Microplastics collection method transferred to end users during pair of workshops

SCCWRP and its partners have begun the process of transferring to end users a newly standardized method for collecting samples from drinking water treatment plants in preparation for measuring their microplastics content.

During a pair of workshops in February at SCCWRP and the San Francisco Bay Area, respectively, that attracted a combined 120 attendees, attendees were introduced to a sample collection method developed by the University of Toronto that researchers found is most efficient at capturing microplastic particles while mitigating potential airborne contamination.

The work is part of California’s ongoing effort to develop a comprehensive statewide monitoring program capable of generating high-quality, directly comparable data on the prevalence and spread of microplastics across diverse aquatic settings. Under a policy approved by the State Water Resources Control Board in 2022, drinking water agencies are being required to monitor microplastics for an initial four-year period.

The University of Toronto method was standardized following a two-year study that compared the performance of an open-system method approved by the American Society for Testing and Materials (ASTM) and a University of Toronto closed-system method. Drinking water samples can require filtering thousands of liters of water to collect enough microplastics particles to become measurable, underscoring the challenge posed by airborne contamination.