At today’s State Water Resources Control Board (SWRCB) meeting, the Board voted to adopt the proposed definition of microplastics in drinking water.
In 2018 California adopted a new law that required the SWRCB Division of Drinking Water (DDW) adopt a definition of microplastics in drinking water before July 1, 2020.
On March 24, 2020 the SWRCB DDW published for a 30-day public comment period a proposed definition of microplastics in drinking water. A copy of DDW’s responses to the public comments is enclosed (Microplastics_DDW Response to Public Comments_draft).
Prior to today’s Board meeting, based on public comments, DDW staff made the following changes in the proposed definition: DDW staff changed the phrase “which have at least two dimensions that are greater than 1 and less than 5,000 micrometers” to “which have at least three dimensions that are greater than 1 nm and less than 5,000 micrometers.”
The enclosed document DDW Staff Report Microplastics_Revised (DDW Staff Report Microplastics_Revised) includes the proposed definition of microplastics as presented today to the SWRCB members. During today’s meeting a minor change was made to footnote #3 (size-based nomenclature) of the proposed definition.
The 2018 law requires that by July 1, 2021 the SWRCB must adopt test methodology for microplastics in drinking water, adopt requirements for four years of testing and reporting on microplastics in drinking water, and develop accreditation requirements for laboratories to analyze microplastics.