WaterVerge

Is Sussex, WI Tap Water Safe to Drink?

Graded D+ — but Manganese was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓

12K residents served 2 water systems PWSID: WI2680233
Overall Score
53.2 / 100
Violations
21 active
Last Updated
May 2026
Source
Groundwater
#402 of 446 in Wisconsin Top 81% nationally
Local Government
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
D+GRADE
Water Quality Grade
53.2/100
waterverge.com
D+ 53.2/100

Sussex, WI — Water Quality Report

Sussex's drinking water received a grade of D+ (53.2 out of 100), indicating poor water quality. The city's 2 water systems serve approximately 12,196 residents using groundwater.

Lead levels were measured at 0.9 ppb (90th percentile), well within EPA limits. PFAS testing under UCMR 5 found no detectable forever chemicals.

The system has 323 violations on record, including 70 health-based violations. 21 remain unresolved.

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

What to know about Sussex's water

Sussex ranks #402 out of 446 cities in Wisconsin for water quality, placing it among the lowest-rated in the state.

Sussex 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.

Quality Breakdown

Water quality score

See methodology →
53.2 out of 100 Grade D+
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
3/45
F
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 0.9 ppb (90th percentile).
Contaminants
17.2/20
B
No PFAS compounds detected.
Compliance
8/10
B
Monitoring and reporting compliance with EPA regulations.
Source Risk
5/5
A
Water source: Groundwater.
Water Safety

Is Sussex, WI water safe to drink?

Concerns Identified

Sussex's drinking water has significant quality concerns based on EPA testing data. With a grade of D+ (53.2/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 12,196 residents using groundwater (wells).

21
Active Violations
0.9 ppb
Lead (90th %ile)
None
PFAS Detected
7 events
Disaster History

Recent water quality updates for Sussex

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

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Sussex's water quality assessment. Grade: D+ (53.2/100).

Disaster
SEVERE STORMS, STRAIGHT-LINE WINDS, FLOODING, AND MUDSLIDES

Federal disaster declaration (FEMA DR-4892). Flood event — may have impacted local water infrastructure.

Violation
1 drinking water violation recorded

Contaminants: Lead and Copper Rule.

Violation
1 drinking water violation recorded

Contaminants: Revised Total Coliform Rule.

Violation
1 drinking water violation recorded

Contaminants: Lead and Copper Rule.

Disaster
HURRICANE KATRINA EVACUATION

Federal disaster declaration (FEMA DR-3249). Hurricane event — may have impacted local water infrastructure.

Key contaminant findings

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

Lead Within Limits
Detected: 0.9 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

Violation history

Sussex's water system has 323 total violations on record, including 70 health-based violations. 21 remain unresolved. 3 violations were issued in the last 5 years.

MRMONMCLOther
Most recent violations:
Jun 2023 Lead and Copper Rule Open
Sep 2021 Revised Total Coliform Rule Resolved
Feb 2021 Lead and Copper Rule Open
Oct 2019 Radium-228 Resolved
Oct 2019 Radium-226 Resolved

Flood & environmental risk

Waukesha County has experienced 7 federally declared disasters since 1969. 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 Menomonee River, Fox River.

SEVERE STORMS, STRAIGHT-LINE WINDS, FLOODING, AND MUDSLIDES
Flood FEMA DR-4892
HURRICANE KATRINA EVACUATION
Hurricane FEMA DR-3249
SEVERE STORMS & FLOODING
Flood FEMA DR-775

Where does Sussex's water come from?

Sussex's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 12,196 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Menomonee River (river), Fox River (river).

What Sussex residents can do

Install a water filter

Recommended: NSF-certified water filter. This addresses the specific contaminants found in Sussex's water.

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

Sussex'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
0.9 ppb
EPA Action Level: 15 ppb · 6% of limit
Safe Level
HAA5 (Disinfection Byproducts)
Disinfection Byproduct
Safe
1.5 µg/L
EPA MCL: 60 µg/L · 3% of limit
Within LimitUCMR 4 DataHAA6Br: 1.6 µg/LHAA9: 2.8 µg/L
Manganese
Inorganic
Over SMCL
160.5 µg/L
EPA Secondary MCL: 50 µg/L · +20% over limit
Over SMCLUCMR 4 Data
PFAS Testing

Forever chemicals overview

National PFAS report →
30
Compounds tested
0
Detected
0
Exceed EPA MCL
Compliance Record

Violation summary

323
Total violations
70
Health-based
21
Active / unresolved
Jun 2023
Most recent violation
Compliance Record

Violations & advisories

323 Total
21 Active
70 Health-based
302 Resolved
Violations by category
Synthetic Organic Chemicals
110
Volatile Organic Chemicals
106
Radionuclides and Revised Rad Rule
70
Public Notice Rule and Revised PN Rule
13
Total Coliform Rule
11
Jun 2023 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Feb 2021 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Dec 2018 Active
Public Notice
Other Violation 0
Dec 2017 Active
Public Notice
Other Violation 0
Dec 2017 Active
Public Notice
Other Violation 0
Dec 2017 Active
Public Notice
Other Violation 0
Sep 2017 Active
Public Notice
Other Violation 0
Sep 2016 Active
Public Notice
Other Violation 0
Sep 2016 Active
Public Notice
Other Violation 0
Jun 2016 Active
Public Notice
Other Violation 0
Dec 2015 Active
Public Notice
Other Violation 0
Apr 2014 Active
Public Notice
Other Violation 0
Oct 2013 Active
Consumer Confidence Rule
Other Violation 0
Aug 2013 Active
Public Notice
Other Violation 0
Jun 2013 Active
Public Notice
Other Violation 0
Jan 2012 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Jul 2008 Active
Consumer Confidence Rule
Other Violation 0
Mar 2008 Active
Public Notice
Other Violation 0
Jul 2003 Active
Consumer Confidence Rule
Other Violation 0
Active
Compliance Violation
Monitoring 0
Showing 20 of 323 violations
Industrial pollution

Top industrial polluters within 10 miles of Sussex

Industrial polluters nearby

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

Total reported releases to surface water: 88 lbs

FacilityTop chemicalTo surface water (lbs/yr)Distance
METALTEK INTERNATIONAL-WISCO NSIN CENTRIFUGAL DIV
Primary Metals · METALTEK INTERNATIONAL
WAUKESHA, WI53188
Copper647.9 mi
NORTHERN STAINLESS CORP
Primary Metals · NA
PEWAUKEE, WI53072
Copper154.0 mi
WAUKESHA FOUNDRY INC
Primary Metals · UNITED STARS INC
WAUKESHA, WI53186
Copper compounds98.7 mi
FLINT HILLS RESOURCES PINE BEND LLC MILWAUKEE TERMINAL
Petroleum Bulk Terminals · KOCH INC
MILWAUKEE, WI53224
Polycyclic aromatic compounds09.9 mi
CHEMSTATION OF WISCONSIN
Chemicals · CHEMSTATION INTERNATIONAL INC
BUTLER, WI53007
7.8 mi

Source: EPA Toxic Release Inventory (TRI) 2023

Site context

Superfund sites within 10 miles of Sussex

Superfund sites nearby

Federally tracked hazardous-waste sites on the EPA National Priorities List. Proximity does not necessarily indicate tap-water contamination — the connection depends on hydrology and treatment.

Source: EPA Superfund National Priorities List

Environmental Risk

Flood & disaster history

7
Declared disasters
Sep 2025
Most recent
Flood
Most common type

Waukesha County has experienced 7 federally declared disasters since 1969. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

Sep 2025
SEVERE STORMS, STRAIGHT-LINE WINDS, FLOODING, AND MUDSLIDES
Flood FEMA #4892
Sep 2005
HURRICANE KATRINA EVACUATION
Hurricane FEMA #3249
Oct 1986
SEVERE STORMS & FLOODING
Flood FEMA #775
Aug 1986
SEVERE STORMS
Flood FEMA #770
Mar 1976
SEVERE STORMS, ICING, WIND & FLOODING
Flood FEMA #496
Apr 1973
SEVERE STORMS & FLOODING
Flood FEMA #376

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 0.9 15 ppb Inorganic Safe
11Cl-PF3OUdS ND HI µg/L PFAS Not Detected
4:2 FTS ND HI µg/L PFAS Not Detected
6:2 FTS ND HI µg/L PFAS Not Detected
8:2 FTS ND HI µg/L PFAS Not Detected
9Cl-PF3ONS ND HI µg/L PFAS Not Detected
ADONA ND HI µg/L PFAS Not Detected
HFPO-DA ND 0.01 µg/L PFAS Not Detected
lithium ND HI µg/L PFAS Not Detected
NEtFOSAA ND HI µg/L PFAS Not Detected
NFDHA ND HI µg/L PFAS Not Detected
NMeFOSAA ND HI µg/L PFAS Not Detected
PFBA ND HI µg/L PFAS Not Detected
PFBS ND HI µg/L PFAS Not Detected
PFDA ND HI µg/L PFAS Not Detected
PFDoA ND HI µg/L PFAS Not Detected
PFEESA ND HI µg/L PFAS Not Detected
PFHpA ND HI µg/L PFAS Not Detected
PFHpS ND HI µg/L PFAS Not Detected
PFHxA ND HI µg/L PFAS Not Detected
PFHxS ND HI µg/L PFAS Not Detected
PFMBA ND HI µg/L PFAS Not Detected
PFMPA ND HI µg/L PFAS Not Detected
PFNA ND HI µg/L PFAS Not Detected
PFOA ND 0.004 µg/L PFAS Not Detected
PFOS ND 0.004 µg/L PFAS Not Detected
PFPeA ND HI µg/L PFAS Not Detected
PFPeS ND HI µg/L PFAS Not Detected
PFTA ND HI µg/L PFAS Not Detected
PFTrDA ND HI µg/L PFAS Not Detected
PFUnA ND HI µg/L PFAS Not Detected
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has decreased by 9.2 ppb from 1992 (12.0 ppb) to 2024 (2.8 ppb).
Infrastructure

Water source & infrastructure

Primary Source
Groundwater
Operator
Local Government
Population Served
12,196
Water Systems
2
Water Source

Where Sussex's water comes from

Groundwater

Sussex'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 12,196 people through 2 water systems.

Local Hydrology

Water bodies near Sussex

Sussex is located near 2 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.

Menomonee River
river
Fox River
river
Infrastructure

Water systems serving Sussex

System Name PWSID Population Source
SUSSEX VILLAGE HALL & WATER UTILITY WI2680233 11,750 GW
WILLOW SPRINGS MHP 2 & 3 WI2680232 446 GW
Regional Comparison

How Sussex compares

Full Wisconsin rankings →

Sussex's score of 53.2/100 is below the average of 65/100 among major Wisconsin cities. It outscores 4 of 10 nearby cities. 6 of 10 nearby cities score higher.

Sussex (this city)
53.2
Milwaukee
90.2
Madison
35.4
Racine
69.5
Kenosha
45.8
Wisconsin avg
65
City Profile

About Sussex, WI

Wikipedia →

Sussex is a village in Waukesha County, Wisconsin, United States, about 19 miles (31 km) northwest of Milwaukee and 9 miles (14 km) north of Waukesha. The village is 7.24 square miles (19 km2) at an elevation of 930 feet. The population was 11,487 at the 2020 census. It is part of the Milwaukee metropolitan area.

Economic Profile
$105,435
Median Income
$359,717
Median Home Value
$1,222/mo
Median Rent
3.6%
Unemployment
Community
38.3
Median Age
550
People / sq mi
47.7%
College Educated
68.4%
Homeownership
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Frequently asked questions

Is Sussex, WI tap water safe to drink?

Sussex's water quality earned a grade of D+ (53.2/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #402 out of 446 cities tested in Wisconsin.

What contaminants are in Sussex's water?

Lead was measured at 0.9 ppb (90th percentile). No PFAS compounds were detected. 323 violations are on record.

How is Sussex'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 Sussex?

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

Where does Sussex's water come from?

Sussex's water is sourced from Groundwater. The city has 2 water systems serving approximately 12,196 residents.

What health violations has Sussex's water system had?

Sussex has 70 health-based violations on record. The most recent violation was recorded in June 2023. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 21 violations remain unresolved.

Is Sussex's groundwater at risk of contamination?

Sussex 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 323 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 Sussex's water compare to other cities?

Sussex ranks #402 out of 446 cities in Wisconsin (better than 10% of state cities) and #12704 out of 15744 cities nationally (19th percentile). The grade of D+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.