Contaminants in food scrap stream.

March 17, 2016 | General

Tackling Contamination In Food Scraps Stream

Workgroup in Washington State that includes local officials, organics recyclers and food and packaging industry representatives is identifying solutions to contaminant reduction.

Craig Coker
BioCycle March/April 2016
Contaminants in food scrap stream.

Contaminants in food scrap stream. Photo by Nora Goldstein

Contamination of source separated food scraps with noncompostables is a costly proposition — for composting and anaerobic digestion facilities, municipalities and for commercial entities in the food distribution chain. A Washington State-based group of more than 70 municipal officials, composters, regulators, and representatives of various commercial businesses teamed up last year to form an Organics Contamination Reduction Workgroup (OCRW), which is targeting residential single-family and multifamily as well as commercial sources of organics.
“Cedar Grove started composting postconsumer residential and commercial food scraps about 10 years ago,” notes Susan Thoman, a Vice President of Cedar Grove in the Seattle area, and one of the leaders of OCRW. “We thought we could repeat a successful outreach campaign against plastic bags in yard trimmings conducted during the 1990s to reduce contaminant levels in the collected food scraps. Unfortunately, plastics with food scraps did not decrease over time, unlike our experience with plastic lawn and leaf bags did in the earlier days. As a result, we, along with other composters in Washington State, were forced to adopt contamination surcharge fees.” This financial penalty didn’t sit well with the municipalities who had to absorb those pass-along costs from their haulers. “We didn’t want to just throw money at the problem so we decided to work with Cedar Grove and others to see if upstream education and initiatives might make for cleaner feedstocks,” explains John MacGillivray, Solid Waste Program Supervisor in the City of Kirkland (WA).
The stakeholder process got underway with a May 2015 small groups discussion on “Speed Dating for Solutions: Getting Contamination out of Compost” at the Washington State Recycling Association’s Annual Conference. Multiple roundtables of Washington-area composters, haulers, municipal staff, and product users focused on the reality and impact of contamination in compost streams, which served to inspire the formation of the OCRW. Led in part by Thoman, MacGillivray and Sabrina Combs, Recycling and Public Services Projects Administrator for the City of Bothell (WA), the OCRW has met seven times since May of last year.
The first three meetings were held with a process facilitator, Marie Jensen, formerly with the City of Kirkland, and now with the City of Bellevue (WA). Jensen reflects on her role in the initial stages of OCRW: “John [MacGillivray] asked me to help the OCRW get a Mission Statement solidified, goals and objectives identified, and to begin on an Action Plan. What definitely set the tone for the group was their commitment to work together — all sectors were represented. That really made my job easier.” MacGillivray confirms the value of having a facilitator like Jensen. “She helped set the tone that we were all going to collaborate on solving this problem, that we would commit to participating and that we would be respectful of each other and of comments offered.”
The OCRW’s mission statement is to “collaborate to eliminate contamination in organic feedstocks while expanding end products and markets.” In September 2015, the group defined four goal areas and developed objectives (see box on p. 30, Goal Areas) and formed subcommittees to strategize how to meet those objectives.
The Processing subcommittee is focused on learning about technologies for processing feedstocks to remove contaminants (visible in windrows above) and on stimulating markets for compost.

The Processing subcommittee is focused on learning about technologies for processing feedstocks to remove contaminants (visible in windrows above) and on stimulating markets for compost. Photo by Doug Pinkerton

Identifying, Ranking Priorities

Strategizing how to meet these objectives started with an on-line survey to over 75 stakeholders in the greater Seattle metropolitan region. “We wanted to make sure we had input from the widest possible range of stakeholders so we reached out to composters, haulers, generators, municipalities, and large organizations involved in food composting, the food services and packaging industry, and the distribution supply chain,” explains Thoman. The survey had about a 50 percent response rate to questions that asked respondents to prioritize the action items each Subcommittee should take to meet the objectives of that goal area (see box on  p. 32, Top Priorities).
After the Education and Outreach Subcommittee met, their priorities list was modified:
• Segment audience and associate / identify contaminants from each audience — single family residential, multifamily residential and commercial.
• Develop and test common and effective messaging and communication tactics and create a tool kit with tested and recommended strategies to reduce contamination in organics.
• Identify resources to create tool kit.
• Create BMP list to reduce organics contamination for target audiences.
• Prioritize messaging, communication and goals across jurisdictions.
Not surprisingly, several challenging issues face each subcommittee. “One of the primary operational challenges is the efficiencies gained through automated collection which inherently prevents route drivers from viewing and evaluating the contamination levels in the curbside carts,” notes MacGillivray, a leader of the Operational/Contractual/Policy subcommittee. “Also, the contracts between haulers and municipalities don’t have any standardized mechanisms to deal with contaminants. The haulers may or may not have authorization to reject a pickup and enforcement of any contractual requirements has been lax.” Dealing with contamination in curbside carts is also being legally challenged in Seattle. Seattle Public Utilities instructed its haulers to tag carts with warnings where there is clear visible contamination in the carts, and, as a result, is being sued over invasion of privacy issues.

Subcommittee Updates

The Processing subcommittee is led by composters — Edward Wheeler of Lenz Enterprises and Ron Westmoreland of Cedar Grove. So far, subcommittee members have toured both facilities to observe how contaminants are handled and to develop a better understandings of the compost manufacturing processes employed. This subcommittee is focused on learning about technologies for processing feedstocks to remove contaminants and on stimulating markets for compost, primarily in the agriculture sector, but also in the western Washington markets for erosion control, urban low-impact development projects and storm water management. Given the strong focus on source separation in the Seattle region, there is less interest in more separation technology at composting facilities. The Washington State University Cooperative Extension is also working on stimulating agricultural use of compost with field demonstrations (see “Commercial Compost Application on Western Washington Farms,” in this issue).
The Upstream Strategies subcommittee is led by Jenna Higgins, Recycling Programs Coordinator for the City of Kirkland, Gwen Vernon of Cascadia Consulting Group and Susan Thoman of Cedar Grove. “We really wanted to make sure the OCRW understood the realities and limitations of changes in the upstream aspects of food production and packaging so we invited several industry representatives to join the OCRW,” notes Thoman. “We have representatives from multioutlet consumer food service establishments, industrial-scale food distribution companies, compostable plastics manufacturers and institutional food service firms. We learned that food insecurity and food preservation trumps compost contamination in terms of a climate and social issue. Thus, food with plastics is anticipated to grow with more packaging technology being developed to extend the shelf life of food and reduce wastage.”
This subcommittee is also focused on understanding consumer and commercial entity behaviors prior to wastes being placed in the curbside bin. Adds Thoman: “Examples include public food service composting programs where people stand in line to put polypropylene take-out food containers into a compost receptacle because the assumption is it must be compostable, when it is not; or where salespeople are selling customers products like bagasse and poly-lined paperboard as compostable when they are not allowed in Seattle’s program, yet bagasse is used everywhere and looks so much like paper, it is hard for most people to tell the difference; or produce bags purchased at grocery stores that are tinted green that look similar to approved compostable kitchen bags, so food is tossed in them and they go into the yard cart and contaminate the compost streams. Overall, it comes down to two things: behavior and how to define change.” The current focus of the subcommittee is in identifying points along the food production and distribution chain and what the main contaminants, and their sources, are.
The OCRW is meeting bimonthly and hopes to have its work wrapped up in the Fall 2016, and to take its recommendations to regional senior staff and elected officials in early 2017. “In terms of contracts and policy, ultimately the goal is to incorporate what we’ve learned and produced in terms of best management practices as amendments to existing municipal solid waste contracts and into new contracts as they are bid,” explains MacGillivray. “Similarly, we hope that the education and outreach BMPs we develop will be strong and ubiquitous enough to encourage harmonization of messaging across the region.” A future issue of BioCycle will report on the findings and recommendations of the OCRW.
Craig Coker is a Senior Editor at BioCycle and a Principal in the firm Coker Composting & Consulting. He can be reached at

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