Document q8QEv4YL6mr9v4z3mZrxQ6qn

RN2: Dock Relocation, Cofferdam Construction. Excavation, and Disposal IS Modified RN2: Removal and Containment * k tp+ Urt '' Excavation, requiring relocation of operating barge dock, Scope Pumped extraction of contamination through use of a river followed by construction of massive cofferdam (extending 40' barge, without interrupting use of dock, through a into air above low river level to address river level change). methodology already used at site as shown in above photo, Once excavation begins, removal of covering soil ranging followed by installation of engineered interlocking sheet pile from 7 to 25 feet thick, takes place before encountering deep contamination zone Complexity Because the dock must be relocated, no remedial work can take place until a new temporary dock can be designed and built, the existing dock removed, and a temporary cofferdam installed Complex design, not just for the cofferdam and dock All of the work is done by barge, without interrupting existing operations and not requiring dock relocation construction, but also for logistics of access for excavation inside 30' deep hole and routing of 13,000 dump trucks of soil through the site and onto public roads 2 year design, with at least 3 more years until removal * At least 6 permits needed to commence removal Timing 2 month design, with immediate removal following No permits needed for removal Hypothetical 100% removal Remedy Effectiveness 100% containment after 95% removal/immobilization EPA estimated $144M total project cost Cost Effectiveness $8M total project cost 60% of the costs are actually "non-value added" work, not performing remediation $36M to build temporary dock and infrastructure $50M to relocate endangered mussels, install cofferdam, backfill the hole, and remove cofferdam 100% of it focused directly on remedy $3.2M removal through wells $3.2M installation of containment Only 40% of the total costs are spent on remediation The majority of those costs - $36M - is spent on relocating the waste soils to a landfill Sierra Club v. EPA 18cv3472 NDCA Prod 1 ED 002061 00118933-00001