Posted on April 20, 2017
By Don Behm, Milwaukee Journal Sentinel
Like massive shop vacuums on floating platforms, two hydraulic dredgers started sucking contaminated muck off the bottom of Cedar Creek on Monday as part of Mercury Marine’s ongoing removal of toxic chemicals from the stream.
Dredger operators are guided by GPS to previously identified sediment layers containing unsafe amounts of industrial chemicals known as PCBs, Mercury Marine project manager Craig Dousharm said.
As the muck is lifted up, pumps on each platform push the load through an orange-colored pipeline suspended in the water to a field at Adlai Horn Park. Pedestrians or motorists passing the park off Columbia Road have seen its gradual transition since last year from recreational fields to a three-acre black mat marking the location of a special water treatment plant and sediment storage yard.
Contractors for Mercury Marine have begun the second and final year of a $24.8 million cleanup of a section of the creek and floodplain that extends from the Ruck Pond dam downstream to the Wire & Nail factory dam. This stretch of the stream includes Columbia Pond, an impoundment behind the Columbia Mills dam; and Wire & Nail Pond, held back by the former factory dam.
The cleanup plan approved by the U.S. Environmental Protection Agency calls for removing 98% of the PCBs from the two impoundments. A total of 55,000 cubic yards of contaminated sediment — weighing in at 80,000 tons — will be dredged out of the creek.
Source: Milwaukee Journal Sentinel
