3/10/22
Vermont Legislature Considers Bill on Microplastics

In this year’s legislative session, Vermont State Representative James McCollough, of Williston, introduced H-501, “an act related to physical contaminant standards for residual waste, digestate, and soil amendments”, specifically “physical contaminants” also known as microplastics.  As originally introduced, H-501 raised many concerns for the Green Mountain Water Environment Association (GMWEA)’s Government Affairs Committee that tracks regulations of interest.  H-501 was originally directing the Secretary of the Natural Resources to limit physical contaminants in solids wastes, composts, biosolids, digestate, and domestic septage, among other types of wastes, to not more than 0.5% dry weight of particles larger than 1 millimeter (mm), and no more than 20% of that 0.5% dry weight shall be film plastic greater than 1 mm in size. 

Numerous interested parties testified during the bill’s hearing, including the Composting Association of Vermont.  The testimony was very focused on the food waste “depackaging” facility operated by Casella Organics in Williston that opened with great fanfare back in 2021 (see Casella Waste Systems unpacks batches of spoiled food to be recycled (burlingtonfreepress.com)).  Microplastics was a topic of conversation when that facility was being proposed and the topic came back around in discussions about H-501. 

Microplastics are yet another contaminant of emerging concern for biosolids/residuals producers and managers.  Major concern about microplastics, to date, has focused on particles ending up in the ocean and in surface waters. With large surface area, the concern is that microplastics can absorb toxics and be passed on up the food chain.  Ingestion and inhalation seem to be the two biggest exposure pathways for humans but there is scant solid research on health impacts.  And these tiny particles are being found everywhere, including in water, food, and even baby poop. It is in soils and composts – especially composts made from food wastes.   NEBRA members can access past research abstracts compilations on microplastics (https://www.nebiosolids.org/nebra-members) that date as far back as May 2015.  The most recent compilation, with comments from Professor Sally Brown of the University of Washington, is from February 2022. 

Measuring and quantifying these tiny plastic particles is an evolving science and there are no standard methods for doing so.  Researchers at the University of Vermont started looking at microplastics back in 2019 (see Microplastics Measurement, Related Legislation In Vermont | BioCycle).  That same research team recently published a policy paper related to Microplastics in Composts, Digestates and Food Wastes: A Review | Engineering Archive (engrxiv.org).  The lead author, Katherine Porterfield, won the NEBRA student poster contest back in 2020 as a graduate student, presenting the UVM project on “Phosphorus Recovery and Reuse from Anaerobically Digested (AD) Dairy Manure”.   UVM’s interest in AD efficiency has also led to looking at microplastics.  Under a grant from the U.S. Environmental Protection Agency, UVM researchers will attempt to quantify the impacts of food waste use in AD on nutrient cycling and microplastics fate.   

The State of Vermont has begun a deeper dive into microplastics.  Although the amended version of H-501 does not appear to impact the residuals recycling programs directly, the Vermont Department of Agriculture is very concerned about microplastics.  The Department of Environmental Conservation has also begun to assess the situation.  Source reduction will be critical and, as always, the most cost-effective way to head off this emerging contaminant. 

The analogy of microplastics to PFAS can’t be helped.  Like PFAS, microplastics are everywhere.  Microplastics don’t readily degrade. The tiny contaminants are difficult to analyze and quantify.  Current wastewater treatment processes are not designed to remove microplastics and there are still a lot of unknowns regarding their fate and transport in the environment and their health effects. 

As approved on February 25th by the House Committee on Natural Resources, Fish, and Wildlife, H-501, now “An act relating to the regulation of food depackaging facilities”, goes to the full House and, if approved, will cross over to the Senate by the end of this week.  See Documents & Handouts | House Committee on Natural Resources, Fish, and Wildlife (vermont.gov).  Microplastics – and their presence in biosolids, composts and other soil amendments -- is sure to be a future topic for the Vermont legislature.