Key Takeaways from Day Three at WasteExpo 2019
Here's a look at the panel sessions and key takeaways from day three of WasteExpo.
WasteExpo 2019 sessions for day three focused on contamination, single stream versus dual stream recycling and maximizing organic waste diversion. Here is a look at some of the key highlights from some of the most notable panel sessions of the day.
In a session called “Single Stream vs. Dual Stream,” Willie Puz of the Solid Waste Authority of Palm Beach, Fla.; Anne Germain of the National Waste & Recycling Association; and Louie Pellegrini of the Peninsula Sanitary Service shared their take on which of the two collection systems is best and why. Moderated by Rachel Oster of Diversion Strategies, this presentation also shed light on special considerations to get the cleanest stream beyond simply going with single or dual stream.
Marin County in California began segregating at the curb in the 1980s—even sorting what is still one of the most problematic materials—glass, recalled Pellegrini, who has served the region for decades. Then in the 1990s, single stream became the trend, where all materials were tossed in one bin, adding a convenience factor for residents and haulers.
Peninsula Sanitary Service collects and processes materials to prepare them for market. “The way we do it is with a split collection vehicle and split cart in a dual stream collection. Fiber is on one side, and bottles, cans and glass are on another side,” said Pellegrini.
He gets more commodity value than single stream tends to because materials come out cleaner.
“We have sent materials directly to paper mills. Glass breaks, but they are larger pieces and can be color sorted,” he said.
Pellegrini doesn’t get high value for glass. But the California regions he services have a bottle bill, “so we have to collect glass; it’s not going to go away in California,” he said.
His cost to implement a dual stream automated collection system is 21 cents per household.
Single stream collection yields at least 20 percent residuals while dual stream yields about 10 percent. Pointing out proponents of the latter system, the issue appears to be that with single stream, people toss more in the bin that doesn’t belong there.
However, challenged Germain, contamination is not just about the bin system. Key to participation for a successful program of any kind is to understand what has to be done for success.
“If you go to single stream and have robust education, would material become as clean as with dual stream?” asked Germain.
Among reasons she believes contamination is often high with this system is “wishcycling,” where people toss items in the bin not knowing if they can be recycled, hoping they can be.
Mandatory participation also leads to increased contamination—some if forced won’t make the effort, especially if they don’t understand why they should follow the rules.
Pay-as-you-throw, where people are charged less for recycling more and for throwing less in the trash, contributes too, she pointed out, commenting, “When people run out of room, they have used recycle bins as trashcans.”
Meanwhile, she said some communities running single stream programs with robust education have 8 to 12 percent contamination.
When dual stream is utilized, she said, automated systems with split vehicles (more than one compartment) are most efficient. Though haulers should be aware they will get less material and have higher costs.
Palm Beach County in Florida has done dual stream for 20 years, other than in the city of Lake Worth. But the city recently transitioned to dual stream.
Solid Waste Authority of Palm Beach County, which delivers the service, offered Lake Worth a 50/50 revenue share on commodities. At the time, the municipality was having to pay $85 per ton to have materials taken away.
Like Germain said of single stream, education with dual stream was key.
The authority developed news releases, and the city’s newsletter carried the same message about the pending change. Sandwich board street signs and billboard ads were also utilized. Stickers were put on each cart; ads went out in the community paper and the authority produced videos explaining how to recycle.
Residents originally objected to the change, but that didn’t last long, said Puz. Prior, the city had a 20 percent contamination rate, which has since dropped to 5 to 7 percent.
“It’s been a great partnership and success story of a city going from single to dual stream,” said Puz.
Still, what works best depends on what a community wants and what it’s prepared to do, according to some recycling experts.
Germain referred to a city in Japan that actually separates waste into 34 categories. It has an 81 percent recycling rate. They can’t do curbside recycling; instead, they operate a central facility.
“They seem happy with their process. But those who add more materials need to have a flexible system that can manage them,” she said.
In “Maximizing Organics Waste Reduction and Diversion,” Veronica Pardo of California Refuse Recycling Council (CRRC), Eric Herbert of Zero Waste Energy, Kimberly Scheibly of Marin Recycling & Resource Recovery and Terry Keene of Keene Environmental Consulting discussed, among topics, what an ambitious bill will mean for California’s waste professionals and up-and-coming technologies to maximize diversion.
California’s SB 1383 passed in 2016 but is in the rulemaking period. It’s got the state’s solid waste industry talking about demands and big changes it’s already having to prepare for.
The bill calls for a 50 percent reduction in organic waste from 2014 levels by 2020 and 75 percent by 2025. That equates to 20 million less tons of organics disposed than today, said Pardo.
“An earlier bill defined organic waste as food waste and yard waste. But SB 1383 is a different animal because now anything that creates methane is defined as organic waste. Now, we are looking at textiles, paper and lumber, so it’s a huge change,” she said.
The expectation is that these materials will be tracked and sampled. As the bill reads now, jurisdictions also would be required to have standardized cart colors to distinguish waste types. As currently proposed, the bill also would require haulers to identify generators that are contaminating and to have a system to go back to them to resolve.
The bill imposes an obligation on jurisdictions to procure compost and renewable natural gas. There has been an attempt to expand the definition to include renewable electricity, Pardo told event attendees.
CRRC members are concerned about whether the industry can handle the volume of materials driven by the policy.
“Only a quarter of facilities in California can accept food waste now. Only 4 million tons of capacity are available. California needs an additional 20 million tons capacity by 2025,” said Pardo, who anticipates a steep learning curve as the industry tries to adapt.
“We know how to do green waste, but with food, you deal with odors and [other management issues],” she said.
CalRecycle has tentative plans to hold its next workshop in mid-June, and the regulatory language should be presented then. Then, there will be a comment period.
“We continue to have conversations around siting, permitting and funding streams for not just traditional food waste but paper, pulping and other materials. Meanwhile, the regulations are expected to begin in 2022. So, we are not that far away,” said Pardo.
Herbert talked about several technologies to divert organics. These are not low-cost solutions, but increasingly, they are perceived as valuable, especially by entities looking to offset their carbon.
"Customers say, 'we want this,' or waste companies say, 'I can differentiate myself by diverting organics from mixed waste,'' said Herbert.
He described a few technologies, including advanced mixed waste processing to segregate materials and prepare them for an automated process. A system running 100 tons an hour would require only 16 human sorters.
Herbert also touched on advanced in-vessel composting. This process, when combined with another system, receives material in one end, which is turned and moved to the opposite end. Then, it’s postprocessed with screens. “You can take paper and organics and have a finished compost in 21 days, which is the best we’ve seen,” said Herbert.
Another technology involves making an engineered fuel, which can be burned in industrial environments like cement kilns. In California, these plants must reduce emissions now or buy carbon credits, so this is a good application, he said.
Hebert provided diversion figures for each of these technologies: 15 to 25 percent for advanced mixed waste systems, 25 to 45 percent for compost (when compost and anaerobic digestion are combined it’s higher) and 20 to 40 percent for engineered fuel (or solid recovered fuel).
Moving forward, he projects, “We will be seeing a lot of automation involving robotics, optics and screening, which are meeting market demand well. They require less human labor, get higher throughputs, are cost effective and yield high-quality products.”
Marin Recycling owns and operates a number of facilities, including a recycling center that processes 250,000 tons annually. It has made a concentrated effort to mitigate contamination.
“We do a lot of education and outreach. We learn from best practices—tools that work. And we ask what didn’t work to not repeat mistakes,” said Scheibly.
It’s important to know your customer base, she told event attendees. “Learn their behaviors because this will affect composition of feedstock.”
Marin Recycling has done focus groups, talking to property owners and multifamily and single-family residents. And the company did a waste characterization study to see what was thrown away. A third of it was organics.
What’s especially key to making organics collections work, she said, is to have an outreach coordinator and a lot of communication.
“Some of our outreach staff have worked in restaurants and are aware of backend functions and can give advice like how to lay out their kitchens,” she said.
She left attendees with this final message: “It’s important to engage in training and retraining and collect and inspect and repeat. If you do that, you will have successful programs. If you continue the process routinely, your result is really clean feedstock.”
Keene Environmental Consulting recently did an organics diversion feasibility study for Philadelphia, the sixth largest municipality in the country, which disposes 1.3 million tons a year.