Tackling pollution

Massive cleanup of River Raisin under way 

Boaters on the River Raisin are being urged to use caution in an area from the Port of Monroe turning basin to the river’s mouth at the Monroe Power Plant due to a massive environmental cleanup of river sediment that began Monday and will continue for months.

Dredges, a survey vessel, floating and submerged pipelines and a number of small utility vessels are dotting the area as part of a $13.7 million effort to clear pollution sediment from the depths of the waterway.

“Our goal is to keep this channel 100 percent safe,” said Loren Anderson, safety manager for J.F. Brennan Co. of LaCrosse, Wis., a federal contractor tasked with removing polluted and toxic sediment from portions of the riverbed closest to its banks.

Mr. Anderson was piloting a utility boat up and down the lower reach of the river in Monroe on Tuesday, pointing out the array of barges, pumps and other equipment that is part of the clean up process.

Signs saying “Danger: Submerged Pipeline” dot the watercourse and orange, heavy plastic piping can be see floating or partially submerged here and there.

Boaters should travel at no-wake speeds and stay within the red and green channel buoys in order not to run afoul of the operation.

The company began on Monday dredging areas where bottom sediment remains laden with high concentrations of polychlorinated biphenyls (PCBs), a now-banned fire retardant with cancer-causing properties that has been found in the fatty tissues of river fish.

The presence of the pollutant, likely from unknown industrial discharges, led to the stretch of river being listed among the Environmental Protection Agency’s areas of concern around the Great Lakes, where pollution problems make conditions unsafe for people and wildlife.

A Great Lakes Restoration Initiative grant is being used to try to rid the river of the remaining pollution.

A mechanical dredge, which has a front-end loader type of scoop on the front covered with a moveable lid, will scoop the most toxic sediment and load it into hoppers. The hoppers then will be lifted from the barge onto an asphalt pad specially constructed to process the waste. The water will be drained from the sediment and treated in a small on-site treatment plant, and the sediment will be mixed with a cement-like powder to thicken it. It then will be trucked to a hazardous waste landfill for disposal.

Tyler Lee, Brennan’s project manager, said an estimated 2,500 cubic yards of the hazardous sediment will be removed in a two- to three-week process. At the same time, about 105,000 cubic yards of less polluted sediment is being vacuumed from the bottom with hydraulic dredges and pumped through a two-mile long plastic pipe down to the river mouth and north to an Army Corps of Engineers disposal facility just north of Sterling State Park.

Meanwhile, a mountain of old dredgings from the disposal area has been trucked in and deposited on the grounds of Ford Motor Co’s River Raisin Warehouse — the former Monroe Stamping Plant — where it is being stored temporarily. The material is being removed to provide room for the sediment being dredged at the Corps’ disposal facility.

Mr. Lee said the dredging operation will last until at least October and will eventually run 24 hours a day, six days a week. So far, 23 workers are being assigned to the job. Some are staying at the River Raisin Marina & Campground adjacent to the company’s temporary base of operations.