Composting is a viable and important technology for managing organic wastes, as are modern landfills with comprehensive landfill gas collection and utilization systems. Both of these approaches have different capabilities and limitations. Understanding the facets of each approach allows individual communities to make waste management decisions, based on facts by environmental engineers that are beneficial for both human health and the environment.
SCS recently authored a report for the Metro Waste Authority in Des Moines, Iowa regarding their yard waste compost operations. Metro Waste’s yard waste compost system includes a bag and sticker program to support separate yard waste collection, shredding, screening, and windrow composting at the Metro Compost Center, which is co-located atop a closed City of Des Moines Landfill, and at the active Metro Park East Landfill.
The SCS report evaluated the costs, greenhouse gas emissions, carbon sequestration, and the advantages and the disadvantages of continuing their current operations or alternatively considering a partial or full closing of the compost operations. If operations are reduced or stopped, these materials would be disposed of in the active municipal solid waste landfill. The active landfill has a comprehensive gas collection system, and Waste Management owns and operates an 11.2 Megawatt landfill gas-to-energy facility at the landfill.
The report was used by the Metro Waste Authority in early 2015 to support an amendment to Iowa’s solid waste regulations. The amendment allows for yard waste to be disposed of and be managed in landfills, only if the landfill has an active landfill gas collection and control system with a landfill gas-to-energy facility to effectively control and reduce methane emissions. The legislation was passed as a restricted exemption to the State’s ban on yard waste disposal in landfills. The amendment in the State’s regulations provides landfill operators some flexibility in managing these types of materials, as other states have done as well.
Most media channels fully informed their readers of the science and function of both technologies, explaining that when considering all factors, one landfill operation can reap greater environmental benefits than another operation despite using the same solution. Some organizations view the law and the report prepared by SCS as “anti” composting, or that because SCS’s investigative analysis and report proposed options, SCS does not support composting. SCS Engineers fully supports composting. In fact, we design, permit, and operate compost facilities around the nation.