Ottawa County, Ohio
12 ZIP codes · Avg score 59/100 · Grade C · Updated 2026-06-03
Water systems across Ottawa County's 12 ZIP codes produce average compliance results overall — pockets with documented violations exist, and the variation between areas makes ZIP-level lookup the most useful tool for residents here.
How Ottawa County Compares
How Ottawa County Compares
Ottawa County scores 1 points below the Ohio state average (60/100) and 9 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Ottawa County, Ohio
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 14.3 (asthma 10.6%, diabetes 13.3%)
Estimated additional annual cost per homeowner: $1,901, driven primarily by flood
Infrastructure: 0.439% avg pipe failure probability, 73% of ZIPs at high risk
77.1% of homes built before 1978 (lead paint era)
Violation History (2022–2024)
→ Stable trendEPA violation counts by year across Ottawa County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 9 violations. Past 5 years: 10 total (10 health-based).
Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $1,901
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
19,106 housing units in Ottawa County
Source: U.S. Census Bureau ACS B25034 (Year Structure Built).
Water Safety Affordability
How much it costs to fix water issues relative to home values in Ottawa County
Remediation costs are relatively manageable for most homeowners in Ottawa County, representing a small fraction of property value.
Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.
Health Outcomes vs National Average
CDC PLACES data for Ottawa County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 5 systems in Ottawa County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | GENOA VILLAGE | 3,110 | 3 |
| 2 | Woodville Village | 2,006 | 3 |
| 3 | Green Valley Mobile Home Park | 82 | 3 |
| 4 | OTTAWA COUNTY REGIONAL WATER DISTRICT | 20,428 | 1 |
| 5 | OAK HARBOR VILLAGE | 4,615 | 1 |
10 total water systems serve Ottawa County.
All ZIP Codes in Ottawa County
12 ZIP codes tracked in Ottawa County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 43416 | Elmore | 71 | B | 3 (1 health) | $176K |
| 2 | 43452 | Port Clinton | 68 | C | 0 | $207K |
| 3 | 43432 | Graytown | 63 | C | 0 | $216K |
| 4 | 43445 | Martin | 63 | C | 0 | $191K |
| 5 | 43468 | Williston | 63 | C | 0 | $210K |
| 6 | 43449 | Oak Harbor | 60 | C | 1 | $175K |
| 7 | 43447 | Millbury | 55 | C | 0 | $208K |
| 8 | 43408 | Clay Center | 53 | D | 0 | $121K |
| 9 | 43433 | Gypsum | 53 | D | 0 | — |
| 10 | 43439 | Lacarne | 53 | D | 0 | — |
| 11 | 43441 | Lemoyne | 53 | D | 0 | — |
| 12 | 43458 | Rocky Ridge | 53 | D | 0 | $88K |
Recommended Buyer Guides for Ottawa County
While many sites publish identical guide lists across every county they cover, the selection here changes by location — driven by the EPA, NSF, FEMA, and CDC datasets that describe the actual conditions documented for this jurisdiction in the federal record.
- Best Lead Paint Test Kits — 77.1% of homes built before 1978
- Best Sump Pumps — Flood is the top compound risk factor
- Best Mold Test Kits — Flood-driven moisture and mold risk
Deep Dive Reports
Detailed analysis for Ottawa County, Ohio
Overview
Ottawa County in Ohio covers 12 ZIP codes with an average Home Safety Score of C (59/100).
2 of 12 ZIP codes have recorded EPA violations. 1 health-based violation have been documented.
← Back to Ohio water quality report
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Updated daily.