Monticello Winfield South Mine
SKA Consulting was retained by Luminant Mining Company, LLC to manage a groundwater recovery and treatment system installed at a mine office, shop and warehouse complex. Approximately 4,000 gallons of diesel was released from the off-road vehicle fueling system at this facility. Rapid assessment and initial abatement removed the majority of the contaminated soil; however, a non-aqueous phase liquid (NAPL) plume still developed in groundwater. The recovery system was designed and installed by SKA’s senior engineer to perform total fluids recovery of groundwater and PSH, and provide hydraulic control of plume migration and groundwater depression to induce PSH flow to the recovery wells. Treatment included oil/water separation, air stripping, and granular activated carbon polishing before surface discharge.
SKA conducted monthly operation and maintenance of the system from August 2004 through April 2008 in which time the system recovered a total of 4,500 gallons of PSH. Quarterly groundwater monitoring was conducted for the 26 groundwater monitoring and recovery wells and annual reports were submitted to the Texas Commission on Environmental Quality (TCEQ) summarizing the results of the groundwater remediation.
Currently, SKA is completing a Risk-Based NAPL Management evaluation under TCEQ Regulatory Guidance 366/TRRP-32. Additionally, SKA is conducting continued quarterly groundwater monitoring to demonstrate NAPL plume stability in an effort to achieve regulatory closure through the TCEQ Leaking Petroleum Storage Tank (LPST) program.