Clinton Sander is done with contaminated compost.
On a recent morning, he sifted through long piles of waste from Denver and Boulder at a facility in Keenesburg operated by A1 Organics, the state's largest compost recycler.
Sander, the company's marketing manager, scanned for inorganic objects scattered throughout the heaps of yard waste and food scraps. Common culprits include adhesive fruit stickers and plastic knives, but glass bottles were at the top of his most-wanted list. Each one could break into shards small enough to evade the company's industrial screening machines and make it into the final product: a nutrient-rich soil amendment sold to local gardeners and landscapers.
"That's dangerous. If there's a load with a smashed bottle, we're going to reject it and it will be brought to the landfill," Sander said.
It only took a few seconds to find a trash bag containing seltzer bottles and a glass food container in one pile from Denver.
The problem has grown more severe as Front Range communities expand their compost programs, Sander said. A1 Organics has pushed city waste officials to take action for months, but it drew a line in the sand in early August. The company now inspects all incoming truck loads of compost and rejects any with unmanageable levels of contamination. Any amount of glass can trigger the company to reject a tractor-trailer load of compost, Sander said.
A1 Organics has diverted about 25 to 30 semi-truck loads to landfills due to contamination over the last six weeks, charging waste haulers a $500 fine plus the additional disposal fees. Sander suspects many waste management companies are now taking loads straight to the dump to avoid the penalty. He said the company has seen a 40 to 50 percent decline in incoming loads since the contamination policy went into effect.
The policy is already forcing changes in Colorado’s most climate-minded cities. Boulder recently announced it would stop enforcing part of an ordinance that requires compost bins in all restaurants.
While Sander said compost contamination is a nationwide problem, he worries the situation could worsen as Colorado communities expand organic waste services. Starting next year, Denver plans to launch a new program to expand residential composting by providing free curbside compost bins to every household. He thinks the city’s composing push could succeed, but only if the city carefully monitors its waste stream and educates the public.
"Together, we can fix this. We can make it work," Sander said.
Colorado struggles to keep organic waste out of the dump
Compost is a proven strategy to support soil health and combat climate change.
In landfills, organic waste emits a heavy dose of methane, a greenhouse gas 80 times more potent than carbon dioxide during its first two decades in the atmosphere. Industrial compost facilities allow food and other organic waste to decay in the presence of oxygen, cutting those emissions. The resulting fertilizer also boosts crop yields and helps trap climate-warming carbon underground.
Colorado has long struggled to waste less and recycle more.
From 2018 to 2020, the state's recycling and composting rate dropped from 17.2 percent to 15.3 percent, far below its goal of 28 percent by 2021, according to data from the Colorado Department of Public Health and the Environment. Federal reports show the nation’s average recycling rate is around 32 percent.
Denver is one city trying to boost those numbers. In June, the city council approved a new "pay-as-you-throw" program, which will require single-family homes and small apartment buildings to pay for trash pickup based on the size of their bin. The new trash fees will be offset by free compost and recycling bins that will be delivered to all customers throughout 2023.
A1 Organics currently processes waste from more than 30,000 of Denver’s compost customers. The company has not yet rejected any loads from the city, opting to work with city officials to improve its overall waste stream to avoid unacceptable contamination.
Due to the company’s concerns about contamination, Vanessa Lacayo, a Denver Department of Transportation and Infrastructure spokesperson, said the city recently launched a public education campaign to teach people about proper composting through community events, mailers and online advertising.
"These efforts will ramp up as we head into 2023 when we begin phasing in composting services to all customers," Lacayo said.
If residents can't properly separate waste, they could face a penalty under the upcoming free compost program. The new ordinance allows the city to fine residents $500 to $999 for contaminating compost or recycling bins with trash.
Boulder scraps a food scraps program
A1 Organics' new zero-tolerance policy has had a much more immediate effect in Boulder.
The company has helped with public campaigns to battle compost contamination in Boulder for years. In July, A1 Organics informed the city's two largest waste haulers — Eco-Cycle and Western Disposal — about its plans to inspect and reject incoming compost loads.
Both waste haulers quickly sent letters to customers, warning any additional expenses due to contamination could be passed along as fees. Kathy Carroll, the community relations manager for Western Disposal, said her company identified restaurants as a major source of contaminated compost, especially ones with public-facing compost bins at stations where customers sort their own trash and table scraps.
"Once you give up any real control over monitoring those bins, you're going to have problems," Carrol said.
Boulder requires all homeowners and business owners to sign up for compost service under a Universal Zero Waste Ordinance first enforced in 2017. The city has cited the policy as one reason it now boasts one of the state’s highest composting and recycling rates, diverting 53 percent of its waste from landfills.
Under the same law, restaurants must provide customers with three clearly labeled bins for compost, recycling and landfill waste. Businesses submit an annual form with pictures of their customer-facing waste set up to ensure compliance.
At the onset of the COVID-19 pandemic, the city stopped requiring restaurants to demonstrate compliance as they struggled with the sudden loss of in-person dining. The requirement was restored at the end of August.
Less than two weeks later, the rule is on an indefinite hiatus due to A1 Organics’ new contamination policy. On Tuesday, the city announced it would allow restaurants to remove compost bins in restaurants and dining areas.
Jamie Harkins, a Boulder climate policy advisor focused on waste issues, said the city now recognizes it's too confusing for customers to sort single-use waste cups and utensils in dining areas. While many objects appear compostable, they could add to the contamination problem.
"We're just going to keep learning as we go and try to get to that reusable, circular future that we're all dreaming about," Harkins said.
The city has no plans to require photos of customer-facing compost bins going forward. Instead, Harkins said Boulder will explore ways to encourage restaurants to use washable plates and cups and regulations to reduce single-use plastic. That way, customers are less likely to be in a position to toss a disposable fork in the compost bin.
Avery Brewing Company is already trying those strategies at its Boulder taproom and restaurant. The establishment only provides ceramic plates and metal silverware. Servers offer compostable straws upon request. Washable cups are stacked at outdoor water stations.
Jocelyn Durocher, a manager and member of the brewery's sustainability team, said the company developed its waste practices with Eco-Cycle, its nonprofit waste hauler. She thinks the brewery’s actions are proof that compost contamination is a solvable problem.
"The reusable cups are not expensive. They hold up really well. You're putting more pressure on your dishwashing machines, but it's totally worth it, in my opinion," Durocher said.
