Montana Pole and Treating Plant Superfund Site

 CAMU Construction  ______________________________________  Water Treatment Plant 

 Surface Water ____________________________________________  Groundwater 

Construction on the southside of the Montana Pole and Treating Plant site (Pole Plant) started in the fall of 2021. This spring, construction is focused on removing soils in the land treatment unit (LTU) and placing them in a corrective action management unit (CAMU aka repository). Contaminated soils in the LTU will be moved to the CAMU, which will serve as a permanent home, and allow the site to be redeveloped on the southside.  For the past 24 years the LTU served to treat the site soils contaminated with pentachlorophenol (PCP), dioxins and polyaromatic hydrocarbons (PAHs). Additional site soils not meeting the cleanup levels prescribed in the record of decision (ROD) or explanation of significant difference (ESD) for Montana Pole will also be placed in the CAMU. After construction is complete, the 27 acres around the 9 acre CAMU will be ready for recreational or industrial/commercial redevelopment.  

Follow along with the construction using the dashboards below and see real-time sampling results and track the progress. The site also contains a water treatment plant that is operating as intended. To view recent or historical data on the site and the water treatment plant, click through the dashboards below. Follow along with the construction using the CAMU Construction dashboard below and see real-time progress as contaminated soils are placed in the CAMU. This site also contains other dashboards that may be of interest.

·   The Water Treatment Plant dashboard shows weekly monitoring results for the treated contaminated water discharging to Silver Bow Creek as well as the groundwater contamination plume and how it is shrinking over time.

·   The Surface Water dashboard provides PCP sampling results during the first quarter (winter) semi-annual sampling event and dioxin/PCP sampling results for the third quarter (summer) annual sampling event.

·   The Groundwater dashboard provides PCP sampling results for each well during the first quarter (winter) semi-annual sampling event and dioxin/PCP sampling results for the third quarter (summer) annual sampling event. Groundwater elevations are also accessible in the link hydrograph for each well.

To view recent or historical data on the site and the water treatment plant, click through the dashboards below

Have a question on how to use the dashboard? Give us a call at 406-444-6360.

The Pole Plant is located on the western edge of Butte, Montana. A former wood-treating facility operated on site from 1946 to 1984. During this time, the Pole Plant used a solution of PCP mixed with PAHs (oil and/or diesel) 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 this mixture 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 PCP, dioxin, and PAHs.

The Pole Plant’s long-term remedy included constructing the LTU and 13 soil staging and pre-treatment piles; 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; removing treated soil from the LTU and placing it back in the area it was originally excavated; water treatment plant, surface water, storm water, and groundwater monitoring; and institutional controls. These remedy components are reviewed every five years to ensure that they are protective of public health and the environment, and are functioning as intended by the remedy decision documents.

Project documents and reports are available on the Montana DEQ website  here .

1983 - A complaint was filed by a local citizen concerning oil seeping into Silver Bow Creek near the site; MDHES investigated the complaint and discovered environmental contamination.

1985 - The EPA Emergency Response Branch began a removal action on the site to minimize impacts to Silver Bow Creek.

1985 - 1993 - Groundwater collected and treated on site.

1987 - The site was added to the National Priorities List (NPL) and the Atlantic Richfield Company (ARCO) was named as a Potentially Responsible Party (PRP).

1990 - ARCO began the  Remedial Investigation  and  Feasibility Study  (RI/FS) at the site.

1992 - EPA conducted an additional removal action to control and recover Light Non-Aqueous Liquid (LNAPL – floating oil) on impacted groundwater that was identified during the RI.

1993 - Contaminated groundwater began to undergo continuous pump and treatment at the Water Treatment Plant (WTP).  Record of Decision (ROD)  was finalized on September 22, 1993.

1996 - 1997 - The Land Treatment Unit (LTU) and 13 soil staging pre-treatment piles, the WTP, and two contaminated groundwater recovery trenches were constructed.

1998 - 1999 - Both hazardous and non-hazardous waste debris that had remained at the site were removed and disposed of according to all federal environmental requirements.

1993 - ongoing - Contaminated groundwater is collected and treated at the WTP.

1997 - ongoing - Biological treatment of contaminated soil in the LTU occurred. LTU surface soil lifts that were remediated to below soil cleanup levels specified in the ROD (exception: dioxins) were off-loaded.

2012 - Based on findings in the third Five-Year Review, contaminated soil was removed near utility poles located north of the NCRT.

2015 - BSB WWTP dewatering continued. BSB began planning for the future use of the south side of the Montana Pole site as they will determine eventual reuse. Final LTU offload engineering planning began.

2017 - LTU Offload Investigation was completed.

2019 - Operation and Maintenance Construction including removal and disposal of the LTU irrigation system and removal of buildings on the south side of the Montana Pole site.

2021 - In March, Montana DEQ released the final  Explanation of Significant Differences  (ESD) for Montana Pole. The ESD proposes changes to the original cleanup plan to make the site more protective of human health and the environment. Now that the ESD is complete and approved by the Environmental Protection Agency (EPA), construction can begin on the final cleanup for the south side of the site allowing for future redevelopment.

The current configuration of the Water Treatment Plant (WTP) has been in operation since the near highway and near creek recovery trenches (NHRT and NCRT respectively) were installed in 1996. Water from the NHRT and NCRT is first pumped directly to a groundwater holding tank, and then through the granulated activated carbon (GAC) treatment system.  Treated effluent is discharged to Silver Bow Creek.

WTP performance is evaluated weekly with water samples collected from WTP influent and effluent sample locations to determine the mass of pentachlorophenol removed by the water treatment plant.  Click here  to view the Montana Pole Water Treatment Plant performance graph or  here  for an annual summary table.

The MPTP ROD established a pentachlorophenol screening level of 1 microgram per liter (μg/L) for WTP discharge to surface water. Additional water samples are collected monthly from the NCRT and NHRT effluent to evaluate recovery trench performance capturing the groundwater pentachlorophenol plume. Analytical results for the WTP can be viewed on the dashboard below.

Surface water monitoring is completed per the Groundwater Management Plan (GWMP) during the first quarter (semi-annual sampling event) and third quarter (annual sampling event).   

Groundwater monitoring is completed per the Groundwater Management Plan (GWMP) during the first quarter (semi-annual sampling event) and third quarter (annual sampling event). Groundwater monitoring is completed to monitor effectiveness of groundwater collection and treatment at the Site.  

The Montana Pole Explanation of Significant Difference (ESD) established soil cleanup levels which were more protective than cleanup levels in the Record of Decision (ROD). All soils exceeding the new soil cleanup levels will be located on Montana Pole property in a landfill called a Corrective Action Management Unit (CAMU). Below is an interactive CAMU Construction Dashboard which tracks the progress of moving contaminated soil to the CAMU. Construction will start on the southside of the Montana Pole site later this year to place soils in a treated soils unit, called a CAMU. Remediation of PCPs and PAHs has already occurred through previous cleanup work. Dioxins in the soil, however, were not fully eliminated through treatment. Soils containing dioxins will be placed in a treated soils unit (CAMU) to protect human health and the environment, allowing for redevelopment.