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The State Water Resources Control Board – State of California (“Board”) issued a document titled:

Policy Handbook Establishing a Standard Method of Testing and Reporting of Microplastics in Drinking Water (“Policy Handbook”)

The Policy Handbook was prepared by the Division of Drinking Water of the Board.

The Board approved the Policy Handbook for sampling drinking water supplies for microplastics for potentially 30 of California’s biggest water providers.

Microplastics are defined by USGS as miniscule plastic fragments (smaller than 0.04 inches) that fall off decomposing plastic bottles and bags.

Microplastics have been found nearly everywhere, including lakes, rivers, and other waterbodies.

The Policy Handbook references a definition of “microplastics in drinking water” adopted by the Board as follows:

. . . solid polymeric material to which chemical additives or other substances may have been added, which are particles which have at least three dimensions that are greater than 1 nanometer and less than 5,000 micrometers. Polymers that are derived in nature that have not been chemically modified (other than by hydrolysis) are excluded.

An iterative, two-step, four-year plan for monitoring and reporting microplastics is prescribed. It states that to date:

. . . no government in the world has required monitoring for microplastics in drinking water, and the data obtained through the efforts detailed in this Policy Handbook will provide valuable insights for determining exposure to consumers through drinking water.

The Policy Handbook is a response to a mandate by California legislation which required the Board:

• Adopt a standard methodology to be used in the testing of drinking water for microplastics;
• Adopt requirements for four (4) years of testing and reporting of microplastics in drinking water, including public disclosure of those results;
• Consider issuing a notification level or other guidance to aid consumer interpretation of testing results; and
• Accredit qualified California laboratories to analyze microplastics.

A copy of the Policy Handbook can be downloaded here.