States › Hawaii › Honolulu County

Honolulu County, HI Water Quality

Water quality data for 11 public water systems serving Honolulu County, Hawaii — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 11 water systems · 49 cities
✅
Excellent — All Systems Performing Well

Water quality across the county is outstanding with minimal violations and very low lead levels.

A

Honolulu County Earns a A

Honolulu County: 49 communities across 11 water systems. 100.0% have no open violations.

  • Median lead where detected: none detected
  • 0 communities with a lead detection, 49 reporting none detected
  • 0 communities with PFAS above the federal limit
  • 7 with significant inspection deficiencies
  • 100.0% of communities have no open violations
—
Median Lead Level
County-wide, 90th percentile
11
Water Systems
Active CWS & NTNCWS
100%
Violation-Free
No active violations on record
How we grade counties: MyWaterIQ uses EPA SDWIS enforcement data — actual MCL violations and lead test results — not the aspirational MCLG targets used by some sites. A grade reflects real compliance history, not theoretical risk. Learn more →

Cities by Water Quality

⭐ Best Performing
  • Kawela Bay
    Not detected
    No federal limits exceeded on record
    A
  • Urban Honolulu
    Not detected
    No federal limits exceeded on record
    A
  • East Honolulu
    Not detected
    No federal limits exceeded on record
    A
  • Pearl City
    Not detected
    No federal limits exceeded on record
    A
  • Waipahu
    Not detected
    No federal limits exceeded on record
    A
⚠ Needs Attention
  • Mililani Mauka
    Not detected
    5 significant inspection deficiencies
    B
  • Schofield Barracks
    Not detected
    1 significant inspection deficiency
    A
  • Haleiwa
    Not detected
    2 significant inspection deficiencies
    A
  • Waialua
    Not detected
    2 significant inspection deficiencies
    A
  • Mililani Town
    Not detected
    1 significant inspection deficiency
    A

All Cities in Honolulu County

Urban Honolulu Not detected A
East Honolulu Not detected A
Pearl City Not detected A
Waipahu Not detected A
Kailua Not detected A
Kaneohe Not detected A
Ewa Gentry Not detected A
Kapolei Not detected A
Makakilo Not detected A
Wahiawa Not detected A
Mililani Mauka Not detected B
Ewa Beach Not detected A
Halawa Not detected A
Ocean Pointe Not detected A
Royal Kunia Not detected A
Schofield Barracks Not detected A
Waimalu Not detected A
Waianae Not detected A
Nanakuli Not detected A
Maili Not detected A
Makaha Not detected A
Ahuimanu Not detected A
Kaneohe Base Not detected A
Aiea Not detected A
Ewa Villages Not detected A
Waikele Not detected A
Hickam Housing Not detected A
Waipio Not detected A
Laie Not detected B
Waimanalo Not detected A
West Loch Estate Not detected A
East Kapolei Not detected A
Kahaluu Not detected A
Whitmore Village Not detected A
Pupukea Not detected A
Waimanalo Beach Not detected A
Heeia Not detected A
Haleiwa Not detected A
Waialua Not detected A
Mililani Town Not detected A
Kahuku Not detected B
Wheeler AFB Not detected A
Ko Olina Not detected A
Maunawili Not detected A
Mokuleia Not detected A
Kalaeloa Not detected A
Makaha Valley Not detected A
Hauula Not detected B
Kawela Bay Not detected A
Showing 49 cities
No active violations Active violations

About Honolulu County Drinking Water

Honolulu County is served by 11 water systems covering 49 communities. No community here has an open violation on record.

Lead was not detected in any community in Honolulu County that reported a result.

No community here has PFAS above the federal limit on record. State inspectors recorded significant deficiencies at 7 of them.

Frequently Asked Questions

Is Honolulu County tap water safe to drink?▼
No community in Honolulu County has an open violation on record. No community has PFAS above the federal limit on record.
What is the lead level in Honolulu County?▼
No community reported a lead detection.
How many water systems serve Honolulu County?▼
11 community water systems serve 49 communities here.
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