COUNTY REPORT MN

Rock County, Minnesota

8 ZIP codes · Avg score 59/100 · Grade C · Updated 2026-06-03

Within Rock County, 8 tracked ZIP codes reveal moderate water quality — national standards are generally met, with some documented exceptions.

How Rock County Compares

Rock County59/100
Minnesota avg62/100
National avg68/100

How Rock County Compares

C
County Grade
59/100
Avg Safety Score
8
ZIP Codes
9
Water Systems

Rock County scores 3 points below the Minnesota state average (62/100) and 9 points below the national average (68/100).

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

C
County Grade
59
Avg Safety Score
8
ZIP Codes
Best ZIP: 56116 (66/100)
Lowest ZIP: 56146 (40/100)
$198K
Median Home Value
$1,350
Avg Remediation (68% of home value)

ZIP Code Risk Map

Water Quality Map: Rock County, Minnesota

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: 13.2 (asthma 10%, diabetes 11.4%)

Estimated additional annual cost per homeowner: $1,195, driven primarily by energy_code_gap

Infrastructure: 0.464% avg pipe failure probability, 100% of ZIPs at high risk

80.8% of homes built before 1978 (lead paint era)

County Health Indicators vs National Average

Asthma 10% (national: 8.9%)
Diabetes 11.4% (national: 10.5%)
Obesity 36.6% (national: 32.4%)

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

Infrastructure Overview

1950
Median Build Year
80.8%
Pre-1978 Housing
46%
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: $1,195

Energy Code Gap $540/yr
Water / Lead $400/yr
Flood $175/yr

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

Housing Age Distribution

4,014 housing units in Rock County

Pre-1940 30%
1940–1959 22%
1960–1979 25%
1980–1999 13%
2000+ 10%

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 Rock County

$198K
Median Home Value
$1,350
Est. Remediation Cost
0.7%
of Home Value
Remediation as % of home value low burden

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

Asthma 10% (US avg: 8.9%)
Diabetes 11.4% (US avg: 11%)
Obesity 36.6% (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 Rock County ranked by EPA violation count.

# Water System Population Violations
1 Rock County Rural Water System 2,919 4
2 Steen 180 3
3 Hardwick 198 1
4 Beaver Creek 297 0
5 Hills 685 0

9 total water systems serve Rock County.

All ZIP Codes in Rock County

8 ZIP codes tracked in Rock County.

# ZIP Code City Safety Score Grade Violations Home Value
1 56116 Beaver Creek 66 C 0 $220K
2 56134 Hardwick 66 C 1 $198K
3 56138 Hills 66 C 0 $198K
4 56147 Kenneth 66 C 0 $120K
5 56156 Luverne 65 C 0 $201K
6 56158 Magnolia 55 C 0 $109K
7 56173 Steen 51 D 3 $166K
8 56146 Kanaranzi 40 D 0

Recommended Buyer Guides for Rock County

Strictly editorial — no paid placements influence which guides appear; the selection draws on NSF certifications and EPA detection records for water systems serving this county.

Overview

Rock County in Minnesota covers 8 ZIP codes with an average Home Safety Score of C (59/100).

2 of 8 ZIP codes have recorded EPA violations. All violations are monitoring/reporting type.

← Back to Minnesota water quality report

Data Sources

Updated daily.

Frequently Asked Questions

Is water safe in Rock County?
Rock 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 Rock County?
Rock County is served by 9 public water systems that supply drinking water to residents across 8 ZIP codes.
What is the biggest environmental risk in Rock County?
The primary environmental risk factor in Rock County is energy_code_gap. This contributes to an estimated additional annual cost of $1,195 per homeowner.
How old are homes in Rock County?
The median home build year in Rock County is 1950. 80.8% of homes were built before 1978, which means they may contain lead-based paint and older plumbing materials.
How does Rock County compare to Minnesota?
Rock County has an average water safety score of 59/100, which is below the Minnesota state average of 62/100.

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