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Congressional District # 04


EPA ID# WID039052626
Last Updated: March, 2012

Site Description

In 1921, the T. J. Moss Tie Company established a wood-preserving facility west of the Little Menomonee River. The plant preserved railroad ties, poles, and fence posts with creosote, a mixture of numerous chemical compounds, derived from coal tar. While No. 6 fuel oil was also used, no evidence of pentachlorophenol (PCP) usage was noted at the Moss-American site. Operations at a creosote plant might involve storage facilities for both creosote and fuels; a boiler used to make steam to heat the creosote and aid in application to the wood through usage of heat and pressure; unloading, storage, and transportation of incoming timbers to the creosote application facility; and subsequent storage in a drying area. After these processes were completed, the treated timbers could be shipped to customers. Potential for release of contamination exists throughout the storage, application, and drying processes. For a time, the facility discharged wastes to settling ponds that discharged to the Little Menomonee River. These discharges ceased when the plant diverted its process water discharge to the Milwaukee sanitary sewerage system. Production at the facility ceased in 1976. 

In 1987, the United States Environmental Protection Agency (U.S. EPA) conducted a remedial investigation/feasibility study (RI/FS). A RI is a study to determine the nature and extent of contamination at the site. An FS is an analysis of cleanup alternatives for the site.

After documenting the selecting cleanup action documented in the 1990 record of decision (ROD), U.S. EPA again entered into discussions with the PRPs to implement the selected cleanup action. On December 30, 1991, U.S. EPA lodged a consent decree (CD) with the Federal District Court in Milwaukee. This agreement calls for the former owner/operator to implement the remedy as set forth in the ROD. The CD was entered by the court in March 1996. Parties bound by the decree include U.S. EPA, the Wisconsin Department of Natural Resources (WDNR), and the former owner/operator, Tronox.

Site Responsibility

Under the terms of a 1996 Consent Decree, Tronox LLC (formerly Kerr-McGee LLC) agreed to perform remedial design, construction, and operation and maintenance necessary to attain cleanup decision goals.  U.S. EPA and Wisconsin DNR provide oversight of work performed by Tronox.  Tronox is a Potentially Responsible Party (PRP), a party whom the EPA has determined may be legally responsible for the site's contamination.

Threats and Contaminants

Groundwater samples showed elevated levels of volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs). Free-standing creosote or an oil sheen was observed in three monitoring well samples; similar observations were noted in eight test pits. The primary contaminants detected in the River sediments are PAHs. Contaminants that were found in the soil in the processing area and vicinity, the treated wood storage area, and the northeast and southeast landfills include components of creosote: PAHs, benzene, ethylbenzene, toluene, and xylenes (BTEX) compounds. PAHs were detected in a ditch that drains water from the site to the River. The Little Menomonee River has been affected by contaminated surface water runoff and sediments from the site. Potential health risks exist for individuals inhaling volatilized chemicals or ingesting or coming into direct contact with the contaminated sediments, soil, groundwater, or surface water. 

Cleanup Progress

Progress to date:  Construction of the final remedy at the site was completed in November 2009, with completion of sediment remediation work on the final segments of the Little Menomonee River.  EPA issued a preliminary construction completion report (PCOR) on November 25, 2009 to document that construction of the remedy components were completed.  Semiannual and annual groundwater monitoring is continuing, with the State responsible for this and other work related to operations and maintenance (O & M).  The former PRP (Tronox) no longer is responsible for continuing its responsibilities under the Consent Decree after settlement of the Chapter 11 bankruptcy case in 2010.  In July 2011, EPA completed some minor housekeeping work at the site, which included the removal of excess material (pipes, tubings, fencing, concrete barriers, etc.), excavating and off-site disposal of soil/asphalt/gravel used in road-building, and regrading of 2 soil piles and a 1/4-mile temporary access road.  This work was completed in September 2011.

Background:  Construction of the remedy was outlined in the RD/RA workplan contained in the March 1996 CD.   Based on predesign results, U.S. EPA requested that priority be given to removing the free product in the groundwater and directed the PRP to design the groundwater collection/treatment portions of the cleanup project. From 1995 to 1997, approximately 10,000 gallons of free product creosote and related wastewater were collected and removed from the site. In April 1997, U.S. EPA and WDNR determined that it would be appropriate to use an innovative in-situ funnel and gate process as a means of managing site groundwater. The in-situ approach utilized injection of air and nutrients into the groundwater to promote biological degradation of groundwater contaminants. Construction of the funnel and gate system had began in 1999 and was completed in July 2000.

In 1998, U.S. EPA, with the concurrence of WDNR, modified the selected 1990 cleanup action to allow treatment of the most highly contaminated soils via thermal desorption technique to industrial/commercial soil cleanup standards, providing the affected property owner adopted appropriate property deed restrictions. Property deed restrictions were filed in 2000, and the former owner/operator completed thermal desorption remedial design in 2000. The soil treatment work was completed in early 2002. A total of 137,000 tons of site soil underwent thermal desorption treatment.

In early 2002, remedial design plans for management of contaminated sediments in the nearby Little Menomonee River (LMR) were submitted. Five reaches of the LMR were affected, and remedial work was conducted in phases. River Reach 1 included from Brown Deer Road to Bradley Road. For most of this length, a new River channel was created slightly east or west of the existing stream channel, diverting River flow into the new channel. Most contaminated sediment from the dewatered former channel was removed. The former channel was filled in with soils excavated in creating the new channel. After design approval in August 2002, U.S. EPA conducted a public availability session in September 2002. In 2003, similar design plans were completed for River Reaches 2 and 3, which extend from Bradley Road to Good Hope Road then to Mill Road. Cleanup actions in these Reaches of the River were completed December 30, 2004. Included in this phase of River remediation was development of aquatic habitat. River sediment management for River Reaches 1,2, and 3 is completed.  Cleanup of the final segment of the river (Reach 4/5) was supposed to have started in 2009, but the PRP declared Chapter 11 bankruptcy earlier that year, which resulted in EPA taking over the remaining phases of the project. 

On September 20, 2005, the EPA completed a Five Year Review Report for the site. The review found that the remedy is functioning as intended and is expected to be protective of human health and the environment upon completion of the remedy.  The two following issues were identified in the review:  (1) a need for more efficient operation of the funnel and gate groundwater system, (2) proper evaluation and execution of all necessary site institutional controls.  U.S. EPA and Wisconsin DNR are considering a proposal from Tronox to enhance groundwater treatment capability through planting trees over a zone of the aquifer where the hydraulic gradient results in particularly slow groundwater movement.

On October 31, 2008, Tronox submitted a work plan for remediating the final reach of the Little Menomenee River (Reach 4/5), which was eventually approved on March 4, 2009.  In January 2009, Tronox declared Chapter 11 bankruptcy and informed EPA in April 2009 that it would temporarily suspend the remaining work at the site.  Subsequent to this decision by Tronox, EPA decided to finish work on Reach 4/5 using Fund monies.  On August 3, 2009, EPA began work at Reach 4/5, which was completed in November 2009.  

Property Reuse

The 88-acre site is primarily owned by the county (65%) and the railroad (35%).  There is a small sliver of property owned by Tronox on the northeast corner that is not associated with known contamination from previous wood treating operations.  In the past, there has been some interest from private parties on possibly purchasing this parcel of land from Tronox.  At this time, however, interested private parties and Tronox have not gone beyond these initial discussions. 


Remedial Project Manager, U.S. EPA
Ross Del Rosario (delrosario.rosauro@epa.gov)
(312) 886-6195

Community Involvement Coordinator, U.S. EPA
susan pastor
(312) 353-1325




Site Profile Information

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


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