Agenda - 05-08-2014 - 6h - Laserfiche WebLink

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I study has been completed and design work begun on the current project. As a result of the study's analysis, an additional 4,500 linear feet of gravity sewer designed to serve an expanded area and a larger, more flexible pump station design has been added to the project scope. The project concept now also includes a gravity sewer bore under the interstate to allow the single pump station to collect sewer from both north and south of the interstate. The pump station will be designed so that its capacity can be increased in phases as the flow increases in the area. It will have three pump slots installed and be designed to operate with up to three pumps, but will only have two pumps installed initially. This is similar in design to the City of Mebane's Southwest Regional pump station, to which this system will ultimately flow. The project will also take into account the infrastructure which has already been installed in the area, namely the Gravelly Hill pump station and associated sewer infrastructure currently being constructed. These sewer lines are designed to collect wastewater from not only Gravelly Hill Middle School, but also from the economic development area between the school and Buckhorn Road and north of West Ten Road. The Phase 2 extension project to take Efland Sewer flow to Mebane will maximize the use of this existing Gravelly Hill pump station, while including consideration for the time when the Gravelly Hill pump station needs to be upgraded to handle flow from the area it was designed to serve. The original design cost proposal for this project was $151,600. The revised proposal is not to exceed $393,000, which includes an expanded sewer economic area analysis for $46,000 and all engineering design, surveying and consulting to carry the project through the bid award phase. There is also an allowance included for the engineer to hire a sub - consultant for geotechnical subsurface investigation to gauge the amount of rock along proposed routes (not to exceed $20,000) and for wetland delineation (not to exceed $10,000). Though the project will be more expensive to design and build than originally anticipated, the project as it currently stands will eliminate the need for an additional pump station in the future to serve the area. It should also more effectively serve over 180 acres with gravity sewer once completed and will allow future gravity sewer extensions to serve the 250 acre area between Gravelly Hill School and Mt. Willing Road to be integrated more easily. In other words, the expanded project and design costs will better serve the area in the present and reduce the cost of both design and installation of future sewer infrastructure, in addition to efficiently transporting the wastewater from Efland to Mebane. FINANCIAL IMPACT: The original design cost proposal for this project was $151,600. The FY 2013 -18 Capital Investment Plan (CIP) included additional approved funds of $120,000 for design cost, for a current total of $271,600. The revised proposal totals $393,000. This Budget Amendment #7 -C provides for additional funds of $121,400 needed to cover the costs of the proposed amendment to the design costs. This includes an expanded sewer economic area analysis for $46,000, cost pass- through for the engineer to hire a sub - consultant for geotechnical subsurface investigation to gauge the amount of rock along proposed routes (not to exceed $20,000) and for wetland delineation (not to exceed $10,000). The total cost of the revised project is expected to be approximately $4.8 million, as opposed to a project cost estimate of $3.8 million, as included in the FY 2013 -18 CIP. This amendment to the design contract will carry the project through the design, permitting and bid /award phases. Construction supervision and contract administration services have not yet been procured or budgeted for this project. These will be handled under a separate contract to