Water Quality in Oak Harbor, WA: 152 Violations - Grade N/A
5 water systems · 2 directly mapped ZIP records
Available EPA records report 152 violations across 2 directly mapped ZIP records with known counts for Oak Harbor. This is compliance evidence, not a property-level tap-water verdict.
Data: EPA Safe Drinking Water Information System (SDWIS)
Water Quality by ZIP Code in Oak Harbor
This table shows typed EPA water evidence only. Missing violation counts are displayed as N/A, not zero.
| ZIP Code | Violations | Health | |
|---|---|---|---|
| 98277 | 152 | 41 | View report → |
| 98278 | 0 | 0 | View report → |
Violation Trend
EPA violations recorded for water systems serving Oak Harbor.
| Year | Total violations | Health-based |
|---|---|---|
| 2021 | 1 | 1 |
| 2022 | 1 | 1 |
| 2023 | 4 | 4 |
| 2024 | 4 | 4 |
| 2025 | 4 | 4 |
| 2026 | 1 | 1 |
Water Quality Overview
Oak Harbor, Washington has directly mapped EPA water-system data for 2 ZIP codes. This page reports typed compliance facts and does not relabel the multi-source Home Safety Score as a drinking-water grade.
The available EPA records report 152 violations, including 41 health-based violations across 2 directly mapped ZIP records with reported counts.
Lead Levels
The average 90th percentile lead level across Oak Harbor water systems is 0.0262 mg/L - this exceeds the EPA action level of 0.015 mg/L. 1 ZIP code exceed the EPA lead action level.
With 49% of homes built before 1986, Oak Harbor has a higher-than-average risk of lead from older plumbing. Lead solder was banned in 1986, and homes built before this date may have lead in pipes, solder joints, or fixtures.
Water Systems Serving Oak Harbor
Oak Harbor is served by 5 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 42,516 people across 2 ZIP codes.
Each water system is identified by a Public Water System ID (PWSID) and is required to:
- Test for over 90 regulated contaminants on a regular schedule
- Report results to the EPA and state regulators
- Issue an annual Consumer Confidence Report (CCR) to all customers
- Take corrective action when violations occur
The EPA has taken 10 enforcement actions against water systems serving Oak Harbor. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Oak Harbor
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels and violation history
Request your CCR - your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants
Get a home test - certified kits cost $20–$50 and test for lead, bacteria, and common contaminants. Professional lab tests ($150–$400) cover a broader panel
Consider filtration - NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics
Check for advisories - monitor your local utility website and local news for boil water advisories or system alerts
Contaminants Detected in Oak Harbor Water Systems
The following contaminants have been detected or caused violations across Oak Harbor's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 0.06 mg/L | 54 | 1 | Yes |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 27 | 1 | Yes |
| Surface Water Treatment Rule | Treatment Technique | N/A | 15 | 1 | No |
| Lead | Inorganic | 0.015 mg/L | 14 | 1 | No |
| Stage 1 DBP Rule | Treatment Technique | N/A | 4 | 1 | Yes |
| PFOA | PFAS | 0.000004 mg/L | 1 | 1 | No |
| PFNA | PFAS | 0.00001 mg/L | 1 | 1 | No |
| Dichloroacetic Acid | Disinfection Byproducts | 0.06 mg/L | 1 | 1 | No |
| Bromodichloromethane | Disinfection Byproducts | 0.08 mg/L | 1 | 1 | No |
| Dibromochloromethane | Disinfection Byproducts | 0.08 mg/L | 1 | 1 | No |
| Bromoform | Disinfection Byproducts | 0.08 mg/L | 1 | 1 | No |
| Chlorodibromomethane | Disinfection Byproducts | 0.08 mg/L | 1 | 1 | No |
| Trichloroacetic Acid | Disinfection Byproducts | 0.06 mg/L | 1 | 1 | No |
| Monobromoacetic Acid | Disinfection Byproducts | 0.06 mg/L | 1 | 1 | No |
| Dibromoacetic Acid | Disinfection Byproducts | 0.06 mg/L | 1 | 1 | No |
MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.
Violation Trend Over Time
Year-by-year EPA violations recorded for water systems serving Oak Harbor:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2021 | 1 | 1 |
| 2022 | 1 | 1 |
| 2023 | 4 | 4 |
| 2024 | 4 | 4 |
| 2025 | 4 | 4 |
| 2026 | 1 | 1 |
Violation counts have remained stable over the observed period.
EPA Enforcement History
The EPA and state regulators have taken 9 enforcement actions against water systems serving Oak Harbor. Recent actions:
| Date | Action Type |
|---|---|
| 2025-10-08 | State Order Extension |
| 2024-06-27 | State Order Extension |
| 2023-12-18 | State Order Extension |
| 2023-01-02 | State Order Extension |
| 2022-10-05 | State Order Extension |
| 2021-12-31 | State Order Extension |
| 2021-07-07 | State Order Extension |
| 2021-03-29 | State Order Extension |
| 2021-03-24 | State Order Extension |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-10-08.
Oak Harbor vs. Nearby Washington Cities
How Oak Harbor's water quality compares to similar cities in Washington:
| City | Direct EPA ZIPs | Violations | Systems | Population |
|---|---|---|---|---|
| Oak Harbor | 2 | 152 | 5 | 42,516 |
| Walla Walla | 1 | 119 | 5 | 42,794 |
| Lacey | 1 | 5 | 3 | 42,189 |
| Wenatchee | 1 | 2 | 3 | 44,422 |
Common Questions About Oak Harbor Water
These are the most common questions residents search for about water quality in Oak Harbor, Washington:
Is Oak Harbor water hard or soft? Water hardness varies by source. Oak Harbor's 5 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Oak Harbor tap water? City-level EPA records cannot determine safety at a specific tap. The measured subset contains 41 health-based violations; check the affected utility record and consider certified testing.
What is the best water filter for Oak Harbor? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Oak Harbor vs. Washington Average
Understanding how Oak Harbor compares to the broader Washington average helps contextualize your local water quality. Factors like water source, treatment methods, and infrastructure age all contribute to differences between cities in the same state.
To see how individual neighborhoods compare, check the ZIP code reports below - water quality can vary significantly even within Oak Harbor.
ZIP Codes in Oak Harbor
Oak Harbor spans 2 ZIP codes. EPA water-system coverage is available for 2 directly mapped ZIP codes. Check each ZIP code for detailed contaminant data, violation history, and system information.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
- Enforcement: EPA ECHO database
- Filter recommendations: NSF/ANSI certified products
Source reporting periods vary. See each cited source for its publication schedule.