Loading...
HomeMy WebLinkAbout016 - EXHIBIT K - IDAHO POLE SUPERFUND SITEIDAHO POLE HISTORY AND PRESENT STATUS In 1992, the EPA selected a remedial alternative for the site in a Record of Decision (ROD) for the contaminants Pentachlorophenol, PAHs and Dioxin found in soils and groundwater. In 1993, Idaho Pole company (IPC) was required to implement remedial action for soil and groundwater. Contaminated soils from the IPC site, both north and south of the interstate, were excavated and brought back to the old plant site, and placed in an above ground, EPA approved Land Treatment Unit (LTU). Soils remained in the LTU and were treated biologically until they met the ROD cleanup standards. Once standards were met, these soils were placed back on the old manufacturing site in an area called the Treated Soils Area (TSA) (See Figure 3). A ground water pump and treat system was installed and ground water was filtered through mixed media and carbon until it met the required discharge parameters. A total of 625 million gallons of groundwater were treated with no exceedances of PCP or PAHs. IPC ceased manufacturing operations in 1998. All buildings and structures were removed except for the Log Office, a small green lunchroom, and the pump and treat building. The groundwater treatment system was shut down in 2016 with the approval of EPA and MDEQ. In January of 2020, the EPA completed partial deletion of surface and unsaturated subsurface soils from the Superfund list on 82 acres of the site. Groundwater chemistry from 1999 through 2021 demonstrates decreasing concentrations of PCP and PAHs. In 2009, PCP mass in site groundwater was 32.9 kg, in 2007 it was 2.12 kg, and in 2019 it went to 0.41kg (See Figure 2). Monitoring well sampling has gone from quarterly to semi-annual and now to annual. The old plant site was sold in 2022 and is awaiting development by Mr. Casey Tippens. Groundwater sampling is conducted at 20 monitoring wells, with most wells located on the property north of the freeway (See Figure 1). A recent sampling event was conducted in May 2025 with a ROD cleanup goal of 1 ppb. Of the 20 wells sampled, three met the cleanup standards as non-detect, the rest of the samples were all low single digit or low double digit parts per billion. Based on a Mann Kendall statistical evaluation, site monitoring well concentrations are continuing to decline, with a 99.6% confidence rate. At present, the EPA and MDEQ are evaluating the most recent groundwater report, and we anticipate the contamination concentrations to continue to decline. © 2025 Microsoft Corporation © 2025 Maxar ©CNES (2025) Distribution Airbus DS GM-8 27-A 16-A 28-B29-D 25-A 26-A26-B26-C 27-B 16-B 25-B 31-A 31-B 30-B RES-9 RES-7 RES-6 RES-5 RES-4 RES-3 RES-2 LITTLE ROCKY CREEKL ST8SGDWHGE\MEHUJLQ30,?/DQG3URMHFWV?0&)$5?GZJ??%GZJ>),*1257+0:V@ 1IDAHO POLE COMPANY BOZEMAN, MONTANA IDAHO POLE COMPANY NORTHERN MONITORING WELLS FIGURENORTHSCALE 0 (In Feet)500 CONTROLLED GROUNDWATER USE AREA IDAHO POLE COMPANY SITE PROPERTY IDAHO POLE COMPANY SITE NORTHERN PARCELS LEGEND MONITORING WELL RESIDENTIAL WELL GM-8 RES-1 IDAHO POLE COMPANYBozeman, MontanaPCP Concentrations in Northern IPC WellsFIGURE201002003004005006007008009001000PCP ug/L PCP Concentrations16-A16-B25-A25-B26-A26-B26-C27-A27-B29-DGM-8 Figure 3 Treated Soils Area & Controlled Groundwater Area Idaho Pole Company Superfund Site Bozeman, Montana TSA