Story County, Iowa
18 ZIP codes · Avg score 64/100 · Grade C · Updated 2026-06-04
Safe water is the norm for most of Story County's 18 ZIP codes — but a notable subset have documented violations that push the grade to the middle tier.
How Story County Compares
How Story County Compares
Story County scores 5 points above the Iowa state average (59/100) and 4 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-04
ZIP Code Risk Map
Water Quality Map: Story County, Iowa
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 10.2 (asthma 9.7%, diabetes 8.1%)
Estimated additional annual cost per homeowner: $870, driven primarily by flood
Infrastructure: 0.411% avg pipe failure probability, 67% of ZIPs at high risk
65.8% of homes built before 1978 (lead paint era)
Violation History (2022–2025)
→ Stable trendEPA violation counts by year across Story County water systems. Health-based shown in red, total in blue.
Peak year: 2023 with 10 violations. Past 5 years: 14 total (14 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: $870
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
42,497 housing units in Story 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 Story County
Remediation costs are relatively manageable for most homeowners in Story 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 Story 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 Story County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Ames Water Treatment Plant | 55,177 | 10 |
| 2 | ISU | 42,000 | 10 |
| 3 | Logansport Water System | 190 | 10 |
| 4 | Maple Grove Mhc | 160 | 10 |
| 5 | Squaw Valley South Subdivision | 105 | 10 |
27 total water systems serve Story County.
All ZIP Codes in Story County
18 ZIP codes tracked in Story County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 50046 | Cambridge | 70 | B | 0 | $225K |
| 2 | 50055 | Collins | 70 | B | 0 | $195K |
| 3 | 50105 | Gilbert | 70 | B | 1 | $265K |
| 4 | 50236 | Roland | 70 | B | 0 | $186K |
| 5 | 50011 | Ames | 68 | C | 2 | — |
| 6 | 50014 | Ames | 68 | C | 2 | $313K |
| 7 | 50248 | Story City | 68 | C | 2 | $219K |
| 8 | 50124 | Huxley | 66 | C | 0 | $300K |
| 9 | 50134 | Kelley | 66 | C | 0 | $278K |
| 10 | 50278 | Zearing | 65 | C | 3 | $170K |
| 11 | 50012 | Ames | 64 | C | 2 | — |
| 12 | 50013 | Ames | 64 | C | 2 | — |
| 13 | 50056 | Colo | 64 | C | 1 | $184K |
| 14 | 50161 | Maxwell | 64 | C | 2 | $205K |
| 15 | 50244 | Slater | 64 | C | 2 (1 health) | $236K |
| 16 | 50010 | Ames | 58 | C | 2 | $243K |
| 17 | 50201 | Nevada | 57 | C | 0 | $187K |
| 18 | 50154 | Mc Callsburg | 40 | D | 0 | $174K |
Recommended Buyer Guides for Story County
Eight risk categories drive the selection — PFAS exceedance, lead above EPA action level, pre-1978 housing share, EPA Radon Zone 1, flood-top-risk, wildfire-top-risk, multi-contaminant load, and a baseline fallback — and each category maps to a specific buyer-guide track that surfaces when the county data hits its threshold for that hazard signal.
- Best Lead Paint Test Kits — 65.8% 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 Story County, Iowa
Overview
Story County in Iowa covers 18 ZIP codes with an average Home Safety Score of C (64/100).
11 of 18 ZIP codes have recorded EPA violations. 1 health-based violation have been documented.
← 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.