MARSHALL, Mich. (Battle Creek Enquirer)--Large pipes, buoys and pontoon boats have been placed throughout sections of the Kalamazoo River as Enbridge Inc. works to fulfill an order by the U.S. Environmental Protection Agency to do additional cleanup.
"We're not talking about the oil that was in 2010," company spokesman Jason Manshum said at Enbridge's office in Marshall. "It's not flowing down the river. It's not a liquid anymore, either. It's more of a solid, it's flecks of oil. So it's degraded over time to the point that what is left are truly the size of flecks of pepper."
The 40-mile stretch of the river included in the EPA order requires dredging upstream of the Ceresco Dam, the Mill Ponds area in Battle Creek and the Morrow Lake delta in Galesburg. Manshum said Enbridge completed its work at a sediment trap location downstream of Historic Bridge Park about two weeks ago, allowing for the river between the park and Paddler's Grove to be reopened to the public.
The company also recently received approval for some dredging activity in Comstock Township after it was earlier denied a dredge pad permit at a site south of Morrow Lake. The township's planning commission later approved that area for housing woody debris removed from the river.
There are currently two dredge pad sites along the river: one near Ceresco and another by the Mill Ponds area, where work began about a week ago. Each has its own challenges, said Christopher Haux, senior manager of operations. The Mill Ponds operation is near larger amounts of woody debris and has a lot of polygons - enclosed areas where dredging is being done - while crews are dealing with a larger operation but mostly on a long channel of water in Ceresco.
"Ceresco's got more volume and the complexity of the dam, everything else," Haux said, riding on a boat through the Mill Ponds site. "This has got more logistical moving area."
The dredging process, in simple terms, is many steps of filtering. Crews set up containment areas and do some dredging with a pontoon excavator to remove woody debris and to allow for large equipment, while laying a high-density, polypropylene pipe through the river. Dredge equipment on boats then enters the area enclosed by oil booms, where "they'll work their way in, agitate out," Haux said.
"That boat will come in," he said, "and keep working its way in and out of there. It's like you're vacuuming."
The sediment is pumped through the pipes to large bags at a nearby dredge pad site. Polymer is added to the sediment inside the bag to help with containment, while the water is put through a treatment system and eventually returned to the river.
Haux said the equipment pumps 2,000 gallons per minute at the 100-acre site near Paddler's Grove, an Enbridge-constructed river-access point. Sixteen thousand gallons are pumped per minute at the Ceresco operation where the company "could treat enough for water for a city of 120,000 people," he said. The sediments are eventually run through a grinder/mixer called a pugmill and then shipped out to cover landfills.
"When we're done with each of the polygons, (teams) come back through and verify the survey and make sure that it's right," Haux said. "But the survey on the machine will give pretty close accuracy, we're just waiting for the agency signoff to make sure, 'yep, we did what we said we were going to do.'"
Survey teams include the EPA, he said.
Haux said about 30 employees are working on the dredging operation in Battle Creek and about 75 are in Ceresco.
"To put it in perspective," Manshum said, "at the height of our response, back in the summer, fall of 2010 - three years ago, we were on 2,500 people. Before we got this order, we were maybe 100 or a little less."
Close to 1 million gallons of tar sands oil poured into Talmadge Creek in July 2010 after a corroded portion of Enbridge's Line 6B pipeline split. It's considered the worst inland spill in U.S. history and closed the river for two years before it was reopened last summer. The company's latest figures have estimated cleanup costs at more than $1 billion.
It is replacing parts of the pipeline throughout Calhoun County, a move that would deactivate the old Line 6B and more than double the new line's capacity. Enbridge has said the project is an effort to reduce future maintenance activities. Local construction is expected to be completed by the end of this year.
EPA issued a final administrative order in March, asking Enbridge to remove the agency's estimated 12,000 to 18,000 gallons of recoverable oil. It said "future oil recovery will depend on whether the crude oil eventually moves to the areas with these sediment traps."
Work must be completed by Dec. 31 but Manshum said the work in Calhoun County, excluding operations at Morrow Lake in Kalamazoo County, is expected to wrap up in November.
About six miles of the river are currently closed for dredging operations, according to EPA's website.
"It's a temporary closure," Manshum said, "and it's only closed for safety reasons. You know, we've got heavy equipment in the river so we don't have recreational users - fisherman, kayakers, canoeists, et cetera, floating down the river, when we've got hydraulic equipment in there."
Closed areas will reopen in sections as work at each dredge site is completed, he said.
"The river was safe last year, it's safe today," Manshum said. "It will be safe after the dredging is done. It's just so that we can get the equipment and safely navigate."