Loading...
HomeMy WebLinkAbout2017-669-E SW - Draper Aden UNC LFG testing September 27, 2017 Gordon Dively, PE Solid Waste Operations Manager Orange County Solid Waste Management PO Box 17177 Chapel Hill, NC 27516-7177 Re:UNC–Chapel Hill LFG toEnergy Project Proposal for Evaluation DAA #R00592-203 Dear Mr. Dively: Draper Aden Associatesappreciates the opportunity to provide the following proposal to Orange County Solid Waste Management for the evaluation of the UNC –Chapel Hill Landfill Gas (LFG) to Energy System at the Orange County MSW Landfill, Permit No. 68-01. Primarily, the evaluation will consider options for removing water from the existing gas wells with the intention of increasing the rate of LFG collection. 1.0INTRODUCTION The UNC –Chapel Hill LFG to Energy Project (System) was initially installed and started up in the landfill in 2012 and was expanded in 2013 during the final closure of the south landfill. The system generally consist of vertical gas wells connected viaHDPE gas headers to a blower/pretreatment system. The LFG is then piped via an underground header to a 1 MW Jenbacher engine generator for the production of electrical power. The typical LFG flow rate required to run the engine is about 300 scfm. Excess gas is directed to an on-site enclosed flare where it is burned. The system was installed by and is owned and operated by UNC –Chapel Hill. The County has been informed that recent operations have determined that the supply of LFG from the landfill has been dropping resulting in not enough flow to both run the engine and keep the flare burning. The County has recently been informed that this decrease in flow is most probably due to most if not all of the wells in the south landfill being full of water; thereby blocking the flow of LFG into the well. Although the County does not own and operate the system, the County had requested that Draper Aden Associatesevaluate this situation and provide alternatives and recommendations for dewatering the wells, or other actions, that have the potential to increase the available LFG flow to the engine/flare. The following discussion presents a scope description and a not-to-exceed fee proposal for the work necessary to evaluate the System and to provide recommendations. Work will be conducted in accordance with this proposal and the existing contract between Orange County, hereinafter referenced as "County", and Draper Aden Associates, hereinafter referenced as "Engineer". DocuSign Envelope ID: 61713D3D-3E4A-490F-ADF3-8CF62BA793F2 Mr. Gordon Dively, PE September 26, 2017 Page 2 of 3 2.0BASE SCOPE OF SERVICES The Engineer will develop and evaluate alternatives for efficiently and effectively removing the water from the gas wells in the south landfill in order to increase the supply of LFG to the System’s engine/flare. The evaluation will include the following: x Site visit (already completed) to examine the landfill and discuss the background and issues with County staff. x Review of System as-builts and recent operating and monitoring data. x Development and evaluation of dewatering alternatives. x Drafting a letter report to present findings, possible alternatives and recommendations. x Submittal of the draft report to the County; followed up by a conference call, if needed. x Incorporation of the County’s comments and submittal of the final report. 3.0DELIVERABLES The Engineer shall provide a draft letter report to the County for comment and a final report upon incorporation of the County’s comments. Both reports will be provided electronically. The draft report will be submitted to the County within 30 days of authorization to proceed. 4.0EXCLUSIONS Services not expressly set forth in writing in this proposed scope, or signed attachments to this proposal can be performed as an additional service on a time and materials basis. Such additional services may include: x Additional site visit(s) with County and/or UNC personnel as requested to discuss the various options. x A detailed evaluation of the operation/condition of the LFG collection system; including well field monitoring. However, if the Engineer discoverspotential issues while reviewing operational and monitoring data provided by the County, the Engineer will provide a discussion on the issues either in the report or separately. Cost estimates for the various dewatering alternatives will not be provided.Relative costs will be discussed. 5.0ASSUMPTIONS/CONDITIONS The Scope of Services presented in Section 2.0 is based upon the County providing the following information: x As-built of the System (already provided). x Recent operation data in spreadsheet form. x The most recent month of well field monitoring data. x Recent well sounding data (if available). DocuSign Envelope ID: 61713D3D-3E4A-490F-ADF3-8CF62BA793F2 Mr. Gordon Dively, PE September 26, 2017 Page 3 of 3 6.0COMPENSATION The actual cost of providing the services described above will be based upon time expended and materials consumed. The County will not be invoiced for time not expended or material not utilized. Invoices are issued monthly and are due upon receipt. Standard DAA billing rates shall be used for billing purposes. Depending upon the duration of the project and the contract date, the unit rates used to prepare this estimate may be modified. Prior to any changes in the unit rates, the County will be notified and the modifications will be approved. The estimated not-to-exceed fee for the work is $6,000. We appreciate the opportunity to present this proposal to the County and look forward to working on this task with you. If you have any questions, please contact us. Sincerely, DRAPER ADEN ASSOCIATES C. Tyrus Clayton, Jr., PE Senior Project Manager AUTHORIZATION TO PROCEED ______________________________________ ________________ Orange County Solid Waste Management date THIS INSTRUMENT HAS BEEN PRE-AUDITED IN THE MANNER REQUIRED BY THE LOCAL GOVERNMENT BUDGET AND FISCAL CONTROL ACT: ______________________________________ ________________ Office of the Chief Financial Officer date THIS SCOPE OF WORK IS SUBMITTED PURSUANT TO THE TERMS OF THE AGREEMENT DATED FEBRUARY 22, 2017 BETWEEN DRAPER ADEN ASSOCIATES AND ORANGE COUNTY. __________________________________ ________________ Draper Aden Associates date DocuSign Envelope ID: 61713D3D-3E4A-490F-ADF3-8CF62BA793F2