TapWaterMap

HI / Honolulu

HI · Tap water records

Honolulu tap water, in plain English

Here is what the EPA's own data shows about tap water in Honolulu. According to EPA SDWIS data retrieved June 2026, Honolulu is served by 16 active community water systems, together reported to serve about 961,860 people.

As of June 2026, EPA records show 13 violations across the community water system(s) serving Honolulu, going back to the earliest EPA record. 1 of these are classified by the EPA as health-based (a contaminant recorded above the limit the EPA tracks); the rest are monitoring or reporting violations. Each is listed by system below, with its status.

What the EPA has on record, by system

Hnl-Windward-Pearl Harbor

631,389 served · groundwater · PWSID HI0000331

As of June 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.

Waipahu-Ewa-Waianae

217,479 served · groundwater · PWSID HI0000335

As of June 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.

Mililani

50,573 served · groundwater · PWSID HI0000367

As of June 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.

Wahiawa

23,348 served · groundwater · PWSID HI0000333

As of June 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.

Waipio Heights

11,516 served · groundwater · PWSID HI0000334

As of June 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.

Waialua-Haleiwa

9,996 served · groundwater · PWSID HI0000332

As of June 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.

Waialee-Sunset Beach

4,916 served · groundwater · PWSID HI0000366

As of June 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.

Kamehameha Schools

4,000 served · groundwater · PWSID HI0000319

As of June 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.

The Queen'S Medical Center

3,440 served · groundwater · PWSID HI0000312

Kahuku

2,730 served · groundwater · PWSID HI0000365

Dillingham Airfield

1,800 served · groundwater · PWSID HI0000338

As of June 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.

Waiahole

300 served · groundwater · PWSID HI0000368

Punalu'U

200 served · groundwater · PWSID HI0000114

Shasta Cascade Mobilehome Park

100 served · groundwater · PWSID CA4700627

As of June 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.

Woodlands At Nuuanu

48 served · groundwater · PWSID HI0000372

As of June 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.

Poamoho

25 served · groundwater · PWSID HI0000371

What this means

A health-based violation means a contaminant was recorded above the limit the EPA tracks for it. A monitoring or reporting violation means a required test or report was late or missed — not that a contaminant was measured above a limit. “Returned to compliance” means the EPA recorded the issue as resolved.

This page summarizes the EPA's own records and does not assess whether your water is safe to drink. For the most current details, you can verify every record directly with the EPA, and contact your water system with questions.

Source: U.S. EPA Envirofacts SDWIS, retrieved June 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.