BN LIVINGSTON RAILYARD
WET provides professional services to the Livingston Restoration Group (LRG) comprised of private individuals and the City of Livingston for remediation of the BN Livingston Railyard CECRA Facility in Livingston, Montana. On behalf of the LRG, WET provides oversight of facility activities and works in conjunction with BNSF Railway Company and its consultants to meet the requirements of the MTDEQ to remediate the historical rail yard. Solvents (PCE and TCE), and petroleum hydrocarbons released through historical operations have impacted alluvial soils and groundwater. PCE and TCE have migrated through the alluvium into the underlying bedrock thereby contaminating both shallow alluvium and alluvial groundwater, as well as the underlying fractured sedimentary bedrock aquifer.
Numerous consultants and remediation contractors have been under contract at the BN Livingston Facility over the past 30 years. Over the course of remedial efforts at the facility, recovery of petroleum and remediation of alluvial soils and groundwater for petroleum sources are just now being completed. Remedial efforts for the PCE plume were generally unaddressed until 2005 and lacked full delineation by 2012. Since WET has joined the efforts to address the PCE contamination, the pace of remedial activities has improved remarkably. WET initiated a decision tree process to the negotiations between MDEQ and BNSF which has improved the pace of decision making, thereby improving the pace of cleanup, and reducing overall project costs.
Since joining the effort to remediate the facility, WET has designed, installed, and continues to operate and maintain a large groundwater air sparge remediation system to strip dissolved phase PCE and TCE from alluvial groundwater and control its migration to sensitive receptors downgradient of the facility. In addition, WET was instrumental in characterizing localized groundwater flow paths in bedrock and alluvium, allowing for improved monitoring networks and characterization of the bedrock/alluvium interaction to assist in remedial design. Finally, WET has conducted pilot tests for in-situ treatment of PCE in the fractured bedrock system with the objective of selecting a treatment technology to remediate the bedrock aquifer. Pilot testing has included in-situ chemical oxidation testing and enhanced bioremediation testing. WET designed and implemented control systems to allow the injection of test solutions to focused zones within the upper bedrock unit, while limiting the migration of the injectate and groundwater contaminants to the overlying alluvium. Results of bioremediation testing have proven the potential to reduce PCE, via reductive dechlorination, to its daughter components and eventually non-toxic residual components.