Water Quality in Oak Harbor, OH: 1 Violation — Grade C
Grade C · Score 60/100 · 1 water system · Updated 2026-05-03
Oak Harbor's water has moderate compliance issues. Residents in affected areas should consider filtration.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
Reviewing EPA compliance files for Oak Harbor, OH surfaces 1 documented water violation — each categorized by violation type and linked to the utility that drew the federal citation.
Water Quality by ZIP Code in Oak Harbor
Water quality varies across Oak Harbor's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 43449 | C | 60 | 1 | 0 | View report → |
Water Quality Overview
Oak Harbor, Ohio receives a water quality grade of C with an overall score of 60 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 1 water system serving Oak Harbor have accumulated 1 EPA violations (all monitoring/reporting type). These violations are tracked across 1 ZIP codes serving approximately 4,615 people.
What Grade C Means
A grade of C indicates moderate compliance issues. Oak Harbor's water systems have some violations that warrant attention. While the water may still be safe for most people, residents in affected ZIP codes should consider additional testing or filtration.
Lead Levels
Lead testing data for Oak Harbor is currently being collected. The EPA requires all community water systems to test for lead under the Lead and Copper Rule.
With 67% 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.
Radon Risk
Oak Harbor is in EPA Radon Zone 2 (Moderate risk). Testing is recommended, especially for homes with basements or ground-level living spaces.
Water Systems Serving Oak Harbor
Oak Harbor is served by 1 community water system regulated under the Safe Drinking Water Act. These systems collectively serve approximately 4,615 people across 1 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 8 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, violation history, and safety scores
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 |
|---|---|---|---|---|---|
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 1 | 1 | No |
MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.
EPA Enforcement History
The EPA and state regulators have taken 8 enforcement actions against water systems serving Oak Harbor. Recent actions:
| Date | Action Type |
|---|---|
| 2025-06-05 | State Informal Action |
| 2025-05-13 | State Informal Action |
| 2025-05-13 | State Informal Enforcement |
| 2025-04-11 | State Order Extension |
| 2023-06-30 | State Order Extension |
| 2022-11-21 | State Informal Action |
| 2022-10-21 | State Informal Action |
| 2022-10-21 | State Informal Enforcement |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-06-05.
Oak Harbor vs. Nearby Ohio Cities
How Oak Harbor's water quality compares to similar cities in Ohio:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Oak Harbor | C | 1 | 1 | 4,615 |
| Lacarne | D | 0 | 1 | 4,615 |
| Rocky Ridge | D | 0 | 1 | 4,615 |
| Crestline | C | 1 | 1 | 4,630 |
Common Questions About Oak Harbor Water
These are the most common questions residents search for about water quality in Oak Harbor, Ohio:
Is Oak Harbor water hard or soft? Water hardness varies by source. Oak Harbor's 1 water system uses a single source. Check your ZIP code report for specific hardness data.
Can I drink Oak Harbor tap water? Oak Harbor's water receives a grade of C (60/100). No health-based violations have been recorded, but home testing is always recommended.
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. Ohio Average
Understanding how Oak Harbor compares to the broader Ohio 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 1 ZIP code. The ZIP with the lowest water quality score is 43449. Each ZIP code has its own water quality profile based on the specific water system serving that area. 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
Updated daily.