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HomeMy WebLinkAboutAgenda - 06-04-2013-13 (3)INFORMATION ITEM Memorandum To: Frank Clifton, County Manager From: Gayle Wilson, Solid Waste Director Date: May 21, 2013 Re: UNC /Orange County Landfill Gas Project Summary In March of 2009 the University of North Carolina entered into an agreement with the County of Orange on a Landfill Gas (LFG) to Energy project. The proposed project was to utilize methane gas generated at the Orange County Landfill (OCL) located on Eubanks Road for use as fuel in a LFG generator which was to be located on University property near the intersection of Martin Luther King Blvd. and Homestead Rd in Chapel Hill. The project was to be completed under two different contracts and also included the phasing of the project located on the OCL to coincide with the closure of the Municipal Solid Waste Landfill located south of Eubanks Road. Phase 1— Oranee County Landfill Phases 1 of construction of the landfill gas extraction and collection system involved installing the necessary wells, piping, and flare system package. The fastest part of the construction project was the installation of the wells, and the longest part was the installation of the gas lines. Construction of the gas transmission lines portion of the project started in November of 2010 and concluded in October 2011. The gas transmission line was installed to connect the wellheads of the completed wells to the flare /gas treatment station that was installed to the east of the south landfill near the existing sediment basin. A major part of the transmission line construction required the boring of Eubanks Road to tie the north landfill into the system. The transmission line installation also involved placing several condensate sumps along the transmission line to drain the liquids out of the system before reaching the flare station area. Twenty -one isolation valves were also installed in the system to provide a means for shutting down portions of the system while allowing others to still operate. In January 2011, Shaw Environmental installed 15 gas extraction wells in the south landfill. These wells extend down through the existing waste to within approximately 10 feet of the bottom of the landfill. The wells were constructed using six inch slotted PVC pipe and were backfilled with gravel to within 10 to 15 feet of the surface. The remaining annular space to the surface was sealed off using two different layers of pelletized bentonite that were hydrated with water and had soil placed on either side of the bentonite. Eighteen existing leachate cleanouts on the south landfill were fitted with remote wellheads that allow for the extraction of the gas while providing a way for condensate to drain back to the leachate piping. This gave the extraction system 33 locations scattered throughout the landfill to draw gas. The north landfill was also connected to the system; however wells were not required to be drill. Forty - five passive vents had already been installed on the north landfill prior to the start of this project. Those vents were converted to extraction wells by replacing the well head on the casing pipe. May 20, 2013 The flare and treatment system package were installed staring in October 2011 and commissioning of the system started in December. The flare station included the components necessary to simply collect and flare the gas at the landfill, and also allowed for the eventual connection to an offsite generator. In January 2012 the system was started up and has been online since. Phase 2 — Transmission Line and Generator Phase 2 of the project involved the construction of the main transmission line from the flare station located at the Orange County Landfill to a generator located at UNC's Carolina North. The 1,000 - kilowatt generator shipped from Austria started turning greenhouse gas into electricity to sell back to the electrical grid, and waste heat will be captured for use by the University to heat some of the initial buildings to be constructed at Carolina North. Installation of the piping from the landfill to the generator took place during most of calendar year 2012. The gas line takes a route that crosses County owned land, University owned land and other utility right of ways. The installation of the transmission line was not easy as it involved working close to existing utility corridors, and a major boring operation to install the line under a stream located within the first two hundred feet outside of the flare station. Commissioning of the generator started on January 29, 2013. On April 10, 2013 the entire project was accepted by the State Construction Office. UNC put the generator into commercial production on April 22, 2013. Phase 3 — Landfill Closure Within the next couple weeks, construction will start for installing the remaining gas wells and conveyance piping that will capture gas from the center of the south landfill. These wells were not installed previously due to the filling operations of the landfill. However, the landfill is scheduled to close at the end of June which will open the center areas for gas collection. These new wells should increase the gas supply to the system. The landfill cap will also aid in the collection of the gas. In theory, the cap will eliminate the escape of the gas through the top of the landfill, thus providing a greater percentage of the generated gas to the collection system. Economic Impacts During fiscal year 2012 -2013 from July through April, the County has received $33,394.88 in payments from UNC for the gas that has been collected and destroyed. The majority of these payments are based upon the gas being sent to the ofsite flare station. Going forward, the majority of the gas should be sent to a generator where it will be destroyed in an economically beneficial manner. Payments to the County will be based upon the agreement made at the onset of the project, and those payments increase for the gas used to generate electricity. The FY 2013/14 Solid Waste Budget estimates $110,000 in revenue for the upcoming year. Environmental Impacts The first project completed at Carolina North is meant to be a model of sustainability. The University will receive carbon credits for reducing pollution. The total emissions reduction as a result of the project is equivalent to the annual greenhouse gas emissions from 8,000 passenger vehicles. The carbon credits will help the University honor the American College and University Presidents Climate Commitment to May 20, 2013 be climate neutral by 2050. The landfill gas project is only one strategy in the 2009 Climate Action Plan to reduce UNC's carbon footprint to zero by 2050.