Composting in Denver has gained momentum as a sustainable practice to reduce waste and enrich soil. In 2023, the city expanded its solid waste services, moving to weekly collection for all customers and introducing a new fee structure based on trash cart size. Denver residents can now divert food scraps and yard debris from landfills through the city’s composting program, which transports organic waste to local facilities for processing.

The benefits of composting extend beyond waste reduction. By participating in Denver’s composting efforts, residents contribute to creating nutrient-rich soil amendments that enhance plant growth and improve soil structure. This process also helps combat climate change by reducing methane emissions from landfills.

While Denver’s composting initiative is growing, there’s still room for improvement. Only 13% of Denver households currently compost, putting the city behind national averages. To encourage participation, the city offers guidance, training, and rebates based on income and household size. By understanding what can be composted and how to properly dispose of organic waste, Denver residents can play a crucial role in reaching the state’s diversion goals and creating a more sustainable future.

Fundamentals of Composting

Composting transforms organic waste into nutrient-rich soil. This natural process enhances sustainability and improves soil quality for agriculture and gardening.

What is Composting?

Composting is the controlled decomposition of organic matter. It breaks down food scraps, yard waste, and other biodegradable materials into a valuable soil amendment. The process requires a balance of carbon-rich “browns” (like dry leaves) and nitrogen-rich “greens” (such as food scraps).

Microorganisms play a crucial role in composting. They break down the organic matter, generating heat as a byproduct. This heat accelerates decomposition and helps eliminate pathogens.

Proper composting requires adequate moisture and aeration. The ideal compost pile is damp but not soggy, with enough air circulation to support aerobic decomposition.

Benefits of Composting

Composting offers numerous environmental and agricultural benefits. It diverts waste from landfills, reducing methane emissions and extending landfill lifespans.

The finished compost product enriches soil structure and fertility. It improves soil’s water retention capacity and promotes healthy root growth in plants.

Compost adds essential nutrients to the soil, reducing the need for chemical fertilizers. This supports more sustainable agricultural practices and healthier ecosystems.

Using compost in gardens and farms can increase crop yields and enhance plant resistance to diseases and pests. It also helps sequester carbon in the soil, contributing to climate change mitigation.

In urban areas like Denver, composting creates a circular economy for organic waste. It turns a potential problem into a valuable resource for local agriculture and landscaping.

Setting Up a Compost System in Denver

Denver residents can easily set up a compost system at home. Choosing the right bin, finding an optimal location, and maintaining proper conditions are key steps for successful composting.

Choosing a Composting Bin

Denver offers several options for composting bins. The city provides green compost carts to residents who sign up for the Denver Composts program. These carts are convenient for curbside collection.

For those who prefer DIY options, enclosed bins or tumblers work well in urban settings. They help control odors and deter pests. Open bins or piles are suitable for larger yards with more space.

Consider factors like available space, amount of compostable material, and ease of use when selecting a bin. Many local garden centers in Denver sell various composting containers to suit different needs.

Location and Aeration

Place your compost bin in a sunny spot protected from strong winds. This helps maintain the warmth needed for decomposition. Ensure easy access for adding materials and turning the compost.

Good aeration is crucial for efficient composting. For stationary bins, use a pitchfork or compost aerator tool to turn the contents regularly. This introduces oxygen, speeds up decomposition, and reduces odors.

Compost tumblers make aeration easier with their rotating design. Simply spin the tumbler a few times each week to mix and aerate the contents.

Maintaining Proper Compost Conditions

Successful composting requires a balance of green (nitrogen-rich) and brown (carbon-rich) materials. Aim for a ratio of about 3 parts brown to 1 part green.

Green materials include:

• Fruit and vegetable scraps
• Coffee grounds
• Fresh grass clippings

Brown materials include:

• Dry leaves
• Shredded paper
• Small twigs

Keep the compost moist but not waterlogged. It should feel like a wrung-out sponge. In Denver’s dry climate, you may need to add water occasionally.

Monitor the temperature. A warm compost pile indicates active decomposition. If it’s not heating up, try adding more green materials or turning it more frequently.

Composting Materials

Effective composting requires a balanced mix of materials. Understanding what can and cannot be composted in Denver is crucial for successful waste reduction and soil enrichment.

Green and Brown Materials

Composting relies on a combination of “green” and “brown” materials. Green materials are nitrogen-rich and include food scraps, grass clippings, and fresh plant trimmings. These provide moisture and quick-decomposing nutrients.

Brown materials are carbon-rich and include dry leaves, small branches, and certain paper products. They add bulk and help aerate the compost pile.

A good ratio is roughly 3 parts brown to 1 part green materials. This balance promotes proper decomposition and reduces odors.

Items You Can Compost in Denver

Denver’s composting program accepts a variety of organic materials:

• Food scraps (fruits, vegetables, eggshells, coffee grounds)
• Yard waste (grass clippings, leaves, small branches)
• Uncoated paper products (napkins, paper towels)
• Pizza boxes (free of grease and food residue)

Kitchen scraps like vegetable peelings and fruit cores are excellent additions. They break down quickly and add valuable nutrients to the compost.

Yard waste such as grass clippings and fallen leaves can be composted in large quantities, especially during spring and fall.

Items to Avoid in Your Compost Pile

Certain materials should not be added to Denver’s compost bins:

• Plastic products (even those labeled “compostable”)
• Glass and metal
• Pet waste
• Treated or painted wood
• Dairy products and meat

Compostable products and packaging, despite their name, are not accepted in Denver’s municipal composting program. These items require specialized industrial composting facilities.

Meat, dairy, and oily foods can attract pests and create unpleasant odors. They also break down slowly and may introduce harmful bacteria to the compost.

Home Composting Techniques

Composting at home in Denver is an eco-friendly way to reduce waste and create nutrient-rich soil. Several methods are suitable for different living situations and preferences.

Backyard Composting

Backyard composting is ideal for Denver residents with outdoor space. Start by selecting a sunny spot in the yard and set up a bin or pile. Layer green materials (food scraps, grass clippings) with brown materials (dry leaves, shredded paper) in a 1:3 ratio.

Turn the pile regularly to aerate it and maintain moisture levels similar to a wrung-out sponge. Denver’s dry climate may require occasional watering to keep the compost moist.

Add a mix of kitchen scraps, yard waste, and carbon-rich materials. Avoid meat, dairy, and oily foods to prevent odors and pests. In 3-6 months, the compost will be dark, crumbly, and ready for use in gardens or lawns.

Worm Composting

Worm composting, or vermicomposting, is perfect for apartment dwellers or those with limited outdoor space. Set up a worm bin indoors using a plastic container with air holes.

Add bedding materials like shredded newspaper or cardboard. Introduce red wiggler worms, which are efficient composters. Feed them fruit and vegetable scraps, coffee grounds, and tea bags.

Maintain proper moisture and avoid overfeeding. Harvest the castings every few months by moving the contents to one side and adding fresh bedding to the other. The worms will migrate, leaving nutrient-rich castings behind.

Trench Composting

Trench composting is a simple, low-maintenance method suitable for Denver gardens. Dig a trench 12-18 inches deep between rows of plants or in areas where you plan to plant in the future.

Add kitchen scraps and yard waste to the trench, covering each layer with soil. Avoid attracting pests by burying all food scraps completely. As the organic matter decomposes, it enriches the soil directly.

This method works well in Denver’s climate, as the soil helps retain moisture. It’s particularly effective for composting in vegetable gardens, providing nutrients right where plants need them.

Community and Local Services

Denver offers various composting options for residents, including city-run programs and private services. These initiatives aim to reduce waste and promote sustainability throughout the community.

Denver’s Composting Pick-up Services

Denver Composts, a program run by the city, provides curbside compost collection for a fee. Residents can sign up for weekly pickup of food scraps, yard debris, and other compostable materials. The service costs $9.75 per month, billed quarterly. Participants receive a green cart for their compostables.

Several private companies also offer compost pickup in Denver. Zero Waste Denver and Denver Compost Collective provide subscription-based services with weekly or bi-weekly collection options. These services often include educational resources to help residents compost effectively.

Local Drop-off Locations

For those who prefer to transport their compostables, Denver has multiple drop-off locations. Compost Colorado maintains several sites across the city, including:

• Nude Foods Market in Berkeley
• An alleyway behind Ellsworth and Broadway in Baker
• 1025 East 9th Avenue in Capitol Hill
• Augustana Lutheran Church in Glendale
• JOY FILL in Highlands
• Town Hall Collective on Santa Fe

These locations allow both members and non-members to dispose of compostable materials. Some sites may have specific hours or restrictions, so it’s best to check before visiting.

Denver also organizes seasonal leaf drop events, providing residents with an eco-friendly way to dispose of fall yard waste. These events typically occur on weekends in October and November at designated locations throughout the city.

Environmental Impact

Composting in Denver provides significant environmental benefits by reducing waste, curbing greenhouse gas emissions, and promoting sustainability. This practice helps combat climate change while fostering environmental justice in local communities.

Reducing Greenhouse Gas Emissions

Composting organic materials instead of sending them to landfills drastically cuts methane production. When food scraps and yard waste decompose in landfills, they generate methane, a potent greenhouse gas. Denver’s composting program diverts these materials from landfills, significantly lowering methane emissions.

The city’s partnership with A1 Organics transforms food waste and yard debris into nutrient-rich compost. This process not only reduces emissions but also creates a valuable resource for farmers and gardeners.

Denver’s composting efforts have increased recycling rates and decreased the volume of waste sent to landfills. This reduction in landfill-bound waste directly correlates with lower greenhouse gas emissions from the waste sector.

Composting and Climate Change

Compost plays a crucial role in mitigating climate change effects. It improves soil health, enhancing its ability to sequester carbon dioxide from the atmosphere. Healthy soils enriched with compost can store more carbon, acting as a natural carbon sink.

Denver’s Own EcoGro compost, sold at local ACE Hardware stores, allows residents to contribute to climate change mitigation in their own gardens. This locally produced compost reduces transportation emissions associated with importing soil amendments from distant sources.

Composting also conserves water by improving soil structure and water retention. This is particularly important in Denver’s semi-arid climate, where water conservation is crucial for sustainability.

Promoting Environmental Justice

Denver’s composting program contributes to environmental justice by ensuring equitable access to waste reduction services. The city has expanded its compost collection routes, making the service available to more neighborhoods.

By reducing landfill waste, composting helps minimize the negative impacts of waste management facilities on nearby communities. These facilities often disproportionately affect low-income areas and communities of color.

The program also creates green jobs in waste management and compost processing, providing economic opportunities in the environmental sector. This helps build a more sustainable and equitable local economy.

Education and outreach efforts about composting raise awareness of environmental issues and empower residents to take action in their communities, fostering a culture of sustainability across Denver.

Advanced Topics in Composting

Composting involves complex biological processes and has wide-ranging applications. Understanding the science, using compost effectively, and participating in municipal programs can elevate composting practices.

Composting Science and Microorganisms

Bacteria and fungi are key players in the composting process. These microorganisms break down organic matter, converting it into nutrient-rich soil. Aerobic bacteria thrive in oxygen-rich environments, rapidly decomposing materials and generating heat.

Fungi excel at breaking down tough plant matter like lignin and cellulose. They form networks of filaments called hyphae that penetrate and break apart organic waste.

The composting process goes through several phases. Initially, mesophilic bacteria multiply rapidly. As temperatures rise, thermophilic bacteria take over, killing pathogens and weed seeds. Finally, as the pile cools, diverse organisms recolonize and finish the decomposition.

Using Compost in Gardening and Agriculture

Compost improves soil structure, water retention, and nutrient availability. It acts as a slow-release fertilizer, providing plants with essential nutrients over time.

In gardens, compost can be mixed into soil before planting or used as a top dressing. For potted plants, blend compost with potting soil to improve drainage and fertility.

In agriculture, compost helps restore depleted soils and reduce reliance on chemical fertilizers. It can be applied as a soil amendment or used to make compost tea, a liquid fertilizer.

Compost also supports beneficial soil microorganisms. These microbes form symbiotic relationships with plants, enhancing nutrient uptake and disease resistance.

Municipal Composting Programs

Denver’s municipal composting program, operated by A1 Organics, accepts a wide range of organic materials. Residents can sign up for curbside collection or use drop-off sites.

The program diverts significant waste from landfills, reducing greenhouse gas emissions. Collected materials are processed at large-scale composting facilities using advanced techniques.

Municipal compost is used in city parks, sold to residents, and distributed to local farms. This closes the loop on organic waste, creating a sustainable cycle.

Challenges include contamination from non-compostable items. Education efforts focus on proper sorting to maintain compost quality. The program continues to expand, with goals to increase participation and processing capacity.

Regulations and Best Practices

Denver has specific rules and guidelines for composting organic waste. These regulations aim to reduce contamination and maximize the efficiency of the city’s composting program.

Denver Composting Regulations

Denver’s composting regulations have evolved to address contamination issues. The city no longer accepts used food container boxes, paper products, compostable packaging, or yard waste bags in compost bins. Exceptions include small CMA-certified compostable bags and yard waste during the Leafdrop event.

Residents must use standard-issued containers for compost material. Acceptable items include tree branches, twigs, grass, leaves, shrubs, clippings, weeds, and garden waste. Branches should be cut to fit inside the container.

The city’s pay-as-you-throw program encourages waste reduction by charging residents based on the amount of trash they produce. This incentivizes proper composting and recycling practices.

Best Practices for Denver Residents

Denver residents can optimize their composting efforts by following these guidelines:

1. Sort organic waste carefully, avoiding contamination with non-compostable items.
2. Use small CMA-certified compostable bags for food scraps if needed.
3. Cut branches to fit inside the compost container.
4. Participate in the Leafdrop event for yard waste disposal.
5. Keep compost bins clean and odor-free.

Residents should educate themselves on accepted materials and stay updated on any changes to composting regulations. By following these best practices, Denver residents can contribute to the city’s waste reduction efforts and support a more sustainable community.

Appendix

This section provides key terms and resources to enhance your composting knowledge and practice in Denver. It includes a glossary of important composting terminology and a curated list of additional materials for further learning.

Glossary of Composting Terms

Aerobic: Composting process that requires oxygen to break down organic matter.

Anaerobic: Decomposition that occurs without oxygen, often producing unpleasant odors.

Brown materials: Carbon-rich items like dry leaves, paper, and wood chips.

Green materials: Nitrogen-rich materials such as food scraps and grass clippings.

Humus: The dark, nutrient-rich end product of successful composting.

Microorganisms: Tiny organisms that break down organic matter in compost.

Vermicomposting: Using worms to create compost from organic waste.

Resources and Further Reading

Denver Recycles website: Offers information on citywide composting programs and guidelines.

Compost Colorado: Local company providing composting services and education.

“Composting for a New Generation” by Michelle Balz: Comprehensive guide to modern composting techniques.

Colorado State University Extension: Provides fact sheets and workshops on composting.

Denver Urban Gardens: Offers community composting resources and classes.

EPA Composting at Home: Federal guidance on home composting practices.

Local nurseries and garden centers: Often host composting workshops and sell supplies.