California has approved the world’s first requirements for testing drinking water sources for microplastics.
According to the San Francisco Chronicle and CalMatters, regulators with the State Water Resources Control Board approved a policy handbook that provides plans for quarterly, standardized testing through up to 30 of the state’s water providers. The testing would begin in the fall of 2023.
According to the handbook, extensive study between several laboratories developed two standardized methodologies for analyzing microplastics in drinking water: one uses infrared spectroscopy, and the other Raman spectroscopy. There are also efforts to develop other analytical methods, which the State Water Board may approve in the future.
The first phase of the testing plan (Fall 2023 through Fall 2025) will only deal with drinking water sources for the first two years, and will only test for microplastics larger than 20 or 50 micrometers in length.
Testing might become more frequent after this first phase: while there are currently very few laboratories capable of testing for microplastics in drinking water, the State Water Board expects more laboratories to be available after two years. The Board is also beginning an Environmental Laboratory Accreditation Program to help qualified laboratories become accredited to monitor for microplastics.
The second phase (Fall 2026 through Fall 2028) will begin testing treated drinking water for microplastics that are both smaller and larger than 20 micrometers in length.
The vast majority of monitoring orders during the first phase will affect large community water systems that serve more than 100,000 people, but all public water systems serving over 3,300 will be required to monitor for microplastics. The handbook also says that a “representative sample” of public water systems serving fewer than 3,300 people will need to monitor for the contaminant.
The State Water Board will hold public workshops with water systems to plan procedures such as sampling locations and quality control.
The program was first mandated through a 2018 state law, which required monitoring water for microplastics. It mandated four years of testing but didn’t set enforceable treatment limits for the quantities of microplastics found.
While the program gets underway, the State Water Board has plans to continue looking into research on different monitoring methods and on the effects of microplastics on human health.
