Microplastics added as focal point in SMC street sweeping study

Researchers will investigate the effectiveness of street sweeping in removing microplastics that enter storm drains and contribute to runoff pollution as part of a newly launched Southern California Stormwater Monitoring Coalition (SMC) study quantifying street sweeping’s effectiveness in removing multiple common types of stormwater contaminants.

The SCCWRP-led study, which held its first advisory committee meeting in April, is measuring how much bacteria, nutrients, trace metals and other common stormwater contaminants are transported from streets into storm drains during wet-weather flows, and if street sweeping is effective in preventing the transport of at least some of this pollution into storm drains.

The City of Santa Barbara recently decided to join the study and leverage the study design to also investigate microplastics, thereby enabling researchers to extend the study’s focus beyond traditional runoff pollutants.

The study represents the first known field-scale effort to isolate and study just the portion of street pollution that gets removed during routine street sweeping. One set of street segments will be swept, while a corresponding set of similar street segments that will serve as the control group will not be swept. A rainfall simulator custom-made by SCCWRP will be used to create controlled rainfall patterns for both street segments.