- 1:40 - 2:10PM | Microplastics = Macro-Problem!
Speaker: Sarah Wilkerson, CESSWI, Senior Stormwater Specialist - City of Springfield
Education Track: Stormwater Management | MS4 Management
Like many Cities across the country, the City of Springfield generates waste, and improper handling of this material through littering, open trash containers, and exposure to wind and water, results in a portion of this waste making its way into local waterways. Recent trash assessments of local streams found an average of 139 pieces of individual trash per 100 linear feet of stream. Trash was divided into categories (plastic, metal, glass, paper, etc.) and ranged in size from small cigarette butts to large items like furniture and tires. Plastic made up 60% of all trash surveyed, and of this plastic material, the majority was single-use food related plastics, followed in second place by plastic bags. Even more concerning, plastic continues to breakdown into smaller and smaller pieces, called microplastics. These tiny, man-made particles persist in the environment indefinitely, moving through all phases of the water cycle and passing up the food chain through a process called bioaccumulation.
Seeing the issue at hand, the City paid for an Environmental Intern to conduct research on the prevalence of trash and plastic in urban stormwater. While there is a great deal of research on microplastics in marine ecosystems, the intersection of microplastics and stormwater is currently an emerging area of focus. The intern, a pre-med student at Drury University, conducted stormwater sampling, laboratory studies, and stream trash assessments to provide a better picture of the composition and quantity of plastic in the urban environment. Stormwater samples were collected at several locations, including a parking lot, an industrial facility, and a turf field. In addition, samples were taken upstream and downstream of constructed SCMs, a detention basin and a bioretention basin. These samples were analyzed using laboratory equipment and AI software to calculate total particles in stormwater samples.
An important part of this research project was evaluating the efficacy of SCMs at microplastic removal. To evaluate the ability of stormwater detention basins at removing plastic, sediment samples were taken at the detention basin sampling site and evaluated for the presence of microplastics. To further study the effectiveness of bioretention systems at plastic-removal, a laboratory study was conducted which utilized buckets containing bioretention soil mix and a combination of turf grass and native plants. Additional data regarding the volume of trash in urban waterways was gained through numerous field assessments. From these studies, a clearer picture began to emerge of the scope of trash pollution and the presence of microplastics in stormwater runoff.
At this presentation, we will share photos of actual microplastic fibers and granules captured under the microscope, as well as the results of the stormwater sampling study and bioretention laboratory study. Join us as we take a tour of the tiny and slightly terrifying world of microplastics!
Learning Objectives
Understand the reasons why microplastics are a concern in urban stormwater runoff and be knowledgeable about the scope of the issue.
Understand different sampling and testing methods for quantifying microplastics in urban stormwater runoff, sediment samples and surface waters.
Understand the ability of various green infrastructure stormwater control measures (SCMs) to remove microplastics from stormwater runoff.
- 2:10 - 2:30PM | Break with Exhibitors