SENECA — In the aftermath of the Nov. 16 collapse of a 3½-acre section of permanent soil cap at the Ontario County Landfill, several mitigation steps have already been taken and are continuing.
A large pile of soil from a seven-acre area on an inactive portion of the 389-acre landfill accumulated at the bottom of the slope, affecting some landfill gas-collection wells and pipes.
The cause of the collapse, and the mitigation plan, is being handled by Carla Jordan, the county’s director of Sustainability and Solid Waste Management; officials from Casella Waste Services of Ontario, operator of the landfill; and the state Department of Environmental Conservation’s Region 8 office in Avon.
On Friday, Jordan said these five steps are being taken:
• Contractors at the site continue to move soil off the impacted slope.
• In order to ensure the remaining section of cap was not at risk of sliding, a decision was made to cut the synthetic liner at the southwest corner of the site. That is the felt-like material that sits on top of the textured 40 milliliter cap. Jordan said this will help ensure the liner and soil that slid down do not pull down the adjacent area of the constructed cap on the south slope.
• The gas wells impacted by the soil sliding have been found, dug out, and capped.
• Stormwater controls remain a priority. By the time rain arrived Nov. 17, a system of pumps had been set up to move stormwater away from the impacted area. In addition, a diversion berm was constructed at the bottom of the impacted slope to ensure stormwater did not cross over the berm road. Jordan said these controls have been working as designed and there continues to be no impact on of the landfill’s footprint.
• Once the majority of the soil has been removed, the site will reestablish the stormwater infrastructure already there to ensure that all stormwater from the slope can flow to the on-site detention infrastructure, as originally designed.
“I have discussed all of these actionable items with the DEC staff in Avon and they continue to be in agreement with these site efforts,” Jordan said.