The City of McCook Sewer Department operates and maintains 50 miles of collections mains ranging in size from 36 inches to four inches. The system uses both gravity and force mains to collect and send sewage to the Waste Water Treatment Facility, located just southeast of town.
The Treatment Facility was upgraded in 2006 to provide additional ammonia removal, allowing capacity to remain at 1.75 million gallons per day. The plant currently operates at approximately 0.7 million gallons per day. The plant uses clarifiers, rotating biological contactors, and biological aerated filtration to remove impurities from the waste water.
The Sewer Department is operated by four licensed operators, governed by the City Council, and under the direction of the city manager and utility director.