Frasier Shipyards, Wisconsin DNR outline Howard's Bay remediation, city briefed on disposal options

Frasier Shipyards and the Wisconsin Department of Natural Resources told the Superior Common Council on Sept. 16 that a federally funded feasibility study and remedial design is under way for contaminated sediments in Howard's Bay and that the city may be asked to take a formal partner role when the project moves to construction.

The update — presented by Tom Carilli, director of operations at Frasier Shipyards, and Joe Graham, Lake Superior sediment and monitoring coordinator for the Wisconsin DNR — laid out contaminants including lead from paint and a class of organotin compounds the presenters referred to as “tributyls,” described an estimated timeline and flagged disposal as a major outstanding issue.

The project is using legacy funds from the U.S. Environmental Protection Agency under the Great Lakes Legacy Act and is coordinated with the U.S. Army Corps of Engineers, the DNR and private industry, Carilli said. He told the council the current work is a fixed-fee feasibility study and remedial design with a nonfederal sponsor contribution of roughly 35 percent and a design budget of about $710,000.

"We don't want to spread contamination around," Carilli said, describing the technical work required before dredging and disposal. He said the partners expect the remedial design to take about a year and that construction could begin in 2015 if schedules align with the Corps' navigation dredging.

Carilli told the council the Corps needs the federal navigation channel in Howard's Bay maintained to 27 feet; Corps maintenance dredging is contingent on having an allowable disposal plan for any contaminated material encountered. Joe Graham and Frasier representatives said some dredged material will be clean enough for placement in a phase-3 embayment at the shipyard, but other material will be unsuitable for immediate in-water placement and will require a different disposal path.

Councilors pressed for quantities and technical detail. "The total dredge material is probably approaching 100,000 cubic yards," Carilli said; he added the contaminated portion could be "possibly 40," a figure discussed in the meeting as roughly 40,000 cubic yards but not finalized in the presentation. Councilor Sweeney asked for a firmer estimate; Carilli said more precise numbers should be available as the design work progresses.

Questions also covered how much of the contamination lies within the federal channel versus private slips and the varying depths of sediment overlying clay. Councilor Herrick asked whether the contamination overlapped the 27-foot channel; presenters said contamination is largely outside the channel but exists in steep slopes adjacent to it.

Presenters said disposal alternatives under consideration include staged drying, reuse in local projects and placement at the Moccasin Mike landfill, but the DNR has determined that contaminated sediment cannot simply be returned to the water. City staff are already supplying technical data on whether the Moccasin Mike landfill (referred to during the meeting as “Moccasin Mike” or “Mox and Mike”) could accept certain fractions of the material, and presenters said final decisions will depend on the remedial design and regulatory determinations.

The council formally moved to "receive and file" the presentation; the motion was seconded and approved.

The council was briefed on next steps: the feasibility and remedial design funded through legacy EPA money will continue for about a year, partners will refine quantity and disposal estimates, and the city will be asked to confirm what in-kind or other contributions it can make if it becomes a named nonfederal sponsor for construction.