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5 <br /> MEMOR A N D U M <br /> MWH Americas,Inc. <br /> IV1 <br /> H 2353130th Avenue N.E., Suite 200 <br /> Bellevue,WA 98005 <br /> (425)881-1100 Fax:(425)881-8937 <br /> To: Souheil Nasr, Project Manager Date: April 22,2005 <br /> Prepared: Jay Cooke, Project Engineer Subject: Replacement of Water Transmission <br /> Lines 2 and 3—Phase 6& 7 Project <br /> Reviewed: Greg Harris, Project Manager Assessment of Bidder's Price Proposals <br /> INTRODUCTION <br /> The City received bid proposals for the Replacement of Water Transmission Lines 2 and 3 — <br /> Phase 6 & 7 Project on April 12, 2005 from four contractors. The subtotal bid price (without <br /> state sales tax) for the combined Phase 6 and 7 Project ranged from $21.36 to $22.58 million. <br /> The engineer's opinion of probable cost for the combined Phase 6 and 7 project was estimated to <br /> be $14.81 million. This memorandum was prepared to briefly describe the key construction <br /> aspects of the project and summarize the apparent major cost differences between the bid <br /> proposals received and the engineer's opinion of probable cost. <br /> PROJECT DESCRIPTION <br /> The Phase 6 project consists of replacing existing Pipelines No. 2 and 3 with new pile supported <br /> steel pipelines (48-inch diameter) approximately 3,850 lineal feet in length located immediately <br /> north of the existing alignment between Home Acres Road and the Snohomish River. The <br /> alignment is located within wetlands that are tidally influenced. Accordingly, construction <br /> access is limited which impacts the overall cost and schedule for the project. In our design <br /> approach, construction of the pile bents and pipelines was assumed to be based on accessing <br /> construction equipment on a temporary elevated work platform supported directly over the <br /> permanent steel piles. This method dramatically reduces the impacts to the wetland and was the <br /> concept used to obtain permit approvals from regulatory agencies. Construction access for <br /> bringing in all personnel, equipment, materials, and supplies is limited to either end of the long <br /> temporary access platform. In the Construction Documents, the contractor's approach for <br /> construction access and the actual design of the temporary work platform was left for the <br /> contractor to complete, since the design would be based on the equipment selected by the <br /> individual contractor. MWH designed the permanent pile bents to support a temporary access <br /> platform based on a 150-ton crane. <br /> The Phase 7 project consists of replacing existing Pipeline No. 3 with a new pile supported steel <br /> pipeline (48-inch diameter) approximately 3,820 lineal feet in length to be located within the <br /> existing alignment between Home Acres Road and Ebey Slough. Installation of the piles, bents <br /> and pipeline is based on accessing construction equipment from the existing at-grade road (20th <br /> MWH—TECHNICAL MEMORANDUM Page 1 TRANSMISSION LINES 2&3—PHASE 6&7 <br /> APRIL 22,2005 ASSESSMENT OF BIDDER'S PRICE PROPOSALS <br /> 13 <br />