Utilities - Wastewater Department
Water/Sewer Billing Office, 333 W.
Ellsworth St., Midland, MI 48640 Phone: 989-837-3341
Wastewater Treatment Plant, 2125 Austin St., Midland, MI 48642 Phone: 989-837-3500
Wastewater Treatment - A Complex Recycling Process
The City of Midland's Wastewater Treatment Plant has been in
existence since 1939, when the first plant - then located on Wyman
Street at the foot of Ashman Street - treated up to 2 million
gallons per day in a combined storm and
sanitary sewer system.
Over the years, this system has been reconfigured and enhanced. Today,
Midland's Wastewater Treatment Plant is capable of treating up to 18 million gallons of wastewater a day,
though on average, the plant treats 5 to 7 million gallons each day. There are
195 miles of
sanitary sewer and 41 pump stations throughout the city.
In addition, a 43.5 million-gallon storage basin adjacent to the treatment
plant has the capability to temporarily store sanitary sewer flows that go
beyond the capacity of the plant.
Visual of the Flow Process
How the System Works
Wastewater from throughout the city travels through
by way of both gravity and pressure. The pressure method involves pump stations,
which convey water through force mains to the Wastewater Treatment Plant.
Once at the plant, the sewage undergoes a complex treatment process designed
to filter out debris and clean the water according to State regulations before
it is discharged to the Tittabawassee River.
The City's treatment facility is comprised of 12 buildings and a myriad of
tanks and ponds that are used to screen out debris and settle out sludge and
grit - such as coffee grinds - from the wastewater. This debris is dewatered and
collected in holding containers and periodically hauled to the Midland Sanitary
Landfill for burial.
After the debris has been removed and the water flow has been measured, the
water continues through a recycling process that involves chemical and
biological treatments. During the biological treatment phase, microorganisms are
used to break down organic materials in the wastewater, which further cleans the
The City of Midland's treatment plant has two separate biological treatment
systems, which is unique in Michigan: most facilities usually have only one
Sludge that settles out during and after these treatment phases is pumped to
a digester system, which stabilizes the sludge. The resulting product is called
biosolids, which are returned to the earth as nutrient-rich farmland fertilizer.
Any bacteria that remain after
the biological treatment phases are killed by chlorine gas that is injected into
the water in the next phase of the treatment process.
In the last treatment phase, water is dechlorinated using sodium bisulfite. The final product is then discharged to
the Tittabawassee River.
Along every step of the way, trained wastewater operators monitor the
equipment that controls the treatment processes and perform tests on the water
in compliance with State law. The wastewater plant is staffed 24 hours a day,
365 days each year to ensure that the system is working properly, efficiently
The result of the above processes and the hard work of highly trained
professionals at the treatment plant is effluent that is returned to nature without harm to humans, wildlife, lakes and
other waters of Michigan.