Contamination conundrum: State still working to clean up site of former Bemidji wood treatment plan
Source: http://www.bemidjipioneer.com, August 13, 2015
By: Matthew Liedke
After years of studying contaminated groundwater left behind from a wood treatment plant in Bemidji’s Industrial Park, the state again is preparing to take corrective action.
The Minnesota Department of Agriculture has wells set up at 944 Industrial Park Drive SE and 781 Carr Lake Road SE, which are being used to determine how much groundwater is contaminated, how far the contamination has spread and also how best to fix the problem.
According to Greg Hanson, project manager with the MDA, the state has been involved with the site since the late 1990s; however, the contamination began in the early 1970s.
From 1971-1980, the groundwater in the area was contaminated with pentachlorophenol, or PCP, as a result of Cedar Services’ plant, where products such as telephone and power poles were treated.
The Minnesota Department of Health states that PCP is a manufactured chemical used widely for preserving wood in exterior settings and that it was widely restricted in the mid-1980s.
Nearly two decades after Cedar Services ceased its Bemidji operations, the federal Environmental Protection Agency responded with cleanup operations, such as soil excavation and tank and sludge removal in 1997 and 1998 before turning it over to the state.
Initially, the site work was under the supervision of the Minnesota Pollution Agency before it was transferred to the Department of Agriculture.
“When we took over, we made it a priority to expand the investigation,” Hanson said. “We’ve now had wells in there since 1998 and we’ve put more in this year.”
“The challenge is the contamination is so deep,” said Jim Seaberg, a hydrogeologist for the department. “The groundwater is 30 feet below the surface, making it difficult to dig up sources.”
The ag department has reached the point where it can take action to improve the situation, though, by constructing new wells with the purpose of injecting other chemicals into the water.
“What we’re planning on doing is called chemical oxidation, to break the PCP down to harmless substances,” Seaberg said. “We’ve done this in other soil and it’s been successful. So we are doing the research and field applications to make sure it will work under the conditions in Bemidji.”
Along with the injection wells, three more testing wells are scheduled to be installed this year. While the injection wells add chemicals to neutralize the contaminants, the other wells will be used to monitor the results and test the effectiveness. Hanson said the department will likely expand the injection well operation in 2016 after reviewing the initial results.
For projects involving corrective action, the agency is required to hold a public comment period, which is open until Aug. 31. Local residents can submit comments or questions about the well operation to Hanson at 625 Robert St. N., St. Paul, 55155.
Hanson said the department has already been in contact with officials and businesses in the area regarding the work.