Operation Sweep the Creek

There are many sources of plastic pollution, some of which are not your typical bottle or straw. One less familiar source of plastic pollution is pre-production pellets. Pellets are used in the manufacturing stages of a plastic product’s lifecycle and are typically characterized by their distinctive spherical/cylindrical shape and 2-5mm size. During plastic production, pellets are melted down and injected or extruded into molds to form a desired product.


During some operations, such as shipping and transporting, their light weight and small size makes them vulnerable to loss. Thus, during operations, pellets can be emitted into the environment without extra precaution. When coupled with precipitation events, pellets are swept into freshwater bodies through runoff from storm and waste water channels. Without proper containment strategies, these pellets eventually accumulate in larger bodies of water and contribute to larger masses of plastic contamination.

HumberBayParkWestHumber park

As a result, studies have shown the presence of pre-production pellets on Canadian shorelines and in tributaries. Researchers have also demonstrated a positive correlation between the presence of plastics-related companies and the quantity of pellets found in the environment.

As a collaboration between our group at the University of Toronto, the Ontario Ministry of Environment, Conservation, and Parks (MECP), and the Canadian Plastics Industry Association (CPIA), we are taking a tiered-approach aimed at reducing pellet contamination from the source. Nicholas Tsui, an MSc student from UTM’s Sustainability Management program, is leading this project to quantify and characterize pellets in the field and collaborate with industry stakeholders to reduce emissions. We have focused the scope of this project in Mimico Creek, an urbanized watershed that includes parts of Brampton, Mississauga, and Toronto.


Through this project, we hope to demonstrate the following:

  1. A success story showing collaboration between different stakeholders such as academia, government, and industry to demonstrate sustainability stewardship.
  2. A reduction in pellets emissions in Mimico Creek after implementing outreach initiatives.

If you’re interested in learning more, contact Nicholas through email at Nicholas.tsui@mail.utoronto.ca.