Dirty roadside runoff
BIG BAY – Workers on a project to upgrade Marquette County Road AAA in Champion Township recently struck a perched groundwater seep, accidentally allowing water and sediment to make its way into the East Branch of the Salmon Trout River.
The problem occurred during road construction near a place where the Marquette County Road Commission will construct a new 95-foot clear span bridge over the river, replacing three culvert crossings.
Contractors working for the road commission were making a roughly 80-foot road cut.
“There was a pretty large cut, it exposed a perched groundwater seep,” said John Gustafson, an environmental quality analyst with the Michigan Department of Environmental Quality’s Upper Peninsula District Office. “They unexpectedly hit that seep.”
Gustafson said the receiving water contained sediment deposits and unnatural turbidity as a result of the discharge, in violation of provisions of the Natural Resources and Environmental Protection Act.
On July 14, DEQ Water Resources Division staff inspected the site with road commission personnel. At that time, soil erosion and sedimentation control measures put in place by the road commission were keeping sediment from being discharged from the site.
Four days later, DEQ staff again inspected the area in response to a complaint.
“Water Resources Division staff observed the unlawful discharge of sediment and turbid water to a wetland ravine, tributary to the East Branch Salmon Trout River and the East Branch proper,” Gustafson said in a violation notice letter to the road commission. “Groundwater flows increased as the cut deepened and when combined with a recent rain event, the soil erosion and sedimentation control measures failed and the discharge of sediment occurred.”
The road commission had installed additional control measures to help prevent further discharge before DEQ staff arrived. The following day, in consultation with the DEQ, the road commission installed a polymer to catch clay suspended within the turbid water.
“We gave them direction to do the restoration,” Gustafson said.
DEQ staff returned to the site on July 22. Just before the visit, the area received a large amount of intense rainfall.
“The discharge water from this area was observed to be clear and sediments were retained on site,” Gustafson said in the letter.
That same day, DEQ staff saw the river – upstream from the uppermost of the three culvert crossings – was clouded after the heavy rain. Potential sources of the turbidity in the river and a pond were investigated and later determined to likely be road runoff from County Road AAA to a cross drainage culvert, Gustafson said.
“The cross culvert discharges water through stable harvested forest ground prior to discharging to the pond,” Gustafson wrote.
DEQ staff said the new free span bridge to be built over the river will fix runoff sedimentation problems historically recorded at the three culverts.
“We believe that it’s going to be an eventual benefit by eliminating those sources of sediment,” Gustafson said.
In a management plan developed for the Salmon Trout River watershed, the Superior Watershed Partnership estimated the three culvert crossings along the road dumped 224 tons of sediment into the river each year. That sediment totaled more than two-thirds of the sediment load from 29 road crossings surveyed in 2005 and 2006.
On July 29, the DEQ confirmed the groundwater seep was being infiltrated back into the ground and water discharge had ceased. The road commission agreed to remove by hand sediment deposited in some selected portions of the wetland and the intermittent stream leading to its confluence with the river.
The road commission will continue to monitor the color and clarity of the water upstream from the road crossing and the pond, to see if additional action is warranted.
Gustafson said no adverse impact has been noticed so far. The DEQ said the road commission has taken steps and agreed to additional action to regain and maintain its compliance with the law at the site.
Marquette County Road Commission Engineer-Manager Jim Iwanicki declined to comment on the situation other than to say the facts of what occurred were laid out in Gustafson’s letter to the agency.
The groundwater seepage problem was reported anonymously to the Yellow Dog Watershed Preserve. Members of the group visited the site on several instances.
The preserve made a formal complaint to the DEQ Aug. 1 and urged the agency to issue a citation to the road commission for polluting the water and require a mitigation plan to clean up the site be developed and implemented.
Members of the group also reported the incident to the Environmental Protection Agency and tribal officials.
Gustafson’s violation notice letter was sent to the road commission Aug. 4.
John Pepin can be reached at 906-228-2500, ext. 206. His email address is email@example.com.