Robeson County Landfill
The Robeson County Landfill began operating a landfill gas collection and flaring project in July 2008. The project benefits climate change strategies by reducing the amount of greenhouse gases (methane) that would otherwise be released from the landfill.
Robeson County is negotiating with potential end-users who will use the landfill gas for industrial process heat or for electricity generation. As discussions with potential end-users continue, the methane is destroyed in an open flare. Currently, carbon revenue is the only funding source which is proceeding as anticipated, and TerraPass funds are the only financial return available for this project at the current time.
This project has been verified under the Climate Action Reserve offset protocol.
Project details
The Robeson County Landfill is a medium sized municipal solid waste facility located about 5 miles east of downtown St. Pauls, NC. The gas collection system is designed in two parts: one part extracts gas from “Phase 1” of the landfill, while the second part extracts gas from the active cells.
“Phase 1” of the landfill opened in 1985 and was closed to municipal solid waste in 1997. Construction and demolition waste is still accepted in this area. Seventeen gas wells service this part of the landfill.
The active sections of the landfill (Phases 2 and 3) have accepted waste since 1997. The gas collection system in these areas includes horizontal gas collection pipes as these cells are filled, as well as vertical wells. Approximately 46 wells will be installed over time in Phases 2 and 3. The system design employs an advanced looped configuration that allows individual sections of the collection system to be operated independently. This increases gas collection efficiency across the active cells, as gas can then be collected and destroyed from some sections without affecting waste disposal.
The gas vacuum blower and open utility flare are sized to handle the maximum gas flow rate from both areas. Landfill gas flow is measured by a continuous flow meter just upstream of the flare. The system and flare came online in July 2008.
Project location
The project is located in St. Pauls, North Carolina.
Other social and environmental benefits and costs
Environmental benefits
- Prevention of odor in surrounding areas.
- Improvement in air quality such as reductions in volatile organic carbon emissions.
Social benefits
- Construction and maintenance jobs related to the project.
Project’s ability to foster further greenhouse gas emission reductions
- The design in the active waste cells is configured to allow select portions of the gas collection system to be turned on while receiving waste. This increases the amount of landfill gas collected from active waste disposal areas, which would otherwise be vented to the atmosphere while the cells remain open.
Project’s environmental and social costs
- There are no major environmental or social costs associated with this project.
Discussion of appropriate use of TerraPass funds
TerraPass considers many aspects of projects before deciding whether to fund them. Here is a summary of key considerations for this project:
Baseline conditions
Phase 1 of the landfill was constructed before federal regulations governing landfill liners had been promulgated. As a result, this older landfill section is unlined and small quantities of contaminants have been found in some onsite groundwater monitoring wells. The County has addressed this issue with several actions over the past 5-8 years. One such action has been to construct and then extend a trench which allows landfill gas to vent more easily to the atmosphere. Several years after construction of this trench, passive candlestick-type flares were added as a preventive measure to ensure the vented landfill gas did not build up at the surface of the trench. No gas collection system existed at the landfill prior to July 2008.
The U.S. EPA reports that of the 2,300 or so currently operating or recently closed US landfills, only about 400 have gas use projects, indicating that these projects are not standard practice in the industry.
Additionality
No regulatory requirements.
The landfill’s design capacity is below EPA’s New Source Performance Standard (NSPS) threshold for air permitting, meaning no air permit or gas collection and destruction system is required. Similarly, no state or local regulations require the landfill to combust its landfill gas. As noted above, the landfill chose to add small passive flares to its venting trench a few years ago, but this decision was not necessitated by any regulatory requirement.
Impact of TerraPass funds.
Robeson County had originally secured an end-use arrangement with a company that planned to locate a new plant near the landfill. However, the plant’s construction has been delayed and grant funding to help underwrite construction of the landfill gas system has been withheld as it was tied to the new industrial plant. As a result, carbon revenue is the only funding source which is proceeding as anticipated, and TerraPass funds are the only financial return available for this project at the current time.
Better than most.
Robeson began exploring possible uses for its landfill gas in 2006, and at that time analyzed many sources of revenue to support the project, including carbon credits. The County has aggressively sought ways to turn its landfill into an asset for the community, while improving its environmental profile.
