Water Quality in Oak Harbor, WA (98277)

EPA violation data for public water systems serving ZIP code 98277.

147

Total Violations

Health-Based

121

Monitoring / Reporting

146

Resolved

What does this mean?

146 of 147 violations have been resolved. 26 are health-based violations, meaning contaminant levels exceeded federal safety limits. The remaining 121 are monitoring or reporting violations (missed testing deadlines or late paperwork — not necessarily a water quality issue). Not all violations mean your water is unsafe. The EPA requires reporting even for minor administrative issues.

Water systems: 84 Population served: 32,902

Violations Detail (147 total)

Contaminant	Category	MCL Limit	Measured	Date	Status	Health Effects
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2025	Resolved	N/A
TTHM	Health-Based	N/A	115.9	Jun 30, 2025	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
BHC-GAMMA	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Chlordane	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Pentachlorophenol	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Simazine	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Vinyl chloride	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	Increased risk of cancer
1,2-Dichloroethane	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Heptachlor epoxide	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Heptachlor	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Toluene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
2,4,5-TP	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
1,1,2-Trichloroethane	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Benzene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	Anemia; decrease in blood platelets; increased risk of cancer
Carbon tetrachloride	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	Liver problems; increased risk of cancer
CHLOROBENZENE	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
1,2-Dichloroethane	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Styrene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Ethylbenzene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Styrene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
1,2,4-Trichlorobenzene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Tetrachloroethylene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	Liver problems; increased risk of cancer
Picloram	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
1,1-Dichloroethylene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Dinoseb	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
CHLOROBENZENE	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Trichloroethylene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	Liver problems; increased risk of cancer
o-Dichlorobenzene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
1,2,4-Trichlorobenzene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
DICHLOROMETHANE	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
o-Dichlorobenzene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
1,1,2-Trichloroethane	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
trans-1,2-Dichloroethylene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Dalapon	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Carbon tetrachloride	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	Liver problems; increased risk of cancer
DICHLOROMETHANE	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
p-Dichlorobenzene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
p-Dichlorobenzene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
1,2-Dichloropropane	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Endrin	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
cis-1,2-Dichloroethylene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
1,2-Dichloropropane	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Ethylbenzene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Benzene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	Anemia; decrease in blood platelets; increased risk of cancer
Toluene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
1,1-Dichloroethylene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
1,1,1-Trichloroethane	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Di(2-ethylhexyl) adipate	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Trichloroethylene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	Liver problems; increased risk of cancer
Atrazine	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	Cardiovascular system or reproductive problems
Tetrachloroethylene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	Liver problems; increased risk of cancer
1,1,1-Trichloroethane	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Vinyl chloride	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	Increased risk of cancer
trans-1,2-Dichloroethylene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Methoxychlor	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Toxaphene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Di(2-ethylhexyl) phthalate	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Hexachlorocyclopentadiene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
LASSO	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
HEXACHLOROBENZENE	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Benzo(a)pyrene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
cis-1,2-Dichloroethylene	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2025	Resolved	N/A
TTHM	Health-Based	N/A	114.93	Mar 31, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jan 31, 2025	Resolved	N/A
TTHM	Health-Based	N/A	81.5	Dec 31, 2024	Resolved	N/A
TTHM	Health-Based	N/A	118.8	Dec 31, 2024	Resolved	N/A
TTHM	Health-Based	N/A	82.35	Sep 30, 2024	Resolved	N/A
TTHM	Health-Based	N/A	122.4	Sep 30, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2024	Resolved	N/A
TTHM	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
TTHM	Health-Based	N/A	95.7	Jun 30, 2024	Resolved	N/A
Total Haloacetic Acids (HAA5)	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
TTHM	Health-Based	N/A	132.23	Jun 30, 2024	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Apr 30, 2024	Resolved	N/A
Total Haloacetic Acids (HAA5)	Monitoring	N/A	N/A	Mar 31, 2024	Resolved	N/A
TTHM	Monitoring	N/A	N/A	Mar 31, 2024	Resolved	N/A
TTHM	Health-Based	N/A	82.8	Mar 31, 2024	Resolved	N/A
TTHM	Health-Based	N/A	138.75	Mar 31, 2024	Resolved	N/A
Arsenic	Health-Based	N/A	0.0111	Mar 31, 2024	Resolved	Skin damage; circulatory system problems; increased risk of cancer
Revised Total Coliform Rule	Monitoring	N/A	N/A	Feb 29, 2024	Resolved	N/A
TTHM	Monitoring	N/A	N/A	Dec 31, 2023	Resolved	N/A
Total Haloacetic Acids (HAA5)	Monitoring	N/A	N/A	Dec 31, 2023	Resolved	N/A
TTHM	Health-Based	N/A	120.7	Dec 31, 2023	Resolved	N/A
TTHM	Health-Based	N/A	124.7	Dec 31, 2023	Resolved	N/A
Arsenic	Health-Based	N/A	0.0119	Dec 31, 2023	Resolved	Skin damage; circulatory system problems; increased risk of cancer
TTHM	Health-Based	N/A	92.1	Sep 30, 2023	Resolved	N/A
TTHM	Health-Based	N/A	111.4	Sep 30, 2023	Resolved	N/A
Arsenic	Health-Based	N/A	0.012	Sep 30, 2023	Resolved	Skin damage; circulatory system problems; increased risk of cancer
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2023	Resolved	N/A
TTHM	Monitoring	N/A	N/A	Jun 30, 2023	Resolved	N/A
TTHM	Health-Based	N/A	102	Jun 30, 2023	Resolved	N/A
Total Haloacetic Acids (HAA5)	Monitoring	N/A	N/A	Jun 30, 2023	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2023	Resolved	N/A
Arsenic	Health-Based	N/A	0.0118	Jun 30, 2023	Resolved	Skin damage; circulatory system problems; increased risk of cancer
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2023	Resolved	N/A
TTHM	Health-Based	N/A	98.3	Mar 31, 2023	Resolved	N/A
Arsenic	Health-Based	N/A	0.0114	Mar 31, 2023	Resolved	Skin damage; circulatory system problems; increased risk of cancer
Revised Total Coliform Rule	Monitoring	N/A	N/A	Feb 28, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Feb 28, 2023	Resolved	N/A
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
TTHM	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	N/A
Total Haloacetic Acids (HAA5)	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	N/A
TTHM	Health-Based	N/A	106.5	Dec 31, 2022	Resolved	N/A
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Revised Total Coliform Rule	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	N/A
Nitrate	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Revised Total Coliform Rule	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	N/A
Arsenic	Health-Based	N/A	0.0109	Dec 31, 2022	Resolved	Skin damage; circulatory system problems; increased risk of cancer
Revised Total Coliform Rule	Monitoring	N/A	N/A	Nov 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Nov 30, 2022	Resolved	N/A
TTHM	Health-Based	N/A	90.6	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Nitrate	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
TTHM	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	N/A
Total Haloacetic Acids (HAA5)	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	N/A
Nitrate	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Nitrate	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	Infants below the age of six months could become seriously ill (blue baby syndrome); shortness of breath
Lead and Copper Rule	Monitoring	N/A	N/A	Dec 31, 2021	Active	N/A
TTHM	Health-Based	N/A	83.8	Jun 30, 2021	Resolved	N/A
TTHM	Health-Based	N/A	83.8	Jun 30, 2021	Resolved	N/A

Lead & Copper Levels

Violation Timeline

2025(67)

Revised Total Coliform Rule

Jul 31Resolved

TTHM

Jun 30Resolved

Consumer Confidence Rule

Jun 30Resolved

Consumer Confidence Rule

Jun 30Resolved

BHC-GAMMA

Jun 30Resolved

Chlordane

Jun 30Resolved

Pentachlorophenol

Jun 30Resolved

Simazine

Jun 30Resolved

Vinyl chloride

Jun 30Resolved

1,2-Dichloroethane

Jun 30Resolved

Heptachlor epoxide

Jun 30Resolved

Heptachlor

Jun 30Resolved

Toluene

Jun 30Resolved

2,4,5-TP

Jun 30Resolved

1,1,2-Trichloroethane

Jun 30Resolved

Benzene

Jun 30Resolved

Carbon tetrachloride

Jun 30Resolved

CHLOROBENZENE

Jun 30Resolved

1,2-Dichloroethane

Jun 30Resolved

Styrene

Jun 30Resolved

Ethylbenzene

Jun 30Resolved

Styrene

Jun 30Resolved

1,2,4-Trichlorobenzene

Jun 30Resolved

Tetrachloroethylene

Jun 30Resolved

Picloram

Jun 30Resolved

1,1-Dichloroethylene

Jun 30Resolved

Dinoseb

Jun 30Resolved

CHLOROBENZENE

Jun 30Resolved

Trichloroethylene

Jun 30Resolved

o-Dichlorobenzene

Jun 30Resolved

1,2,4-Trichlorobenzene

Jun 30Resolved

DICHLOROMETHANE

Jun 30Resolved

o-Dichlorobenzene

Jun 30Resolved

1,1,2-Trichloroethane

Jun 30Resolved

trans-1,2-Dichloroethylene

Jun 30Resolved

Dalapon

Jun 30Resolved

Carbon tetrachloride

Jun 30Resolved

DICHLOROMETHANE

Jun 30Resolved

p-Dichlorobenzene

Jun 30Resolved

p-Dichlorobenzene

Jun 30Resolved

1,2-Dichloropropane

Jun 30Resolved

Endrin

Jun 30Resolved

cis-1,2-Dichloroethylene

Jun 30Resolved

1,2-Dichloropropane

Jun 30Resolved

Ethylbenzene

Jun 30Resolved

Benzene

Jun 30Resolved

Toluene

Jun 30Resolved

1,1-Dichloroethylene

Jun 30Resolved

1,1,1-Trichloroethane

Jun 30Resolved

Di(2-ethylhexyl) adipate

Jun 30Resolved

Trichloroethylene

Jun 30Resolved

Atrazine

Jun 30Resolved

Tetrachloroethylene

Jun 30Resolved

1,1,1-Trichloroethane

Jun 30Resolved

Vinyl chloride

Jun 30Resolved

trans-1,2-Dichloroethylene

Jun 30Resolved

Methoxychlor

Jun 30Resolved

Toxaphene

Jun 30Resolved

Di(2-ethylhexyl) phthalate

Jun 30Resolved

Hexachlorocyclopentadiene

Jun 30Resolved

LASSO

Jun 30Resolved

HEXACHLOROBENZENE

Jun 30Resolved

Benzo(a)pyrene

Jun 30Resolved

cis-1,2-Dichloroethylene

Jun 30Resolved

Consumer Confidence Rule

Jun 30Resolved

TTHM

Mar 31Resolved

Revised Total Coliform Rule

Jan 31Resolved

2024(22)

TTHM

Dec 31Resolved

TTHM

Dec 31Resolved

TTHM

Sep 30Resolved

TTHM

Sep 30Resolved

Revised Total Coliform Rule

Sep 30Resolved

Revised Total Coliform Rule

Aug 31Resolved

Revised Total Coliform Rule

Jul 31Resolved

Revised Total Coliform Rule

Jul 31Resolved

Revised Total Coliform Rule

Jul 31Resolved

TTHM

Jun 30Resolved

TTHM

Jun 30Resolved

Total Haloacetic Acids (HAA5)

Jun 30Resolved

Consumer Confidence Rule

Jun 30Resolved

TTHM

Jun 30Resolved

Consumer Confidence Rule

Jun 30Resolved

Revised Total Coliform Rule

Apr 30Resolved

Total Haloacetic Acids (HAA5)

Mar 31Resolved

TTHM

Mar 31Resolved

TTHM

Mar 31Resolved

TTHM

Mar 31Resolved

Arsenic

Mar 31Resolved

Revised Total Coliform Rule

Feb 29Resolved

How Does This Compare?

Oak Harbor (98277) has 147 recorded violations, including 26 health-based. 1 remains unresolved. Consider testing your tap water independently for added peace of mind.

Recommended Water Filters

Based on the contaminants detected in your area, these filter types may help improve your water quality.

Reverse Osmosis System

Highly effective at removing heavy metals, dissolved solids, and a wide range of contaminants. Recommended for homes with lead or arsenic concerns.

Targets:Lead, Copper, Arsenic, Mercury, Cadmium

Look for:NSF/ANSI 58 certified

NSF Certified Products → EPA Safe Drinking Water Guide →

Activated Carbon Filter

Excellent for removing chlorine, chloramine, and disinfection byproducts like THMs and HAAs. Available as pitcher filters, countertop, or under-sink units.

Targets:THMs, HAAs, Chlorine, Chloramine, Taste & Odor

Look for:NSF/ANSI 42 & 53 certified

NSF Certified Products → EPA Safe Drinking Water Guide →

UV Water Purifier

Uses ultraviolet light to neutralize bacteria, viruses, and parasites without chemicals. Ideal for homes with microbial contamination concerns.

Targets:E. coli, Coliform, Giardia, Cryptosporidium

Look for:NSF/ANSI 55 (Class A) certified

NSF Certified Products → EPA Safe Drinking Water Guide →

Always look for filters certified by NSF International for the specific contaminants you want to remove.

Water Quality in Oak Harbor, WA (98277)

What does this mean?

Violations Detail (147 total)

Lead & Copper Levels

Violation Timeline

2025(67)

2024(22)

2023(19)

2022(24)

2021(15)

How Does This Compare?

Recommended Water Filters

Reverse Osmosis System

Activated Carbon Filter

UV Water Purifier

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