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Not health advice. Contact your local water utility for concerns.
Data from EPA Water Quality Reports. For official information, contact your water utility or health department.
EPA records for HNL-WINDWARD-PEARL HARBOR • Updated September 2026
Grade A — based on EPA compliance records, lead testing and PFAS monitoring
HNL-WINDWARD-PEARL HARBOR has a clean recent record: no health-based violations in the last five years and no lead, PFAS or historical monitoring result that costs it more than a few points.
Yes — by EPA's records Honolulu, HI tap water is safe to drink and earns an A. The grade rests on low-level PFAS (PFHxS) detected below federal limits. Lead from your own service line or plumbing is the main risk city-level data cannot see, so homes built before 1986 should still test at the tap.
Yes — by EPA's records Honolulu, HI tap water is safe to drink and earns an A. The grade rests on low-level PFAS (PFHxS) detected below federal limits. Lead from your own service line or plumbing is the main risk city-level data cannot see, so homes built before 1986 should still test at the tap.
HNL-WINDWARD-PEARL HARBOR's most recent Lead and Copper Rule result (2016-01-01 to 2018-12-31) was 0 ppb at the 90th percentile, below EPA's 15 ppb action level. Because lead usually comes from service lines and household plumbing, homes built before 1986 should still test at the tap.
Yes. EPA's UCMR5 sampling (2023-05-02 to 2025-12-11) detected PFHxS, all below federal MCLs. Reverse osmosis and certified activated-carbon filters reduce PFAS.
No. EPA's SDWIS shows no violations of any kind for HNL-WINDWARD-PEARL HARBOR since 2016.
HNL-WINDWARD-PEARL HARBOR reports groundwater as its primary source and serves about 631,389 people (EPA PWSID HI0000331).
Optional but sensible. The findings on this page are below federal limits; an NSF-certified pitcher or under-sink filter handles PFAS and improves taste.
Want to know what's really in your Honolulu tap water?
PFHxS were detected in Honolulu's water at low levels in 2023–2025 EPA monitoring.
Tap Score certified lab · Amazon. We may earn a commission, at no extra cost to you.
HNL-WINDWARD-PEARL HARBOR · SDWIS records since 2016 · 5-year window starts 2021-09-13
EPA records no health-based violations for this system in the last five years.
No violations of any kind on file since 2016.
Source: ECHO SDWA bulk download (SDWA_VIOLATIONS_ENFORCEMENT.csv, SDWIS 2026Q2, file dated 2026-07-09, fetched 2026-09-13)
EPA Lead and Copper Rule 90th-percentile results reported by HNL-WINDWARD-PEARL HARBOR
Well below the 15 ppb action level. In the most recent monitoring period on file (2016-01-01 to 2018-12-31), 90% of the homes HNL-WINDWARD-PEARL HARBOR sampled had lead at or below 0 ppb. This result is from before 2020, so it is shown for context but not scored.
EPA's action level is 15 ppb (dropping to 10 ppb under the 2024 Lead and Copper Rule Improvements). There is no safe level of lead; the 90th-percentile figure describes the system, not your tap — homes with lead service lines or pre-1986 plumbing can be higher.
| Monitoring period | Lead 90th percentile | vs 15 ppb action level |
|---|---|---|
| 2016-01-01 → 2018-12-31 | 0 ppb | Well below the 15 ppb action level |
| 2015-01-01 → 2015-12-31 | 0 ppb | Well below the 15 ppb action level |
| 2014-01-01 → 2014-12-31 | 0 ppb | Well below the 15 ppb action level |
| 2013-01-01 → 2013-06-30 | 0.92 ppb | Well below the 15 ppb action level |
| 2012-07-01 → 2012-12-31 | 0.98 ppb | Well below the 15 ppb action level |
| 2007-01-01 → 2009-12-31 | 1.6 ppb | Well below the 15 ppb action level |
| 2004-01-01 → 2006-12-31 | 1.2 ppb | Well below the 15 ppb action level |
| 2001-01-01 → 2003-12-31 | 0 ppb | Well below the 15 ppb action level |
| 1998-01-01 → 2000-12-31 | 0 ppb | Well below the 15 ppb action level |
| 1992-07-01 → 1992-12-31 | 0.1 ppb | Well below the 15 ppb action level |
| 1992-07-01 → 1992-12-31 | 2.5 ppb | Well below the 15 ppb action level |
| 1992-01-01 → 1992-06-30 | 0.25 ppb | Well below the 15 ppb action level |
Source: ECHO SDWA bulk download (SDWA_LCR_SAMPLES.csv, SDWIS 2026Q2, file dated 2026-07-09, fetched 2026-09-13)
EPA UCMR5 monitoring, 2023-05-02 to 2025-12-11 · 2,668 PFAS results at entry points to the distribution system
PFHxS detected at low levels; no compound was at or above its federal MCL. Detections below the MCL are common in surface-water systems and are reported here exactly as EPA published them.
| Compound | Detects / samples | Max (ppt) | Reporting limit | EPA MCL |
|---|---|---|---|---|
| PFOA | 0 / 92 | < 4 | 4 ppt | 4 ppt |
| PFOS | 0 / 92 | < 4 | 4 ppt | 4 ppt |
| PFHxS | 1 / 92 | 3 | 3 ppt | 10 ppt |
| PFNA | 0 / 92 | < 4 | 4 ppt | 10 ppt |
| HFPO-DA | 0 / 92 | < 5 | 5 ppt | 10 ppt |
| PFBS | 0 / 92 | < 3 | 3 ppt | hazard index only |
“< 4 ppt” means below the laboratory reporting limit, not zero. ppt = parts per trillion (ng/L). Results are for finished water leaving the treatment plant.
What PFAS are and how to remove them → · Best filters for PFAS →
Source: UCMR5 occurrence data, EPA Data Summary July 2026 (UCMR5_All.txt)
EPA Six-Year Review 4 compliance samples for HNL-WINDWARD-PEARL HARBOR · finished water only · dated data, released 2024
These are the regulated-contaminant samples HNL-WINDWARD-PEARL HARBOR reported to its state between 2012 and 2019 — the most recent nationwide sample-level dataset EPA has published. Every scored contaminant stayed within its Maximum Contaminant Level (MCL) and averaged below 80% of the limit. Treat this as history, not today's tap water.
| Contaminant | Samples | Average | Max | EPA limit | Status |
|---|---|---|---|---|---|
| Arsenic | 1202 detects | 0.023 µg/L | 1.8 µg/L | 10 µg/LMCL | Within MCL |
| Nitrate (as N) | 404383 detects | 0.434 mg/L | 2.4 mg/L | 10 mg/LMCL | Within MCL |
| Fluoride | 39773 detects | 0.011 mg/L | 0.084 mg/L | 4 mg/LMCL | Within MCL |
| Chromium (total) | 120116 detects | 1.774 µg/L | 6.1 µg/L | 100 µg/LMCL | Within MCL |
| Uranium (combined) | 751 detects | 0.028 µg/L | 2.086 µg/L | 30 µg/LMCL | Within MCL |
| Radium-226/228 | 750 detects | 0 pCi/L | ND | 5 pCi/LMCL | Not detected |
| Gross alpha | 754 detects | 0.08 pCi/L | 5.4 pCi/L | 15 pCi/LMCL | Within MCL |
| Total trihalomethanes (TTHM) | 293158 detects | 1.778 µg/L | 17 µg/L | 80 µg/LMCL (LRAA) | Within MCL |
| Haloacetic acids (HAA5) | 1670 detects | 0 µg/L | ND | 60 µg/LMCL (LRAA) | Within MCL |
| Lead (tap samples) | 1217 detects | 0.061 µg/L | 2.5 µg/L | 15 µg/Laction level (90th percentile) | Reported, not scored (compliance is on the 90th percentile) |
| Copper (tap samples) | 12067 detects | 5.083 µg/L | 180 µg/L | 1300 µg/Laction level (90th percentile) | Reported, not scored (compliance is on the 90th percentile) |
Averages count non-detects as zero. TTHM and HAA5 limits are locational running annual averages, so a single high sample is not a violation — we grade those on the average only. Lead and copper rows are individual tap samples and are shown for context; compliance (and our score) uses the 90th-percentile result above. LRAA = locational running annual average; ND = not detected.
Source: SYR4 Six-Year Review compliance monitoring data 2012–2019 (released 2024-03)
A point-of-use (under-sink) system typically runs $200-$600 installed; whole-house treatment $1,000-$3,000+ depending on flow and what has to come out. Tell us where you are and a certified water-treatment installer serving Honolulu will follow up - no obligation.
HNL-WINDWARD-PEARL HARBOR · 109,006 service lines inventoried · Q2 2026 snapshot
HNL-WINDWARD-PEARL HARBOR reports no lead or galvanized-requiring-replacement service lines and has classified 100% of its 109,006 lines as non-lead. Lead can still come from pre-1986 plumbing and fixtures inside a home.
Source: EPA SDWIS Service Line Inventory (Q2 2026) · PWS ID HI0000331 · See all Hawaii lead service lines. We may earn a commission from filters and test kits, at no extra cost to you.
Groundwater systems draw from wells; naturally occurring arsenic, nitrate, radium and uranium are the readings to watch, along with PFAS near industrial or military sites.
How to test your tap water and the treatment options that actually fit Honolulu homes
The most reliable way to know what is actually coming out of your tap is a certified mail-in lab test. City-wide EPA data (like the report above) reflects the water leaving the treatment plant, but contaminants such as lead and copper can be picked up from your own service line and household plumbing — so the water at your Honolulu faucet can differ from the system average. A state-certified lab measures dozens of contaminants at once with results you can trust; you can also find one near you through the EPA's certified-lab list at epa.gov/dwlabcert. Hardware-store test strips are cheaper and instant, but they only screen for a few basics (chlorine, hardness, pH, and a rough lead pass/fail) and are far less accurate — treat them as a first look, not a diagnosis.
Match the treatment to what your test finds. Reverse osmosis (RO) removes the widest range of contaminants — lead, arsenic, nitrate, PFAS, and dissolved solids — which makes an under-sink reverse osmosis system the most thorough choice for Honolulu households with heavy-metal or PFAS concerns. If your main issue is taste, odor, or chlorine, an activated carbon filter (pitcher, faucet, or under-sink) is simpler and cheaper and handles chlorine and many organic compounds well, though carbon alone does not remove arsenic, nitrate, or most PFAS. NSF-certified pitchers rated for lead reduction are the easiest way to start today while you decide on a permanent setup.
We may earn a commission from testing kits and filters purchased through these links, at no extra cost to you.
What Honolulu residents measured at their own tap (ZIPs 96813, 96814, 96815, 96816 +10 more). All reader results →
Reader submissions are unverified and shown separately from EPA data. They reflect one tap on one day, not the utility's compliance record.
No reader results for Honolulu yet - yours would be the first. A hardness or TDS number from a $10 strip kit is enough to start the map.
Help build the first reader-sourced water map. Enter whatever your test strip, TDS pen or lab report shows - one number is enough.
Honolulu ranks #3 of 4 graded Hawaii cities.
Deep-dive guides for the specific contaminants EPA data flagged in Honolulu's water, with removal options for each.
Yes — by EPA's records Honolulu, HI tap water is safe to drink and earns an A. The grade rests on low-level PFAS (PFHxS) detected below federal limits. Lead from your own service line or plumbing is the main risk city-level data cannot see, so homes built before 1986 should still test at the tap.
HNL-WINDWARD-PEARL HARBOR's most recent Lead and Copper Rule result (2016-01-01 to 2018-12-31) was 0 ppb at the 90th percentile, below EPA's 15 ppb action level. Because lead usually comes from service lines and household plumbing, homes built before 1986 should still test at the tap.
Yes. EPA's UCMR5 sampling (2023-05-02 to 2025-12-11) detected PFHxS, all below federal MCLs. Reverse osmosis and certified activated-carbon filters reduce PFAS.
No. EPA's SDWIS shows no violations of any kind for HNL-WINDWARD-PEARL HARBOR since 2016.
HNL-WINDWARD-PEARL HARBOR reports groundwater as its primary source and serves about 631,389 people (EPA PWSID HI0000331).
Optional but sensible. The findings on this page are below federal limits; an NSF-certified pitcher or under-sink filter handles PFAS and improves taste.
PFHxS were detected in Honolulu's water at low levels in 2023–2025 EPA monitoring.
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Based on contaminants detected in your water, these resources may be helpful:
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Tap water is one piece of the picture — our sister sites cover the rest for Honolulu, HI.
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