Hawaii Water Quality Rankings 2026

All 15 cities ranked by water quality score

State Average81/100

Cities Ranked

Waimalu

Best City (92/100)

Kaneohe

Lowest Score (67/100)

73%

Above National Avg

Grade Distribution

How Hawaii's 15 cities are distributed by water quality grade

A Range

40% of cities

B Range

53% of cities

C Range

7% of cities

0% of cities

Cities with good water quality (B or better)73%

11 out of 15 cities meet or exceed a B grade for water quality

All 15 Hawaii Cities Ranked

Sorted by water quality score from best to worst. Click any city for a detailed water quality report.

Rank	City	Score	Grade	Population	Top Concern
1	Waimalu	92/100	A	15,132	None identified
2	Hilo	89/100	A-	45,703	None identified
3	East Honolulu	87/100	A-	50,922	None identified
#4	Mililani Town	87/100	A-	27,629	None identified
#5	Wahiawa	86/100	A-	17,821	None identified
#6	Ewa Gentry	85/100	A-	24,866	None identified
#7	Kahului	84/100	B+	26,337	None identified
#8	Mililani Mauka	83/100	B+	21,039	None identified
#9	Waipahu	83/100	B+	43,485	None identified
#10	Kailua	82/100	B+	38,635	None identified
#11	Kihei	81/100	B+	21,423	None identified
#12	Pearl City	72/100	B-	47,698	None identified
#13	Honolulu	70/100	B-	345,064	None identified
#14	Makakilo	70/100	B-	18,248	None identified
#15	Kaneohe	67/100	C+	34,597	None identified

Key Findings

The best water quality in Hawaii is found in Waimalu with a score of 92/100 and a grade of A. This puts Waimalu among the top-performing cities in the country for drinking water safety.

The most concerning water quality is in Kaneohe scoring 67/100 with a grade of C+. Residents may want to consider home water testing and filtration options.

The statewide average score is 81/100, which is 9 points above the national average of 72/100. Over half (73%) of Hawaii cities score above the national average, though some areas face challenges.

Frequently Asked Questions

Which city in Hawaii has the best water quality?

Waimalu has the best water quality in Hawaii with a score of 92/100 and a grade of A. This score is based on contaminant levels, EPA compliance history, and infrastructure quality. Waimalu ranks among the top cities nationally for water quality.

Is Hawaii tap water safe to drink?

Water quality varies across Hawaii. The state average score is 81/100. 73% of Hawaii cities have good water quality (grade B or better). All cities in Hawaii maintain at least a C-grade, though individual results can vary by neighborhood and home plumbing. Always check your specific city's water quality report for the most accurate local information.

How many Hawaii cities have water quality concerns?

Of the 15 cities tracked in Hawaii, 0 cities have a D or F grade, indicating significant water quality concerns. An additional 1 city falls in the C range, suggesting moderate issues. 11 out of 15 cities (73%) score above the national average of 72/100. Residents concerned about their water quality can check their city's detailed report for specific contaminant information.