Cerro Gordo County, Iowa
10 ZIP codes · Avg score 62/100 · Grade C · Updated 2026-06-04
Within Cerro Gordo County, safety data across 10 ZIP codes suggests a fair but uneven system — violations are present and worth checking at the ZIP level.
How Cerro Gordo County Compares
How Cerro Gordo County Compares
Cerro Gordo County scores 3 points above the Iowa state average (59/100) and 6 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-04
ZIP Code Risk Map
Water Quality Map: Cerro Gordo County, Iowa
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%, diabetes 12.5%)
Estimated additional annual cost per homeowner: $1,093, driven primarily by flood
Infrastructure: 0.49% avg pipe failure probability, 80% of ZIPs at high risk
87.3% of homes built before 1978 (lead paint era)
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: $1,093
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
22,363 housing units in Cerro Gordo 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 Cerro Gordo County
Remediation costs are relatively manageable for most homeowners in Cerro Gordo 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 Cerro Gordo 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 Cerro Gordo County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Plymouth Water Supply | 378 | 6 |
| 2 | Mason City Water Department | 27,338 | 2 |
| 3 | Clear Lake Water Department | 7,687 | 2 |
| 4 | Ventura Water Works | 716 | 1 |
| 5 | Rockwell Water Supply | 1,071 | 1 |
10 total water systems serve Cerro Gordo County.
All ZIP Codes in Cerro Gordo County
10 ZIP codes tracked in Cerro Gordo County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 50428 | Clear Lake | 70 | B | 0 | $254K |
| 2 | 50479 | Thornton | 70 | B | 0 | $112K |
| 3 | 50402 | Mason City | 66 | C | 1 | — |
| 4 | 50457 | Meservey | 66 | C | 0 | $94K |
| 5 | 50482 | Ventura | 66 | C | 1 | $221K |
| 6 | 50477 | Swaledale | 65 | C | 0 | $75K |
| 7 | 50469 | Rockwell | 64 | C | 1 | $189K |
| 8 | 50464 | Plymouth | 61 | C | 6 | $167K |
| 9 | 50401 | Mason City | 55 | C | 1 | $134K |
| 10 | 50467 | Rock Falls | 40 | D | 0 | $160K |
Recommended Buyer Guides for Cerro Gordo County
Designed to find the guide that fits the county, not the other way around — the system reads EPA detections, FEMA hazard layers, and CDC lead-exposure markers, then outputs the categories that resolve those specific risks for households here, with NSF-certified products surfaced when the matching contaminant appears in the local monitoring data.
- Best Lead Paint Test Kits — 87.3% of homes built before 1978
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
- 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 Cerro Gordo County, Iowa
Overview
Cerro Gordo County in Iowa covers 10 ZIP codes with an average Home Safety Score of C (62/100).
5 of 10 ZIP codes have recorded EPA violations. All violations are monitoring/reporting type.
← Back to Iowa 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.