Tap Water Results

Is Honolulu, HI tap water safe?

Data: U.S. EPA · How we read the data · How we check it

Summary

No federal limits exceeded in EPA data for Honolulu Board of Water Supply – Windward-Pearl Harbor. 1 PFAS were detected below the limits.

3 public water systems serve parts of Honolulu. The largest, Honolulu Board of Water Supply – Windward-Pearl Harbor, serves 631,389 people. Your water bill names your system.

Largest system

Honolulu Board of Water Supply – Windward-Pearl Harbor

631,389 people · Groundwater · EPA ID HI0000331

PFASHighest averageLimitStatus
PFOA
Not detected
–4 pptNot detected
PFOS
Not detected
–4 pptNot detected
PFHxS
Detected, below limit
1.5 ppt10 pptDetected, below limit
PFNA
Not detected
–10 pptNot detected
HFPO-DA (GenX)
Not detected
–10 pptNot detected

ppt = parts per trillion. "Highest average" is the highest average at any of the system's entry points, the way EPA compares results with the limits.

Lead: 0 ppb at the 90th percentile (Dec 2018, and 9 in 10 homes sampled were at or below it) No results since 2018
Health-based violations since 2016: 0

Full Honolulu Board of Water Supply – Windward-Pearl Harbor results

Across Hawaii, 0 of 44 water systems EPA tested had PFAS above a 2024 federal limit, and 0 systems were above the lead action level in results from the last five years. Hawaii results.

Honolulu homes and lead pipes

65%
of homes built before 1980 (Hawaii 51%, US 50%)
10%
built before 1950 (Hawaii 6%)
51%
of households rent (Hawaii 37%)

Lead service lines and lead solder were allowed until 1986, so homes from before then are the ones to check. Honolulu Board of Water Supply – Windward-Pearl Harbor publishes a service line inventory you can search by address. Look up your address. Renting? Ask your landlord what the service line is made of, because it's their pipe to replace. How to check your own line.

Housing: Census American Community Survey 2020–2024 5-year estimates for Urban Honolulu CDP (tables B25034, B25003). Estimates for small places have a margin of error.

Other water systems serving Honolulu

  • Kamehameha Schools Water System
    4,000 people · Groundwater · Hawaii · reported ZIPs here
    No PFAS above limits
  • The Queen's Medical Center Water System
    3,440 people · Groundwater · Hawaii · reported ZIPs here
    No PFAS above limits
Honolulu ZIP codes (11)
  • 96813
  • 96814
  • 96815
  • 96816
  • 96817
  • 96818
  • 96819
  • 96822
  • 96826
  • 96848
  • 96850

Questions

Is Honolulu tap water safe to drink?

Honolulu Board of Water Supply – Windward-Pearl Harbor has had no health-based violations since 2016. Utility data can't show lead from your own pipes: if your home was built before 1986, test your tap. Your utility's annual Consumer Confidence Report is the official summary.

Who supplies water in Honolulu, HI?

3 public water systems serve parts of Honolulu. The largest is Honolulu Board of Water Supply – Windward-Pearl Harbor (631,389 people). Your water bill names your system. The EPA ID is also on your utility's Consumer Confidence Report.

Does Honolulu tap water have PFAS?

Honolulu Board of Water Supply – Windward-Pearl Harbor had 1 PFAS detected at least once in EPA's 2023–2025 testing, all with averages below the federal limits.

Do Honolulu homes have lead pipes?

Census estimates put 65% of Honolulu homes as built before 1980 (Hawaii: 51%). Lead service lines and lead solder were allowed until 1986, so older homes are more likely to have them. Honolulu Board of Water Supply – Windward-Pearl Harbor's service line inventory says what your line is made of. The only way to know for your home is to check the line where it enters the house and test your tap.

Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.