Best Project Water/Environment: Morrow Lake Remediation
In spring 2010, an oil pipeline burst, discharging more than 800,000 gallons of oil into Michigan’s Kalamazoo River. The remediation of the Morrow Lake and Delta areas began in 2014.
The project employed more than 30 dredges, barges and other pieces of heavy equipment—along with approximately 10,000 linear ft of dredge pipe—within a 327-acre operational area accessed through one entry/exit point. To minimize traffic, crews utilized remote-operated booster pumps, which reduced the labor requirements and associated support equipment. Post-dredging surveying confirmed that remedial action levels were achieved.
Five hydraulic dredging units, outfitted with GPS positioning equipment, operated in close proximity to each other. Each dredge—with at least one booster pump and up to four booster pumps at the farthest reaches of the dredge area—removed, treated and transported 89,500 cu yd of sediment. A total of 136,400 tons of sediment and dredge pad materials were removed.
This dewatering pad was just under 1.1 million sq ft with a total of more than 100,000 cu yd of topsoil and subgrade moved and repositioned. The pad was constructed with a liner placed in three layers and topped with 60,000 tons of 21AA aggregate and 30,000 tons of 6A aggregate.
The dredge-slurry management system proved efficient, operating at 99.7% efficiency during the project, with five separate dredge units feeding the system from various locations as much as two miles away, project officials note.
During bag field operations, there were no bag failures out of 28 large dewatering bags utilized and no fill hose failures out of 85 separate hoses. The water treatment system was capable of treating 12.5 million gallons per day, and more than 198 million gallons of water were treated during this project.
Morrow Lake Remediation
Lead Design Firm Terra Contracting Services LLC, a Great Lakes Dredge and Dock Co.
Contractor Terra Contracting Services LLC
Civil Engineer Leggette, Brashears & Graham Inc.
MEP Engineer Ryba Marine Construction
Subcontractors Global Environmental Engineering Inc.; SWAT Consulting Inc.