After seven years, the Madison, Wis., pilot program for curbside organics collection came to an end due to high rates of contamination.
“What it comes down to for us is that our collection method was basically incompatible with the processing methods,” says Bryan Johnson, recycling coordinator for the city of Madison. “The systems that we have here locally available to us are not terribly resilient to contamination issues.”
The goals of the collection program, which primarily focused on the collection of food scraps, included reducing methane gas emissions when organic material decomposes in the landfill, reducing leachate in the landfill and reducing waste through composting and anaerobic digestion of the organic material, according to the city’s website.
Collection was done with an automated side loader, which meant that whatever was in the cart ended up in the truck. In the beginning, thorough sorting didn’t create a problem because the pilot program’s original composter wasn’t using the material for high-quality compost. When that company went out of business, however, confusion set in. Materials that had previously been OK were now a no-no.
“Everyone else that we could work with here in Wisconsin is trying to make compost they can sell for farmers to use as a soil amendment. That means, obviously, no pet waste and no diapers,” says Johnson. “We had a hard time getting that back out of the system because some of our early adopters missed the mailings and the emails and just kept putting that stuff in there because they were used to a fairly resilient system.”
The program also moved around to different processing partners, which created some confusion as the customer rules slightly shifted with each change. The most recent processor the city was using for the pilot program was a nearby manure anaerobic digester that could handle food scraps. While the company had installed de-packaging equipment, the loads still had to be processed very slowly due to the unwanted materials clogging the screens. Johnson also notes clothing and towels made it into the stream.
“As slow as they needed to work and as much it cost, we never could have gotten bigger. It didn’t make sense for us to keep limping along at that rate, at such a high price, especially knowing that what we have is still contaminated. We need to stop it, fix it or rethink it and see what we can do to actually provide the service because we know how important it is,” says Johnson.
The pilot program wasn’t a total waste. Many important lessons were learned, and the city is weighing options for launching a revamped program with new collection methods and guidelines. “What we have learned here is we have to clean up what we pick up at the curb,” says Johnson.
The rebranded effort would probably just be called a “food scrap recycling” program to provide greater clarity and would likely utilize rear loader collection, with a quick cart inspection at the curb.
In the meantime, home composting presents the best local option for food scraps. “A lot of Madison residents are composting on their own in their backyards. That has been happening even before the pilot, through the pilot and after the pilot,” says Jeanne Hoffman, facilities and sustainability manager for the city of Madison. The city sponsors an event where residents can get discounted bins for home composting.
For long-term planning, Hoffman notes that the city is considering ideas for organic waste management as part of the citywide sustainability planning.
The city uses the landfill in Dane County, which has been capturing methane to create electricity, and now has plans to increase investments in technology that will allow the city to capture the methane, clean it and make it at a grade that is sellable on the market as a gas. Hoffman notes there also have been preliminary conversations between Dane County, the city of Madison and the metropolitan sewage treatment plant about how to manage organics.
“There are some organics heading to the sewage treatment plant as well, and they also have generators onsite that are converting that methane to electricity,” says Hoffman. “There has been some discussion about whether or not they have some extra capacity and whether they could be, in essence, taking on more organics because they already have biodigesters at their facility.”
While the pilot program was a small part of the larger organics strategy for the city, it did have a role to play. As the city looks to restart the program in a new form, Johnson notes the challenges that need to be addressed. For other municipalities interested in running a similar organics collection pilot program, Johnson offers some advice.
“Think about how you are going to provide the service, how you are going to guard against the contamination that you are likely going to see and how you can make it simple enough that everyone can understand what they are supposed to do, regardless of their level of buy in,” says Johnson.