
No EPA water-system match yet — no score.
21,039 residents
No EPA water-system match yet — no score.
18,248 residents
No EPA water-system match yet — no score.
15,132 residents
No EPA water-system match yet — no score.
This state's water quality reflects local geographic conditions, industrial activities, and water infrastructure. Water quality can vary significantly between communities, with some areas enjoying excellent tap water while others face contamination challenges requiring treatment.
Across the 4 Hawaii cities graded from EPA records, the average water quality score is 99/100. The highest-rated city is Hilo with a score of 100/100, while Waipahu has the most room for improvement at 98/100.
Hawaii cities average 99/100, but contaminants still vary at the tap and lead can leach from your own household plumbing after the water arrives. A certified filter removes trace contaminants and improves taste — here are two proven picks.
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Water sources typically include a combination of surface water (rivers, lakes, reservoirs) and groundwater. The specific sources serving your community depend on local geography and infrastructure. Check your local water utility's Consumer Confidence Report for details about your water source.
These contaminants have been detected in various Hawaii water systems
State environmental and health agencies oversee drinking water quality in compliance with federal EPA standards. Public water systems are required to test regularly and report results to residents through annual Consumer Confidence Reports.
Water quality concerns vary by location. Common issues include lead from older plumbing, agricultural runoff in rural areas, and industrial contamination near manufacturing sites. Check your local water quality report and consider testing if you have specific concerns.
Review your annual Consumer Confidence Report to understand local water quality. Consider having your water tested if you use a private well or have concerns about your plumbing. Water filters certified to remove specific contaminants can address most common water quality issues.
Most Hawaii cities we grade have tap water in good standing with EPA. With an average score of 99/100 across 4 graded cities, Hawaii generally has good water quality. However, water quality varies by utility, so check your specific city's report.
The most common water quality concerns in Hawaii include disinfection byproducts (chlorination), lead (older infrastructure), nitrates (agricultural areas). These contaminants can come from natural sources, industrial activities, or aging infrastructure. Review your city's specific report to see which contaminants affect your area.
Whether you need a water filter depends on your specific location and health concerns. Most Hawaii cities have water that meets EPA standards, though some residents prefer additional filtration for taste or extra protection. Look for filters certified by NSF/ANSI to remove the specific contaminants found in your area.
Public water systems in Hawaii are required to provide annual Consumer Confidence Reports (CCRs) to residents. You can usually find your report on your water utility's website, request it by phone, or access it through the EPA's database. Our city-level reports above summarize key information from these official sources.
Lead can be present in Hawaii water, primarily from older plumbing infrastructure. Homes built before 1986 may have lead pipes or lead solder. While water treatment plants remove lead, it can leach into water from service lines and home plumbing. Check your city's specific report for lead testing data, and consider having your tap water tested if you live in an older home.
PFAS ("forever chemicals") have been detected in water systems across the United States, including in Hawaii. These chemicals are associated with industrial sites, military bases, and firefighting foam use. The EPA has set new PFAS limits effective 2024. Check individual Hawaii city reports for PFAS testing results in your area.
On EPA records, Hilo has the highest water quality score in Hawaii at 100/100 (Grade A). However, "best" depends on your specific health concerns. View our Best Water Quality in Hawaii page for a complete ranking.
Public water systems in Hawaii are required by the EPA to test water regularly. Testing frequency depends on the contaminant: bacteria testing occurs daily to weekly, while chemical contaminants may be tested quarterly or annually. Results are published in annual Consumer Confidence Reports. Our site aggregates this data from EPA's SDWIS database.
Compare water quality across counties and find data for your area