Composting is the way of the future; it’s the best method for keeping food waste out of landfills and reducing methane emissions that have drastic climate repercussions. But composting can be difficult when you don’t have the space or time to create your own backyard compost pile. The good news is that if you live in Denver, Colorado, curbside composting is coming your way — and sooner than expected. 

In March of 2025, the city of Dever is launching its compost service, which will be available to the entire city.  It’s all happening nine months earlier than it was initially planned for, and if you live in Denver you can now opt-in (although it’s not required).  In some parts of Dever, the service is already available and underway. If you’re hoping to understand what you’ll be able to compost in Denver and where and when you can do it, read on to get the low down. 

Understanding Denver’s composting program

According to the EPA, composting is the next best thing you can do with uneaten food after feeding people or feeding animals that feed people. So while composting isn’t mandatory for Denver residents, the city is trying to incentivize participation with a "Pay-As-You-Throw" (PAYT) policy, implemented in 2023. The program requires residents to pay for trash services based on the size of their trash cart — small carts, of course, cost the least.

The three trash cart sizes — small (35 gallons), medium (65 gallons), and large (95 gallons) — are priced incrementally to encourage downsizing waste. Keeping your food and organic waste out of these trash bins means you can downsize your trash cart at any time if a large cart is no longer needed. Recycling and composting services are included in the program at no additional cost (previously, there was a cost for compost collection). This PAYT policy is part of Denver’s sustainability goals and is in place to help the city achieve a 50% waste diversion rate by 2030. 

The PAYT policy replaces the city’s previous flat-rate trash collection system. To ease the transition, the city provided rebates for low-income households, as well as resources on how to maximize recycling and composting.

While composting isn’t mandatory for individual residential properties in Denver (you simply opt in to the program), composting is mandatory for Denver businesses, restaurants, and apartment complexes. If you live in an apartment complex in Denver, you should check with your building’s manager to understand your responsibilities as a resident. 

How to start curbside composting in Denver

If you live in Denver, you can check this map from the city’s official website to learn when curbside composting will become available to you. If you don’t have access to composting services yet, you can expect to receive  a letter in December 2024 that will notify you about when services will start.  

Once you get the letter, you can choose between a 65 or 95-gallon composting bin (called a “cart” in Denver), which will be provided to you free of charge by the Trash, Recycling, and Composting Department of the Mile High City. If you don’t receive a letter, you can log into your Denver Utilities account to select a cart. 

After you receive your cart, let the composting begin! You can place all your compostable materials in your composting cart and then just leave the cart out with the trash on your usual collection day. As with the trash, just make sure the composting cart is out by 7 a.m. on your collection day and no earlier than 7 p.m. the evening before. 

What can I compost in Denver?

Knowing what you can and can’t compost is an essential first step in the composting process. Adding anything that isn't compostable to your green bin will contaminate the bin and redirect its contents to the landfill. If you’re new to composting, knowing what you can and cannot compost may take a little bit of forethought, but once you get the hang of it, the process will become second nature. 

The general rule? Food scraps and plant trimmings belong in compost, and everything else belongs in either recycling or trash. Food scraps cover a broad array of materials, but in general, it’s things like fruit and vegetable trimmings and cores, bread, meat, poultry — including bones — and pretty much anything you’ve cooked or ordered for takeout. You can find a full list of what’s accepted on the city's official website. 

As for what not to compost — things like paper products, tea bags, diapers, pet waste, paper towels, take-out containers, and even other containers labeled “compostable” cannot be composted in your compost cart. (Note that this is different from what’s allowed in other cities like San Francisco or Seattle. Take care to abide by the local regulations to avoid contaminating your compost!) And although things like sod, dirt, and mulch might seem like yard trimmings, they also cannot be composted. 

Compostable materials can all be deposited directly in the compost cart. However, if you’d prefer to collect them in a compost bin in your kitchen first, you can use a compostable bag so long as it’s been approved by the Composting Manufacturers Alliance (CMA).

Make composting easier with Mill

Whether you live in a district of Denver with composting services in full effect or are still waiting, an easy way to begin creating your own compost at home is by recycling your food scraps with Mill. The Mill food recycler can process everything from apple cores and banana peels to chicken wings (bones included) and stale bread. Mill turns food waste into Food Grounds that can then be added to your backyard compost pile (if you have one!), sent to curbside pickup,  or used right away as a nutrient-rich soil amendment. Plus, it dehydrates and dries the grounds, keeping your kitchen free of fruit flies and unpleasant smells.

Sources:

1. City and County of Denver: “Compost Rollout.” https://www.denvergov.org/Government/Agencies-Departments-Offices/Agencies-Departments-Offices-Directory/Recycle-Compost-Trash/Compost/Compost-Rollout

2. United States Environmental Protection Agency: “Composting.” October 10, 2024. https://www.epa.gov/sustainable-management-food/composting

3. City and County of Denver: “DOTI Affordability Rebate Programs.” https://denvergov.org/Government/Agencies-Departments-Offices/Agencies-Departments-Offices-Directory/Department-of-Transportation-and-Infrastructure/Programs-Services/DOTI-Rebates

4. City and County of Denver: “How to Compost.” https://denvergov.org/Government/Agencies-Departments-Offices/Agencies-Departments-Offices-Directory/Recycle-Compost-Trash/Compost/How-to-Compost

5. A1 Organics: “Compost Manufacturing Alliance: Compost Approved.” https://a1organics.com/acceptables/