BELLINGHAM - The cleanup strategy planned for an old city dump at the edge of Bellingham Bay should keep pollutants out of the water and away from people, if port and state officials are correct in their assessment of the situation.
That assessment is supported by a 1,400-page analysis prepared by the port's consultants. The document summarizes the findings from extensive sampling of soil and water at the 16-acre site and adjacent tidelands, and estimates the costs and benefits of alternative cleanup strategies for making the property suitable for a new life as a city park.
It is no simple task. Among other things, the $9.1 million cleanup project will need to cover up about 100 feet of shoreline where erosion has exposed city rubbish dumped and buried there in the 1950s and 1960s. It also will need to cover and contain the accumulation of trash farther inland, sealing it off to prevent rainwater from seeping in and carrying pollutants to the surface or into the water.
During a Tuesday, Aug. 27, interview, Port of Bellingham environmental site manager Brian Gouran and Washington Department of Ecology site manager Mark Adams explained how the complex cleanup plan will work:
- A layer of clay will cover the garbage, providing one barrier to water infiltration. Some of the clay is already in place in the form of dredged material from Squalicum Harbor, and additional clay will be added.
- A layer of thick plastic will top the clay to provide a second line of defense against seeping water.
- A layer of sand will cover the plastic, to provide a pathway for rainwater to move horizontally into the bay before it touches any buried contaminants.
- Atop the sand will be a layer of topsoil for grass and trees.
At a recent port commission public hearing on waterfront redevelopment plans, some people expressed concern that any new park on the site would have to be treeless, because otherwise, tree roots could rupture the containment system and release toxins.
Gouran said that isn't so. He acknowledged that tree-planting will have to be done thoughtfully, in a way that eliminates any risk of a puncture. But there will be trees.
"There are ways to do it," Gouran said.
Adams noted that the city already has a park on top of another old landfill: Maritime Heritage Park at the mouth of Whatcom Creek.
Citizens have also expressed concerns about dioxin contamination of the marina's dredged sediments already in place under a thick white plastic cover at the site. Adams acknowledged that small amounts of dioxin have been detected, but they are barely above levels that exist elsewhere.
"Dioxins are ubiquitous in the environment," he said.
Even so, Adams insisted that the containment system for the dredged sediment and garbage would be engineered to stop any human or environmental exposure to dioxins and anything else in the sediment.
The lengthy study of the cleanup problem examined four cleanup alternatives. Three of the four provide variants on the burying-in-place approach. The study recommends one of the three, as explained above, as offering the most protection for the money.
A fourth possibility - digging up contaminants and carrying them hundreds of miles to an approved landfill for disposal - would cost about $78 million. That is more than eight times the cost of the recommended plan.
Adams said digging up the garbage would not be without environmental risk, since some of that excavation work would have to be done in the water, and there would be no way to keep some toxins from being released into the bay in the process.
Public comment on the cleanup plan is being taken as a final step before the plan becomes final. With a plan in place, engineers can get to work on a detailed strategy for doing the work. If all goes smoothly, Gouran said the cleanup work could begin in 2015 and be complete in 2016.
The draft report, known as a remedial investigation and feasibility study, is available for public review on the Ecology website, at Ecology offices in Bellingham and Bellevue, and at the Bellingham Public Library.
Written comments can be sent to Mark Adams, Ecology site manager, through Sept. 20 at firstname.lastname@example.org or 3190 160th Ave. N.E., Bellevue WA 98008-5452.