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CTEC Newsletter
and The Montana Pole & Treating Site The Silver
Bow Creek/ |
MONTANA POLE & TREATING SITE The Montana Pole and Treating
site is an abandoned 40-acre wood treatment facility in Butte,
Montana. From 1946 to 1983, the facility preserved utility poles,
posts and bridge timbers with pentachlorophenol (PCP). Hazardous
substances from the pole-treating operations were discharged
into a ditch next to the plant that ran towards Silver Bow Creek. About 16,000 gallons of PCP contaminated waste oil were sent to a licensed disposal facility in Utah for incineration in the 1980s. In spring 1998, forty drums of PCP contaminated sludge were shipped to Utah. The state of Montana signed an agreement with a contractor in March 1999 to dispose of all remaining site debris. BACKGROUND The ground water and soils at the Montana Pole site are contaminated with PCPs, dioxins, furans (flammable liquids from wood oils), volatile organic compounds (VOCs) and metals. The sludge also is contaminated with PCPs, dioxins and furans. PCP has been detected in Silver Bow Creek. Accidentally swallowing or having direct contact with ground water, surface water, soil or sludge can be hazardous to human health. Contaminants may enter the air naturally or during cleanup operations, presenting another potential source of exposure. The site was proposed for addition to the Environmental Protection Agency's (EPA's) Superfund National Priorities List (NPL) in June 1986. The final date of its addition to the NPL was July 1987. CLEANUP APPROACH The site is being addressed in two stages: an immediate action and a long-term remedial phase. EPA completed a cleanup action in late 1988 to halt the seepage of PCP and diesel oil into Silver Bow Creek. Contaminated soils were excavated and stored on the site, which has been fenced. Monitoring wells and oil recovery trenches have been installed. A temporary groundwater/ soil separation treatment system was put into operation to separate PCP-contaminated oil from the ground water. The treated water is pumped up gradient to infiltration galleries. In January 1990, Special Notice Letters were sent to three Potentially Responsible Parties (PRPs). A Consent Order to conduct an investigation of site contamination was negotiated with the Atlantic Richfield Company (ARCO). An additional notice letter was sent to Burlington Northern Railroad Company in October 1991. In early 1991, EPA conducted a cleanup of oil-contaminated soil, following the release of 3,000 gallons of contaminated oil from a holding tank. Approximately 21,000 gallons of polluted oil have been intercepted and are stored on the site. In the summer of 1992, EPA conducted another removal action. During this action, a plastic liner was inserted into the ground to prevent PCP contaminated fuel in the ground water from entering Silver Bow Creek. Groundwater recovery wells were installed to recover free phase PCP contaminated fuel from site ground water. A water treatment plant was built to clean contaminated ground water. After treatment, the water is discharged to Silver Bow Creek. In 1993 ARCO, a responsible party, completed site studies to determine the nature and extent of contamination. A remedy was selected in the fall of 1993. The remedy includes:
The water treatment plant is operating, and excavation of the contaminated soil is under way. FINANCIAL CONSIDERATIONS EPA sued ARCO for recovery of past removal costs in September 1991. ARCO countersued EPA contractors in October 1991. A settlement was reached in 1996. The PRPs are providing $38 million for a state led cleanup under a cash out, where the PRPs provide funding and the agencies conduct the cleanup. Through its Technical Assistance Grant (TAG) program, EPA funds a citizens' group to hire a technical expert to review EPA studies and cleanup work, and to convey the findings to the community. ENVIRONMENTAL PROGRESS EPA has taken measures to prevent further contamination of Silver Bow Creek. Additional actions were taken to remove the immediate sources of soil contamination, treat ground water and restrict access to the site. These measures have reduced the potential for exposure to hazardous substances while further cleanup activities are under way. |
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