R2008-158 AUTHORIZING AN ENGINEERING SERVICES AGREEMENT

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' � H , . � • ATTAC�IlV�NT A FOR TASK ORDER N0. 14 FOR CONTINUING AGREEMENT FOR ENGINEERING SERVICES Owner: City of Decatur,Illinois Engineer: Black&Veatch Corporation Project: Supplemental Water Supply Study Date: September 30, 2008 DESCRIPTION OF SCOPE OF SERVICES Back round g Owner is investigating alternatives for increasing the safe yield of its water supply to meet the projected demand of 49 mgd by 2031. Studies conducted by Owner have determined that an additional 10,000 acre-feet per year of water are required to meet the future demands. During most years this volume of water is available from Lake Decatur, but during periods of severe drought, additional sources will be required to meet the demand. In the 2007 study by Homer L. Chastain& Associates (HLC), The Water Plan for the City of Decatu�, HLC determined that approximately 2,700 acre-feet of additional storage in Lake Decatur could be obtained by constructing a new water intake at elevation 600 feet. The proposed new intake, which was conceptualized in the 2003 report by Engineer, Lake Decatur Water Quality Protection Measures — South Water Treatment Plant Intake Study, would be located approximately 1,300 feet upstream of the Highway 51 Bridge. Major components of the intake were 800 feet of underwater 60-inch HDPE pipe and 1,400 feet of land-based 60-inch tunnel that would connect to Owner's existing raw water pumping station. Engineer's estimated total cost of the project was approximately $3 million. HLC inflated the cost to 2007 and added approximately 28,000 cubic yards of dredging around the intake for a total estimated project cost of approximately$4.5 million. The Archer Daniels Midland Company (AD1V� has an agreement with the Owner to take a significant quantity of water from Lake Decatur for production purposes. ADM has prepared a proposal for potential alternative sources of water. A-1 , City of Decatur Task Order No.14 Rev.09-22-08