COUNTY REPORT IA

Hamilton County, Iowa

9 ZIP codes · Avg score 57/100 · Grade C · Updated 2026-06-03

Compared to top-scoring counties, Hamilton County's 9 ZIP codes land in the middle tier — some meet standards cleanly, others carry documented violations, and the gap between the best and worst areas is wider than average.

How Hamilton County Compares

Hamilton County57/100
Iowa avg59/100
National avg68/100

How Hamilton County Compares

C
County Grade
57/100
Avg Safety Score
9
ZIP Codes
11
Water Systems

Hamilton County scores 2 points below the Iowa state average (59/100) and 11 points below the national average (68/100).

Data: EPA SDWIS Last verified: 2026-06-03

C
County Grade
57
Avg Safety Score
9
ZIP Codes
Best ZIP: 50034 (66/100)
Lowest ZIP: 50132 (40/100)
$120K
Median Home Value
$1,333
Avg Remediation (111% of home value)

ZIP Code Risk Map

Water Quality Map: Hamilton County, Iowa

Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.

A B C D F

Key Risk Factors

Health risk index: 13.5 (asthma 9.8%, diabetes 12.1%)

Estimated additional annual cost per homeowner: $958, driven primarily by water_lead

Infrastructure: 0.53% avg pipe failure probability, 100% of ZIPs at high risk

84% of homes built before 1978 (lead paint era)

County Health Indicators vs National Average

Asthma 9.8% (national: 8.9%)
Diabetes 12.1% (national: 10.5%)
Obesity 36.5% (national: 32.4%)

Black markers indicate national averages. Source: CDC PLACES, Census ACS.

Infrastructure Overview

1949
Median Build Year
84%
Pre-1978 Housing
53%
Pipe Failure Probability
100%
ZIPs at High Infra Risk
High
Lead Pipe Risk

Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.

Compound Risk Breakdown

Estimated additional annual cost per homeowner: $958

Water / Lead $472/yr
Energy Code Gap $330/yr
Flood $156/yr

Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).

Housing Age Distribution

7,135 housing units in Hamilton County

Pre-1940 39%
1940–1959 16%
1960–1979 23%
1980–1999 15%
2000+ 6%

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 Hamilton County

$120K
Median Home Value
$1,333
Est. Remediation Cost
1.1%
of Home Value
Remediation as % of home value low burden

Remediation costs are relatively manageable for most homeowners in Hamilton 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 Hamilton County residents

Asthma 9.8% (US avg: 8.9%)
Diabetes 12.1% (US avg: 11%)
Obesity 36.5% (US avg: 32.4%)

Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.

Water Systems with Most Violations

Top 5 systems in Hamilton County ranked by EPA violation count.

# Water System Population Violations
1 Xenia Rwd (des Moines) 12,860 11
2 Xenia Rwd (boone) 4,975 4
3 Xenia Rwd (north) 6,122 4
4 Stratford Muni Water Department 707 4
5 Stanhope Water Department 364 3

11 total water systems serve Hamilton County.

All ZIP Codes in Hamilton County

9 ZIP codes tracked in Hamilton County.

# ZIP Code City Safety Score Grade Violations Home Value
1 50034 Blairsburg 66 C 0 $113K
2 50231 Randall 66 C 0 $106K
3 50271 Williams 66 C 1 $138K
4 50595 Webster City 65 C 0 $129K
5 50075 Ellsworth 64 C 2 $140K
6 50249 Stratford 59 C 4 $109K
7 50130 Jewell 48 D 1 $143K
8 50246 Stanhope 42 D 3 $118K
9 50132 Kamrar 40 D 0 $120K

Recommended Buyer Guides for Hamilton County

Federal and certification sources drive the ordering: EPA monitoring data, NSF certifications, FEMA flood maps, and CDC lead guidance — guides surface only when county data warrants them.

Overview

Hamilton County in Iowa covers 9 ZIP codes with an average Home Safety Score of C (57/100).

5 of 9 ZIP codes have recorded EPA violations. All violations are monitoring/reporting type.

← Back to Iowa water quality report

Data Sources

Updated daily.

Frequently Asked Questions

Is water safe in Hamilton County?
Hamilton County receives a grade of C. Some ZIP codes have recorded violations and residents in affected areas may want to test their water.
How many water systems serve Hamilton County?
Hamilton County is served by 11 public water systems that supply drinking water to residents across 9 ZIP codes.
What is the biggest environmental risk in Hamilton County?
The primary environmental risk factor in Hamilton County is water_lead. This contributes to an estimated additional annual cost of $958 per homeowner.
How old are homes in Hamilton County?
The median home build year in Hamilton County is 1949. 84% of homes were built before 1978, which means they may contain lead-based paint and older plumbing materials.
How does Hamilton County compare to Iowa?
Hamilton County has an average water safety score of 57/100, which is below the Iowa state average of 59/100.

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