by Michael Howell
The S&W Sawmill Facility (S&W Facility), located about a half-mile north of Darby, is regulated as a Comprehensive Environmental Cleanup and Responsibility Act (CECRA), or “State Superfund,” facility. Currently, investigation and cleanup are being addressed by the lead liable party, the International Paper Company (IPC), under the oversight of Montana Department of Environmental Quality (DEQ). IPC is in the feasibility study work plan (FSWP) phase of the State Superfund process, which serves as a roadmap for evaluating appropriate cleanup options.
Recently, additional groundwater and surface water sampling activities were performed to the north and east of the facility. Additional monitoring wells were installed along U.S. Highway 93 to monitor for pentachlorophenol (PCP) and dioxins/furans, the primary contaminants at the former S&W site. The additional investigations have led DEQ to require IPC to perform additional investigations of the Hatch Waste Ditch and adjacent areas.
Map shows the location of the Hatch Waste Ditch.
Investigations at the S&W Facility have determined that as contaminated groundwater travels away from the S&W Facility toward the northeast, it surfaces east of U.S. Highway 93 and the Overturf Ditch in the area designated above in the figure as the Overturf Seep area. This water moves north via a culvert to a pond on the northeast corner of the Darby Distribution property. Based on the pond’s location and the observed flow direction of groundwater from the S&W Facility, this pond likely interacts with the contaminated groundwater. Surface water from this pond overflows into the Hatch Waste Ditch and flows north for about a half-mile. DEQ has required IPC to collect surface water, sediment and soil samples on properties adjacent to the ditch.
According to DEQ Environmental Project Officer Robert Roll, that sampling has been underway for the past week. If there is water flowing in the ditch this fall, additional sampling may be conducted.
Once IPC completes the investigation activities, DEQ anticipates that IPC will be able to complete FSWP activities and progress toward completing the feasibility study portion of the State Superfund process. Once a feasibility study is complete, DEQ will prepare the Proposed Plan and identify DEQ’s preferred remedy for cleanup. The Proposed Plan will be made available for review and public comment. Upon completion of the public comment period, DEQ will evaluate comments received, make any necessary changes to the final remedy, and issue the Record of Decision (ROD). The ROD is DEQ’s final selection of the remedy for cleaning up a facility. IPC will implement the actions detailed in the ROD and will prepare documents outlining the implementation strategy and specific engineering design work needed to implement DEQ’s selected remedy.
For more information, contact DEQ Environmental Project Officer Robert Roll at (406) 444-6438 or via email at rroll@mt.gov.