California begins testing drinking water for Micro Plastics

The ubiquitous use of plastic in our modern world and inadequate management of plastic waste has led to increased contamination of freshwater, estuary and marine environments. The U.N. Food and Agriculture Organization (FAO) estimated that in between 4.8 million to 12.7 million metric tons (tonnes) of plastic waste each year.  Research on pollution from small plastic particles less than 5 millimeters in size, called micro plastics, has long focused on ocean pollution where most of the plastic residue ends up.

However, in the last decade, scientists have begun to study the microplastics in freshwater and land. It was first reported that microplastics were found in freshwater lakes in 2013. Though oceans represent the largest sink of persistent plastic waste, an estimated 80% of the microplastics pollution in the oceans comes from the land. The plastics flow to the oceans and lakes from our rivers. Microplastics contamination as seen in marine animals has also been found in freshwater organisms.

Microplastics end up in the soil environment from sewage sludge that is widely applied to agricultural lands. Fibers from laundry end up in the sewage sludge and it is spread on the land. Other sources of microplastics are weathering and disintegration of plastic sheeting used in agriculture, the fragmentation of plastic litter and plastic items both litter and in landfills. 

In September 2018, Senate Bill No. 1422 was filed with the Secretary of State in California , adding section 116376 to the Health and Safety Code, and requiring the State Water Board to adopt a definition of microplastics in drinking water,and adopt a standard methodology to be used in the testing of drinking waterfor microplastics and requirements for four years of testing and reporting ofmicroplastics in drinking water, including public disclosure of those results.

A year later than originally planned, the California Water Resource Control Board (Water Board) last week approved the world’s first requirements for testing microplastics in drinking water sources. This is the first step towards regulating the micro plastics that are ubiquitous in the environment. 

California Water Board unanimously approved a policy handbook for testing water supplies for microplastics over four years as required under the law. Under the plan up to 30 of the state’s largest water providers will be ordered to start quarterly testing for two years, beginning in the fall of 2023 to determine how widespread microplastics are in drinking water. It is anticipated that this data will be used to develop guidelines establishing the levels that are safe to drink.