Cleanup Activities. Based on previous risk evaluations, many areas of the Historic Smelter Area exceed the recommended cleanup levels of 1,200 mg/kg lead and/or 100 mg/kg arsenic. The extent of contamination based on the Phase II sampling results covers an area of approximately two (2) acres on the Historic Smelter Area Properties 11 and 14 (Property 15 has not been sampled). Sampling results indicated that: • Lead and arsenic levels in surface soils were found as high as 19,200 mg/kg and 946 mg/kg respectively. • Samples taken between 6” and 24” below ground surface found lead and arsenic levels increased to 77,100 mg/kg and 1,960 mg/kg, respectively. • In addition, the slag pile (“Black Rock”) is visibly eroding and is a source of continuing contamination at the site with lead and arsenic concentrations as high as 20,500 mg/kg and 125 mg/kg, respectively. The final VRWP cleanup plan is anticipated to consist of a combination of onsite disposal, capping in place and Activity and Use Limitations (AULs). The Historic Smelter Area has not had any motorized activity since demolition in 1922. Given that nearly 100 years have passed, we anticipate construction of temporary access and haul roads that will be demolished post-cleanup. The final remediation will include some or all of the following: • Selected mine waste and contaminated soils with contaminant concentrations above site- specific risk-based remedial action criteria would be excavated and consolidated in an onsite repository or capped in place. • The repository would be constructed in an area above lake peak water level and outside of the railroad right of way. The repository configuration could range from a simple unlined soil covered facility to a fully lined and capped facility. • Non-leachable soil and rock can be disposed of in an unlined facility; however, leachable material that fails to meet TCLP criteria may require disposal in a lined facility subject to RCRA hazardous waste standards. • Similarly, excavated material that meets TCLP criteria but is still leachable, as determined by acid-base accounting (ABA) and synthetic precipitation leaching procedure (SPLP) testing, could potentially impact surface or groundwater quality and may require disposal in a lined facility. • The remaining contaminated soils would be capped in place with a protective barrier to prevent human and ecological exposure. The cap could range from a simple 12-inch thick soil or rock cover to a fully-engineered cap with a synthetic line...
Cleanup Activities. The scope of the cleanup action will be developed using the TBA data and ABCA process, and will be presented in Final Cleanup Plan. For planning purposes, however, the following tasks have been identified as potential components of the cleanup effort. The preliminary descriptions identify the task objective(s), which has the lead for implementing, estimated cost, and milestones and deliverables. Schedule for conducting the work is provided in Section 3 of this Work Plan. Sub-Task 1 - UST & Drum Removal Objective: Remove the buried Xxxxxxxx solvent tank and partially-buried drums to mitigate surface waste materials and eliminate potential secondary sources for subsurface contamination. Task Lead: MOA shall contract with a local professional business concern to safely profile, remove, transport, and dispose the drums and tanks. Cost: An estimated $48,000 is allocated to contract services for this task, twenty percent of which shall be provided from Cost Share, all of which shall be paid from the Real Estate Department Operating Budget for this grant. No MOA personnel costs, equipment, or supplies will be necessary. Milestones and Deliverables: The first sub-task will be to determine if the UST and/or drums contain product, and to profile the vessel contents for disposal. After the profile results are received, the appropriate disposal method will be identified and a transport and disposal contractor will be identified. Deliverables will include profile analyses and waste disposal manifests.
Cleanup Activities. Estimated costs total $48,000 to remove underground storage tank and drums, and a minimum 20% ($9,600) shall be paid to the contractor by the MOA as Cost Share. Grant support = $48,000 Cost share = $ 9,600 plus $94,000 is budgeted for soils removal, shipment and treatment, an amount that may vary depending on the volume of soil to be treated and the most efficacious methods for effecting treatment. MOA shall cover a portion of this budgeted activity ($9,400) as Cost Share to be paid to the contractor, with the understanding that MOA’s support may be higher than currently estimated. Grant support = $94,000 Cost share = $ 9,400 plus $29,400 is allocated to groundwater treatment and contamination mitigation, with services also to be provided by a local professional. A minimum Cost Share contribution of $1,000 shall be provided to contractor by the MOA. Grant support = $29,400 Cost share = $ 1,000 plus
