WASTE CONVERSION TECHNOLOGIES REDUCE DISPOSAL COSTS, INCREASE REVENUES
Located in the heart of North Carolina, Asheboro is home to rich economic, natural and cultural resources. Our “come as you are” attitude invites you to jump in and become part of the community – whether you’re here for an afternoon or a lifetime. With a population of approximately 25,000, Asheboro is the largest city in Randolph County and is part of the Piedmont Triad, an area that includes Greensboro, High Point and Winston-Salem.
The City of Asheboro was spending $750,000 – $1,000,000 on an annual basis to collect, haul, and dispose of Municipal Solid Waste (MSW). This expense represents a large portion of the Town’s operations, and with the threat of rising fuel costs and tipping fees, the City desired a plan to more cost-effectively manage its solid waste through innovative approaches. Alternately, the City would be forced to pass along increased costs to its citizens for solid waste management, and potentially reduce the extent of service offered.
|Item||Tons Collected (FY2011)||Average Cost*|
|Residential Solid Waste||10,035.41||$ 491,967.81|
|Commercial Solid Waste||3,902.65||$ 191,320.35|
|Curbside Recycling||1,566.51||$ 76,795.32|
|Drop Site Collection||524.96|
|C&D (construction, demolition and building materials||1,207.95|
|Other (stumps, concrete, oil, etc.)||366.19||$ 17,951.80|
|Total Residential MSW Collected:||11,601.92||$ 568,763.13|
|Total MSW Tonnage Managed:||19,112.44|
The City of Asheboro commissioned Cavanaugh to evaluate alternatives and opportunities for solid waste management, and present its findings and recommendations to the City as a Feasibility Study report. Cavanaugh’s efforts provided strategies to help the City of Asheboro more cost-effectively manage its solid waste, and provided recommendations for implementing alternate revenue enhancements that derive value from a portion of the wastes they manage. After review of the existing practices for collection municipal solid waste (MSW), recycling, and solid waste disposal, the following conclusions were surmised:
- The Department of Sanitation has implemented strategies to increase revenue by selling the recyclables and reducing costs through reduced tipping fees (tonnage reduction) by the same. The City is selling the separate recycle streams obtained from its Drop Sites to various materials handlers at market rates. The City recently purchased a former contract hauler’s equipment, thus reducing the hauling costs through elimination of the transportation taxes on the fuel used by the contract hauler. The City also now maintains the truck fleet in-house, which allows the City to avoid paying the higher fees associated with commercial repair shops.
- An opportunity exists for the City of Asheboro to upgrade its current Anaerobic Digesters at the WWTP to produce more biogas. This biogas can be used to make energy consumed at the WWTP, reducing electrical costs for the City. This could be accomplished by using additional equipment for shredding and size reduction of the organic portion of the MSW, then feeding these organics into the existing Anaerobic Digesters at the WWTP, which are operating at less than 50% capacity. These biodegradable organic solid wastes would include food waste from restaurants, grocery stores, cafeterias, and public schools. A potential also exists to expand the City’s existing curbside recycling program to include an additional container for waste organics.
- A Composting Facility for disposal of yard wastes and anaerobically digested sludge from the wastewater treatment plant will result in reduced cost of disposal of both. The cost of landfilling the yard wastes and the organic waste will be significantly reduced, and the increased Biogas produced can be used to generate even more electricity at the WWTP.
|Recommendation Identifier||Recommendation||Implementation Timeframe||Cost Expectation|
|A. Increase Drop Site Utilization and Efficiency||1. The City of Asheboro should dedicate staff resources for the development of a public awareness and education campaign that will inform the public as to the convenience and benefit of utilizing the drop sites for recycling. Greater opportunity exists for businesses that are not currently being served by recycling pick-up, as well as people that reside outside the City but frequently travel to the City.||Immediate||<$20,000 in near-term investment. Expected payback in less than 3 years.|
|B. Divert Comingled Curb-side Recyclables||1. The City of Asheboro should dedicate staff resources for the development of a public awareness and education campaign that will inform the public as to the convenience and benefit of utilizing the curb-side pickup containers for recycling.
2. The education program should focus on the benefit to the City, and ultimately the tax payers, in improving this program.
3. The City should adopt and enforce strict penalties for customers that violate the recycling container policy by placing unacceptable materials in the curb-side recycling containers.
|Immediate||<$30,000 in near-term investment. Expected payback in less than 1 year.|
|C. Anaerobic Digestion of Organic Wastes||1. Mechanical Biological Treatment of the organic portion of the MSW may create significant cost savings through diversion of a portion of the organic waste through the existing anaerobic digestion at the City’s WWTP. The additional biogas produced will create opportunity for the City of Asheboro to generate electricity, offsetting the cost of operations of the wastewater plant.||3-5 Years||Depending on the required capital improvements, $250,000 – $3,000,000|
|D. Development of Composting Facility||1. Anaerobic sludge stemming from the City’s wastewater treatment plant currently represents another form of solid waste disposal cost for the City.
2. The City has a growing problem associated with the lack of disposal of collected yard waste that is currently being stockpiled.
3. These two waste streams may be combined at a centralized composting facility, resulting in the potential for reduced sludge disposal costs, as well as providing a mechanism for addressing the yard waste disposal problem that is mounting.
|3-5 Years||Depending on the required capital improvements, $2,000,000 – $5,000,000|
- The City has reduced costs by removing the “middle man” in the process of selling recyclables, through internalizing solid waste collection fleet ownership and maintenance.
- Significant opportunities were identifoed by Cavanaugh to reduce the tonnage of materials landfilled, and the associated disposal and transportation costs, through improvements in the effectiveness of the drop site recycling program.
- Comingled recyclables collected curb-side are currently being sent to, and processed by, Asheboro Recycling. At the time of this study, Asheboro Recycling was baling these materials and charging the City $30 per ton to manage these materials. Significant opportunities were identified by Cavanaugh to reduce transportation and disposal costs, as well as increase recycling revenues, through the City’s direct management of these recycled materials.
- Cavanaugh identified and valued opportunities for the City to divert organic wastes from the municipal solid waste that is collected, further reducing transportation and disposal costs, and creating new sources of revenue.
- Several organic industrial wastes were identified by Cavanaugh within the City’s service area that were being managed through facilities other than those owned and operated by the City of Asheboro. Cavanaugh revealed the value of harvesting these materials to the City and the waste generators, resulting in a re-direction of these materials to the City. Feeding these materials into the existing anaerobic digesters at the City’s WWTP resulted in additional waste management revenues for the City, reduced costs for the generator, and additional biogas for energy generation at the City’s WWTP. The additional carbon infeed also provided for improved performance of the WWTP, resulting in reduced operating costs for wastewater treatment.