Denver Federal Center Calibration Silo Removal Project What are the DFC Calibration Silos? Installed in 1981 by Bureau of Mines Support minerals industry with public domain well logging tool test facility Three underground tanks with solid granite columns of known geophysical response Silos identified as Feature 1704 in investigation documents have several other associated wells including a 1970’s vintage calibration well gallery Removal action also includes USGS wells identified as Feature 616 also involved in property transfer area Potentially valuable in the support of development of geothermal industry

Denver Federal Center Calibration Silo Removal Plan Why must the Silos be Removed? GSA transferring property on west end of DFC for redevelopment under Master Plan Program Development of the property by Denver Regional Transportation District (RTD) originally scheduled for the summer of 2009 but has been accelerated RTD West Corridor line runs through silo area and seeking occupancy for construction staging Construction standards require that developer must be able to excavate down at least 30 feet at site – this precludes abandonment of the silos What Environmental Issues Need be Addressed? Colorado Department of Public Health and Environment (CDPHE) issued an “Order on Consent” under hazardous waste rules to GSA in 1997 to assess and remediate any release of contamination on DFC site. CDPHE must approve corrective action regarding closure of Silos and wells. Sampling showed potential PAH and vinyl chloride issues to correct.

Denver Federal Center Calibration Silo Removal Plan What has been done to date? USGS and GSA Established a Coordinated Approach for the Removal Activity Additional characterization of Silos and Wells made May 2008 – verified extent of contamination USGS investigated opportunities for partnerships to preserve scientific value of engineered granite at some new laboratory installation - Coordination was made with USGS seismology and water organizations and external scientific organizations to determine any beneficial applications – dozens of federal, private and university laboratories contacted to determine applicability and interest Proposed Work Plan to treat vinyl chloride in wells and dispose of silo water – formally approved by CDPHE on July 16, 2008 USGS declared granite columns unserviceable (personal) property - Form DI-103A – alternative disposal options free to move forward USGS and GSA have jointly prepared Scope of Work for Removal – GSA prepared to issue RFP for demolition contractor to remove Silos and related wells once availability of funds is confirmed

Denver Federal Center Calibration Silo Removal Plan What needs to happen? Funding must become available – project estimate presented to CELT, Regional and National IRB since May 2008 had been $839,180 of which $146,990 already earmarked in Headquarters' Working Capital Fund Endorsement of proposed partnership with DOE’s Rocky Mountain Oil Testing Center in Casper Wyoming – anticipated budget savings of some $70,000 over original project estimate through this partnership (i.e., revised estimated cost through partnership $769,180) Proposed RFP would be performanced-based and anticipate contractors may be able to further reduce associated excavation costs with new technology Concerns About Further Delay GSA pushing for urgent action by USGS to move forward suggesting delays could encumber DFC redevelopment plans and increase overall costs to RTD and the USG and reduce cost recovery leverage of GSA in such redevelopment RTD construction material costs have increased some 30% over the last year. May be illustrative of other construction cost escalations on other projects

Denver Federal Center Calibration Silo Remediation Results Removal completed on time, under budget. Engineered stone extracted and preserved. Shipped to Casper, Wyoming USDOE Rocky Mountain Testing Center is designing testing facilities to incorporate engineered stone columns RTD made construction schedule and land is being redeveloped