Conducting a Waste Characterization Study: Overview
Waste characterization is a method used to determine the types of materials being discarded in a waste stream and in what proportion. Waste characterization information can help policy makers and city planners reduce landfill waste, set up recycling programs, and conserve money and resources. In fact, a waste characterization study typically preceds waste diversion studies and strategies.
To conduct a characterization study, data must be collected by taking representative samples of waste and sorting it into material types like newspaper and aluminum cans, and weighing each type. Samples can be taken from trucks delivering waste to landfills and transfer stations from residential, commercial, and self-haul sources.
The following are the major steps to complete a waste characterization study:
- Select Approach: Landfill sampling, waste generator sampling, use of existing data, combination of approaches
- Collect Representative Data: select samples for field studies, determine number of samples needed
- Use Protocols: uniform field sorting protocols, material type definitions, lumping material categories, classifying composites
- Health and Safety: determine safety protocol before conducting field studies
- Data Analysis: random sampling (landfill) vs. subdivision of sectors (generator)
RATIONALE
Characterization studies allow cities to map their entire waste stream and to identify gaps so that they can focus their efforts on diverting the most appropriate materials that will have the greatest impact. Depending on local conditions, material types selected for study can be besed on volume generated, difficulty of collection and processing, or recyclability and reuse potential. Each city will have to determine for themselves which material types and selection criteria make the most sense, but having this information will make the process easier and improve diversion efforts.
EFFORT REQUIRED
The effort required to perform a waste characterization study will depend on the size of the community because that will determine the required sample size. The length of the study and the number of samples taken over that period will also be important considerations. It is a good idea to collect samples over multiple seasons to account for changes in climate, demography, and commerce. ASTM Standards require a minimum sample weight of 200 lbs for unprocessed MSW, and the CIWMB suggests at least 30 samples for residential waste and 40 for commercial generators.
BENEFITS
- Get a "big picture" understanding of waste stream
- Saves money and resources
RISKS
- Use of non-representative samples that skew results
ACTION AGENT(S)
- Environmental Management Department
- Solid Waste Management/Recycling Department
- Public Works Department
COST
Study costs will vary depending on sample sizes, counting methods, the number of samples taken, and length of the study.
Waste disposal sites for solid waste from human activities.The disposal of waste other than through incineration or the use of landfills. Examples include reuse and recycling.The collection, reprocessing, marketing, and use of materials that were diverted or recovered from the solid waste stream.The overall flow of waste from consumers to a landfill, incinerator, or other disposal site.
