The City of Raleigh retained SCS Engineers to assist with the process of capital project planning for new and/or upgraded facilities and programs managed by its Solid Waste Services (SWS) Department. Specifically, SCS conducted an operational evaluation and developed preliminary Capital Improvement Plan (CIP) documentation for potential facility improvements and expansions, including the City’s Yard Waste Center (YWC).
There is potential for reviewing and addressing similar organics management operations, specifically in regards to aged stockpiles, whether such piles consist of mixed debris or just leaves. This presentation will review the findings, outline the removal plan development findings as well as other considerations made during the overall effort.
The YWC opened in 1992 and manages the over 150,000 cubic yards (CY) of material each year collected by the City curbside collection program and received from other vegetative waste generators. Organic material, primarily vegetative yard waste, leaves, storm debris, and pallets, are shredded and/or recycled into mulch and compost, both of which are made available to the general public for purchase. Historically, the facility has exported a significantly reduced portion of the total amount of material it receives. While volume and mass losses attributed to drying, processing, and incidental material losses on-site may explain a portion of this discrepancy, it is evident that significant stockpiling of material has occurred throughout the years.
The majority of stockpiled processed material has been placed in the Northwest section of the YWC in what is referred to as the “Legacy Stockpile,” which according to a 2019 estimate, is roughly 200,000 CY in size and primarily composed of degraded shredded woody and vegetative material. In addition, a smaller stockpile of significant portions has also been built up. In addition to the processed brush, significant stockpiled volumes of leaves are located in the northeast quadrant of the YWC, estimated at about 100,000 CY. These volumes are considered to be rough estimates due to the uncertainty of the base grades of the land underlying the piles and do not include a “fluff” factor applied to account for the anticipated volume expansion when the material is excavated, handled/transported, and unloaded and spread.
SCS’s involvement with the planning consisted of an operational review report and drawings showing a phased YWC site plan for infrastructure improvements that could enable the City to improve its yard waste program to eventually develop a sustainable inflow and outflow of material. Prior to implementing such a plan, the City must increase the usable area of its facility by reducing the size of the existing piles and/or transporting them to an alternative location(s) for use or disposal. It must also eliminate the piles in time for an early-2021 deadline set by the North Carolina Department of Environmental Quality (NCDEQ).
As part of the operational review and CIP phased site plan effort, SCS assisted the City by investigating various options, interviewing potential material acceptors, and reviewing the potential for using Mobile Incineration Units (MIU) to reduce the volume of material that will need to be hauled off-site. Currently, SCS is assisting the City with planning efforts to meet the NCDEQ required timeframe and is in the process of implementing a stockpile materials testing protocol.
About the Presenter:
Mr. Duckett has served as an engineering consultant for landfill, landfill gas, and sustainable materials management operations in SCS’ Richmond, Virginia’ office for five years. He is an NC State University Environmental Engineering grad and licensed Virginia PE pursuing an MBA with an eye for the intersection of engineering, business, and sustainability. His work includes project management for solid waste facilities and program planning, development, and analysis- related projects throughout the Mid-Atlantic. Mr. Duckett is a USCC member and serves on the board of the Virginia Composting Council. He is also active in SWANA (Old Dominion Chapter), SVSWMA, and ASCE.