INTERIM MEASURE REMEDIES
Interim Measure Remedy Evaluation
Calumet Montana Refinery (CMR) conducted a Truck Loading Rack Interim Measure remedy evaluation during the spring of 2019. The remedial action goals identified for the Truck Loading Rack include:
Reduction of mobile light non-aqueous phase liquid (LNAPL) from the Truck Loading Rack source area.
Mitigate dissolved phase petroleum constituents from migrating south from the Truck Loading Rack source area to the Missouri River.
Contain dissolved phase petroleum constituents present along the north side of River Road from migrating to the Missouri River.
CMR submitted the Truck Loading Rack remedy evaluation to Montana Department of Environmental Quality (MDEQ) on June 10, 2019.
Selected Interim Measure Remedies
The source and downgradient Interim Measure selected remedies address Truck Loading Rack historic petroleum release impacts.
Source Area Interim Measure remedial approach will include dual phase extraction (DPE) trench along the Truck Loading Rack's southern flank. The DPE system is intended to recover contaminant mass associated with free-phase LNAPL, to reduce the extent of LNAPL, and to stabilize the dissolved phase plume emanating from the LNAPL.
North River Road Area remedial approach will include a LNAPL recovery trench and a passive treatment trench (PTT). The LNAPL recovery trench and PTT are intended to mitigate dissolved phase groundwater impacts migrating from the Truck Loading Rack to the Missouri River.
CMR will conduct the following activities to implement the Truck Loading Rack Interim Measure remedy:
Conduct preconstruction activities such as permitting, procurement, and contracting (March 2021 - June 2021).
Install the Interim Measure remedies and conduct a 30-day remedy start-up (July 2021 - December 2021).
Initiate full time Interim Measure remedy operation, maintenance, and monitoring actions (January 2022).