Milwaukee – Wisconsin
Milwaukee Water Works (MWW), established in 1871, serves approximately 867,000 residents across Milwaukee and 15 surrounding communities. The utility manages over 2,000 miles of water mains, two water treatment plants, and numerous pumping stations, delivering roughly 100 million gallons daily from Lake Michigan, one of the world’s largest freshwater sources.
Milwaukee draws its drinking water exclusively from Lake Michigan, sourcing through two intake pipes extending up to two miles into the lake to access the cleanest, coldest deep water. After a devastating Cryptosporidium outbreak in 1993 that affected over 400,000 residents, Milwaukee transformed its water treatment system, becoming a national leader in water quality monitoring and advanced treatment technologies. Today, the city’s comprehensive monitoring program tests for over 500 contaminants—far exceeding the EPA’s required 91—and employs multiple treatment barriers to ensure exceptional water quality. Milwaukee’s approach to water management reflects the city’s historical commitment to environmental stewardship of the Great Lakes while embracing cutting-edge science and technology.
Milwaukee Water Quality: Current Status (2024-2025)
Latest Testing Results
- Lead Levels: The most recent testing period (January-December 2023) showed 90th percentile lead levels of 7.4 parts per billion (ppb), below the EPA action level of 15 ppb, reflecting effective corrosion control despite the city’s many lead service lines.
- Testing Scope: Milwaukee Water Works conducts over 200,000 water quality tests annually, monitoring for more than 500 contaminants—far exceeding the EPA-required 91 parameters.
- Compliance Status: Milwaukee’s water meets or exceeds all federal and state drinking water standards, maintaining full compliance with EPA and Wisconsin Department of Natural Resources regulations.
Lake Michigan Excellence
- Premium Source Water: Lake Michigan provides an abundant, relatively stable water source with excellent baseline quality compared to river systems, though seasonal algae and turbidity fluctuations do occur.
- Strategic Intake Design: Dual intake structures extend up to two miles offshore at depths of 40-65 feet to access the coldest, cleanest deep lake water, minimizing shoreline contaminants and seasonal temperature variations.
- Watershed Protection: Comprehensive source water protection programs coordinate with multiple state and local agencies across the Lake Michigan watershed to monitor and reduce potential contamination sources.
Multi-Barrier Treatment Approach
- Ozone Disinfection: Primary disinfection using ozone since 1998, one of the first major utilities to implement this technology following the 1993 Cryptosporidium outbreak, providing superior protection against resistant pathogens.
- Biologically Active Filtration: Advanced filtration process that removes particles while beneficial microorganisms break down remaining organic compounds, improving water taste and reducing disinfection byproducts.
- Continuous Monitoring: State-of-the-art real-time water quality monitoring throughout the treatment process and distribution system, with automated alerts for any variations from established parameters.
Lead Service Line Challenges
- Infrastructure Reality: Approximately 70,000 lead service lines remain in the Milwaukee water system, primarily in homes built before 1951. These represent a significant infrastructure challenge despite effective corrosion control treatment.
- Replacement Program: Milwaukee’s Lead Service Line Replacement Program prioritizes schools, childcare facilities, and properties with elevated lead levels, replacing approximately 1,000 lines annually with a goal to increase this rate through expanded funding.
- Corrosion Control Optimization: Advanced water chemistry management using orthophosphate treatment to create a protective coating inside pipes, minimizing lead leaching while comprehensive replacement programs continue.
Innovation Leadership
Milwaukee has transformed a historical water crisis into a platform for innovation, becoming home to The Water Council, a globally recognized hub for water technology research and development. The city has leveraged partnerships between utilities, universities, and private industry to advance water quality monitoring, emerging contaminant research, and infrastructure management technologies. This collaborative approach has positioned Milwaukee as a “Water Centric City” that balances tradition and innovation in urban water management, turning lessons from its past into opportunities for a sustainable water future. Milwaukee’s water expertise now supports water quality improvement initiatives across the Great Lakes region and beyond.
Recommendations for Milwaukee Residents
Check Your Service Line
Use Milwaukee’s online service line lookup tool at city.milwaukee.gov/water/WaterQuality/LeadandWater to see if your property has a lead service line. Properties built before 1951 are most likely to have lead connections.
Get Free Filters
Milwaukee provides free NSF-certified water filters for residents with lead service lines, pregnant women, and families with children under 6. Call (414) 286-2830 or visit the city’s lead-safe resource centers.
Test Your Water
Request free water testing through Milwaukee Water Works by calling (414) 286-2585. Priority testing is available for homes with children, pregnant women, or known lead service lines.
Flush Your Pipes
If water hasn’t been used for 6+ hours, run cold water for 3 minutes or until it feels noticeably colder. Always use cold water for drinking and cooking, especially in homes with lead service lines.
Conserve Water Resources
Though Milwaukee sits on Lake Michigan, water conservation helps protect this vital resource. Fix leaks promptly, install water-efficient fixtures, and participate in the city’s rain barrel program to reduce stormwater impacts.
Frequently Asked Questions
Is Milwaukee’s water safe from Cryptosporidium now?
Yes, Milwaukee’s water is now exceptionally safe from Cryptosporidium and other pathogens. Following the 1993 outbreak that affected over 400,000 residents, Milwaukee Water Works implemented comprehensive improvements to prevent any recurrence:
• Ozone Disinfection: Primary treatment using ozone, which is 100 times more effective than chlorine against Cryptosporidium
• Continuous Monitoring: Advanced real-time monitoring systems that can detect minute changes in water quality
• Multiple Treatment Barriers: Layered protection including coagulation, flocculation, sedimentation, filtration, and disinfection
• Watershed Protection: Expanded source water monitoring and protection programs
Since these upgrades were completed, no Cryptosporidium has been detected in Milwaukee’s finished drinking water, and the system has become a model for water safety worldwide.
Should I be concerned about lead in Milwaukee’s water?
Milwaukee’s source water from Lake Michigan contains no lead, but lead can enter water through service lines and household plumbing in older homes. Here’s what you should know:
• Milwaukee has approximately 70,000 lead service lines, primarily in homes built before 1951
• The city adds orthophosphate to create a protective coating inside pipes that effectively reduces lead leaching
• Current lead levels (7.4 ppb) are below EPA action levels but still present a concern in homes with lead plumbing
If you have a lead service line, the city recommends:
• Using certified filters for drinking and cooking water
• Running water for 3 minutes after long periods of non-use
• Using only cold water for consumption
Free water testing and filters are available by calling (414) 286-2830.
Why does Milwaukee test for so many more contaminants than required?
Milwaukee Water Works tests for over 500 contaminants—far exceeding the EPA-required 91—for several important reasons:
• Proactive Monitoring: After the 1993 Cryptosporidium outbreak, Milwaukee adopted a philosophy of comprehensive monitoring that extends beyond regulatory requirements
• Great Lakes Protection: As stewards of Lake Michigan, Milwaukee monitors for potential emerging contaminants before they become regulated
• Urban Watershed: Milwaukee’s urban setting introduces potential contaminants from stormwater runoff, industrial activities, and legacy pollution
• Research Leadership: As home to The Water Council and multiple water research institutions, Milwaukee serves as a testing ground for advanced water quality monitoring
This approach ensures that potential problems are identified early and addressed before they affect water quality or public health.
What is biologically active filtration?
Biologically Active Filtration (BAF) is an advanced water treatment process used by Milwaukee Water Works that offers several benefits:
• Natural Purification: Beneficial microorganisms grow on filter media and break down organic compounds that traditional filtration might miss
• Improved Taste and Odor: Effectively removes compounds that can cause earthy or musty tastes, especially during algae blooms in Lake Michigan
• Reduced Disinfection Byproducts: By removing organic matter before disinfection, BAF helps prevent the formation of potentially harmful byproducts
• Pharmaceutical Removal: Research shows BAF can reduce traces of pharmaceuticals and personal care products that may be present in source water
Milwaukee’s use of BAF, combined with ozone treatment, creates a powerful multi-barrier approach that produces exceptionally clean drinking water.
Contaminants of Concern
Lead
Source: Lead service lines and older plumbing fixtures in homes built before 1951; Milwaukee has approximately 70,000 lead service lines
Health Effects: Developmental delays in children, reduced IQ, learning difficulties, kidney problems, cardiovascular effects in adults
Current Levels: 90th percentile value of 7.4 ppb, below EPA action level of 15 ppb EPA Limit: Action level 15 ppb, but no level of lead is considered safe
Algal Compounds
Source: Seasonal algae blooms in Lake Michigan produce taste and odor compounds like geosmin and 2-methylisoborneol (MIB)
Health Effects: Not harmful to health but can cause earthy or musty tastes in water, particularly during summer months
Current Status: Effectively removed through ozone treatment and biologically active filtration; continuously monitored during algae bloom seasons
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