Enbridge logo with trademark

South Cass Lake Program

Program Overview

Following are additional details about the site. If you would like full copies of the reports, which are on file with the LLBO DRM, contact Dianne Thompson at dthompson@lldrm.org.

  • 2001 - As part of Enbridge's proactive Detection Monitoring Program, four monitoring wells were installed at the site. Results from groundwater sampling indicated that petroleum compounds were detected in the groundwater at the site.
  • 2002 - A petroleum (heavy crude oil) leak was discovered due to a leaking flange. The flange was repaired and 304 yards of contaminated soil were removed. It was estimated that 48,000 gallons of residual crude oil remained "floating" on the water table at the top of the aquifer. View illustration. Four additional monitoring wells and 21 soil borings were drilled to define the extent of the contamination and provide an ongoing monitoring network. View diagram.
  • 2003 - Four additional monitoring wells were installed and a remedial investigation report was completed, defining the extent of the groundwater contamination plume. Groundwater monitoring and free product removal continued.
  • 2004 - A feasibility report was completed recommending a subsurface cut-off wall to isolate the oil. Groundwater monitoring and free product removal continued.
  • 2005 - Two additional monitoring wells were installed. An enhanced preliminary feasibility study was prepared re-evaluating the overall feasibility of the most recent and practical clean-up technologies available. Groundwater monitoring and free product removal continued.
  • 2006 - Groundwater monitoring and free product removal continued.
  • 2007 - Groundwater monitoring and free product removal continued. The United States Geological Society (USGS) began a research project at the site. The research is focused on the natural attenuation and biodegradation of petroleum constituents in groundwater. As part of the USGS research, 11 monitoring wells were installed specifically to monitor the natural attenuation of the dissolved groundwater plume in the down gradient direction.
  • 2008 - Groundwater monitoring and free product removal continued. The USGS prepared a Project Progress Report detailing activities conducted at the site in 2007 and 2008.
  • 2009 - Groundwater monitoring and free product removal continues. A bench scale pilot test was conducted to determine the feasibility of recovering crude oil with a belt skimmer using existing monitoring wells at the site (results are pending) 
  • 2010 - Groundwater monitoring and free product removal continues. Activities and progress from 2009 are summarized and documented in a Status Update/Groundwater Monitoring Report.
  • 2010 - The USGS published "U.S. Geological Survey Scientific Investigations Report 2010-5085: Fate and Transport of Petroleum Hydrocarbons in the Subsurface near Cass Lake, Minnesota," which details the results of the 2007 research project. Click here to access the report from the USGS.
  • 2011 - Groundwater monitoring continues. Activities and progress from 2010 are summarized and documented in a Status Update/Groundwater Monitoring Report.
  • 2012 - Groundwater monitoring continues. Activities and progress from 2011 are summarized and documented in a Status Update/Groundwater Monitoring Report.
  • 2013 - Groundwater monitoring continues. Activities and progress from 2012 are summarized and documented in a Status Update/Groundwater Monitoring Report.    

Additional Information

Remediation

Pipeline Safety

Frequently Asked Questions
Copyright 2014 Enbridge Energy Partners, L.P. All rights reserved