Case Study: Feasibility Study for Mercury-Impacted Soil & Groundwater

Client: Former Georgia-Pacific Chlor / Alkali Facility Location: Bellingham, WA Contact for environmental projects: Doug Hillman

Project Background & Challenges

For more than 20 years, Georgia-Pacific operated a chlor/alkali facility adjacent to Bellingham Bay. Previous environmental investigations showed elevated concentrations of mercury in near-surface soils and shallow groundwater. Under terms of a MTCA Agreed Order, Ecology approved a previous soil assessment to complete the remedial investigation, with two additional requirements: a supplemental groundwater characterization and a revised assessment of remedial alternatives as part of an updated feasibility study (FS).

Solution

Under the Agreed Order, Aspect Consulting and Anchor Environmental completed the FS on an expedited schedule. Using information about natural groundwater quality and aquifer yield, we eliminated the need for drinking-water-based cleanup levels by demonstrating the highest beneficial use of shallow groundwater: discharging to Bellingham Bay. The FS interprets complex mercury geochemistry under current oxidation-reduction and pH conditions in groundwater; it also evaluates alternatives for neutralizing pH to reduce mercury mobility. Although the site is currently used for industrial purposes, we presented soil cleanup levels for a range of prospective future land uses. The FS also included a preliminary evaluation of cleanup to achieve unrestricted site use.