USEPA Project XL

Excellence in Leadership

Project XL is coordinated by EPA's Office of Policy, Economics, and Innovation. Project XL, which stands for "eXcellence in Leadership," was a national pilot program that allowed state and local governments, businesses and federal facilities to develop with EPA innovative strategies to test better or more cost-effective ways of achieving environmental and public health protection.

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The Buncombe County Solid Waste Management Facility is located in the mountains of western North Carolina, approximately nine miles north of the City of Asheville. The 557‐ acre solid waste management facility opened in 1997 and comprises a Subtitle D landfill, construction and demolition (C&D) landfill, wood waste mulching facility, convenience center for residential drop‐off, a household hazardous waste (HHW) facility, and a white goods and tires holding facility.

The Subtitle D landfill is 95 acres and consists of 10 disposal cells that are being constructed sequentially over the estimated 30+ year life of the facility. Cells 1 and 2 were constructed with a prescriptive RCRA Subtitle D liner system consisting of a 24” soil barrier layer with a maximum permeability of 1x10‐7cm/sec, a 60‐mil high density polyethylene (HDPE) liner and a 24‐inch rock drainage layer. Cells 3‐6 were constructed with an alternative liner system that uses an 18‐inch soil barrier layer with a maximum permeability of 1x10‐ 5cm/sec, a geosynthetic clay liner (GCL), a 60‐mil HDPE liner and a 24” rock drainage layer.

Cells 1‐5 are filled to capacity and Cell 6 has been the active disposal cell since 2006. Based on current waste flows Cell 7 is expected to begin operation in 2015.

The County believes that the leachate recirculation/gas recovery landfill approach would enable superior performance.

The goal of a bioreactor operation is to achieve a stabilized condition while the landfill is still being monitored and active, providing superior environmental performance in a number of ways:

  1. Acceleration of waste decomposition which should enhance groundwater protection
  2. Early compliance with Clean Air Act requirements for municipal solid waste landfills through installation of a gas collection and control systems
  3. Reduction in emissions as a result of producing a more efficient landfill gas
  4. Reduction of potential risk to workers and the community from transport of collected leachate to the POTW via tanker trucks
  5. Improved leachate quality and, ultimately, discharge water quality to the receiving stream
  6. Reinvestment of cost savings in pilot projects to enhance integrated solid waste management practices in Buncombe County
  7. Additional waste capacity and longer life of existing landfill cells, reducing the need for new landfill sites
  8. Evaluation of the horizontal trench design for leachate recirculation/gas recovery landfills by providing valuable large-scale operational data
  9. Identification and quantification of performance advantages or limitations of the process

Superior Environmental Performance will be measured by attempting to quantify the benefits against the baseline for this project.

EPA's RCRA Subtitle D regulations (40 CFR Part 258) currently allow for leachate derived from an municipal solid waste landfill (MSWLF) unit to be placed back into the landfill if the MSWLF unit is designed with the standard composite liner (i.e., 2 feet of 10-7 cm/sec permeability soil and a 60-mil HDPE synthetic liner) and leachate collection system specified in the regulations. Though the Subtitle D regulations provide a mechanism whereby alternative liner systems may be accepted by approved State programs (provided that they can be demonstrated at least as protective as the standard composite liner), an EPA policy memorandum documents that it is EPA's interpretation of the regulations that leachate can only be recirculated over landfill units constructed with the standard composite liner design.

Buncombe County’s Bioreactor was granted regulatory flexibility under project XL to add liquids to cells with alternative liner systems.

The USEPA intends for the modification of regulatory requirements allowed through project XL to meet the needs of the local communities while protecting the environment. For this reason, all XL projects require the participation of stakeholders.

Stakeholder involvement has played an essential role in the development of the Buncombe Bioreactor from its inceptions and will be critical to the success of the project. The stakeholders selected for participation in the project are:

  • Buncombe County Solid Waste
  • Buncombe County Board of Commissioners
  • U.S. Environmental Protection Agency
  • The North Carolina Chapter of the Solid Waste Association of North America
  • Western North Carolina Regional Air Quality Agency
  • North Carolina Department of Environment and Natural Resources Waste Management Division
  • Blue Ridge Environmental Defense League
  • Local Residents

In exchange, EPA issued regulatory, program, policy, or procedural flexibilities to conduct the experiment. Under Project XL private businesses, federal facilities, business sectors and state and local governments are conducting experiments that address the eight Project XL selection criteria:

  1. produce benefits such as cost savings, paperwork reduction, regulatory flexibility or other types of flexibility that serve as an incentive to both project sponsors and regulators
  2. supported by stakeholders
  3. achieve innovation/pollution prevention
  4. produce lessons or data that are transferable to other facilities
  5. demonstrate feasibility
  6. establish accountability through agreed upon methods of monitoring, reporting, and evaluations
  7. avoid shifting the risk burden, i.e., do not create worker safety or environmental justice problems as a result of the experiment

Additionally, if the applicant was a Project XL for Communities it was required to develop strategies that.

  1. present economic opportunity
  2. incorporate community planning

Landfill Gas -to- Energy Project

  • Gas to Energy - Phase 1
  • Gas to Energy - Phase 2
  • Gas to Energy - Phase 3
  • Gas to Energy - Phase 4
  • Gas to Energy - Phase 5
  • How it works!

    The landfill Gas to Energy Project began in 2012 with the installation of gas collection wells in the landfill. These wells trap the methane gas that is produced as trash decomposes in the landfill. Instead of releasing the powerful greenhouse gas into the air, which can negatively affect air quality, the wells capture it and divert it to run a generator. The generator creates electricity from this gas reducing demand on coal or natural gas which are both non-renewable resources.

    The generator will produce 1.4 megawatts of electricity, enough to power about 1,100 homes per year.

    This project has been funded in large part by a $4 million federal stimulus grant and loan which were awarded to Buncombe County. The electricity generated will be sold through a joint venture between Duke Energy and the French Broad co-op. Renewable energy credits will be sold to GreenCo Solutions to help cover the cost of the loan and operate the project. Renewable Energy Credits produce about $200,000 in revenue and the electricity sales produce around $600,000 to the County each year.

Latest Videos

  • 29 nov 2012

    Day in the Life - Landfill

    Follow along with Landfill employees to learn all about these revolutionary processes, in a Day in the Life of the Solid Waste Department.

  • 30 may 2012

    We are Buncombe County.

    We Are Buncombe County is a video showing the involvement of Buncombe County Government and all the great things Buncombe County has to offer.

  • 27 apr 2012

    Gas to Energy Ribbon Cutting

    Ribbon cutting ceremony for the Landfill Gas-to-Energy Generator project that took place on Friday, April 27th at the Buncombe County Landfill.