St. Louis River Interlake/Duluth Tar Site

In 1916, Duluth Tar Company became Barrett Tar Company, which closed in about 1924.

A new tar refining operation was built in 1924 in Area E, adjacent to the Duluth Tar Company/Barrett Tar Company facility. The new facility, owned by Dominion Tar Company and American Tar Company, operated until 1948. These facilities purchased coal tar from Zenith (later Interlake), operated batch coal tar stills and manufactured tar products. The tar and chemical companies closed down by 1948, and the most recent iron plant has not operated since about 1960. 

In 1929, Zenith Furnace Company’s coking operations were relocated to Area B (the head of the current Hallett Slip 6) and the company became the Interlake Iron Company. Its water gas plant remained in Area D. Crude tar produced from coking operations at the Interlake Iron facility was sold to the tar refineries located in Area E. Other industrial byproducts were used in conjunction with re-deposited native sediment as fill to create new land, including the 59th Avenue Peninsula and the 54th Avenue Peninsula. The primary fill material is slag from on-Site pig iron operations.

Interlake Iron’s operations ceased in 1961, and the property was idle until 1966, when Hallett Dock Company (Hallett) purchased the former Interlake Iron portion of the SLRIDT site. Hallett has used the property primarily for bulk storage and handling of coal, coke, bentonite, and other industrial materials. Hallett has sold and/or leases northern portions of the SLRIDT site to other companies.

The sources of contamination in the sediments at the SLRIDT site were primarily wastewater discharges that began in the early 1900s from the water gas, coking and tar facilities formerly located on the SLRIDT site. The last operating industrial discharges from these facilities were terminated no later than 1961 when Interlake Iron shut down the last operating facility. Waste discharge areas include the Area F crescent shaped pond and Area A and E discharge pipes that drained into Stryker Bay. Area C pond and the 48 inch outfall pipe discharged into Keene Creek Bay and the southern tip of the 54th Avenue Peninsula.

The SLRIDT site is within the West Duluth neighborhood of the City of Duluth, on the north bank of the St. Louis River, approximately four river miles upstream from Lake Superior.

The SLRIDT site includes approximately 255 acres of land and river embayments, wetlands, and shipping slips. The land includes the 59th Avenue (Hallett) Peninsula, the 54th Avenue Peninsula, and is bounded on the north by the Burlington Northern right-of-way. Site features are identified on the below site map.

The aquatic portion of the SLRIDT site includes Stryker Bay (approximately 41 acres and defines the western boundary), Slip 6 (about 15 acres), and Keene Creek Bay/Slip7 (about 38 acres and defines the eastern boundary), and the St. Louis River to the south. A small portion (approximately 0.3 acres at the mouth of Slip 6 and 1.1 acres in the Minnesota Slip – aka the Federal navigation Channel) is within the waters of the State of Wisconsin.

Residents are located west of the site on the 63rd Avenue Peninsula, and to the north of the railroad tracks. According to the 2000 census, approximately 960 people live within one half mile of the site.

In 1979, MPCA staff detected PAHs in Stryker Bay sediments. PAHs are a group of carcinogenic and non-carcinogenic compounds formed during the combustion of coal, oil, gas, wood and other substances. At the SLRIDT site, PAHs are a by-product of the production of water (town) gas, high-temperature coking of coal and the distillation of crude tar. 

In 1980, MPCA staff’s analysis of samples from Stryker Bay’s surface water showed the presence of PAH compounds. In addition, in 1981 a local resident reported oil rising to the surface of Stryker Bay, which stemmed from the slow release of coal tar waste mixed in with sediments. 

In 1983, the U.S. Environmental Protection Agency (EPA) evaluated the SLRIDT site and the St. Louis River/U.S. Steel site (located on the St. Louis River approximately 4 river miles upriver from the SLRIDT site) and added them as a single site to the National Priorities List (NPL) (the federal Superfund list). The federally listed site is referred to as the St. Louis River/Interlake/U.S. Steel site. Although the two sites are listed as one on the NPL, they are listed separately on the Minnesota Permanent List of Priorities (the State superfund list) and are being investigated and cleaned up separately. 

To obtain input on community concerns about the cleanup of the SLRIDT site, the MPCA staff established a community work group to discuss the issues and complications involved with the investigation and cleanup of the site. The work group consisting of representatives from neighboring residents, local community associations, current landowners, environmental groups, Responsible Parties, city officials, MPCA officials and other interested parties group first met in March 1995.

As part of the initial SLRIDT site investigations, the MPCA staff identified four Responsible Parties, three of which have taken and/or agreed to take remedial actions for various portions of the SLRIDT site. The three Responsible Parties that have agreed to take remedial actions for the Sediments Operable Unit are:  the XIK Corporation (formerly the Interlake Corporation or “Interlake”), Honeywell Inc. (formerly AlliedSignal Inc. or “Allied”), and Domtar Inc. (Domtar) (collectively called the Companies). The fourth Responsible Party, Beazer East, Inc. (Beazer) has refused to participate. 

Further investigations revealed contamination that was categorized by the MPCA into one or more of the three operable units (OU)– Tar Seeps, Soil, and Sediments. Groundwater at the SLRIDT site is also contaminated and is being addressed under the soil and sediment operable units.

The MPCA issued Requests for Response Actions (RFRAs) in March 1991 and May 1993 to the Responsible Parties to clean up the Tar Seeps and Soil Operable Units. The Companies completed cleanup of the Tar Seeps Operable Unit in 1994, and the Soil Operable Unit in 1997. Both operable units were cleaned up to industrial land use standards. Groundwater monitoring is being addressed as part of the five year review of the Soil Operable Unit.

The Sediment Operable Unit included approximately 450,000 cubic yards of sediment that exceeded MPCA standards for contaminated sediment. The MPCA issued two RFRAs for the Sediment Operable Unit: one in March 1994 to Interlake (now XIK Corporation), and a second one in March 1996 to Beazer, Allied (now Honeywell) and Domtar.

In November 1999 the MPCA presented a Proposed Plan to the public for cleanup of the Sediment Operable Unit which was opposed by the Companies. In February 2000, the Companies and MPCA entered an agreement to reopen the Remedial Investigation/Feasibility Study (RI/FS) process, to gather information to fill data gaps, and to evaluate four cleanup alternatives: No Action; Wetland Cap; Dredging and On-Site Disposal; Dredging and Off-Site Disposal. 

Additional data collected to fill the data gaps was submitted to the MPCA in the November 27, 2002 Data Gap Report. The MPCA facilitated a two-day meeting in February 2003 to discuss the remedy implications of this new information. The meeting included representatives of the Companies and their consultants, MPCA staff, the Peer Review Team, State, federal and tribal natural resource managers, property owners, area residents, the City of Duluth, and other stakeholders. 

Using the information developed at the February 2003 meeting the Companies, the MPCA, and the DNR identified a hybrid cleanup alternative to be evaluated in the Feasibility Study. However, additional studies revealed that the capacity for storing dredged material in the original CAD in Slip 7 was overestimated, and the volume of material to be dredged was underestimated. Therefore, the Dredge/Cap Hybrid Alternative was revised to move the containment of dredged materials from Slip 7 to Slip 6. The Agreement was also amended to reflect this revision in the hybrid alternative (Amendment No. 2) and the Feasibility Study Revised Addendum 1 was developed by the Companies to evaluate the revised hybrid alternative.

In 2004 a Record of Decision (ROD) documented the dredge/capping hybrid as the remedial action, and in 2005 a Remedial Design/Response Action Plan (RD/RAP) was approved. Remedial action in the form of a pilot capping project was conducted in 2004. Further Remedial action took place from 2006 to 2011 and is documented in the Project Completion Report, 2013. In August 2013, a Long Term Monitoring and Maintenance (LTM&M) plan was approved for the Sediment OU.  The monitoring component will determine short term performance over a five year period using a tiered approach. Long term monitoring will continue as long as the contamination remains on site.

In 2013, the third Five Year Review was completed by the MPCA. It indicated that the Soils OU was not fully protective of human health, and several issues needed to be addressed. They included tar layers, and a small tar seep area, and remnant tar found in onsite soils. The Sediment OU was found to be protective in the short term; however institutional controls such as dredging restrictions are needed to ensure long term protectiveness.

Sediment (SedOU)

Documents related to the SLRIDT NRDA are available at the West Duluth Library, 5830 Grand Ave., Duluth, MN 55807.

NRDA documents:

• SRLIDT Restoration Plan and Environmental Assessment NRDA (c-s3-17b)
• Assessment Plan for the Natural Resource Damage Assessment
  • Avian Exposure and Injury Study Workplan
  • Fish Exposure and Injury Study Workplan
• Restoration projects: Grassy Point and Kingsbury Bay (DNR)

• Site map: St. Louis River/Interlake/Duluth Tar site (c-s3-17g)
• Historical photos
• 2007 Construction Photo Gallery
• Remedy Construction Activities Presentation
• Tallas Island Compensatory Mitigation Project Presentation

Site events:   

Updated annually
Last revised: April 2017

Reports

• Third Site-wide Five-year Review, 2013 (c-s3-06ag)
• Second Five Year Review, 2008
  • Second Five Year Review Attachments
• First Five Year Review, 2003
• Assessment Plan for the Natural Resource Damage Assessment

• • Avian Exposure and Injury Study Workplan
  • Fish Exposure and Injury Study Workplan

Soil/Tar Seeps Operable Unit

• Record of Decision for the Soil Operable Unit, September 1995
• Record of Decision for the Tar Seeps Operable Unit, October 1990

Sediment Operable Unit

• Long-Term Monitoring Report Year Four, 2016 - SLRIDT Project (c-s3-17f)
• Long-Term Monitoring Report Year Three, 2015 - SLRIDT Project (c-s3-17e)
• Long-Term Monitoring Report Year Two, 2014 - SLRIDT Project (c-s3-17d)
• Long-Term Monitoring Report Year One, 2013 - SLRIDT Project (c-s3-17c)
• Long Term Monitoring and Maintenance Report, December 2013
• Record of Decision for the Sediment Operable Unit, August 2004
  • Report Figures
  • Appendix 1
  • Appendix 2
  • Appendix 3
  • Appendix 4
  • Appendix 5
  • Appendix 6
  • Appendix 7
  • Appendix 8
  • Appendix 9
• Proposed Plan for the Sediment Operable Unit, April 2004
• Revised Draft Feasibility Study, December 30, 2003)

• • Revised Addendum 1 to the Feasibility Study, March 29, 2004
  • Peer Review Team Comments on the Revised Draft Feasibility Study and the Revised Addendum 1 to the Feasibility Study, April 2004
  • Revised Draft Feasibility Study Approval Letter, January 14, 2004
  • Approval and Comments Letter on the Revised Draft Feasibility Study, April 27, 2004
• Approval and Comments Letter of the November 8, 2002, with Revisions Through November 27, 2002, Draft Data Gap Report Approval Letter, MPCA, January 14, 2004
  • Part 1
  • Part 2
  • Part 3
  • Part 4
• Agreement between the Minnesota Pollution Control Agency, The Interlake Corporation, Honeywell International Inc. and Domtar Inc. Concerning the selection of the Remedy for the Sediments Operable Unit of the St. Louis River/Interlake/Duluth Tar Superfund Site, February 22, 2000
• Amendment No. 1 to the Agreement concerning the selection of the remedy for the Sediments Operable Unit, December 30, 2003
• Amendment No. 2 to the Agreement concerning the selection of the Remedy for the Sediments Operable Unit, April 27, 2004

Location of site documents and records:

Duluth MPCA
525 Lake Ave. S
Suite 400
Duluth, MN  55802
Phone: 218-723-4660
Fax: 218-723-4727

Archived list of meetings:

• June 14, 2011 – Construction Wrap Up Meeting
• November 16, 2007-Community Workgroup Meeting
• October 3, 2007-Community Workgroup Meeting
• June 13, 2007-Community Workgroup Meeting 
• March 14, 2007-Community Workgroup Meeting
• May 10, 2006 – Community Workgroup Meeting
• April 12, 2006 – Community Workgroup Meeting
• February 23, 2006 – Community Workgroup Meeting
• September 29, 2004 - Community Workgroup Meeting
• September 1, 2004 – Community Workgroup Meeting
• May 10, 2004 - Proposed Plan Public Meeting
  • MPCA Proposed Plan for the Sediment Operable Unit (Presentation)
• November 25, 2003 - MPCA Citizens’ Board Meeting to Approve Amendment No. 1 to the Agreement.
• September 11, 2003 - Community Workgroup Meeting to update community on progress
• August 12, 2003 – Workshop Meeting to Discuss Proposed Remedial Alternative Option for the Cleanup of Contaminated Sediments
• May 15, 2003 - Five-Year Review Meeting.