01The verdict: is Pearl Harbor water safe?
Pearl Harbor's tap water meets most EPA standards but has areas that warrant attention. With a grade of A (94.8/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 65,230 residents using groundwater (wells).
Vanadium is over its legal limit
Measured at 32.00 µg/L against the EPA Short-term HA of 21 µg/L. The ledger below shows how far over — and which filter removes it.
See the measurement ↓Lead is well under the limit
90th-percentile lead is 0.0 ppb — beneath the 15 ppb federal action level and under the 5 ppb watch threshold.
See the trend ↓1,4-Dioxane is approaching its limit
Measured at 0.35 µg/L — 100% of the 0.35 µg/L limit. Within the rules, but with less headroom than you'd want.
See the ledger ↓Pearl Harbor's drinking water received a grade of A (94.8 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 65,230 residents using groundwater.
Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. PFAS testing under UCMR 5 found no detectable forever chemicals. The system has 11 violations on record, including 2 health-based violations. 2 remain unresolved.
Pearl Harbor ranks #18 out of 64 cities in Hawaii for water quality, placing it mid-range in the state. Pearl Harbor relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff. Hexavalent chromium (chromium-6) was detected at 2.30 µg/L in UCMR 3 testing. While below California's 10 µg/L limit and with no federal MCL set, residents sensitive to this contaminant may consider reverse osmosis filtration.
02What's in Pearl Harbor's water
Every contaminant flagged in Pearl Harbor, on one shared scale: distance to its own legal limit. The red line is the limit — anything past it is out of compliance, and the closer a bar gets, the less headroom the system has.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 0.0 | 15 | ppb | Inorganic | Safe |
| 11Cl-PF3OUdS | ND | HI | µg/L | PFAS | Not Detected |
| 4:2 FTS | ND | HI | µg/L | PFAS | Not Detected |
| 6:2 FTS 6:2 FTSPFAS A fluorotelomer sulfonate commonly found at sites contaminated with aqueous film-forming foam (AFFF) used in firefighting. Health EffectsPotential liver toxicity and endocrine disruption. Less studied but identified as a contaminant of concern. EPA LimitNo individual MCL (not yet regulated) Common SourcesFirefighting foam (AFFF), airports, military bases, and industrial facilities. | ND | HI | µg/L | PFAS | Not Detected |
| 8:2 FTS | ND | HI | µg/L | PFAS | Not Detected |
| 9Cl-PF3ONS | ND | HI | µg/L | PFAS | Not Detected |
| ADONA | ND | HI | µg/L | PFAS | Not Detected |
| HFPO-DA HFPO-DA (GenX)PFAS A replacement for PFOA in manufacturing, marketed as safer but still a persistent "forever chemical." Also known as GenX. Health EffectsLiver and kidney effects, reproductive toxicity, immune system effects, and potential cancer risk. EPA Limit10 ppt MCL Common SourcesFluoropolymer manufacturing (used as PFOA replacement), industrial wastewater discharge. | ND | 0.01 | µg/L | PFAS | Not Detected |
| lithium LithiumInorganic A naturally occurring alkali metal found in groundwater. Monitored under UCMR 5 to assess occurrence in drinking water. Health EffectsKidney effects at high doses. Low-level exposure effects under study; some research suggests neurological effects. EPA LimitNo MCL (monitoring only under UCMR 5) Common SourcesNatural mineral deposits, geothermal water, and industrial discharge. | ND | HI | µg/L | PFAS | Not Detected |
| NEtFOSAA | ND | HI | µg/L | PFAS | Not Detected |
| NFDHA | ND | HI | µg/L | PFAS | Not Detected |
| NMeFOSAA | ND | HI | µg/L | PFAS | Not Detected |
| PFBA PFBAPFAS One of the shortest-chain PFAS compounds. Very mobile in water and difficult to remove with standard filtration. Health EffectsThyroid effects, potential developmental toxicity. Shorter half-life in body than long-chain PFAS. EPA LimitNo individual MCL (not yet regulated) Common SourcesDegradation of longer-chain PFAS, industrial discharge, and firefighting foam. | ND | HI | µg/L | PFAS | Not Detected |
| PFBS PFBSPFAS A short-chain PFAS used as a replacement for PFOS. While it clears the body faster than long-chain PFAS, it still persists in the environment. Health EffectsThyroid effects, reproductive and developmental toxicity, kidney effects. EPA LimitPart of Hazard Index (1.0) Common SourcesIndustrial discharge, firefighting foam, and as a replacement chemical in manufacturing. | ND | HI | µg/L | PFAS | Not Detected |
| PFDA | ND | HI | µg/L | PFAS | Not Detected |
| PFDoA | ND | HI | µg/L | PFAS | Not Detected |
| PFEESA | ND | HI | µg/L | PFAS | Not Detected |
| PFHpA PFHpAPFAS A medium-chain PFAS compound found in various environmental samples. Less studied than PFOA/PFOS but still considered a contaminant of concern. Health EffectsLiver effects, potential developmental toxicity, and endocrine disruption. EPA LimitPart of Hazard Index (1.0) Common SourcesDegradation of longer-chain PFAS, industrial discharge, and contaminated water sources. | ND | HI | µg/L | PFAS | Not Detected |
| PFHpS | ND | HI | µg/L | PFAS | Not Detected |
| PFHxA PFHxAPFAS A short-chain PFAS replacement chemical widely used after manufacturers phased out longer-chain PFAS. Very commonly detected in water. Health EffectsLiver and kidney effects, potential thyroid disruption. Considered less toxic than long-chain PFAS but still persistent. EPA LimitNo individual MCL (not yet regulated) Common SourcesIndustrial processes, firefighting foam (AFFF), food packaging, and textile treatment. | ND | HI | µg/L | PFAS | Not Detected |
| PFHxS PFHxSPFAS A medium-chain PFAS found in firefighting foam and consumer products. It has a long half-life in the human body, similar to long-chain PFAS. Health EffectsImmune system effects, thyroid disruption, and potential reproductive and developmental harm. EPA LimitPart of Hazard Index (1.0) Common SourcesFirefighting foam (AFFF), waterproof textiles, food packaging, and industrial discharge. | ND | HI | µg/L | PFAS | Not Detected |
| PFMBA | ND | HI | µg/L | PFAS | Not Detected |
| PFMPA | ND | HI | µg/L | PFAS | Not Detected |
| PFNA PFNAPFAS A long-chain PFAS compound used in manufacturing fluoropolymers. It bioaccumulates in the body and is very persistent in the environment. Health EffectsDevelopmental effects, liver toxicity, immune suppression, and potential cancer risk. EPA LimitPart of Hazard Index (1.0) Common SourcesFluoropolymer manufacturing, industrial emissions, and contaminated water sources. | ND | HI | µg/L | PFAS | Not Detected |
| PFOA PFOAPFAS A long-chain PFAS ("forever chemical") once widely used in nonstick coatings and firefighting foam. It persists in the body and environment for years. Health EffectsLinked to kidney and testicular cancer, thyroid disease, elevated cholesterol, and reproductive issues. EPA Limit4.0 ppt MCL Common SourcesIndustrial discharge, firefighting foam (AFFF), nonstick cookware manufacturing, and contaminated groundwater. | ND | 0.004 | µg/L | PFAS | Not Detected |
| PFOS PFOSPFAS A long-chain PFAS compound historically used in stain-resistant coatings and firefighting foam. One of the most studied and persistent PFAS chemicals. Health EffectsLiver damage, immune system suppression, thyroid disruption, increased cholesterol, and potential cancer risk. EPA Limit4.0 ppt MCL Common SourcesFirefighting foam (AFFF), industrial sites, stain-resistant fabric treatments, and contaminated groundwater. | ND | 0.004 | µg/L | PFAS | Not Detected |
| PFPeA PFPeAPFAS A short-chain PFAS compound commonly detected in drinking water. One of the most frequently found PFAS in UCMR 5 monitoring. Health EffectsLess studied than PFOA/PFOS. Potential liver and thyroid effects. Research is ongoing. EPA LimitNo individual MCL (not yet regulated) Common SourcesIndustrial discharge, firefighting foam degradation, and consumer products. | ND | HI | µg/L | PFAS | Not Detected |
| PFPeS | ND | HI | µg/L | PFAS | Not Detected |
| PFTA | ND | HI | µg/L | PFAS | Not Detected |
| PFTrDA | ND | HI | µg/L | PFAS | Not Detected |
| PFUnA | ND | HI | µg/L | PFAS | Not Detected |
Cities ranked by 90th-percentile lead PF PFAS in Hawaii
Cities ranked by compounds detected Cu Copper in Hawaii
Cities ranked by 90th-percentile copper
03Pearl Harbor's ten-year track record
Each box is one year. A green check means no EPA violations; a numbered badge counts that year's violations — red if any were health-based, amber if they were monitoring or paperwork issues. The system has 11 violations on record, including 2 health-based violations. 2 remain unresolved.
8 of the last ten years were clean. The numbered years had EPA violations — red when any were health-based, amber when they were paperwork or missed-testing issues.
▼ Down 2.5 ppb since 1992. Latest reading: 0 ppb (2023) — 0% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Pearl Harbor's water comes from
Pearl Harbor's drinking water is drawn from underground aquifers through wells.
Groundwater
Underground aquifers reached by wells — naturally filtered, but can carry minerals like arsenic and nitrate.
Local treatment
Groundwater generally needs less treatment — typically disinfection and, where needed, mineral removal.
1 system
1 water system, operated under federal ownership.
65,230 people
Residents served across Pearl Harbor's service area.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals. Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds. The system is operated by federal ownership and serves approximately 65,230 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| JOINT BASE PEARL HARBOR-HICKAM | HI0000360 | 65,230 | Groundwater |
05How Pearl Harbor compares
Scores for nearby Hawaii cities on one line, with the average marked.
dashed line = Hawaii average (90/100)
Pearl Harbor scores 94.8/100 — on par with the Hawaii average of 90/100. It outscores 9 of 10 nearby cities. Full Hawaii rankings →
91.1 / 100AWaipahu-Ewa-Waianae, HI
92.8 / 100AWailuku, HI
91.4 / 100AMililani Bws, HI
97.5 / 100ASchofield Barracks, HI
91.8 / 100AHilo, HI
91.7 / 100
Compare all cities in the county — grades, violations, and contaminant data side by side.→
06What to do at home
Steps matched to what testing actually found in Pearl Harbor's water — not generic advice.
A basic carbon filter still helps
Pearl Harbor's water meets federal standards, but a simple carbon filter improves taste and adds a margin of safety against short-term issues.
Compare tested filters →Read your utility's annual report
Every utility must publish a yearly Consumer Confidence Report with its own testing results. It pairs well with the independent data on this page.
How to read a CCR →Watch for Pearl Harbor alerts
We refresh EPA data monthly and surface new violations, advisories, and boil-water notices for your county on this page.
All water alerts →Frequently asked questions
Is Pearl Harbor, HI tap water safe to drink?
Pearl Harbor's water quality earned a grade of A (94.8/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #18 out of 64 cities tested in Hawaii.
What contaminants are in Pearl Harbor's water?
Lead was measured at 0.0 ppb (90th percentile). No PFAS compounds were detected. 11 violations are on record.
How is Pearl Harbor's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Pearl Harbor?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Pearl Harbor's water come from?
Pearl Harbor's water is sourced from Groundwater. The city has 1 water system serving approximately 65,230 residents.
What health violations has Pearl Harbor's water system had?
Pearl Harbor has 2 health-based violations on record. The most recent violation was recorded in November 2021. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 2 violations remain unresolved.
Is Pearl Harbor's groundwater at risk of contamination?
Pearl Harbor uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 11 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Pearl Harbor's water compare to other cities?
Pearl Harbor ranks #18 out of 64 cities in Hawaii (better than 72% of state cities) and #408 out of 15382 cities nationally (97th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.