Like many working waterfronts across the country, Bellingham has undergone years of effort to clean up contamination and turn historical industrial sites into useful properties for the community. After more than a decade of study and adjacent cleanups, the former Georgia-Pacific [GP] Paper Mill cleanup site (“GP West site”), the centerpiece of Bellingham’s burgeoning Waterfront District redevelopment, is poised to deal with its biggest contamination culprit – liquid mercury.
A Plan in Place for one of Bellingham’s Trickiest Sites
There are a dozen cleanup sites within and along the shorelines of Bellingham Bay—by any measure, the 67-acre GP West site is likely the trickiest and most complex upland (adjacent to the shoreline/water) cleanup project of them all. To tackle the cleanup, the site was divided into halves. The half referred to as the Pulp and Tissue Mill Remedial Action Unit (RAU) was successfully remediated in 2016, allowing for the start of the Waterfront District build out including construction of the award-winning Waypoint Park. The other half of the site, known as the Chlor-Alkali Remedial Action Unit (RAU), is where the mercury lies, making it far more challenging to clean up.
Waypoint Park is thriving, with families and businesses returning to the waterfront. The Chlor-Alkali parcel is adjacent to this and will see marine industry expand and flourish when cleanup is complete.
Photo Credit: City of Bellingham
Now, after years of intense investigation and planning work, the Washington State Department of Ecology (Ecology) and the Port of Bellingham (Port) have finalized a Cleanup Action Plan for the Chlor-Alkali RAU.
Liquid Mercury is a Subsurface Challenge
The site’s mercury is an unwelcome residual from historical production of chlorine gas and sodium hydroxide (caustic) used to bleach pulp in the former GP mill’s papermaking process. Some of that mercury was released into the ground, as was some of the caustic manufactured in the process.
The mercury ‘culprit’ in the GP West subsurface for this historical paper mill site, where mercury was used in the paper-making process
Remediation crews supervising the excavation of 4,400 tons of contaminated soil removed from the site
Liquid mercury has the unique and unfortunate chemical properties of being both highly volatile and 13 times denser than water. The releases of the caustic in the same area increased the pH of the groundwater, which increased the mercury’s solubility and its ability to migrate in groundwater, allowing it to spread hundreds of feet from where the releases historically occurred. These factors, interspersed into the maze of foundation piles, beams, and other subsurface structures that remain from the former mill, make remediation of the Chlor-Alkali RAU a supremely challenging task. Additional details regarding the site’s contaminants and cleanup are available on Ecology’s webpage
A Milestone for Reviving the Waterfront
The complex Cleanup Action Plan includes a combination of removing some contaminated soil; chemically treating (stabilization/solidification) some soil in place to keep mercury from leaching further; treating groundwater to restore near-neutral conditions that will limit mercury mobility; capping some areas of lower-level contamination; and lots of monitoring throughout to assure the cleanup goals are met.
It will take several years to complete the plan’s tasks and bring the Chlor-Alkali RAU site back into productive use for the Port’s marine trade businesses. But for now, the Port and Ecology’s completion of the Chlor-Alkali Cleanup Action Plan is a momentous milestone to celebrate. It’s a significant piece of the puzzle to complete the recovery of this beautiful part of Bellingham’s waterfront.
For more information contact Principal Hydrogeologist Steve Germiat.