What Residents Need to Know About Milwaukee Water Quality

Where Does Milwaukee’s Tap Water Come From?

Milwaukee’s tap water comes from Lake Michigan, one of the five Great Lakes. Under the U.S. Safe Drinking Water Act, the Wisconsin Department of Natural Resources is required to conduct a source water assessment of the drinking water system.

Since the lake’s drainage area is so big — more than 45,600 square miles — the report focuses on the 882 square miles that drain directly into Milwaukee Harbor, including the Milwaukee, Kinnickinnic, and Menomonee Rivers.

The report contains an inventory of potential contaminant sources, including:

• Landfills
• Cemeteries
• Golf courses
• Airports
• Railroads and switchyards
• Construction sites
• Pipelines
• Septic systems
• Wastewater treatment facilities

According to the report, Milwaukee’s source water was found to be “highly susceptible to contamination” by a variety of organic, inorganic, and microbial contaminants — but implementing source water protection strategies like better runoff management could significantly improve surface water quality in Milwaukee.

How Is Milwaukee’s Drinking Water Treated?

Like other American drinking water systems, Milwaukee’s drinking water goes through a multi-step treatment process before it comes out of the tap. These steps include:

• Ozone disinfection: Ozone is used to kill Giardia and Cryptosporidium, as well as to improve the taste and smell of the water.
• Coagulation and flocculation: MWW uses aluminum sulfate to cause particles to clump together into “flocs” that can more easily be removed.
• Sedimentation: Flocs settle to the bottom of the water and are removed.
• Filtration: MWW uses biologically active filtration, including 2 feet of anthracite coal and 1 foot of sand, to filter smaller particles out of the water.
• Disinfection: Chlorine is used to kill viruses and bacteria; later, it’s converted to chloramine with the addition of ammonia.
• Corrosion control: MWW adds phosphorus to the treated water to keep lead and copper from leaching into the water from the distribution system.

These steps go a long way toward providing clean water to Milwaukee residents and to meeting the requirements of the U.S. Environmental Protection Agency (EPA). However, some contaminants may still be present, and the water treatment process may result in the presence of disinfection byproducts like chloramine and bromate.

Milwaukee Water Works performs testing for over 500 contaminants, and publishes the test results in its annual Milwaukee water quality report.

What Contaminants Are Found in Milwaukee’s Drinking Water?

Milwaukee water quality has improved significantly since 1993, when a Cryptosporidium outbreak led to waterborne illness throughout the city. After spending over $508 million on water treatment and testing infrastructure, the “risk of becoming ill from ingesting Milwaukee water has been all but eliminated,” according to MWW.

Still, microbial contaminants aren’t the only water quality concerns in Milwaukee, and long-term exposure to other contaminants may present a public health risk.

Here are five contaminants to look out for in Milwaukee tap water.

Total trihalomethanes (TTHMs)

Disinfection of the water supply is an important part of the treatment process, but it can result in undesirable levels of disinfection byproducts. One group of chemicals, called trihalomethanes, may increase the risk of cancer with long-term exposure.

Milwaukee’s TTHM levels are lower than the EPA’s legal limit, but 50 times higher than the Environmental Working Group (EWG) recommends for safe exposure:

• EPA maximum allowance: 80 ppb
• EWG recommended maximum: 0.15 ppb
• Milwaukee maximum contaminant level: 7.51 ppb

Haloacetic acids

Haloacetic acids are another category of chemicals left behind when disinfectants like chlorine are used in the water treatment process. According to the EWG, they pose a risk of cancer and harm to fetal growth when consumed in large quantities.

One group of haloacetic acids (HAA9) has no legal limit, and is found in Milwaukee tap water at levels 75 times higher than the EWG’s recommendation:

• EPA maximum allowance: No legal limit
• EWG recommended maximum: 0.06 ppb
• Milwaukee maximum contaminant level: 16.8 ppb

Nitrates and nitrites

Nitrates and nitrites are chemicals that contaminate the water supply due to runoff from farms and septic taps. High levels of exposure are linked to developmental issues such as methemoglobinemia, or blue baby syndrome.

Fortunately, nitrate and nitrite levels in Milwaukee’s drinking water are low, but they’re still 2.2 times the EWG’s recommended maximum:

• EPA maximum allowance: 10 ppm
• EWG recommended maximum: 0.14 ppm
• Milwaukee maximum contaminant level: 3.02 ppm

Arsenic

Arsenic is a heavy metal that can lead to arsenicosis, or arsenic poisoning, over time. It’s most common in areas that rely on groundwater wells, but there are still notable levels of arsenic in the Milwaukee water supply:

• EPA maximum allowance: 10 ppb
• EWG recommended maximum: 0.004 ppb
• Milwaukee maximum contaminant level: 0.0875 ppb

Chromium (hexavalent)

Chromium-6, or hexavalent chromium, is a pollutant made famous by Erin Brokovich due to its effect on residents in Hinckley, California. Although the EPA regulates total chromium levels, it doesn’t regulate chromium-6, which is found in low to moderate levels in Milwaukee’s drinking water:

• EPA maximum allowance: No legal limit
• EWG recommended maximum: 0.02 ppb
• Milwaukee maximum detected level: 0.213 ppb

Is Milwaukee’s Tap Water Safe to Drink?

Whether or not Milwaukee’s tap water is safe to drink depends on your personal health circumstances and your interpretation of the water quality data. People with underlying health conditions may be more at risk of waterborne illnesses than others.

Your best bet is to choose a home water filter system that’s rated to filter out specific contaminants of concern. For example, activated carbon filters and reverse osmosis systems are both proven to reduce levels of haloacetic acids and TTHMs.

Other types of filters, like UV light water treatment, can kill viruses and bacteria, but won’t remove heavy metals like arsenic and lead.

Does Milwaukee’s Drinking Water Contain Lead?

According to Lead-Safe Milwaukee, Milwaukee’s drinking water “meets all federal and

state guidelines when it leaves the treatment plants,” but it can pick up lead along the way from water service lines and plumbing fixtures.

Milwaukee Water Works uses corrosion control measures to reduce the levels of lead leaching out of pipes and water mains, and is replacing up to 65,000 service lines that still contain lead. Levels of lead have declined significantly since 1993, and are below the EPA’s action level of 15 micrograms per liter.

Still, residents can take steps to reduce exposure by using an NSF/ANSI 53 filter and only using cold tap water for cooking and drinking, which is less likely to draw lead from your pipes than hot water.

Does Milwaukee’s Drinking Water Contain PFAS?

Forever chemicals, or PFAS, are another category of environmental contaminants that can lead to health problems with long-term exposure. Milwaukee has been testing for PFAS since 2008, and has reported low levels of contamination.

Still, the proximity of airports and military sites to the Great Lakes could pose a risk to residents, with private drinking wells near these sites at the highest risk.

Residents who are concerned about PFAS should consider a reverse osmosis water filter, which is more effective at removing PFAS than an activated carbon filter.

Is Milwaukee’s Drinking Water Fluoridated?

Yes, Milwaukee adds fluoride to its drinking water at a level of 0.7 milligrams per liter. This is the amount recommended by the U.S. Public Health Service to provide “oral health benefits while minimizing potential harms, such as dental fluorosis.”

Is It Safe to Swim in Milwaukee?

Milwaukee’s surface water sources aren’t just used for drinking — they’re also popular for boating, swimming, and other recreational activities. But is it safe to swim in Lake Michigan and the Milwaukee River?

According to Milwaukee Riverkeeper, sewage and stormwater overflows can increase the risk of bacterial illness. They recommend using the Swim Guide app to check the conditions at local beaches before diving in.

How Do Algal Blooms Affect Milwaukee Water Quality?

Algal blooms are another growing concern in the Milwaukee area. Blue-green algae, also called cyanobacteria, produce toxins that are dangerous for people and pets.

Algal blooms look like surface scum, and can appear anywhere from inland lakes and rivers to Lake Michigan itself. Researchers at the University of Wisconsin-Milwaukee (UWM) are studying ways to reduce algal blooms by limiting agricultural runoff and using “bioswales,” or stormwater channels, to filter out excess nutrients.

The state of Wisconsin is also participating in CyAN, the Cyanobacteria Assessment Network, a project that uses satellite data to track algal blooms at over 150 lakes.

Should You Drink Milwaukee’s Tap Water?

Milwaukee’s tap water meets or exceeds public health goals for several contaminants, but it falls short in other areas, including disinfection byproducts and lead. Despite the city’s efforts to replace lead service lines, lead remains a concern for many residents, while algal blooms and PFAS exposure threatens the surface water supply.

It only takes a few minutes to install an under-counter water filter and remove some of the most common contaminants of concern from your water supply. For even more protection, install the UPSTREAM™ 4-Stage Whole Home Water Filter to get four stages of water filtration and remove chlorine, PFAS, heavy metals, and more.

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