Delaware County, Iowa
6 ZIP codes · Avg score 65/100 · Grade C · Updated 2026-06-03
For most households in Delaware County, the 6 tracked ZIP codes show adequate but uneven water quality.
How Delaware County Compares
How Delaware County Compares
Delaware County scores 6 points above the Iowa state average (59/100) and 3 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Delaware County, Iowa
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 14.4 (asthma 9.9%, diabetes 12.5%)
Estimated additional annual cost per homeowner: $845, driven primarily by flood
Infrastructure: 0.46% avg pipe failure probability, 83% of ZIPs at high risk
70.2% 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: $845
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
6,392 housing units in Delaware 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 Delaware County
Remediation costs are relatively manageable for most homeowners in Delaware 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 Delaware 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 Delaware County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Delhi Water Supply | 420 | 2 |
| 2 | Penn Center Inc. | 89 | 2 |
| 3 | Ryan Water Supply | 350 | 2 |
| 4 | Delaware Municipal Water Supply | 142 | 0 |
| 5 | Earlville Muni Water Supply | 724 | 0 |
7 total water systems serve Delaware County.
All ZIP Codes in Delaware County
6 ZIP codes tracked in Delaware County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 52223 | Delhi | 69 | C | 2 | $195K |
| 2 | 52036 | Delaware | 66 | C | 0 | $140K |
| 3 | 52041 | Earlville | 66 | C | 0 | $212K |
| 4 | 52237 | Hopkinton | 66 | C | 0 | $135K |
| 5 | 52330 | Ryan | 61 | C | 2 | $164K |
| 6 | 52057 | Manchester | 60 | C | 0 | $169K |
Recommended Buyer Guides for Delaware County
Filtered against federal data, fitted to local risks.
- Best Lead Paint Test Kits — 70.2% 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 Delaware County, Iowa
Overview
Delaware County in Iowa covers 6 ZIP codes with an average Home Safety Score of C (65/100).
2 of 6 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.