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Congressional District # 02


EPA ID# MND000686071
Last Updated: November, 2011

Site Description

The Koch Refining Company/N-Ren Corp. (Koch) site is an active oil refinery and covers 1,200 acres in the Pine industrial district of Rosemount, Minnesota. The site includes the refinery and adjacent properties, owned by Koch. The Great Northern Refining Company began refining oil on this site in 1955. In 1969, the refinery was sold to Koch, which expanded refining capacity from 25,000 barrels to 160,000 barrels per day. The refinery receives crude oil by pipeline and barge; the crude oil is then refined into gasoline, jet fuel, heating oil, kerosene, diesel fuel, boiler fuel, asphalt, petroleum coke, sulfur, carbon dioxide, butane, and propane.

Product spills had been recorded in the storage tank area on the site since the early 1970s. The State of Minnesota sampled water from six private wells near the refinery and found them to be contaminated with volatile organic compounds (VOCs). A section of gasoline pipeline, running from the tank farms to the barge dock on the Mississippi River, had corroded but was replaced. This pipeline is believed to be one of the sources of groundwater and soil contamination at the site.

Drinking water for the employees on the site is obtained from deep bedrock production wells that are not contaminated. Approximately 60 people live within one mile of the refinery. About 1,600 people and a school with 2,600 students use wells within three miles of the site for drinking water. Four miles north of the site is Inver Grove Heights with a population of about 16,100 people. There is a population of about 6,800 people to the south of the site.

Site Responsibility

This site is currently being addressed through State-lead Resource Conservation and Recovery Act (RCRA), and Underground Storage Tank programs. 

Threats and Contaminants

Groundwater contaminants include VOCs, polycyclic aromatic hydrocarbons (PAHs), phenols, and lead. Soil is also contaminated with VOCs that include benzene, toluene, and xylenes as well as PAHs. 

Certain other site production equipment are managed under non-Superfund environmental statutes.  Such equipment includes flares, tanks, and lagoons used as settling ponds for "coke fines," which were particulates contaminated with polycyclic aromatic hydrocarbons related to refining operations.  Spill protection, RCRA waste management, effluent limitations for surface water discharge, and air emission controls are all environmental management matters which the operating plant continues to address.     


Cleanup Progress

The United States Environmental Protection Agency (U.S. EPA) conducted preliminary evaluations of the site conditions and determined that there were possible releases from the barge dock loading area although no immediate threat was posed to the surrounding communities or the environment.  Under state supervision, Koch conducted an investigation into the nature and extent of soil contamination in the vadose zone at the site. The vadose zone is the layer of subsurface water just above the groundwater table.  A Superfund cleanup of one portion of the site was conducted which included free product recovery wells, groundwater gradient control, and soil gas extraction, which were successfully completed.

Further studies determined that the site is a petroleum release site and the site was transferred to the Minnesota tanks and Spills Program under RCRA in 1985. The Minnesota Tanks and Spills Program conducted a pilot study to investigate the possibility of using a vacuum extraction system to further clean up the soil.  In addition, two homes east of the refinery were supplied with bottled water.  In 1985, the state entered into a consent agreement (CA) with Koch, whereby the company agreed to clean up the remainder of the site.

U.S. EPA deleted the site from the Superfund National Priorities List on June 15, 1995.



Remedial Project Manager, U.S. EPA
leah evison (evison.leah@epa.gov)
(312) 886-2064

Community Involvement Coordinator, U.S. EPA
Don De Blasio
(312) 886-4360




Site Profile Information

This profile provides you with information on EPA's cleanup progress at this Superfund site.


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