Coupeville, Washington Tap Water Quality

24,126 people served · 100 water systems

Failing

Satellite view of Coupeville, Washington

Satellite imagery via Esri World Imagery — approximate city center, not a facility address.

Coupeville, Washington is a small city with 24,126 residents served by 100 distinct public water systems. Water service covers ZIP code 98239.

Coupeville has accumulated a significant number of EPA health-based violations. Reviewing the contaminants involved, requesting your utility's Consumer Confidence Report, and using certified point-of-use filtration is strongly advisable.

EPA reporting identifies Nitrate, Arsenic, Total Trihalomethanes (TTHMs), Haloacetic Acids (HAA5), and Coliform Bacteria among the regulated contaminants associated with Coupeville's recent health-based violations. Each contaminant has different sources, health implications, and recommended mitigation steps — links to the full EPA reference for each are listed alongside the violation history below.

Coupeville's 77 violations is above the Washington average of 1.8 per city — worth reviewing the contaminant breakdown below.

Last updated: 2026-05-18 · Source: EPA SDWIS

Location

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Centered on ZIP-code centroids of water systems serving this city.

ZIP Codes Served

98239

Health-Based Violations (Last 5 Years)

EPA Maximum Contaminant Level exceedances reported by water systems serving Coupeville. Each entry explains the contaminant, the health risk, and recommended precautions, and links to a full guide.

Arsenicchemical

EPA Code 1005 · Maximum Contaminant Level Exceedance

violations

EPA Limit

0.01 mg/L

Last Reading

.0272 MG/L

First Reported

Jan 2021

Most Recent

Oct 2025

What this violation means

Arsenic is a known human carcinogen that occurs naturally in groundwater across many parts of the United States, especially the Southwest and parts of New England. Long-term exposure even at low levels has been linked to bladder, lung, and skin cancer, as well as cardiovascular disease and developmental effects in children.

Recommended precautions

→Reverse osmosis filtration removes arsenic effectively.
→Distillation also removes arsenic — point-of-use distillers work for drinking and cooking water.
→Boiling does NOT remove arsenic. It actually concentrates it as water evaporates.
→If your well water has arsenic, test annually and treat at the point of entry.

Read the complete guide to Arsenic

Total Trihalomethanes (TTHMs)disinfectant

EPA Code 2950 · Maximum Contaminant Level Exceedance

violations

EPA Limit

0.08 mg/L

Last Reading

122.25 UG/L

First Reported

Apr 2021

Most Recent

Oct 2025

What this violation means

Total Trihalomethanes (TTHMs) form when chlorine reacts with naturally occurring organic matter — leaves, soil, algae — in source water. They are among the most commonly reported violations because utilities pulling from surface water (rivers, lakes, reservoirs) struggle to balance disinfection with byproduct formation. Long-term exposure has been linked to bladder cancer and adverse pregnancy outcomes.

Recommended precautions

→Activated carbon filters (pitcher, faucet, or under-sink) effectively reduce TTHMs.
→Letting water sit uncovered allows TTHMs to off-gas — leave a pitcher in the fridge for several hours.
→Shower with the bathroom fan on; TTHMs can volatilize into the air during hot showers.
→Boiling reduces TTHMs through volatilization, but only after extended boiling.

Read the complete guide to Total Trihalomethanes (TTHMs)

Haloacetic Acids (HAA5)disinfectant

EPA Code 2456 · Maximum Contaminant Level Exceedance

violations

EPA Limit

0.06 mg/L

Last Reading

86.03 UG/L

First Reported

Jan 2021

Most Recent

Oct 2025

What this violation means

Haloacetic Acids (HAA5) are the second major group of disinfection byproducts after TTHMs. They form by the same mechanism — chlorine reacting with organic matter — and pose similar long-term cancer risks. Utilities are required to test quarterly at distribution-system locations to track HAA5 levels.

Recommended precautions

→Activated carbon filtration removes most HAA5.
→Reverse osmosis is highly effective.
→Unlike TTHMs, HAA5 do not significantly off-gas. Use treatment rather than aeration.
→Long-term ingestion is the primary concern, not short-term skin contact.

Read the complete guide to Haloacetic Acids (HAA5)

Nitratechemical

EPA Code 1040 · Maximum Contaminant Level Exceedance

violation

EPA Limit

10 mg/L

Last Reading

16 MG/L

First Reported

Jan 2025

Most Recent

Jan 2025

What this violation means

Nitrate contamination is most acute in agricultural regions where fertilizer and animal waste leach into groundwater. The immediate risk is to formula-fed infants under 6 months — high nitrate levels prevent their blood from carrying oxygen, causing 'blue baby syndrome.' Pregnant women should also avoid high-nitrate water.

Recommended precautions

→Never give untreated high-nitrate water to infants — use bottled water for formula.
→Boiling does NOT remove nitrate. Boiling concentrates it.
→Reverse osmosis, ion exchange, or distillation are the only effective home treatments.
→Private well owners in farming areas should test annually for nitrate.

Read the complete guide to Nitrate

Coliform Bacteriamicrobial

EPA Code 8000 · Maximum Contaminant Level Exceedance

violation

EPA Limit

0 per 100 mL presence/absence

Last Reading

—

First Reported

Nov 2023

Most Recent

Nov 2023

What this violation means

Total coliform bacteria are themselves usually harmless, but their presence signals that the water distribution system has a vulnerability — typically a cracked pipe, loss of pressure, or back-siphonage — that could allow disease-causing pathogens to enter. Repeated coliform-positive samples trigger mandatory utility investigation.

Recommended precautions

→If your utility issues a boil-water advisory, boil all drinking and cooking water for at least one minute.
→Use bottled water until the advisory is lifted.
→Ice from icemakers and beverages made before the advisory should be discarded.
→UV light and chlorination both kill coliform bacteria — most home filters do not.

Read the complete guide to Coliform Bacteria

Source: EPA Safe Drinking Water Information System (SDWIS). Health-based violations only. Older violations may have been resolved; check your utility's most recent Consumer Confidence Report for current status.

Water Systems Serving Coupeville

DOYLE WATER ASSOCIATION

PWSID: WA5319155

36 served

EAGLE VALLEY WATER SYSTEM

PWSID: WA5302217

135 served

Northwest Water

PWSID: WA5302287

99 served

ADAMS RD COMMUNITY ASSN

PWSID: WA5301977

59 served

CAMANO HILLS WATER COMPANY INC

PWSID: WA5301429

286 served

POLNELL LANDING WATER ASSOC.

PWSID: WA5355476

24 served

RACE LAGOON WATER ASSOCIATION

PWSID: WA5303741

141 served

CARE FREE ACRES

PWSID: WA5311135

30 served

CAMALOCH ASSOCIATION

PWSID: WA5310580

825 served

SILVER LAKE RD ACREAGE TRACTS

PWSID: WA5310587

73 served

KINETH CLAIM COMMUNITY WATER ASSOC.

PWSID: WA5314371

65 served

COUNTRY PLACE MOBILE HOME PARK

PWSID: WA5312003

200 served

MAPLE HILL PARK

PWSID: WA5309356

35 served

1 violation

CAMANO VISTA WATER DISTRICT

PWSID: WA5310748

591 served

CAMANO WATER ASSOCIATION

PWSID: WA5310750

2,592 served

COMBINED WATER SYSTEM

PWSID: WA5305795

435 served

BEACHWOOD WATER COMPANY

PWSID: WA5304980

90 served

9 violations

WOODGLEN PRD WATER SYSTEM

PWSID: WA5306529

40 served

ROCKY POINT COMMUNITY CLUB

PWSID: WA5304629

320 served

West View Apartments Water System

PWSID: WA5305570

54 served

FAIRWAY ESTATES INC

PWSID: WA5324524

100 served

FIRCREST COMMUNITY WATER SYSTEM

PWSID: WA5324529

150 served

CROSSWOODS WATER COMPANY

PWSID: WA5316274

420 served

CRESCENT ACRES WATER ASSOCIATION

PWSID: WA5315930

64 served

DEVRIES ROAD COMMUNITY ASSN

PWSID: WA5315948

76 served

18 violations

EASTGATE

PWSID: WA5322030

76 served

11 violations

COUPEVILLE TOWN OF

PWSID: WA5315550

4,077 served

DRIFTWOOD HEIGHTS ASSOCIATION

PWSID: WA5319948

311 served

WEST BEACH ROAD ASSOCIATION

PWSID: WA5317970

37 served

CORNET BAY HEIGHTS WATER ASSN INC

PWSID: WA5315020

99 served

ELGERWOOD MAINTENANCE ASSOCIATION

PWSID: WA5309131

112 served

BUSH POINT TRAC PARK

PWSID: WA5309900

111 served

DAVIS LANDING WATER SYSTEM

PWSID: WA5318140

74 served

FIR GROVE MOBILE PARK

PWSID: WA5325137

65 served

LAKEWOOD WEST WATER ASSN.

PWSID: WA5344627

75 served

HOLMES HARBOR WATER CO

PWSID: WA5333870

110 served

WHIDBEY WEST WATER ASSOC.

PWSID: WA5336314

415 served

7 violations

Bets Water System

PWSID: WA5339991

50 served

LAKE GROVE WATER ASSOCIATION

PWSID: WA5343940

134 served

Sky Meadows Community Assoc.

PWSID: WA5342705

58 served

SUNLIGHT SHORES COUNTRY CLUB

PWSID: WA5333039

150 served

HILLCREST HOMESTEAD TRACTS WATER

PWSID: WA5333120

29 served

MECCA COMMUNITY ASSOCIATION

PWSID: WA5322888

619 served

AHEARN WATER SYSTEM

PWSID: WA5325384

91 served

SLEEPER ACRES COMM. ASSOC. INC.

PWSID: WA5329901

56 served

WILDES GROVE COMMUNITY WATER SYS

PWSID: WA5326911

33 served

LAKEVIEW TERRACE

PWSID: WA5345364

140 served

MABANA SHORES ASSOCIATION

PWSID: WA5349600

68 served

GOSS LAKE PARK COMMUNITY

PWSID: WA5328575

285 served

LEISURE ACRES WATER ASSOCIATION

PWSID: WA5346695

35 served

IDLEWOOD COMMUNITY

PWSID: WA5335370

111 served

LOST LAKE PROPERTY OWNERS ASSN

PWSID: WA5348345

736 served

USELESS BAY SHORES

PWSID: WA5333261

56 served

PINE TERRACE WATER ASSOCIATION

PWSID: WA5367600

181 served

1 violation

MARINERS COVE BEACH CLUB INC

PWSID: WA5351730

300 served

LIGHTHOUSE SHORES

PWSID: WA5347200

152 served

LIVINGSTON BAY COMMUNITY ASSN

PWSID: WA5347628

120 served

POLNELL HEIGHTS WATER ASSOCIATION

PWSID: WA5368370

65 served

POLNELL SHORES COMM ORG INC

PWSID: WA5368373

195 served

PONDILLA ESTATES COMMUNITY ASSOC

PWSID: WA5368430

52 served

RACE LAGOON HEIGHTS ASSOCIATION

PWSID: WA5370650

157 served

HIDE-AWAY WATER COMPANY INC

PWSID: WA5366586

240 served

5 violations

PARKWOOD MANOR MHP

PWSID: WA5366218

301 served

POSSESSION SHORES INC

PWSID: WA5369020

150 served

Mutiny Bay Park Water Association

PWSID: WA5357740

156 served

FORT KNOX MOBILE HOME PARK

PWSID: WA5359576

79 served

NORTHGATE TERRACE COMMUNITY CLUB

PWSID: WA5361750

750 served

SUNSET WEST

PWSID: WA5361761

75 served

1 violation

PHEASANT FARM ACRES

PWSID: WA5367187

95 served

RHODENA BEACH WATER DISTRICT

PWSID: WA5372150

152 served

MEADOW RIDGE

PWSID: WA5353213

175 served

LONG POINT WATER COMPANY INC

PWSID: WA5348050

182 served

1 violation

SARATOGA WATER DISTRICT

PWSID: WA5376300

477 served

10 violations

NORCLIFFE WATER ASSOCIATION

PWSID: WA5384566

57 served

SUMMERLAND

PWSID: WA5384903

85 served

Whispering Pines Homeowners Coop

PWSID: WA5388215

116 served

WOODLAND ESTATES

PWSID: WA5398183

106 served

SUNVISTA SUNLIGHT BEACH HOA

PWSID: WA5385160

500 served

SUBURBAN MOBILE PARK

PWSID: WA5384730

60 served

1 violation

SCATCHET HEAD WATER DISTRICT

PWSID: WA5376470

900 served

1 violation

SHIRONA WATER SYSTEM

PWSID: WA5378373

243 served

1 violation

SILVER SPRINGS ESTATES COMM ASSN

PWSID: WA5379276

61 served

SKYLINE WEST COMMUNITY CLUB

PWSID: WA5380212

109 served

SHANGRI-LA SHORES INC

PWSID: WA5377850

56 served

WEST RIDGE WATER SYSTEM

PWSID: WA5394942

275 served

SIERRA COUNTRY CLUB

PWSID: WA5378975

400 served

9 violations

WILDERNESS RIDGE COMMUNITY CLUB

PWSID: WA5396876

664 served

GEORGETOWN WATER ASSOCIATION

PWSID: WA5312636

32 served

1 violation

DEER LAKE ESTATES

PWSID: WA5318440

55 served

TAYLOR ROAD WATER SYSTEM

PWSID: WA5387195

50 served

SUNSET DEVELOPMENT COMM CLUB

PWSID: WA5386075

92 served

VALLEY HIGH PARK

PWSID: WA5390976

141 served

WAYNES RIDGE WATER ASSOC

PWSID: WA5393909

108 served

WAGON WHEEL

PWSID: WA5392070

150 served

Eaglecrest Water & Road Association

PWSID: WA5326091

28 served

WHIDBEY HIGHLANDS WATER ASSOC

PWSID: WA5396050

62 served

WHIDBEY SHORES WATER SYSTEM

PWSID: WA5396070

262 served

THUNDER RIDGE WATER SYSTEM

PWSID: WA5388200

145 served

TERONDA WEST COUNTRY CLUB ASSN.

PWSID: WA5387520

127 served

ROCKAWAY BEACH COMMUNITY ASSN

PWSID: WA5306014

35 served

What Can You Do?

✅ Request your utility's annual Consumer Confidence Report (CCR) — required by law.
✅ Use an NSF-certified water filter if violations involve lead, arsenic, or PFAS.
✅ Run cold water for 30 seconds before drinking if you have older plumbing (reduces lead).
✅ Check back monthly — we update data from the EPA every 30 days.

About this data

This overview reflects EPA SDWIS data published as of 2026-05-18. It covers active Community Water Systems (CWS) that exceeded federal Maximum Contaminant Levels during the past five-year EPA reporting window. For up-to-the-minute information, request a current Consumer Confidence Report from your utility, or review the EPA's public dashboard.

Frequently Asked Questions

Is Coupeville, Washington tap water safe to drink?▼

This city's water had numerous EPA violations in the last 5 years. Consider filtered water.

How many EPA violations does Coupeville have?▼

Coupeville has 77 EPA health-based water violations in the last 5 years across 100 water systems serving 24,126 people.

What contaminants have been found in Coupeville water?▼

The following EPA-regulated contaminants have been detected: 1040, 1005, 2950, 2456, 8000. View details about each contaminant, health effects, and recommended precautions above in the violations table.

Should I use a water filter in Coupeville?▼

Using an NSF-certified water filter is recommended if your area has violations involving lead, arsenic, or PFAS. For other contaminants, consult your local water utility. Check the annual Consumer Confidence Report (CCR) for detailed guidance.

What should I do if there are violations in Coupeville?▼

Request your water utility's annual Consumer Confidence Report (CCR), which is required by the EPA. Follow the utility's guidance on boil water advisories. Run cold water for 30 seconds before drinking if you have older plumbing. Use an NSF-certified filter if needed based on your water system's violations.