WaterVerge

Is Wonewoc, WI Tap Water Safe to Drink?

Graded A, with 2 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓

758 residents served 1 water system PWSID: WI7290137
Overall Score
91.4 / 100
Violations
2 active
Last Updated
May 2026
Source
Groundwater
#54 of 446 in Wisconsin Top 11% nationally
Local Government
Moderate data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
AGRADE
Water Quality Grade
91.4/100
waterverge.com
A 91.4/100

Wonewoc, WI — Water Quality Report

Wonewoc's drinking water received a grade of A (91.4 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 758 residents using groundwater.

Lead levels were measured at 1.6 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.

The system has 5 violations on record, including 1 health-based violation. 2 remain unresolved.

Data last updated: May 2026 · Source: EPA SDWIS, UCMR 5
Analysis

What to know about Wonewoc's water

Wonewoc ranks #54 out of 446 cities in Wisconsin for water quality, placing it above average in the state.

Wonewoc relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.

As a small community water system, Wonewoc may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.

Quality Breakdown

Water quality score

See methodology →
91.4 out of 100 Grade A
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
44.4/45
A
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 1.6 ppb (90th percentile).
Contaminants
17/20
B
PFAS + legacy contaminant analysis.
Compliance
5/10
D
Monitoring and reporting compliance with EPA regulations.
Source Risk
5/5
A
Water source: Groundwater.
Water Safety

Is Wonewoc, WI water safe to drink?

Use Caution

Wonewoc's tap water meets most EPA standards but has areas that warrant attention. With a grade of A (91.4/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 758 residents using groundwater (wells).

2
Active Violations
1.6 ppb
Lead (90th %ile)
5 events
Disaster History

Recent water quality updates for Wonewoc

A timeline of significant water quality events, violations, and data updates.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Wonewoc's water quality assessment. Grade: A (91.4/100).

Disaster
SEVERE STORMS, TORNADOES, STRAIGHT-LINE WINDS, FLOODING, AND LANDSLIDES

Federal disaster declaration (FEMA DR-4402). Flood event — may have impacted local water infrastructure.

Disaster
SEVERE STORMS, FLOODING, AND MUDSLIDES

Federal disaster declaration (FEMA DR-4288). Flood event — may have impacted local water infrastructure.

Violation
2 drinking water violations recorded

Contaminants: Chlorine, Coliform (TCR).

Violation
1 drinking water violation recorded

Contaminants: Lead and Copper Rule.

Violation
1 drinking water violation recorded

1 health-based. Contaminants: Coliform (TCR).

Key contaminant findings

Based on the most recent EPA sampling data for Wonewoc's water supply.

Lead Within Limits
Detected: 1.6 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

Violation history

Wonewoc's water system has 5 total violations on record, including 1 health-based violation. 2 remain unresolved.

MRMCL
Most recent violations:
Jul 2015 Chlorine Resolved
Jul 2015 Coliform (TCR) Resolved
Jan 2012 Lead and Copper Rule Open
Mar 1995 Coliform (TCR) Resolved

Flood & environmental risk

Juneau County has experienced 5 federally declared disasters since 1992. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Baraboo River.

SEVERE STORMS, TORNADOES, STRAIGHT-LINE WINDS, FLOODING, AND LANDSLIDES
Flood FEMA DR-4402
SEVERE STORMS, FLOODING, AND MUDSLIDES
Flood FEMA DR-4288
HURRICANE KATRINA EVACUATION
Hurricane FEMA DR-3249

Where does Wonewoc's water come from?

Wonewoc's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 758 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Baraboo River (river).

What Wonewoc residents can do

Request your utility's CCR

Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.

Monitor alerts during storms

Wonewoc's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.

Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.

Contaminant Alerts

Top contaminants to know

View all ↓
Lead (90th percentile)
Inorganic / Heavy Metal
Safe
1.6 ppb
EPA Action Level: 15 ppb · 11% of limit
Safe Level
Compliance Record

Violation summary

5
Total violations
1
Health-based
2
Active / unresolved
Jul 2015
Most recent violation
Compliance Record

Violations & advisories

5 Total
2 Active
1 Health-based
3 Resolved
Violations by category
Total Coliform Rule
2
Stage 1 Disinfectants and Disinfection Byproducts Rule
1
Lead and Copper Rule
1
Jan 2012 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Active
Compliance Violation
Monitoring 0
Jul 2015 Resolved
Chlorine
Monitoring & Reporting
Monitoring & Reporting Resolved Sep 2015
Jul 2015 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Jul 2015
Mar 1995 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Mar 1995
Industrial pollution

Top industrial polluters within 10 miles of Wonewoc

Industrial polluters nearby

Reported releases to surface water by facilities near Wonewoc, ranked by pounds discharged annually.

FacilityTop chemicalTo surface water (lbs/yr)Distance
SPRINKMAN MANUFACTURING
Machinery · KRONES INC
ELROY, WI53929
7.0 mi
WABASH (WALKER STAINLESS EQUIPMENT CO)
Fabricated Metals · WABASH NATIONAL CORP
ELROY, WI53929
6.7 mi
LAND O'LAKES INC. - HILLSBORO
Food · LAND O LAKES INC
HILLSBORO, WI54634
5.7 mi

Source: EPA Toxic Release Inventory (TRI) 2023

Environmental Risk

Flood & disaster history

5
Declared disasters
Oct 2018
Most recent
Flood
Most common type

Juneau County has experienced 5 federally declared disasters since 1992. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

Oct 2018
SEVERE STORMS, TORNADOES, STRAIGHT-LINE WINDS, FLOODING, AND LANDSLIDES
Flood FEMA #4402
Oct 2016
SEVERE STORMS, FLOODING, AND MUDSLIDES
Flood FEMA #4288
Sep 2005
HURRICANE KATRINA EVACUATION
Hurricane FEMA #3249
May 2001
FLOODING, SEVERE STORMS AND TORNADOES
Flood FEMA #1369
Sep 1992
SEVERE STORMS & FLOODING
Flood FEMA #964

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 1.6 15 ppb Inorganic Safe
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has decreased by 11.4 ppb from 1993 (13.0 ppb) to 2023 (1.6 ppb).
Infrastructure

Water source & infrastructure

Primary Source
Groundwater
Operator
Local Government
Population Served
758
Water Systems
1
Water Source

Where Wonewoc's water comes from

Groundwater

Wonewoc's drinking water is drawn from underground aquifers through wells.

Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.

Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.

The system is operated by local government ownership and serves approximately 758 people through 1 water system.

Local Hydrology

Water bodies near Wonewoc

Wonewoc is located near 1 notable water body. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.

Baraboo River
river
Infrastructure

Water systems serving Wonewoc

System Name PWSID Population Source
WONEWOC WATERWORKS WI7290137 758 GW
Regional Comparison

How Wonewoc compares

Full Wisconsin rankings →

Wonewoc's score of 91.4/100 is above the average of 65/100 among major Wisconsin cities. It outscores 9 of 10 nearby cities.

Wonewoc (this city)
91.4
Milwaukee
90.2
Madison
35.4
Racine
69.5
Kenosha
45.8
Wisconsin avg
65
City Profile

About Wonewoc, WI

Economic Profile
$63,819
Median Income
$96,356
Median Home Value
$820/mo
Median Rent
3.2%
Unemployment
Community
35.5
Median Age
244
People / sq mi
19.5%
College Educated
77.5%
Homeownership
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Frequently asked questions

Is Wonewoc, WI tap water safe to drink?

Wonewoc's water quality earned a grade of A (91.4/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #54 out of 446 cities tested in Wisconsin.

What contaminants are in Wonewoc's water?

Lead was measured at 1.6 ppb (90th percentile). 5 violations are on record.

How is Wonewoc's water quality grade calculated?

The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.

Do I need a water filter in Wonewoc?

Based on current data, basic filtration should suffice for additional peace of mind.

Where does Wonewoc's water come from?

Wonewoc's water is sourced from Groundwater. The city has 1 water system serving approximately 758 residents.

What health violations has Wonewoc's water system had?

Wonewoc has 1 health-based violation on record. The most recent violation was recorded in July 2015. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 2 violations remain unresolved.

Is Wonewoc's groundwater at risk of contamination?

Wonewoc uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 5 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.

How does Wonewoc's water compare to other cities?

Wonewoc ranks #54 out of 446 cities in Wisconsin (better than 88% of state cities) and #1732 out of 15744 cities nationally (89th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.

Does Wonewoc's small water system affect quality?

Wonewoc's system serves approximately 758 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 5 violations on record.