A postcard from the Annual W3170 Research Meeting

The W3170 group of land grant university researchers focus on soils and soil amendments and biosolids. In October, they will become the 4170 group, as their 5-year project renewal by the U. S. Department of Agriculture (USDA) was recently approved. This research group’s history is long and important, playing a key role in the 1980s and ‘90s on collaborative multi-state science that was part of the basis for the federal Part 503 biosolids rule. Meeting annually, W170 then W1170 then W1270 and W1370, these scientists have addressed metals, pathogens, emerging contaminants, odors, best management practices, and the benefits to soils and cropping systems of biosolids and residuals additions – including carbon sequestration and climate change mitigation.

This June 25 & 26, 2019, W3170 met at USDA headquarters in Beltsville, MD. Once again, as every year, they exchanged current research updates, revealed preliminary and final data, and challenged each other in scientific debate. Some have been around since W170: Nick Basta (The Ohio State University) and Lee Daniels and Chip Elliott (Penn State). Some from other early versions of the group: Jim Ippolito (Colorado State), Sally Brown (Univ. of WA), Ian Pepper (Univ. of AZ), and this year’s host, Greg Evanlyo (Virginia Tech). Some have joined in over time, including Ganga Hettiarachchi (Kansas State), Elisa D’Angelo (Univ. of KY), Carl Rosen (Univ. of MN), and Hui Lee (Michigan State), Brian Badgley (Virginia Tech), Linda Lee (Purdue), and Maria Silveira (Univ. of FL). And some were notably absent: George O’Connor (Univ. of Florida) has formally retired and moved away, but his rigorous challenging questioning was still noted and appreciated – and emulated as best as possible. This year, the meeting included regular municipal and government researchers including Chicago’s Guanglong Tian and U. S. EPA’s Carolyn Acheson and regional biosolids group and committee representatives Gregg Kester (CASA), Bill Toffey (MABA), Robert Crockett (VBC), Lynne Moss (WEAT), and I, Ned Beecher (NEBRA). What an honor to be in the presence rigorous scientists, absorbing what I could and marveling at what was going over my head.

There was talk of PFAS, yes, with the latest details from Linda Lee, including thes updates:

  • Data from total fluorine assays (PIGE) are suspect. Her lab analyzed dental floss alleged to contain PFAS and found none. It may contain F, but so does toothpaste, and F is not the same as PFAS.

  • Contamination of lab samples remains a problem. PFAS analyses remain difficult.

  • PFOA precursors degrade fairly quickly and provide increases to total PFOA concentrations up to 40% over experimental time frames (weeks, months), whereas PFOS precursors degrade more slowly and may add more like 2%.

Other chemicals of emerging concern were discussed, with findings corroborating similar past research - that most degrade in soils in reasonable time frames, except a few, which deserve further risk evaluation. Research at Chicago confirms degradation of many trace chemicals in the composting process. But the question of potential ecological impacts of mixtures of trace contaminants comes up still, occasionally; the argument that seems to address this relates to bioassays, for example, the fact that microbial communities in soils appear to respond favorably to biosolids additions, and they are some of the most-highly-exposed ecological receptors, as Sally Brown noted.

Speaking of soil microbes: several presenters provided eye-opening research. Ian Pepper reported on the literature review and summary he is preparing in response to concerns in the November 2018 EPA Office of Inspector General (OIG) report…

more soon…