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GEOCON CONSULTANTS,INC. G E O T E C H N I C A L ■ E N V I R O N M E N T A L ■ M A T E R I A L S Project No. E8580-06-01 May 10,2011 Brian Krcelic TY Lin International 2010 Crow Canyon Place,Suite 350 South San Francisco,California 94583 Subject: CHANGE ORDER REQUEST FOR OUT-OF-SCOPE WORK ITEMS I-580/FOOTHILL INTERCHANGE IMPROVEMENT PROJECT PLEASANTON,CALIFORNIA Dear Mr. Krcelic: Geocon is requesting additional funds to cover out-of-scope work items being required by Caltrans District 4 Environmental Engineering Branch. The additional items were not anticipated or included in our original scope and fee estimate. Our original scope was to perform an aerial deposited lead (ADL) survey and included 20 soil borings and 60 soil samples for total lead analysis. In March 2011,Geocon submitted 23 proposed ADL sample locations to Caltrans and received the following comments that require a scope change: • 20 percent of all soil samples are to be analyzed for Title 22 CAM 17 metals, • additional ADL boring are needed along the eastbound offramp, • deeper soil samples are to be collected in area of retaining wall excavations,and • groundwater sampling will be necessary to address water quality concerns if groundwater will be encountered curing construction. Based on discussions with TY Lin, we understand that Retaining Wall /42 likely may be constructed on CIDH piles, which will result in groundwater being removed and discharged during construction. To address the Caltrans comments, we proposed to modify our scope to include I) analysis of CAM 17 metals for 20 percent of the samples (in lieu of total lead analysis), 2) five additional ADL borings and corresponding sample analyses, and 3) a direct-push boring for the purpose of collecting a deeper soil sample and a grab-groundwater sample. The soil and grab-groundwater samples from the direct push boring will be analyzed for CAM 17 metals,lPHg/BTEN/MTBE, TPHd/tno, and VOCs. The additional fee estimate for these scope modifications totals $5,800 and is broken down as follows: • CAM 17 metals analysis for 20 percent of soil samples=$2,550 • total lead analysis being replaced by CAM 17 metal analysis=<$300> • additional ADL borings and laboratory analysis= $1,250 • direct-push boring and laboratory analysis= $2,300 A spreadsheet showing the line item detail for the additional fee estimate is attached. 6671 &isa Street a liverm ire,CA 94550-2505 • Telephone 925 371-5900 • fax 925.371.5915