Follow up on Port of Bellingham Disproportionate Cost Analysis

I previously posted a modified chart used by the Port of Bellingham for costs of the cleanup alternatives bellingham-bay-cleanup. In that post I noted that if additional analysis or information indicated my adjustments were substantially off the mark, I would modify my modifications. This effort was to do a quick Disproportionate Cost Analysis was in response to the Port and Department of Ecology's so far declining to do the analysis at least officially. I did receive some comments from a Port official that pointed out that the cost for dealing with the dioxin tainted sediments would be increased for not just the preferred alternatives. That comment is correct so here is my adjusted modified chart with an explanation below.  

Amended cleanup showing dioxin tainted sediment dredging areas

The volume of sediment in Area 1A and 1B (outer waterway) is 113,000 cubic yards. This new cost will need to be added to Alternatives 5 through 8 equally. I do not think the added cost to Alternative 4 will be as high as the material would not require the effort of burial beneath the marina but simply used as additional fill in the ASB. An assumption but I will assume the added cost to alternative 4 is $5 million versus $50. There will be no impact to costs of alternatives 1 through 3 as Puget Sound Disposal was never contemplated in these alternatives.

Area 5B (ASB shoulder) will impact alternatives 3 through 7. For 3 and 4 the impact will be very modest as both 3 and 4 can simply use the material as fill in the ASB. Alternative 8 is not impacted as this area was proposed for dredging and landfill disposal already so the increase to Alternative 8 will be less than the assumed (for now) $50 million increase.

It should be noted that there are other sites that require dredging that are not part of this cleanup. The Port is proposing dredging part of the existing marina and these sediments contain dioxins as well at levels that exceed standards for Puget Sound disposal and the levels even exceed soil cleanup levels for unrestricted use on upland property. The Port is proposing placing that sediment as a cover over an existing municipal garbage landfill area along the south shore of the aerial image above as a means of controlling water infiltration into the garbage material. Other work on the landfill will be required at some future date.