Water / Wastewater

Lake Michigan Info




Water Hardness Rating

Lake Michigan water has a hardness rating of 8 grains per gallon. Normal well-water typically has a rating of 13-28 grains per gallon.


The City of Chicago utilizes Lake Michigan as its source water via two water treatment plants. The Jardine Water Purifi cation Plant serves the northern areas of the City and suburbs, while the South Water Purifi cation Plant serves the southern areas of the City and suburbs. Lake Michigan is the only Great Lake that is entirely contained within the United States. It borders Illinois, Indiana, Michigan, and Wisconsin, and is the second largest Great Lake by volume with 1,180 cubic miles of water and third largest by area.

The City of Naperville purchases Lake Michigan water from the DuPage Water Commission since 1992. Lake Michigan water has a hardness rating of 8 grains per gallon. Normal well water has a hardness rating of 13-28 grains per gallon. This means that there are less dissolved minerals in Lake Michigan water, such as calcium and magnesium, which can cause scaling of glassware and in water heaters. The City of Naperville’s waters supply is chlorinated and fluoridated to comply with Federal and State regulations. Currently, an average of about 13 million gallons per day is consumed throughout the City of Naperville. To see more, please visit www.naperville.il.us/water.

Waste Water

The City of Naperville's Department of Public Utilities - Water has contracted with Michels Pipe Services to line approximately 16,033 linear feet of sanitary sewer mains in 2014-15. This contract is part of an ongoing program to rehabilitate the City’s oldest sewer mains using Cured-In-Place-Pipelining technology. The CIPP process avoids costly and disruptive excavation by inserting a custom-fitted liner into the existing sewer main. The liner, which is saturated with resins, is then heat-cured to form what is essentially a new pipe inside of the old pipe.

Wastewater rates consist of a fixed monthly service charge in addition to a per 100 cubic feet usage volume charge. During the summer, the volume charge is based on an average of the winter month water readings. The purpose of this is to avoid charging for extra water that is used during the summer months which does not enter the sanitary sewer system. There is no municipal tax on wastewater service. To learn more, please visit www.naperville.il.us/water.