In the late 1990s, the Environmental Protection Agency declared the area to be an environmental concern due to the level of pollutants in Lake Erie and the River Raisin. When studying fish in the area, PCB levels increased 87% from the 1988 to 1998. The result of the overpollution came from the sudden industrial growth surrounding the River Raisin delta and Lake Erie. The largest of these industries include a Ford plant and the coal-burning Monroe Power Plant, both of which caused severe impacts on the ecosystem of the area. In September 1997, the Ford completed an environmental dredging project in the River Raisin and removed approximately 25,000 cubic yards (19,000 m³) of toxic PCB-contaminated sediment from the River Raisin.