A press release from the city of Minneapolis:

For the first time, runners taking part in the Medtronic Twin Cities Marathon will be drinking Minneapolis tap water at several water stops on the course. Organizers of the event are making the switch because Minneapolis tap water is clean, great tasting, and a better environmental and economic choice than bottled water.
The marathon, which begins in Minneapolis and ends at the state Capitol in Saint Paul, has several water stops along the course. Seven of the Minneapolis water stops will provide Minneapolis tap water to runners. They are at:

East River Parkway and Thornton Street SE
West 42nd Street at East Lake Harriet Parkway
James Avenue South at Douglas Avenue
East Minnehaha Parkway and Nicollet Avenue
West Lake Calhoun Parkway and Rose Lane
43rd Avenue South and Nawadaha Boulevard
Cedar Avenue South and East 49th Street

The annual Medtronic Twin Cities Marathon is organized and directed by Twin Cities In Motion, a non-profit corporation provides community supported, nationally recognized, high quality running events which attract athletes of all ages and abilities and promote health and fitness.

More about Minneapolis tap water

Minneapolis is the state’s largest producer of drinking water. We make around 60 million gallons of clean tap water every day that meets or is better than federal Safe Drinking Water standards. Unlike bottled water, which often costs more than gasoline, Minneapolis tap is a bargain at less than half a cent a gallon. Plus, drinking Minneapolis tap water is a better choice for the environment because it creates less waste: no shipping or single-use plastic bottles are needed for folks to enjoy it.

Minneapolis tap water is delivered to thousands of homes and businesses throughout Minneapolis, Bloomington, Columbia Heights, Golden Valley, Crystal, New Hope, Hilltop and the Morningside neighborhood of Edina.