Waste and Underground Tank Management Bureau

Calumet Montana Refining LLC
Great Falls, Montana


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Calumet Montana Refining, LLC (CMR) owns and operates a petroleum refinery located at 1900 10th Street N.E., Great Falls, Montana.  The refinery is bordered on the south by the Missouri River, and by Smelter Avenue on the north.  The topography generally slopes to the south towards the Missouri River.

The petroleum refinery began operations in 1922.  The refinery produces approximately 25,000 barrels per day of petroleum products. 

CMR operated a land treatment unit (LTU) at the refinery from 1979 to 1985.  The LTU was used to treat hazardous and non-hazardous refinery wastes.  The LTU was considered a regulated unit under the Montana Hazardous Waste Act and the Environmental Protection Agency’s Resource Conservation and Recovery Act (RCRA).  CMR was required to obtain a hazardous waste permit. 

On September 22, 1995, the facility’s hazardous waste permit was issued by Montana’s Department of Environmental Quality (DEQ) and the Environmental Protection Agency (EPA).   The permit included requirements to address post-closure care of the LTU and facility-wide corrective action.  Facility-wide corrective action is the terminology used for site-wide cleanup of soil and water contamination. 

On August 21, 2012, DEQ approved completion of the post-closure care of the LTU.  The legal mechanism allowing DEQ to oversee cleanup of the site was changed to a Corrective Action Order on Consent (Order).  CMR’s hazardous waste permit was terminated when the Order was issued.



CMR is required to clean up contaminated soil and groundwater at the refinery.  Specific areas have been identified as having contaminated soil and/or groundwater.  These areas are called areas of concern (AOCs) or solid waste management units (SWMUs). The LTU is considered a closed SWMU.

Investigation and cleanup activities have been ongoing at the refinery since the 1990s.  Important milestones include:

  • Current Conditions Report (CCR):  The CCR was approved in a letter dated August 28, 1998.  The CCR is a report describing, to the extent known, the refinery’s current environmental setting, waste management activities, and previous remedial investigations.  The information in the CCR is used to help guide the RCRA Facility Investigation.
  • RCRA Facility Investigation (RFI):  The RFI is used to determine the nature, concentration, rate, and extent of migration of any release of hazardous waste or hazardous constituents at or from the refinery that might pose an unacceptable risk to human health or the environment.  CMR has submitted multiple RFI work plans and reports.
  • Facility-Wide Groundwater Monitoring:  On January 16, 2019, DEQ approved a site-wide groundwater monitoring work plan.  CMR is monitoring new and existing wells to better understand contamination at the site. 
  • Interim Measures (IM): Interim measures are actions taken to respond to immediate threats to human health or the environment. Interim or stabilization measures may be taken at any time in the corrective action process.   Interim measures have occurred at the following AOCs and SWMUs:
    • Gasoline and Light Oil Loading Rack

      The Gasoline and Light Oil Loading Rack, a truck loading rack, is located on the east side of 10th Street NE, east of the refinery’s process units and storage tanks.  In 1995 and 2001, releases of Non-Aqueous Phase Liquid (NAPL), i.e., petroleum contamination, occurred and impacted the Missouri River.  In response, CMR installed recovery trenches south of the truck loading rack. 

      In September 2016, Black Eagle Water and Sewer Board discovered vapors in the sanitary sewer.  DEQ determined the source was petroleum contamination coming from a source at CMR.  In December 2016, the Black Eagle sanitary sewer was rerouted, bypassing the impacted length of sewer. The new line connects to the City of Great Falls’ sewer line at River Road. 

      CMR has conducted additional investigations and began recovering NAPL associated with releases from the truck loading rack.  On July 19, 2019, DEQ approved additional interim measures to address NAPL and contaminated groundwater.  The interim measures include biosparging with NAPL recovery in the source area, and air sparging and soil vapor extraction to address groundwater contamination downgradient of the truck loading rack.
    • In 2013, DEQ required CMR to address contaminated soil at numerous contaminated areas of the refinery.  CMR excavated a substantial amount of contaminated soil, under interim measures, at the following areas of the refinery:
      • TEL Building Area Stained Soil
      • Staining Around Tanks 17, 52, 53, and 54
      • Stained Area East of Well DH-1
      • Tank 50 Stained Area
      • Tank 115 and 117 Stained Area and Sump
      • Lead Pit
      • Doctor Treatment Area
      • Tank 48 Spill Area
      • Past Leaded Sludge Oxidation Area South of Tank 52
    • Old Ponded Area

      Solid waste and some contaminated soil have been removed from the Old Ponded Area.  A risk assessment is currently being implemented to assist in determining additional remedial activities that may be necessary to address remaining soil and groundwater contamination.
    • Storm Sewer Release July 2017

      In 2017, a sheen was observed from the outfall of a storm water pipe that crosses CMR’s property.  CMR does not discharge storm water into the pipe.  An investigation determined a leaking underground pipe was causing intrusion of subsurface NAPL into the storm sewer pipe.  CMR rerouted the pipe to above-ground and implemented NAPL recovery.   The storm sewer was lined with a cured in-place pipe to prevent additional intrusion of NAPL.
    • After CMR conducted investigative work, DEQ determined that under current industrial use of the site no further corrective action is required at these areas:
      • Aeration Pond
      • Oxidation Pond
      • Tank 112 Dump Site
      • Land Treatment Unit


DEQ and CMR will continue to work to determine the path forward for site clean-up.  DEQ anticipates the following activities over the next several years:

  • Approving interim measures at the West Rail Loading Rack and the East Rail Loading Rack;
  • Requiring an updated facility-wide RFI Work Plan and Risk Assessment Work Plan;
  • Continuing to review ongoing facility-wide groundwater monitoring; and
  • Reviewing the effectiveness of installed interim measures at the Gasoline and Light Oil Loading Rack.   



DEQ Contact: 
Denise A. Kirkpatrick, Hazardous Waste Specialist
Montana Department of Environmental Quality
Waste and Underground Tank Management Bureau
P.O. Box 200901
Helena, Montana 59620-0901
e-mail: dkirkpatrick@mt.gov