COUNTY REPORT MN

Washington County, Minnesota

20 ZIP codes · Avg score 55/100 · Grade C · Updated 2026-06-03

Safe water is the norm for most of Washington County's 20 ZIP codes — but a notable subset have documented violations that push the grade to the middle tier.

How Washington County Compares

Washington County55/100
Minnesota avg62/100
National avg68/100

How Washington County Compares

C
County Grade
55/100
Avg Safety Score
20
ZIP Codes
22
Water Systems

Washington County scores 7 points below the Minnesota state average (62/100) and 13 points below the national average (68/100).

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

C
County Grade
55
Avg Safety Score
20
ZIP Codes
Best ZIP: 55016 (70/100)
Lowest ZIP: 55146 (40/100)
$362K
Median Home Value
$2,320
Avg Remediation (64% of home value)

ZIP Code Risk Map

Water Quality Map: Washington 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: 11.1 (asthma 9.5%, diabetes 10.3%)

Estimated additional annual cost per homeowner: $1,402, driven primarily by flood

Infrastructure: 0.353% avg pipe failure probability, 26% of ZIPs at high risk

58.3% of homes built before 1978 (lead paint era)

Violation History (2023–2025)

→ Stable trend

EPA violation counts by year across Washington County water systems. Health-based shown in red, total in blue.

2023
2 (2 health)
2024
5 (5 health)
2025
8 (8 health)

Peak year: 2025 with 8 violations. Past 5 years: 15 total (15 health-based).

Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.

County Health Indicators vs National Average

Asthma 9.5% (national: 8.9%)
Diabetes 10.3% (national: 10.5%)
Obesity 32.5% (national: 32.4%)

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

Infrastructure Overview

1982
Median Build Year
58.3%
Pre-1978 Housing
35%
Pipe Failure Probability
26%
ZIPs at High Infra Risk
Moderate
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: $1,402

Flood $820/yr
Energy Code Gap $342/yr
Water / Lead $128/yr

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

Housing Age Distribution

142,326 housing units in Washington County

Pre-1940 10%
1940–1959 12%
1960–1979 23%
1980–1999 33%
2000+ 22%

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

$362K
Median Home Value
$2,320
Est. Remediation Cost
0.6%
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 9.5% (US avg: 8.9%)
Diabetes 10.3% (US avg: 11%)
Obesity 32.5% (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 Washington County ranked by EPA violation count.

# Water System Population Violations
1 Wyoming 3,990 12
2 Preserve at Birch Lake 388 12
3 Scandia Water Company 35 11
4 Hilltop Water Company 25 11
5 Woodlund Mobile Home Park 330 5

22 total water systems serve Washington County.

All ZIP Codes in Washington County

20 ZIP codes tracked in Washington County.

# ZIP Code City Safety Score Grade Violations Home Value
1 55016 Cottage Grove 70 B 1 $359K
2 55025 Forest Lake 70 B 1 $386K
3 55055 Newport 65 C 0 $331K
4 55083 Stillwater 65 C 2
5 55082 Stillwater 64 C 2 $460K
6 55042 Lake Elmo 63 C 1 $594K
7 55043 Lakeland 60 C 1 $361K
8 55073 Scandia 60 C 11 $470K
9 55075 South Saint Paul 53 D 0 $267K
10 55090 Willernie 53 D 1 $305K
11 55115 Saint Paul 53 D 0 $482K
12 55119 Saint Paul 53 D 0 $263K
13 55125 Saint Paul 53 D 0 $397K
14 55128 Saint Paul 53 D 0 $301K
15 55003 Bayport 52 D 1 $363K
16 55001 Afton 45 D 0 $654K
17 55107 Saint Paul 45 D 0 $260K
18 55110 Saint Paul 45 D 0 $347K
19 55129 Saint Paul 40 D 0 $518K
20 55146 Saint Paul 40 D 0

Recommended Buyer Guides for Washington County

Editorial methodology pairs each documented risk in this county with the buyer category that addresses it, drawing on water-quality detections, housing-stock lead exposure, EPA Radon Zone designation, and FEMA flood and wildfire ratings. NSF-certified options surface where applicable, and products that match the specific contaminant take priority.

Overview

Washington County in Minnesota covers 20 ZIP codes with an average Home Safety Score of C (55/100).

9 of 20 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 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 22 public water systems that supply drinking water to residents across 20 ZIP codes.
What is the biggest environmental risk in Washington County?
The primary environmental risk factor in Washington County is flood. This contributes to an estimated additional annual cost of $1,402 per homeowner.
How old are homes in Washington County?
The median home build year in Washington County is 1982. 58.3% of homes were built before 1978, which means they may contain lead-based paint and older plumbing materials.
How does Washington County compare to Minnesota?
Washington County has an average water safety score of 55/100, which is below the Minnesota state average of 62/100.

Get safety alerts for Washington, Minnesota

Free updates when EPA data changes for this area. No spam.

Unsubscribe anytime. Privacy Policy.

Share This Page

X Facebook
Check your water filter options Free tool — no phone call required.