COUNTY REPORT IA

Washington County, Iowa

7 ZIP codes · Avg score 65/100 · Grade C · Updated 2026-06-03

Water systems across Washington County's 7 ZIP codes produce average compliance results overall — pockets with documented violations exist, and the variation between areas makes ZIP-level lookup the most useful tool for residents here.

How Washington County Compares

Washington County65/100
Iowa avg59/100
National avg68/100

How Washington County Compares

C
County Grade
65/100
Avg Safety Score
7
ZIP Codes
20
Water Systems

Washington 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

C
County Grade
65
Avg Safety Score
7
ZIP Codes
Best ZIP: 52201 (70/100)
Lowest ZIP: 52621 (55/100)
$182K
Median Home Value
$2,243
Avg Remediation (123% of home value)

ZIP Code Risk Map

Water Quality Map: Washington 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: 13.8 (asthma 9.8%, diabetes 12%)

Estimated additional annual cost per homeowner: $737, driven primarily by energy_code_gap

Infrastructure: 0.49% avg pipe failure probability, 100% of ZIPs at high risk

73.3% of homes built before 1978 (lead paint era)

County Health Indicators vs National Average

Asthma 9.8% (national: 8.9%)
Diabetes 12% (national: 10.5%)
Obesity 38.6% (national: 32.4%)

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

Infrastructure Overview

1957
Median Build Year
73.3%
Pre-1978 Housing
49%
Pipe Failure Probability
100%
ZIPs at High Infra Risk
Low
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: $737

Energy Code Gap $309/yr
Water / Lead $257/yr
Flood $171/yr

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

Housing Age Distribution

9,607 housing units in Washington County

Pre-1940 39%
1940–1959 11%
1960–1979 19%
1980–1999 16%
2000+ 15%

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 Washington County

$182K
Median Home Value
$2,243
Est. Remediation Cost
1.2%
of Home Value
Remediation as % of home value low burden

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

Asthma 9.8% (US avg: 8.9%)
Diabetes 12% (US avg: 11%)
Obesity 38.6% (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 Washington County ranked by EPA violation count.

# Water System Population Violations
1 Kalona Water Department 2,630 3
2 Riverside Water Supply 1,060 3
3 Iowa City Water Department 68,753 2
4 Lake Ridge, Incorporated 1,300 2
5 Hills Water Supply 863 2

20 total water systems serve Washington County.

All ZIP Codes in Washington County

7 ZIP codes tracked in Washington County.

# ZIP Code City Safety Score Grade Violations Home Value
1 52201 Ainsworth 70 B 1 $182K
2 52353 Washington 70 B 0 $156K
3 52247 Kalona 68 C 1 $257K
4 52327 Riverside 65 C 2 $288K
5 52359 West Chester 64 C 1 $163K
6 52356 Wellman 62 C 0 $205K
7 52621 Crawfordsville 55 C 0 $105K

Recommended Buyer Guides for Washington County

Methodologically, the recommendation order reflects severity in the federal record: contaminants flagged in EPA detection records for this county outrank generic water concerns, FEMA-confirmed hazard ratings shift emergency-related categories upward, and CDC lead-exposure markers govern when lead-test kits and certified filters appear at the top of the list.

Overview

Washington County in Iowa covers 7 ZIP codes with an average Home Safety Score of C (65/100).

4 of 7 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 Washington County?
Washington 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 Washington County?
Washington County is served by 20 public water systems that supply drinking water to residents across 7 ZIP codes.
What is the biggest environmental risk in Washington County?
The primary environmental risk factor in Washington County is energy_code_gap. This contributes to an estimated additional annual cost of $737 per homeowner.
How old are homes in Washington County?
The median home build year in Washington County is 1957. 73.3% of homes were built before 1978, which means they may contain lead-based paint and older plumbing materials.
How does Washington County compare to Iowa?
Washington County has an average water safety score of 65/100, which is above the Iowa state average of 59/100.

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