Is Coupeville, WA Tap Water Safe to Drink?
Graded F — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
38/100
waterverge.com Coupeville, WA — Water Quality Report
Coupeville's drinking water received a grade of F (38 out of 100), indicating failing water quality. The city's 110 water systems serve approximately 25,056 residents using groundwater.
Lead levels were measured at 1.6 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 7 PFAS compounds, with levels exceeding EPA maximum contaminant levels in the water supply.
The system has 4333 violations on record, including 448 health-based violations. 306 remain unresolved.
What to know about Coupeville's water
Coupeville ranks #288 out of 294 cities in Washington for water quality, placing it among the lowest-rated in the state.
Coupeville 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.
Of particular concern: PFAS "forever chemical" levels exceed the 2024 EPA maximum contaminant levels. These synthetic compounds don't break down naturally and require specialized filtration such as reverse osmosis or granular activated carbon.
The system has seen 778 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Coupeville, WA water safe to drink?
Coupeville's drinking water has significant quality concerns based on EPA testing data. With a grade of F (38/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 110 water systems serve approximately 25,056 residents using groundwater (wells).
Recent water quality updates for Coupeville
A timeline of significant water quality events, violations, and data updates.
PFAS levels exceed EPA maximum contaminant levels. Reverse osmosis or activated carbon filtration recommended.
Latest EPA compliance and testing data incorporated into Coupeville's water quality assessment. Grade: F (38/100).
5 health-based. Contaminants: Vinyl chloride, Methoxychlor, 2,4,5-TP.
4 health-based. Contaminants: Consumer Confidence Rule, Toxaphene, Heptachlor.
5 health-based. Contaminants: Nitrate, Arsenic, TTHM.
Federal disaster declaration (FEMA DR-4650). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Coupeville's water supply.
Well within EPA limits.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
PFAS "forever chemicals" exceed EPA maximum contaminant levels. Reverse osmosis or granular activated carbon filtration strongly recommended.
PFAS "forever chemicals" detected
UCMR 5 testing found 7 PFAS compounds in Coupeville's water supply. PFAS are synthetic chemicals that persist indefinitely in the environment and the human body.
Violation history
Coupeville's water system has 4,333 total violations on record, including 448 health-based violations. 306 remain unresolved. 778 violations were issued in the last 5 years.
Flood & environmental risk
Island County has experienced 6 federally declared disasters since 1990. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.
Where does Coupeville's water come from?
Coupeville's drinking water comes from groundwater (wells), supplied by 110 water systems serving approximately 25,056 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What Coupeville residents can do
Recommended: Reverse osmosis system. This addresses the specific contaminants found in Coupeville's water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Coupeville's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Forever chemicals overview
National PFAS report →Violation summary
Violations & advisories
Top industrial polluters within 10 miles of Coupeville
Industrial polluters nearby
Reported releases to surface water by facilities near Coupeville, ranked by pounds discharged annually.
Total reported releases to surface water: 0 lbs
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
US NAVY NAS WHIDBEY ISLAND AULT FIELD OAK HARBOR, WA982783500 | Lead | 0 | 8.7 mi |
TECHNICAL SERVICES INC OAK HARBOR, WA98277 | — | — | 6.9 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Superfund sites within 10 miles of Coupeville
Superfund sites nearby
Federally tracked hazardous-waste sites on the EPA National Priorities List. Proximity does not necessarily indicate tap-water contamination — the connection depends on hydrology and treatment.
- NAVAL AIR STATION WHIDBEY ISLAND AULT FIELD8.7 mi
Source: EPA Superfund National Priorities List
Flood & disaster history
Island County has experienced 6 federally declared disasters since 1990. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Coupeville's water supply, we recommend the following filter types.
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. | 1.6 | 15 | ppb | Inorganic | Safe |
| Copper (90th percentile) CopperInorganic A metal that enters drinking water mainly through corrosion of copper plumbing. Small amounts are essential for health, but excess levels are harmful. Health EffectsGastrointestinal distress (nausea, vomiting, diarrhea) at short-term high levels; liver and kidney damage from long-term exposure. EPA Limit1.3 mg/L action level Common SourcesCorrosion of copper household plumbing, erosion of natural deposits. | 1.78 | 1.3 | mg/L | Inorganic | Over Limit |
| 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. | 0.005 | HI | µg/L | PFAS | 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. | 0.007 | HI | µg/L | PFAS | 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. | 0.003 | HI | µg/L | PFAS | 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. | 0.017 | HI | µg/L | PFAS | 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. | 0.004 | HI | µg/L | PFAS | 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. | 0.010 | 0.004 | µg/L | PFAS | Over MCL |
| 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. | 0.012 | HI | µg/L | PFAS | 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 |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how Coupeville compares by contaminant
Explore where Coupeville ranks among all Washington cities for specific contaminants.
Water source & infrastructure
Where Coupeville's water comes from
Coupeville's drinking water is drawn from underground aquifers through wells.
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 local government ownership and serves approximately 25,056 people through 110 water systems.
Water systems serving Coupeville
| System Name | PWSID | Population | Source |
|---|---|---|---|
| COUPEVILLE TOWN OF | WA5315550 | 4,077 | GW |
| CAMANO WATER ASSOCIATION | WA5310750 | 2,592 | GW |
| SCATCHET HEAD WATER DISTRICT | WA5376470 | 900 | GW |
| CAMALOCH ASSOCIATION | WA5310580 | 825 | GW |
| NORTHGATE TERRACE COMMUNITY CLUB | WA5361750 | 750 | GW |
| LOST LAKE PROPERTY OWNERS ASSN | WA5348345 | 736 | GW |
| WILDERNESS RIDGE COMMUNITY CLUB | WA5396876 | 664 | GW |
| MECCA COMMUNITY ASSOCIATION | WA5322888 | 619 | GW |
| CAMANO VISTA WATER DISTRICT | WA5310748 | 591 | GW |
| SUNVISTA SUNLIGHT BEACH HOA | WA5385160 | 500 | GW |
| SARATOGA WATER DISTRICT | WA5376300 | 477 | GW |
| COMBINED WATER SYSTEM | WA5305795 | 435 | GW |
| CROSSWOODS WATER COMPANY | WA5316274 | 420 | GW |
| WHIDBEY WEST WATER ASSOC. | WA5336314 | 415 | GW |
| SIERRA COUNTRY CLUB | WA5378975 | 400 | GW |
| ROCKY POINT COMMUNITY CLUB | WA5304629 | 320 | GW |
| DRIFTWOOD HEIGHTS ASSOCIATION | WA5319948 | 311 | GW |
| PARKWOOD MANOR MHP | WA5366218 | 301 | GW |
| MARINERS COVE BEACH CLUB INC | WA5351730 | 300 | GW |
| CAMANO HILLS WATER COMPANY INC | WA5301429 | 286 | GW |
| GOSS LAKE PARK COMMUNITY | WA5328575 | 285 | GW |
| WEST RIDGE WATER SYSTEM | WA5394942 | 275 | GW |
| WHIDBEY SHORES WATER SYSTEM | WA5396070 | 262 | GW |
| SHIRONA WATER SYSTEM | WA5378373 | 243 | GW |
| HIDE-AWAY WATER COMPANY INC | WA5366586 | 240 | GW |
| JUNIPER BEACH WATER DISTRICT | WA5337250 | 213 | GW |
| COUNTRY PLACE MOBILE HOME PARK | WA5312003 | 200 | GW |
| POLNELL SHORES COMM ORG INC | WA5368373 | 195 | GW |
| HARRIS CUSTER ESTATES WATER ASSN | WA5317035 | 194 | GW |
| LONG POINT WATER COMPANY INC | WA5348050 | 182 | GW |
| PINE TERRACE WATER ASSOCIATION | WA5367600 | 181 | GW |
| MEADOW RIDGE | WA5353213 | 175 | GW |
| RACE LAGOON HEIGHTS ASSOCIATION | WA5370650 | 157 | GW |
| Mutiny Bay Park Water Association | WA5357740 | 156 | GW |
| LIGHTHOUSE SHORES | WA5347200 | 152 | GW |
| RHODENA BEACH WATER DISTRICT | WA5372150 | 152 | GW |
| FIRCREST COMMUNITY WATER SYSTEM | WA5324529 | 150 | GW |
| SUNLIGHT SHORES COUNTRY CLUB | WA5333039 | 150 | GW |
| POSSESSION SHORES INC | WA5369020 | 150 | GW |
| WAGON WHEEL | WA5392070 | 150 | GW |
| THUNDER RIDGE WATER SYSTEM | WA5388200 | 145 | GW |
| RACE LAGOON WATER ASSOCIATION | WA5303741 | 141 | GW |
| VALLEY HIGH PARK | WA5390976 | 141 | GW |
| LAKEVIEW TERRACE | WA5345364 | 140 | GW |
| EAGLE VALLEY WATER SYSTEM | WA5302217 | 135 | GW |
| LAKE GROVE WATER ASSOCIATION | WA5343940 | 134 | GW |
| TERONDA WEST COUNTRY CLUB ASSN. | WA5387520 | 127 | GW |
| CAMPO HACIENDA | WA5310992 | 123 | GW |
| LIVINGSTON BAY COMMUNITY ASSN | WA5347628 | 120 | GW |
| Whispering Pines Homeowners Coop | WA5388215 | 116 | GW |
| PIONEER PARK WATER SYSTEM | WA5367717 | 115 | GW |
| ELGERWOOD MAINTENANCE ASSOCIATION | WA5309131 | 112 | GW |
| BUSH POINT TRAC PARK | WA5309900 | 111 | GW |
| IDLEWOOD COMMUNITY | WA5335370 | 111 | GW |
| HOLMES HARBOR WATER CO | WA5333870 | 110 | GW |
| SKYLINE WEST COMMUNITY CLUB | WA5380212 | 109 | GW |
| WAYNES RIDGE WATER ASSOC | WA5393909 | 108 | GW |
| WOODLAND ESTATES | WA5398183 | 106 | GW |
| FAIRWAY ESTATES INC | WA5324524 | 100 | GW |
| Northwest Water | WA5302287 | 99 | GW |
| CORNET BAY HEIGHTS WATER ASSN INC | WA5315020 | 99 | GW |
| PHEASANT FARM ACRES | WA5367187 | 95 | GW |
| SUNSET DEVELOPMENT COMM CLUB | WA5386075 | 92 | GW |
| AHEARN WATER SYSTEM | WA5325384 | 91 | GW |
| BEACHWOOD WATER COMPANY | WA5304980 | 90 | GW |
| PATTONS RETREAT WATER ASSN | WA5366588 | 90 | GW |
| SUMMERLAND | WA5384903 | 85 | GW |
| FORT KNOX MOBILE HOME PARK | WA5359576 | 79 | GW |
| DEVRIES ROAD COMMUNITY ASSN | WA5315948 | 76 | GW |
| EASTGATE | WA5322030 | 76 | GW |
| LAKEWOOD WEST WATER ASSN. | WA5344627 | 75 | GW |
| SUNSET WEST | WA5361761 | 75 | GW |
| DAVIS LANDING WATER SYSTEM | WA5318140 | 74 | GW |
| SILVER LAKE RD ACREAGE TRACTS | WA5310587 | 73 | GW |
| MABANA SHORES ASSOCIATION | WA5349600 | 68 | GW |
| KINETH CLAIM COMMUNITY WATER ASSOC. | WA5314371 | 65 | GW |
| FIR GROVE MOBILE PARK | WA5325137 | 65 | GW |
| POLNELL HEIGHTS WATER ASSOCIATION | WA5368370 | 65 | GW |
| CRESCENT ACRES WATER ASSOCIATION | WA5315930 | 64 | GW |
| CAMPBELLS GLEN | WA5310988 | 62 | GW |
| WHIDBEY HIGHLANDS WATER ASSOC | WA5396050 | 62 | GW |
| SILVER SPRINGS ESTATES COMM ASSN | WA5379276 | 61 | GW |
| SUBURBAN MOBILE PARK | WA5384730 | 60 | GW |
| ADAMS RD COMMUNITY ASSN | WA5301977 | 59 | GW |
| Sky Meadows Community Assoc. | WA5342705 | 58 | GW |
| NORCLIFFE WATER ASSOCIATION | WA5384566 | 57 | GW |
| SLEEPER ACRES COMM. ASSOC. INC. | WA5329901 | 56 | GW |
| USELESS BAY SHORES | WA5333261 | 56 | GW |
| SHANGRI-LA SHORES INC | WA5377850 | 56 | GW |
| DEER LAKE ESTATES | WA5318440 | 55 | GW |
| West View Apartments Water System | WA5305570 | 54 | GW |
| PONDILLA ESTATES COMMUNITY ASSOC | WA5368430 | 52 | GW |
| Bets Water System | WA5339991 | 50 | GW |
| TAYLOR ROAD WATER SYSTEM | WA5387195 | 50 | GW |
| North Beverly Beach Association | WA5311239 | 46 | GW |
| WOODGLEN PRD WATER SYSTEM | WA5306529 | 40 | GW |
| WEST BEACH ROAD ASSOCIATION | WA5317970 | 37 | GW |
| DOYLE WATER ASSOCIATION | WA5319155 | 36 | GW |
| ROCKAWAY BEACH COMMUNITY ASSN | WA5306014 | 35 | GW |
| MAPLE HILL PARK | WA5309356 | 35 | GW |
| LEISURE ACRES WATER ASSOCIATION | WA5346695 | 35 | GW |
| WILDES GROVE COMMUNITY WATER SYS | WA5326911 | 33 | GW |
| GEORGETOWN WATER ASSOCIATION | WA5312636 | 32 | GW |
| CARE FREE ACRES | WA5311135 | 30 | GW |
| LITTLE VALLEY APTS. | WA5322057 | 30 | GW |
| Koontz Ranch Water System | WA53AD532 | 30 | GW |
| HILLCREST HOMESTEAD TRACTS WATER | WA5333120 | 29 | GW |
| Eaglecrest Water & Road Association | WA5326091 | 28 | GW |
| TIMARU COMMUNITY WATER ASSOCIATION | WA5398215 | 27 | GW |
| POLNELL LANDING WATER ASSOC. | WA5355476 | 24 | GW |
How Coupeville compares
Full Washington rankings →Coupeville's score of 38/100 is below the average of 53/100 among major Washington cities. It outscores 2 of 10 nearby cities. 8 of 10 nearby cities score higher.
Nearby cities
View Washington rankings →About Coupeville, WA
Learn more about your water
Guides and resources related to Coupeville's water quality findings.
Explore water quality across Island
Frequently asked questions
Is Coupeville, WA tap water safe to drink?
Coupeville's water quality earned a grade of F (38/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #288 out of 294 cities tested in Washington.
What contaminants are in Coupeville's water?
Lead was measured at 1.6 ppb (90th percentile). 7 PFAS compounds were detected. 4333 violations are on record.
How is Coupeville'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 Coupeville?
PFAS compounds exceed EPA limits — a reverse osmosis or activated carbon filter is recommended.
Where does Coupeville's water come from?
Coupeville's water is sourced from Groundwater. The city has 110 water systems serving approximately 25,056 residents.
What health violations has Coupeville's water system had?
Coupeville has 448 health-based violations on record. The most recent violation was recorded in October 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 306 violations remain unresolved.
Is Coupeville's groundwater at risk of contamination?
Coupeville 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 4333 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.
Why does Coupeville have so many PFAS compounds in its water?
7 different PFAS "forever chemical" compounds were detected in Coupeville's water supply during UCMR 5 testing. PFAS contamination often originates from proximity to military installations (AFFF firefighting foam), airports, industrial manufacturing sites, or wastewater treatment facilities. Some levels exceed the 2024 EPA maximum contaminant levels — a reverse osmosis or NSF-certified activated carbon filter is strongly recommended.
How does Coupeville's water compare to other cities?
Coupeville ranks #288 out of 294 cities in Washington (better than 2% of state cities) and #15370 out of 15744 cities nationally (2th percentile). The grade of F reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.