Ecology Identifies Cleanup Options for Northport Waterfront
- Details
- Published: Tuesday, 20 July 2021 18:22
A picture can, indeed, tell a thousand words. The Le Roi Smelter (also known as the Northport Smelter) is shown above. It handled copper ores between 1901 and 1911, and lead ores between 1916 and 1921. What’s highlighted in the foreground is the clinker and granulated slag wastes that operation of the smelter deposited on the waterfront.
Today, this is the idyllic site of Northport City Park, boat launch and waterfront area. Beneath cobbled and soiled surfaces of these areas lay the legacy of heavy metals from the smelter. Extensive soil sampling by the Washington Department of Ecology in 2019 identified ecologic and human health cleanup needs for copper, lead and zinc. Of the 329 samples taken for each, state screening levels were exceeded 33 to 66% of the time.
In May, Ecology invited the public to comment on the draft Remedial Investigation and Feasibility Study (RI/FS). To view Ecology’s documents and webinar presentation, go to their web site via this short url: www.bit.ly/3gKbLcy
Cleanup Options
As shown in the graphic, Ecology created five investigation and cleanup areas.
Seasonal beach cleanup options are both the most challenging and complex. Sediments in this area are either exposed as a walkable floodplain surface or beneath the river’s water based on seasonally alternating river flows. These flows also affect the options to achieve cleanup. Ecology’s options (e.g., cleanup alternatives) focus on identifying the best mix of 1) excavation and replacement of existing soils, 2) capping soils with material to avoid exposure, and 3) enhancing a side channel that would permit continued flow during lower river levels. As an order of magnitude, based on the option selected between 2,100 and 2,800 truckloads would be required to remove and replace 8,500 and 11,500 cubic yards of material.
Hillside cleanup options envision doing it in a way that also creates a new public amenity for ensuring safe recreational options. As shown in the graphic, 1 foot of contaminated soil would be replaced in conjunction with building a walking trail that includes a picnic shelter, tables, and benches. This provides definition to fencing and plantings to manage and limit access to other hillside areas. This limits further excavation and replacement needs to three small areas.
The jetty cleanup envisions re-armoring by securing the toe, armoring the sides and capping the jetty itself to permit continued foot traffic along the crest.
The public dock and bay cleanup would jointly excavate and replace soils within 6 feet of the dock to improve boat access by increasing the depth of water at the bottom of the ramp by about 4.5 feet. The bay flat along the jetty would be capped with clean streambed-appropriate material.
The Bayshore area cleanup would see capping the existing surface with 1.5 feet of rounded rock and streambed appropriate material.
Cost and Timeline
The three proposed options to clean up the seasonal beaches range in cost, for feasibility study purposes, from $4.6 to 7.5 million. The estimated cost for the Jetty, Bay, Bayshore and Hillside is $600,000 and incorporated into this range.
The next steps for Ecology are to respond to public comments to the draft RI/FS, finalize the RI/FS, and complete a Cleanup Action Plan. The Cleanup Action Plan will describe the specific cleanup option chosen. There will be final public comment solicited prior to engineering design, permitting, contracting and construction.
Ecology estimates cleanup can most likely begin in 2023 or 2024 during the times when river levels are low enough for cleanup areas to be fully exposed and construction equipment can operate at and above the water line.
