Is Twin Lakes, WI Tap Water Safe to Drink?
Graded F — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
44/100
waterverge.com Twin Lakes, WI — Water Quality Report
Twin Lakes's drinking water received a grade of F (44 out of 100), indicating failing water quality. The city's 11 water systems serve approximately 905 residents using groundwater.
Lead levels were measured at 5.7 ppb (90th percentile), which is within EPA limits but above recommended levels. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 958 violations on record, including 29 health-based violations. 130 remain unresolved.
What to know about Twin Lakes's water
Twin Lakes ranks #431 out of 446 cities in Wisconsin for water quality, placing it among the lowest-rated in the state.
Twin Lakes 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.
While lead levels are within EPA limits, they are above the recommended 5 ppb threshold that health organizations consider ideal. A point-of-use filter adds an extra layer of protection.
As a small community water system, Twin Lakes may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
The system has seen 24 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Twin Lakes, WI water safe to drink?
Twin Lakes's drinking water has significant quality concerns based on EPA testing data. With a grade of F (44/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 11 water systems serve approximately 905 residents using groundwater (wells).
Recent water quality updates for Twin Lakes
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Twin Lakes's water quality assessment. Grade: F (44/100).
Federal disaster declaration (FEMA DR-4892). Flood event — may have impacted local water infrastructure.
Contaminants: Revised Total Coliform Rule.
Contaminants: LEAD AND COPPER RULE REVISIONS.
Contaminants: Lead and Copper Rule, Revised Total Coliform Rule.
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 Twin Lakes's water supply.
Within EPA limits but above the American Academy of Pediatrics recommended level of 1 ppb. An NSF 53-certified filter provides additional protection.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
Violation history
Twin Lakes's water system has 958 total violations on record, including 29 health-based violations. 130 remain unresolved. 24 violations were issued in the last 5 years.
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, Little Menomonee River, Underwood Creek, Honey Creek, Root River.
Where does Twin Lakes's water come from?
Twin Lakes's drinking water comes from groundwater (wells), supplied by 11 water systems serving approximately 905 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), Little Menomonee River (river), Underwood Creek (river), Honey Creek (river), Root River (river).
What Twin Lakes residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Twin Lakes's water.
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.
Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.
Twin Lakes'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.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Top industrial polluters within 10 miles of Twin Lakes
Industrial polluters nearby
Reported releases to surface water by facilities near Twin Lakes, ranked by pounds discharged annually.
Total reported releases to surface water: 9 lbs
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
SCOT FORGE CO SPRING GROVE, IL60081 | Nickel | 9 | 5.0 mi |
APPLIED MATERIAL SOLUTIONS BURLINGTON, WI53105 | — | — | 9.4 mi |
QUAD/GRAPHICS COMMERCIAL & SPECIALTY LLC BURLINGTON, WI53105 | — | — | 8.9 mi |
R&L SPRING CO LAKE GENEVA, WI53147 | — | — | 9.3 mi |
STELLANA US LAKE GENEVA, WI53147 | — | — | 9.7 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Superfund sites within 10 miles of Twin Lakes
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.
- H O D LANDFILL9.0 mi
Source: EPA Superfund National Priorities List
Flood & disaster history
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.
Recommended water filters
Based on contaminants detected in Twin Lakes's water supply, we recommend the following filter types.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 5.7 | 15 | ppb | Inorganic | Safe |
| Copper (90th percentile) CopperInorganic A metal that enters drinking water mainly through corrosion of copper plumbing. Small amounts are essential for health, but excess levels are harmful. Health EffectsGastrointestinal distress (nausea, vomiting, diarrhea) at short-term high levels; liver and kidney damage from long-term exposure. EPA Limit1.3 mg/L action level Common SourcesCorrosion of copper household plumbing, erosion of natural deposits. | 1.50 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how Twin Lakes compares by contaminant
Explore where Twin Lakes ranks among all Wisconsin cities for specific contaminants.
Water source & infrastructure
Where Twin Lakes's water comes from
Twin Lakes'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 private ownership and serves approximately 905 people through 11 water systems.
Water bodies near Twin Lakes
Twin Lakes is located near 5 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Twin Lakes
| System Name | PWSID | Population | Source |
|---|---|---|---|
| TAN OAK APTS | WI2301080 | 325 | GW |
| TWIN LAKES PARK WATER COOP | WI2300151 | 150 | GW |
| LAKEWOOD VILLAGE APTS | WI2300940 | 125 | GW |
| WYWOOD COMMUNITY INC | WI2300152 | 59 | GW |
| TWIN LAKES COMPLEX | WI2300619 | 50 | GW |
| MEADOWVIEW VILLAGE APTS | WI2300172 | 48 | GW |
| LINCOLN CREST APARTMENTS | WI2301743 | 32 | GW |
| HOLY HILL APARTMENTS | WI2300140 | 32 | GW |
| 337-9 HOLY HILL APARTMENTS LLC | WI2300159 | 30 | GW |
| 425 HOLY HILL APTS | WI2300163 | 28 | GW |
| RESIDENCES ON MAIN | WI2302061 | 26 | GW |
How Twin Lakes compares
Full Wisconsin rankings →Twin Lakes's score of 44/100 is below the average of 65/100 among major Wisconsin cities. It outscores 1 of 10 nearby cities. 9 of 10 nearby cities score higher.
Nearby cities
View Wisconsin rankings →About Twin Lakes, WI
Wikipedia →Brookfield is a city in eastern Waukesha County, Wisconsin, United States. It had a population of 41,464 at the 2020 census. The city is adjacent to the Town of Brookfield and is part of the Milwaukee metropolitan area.
Learn more about your water
Guides and resources related to Twin Lakes's water quality findings.
Explore water quality across Kenosha
Frequently asked questions
Is Twin Lakes, WI tap water safe to drink?
Twin Lakes's water quality earned a grade of F (44/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #431 out of 446 cities tested in Wisconsin.
What contaminants are in Twin Lakes's water?
Lead was measured at 5.7 ppb (90th percentile). 958 violations are on record.
How is Twin Lakes'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 Twin Lakes?
While lead levels are within EPA limits, a filter adds extra protection. Based on current data, basic filtration should suffice for additional peace of mind.
Where does Twin Lakes's water come from?
Twin Lakes's water is sourced from Groundwater. The city has 11 water systems serving approximately 905 residents.
What health violations has Twin Lakes's water system had?
Twin Lakes has 29 health-based violations on record. The most recent violation was recorded in September 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 130 violations remain unresolved.
Is Twin Lakes's groundwater at risk of contamination?
Twin Lakes 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 958 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 Twin Lakes's water compare to other cities?
Twin Lakes ranks #431 out of 446 cities in Wisconsin (better than 3% of state cities) and #14489 out of 15744 cities nationally (8th percentile). The grade of F reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.