28 Jun How is Mankato’s drinking water cleaned?
Mankato’s drinking water has passed and exceeded federal and state drinking water tests. However, where does this clean water come from and how does the Mankato water treatment facilities make it happen?
Drinking water guidelines
Before understanding how Mankato gathers and cleans its water, it is important to know the guidelines to which they are following. Mankato, along with the rest of the United States, follows The U.S. Environmental Protection Agencies safe drinking water standards. These standards limit the number of contaminants allowed in drinking water. The city of Mankato also publishes an annual drinking water report, the latest dating from January 1 to December 31, 2018. This report details how Mankato’s water is being cleaned, the contaminants found and tested and much more.
Where does the water come from?
Mankato’s drinking water is drawn from groundwater sources. in fact, 75 percent of Minnesota’s drinking water comes from groundwater. Mankato uses five wells that draw from different aquifers, Mt. Simon, Tunnel City-Mt. Simon and Quaternary Water Table aquifers. After this water is drawn from these deep and shallow wells it is pumped to Mankato’s water treatment plant to be cleaned.
Drinking water treatment
Once this water is received the water begins its treatment process. The plant uses ultra-membrane filters to protect the water against bacteria and viruses.
In early 2000 Mankato committed to using membrane filtration. In 2008 Mankato’s water treatment plant began using the ultrafiltration system. Membrane filtration is a type of filter packed so tightly they are capable of blocking small viruses and bacteria. The city of Mankato website states the membrane filtration system has filtered the size of a single strand of human hair. Mankato’s water treatment plant compares it to 11,000 bar straws in an 8” pipe. Before the membrane filtration, sand filters were used.
The city of Mankato’s website states the plant tests for more than 100 contaminants and warns that no water can ever be completely free of them. The water quality report included six categories of contaminants, ranging from lead and copper to inorganic and organic contaminants. Each of the contaminants has its own chart that describes where the contaminant was tested, the EPA’s action level, typical sources and more.
After the water is treated it is pumped to water storage reservoirs. Mankato has nine water storage facilities that can hold 11.45 million gallons of drinking water. From these reservoirs, the water is pumped to water towers and then distributed for public use
Mankato’s water treatment process is one that is open for tours. The water treatment facility is open 24 hours a day and encourages questions. The city of Mankato lists these three individuals to contact for more information.
Mark Winson, Director of Public Utilities, 507-387-8583, [email protected]
Jim Brueder, Public Utilities General Superintendent, 507-387-8666, [email protected]
Kyle Hinrichs, Foreperson of Water Treatment Plant, 507-387-8588, [email protected]