Keeping Organics Out of the Landfill
Disposing of organic materials such as food waste in landfills results in production of methane, a highly potent greenhouse gas. In BC, waste management accounts for about 5% of the total greenhouse gas emissions . It is also challenging to capture and utilize all of the methane that is generated in many landfills.
Managing organic materials that are traditionally part of the waste stream using other, low-emission methods is becoming a key part of waste management, or ideally resource management strategies for local governments. Not only does diverting organics from the landfill reduce methane emissions, it allows this valuable resource to be reclaimed for other beneficial uses.
Local Governments and Organics Management
In BC, many local governments, particularly regional districts, manage landfills. Many existing landfills are generating emissions from previously disposed waste; the proposed BC Landfill Gas Regulation aims to maximize reductions of landfill gas emissions and identify opportunities to increase landfill gas recovery and its beneficial use.
The Carbon Neutral framework for local governments currently does not recognize emissions reductions for landfills. However, these emissions are real and local governments can play a significant role in preventing useful organic resources from becoming potent emissions sources that cannot practically be recovered.
To facilitate organics diversion and resource recovery, local governments actions can include:
Set diversion and disposal targets for organic wastes – these may be part of resource management plans, zero waste strategies or other policies
Explore the opportunities for setting up community-scale/centralized organics collection and composting or other processing services
Work with private waste management services to provide collection and/or composting or processing services
Work with adjacent/regional governments to develop shared solutions
Promote and possibly subsidize backyard and apartment composting bins
Ban organic waste from the landfill, in conjunction with setting up alternate management services
Co-locate composting or other organics processing facilities with complementary facilities, such as wastewater treatment plants that produce biosolids
Low-Emissions Management Solutions
US EPA information indicates that there is a substantial reduction in net greenhouse gas emissions due to diverting readily degradable organic materials such as food trimmings to other methods such as composting, compared to landfilling.
I would argue that trying to build a more sustainable, carbon-neutral society without an aggressive approach to organics, would be like trying to get from one place to another by walking on a treadmill. Margo Reid Brown, Chair of the California Integrated Waste Management Board, Biocycle journal
Composting of organic materials is one of the solutions chosen by many governments and organizations to manage organic resources. There are a wide variety of methods and technologies available, many of which are relatively simple and require minimal energy input, others that are more intensive and mechanized, depending on site constraints and other factors. Compostable materials include:
Yard and garden trimmings
Agricultural residues and manures
Different materials can be co-composted, potentially increasing the economic viability of composting operations.
All composting processes produce a useful, stable product that can be used to enhance soil quality and fertility, maintaining carbon storage in the soil and enhancing the ability of plants to sequester carbon from the atmosphere.
Other Management Methods
Other organics management and processing methods include anaerobic digestion (AD), which is suited to readily degradable organics such as food waste. AD produces biogas that can be used as a fuel source (typically for heating and power generation). Like composting, AD facilities can potentially handle multiple materials, including food waste, biosolids and manure. However, AD systems tend to be cost effective only at larger scales, due to the capital cost of equipment.
Less degradable organic materials such as wood waste can be co-composted with other materials such as food or biosolids, or can be potentially be processed into fuels using other technology such as gasification.
Major considerations for organics collection and management include the potential for attracting wildlife and odour generation. These issues must be carefully considered in the design of programs and facilities.
The Regional District of Nanaimo has developed an Organics Diversion Strategy. Major initiatives include banning commercial organic waste from the regional landfill in 2005, and launching a residential food waste collection pilot program in 2007. Composting services are provided by International Composting Corporation.
The first municipality in B.C. to introduce universal residential curbside pick-up of organic waste, Ladysmith is dramatically reducing the amount of waste going into the landfill.
The District of Squamish, in partnership with Carney’s Waste Systems, provides organics composting services, and plans rollout of organics collection in 2009.