Waste Composition Studies

A waste composition study is a detailed analysis of materials found in a particular waste stream. The data gathered in this process can provide valuable insights about program performance and opportunities for improvement.

CIF/SO funded waste composition studies

Since 2012, the CIF has provided funding for waste composition studies and program auditing. In December 2015, WDO negotiated an agreement under which SO and CIF would jointly fund a series of municipal waste composition studies over a period of three years. The Terms of Reference standardizes the study methodology, funding and project coordination, benefiting all stakeholders.

Determining sample size

Sample size refers to the number of households that are examined in any given waste composition study. How many households need to be studied to be confident that the results are representative of the entire community?

Three key questions should be considered when deciding the sample size:

How homogeneous is the group you want to know about?

If you want the results to be representative of an entire municipality, consider how households may differ in certain areas. This could include urban, rural and seasonal segments, high-income and low-income neighbourhoods, and other demographics.

Do levels of waste-service differ?

Consider whether certain areas receive a different level of service than others.

What question are you trying to answer?

Think carefully about how you will use the results of the waste composition study. Are you only interested in big-picture trends or do you want to know about a specific material? If you want to know about a rare or very specific material (e.g., sneakers, or white HDPE containers), you’ll need a larger sample size than if you only want information on how much households recycle.

Time, budget and resource constraints will always limit the number of households that can be included in a study. The challenge is to decide how best to examine the issues in question and address identified variables in the population.

Try the Tool

The CIF has developed a Waste Composition Sample Size Calculator to help municipalities determine the appropriate number of households and areas needed to achieve statistical significance. To get started, download the Instructional Guide, which contains links to the software and files needed to run the calculator.

The calculator runs in a program called RStudio, which is free to download and install, but can be complicated for new users. For assistance, please reach out to CIF Staff.

Composition studies at depots

To complete a waste composition study for programs that only use depots, pre-screening users is required.

considerations for small communities

In 2012, the CIF developed “Curbside Waste Audits: Considerations for Small Communities”, as a step-by-step guide to the planning, collection, sorting and analysis involved in a waste composition study.

MRF audit guide

The CIF has developed “MRF Audit Guide: Material Stream Compositions” to provide municipalities with a reference document for planning composition studies of Blue Box recyclables received at the MRF. The guide can be used as a reference or inserted as an appendix into RFP/Tender documents for any municipality that’s establishing a new processing contract. Terms in the contract will permit a municipality to enter/audit the inbound, sorted or residue materials at the MRF and the guide will help set out the general procedures for conducting the audits.

For more information on this topic, contact CIF Staff or the CIF project contact, Jean-Louis Gaudet, of EXP.