May 31, 2016
Reporting from the Canadian Biosolids & Residuals Conference
As notorious fires burned northward in Alberta’s oil patch, about 100 leading Canadian biosolids professionals gathered in the provincial capital, Edmonton, for the 2016 Canadian Biosolids and Residuals Conference. This event happens every two years; Vancouver hosted the 2014 conference.
On Tuesday afternoon, May 17th, early-arriving attendees toured the Edmonton Waste Management Centre. The 576-acre site hosts eight recycling and resource recovery operations, a transfer station, a materials management research and development facility, and a closed landfill (with leachate treatment). Most impressive are the advanced recyclables sorting facilities, one of which produces standard recyclable commodities – plastics, paper, cardboard, glass, and metals – from single stream consumer-sorted recyclables. In a second large building, mixed municipal solid waste (MSW) is received and sorted, and organics (food scraps) are removed. The final, non-recyclable product from this mixed MSWtreatment process is “garbage fluff,” a loose mix of plastics and paper rich in carbon. Starting recently, this garbage fluff is being processed in a pyrolysis facility owned and operated by Enerkem Alberta Biofuels. The City expects this use of otherwise nonrecyclable MSW to boost the City’s diversion rate from about 50% to near 90%. The Enerkem facility produces methanol, and will be able to produce ethanol in the future.
Municipal organics (e.g. food scraps) and biosolids compost operations are important parts of the Waste Management Centre. Residential and business organics are not source-separated, but are removed in the initial trash sorting process at the Centre and sent to composting. Open lagoons store biosolids, when needed, until they are sent to land application or are dewatered and composted. Next to these lagoons is the new, full-scale, 10-tonne-per-day phosphorus extraction plant operated by Ostara; Edmonton piloted this process starting in 2007. An anaerobic digestion facility, with combined heat and power use of the resulting biogas, is planned and should be operational in 2017 - 2018.
The conference sessions on Wednesday and Thursday, May 18th and 19th, focused on advances in beneficial uses of biosolids. Mike Van Ham and Mark Teshima of Sylvis Environmental, the leading biosolids management company in western Canada and a major sponsor and participant in the conference, highlighted recent coal mine reclamation, the science of how biosolids improve soils and crops, and the development of advanced biosolids projects that solve environmental problems. Scott Gamble described Calgary’s integrated biosolids and source separated organics composting facility.
Other sessions looked at expanding beneficial use through energy production (including Sally Brown of the University of Washington discussing switchgrass ethanol with biosolids), advances in technology (thermal hydrolysis, advanced digestion), and nutrient recovery (e.g. struvite removal and other side-stream treatments).
Public engagement was a popular topic, with the interest driven in particular by the current public conflicts around biosolids use in British Columbia, which started with a poorly-designed and –operated biosolids composting program in Merritt in the Nicola Valley region. John Lavery of Sylvis provided a sobering summary of “The Perfect Storm” that is taxing the social license for biosolids operations in that province. Sarah Mason, PhD candidate at Western University in Ontario, released her most recent data on public attitudes around the Lystek biosolids processing facility in Dundalk, ON, comparing local attitudes today, after the facility has been operating, to local attitudes at the time of planning and permitting.
NEBRA, with members in eastern Canada, was well-represented at the conference. Board members Andrew Carpenter and Lise LeBlanc - both agronomic experts – spoke on mitigation of greenhouse gas emissions through biosolids recycling and the resurgence of the Halifax biosolids recycling program after vociferous public upset, respectively. NEBRA staff Ned Beecher described the critical role of communications and communications networks like NEBRA and NW Biosolids (which also has Canadian members).
But research was the major focus of the 2016 CBRC, and Canada hosts some of the most useful and practical studies on biosolids utilization being conducted anywhere. Calgary reported on five years of data regarding the levels of emerging substances of concern (ESOCs, aka microconstituents) in its biosolids. Gordon Price of Dalhousie Univ. in Nova Scotia summarized field research on land applied alkaline-treated biosolids. He started the work in 2008, and it is currently focused on ESOCs and their potential impacts to soil organisms. Ann Huber of Soil Resource Group described use of industrial residuals to remove nitrogen, phosphorus, and pathogens from runoff. Greenhouse gas emissions from Alberta’s biosolids management practices were reported by Kentson Yan.
To cap it all off, Lynda McCarthy of Ryerson University presented the two hugely significant projects her team has completed over the past several years:
· a literature review assessing the potential risks associated with land application of biosolids in the Canadian context – including the best summation to date of our understanding of ESOCs (microconstituents) in biosolids (a critical current resource – download it), and
· extensive bioassays to determine impacts from a typical Ontario biosolids land application process on both terrestrial and aquatic biota.
This literature review and the bioassay work by this Ryerson team directly address the most critical questions of current biosolids debates: Do the myriad trace chemicals in biosolids have any significant impacts? How about pathogens? Dr. McCarthy's answer lies in an email she recently sent to a leading Canadian environmental organization, which she shared at the conference: "If you do not have time to deeply mine the literature, I can help direct you to peer-reviewed studies... whose weight-of-evidence suggests that, when observing municipal and provincial regulations and guidelines, land-application of municipal biosolids is a sound and sustainable strategy."