Collaborative efforts to clean up an old lumber mill has paid off for shellfish in Port Gamble Bay.

The Port Gamble S’Klallam Tribe and Pope Resources made sure the removal of nearly 8,600 pilings and 110,000 cubic yards of wood waste and sediment from the former Port Gamble Mill site had minimal effects on shellfish in the bay.

“It was important to us that this work be done in a good way, not only for the tribe but for everyone who uses these beaches,” said Jeromy Sullivan, the Port Gamble S’Klallam Tribe chairman.

The tribe worked with the state departments of Ecology, Health, and Fish and Wildlife, environmental engineering firm Anchor QEA and Pope Resources, which owns the mill site, to develop a shellfish monitoring program to ensure the cleanup work was conducted in a way that protected local shellfish resources.

It was projected that chemicals would be released into the water as materials were removed but the results were not as high as expected, said Clay Patmont, project manager for Anchor QEA.

The tribe, Pope Resources and Anchor QEA monitored biotoxin and chemical concentrations in caged mussel and water samples before, during and after the project. Baseline monitoring took place from 2008-2015; in-water cleanup actions began in fall 2015 and concluded in early 2017.

Mussels are filter feeders that are used around the world as indicators of water quality and as an early indicator of shellfish quality. Mussels were brought in from Penn Cove near Whidbey Island, considered to be some of the healthiest mussels in Puget Sound.

Biotoxin testing included collecting mussel and phytoplankton samples to test for paralytic shellfish poisoning. Samples were sent to the state lab and were tested for warning signs of increased biotoxins.

For chemical concentrations, cages of mussels were deployed north and south of the mill site, as well as on three tribal beaches popular for harvesting, left for 60 days, then sent to the state lab for testing.

“The great news is that we didn’t see a significant increase in biotoxin or chemical levels in mussels, and we never had to close shellfish beds for harvesting,” Patmont said.

The tribe, Pope Resources, and Anchor QEA looked at four chemicals of concern – cadmium, PCBs, dioxins/furans and PAHs.

Overall, levels of these chemicals decreased over time as creosote pilings were removed and wood waste was removed and capped. In addition, the chemical levels didn’t spike as expected during cleanup. Patmont attributes that to few creosote pilings breaking while being removed.

After the project ended in January 2017, shellfish were sampled from the bay in April 2017, with results showing that chemical concentrations in the bay have continued to decline, well below advisory levels.

“So the shellfish recovery is on track,” Patmont said. “We didn’t think that’d happen for another five or 10 years.”

Mussels were used to help determine if shellfish quality was affected while woodwaste and creosote pilings were removed from Port Gamble Bay. Mussels are often used to test for shellfish and water quality during industrial site cleanup projects such as this one. Photo: T. Royal