Abstract

Overconsumption is an important issue when considering the causes of environmental deterioration because of its close relation to waste production.  In Alberta, waste generation per capita increased 5% from 2004 to 2008 during an initiative to decrease waste generation by over 30%.  Because consumption is related to consumer preferences and is inherently behavioral, one might consider convincing people to consume less to be a difficult task.  The following project is based on a plan to reduce the waste burden in Alberta by recycling leaf and yard waste.  Leaf and yard waste was targeted because it makes up a large portion of municipal solid waste, approximately 10%.  It is also a relatively clean organic material that can be readily and locally recycled, its recycling technologies are well known, and local markets and end users are available.  The Leaf and Yard Waste Technical Committee, which was formed in 2006, recommended a feasibility study to determine the effectiveness of a program to divert leaf and yard waste from landfills, to be composted and subsequently reused for land application. A landfill is a site at which materials are stored where they can undergo anaerobic decomposition. Composting is the biological decomposition of organic materials, under controlled circumstances. The composting discussed is maintained under aerobic conditions. The overall strategy of the proposed initiative is to prevent leaf and yard waste from decomposing anaerobically in a landfill where it will release methane (CH4) gas, and instead allow it to decompose aerobically in a composting system, where it will release CO2, a much less harmful green house gas. The purpose of this research project is to determine the potential carbon off-set credit as a result of this diversion. Calculations for landfill and aerobic composting emissions were based on the Specified Gas Emitters Regulation. The baseline emissions from the landfill were estimated to be 735,000 t CO2-e/y and 1,470 kg CO2-e/t leaf and yard waste. The composting project emissions were based on the following four components: (1) Material treatment, (2) Facility operation, (3) Fuel extraction, and (4) Residue decomposition. Collectively, the emissions from the composting project were estimated to be 90,112 t CO2-e/y and 180.2 kg CO2-e/t leaf and yard waste. Subtracting the project emissions from the baseline yields net carbon off-set credits of 644, 887 t CO2-e/y and 1,290 kg CO2-e/t leaf and yard waste.