RESTORATION OF AN URBAN LAKE: THE NEWBURGH LAKE PROJECT

摘要

Newburgh Lake is an impoundment located on the Middle Rouge River in WaynernCounty, Michigan. Newburgh Lake had the potential of being one of the valuablernrecreational areas in the urban metropolitan Detroit area. The history of the lakernencompasses over 65 years of sediment accumulation, some contaminated withrnPCBs, which over time, degraded the lake water quality. Shallow water depthsrnresulting from the sediment accumulation and nutrient-rich water led to excessiverngrowth of aquatic plants and the presence of organic contaminants such as PCBs thatrntend to bioaccumulate, as they pass up through the food chain, resulted in a potentialrnhuman health hazard.rnThe construction to remediate and restore Newburgh Lake, thereby returning thisrnvaluable resource to the citizens of the region, began in April 1997 after initial studiesrnand design had been completed. The most challenging phase of the project was thernexcavation and removal of 558,000 tons of sediments, much of which wasrncontaminated with PCBs. Sediments were excavated by use of dredges, draglinesrnand conventional equipment. Complicating the process was the varying nature of thernsediments in the lake bottom, the urban setting, various storm events and anrninterceptor sewer that runs along the lake bottom.rnBeyond sediment removal, 7 acres of fish spawning beds and habitat structures werernbuilt throughout the lake bottom; 10 acres of beneficial aquatic vegetation were plantedrnin constructed shoal areas; 28,000 pounds of PCB contaminated fish were eradicatedrnand removed from the lake and its adjacent waterways; over 30,000 fish of variousrnspecies were restocked; and numerous shoreline and infrastructure upgrades werernmade to enhance the recreational use of the surrounding park area. The total cost forrnthe project including the cost of excavation, restoration, disposal, engineering designrnand construction management was $11.8 million dollars.