Former Armstrong World Industries Site Contamination (Lowland Operable Unit)

Historical process water discharges and stockpile/waste storage practices at this former fiberboard manufacturing plant resulted in impacts from heavy metals, dioxins/furans, and polycyclic aromatic hydrocarbons (PAHs) to the lowlands (i.e., wetland and tidal flats) surrounding the plant. GSI is characterizing and designing an interim removal action measure (IRAM) for the lowlands for DEQ, which has taken over cleanup actions at the site under its Orphan Program.

Site contamination has become distributed throughout the complex hydrogeologic and ecological setting of the lowlands. These lowlands are heavily influenced by tidal oscillations and the stage of the nearby Columbia River, creating variable chemical and ecological conditions. To further characterize conditions in the lowlands and gather data in support of a feasibility study, DEQ asked GSI to design and implement a data gaps investigation intended to expand upon earlier work. GSI planned this work in 2020 and 2021 through the development of numerous programmatic and specific work plan documents, implemented the data gaps investigation in 2022, and reported the results in 2023.

The DGI included a comprehensive multimedia investigation targeting assessment of sediment/soil, groundwater, porewater, and wood wastes throughout the lowlands. Before the lowlands could be sampled, permits were obtained through the U.S. Army Corps of Engineers and the Oregon Department of State Lands, which required a cultural resources survey and wetland delineation. Investigations have included the use of novel porewater and redox chemistry sampling techniques, sampling of upland groundwater wells, and an extensive, multifaceted sediment/soil sampling program, including completion of 62 sediment cores for more than 800 samples.

GSI is now developing an IRAM in the lowlands. This work will involve the development of a conceptual IRAM, implementation of an IRAM investigation, and development of design documents and materials for the IRAM itself. The ultimate goal of the IRAM will be to remove as much chemical and wood waste mass as possible from the site by the end of 2027 with the resources available through DEQ’s settlement fund.

GSI’s work has involved:

• Developing and implementing a data gaps investigation, which required creative thinking and novel approaches due to the nature of the work and the complex setting of the lowland area.
• Using innovative technologies and approaches to data management, such as field data collection tablets and an ArcGIS Enterprise spatial data viewer that updates in real time.
• Leading the development of an IRAM.