Clay County, Iowa
7 ZIP codes · Avg score 55/100 · Grade C · Updated 2026-06-03
Safe water is the norm for most of Clay County's 7 ZIP codes — but a notable subset have documented violations that push the grade to the middle tier.
How Clay County Compares
How Clay County Compares
Clay County scores 4 points below the Iowa state average (59/100) and 13 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Clay County, Iowa
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 13.7 (asthma 9.9%, diabetes 12.3%)
Estimated additional annual cost per homeowner: $981, driven primarily by energy_code_gap
Infrastructure: 0.489% avg pipe failure probability, 100% of ZIPs at high risk
85% 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: $981
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
7,421 housing units in Clay 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 Clay County
Remediation costs are relatively manageable for most homeowners in Clay 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 Clay 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 Clay County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Everly Water Supply | 575 | 1 |
| 2 | Peterson Municipal Water Supply | 322 | 0 |
| 3 | Spencer Municipal Water Utility | 11,325 | 0 |
| 4 | Iowa Lakes Regional Water - Osgood | 8,500 | 0 |
| 5 | Iowa Lakes Regional Water | 6,755 | 0 |
7 total water systems serve Clay County.
All ZIP Codes in Clay County
7 ZIP codes tracked in Clay County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 51338 | Everly | 70 | B | 1 | $120K |
| 2 | 51047 | Peterson | 66 | C | 0 | $131K |
| 3 | 51340 | Fostoria | 66 | C | 0 | $117K |
| 4 | 51301 | Spencer | 60 | C | 0 | $180K |
| 5 | 51341 | Gillett Grove | 40 | D | 0 | $63K |
| 6 | 51343 | Greenville | 40 | D | 0 | $112K |
| 7 | 51357 | Royal | 40 | D | 0 | $121K |
Recommended Buyer Guides for Clay County
Retailer arrangements don't shape what appears here — the selection logic is independent, filtered against EPA detections and the federal hazard data on file for this county.
- Best Lead Paint Test Kits — 85% of homes built before 1978
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
Deep Dive Reports
Detailed analysis for Clay County, Iowa
Overview
Clay County in Iowa covers 7 ZIP codes with an average Home Safety Score of C (55/100).
1 of 7 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.