Honolulu County Water Quality
Hawaii
According to EPA SDWIS, Honolulu County, Hawaii hosts 20 community water systems covering about 163,302 people. The same extract lists 6 health-based violation records across 2 systems. Counts are historical EPA registry rows, not a current compliance or drinkability score.
Honolulu County, Hawaii hosts 20 EPA-regulated community water systems delivering drinking water to approximately 163,302 people. Each system is catalogued in the EPA Safe Drinking Water Information System (SDWIS) under the Safe Drinking Water Act, which mandates monitoring for dozens of regulated contaminants, public notification when standards are exceeded, and the issuance of an annual Consumer Confidence Report.
PlainEnviro's health-based SDWIS extract shows 6 violation records across these active community systems, with 2 systems carrying at least one record. The extract excludes monitoring and reporting violations. The county contains 16 incorporated places where these systems deliver service. 4 Superfund sites are also listed within the county.
A historical health-based registry row does not establish water delivered today or describe current compliance. For current conditions, request the utility's most recent Consumer Confidence Report or contact the Hawaii drinking water program. Figures shown here reflect only the health-based subset fetched from federal EPA SDWIS.
What water systems serve Honolulu County?
| System Name | Pop. Served | Violations | Status |
|---|---|---|---|
| JOINT BASE PEARL HARBOR-HICKAM | 65,230 | 0 | Clean |
| SCHOFIELD BARRACKS | 37,920 | 0 | Clean |
| MARINE CORPS BASE HAWAII | 16,300 | 0 | Clean |
| FORT SHAFTER | 7,067 | 0 | Clean |
| NCTAMS EASTPAC | 6,470 | 0 | Clean |
| ALIAMANU | 6,406 | 0 | Clean |
| LAIE WATER COMPANY | 5,577 | 0 | Clean |
| TRIPLER ARMY MEDICAL CNTR | 5,555 | 0 | Clean |
| KAMEHAMEHA SCHOOLS | 4,000 | 0 | Clean |
| THE QUEEN'S MEDICAL CENTER | 3,440 | 0 | Clean |
| DILLINGHAM AIRFIELD | 1,800 | 0 | Clean |
| PACIFIC MISSILE RANGE FACILITY | 1,200 | 0 | Clean |
| KUNIA VILLAGE | 650 | 0 | Clean |
| CAMP STOVER | 595 | 0 | Clean |
| WAIAWA CORRECTIONAL FACILITY | 444 | 5 | Health |
| WAIAHOLE | 300 | 1 | Health |
| PUNALU'U | 200 | 0 | Clean |
| KAHUKU AIR BASE | 75 | 0 | Clean |
| WOODLANDS AT NUUANU | 48 | 0 | Clean |
| POAMOHO | 25 | 0 | Clean |
Cities in Honolulu County
How does Honolulu County compare in Hawaii?
Of the 5 Hawaii counties with at least one community water system on file, Honolulu County ranks #3 by number of systems (20).
Either side of it: Hawaii County (36), Maui County (31), Kauai County (16), Kalawao County (1)
What are Honolulu County's health-based records for?
Honolulu County's health-based violation records carry 2 distinct EPA codes: some name a substance, others the drinking-water rule that was breached. Counts are records on file in the EPA SDWIS extract, not current test results, and a historical record does not establish present water quality.
| Contaminant | Records | Systems |
|---|---|---|
| Surface Water Treatment Rule | 5 | 1 |
| Revised Total Coliform Rule | 1 | 1 |
Superfund Sites in Honolulu County
| Site Name | NPL Status | Site Score |
|---|---|---|
| Del Monte Corp. (Oahu Plantation) | NPL Site | 50.00 |
| Naval Computer and Telecommunications Area Master Station Eastern Pacific | NPL Site | 50.00 |
| Pearl Harbor Naval Complex | NPL Site | 70.82 |
| Schofield Barracks (USARMY) | Deleted NPL Site | 28.90 |
About This Data
Water system data comes from the EPA's Safe Drinking Water Information System (SDWIS). PlainEnviro's violation fetch is restricted upstream to records EPA flags as health-based and then joined to active community water systems. Monitoring and reporting violations are not included.
Figures here are the current EPA SDWIS extract joined to the 20 community water systems whose service area falls in Honolulu County, ranked against the 5 Hawaii counties with at least one system on file. Data current as of 2026-08-10. Editorial standards, methodology, report an error.
A health-based violation row in this extract is a historical EPA registry entry. It does not describe water delivered today or current compliance status. Many records are later resolved, and public water systems notify customers when required. For current conditions, contact your local water utility or the state drinking water program.
Read our methodology - how this data is sourced, computed, and verified.