The EPA and companies responsible for the waste in this area, which includes a three-mile section of Portage Creek as well as part of the Kalamazoo River, into which it flows, are currently involved in an effort to reduce the amount of toxic waste at the site, which is contaminated by PCBs (polychlorinated biphenyls) from paper mills and other factories.

[2] The Kalamazoo Superfund site was added to the National Priorities List on August 30, 1990, and the First Cleanup Action began in late 1990.

[1] Between 1990 and 2000, under an agreement with the EPA and the State of Michigan, several of the current and past owners of plants that had been responsible for the contamination investigated the Portage Creek site.

[3] Polychlorinated biphenyls (PCB) constitute a wide array of now-banned organic chemicals with a variety of industrial applications.

[5] A report by the Michigan Department of Health in 2002 found that the Kalamazoo River is now safe for recreational use despite some PCB contamination.

[7] The Comprehensive Environmental Response, Compensation and Liability Act, which was passed in 1980, calls for the cleaning up, under EPA supervision, of abandoned hazardous waste sites that release pollutants into the environment.

Sites with Hazard Ranking System Package scores of 28.5 or higher out of 100 are placed on the NPL, pending official approval.

[1] Two of the Operable Units, King Highway Landfill and Allied Inc., had sheet pile and caps installed, a process which does not remove PCBs but serves as a protective layering containing them.

[11] On December 21, 2016, EPA issued a Unilateral Administrative Order to Georgia-Pacific, International Paper and Weyerhaeuser to conduct the work specified in the record of decision.

EPA has been working with the bankruptcy Trustee for Allied Landfill to implement the design for the cleanup selected in the September 21, 2016, Record of Decision.

In the later summer of 2018, the EPA completed the removal of PCB-contaminated sediment and soil along the Kalamazoo River near the Otsego Township Dam.

The selected cleanup plan requires the excavation and off-site disposal of contaminated soil from the former mill site.