Mahaska County, Iowa
7 ZIP codes · Avg score 52/100 · Grade D · Updated 2026-06-03
Poor compliance rates put Mahaska County in the bottom safety tier — 7 ZIP codes, below the state average.
How Mahaska County Compares
How Mahaska County Compares
Mahaska County scores 7 points below the Iowa state average (59/100) and 16 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Mahaska County, Iowa
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 13.8 (asthma 10.1%, diabetes 11.7%)
Estimated additional annual cost per homeowner: $790, driven primarily by energy_code_gap
Infrastructure: 0.461% avg pipe failure probability, 71% of ZIPs at high risk
76.9% 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: $790
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
8,898 housing units in Mahaska 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 Mahaska County
Remediation costs are relatively manageable for most homeowners in Mahaska 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 Mahaska 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 Mahaska County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Mahaska Rural Water (new Sharon) | 1,368 | 5 |
| 2 | OSKALOOSA MUNICIPAL WATER DEPT | 12,808 | 4 |
| 3 | Mahaska Rural Water System, Inc. | 9,818 | 4 |
| 4 | Bussey Water Supply | 427 | 4 |
| 5 | Oak Creek Mhp | 165 | 4 |
7 total water systems serve Mahaska County.
All ZIP Codes in Mahaska County
7 ZIP codes tracked in Mahaska County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 52577 | Oskaloosa | 68 | C | 4 | $144K |
| 2 | 50207 | New Sharon | 66 | C | 1 | $157K |
| 3 | 50027 | Barnes City | 54 | D | 2 | $100K |
| 4 | 52553 | Eddyville | 53 | D | 0 | $144K |
| 5 | 52534 | Beacon | 40 | D | 0 | $74K |
| 6 | 52543 | Cedar | 40 | D | 0 | $107K |
| 7 | 52595 | University Park | 40 | D | 0 | $89K |
Recommended Buyer Guides for Mahaska County
Below: editorial picks, no sponsored placements.
- Best Lead Paint Test Kits — 76.9% of homes built before 1978
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
Deep Dive Reports
Detailed analysis for Mahaska County, Iowa
Overview
Mahaska County in Iowa covers 7 ZIP codes with an average Home Safety Score of D (52/100).
3 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.
What You Can Do
Mahaska County has a grade of D. Here are steps to protect your household.
Test your tap water
Order a certified lab test kit ($20-$50) to check for lead, bacteria, and other contaminants specific to your ZIP code.
Consider a certified water filter
NSF-certified filters can remove most common contaminants. Match the filter to your test results for best protection. Try our filter matcher
Contact your water utility
Request the latest Consumer Confidence Report (CCR) from your water provider. It details exactly what was found in your water supply.
Check for lead in your home
76.9% of homes in this county were built before 1978. Older plumbing and solder can leach lead into drinking water, especially in the morning.