Superfund Information Systems: Site Profile

Superfund Site:


Cleanup Activities

On this page:

On related pages:


The Montana Pole and Treating Plant site is located on the western edge of Butte, Montana. A wood-treating facility operated on site from 1946 to 1984. During most of this period, a solution of approximately 5 percent pentachlorophenol (PCP) mixed with oil was used to preserve poles, posts and bridge timbers. Wood treating involved the application of the PCP solution to wood products in vats and pressure cylinders. Creosote was used as a wood preservative for a brief period in 1969. Site operators discharged hazardous substances from the pole-treating operations into a ditch next to the plant. The substances then flowed toward Silver Bow Creek. These activities contaminated soil, sediment, surface water and groundwater with hazardous chemicals.

Top of Page

What Has Been Done to Clean Up the Site?

The site’s long-term remedy included constructing the Land Treatment Unit (LTU) and 13 soil staging and pre-treatment piles; building an addition to the existing water treatment plant; constructing two groundwater recovery trenches; and excavating and disposing of contaminated soils in the LTU. Cleanup also included removing and disposing of hazardous and non-hazardous waste debris; installing in-place treatment systems; relocating sewer and potable water lines; groundwater monitoring; institutional controls; and removing treated soil from the LTU and placing it back on site.

EPA has conducted several five-year reviews of the site’s remedy. These reviews ensure that the remedies put in place protect public health and the environment, and function as intended by site decision documents. The most recent review concluded that response actions at the site are in accordance with the remedy selected by EPA and that the remedy continues to be protective of human health and the environment in the short term.

Top of Page

What Is the Current Site Status?

Remedy construction took place between 1996 and 2001. Additional cleanup is ongoing to address removal and disposal of the on-site soil treatment facilities.

Final cleanup for the southern portion of the site will be complete and ready for reuse by 2018. To protect people’s health, the property’s uses will be restricted so that the cleanup work is not damaged.

The northern portion, where the water treatment plant sits, will continue to be operated by DEQ. The reuse will not be determined until after the final cleanup design is complete. Water treatment will continue for at least the next 30 years.

Top of Page

Activity and Use Limitations

At this site, activity and use limitations that EPA calls institutional controls are in place. Institutional controls play an important role in site remedies because they reduce exposure to contamination by limiting land or resource use. They also guide human behavior. For instance, zoning restrictions prevent land uses – such as residential uses – that are not consistent with the level of cleanup.

For more background, see Institutional Controls.

Efforts to develop and implement permanent Institutional Controls to restrict residential use for the entire property within the fence line (and anywhere else needed) are underway but are not complete. The Atlantic Richfield Company, as required by the 1996 Consent Decree, caused deed restrictions to be placed on certain properties within the site. The deed restrictions prohibit residential development, drilling of water wells, and other specified uses. Similar deed restrictions will be placed on other properties within the site.

Top of Page

Emergency Response and Removal

Site cleanup has also included removal actions, or short-term cleanups, to address immediate threats to human health and the environment.

In July 1985, the EPA Emergency Response Branch conducted a removal action on the site to minimize impacts to Silver Bow Creek and to stabilize the site. EPA excavated approximately 6,000 cubic yards of highly contaminated soils, bagged them and placed them in storage buildings (pole barns) constructed on-site.

In June 1992, EPA conducted an additional removal action to control and recover light non-aqueous phase liquid (LNAPL) (floating oils) identified during the RI.

Removal actions included excavating and storing highly contaminated soil on site; dismantling and storing contaminated tanks, retorts, pipes and other hardware on site; and installing two groundwater interception/oil recovery systems. Additional removal actions included fencing contaminated areas and the groundwater recovery system, and controlling and recovering LNAPLs.

Top of Page