The Minnesota Pollution Control Agency (MPCA) today released its initial environmental assessment worksheet (EAW) for the planned expansion of the Dem-Con Landfill in Scott County. Dem-Con, LLC has proposed a 241-acre expansion area to continue to meet the region’s industrial, construction, and demolition waste disposal needs.
The initial assessment reviewed potential impacts to local geology, soils, groundwater, surface water, and other potential environmental impacts. Some key findings are:
- The project area does not contain any surface waters, wetlands, or floodplains and is not in a wellhead protection area.
- The depth to groundwater ranges from two to 20 feet below the floor of the quarry. Impacts to groundwater from a landfill generally result from leachate production. Dem-Con has implemented several groundwater protection measures including a synthetic liner with leachate collection and multiple final cover layers to prevent the infiltration of precipitation.
- Existing groundwater monitoring networks will be expanded to include the project area. Groundwater monitoring occurs on a quarterly basis.
- An existing stormwater pond will be expanded from three acres to 13.6 acres to accommodate more stormwater runoff.
The proposed expansion area is directly south of the current landfill and is an active limestone quarry that is nearing completion and preparing for final reclamation activities and end-use development. The expansion would allow the landfill to accept additional construction, demolition, and industrial waste disposal capacity, but not municipal solid waste.
Once environmental review has been deemed complete, Dem-Con has proposed to begin construction of the initial phase of the expansion area in 2023. Phases are filled and developed over time with an estimated remaining life of 55-60 years. Without the expansion, the estimated life of the landfill is less than 10 years.
The MPCA invites the public to comment on the assessment. Residents should consider the worksheet’s accuracy, potential impacts from the project that warrant further investigation, or the need for an environmental impact statement.
The public can review the draft EAW and submit public comments by visiting www.pca.state.mn.us/publiccomments or by mail to:
Minnesota Pollution Control Agency
c/o Charles Peterson
520 Lafayette Road
St. Paul, MN 55155
After the public comment period is complete, the agency will review all comments and determine whether additional environmental review will be necessary. If the agency determines there is no need for additional environmental review, the project will proceed to permitting.