Jimena Baldino spends part of every week checking dumpsters — or rather, the relatively new green compost bins that sit next to dumpsters in Aspen’s alleys.
She stands on tiptoe to lift the huge, heavy metal latch and peek in the bear-proof containers.
“I can tell from looking at the bags how it’s going,” said Baldino, the city of Aspen’s waste diversion and recycling specialist. So far, the compost program looks like a success.
In October, the city of Aspen implemented the first stage of its February 2023 organic waste-diversion ordinance, which requires any business with a retail food license to divert food waste from the landfill. In practice, this means that all restaurants and catering companies working within the city limits need to compost any organic waste.
Data collected at the landfill shows that the amount of food waste coming into the compost section of the landfill increased by 70% in the first four months of this year, which includes many restaurants’ busy ski season, compared to the same period in 2023. The year-to-date increase is 54%, which reflects the fact that many restaurants close in May and early June.
“It’s huge,” said Cathy Hall, Pitkin County’s solid waste director. “And that’s all from Aspen’s ordinance.”
Keeping food waste out of the landfill is beneficial not only because it helps to preserve space in the rapidly filling dump 8 miles downvalley from Aspen, but because it keeps that food from rotting under layers of other trash and turning into methane, a highly potent greenhouse gas.
In Pitkin County, diverting food waste and other organics — meaning, anything that was, at one point, alive — out of the landfill has the potential for a big impact. A 2022 waste sort showed that compostable organic waste made up 33% of municipal, household trash; on the commercial side, compostable organics accounted for 38% of trash.
Hall attributes the near-doubling of compost coming into the landfill to the 104 businesses in Aspen’s city limits that now fall under the compost requirement, most of which are restaurants. Some started compost programs before last fall’s deadline, but most are new to the process.
With the busy summer season underway, Baldino and the city’s Waste Diversion and Recycling administrator, Ainsley Brosnan-Smith, have started visiting and revisiting local restaurants to ensure that composting is underway.
“We’re pretty confident the majority of every restaurant is participating in this program,” Brosnan-Smith said. Last winter, she said, every business in town that falls under the ordinance was composting.
Brosnan-Smith and Baldino say it’s their job to facilitate the process and create buy-in.
“We don’t think the fine or ticket system is helpful for success,” Baldino said. “It’s about education.”
That means training restaurant workers — in English and Spanish — on the ins and outs of composting and also explaining why composting matters and the difference it can make in the community.
“(We) try to make them have more buy-in personally so they know they’re contributing to a really positive effort that’s helping the environment,” Brosnan-Smith said.
A 2020 community greenhouse gas emissions inventory showed that 16% of Aspen’s total emissions come from the landfill. According to the U.S. Environmental Protection Agency, “wasted food is responsible for 58% of landfill methane emissions.”
The compost process allows the carbon and nutrients from food and other organic waste to return to the soil and support new plant growth. It not only eliminates emissions from the landfill, but can positively support a healthy ecosystem.
“Compost is the best diversion; everything stays local,” Hall said.
Local process retains nutrients, extends landfill life
Aspen’s ordinance doesn’t explicitly require businesses to compost, instead mandating food-waste diversion through “recoverable management” practices. Other options for food waste mentioned in the ordinance include donation and animal feed. The de facto result is that restaurants are turning to compost, and there is one hauler, EverGreen ZeroWaste, that currently collects commercial food waste in Aspen.
The local company has a near-monopoly on compost hauling in the region; Hall said EverGreen brings in about 95% of food waste that is composted at the landfill.
When food waste comes in, it’s mixed with wood chips and other yard waste, and with biosolids, the solid organic matter leftover after wastewater is treated.
As the organic material breaks down, the compost piles reach 140 degrees. The compost cooks at that high temperature for up to 30 days, then it is moved off the engineered compost pad to cure for three months.
The high temperatures in the compost process destroy weed seeds and reduce pathogens. Before the compost is finished, it’s tested for fecal matter, salmonella and persistent herbicides. Hall said the compost processed at the landfill consistently meets or exceeds state standards.
“We have no contamination — very clean compost,” Hall said.
State requirements now also require compost facilities to screen for PFAs, a group of human-made chemicals that are resistant to heat, water and oil and are known as forever chemicals because they do not break down.
“We find PFAs in the biosolids, but below state levels of concern,” Hall said.
The Pitkin County Landfill recently invested in an $875,000 new machine that screens, cleans and tests compost three times faster than in the past, which Hall said will not only help address the growth in the compost program at the dump, but increase efficiency. Last year, the landfill composted about 18,000 tons of organics and resold about 6,000 tons.
“That’s pretty standard,” Hall said. The organics lose weight as they break down and cook in the compost process, and some efficiency is lost when the compost chunks together into large pieces known as “overs,” which aren’t sold in the final product.
The new equipment will help process and break down those larger chunks, and Hall hopes to increase efficiency to about 50%, so that the landfill would sell about half the weight of the incoming compost product.
That final product is sold to landscaping companies and gardeners to complete a local cycle, one of the benefits of a compost program at the Pitkin County Solid Waste Center.
Another is extending the life of the aging, nearly full landfill as the county works on a major expansion. Hall estimates that the current space has about five more years of life before it runs out of room for trash.
Engineers are working on plans to double the size of the landfill, which also recently completed a smaller expansion in a ravine to the north of the original site. In the next round of expansion, the landfill would extend to the south, and Hall estimates it would accommodate 70 years of trash. Engineers are on track to submit plans to the state in the fall, and Hall expects another two years of review before any potential approval.
An expansion would probably include more space for composting as the program grows. The area requires an engineer-designed, 20-inch clay pad that prevents liquid byproducts of composting from seeping into and contaminating groundwater. Those liquids are diverted into a stormwater catch basin, where they evaporate.
Programs work to keep contamination out of compost
The idea of compost is simple: Anything that was once alive goes into the compost bin. But it’s also essential that everything else stays out. Because of the risk of contamination ruining the process, Hall said she’s not convinced that forcing people to compost is a good idea.
“I’m not a big proponent of making people do it,” Hall said. “You’ve got to want to compost because it has no tolerance for contamination, so you really have to want to do it.”
Hall said A1, a major Front Range compost processor, has had its program nearly ruined with contamination when cities started requiring residential compost.
Baldino and Brosnan-Smith, Aspen’s waste diversion team, agree that preventing contamination and creating buy-in are essential, even as their job demands that they enforce the city’s law.
Baldino uses a light touch when she visits restaurants to see if they are complying. If she sees contamination, she says, she starts with a conversation.
“We see if they are maybe in need of more materials or more trainings, or maybe they just don’t fully know how to approach it,” Baldino said. “It’s not like we are going to just go ticket someone if there’s trash in the compost.”
Instead, Baldino and Brosnan-Smith help restaurants set up best practices, such as having easily accessible trash cans for things such as plastic gloves and bags — the most frequent contaminants — next to the compost bins. They also check in at least twice a year with each restaurant in town, since many employ seasonal workers, so the staff might need frequent training.
“All the turnover — that’s really hard for restaurants to keep up,” Baldino said. “Sometimes we go to kitchens and they have a whole new team every other month. They do their best, they try to keep up and train them, but we know it’s a struggle.”
So far, the city has not issued any tickets for violating the terms of the waste-diversion ordinance, but Baldino said they work closely with EverGreen ZeroWaste to keep tabs on restaurants that might need extra support. Haulers issue additional charges when there are contamination issues.
For now, there haven’t been major issues with contamination at the landfill’s compost pad, and Hall credits the haulers’ diligence.
“EverGreen ZeroWaste is really good with education, (and) they screen their loads. If they see a dumpster with a problem, they’ll go talk to the people that are using that dumpster,” Hall said. If they see too much contamination, the load could end up in the trash.
Alyssa Reindel, CEO of EverGreen ZeroWaste, said she relies on her team of collection drivers to remove contamination so that “each collected truckload of material has made its way to the compost pad to be processed.”
She credits drivers and city of Aspen staff for following up with any customers with repeated contamination issues.
“If there are persistent contamination or wildlife safety concerns that haven’t been resolved with initial communications, then we may add a small fee to inspire change,” Reindel wrote in an email. “Overall, people want to do the right thing, and composting is relatively simple in regards to what we can and cannot accept, resulting in an impressive amount of clean compost collected.”
Bears present a big challenge
As the waste-diversion works through its second high season of required composting, there is one challenge they didn’t have to think about in the winter: bears. Aspen’s alleys have long attracted bears looking for a quick meal, and Baldino is mindful of the feast that sits beneath the lids of the outdoor compost containers.
“It’s scary for us to know that all the food waste is in one spot,” she said.
The city spent $150,750 to provide restaurants with bear-proof, steel containers with a complicated latching mechanism that automatically locks. There are four different sizes, from 65 gallons to 3-yard dumpsters, and so far, there have been no reports of bears breaking into alley compost bins.
“We’ve seen containers on the ground because bears tried to get in, but the latch system is working,” Baldino said, so that the container doesn’t open even when it has been toppled.
Brosnan-Smith said the city purchased enough containers for all local restaurants, plus some extras to replace any that break, and they have proven worthy in keeping out bears. The department is considering extending the same financial support to multifamily housing complexes in the next round of the ordinance’s implementation.
Once compost gets to the landfill, the bears lose interest.
“It’s not appealing to them,” Hall said.
At the compost pad, food waste is mixed every night with wood chips and sewage sludge, a far-less-enticing meal than what can be found in the trash.
“Every once in a while, there’ll be like a watermelon from Whole Foods tempting them in, but the trash is a better meal for them,” Hall said. “If they can get a burger out of trash, it’s a tastier meal, I guess.”
In the next several years, Aspen aims to keep more and more of those burgers out of the landfill. The waste-diversion ordinance has three phases; for now, only restaurants and other businesses with retail food licenses (such as the hospital and the Food & Wine Classic festival) are required to compost. In January 2026, the rule extends to include all commercial businesses and multifamily housing, and finally, in January 2028, everyone in the city of Aspen will need to get on board with composting.
Both Pitkin County and the city of Aspen support Aspen Journalism with community nonprofit grants. Aspen Journalism is solely responsible for its editorial content.
This Aspen Journalism original story was published in the July 14 edition of Aspen Daily News.