State Water Board Addresses Microplastics In Drinking Water To Encourage Public Water System Awareness

First in Nation Effort Begins Multi-Year Process Toward the Study and Monitoring of Public Water Supplies

The State Water Board is leading an ambitious international effort to standardize methods for monitoring microplastics in drinking water, surface water, sediment and fish tissue. In a critical first step to further the understanding of microplastics in our drinking water and the environment, the Board today adopted an official definition of “microplastics” in drinking water.

The definition sets the foundation for a long-term approach to studying this ubiquitous contaminant, which recently has come into mainstream awareness as a major environmental challenge. Researchers believe further monitoring and study of microplastics in drinking water supplies and its implications for public health and safety are imperative.

“The science, research and understanding of microplastics is fast moving,” said E. Joaquin Esquivel, chair of the State Water Board. “This first, but critical step, in establishing a definition of microplastics in drinking water will provide the basis for further investigation and work at the Water Boards. Plastic pollution is a challenge throughout our watersheds, from large plastics such as bottles, bags, and other refuse, to microscopic pieces that this definition attempts to better define. We must find ways to comprehensively address the problem, and the Water Board looks forward to guiding the discussion on how best to do so."

Microplastics are plastic particles less than 5 millimeters in length - a size that has long concerned scientists due to its potential ingestion by animals. Many of these particles are much smaller and can only be seen through a microscope. While other state, national and international agencies have defined microplastics, California’s definition is the first to focus specifically on microplastics in drinking water.

Today’s State Water Board action is in response to Senate Bill 1422, legislation passed in 2018 that required Board adoption of a definition of microplastics in drinking water by July 1 of this year. Specifically, the bill mandates establishment by July 1, 2021, of a standard methodology that requires four years of testing and reporting the results, including public disclosure of the findings.

As a result of the legislation related to microplastics in drinking water, as well as Senate Bill 1263 that requires adoption of a Statewide Microplastics Strategy to protect coastal waters, the State Water Board is collaborating with the Ocean Protection Council and the Southern California Coastal Water Research Program to lead an ambitious, international effort to standardize methods for monitoring microplastics in drinking water, surface water, sediment and fish tissue. Experts will convene to better understand the human health and ecological effects. For more information, please visit the State Water Board’s Division of Drinking Water Program’s resources page.

The State Water Board’s mission is to preserve, enhance and restore the quality of California’s water resources and drinking water for the protection of the environment, public health and all beneficial uses, and to ensure proper water resource allocation and efficient use for current and future generations.