By Samantha Pidde
Herald Staff Writer
The Clinton County Area Solid Waste Agency has until the end of the month to respond to Iowa Department of Natural Resources concerns about arsenic contamination from a closed landfill.
In a December letter to the CCASWA, the DNR expressed concerns about an increase of arsenic concentrations in ravine number two wells, which were first noted in 2007. CCASWA Engineer C.J. Lage, from Barker Lemar, said the contamination is from a landfill closed before 1989, used in the 1970s and 1980s.
"Who knows what went into the ravines at that time," Lage said.
At that time, landfills were not lined. Lage added that landfills were not required to meet the same guidelines as today.
Lage said that when Barker Lemar took over the landfills in 2002, storm water had seeped into that area, creating leachate. The engineers came in and reshaped the area to allow storm water to leave it. Lage added that in 2005, they put in leachate lines, without any prompting from the DNR, to send the leachate into a storage lagoon.
The CCASWA also has monitoring wells near the closed ravine, which Barker Lemar samples for contaminates. It was in the most recent sample that the DNR saw increased arsenic in a couple of the wells.
"While these increases have been noted in the current and past reports, no additional investigation into the cause or extent has been proposed. Therefore, the DNR is requiring additional groundwater assessment of the North MSWLF unit and you are required to submit an assessment plan by January 31, 2014," the DNR's letter states.
"Once a cause has been identified and the plume extend defined, the permit holder will be likely required to implement remedial actions, as the previous actions (leachate toe drain, improved capping) have not been sufficient to effectively control this off-site release."
Lage's staff is working on drafting a plan of attack for stopping any further contamination. Once a response to the DNR's letter is finished next week, it will be approved by CCASWA Director of Operations and Education Brad Seward and sent. A representative from the DNR would then let the agency know if the plan is reasonable.
Lage said it is really a matter of figuring out how far the pollutant goes. The company will most likely do additional sampling to see where the arsenic is coming from.
Another concern Lage hopes to address is the ownership of the property and wells close to the contaminated area. Currently that land is owned by a private individual. Lage said the agency would like to see if it could eventually purchase the property.
"Because owning any contamination back there would be a better place to be than not," Lage said.