Compost

Overview

Denver Composts is a weekly collection service for all food scraps, yard debris, and non-recyclable paper. All Denver households (with 7 or less units) are eligible for this program. We send this organic material to a facility that turns it into a soil amendment, known as compost.  By signing up for compost collection you can reduce the amount of waste you throw away by as much as 50 to 75 percent!

Current compost customer count (January 2021):

count_Jan20.jpg

Accepted Items

Food Scraps:

Baked goods, Bones, Bread, Cereal, Cheese, Coffee grounds, Dairy products, Eggs & eggshells, Fish, Fruits, Gravy & sauces, Meat, Nuts, Pasta, Peanut butter, Pizza, Poultry, Processed foods, Rice, Salads, Sandwiches, Spoiled or moldy food, and Vegetables

Non-Recyclable Paper:

Coffee filters, Facial tissue, Greasy pizza boxes, Paper bags, Paper napkins, Non-coated paper plates, Paper towels, Teabags, Small paper items, Plain white tissue paper, Waxed cardboard, and Wax paper

Yard Debris:

Flowers, Grass clippings, Houseplants, Leaves, Plant trimmings, Small branches (no larger than 4 feet in length and 4 inches in diameter), and Weeds

Other Items:

Pet hair, Wooden chopsticks, stir sticks, and popsicle sticks

Compost FAQs

What are the benefits of composting?

  • Composting keeps organic material out of landfills. In a landfill, climate warming gases, such as methane, are made as organics decay under anaerobic (without oxygen) conditions .
  • Methane is 21 times more potent in its heat-trapping capabilities than carbon dioxide.; therefore, the benefits of composting organic material far outweigh the environmental “costs” of collecting, hauling and processing organic material with trucks and equipment that burn fuel.
  • Organic material like food, yard debris and soiled paper makes up about 50% of what Denver residents send to the landfill.
  • The U .S. sent 25 million tons of food waste to landfills in 2005 — the greenhouse gas impact of composting this mass would be the equivalent of removing 7.8 million passenger cars from the road.
  • Composting is nature’s way of recycling and returning valuable organic matter and nutrients to the soil to be used again. It can be used for gardens, lawns and even houseplants, to conserve moisture and add nutrients to help plants thrive.
  • Incorporating compost into the soil can help to increase the soil's ability to retain moisture and reduce the need for fertilizers, herbicide or fungicide on farms, gardens and landscaping.
  • Compost increases infiltration and permeability of heavy soils, thus reducing erosion and runoff.
  • Compost can retain 100% of its weight in water and is an important component of gardening in a drought.

How do I manage odors or pests around my green compost cart?

Compostable material does have a smell. It’s the same stuff you put in your garbage, but now it’s just in a different container.  Odor is often caused by too much moisture. You can minimize odor by:

  • Ensuring you set your cart out for every collection.
  • Draining as much liquid as possible from organic material.
  • Keeping your cart clean.
  • Burying your food waste underneath some yard debris.
  • Wrapping food scraps with newspaper or placing in a paper bag before putting it in your cart.
  • Freezing leftover meat and fish scraps and waiting to put them in your cart until your collection day.
  • Waiting to clean out your refrigerator until the day before your collection day, rather than the day after. 

The green composting cart is designed to be pest-resistant with thick plastic and a tight-fitting lid. Compost can attract fruit flies, so be sure to keep the lid closed. If you have problems with bugs and rodents around your trash now, you may experience some problems. If you do not currently have problems with pests, you should not experience any additional problems with your green cart.

It is the resident’s responsibility to clean their cart.  A simple rinse with the hose every couple of weeks should keep the cart clean. A great idea for cleaning your green cart is to use a broom to reach the bottom. You may also help keep your cart clean by lining it with newspaper or brown paper yard waste bags.

How do I manage over-sized yard debris?

All branches or limbs placed in compost carts must be no longer than 4 feet in length, no larger than 4 inches in diameter, and no more than 50 pounds per piece.

Logs, stumps, and other larger yard debris  are NOT accepted in the Denver Composts Program.

For information on dropping off larger yard debris materials visit Cherry Creek Recycling Drop-off.

How do I use my kitchen compost pail?

  • When preparing meals or cleaning up after a meal, scrape food preparation scraps and leftovers from your plate into your kitchen pail. You can even include your paper plates, paper towels and napkins.
  • Store your kitchen pail under or in the sink or on the counter to make it easy to access while preparing food or cleaning up after a meal. Find a new spot for your garbage pail so that you have to think before you throw something away - ask yourself, "Can this be composted?"
  • When filling your kitchen pail, remember to include other items in your house that can be composted such as facial tissue, microwave popcorn bags, paper towels, popsicle sticks and all the other things found on the Accepted Items list.
  • Dump the contents of your kitchen pail into your green cart at least once a week.
  • Drain as much liquids as possible from food before putting it in your kitchen pail.
  • Rinse out your pail after you empty it or run it through the dishwasher on the top shelf to keep it clean and fresh. (WARNING: Running your pail on the bottom shelf of your dishwasher will cause the pail's lid to warp and not close properly.)
  • Line your kitchen pail with newspaper or a brown paper bag to help keep it clean. Or, purchase compostable bags to use to line your kitchen pail (see information below).

 

What kind of bags should I use?

Never place any plastic bags in your compost cart.

Plastic is a serious contaminant for composting. At the compost facility, all the compostable material is ground into fine pieces. When plastic is in the mix, we get small pieces of plastic that are hard to remove. Plastic is not compostable and will not break down in the composting process.

Most supermarkets in Denver take back their own bags for recycling, so check with your local store to find out if they accept plastic bags for recycling. Consider using a reusable bag instead. Many stores will give you a 5 cent credit for each bag reused.

Only Brown Paper Bags and BPI Certified Compostable Bags are allowed in the Denver Composts program.

If you choose to buy compostable bags to use in your kitchen pail or green cart, please make sure you purchase the right bags.  All bags used for compostables other than plain paper bags, must carry the official BPI logo (Biodegradable Products Institute) . The BPI compostable logo lets the composting collector and processor know that products with this label have been tested to ensure that they will compost quickly, completely, and safely. Of course, newspaper and paper bags are still an easy way to keep composting cleaner and to save you money. Compostable bags may be purchased online and at some Whole Foods stores and Safeway stores.  Call your local store in advance to see if they carry them.  

Should paper go in the compost or recycling?

Paper materials (such as cardboard, office paper, magazines, and newspapers) that are accepted in the Denver Recycles program should be recycled instead of composted. Although some of these items are compostable in small amounts, it is significantly more environmentally beneficial to recycle paper items.

Paper that is soiled and can't be recycled should be composted, for example greasy pizza box bottoms, newspaper used to wrap fish, or used paper plates (no plastic-coated plates).

Remember that paper plates, napkins, towels and tissues are NOT accepted for recycling in the purple cart but are accepted in the Denver Composts program.

Backyard composting vs. compost collection service?

The organic material collected through the Denver Composts collection program is sent to a commercial composting facility in Keenesburg, Colorado that is run by A1 Organics.  There, organic material is ground into fine pieces by an industrial grinder and then composted under controlled conditions. 

So materials that you wouldn't normally put in a backyard composting bin, such as meat, bones, processed foods, and soiled paper such paper napkins, can break down quickly in a commercial composting facility and contribute to making quality compost.  After composting is complete A1 Organics performs a number of analytical tests on the compost, using an independent laboratory, to ensure the compost is a quality product before selling it.

Denver Recycles encourages you to continue backyard composting if you're already do so. You can still compost lots of materials in your backyard while putting your meat, dairy, grains, and food-soiled paper products, and excess yard waste out for pick-up in your green compost cart.

 

Garbage disposal vs. composting?

There are no real environmental benefits to disposing of food waste through the wastewater system. In fact, it requires extra water usage to do so. Also, food waste can be the source of many plumbing problems. Disposing food waste through a garbage disposal increases the likelihood of clogs, especially if the food waste contains unsaturated fats, which solidify at room temperature and can build up inside pipes.

Placing food items in your green compost cart is a better alternative both environmentally, and for your home. Backyard composting is good too, just not for the meat or fat items.

What happens to compost after collection?

The organic material collected through the Denver Composts program is sent to a commercial composting facility in Keenesburg, Colorado that is run by 
A1 Organics.  There, organic material is ground into fine pieces by an industrial grinder and then composted under controlled conditions, so it can break down quickly and contribute to making quality compost.  After composting is complete,  A1 Organics performs a number of analytical tests on the compost, using an independent laboratory, to ensure the compost is a quality product before selling it.

Denver Recycles offers bagged and unbagged compost for sale back to Denver Residents at a discounted price each year at the Annual Mulch Giveaway & Compost Sale.

It is now easier than ever to close the compost loop and return finished compost made from the materials collected in Denver’s green compost carts back into your soil. Thanks to our partners at A1 Organics and Ace Hardware, bags of Denver’s Own EcoGro™ Compost are now available for purchase at neighborhood Ace Hardware stores.

The finished compost is also sold to farmers and other retailers. If you are interested in purchasing A1 Organics compost, it can be purchased retail from Pioneer Sand and Gravel locations or other local Class I and II Compost Suppliers.

 

Are businesses and apartments eligible for compost collection?

Denver Recycles, a program of the City & County of Denver Department of Transportation and Infrastructure, Solid Waste Management, is only authorized to provide services to residential homes of seven or fewer units and our own municipal facilities. Denver Recycles is not authorized to provide services to commercial properties such as businesses and apartment communities.  Please visit our Apartment and Multi-family Recycling page for information on trash/recycle/compost at these buildings. 

How can I pay via check?

  1. Fill out the payment slip on your invoice and mail it in with your check.
  2. Make your check payable to “Manager of Finance”
  3. Write your account number in the memo line of your check
  4. Send in a stamped envelope to:

City and County of Denver

PO Box 735485

Dallas, TX 75373-5485

My compost was missed, can I get a refund?

If a resident's cart is missed for collection, it is the resident's responsibility to call 311 or and report it so that Solid Waste Management can collect the cart within 24 hours. Missed collections do not qualify for a refund. 

 

Ordering take-out? Here are some composting tips.

  1. Compost all of your food scraps! 
  2. Only 100% paper products can be composted such as paper bowls, plates, and napkins. If there's a plastic lining on the item, it belongs in the trash. Plastic lining makes the paper shiny, whereas compostable paper is usually dull and rough to the touch.
  3. Make sure small plastics (i.e. condiment packets, straws) aren't accidentally thrown in your green cart.
  4. Some restaurants use compostable serviceware. Denver Composts only accepts BPI certified compostable products. These can be cross checked through the Compost Manufacturing Alliance.
  5.  And remember, when in doubt, throw it out! Let's keep contamination out of our green carts.
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Denver Compost Challenge

Did you know? Organic materials such as leaves, branches, grass clippings and food scraps make up almost 50% of what Denver residents send to the landfill each year. In order to meet Denver’s 2020 goal of recycling and composting 34%, we need to recycle and compost 31,000 tons more each year. Together, we can do this.  

Goals:

  • Increase the number of residents composting through the Denver Composts program or other options.
  • Decrease contamination in compost (and recycling).
  • Build community.

Here’s How YOU Can Participate in the Denver Compost Challenge:

  • Learn about the many ways to compost in Denver.
  • Discover the many benefits of composting and the importance of putting compost back in our soil.
  • Choose a method and start composting now!
  • Help us spread the word.
  • Stay plugged in as we measure the impact of our collective efforts.

Stay Connected:

 Ambassadors Toolkit

Join the Facebook Group

Denver Composts Program Participation:

By Neighborhood

Neighborhood December 2020
South Park Hill 42%
Country Club 31%
Wellshire 30%
Hilltop 29%
North Park Hill 29%
Congress Park 27%
Washington Park 26%
Central Park 25%
Hale 25%
Montclair 25%
University Park 24%
West Highland 24%
Virginia Village 24%
Washington Park West 23%
Berkeley 23%
Sloan Lake 23%
Platt Park 22%
Belcaro 22%
Whittier 22%
City Park 22%
Cory - Merrill 21%
Lowry Field 20%
Rosedale 18%
Goldsmith 18%
University 18%
Sunnyside 18%
Skyland 17%
Regis 17%
Washington Virginia Vale 17%
Baker 16%
University Hills 16%
Speer 15%
City Park West 15%
Southmoor Park 15%
Highland 14%
Hampden 14%
Hampden South 14%
Chaffee Park 13%
East Colfax 13%
North Capitol Hill 13%
Clayton 12%
Five Points 12%
Cheesman Park 11%
Cole 11%
Windsor 10%
Harvey Park South 10%
Northeast Park Hill 10%
Bear Valley 9%
Capitol Hill 9%
Auraria Lincoln Park 8%
Harvey Park 8%
Athmar Park 8%
Overland 7%
Villa Park 7%
Fort Logan 7%
West Colfax 7%
Barnum West 6%
Jefferson Park 6%
Cherry Creek 6%
Barnum 6%
Ruby Hill 6%
Civic Center 5%
Mar Lee 5%
Marston 5%
Valverde 4%
Indian Creek 4%
Globeville 3%
Elyria Swansea 3%
Green Valley Ranch 2%
Westwood 2%
College View - South Platte 2%
Montbello 2%
Sun Valley 0%

 

By Council District

Council District July 2020
1 - Councilwoman Amanda Sandoval 18%
2 - Councilman Kevin Flynn 7%
3 - Councilwoman Jamie Torres 5%
4 - Councilwoman Kendra Black 15%
5 - Councilwoman Amanda Sawyer 21%
6 - Councilman Paul Kashmann 19%
7 - Councilman Jolon Clark 13%
8 - Councilman Christopher Herndon 21%
9 - Councilwoman Candi CdeBaca 12%
10 - Councilman Chris Hinds 17%
11 - Councilwoman Stacie Gilmore 2%

Denver Sustainable Neighborhoods

Neighborhood December 2020
La Alma Lincoln Park 8%
Congress Park 27%
Harvey Park 9%
Baker 16%
Barnum 6%
Chaffee Park-Regis 15%
Green Valley Ranch 2%
East Colfax 13%
Greater Park Hill 28%
Highland 14%
Central Park 25%
West Colfax 7%
Villa Park 7%
North City Park (Skyland) 17%

 

Denver's Own EcoGro™Compost

It is now easier than ever to close the compost loop and return finished compost made from the materials collected in Denver’s green compost carts back into your soil. Thanks to our partners at A1 Organics and Ace Hardware, bags of Denver’s Own EcoGro™ Compost are now available for purchase at neighborhood Ace Hardware stores.

 

Composting food scraps and yard debris with the Denver Composts program is good for the environment, and good for Denver.  Denver’s compost collection program is a way residents can keep organic material out of the landfill and help Denver meet its recycling and climate goals. In addition, closing the compost loop and putting finished compost back into Denver’s soil provides an even greater environmental benefit. When added to soil, compost:

  • Improves soil structure and porosity, and encourages root growth
  • Increases soil’s water holding capacity and moisture retention
  • Enables soil to retain nutrients longer and makes nutrients more available to plants
  • Provides beneficial microorganisms to the soil

Here’s what you need to know :

  • Compost is a soil amendment that can be added to soil to provide benefits to plants and increase overall soil heath.  Detailed use instructions are included below and on the back of each bag.
  • Denver’s Own EcoGro Compost is an STA Certified compost product (meets the U.S. Composting Council’s Seal of Testing Assurance).
  • Denver’s Own EcoGro Compost is exclusively available at Ace Hardware stores for $6.99 per bag.
  • Denver’s Own EcoGro Compost contains materials from the Denver Composts collection program and materials from other similar municipal and commercial sources. 

Using Compost:

Application Establishment Maintenance               
Flowers and vegetable gardens Mix 1-2" into the first 6-8" of soil Apply 1-2" to planting area at start of growing season
Lawns Mix 1-2" into the first 6-8" of soil Annually: apply a 1/4" layer before or after core aeration
Trees and shrubs Use 1 part compost to 2-3 parts soil to backfill planting hole Apply 1-2" over soil surface of bed in the Spring or Fall (or both)
House plants Add up to 20% compost into potting mix Spread 2-3 tablespoons on the surface of the potting soil

 

Master Composter Program

Become a Denver Master Composter

The Denver Master Composter Training Program offers Denver residents a unique opportunity to both learn about composting and recycling topics, and to give back to the community through sharing this information with others. Through classroom seminars and hands-on experiences, Master Composter participants study a broad range of topics including the science behind the composting process, compost pile construction, resource conservation, and solid waste management. In return, Master Composters then share this newly acquired knowledge with the greater Denver community by teaching free “Learn to Compost” workshops and participating in outreach events at community gardens, schools and local farmers’ markets.

master composter logoNo experience necessary!

Here’s a little more about how the program works and the level of commitment required:

  • Instruction: Master Composters receive 40 hours of instruction in the science behind the composting process, resource conservation, compost bin construction, vermicomposting, recycling, solid waste management, and community outreach.
  • Service: In exchange for this training, Master Composters are required to complete 40 hours of self-paced outreach between May and October. Please note, outreach opportunities often fall on evenings and weekends, and participants need to provide their own transportation.
  • Dedication, not experience: Master Composters do not need to be experienced composters or gardeners to participate, but participants must be able to commit the time necessary to attend the classes, tours, demonstration sessions, and also complete the 40 hours of outreach.
  • Cost: A $40 fee is required to help cover the cost of program materials. However, an inability to pay the fee should not deter qualified candidates! Under certain circumstances, the fee can be waived.
  • Schedule: Training classes are held on Monday evenings from late February through mid-April. There is also a Friday tour in April as well as two Saturday work days requirements. Outreach hours are self-paced, but must be completed between May and October.
  • Enrollment: Each year, approximately 35 enthusiastic and committed participants are selected for this program.

 Application Information

Backyard Composting

Organic material makes up about 58 percent of what Denver residents send to the landfill every year. These items can be composted, which is the controlled decomposition of organic materials by microorganisms. This process results in compost, a crumbly, earthy-smelling, nutrient-rich, soil-like material.

If your neighborhood isn't part of Denver Composts, or if you'd like to be able to use your own compost in garden and landscape projects, consider backyard composting! Home composting can be as simple as buying a bin and tending it weekly. See the resource guides below to find the method that works best for you.  

Essential Concepts: 

  • Compost contains both carbon and nitrogen sources, which can be simplified as browns for carbon (e.g., leaves, straw, woody materials) and greens for nitrogen (e.g., grass and food scraps). Adequate sources of carbon and nitrogen are important for microorganism growth and energy.
  • Organic materials are broken down through the activities and appetites of various invertebrates that will naturally appear in compost, such as mites, millipedes, beetles, sowbugs, earwigs, earthworms, slugs, and snails. These microorganisms need adequate moisture and oxygen to degrade the organic materials in the most efficient manner.
  • Microbes in the pile create considerable heat and essentially "cook" the compost. Temperatures between 90 and 140 degrees Fahrenheit are common in properly maintained compost piles, but may not reach these levels in backyard compost piles. These high temperatures are necessary for rapid composting as well as for destroying weed seeds, insect larvae, and potentially harmful bacteria. When the compost is finished, it has a crumbly texture throughout the pile.

 

How to Get Started:

  1. Choose a level area at least three feet square (3' by 3'). The area should receive only partial sun. The area can be fenced off, or you can use a pre-manufactured composting bin — see below for a list of bins and vendors for home composting
  2. Open the ground with a pitchfork or shovel approximately an inch or so under your pile area. This allows the soil microorganisms access to the food sources in your compost pile.
  3. Add an alternating mix of four-inch to six-inch layers of finely chopped high carbon and high nitrogen materials. 
  4. To introduce friendly microorganisms to your pile, throw a handful or garden soil on top of the layers. Mix the carbon and nitrogen layers with a garden fork.
  5. Water the layers until they feel like a wrung-out sponge.
  6. Continue building your layers of carbon and nitrogen materials, remembering to throw a handful of soil on top of each layer. Mix each new carbon and nitrogen layer before watering.
  7. Direct sunlight slows the composting process, so cover the top of your pile with black plastic or straw. This also keeps the pile from drying out and slows the loss of soluble nutrients.
  8. Once a week, turn or stir your pile to provide air channels. A spading fork or commerical aerating tool can help with this.
  9. Keep your carbon and nitrogen layers finely chopped, add a little soil, build the pile a minumum of three feet high, maintain the moisture so it's like a wrung-out sponge, and turn it for air. In just two months, you will have your own brown gold compost!

 

Troubleshooting:

If you supply the proper conditions (volume, surface area, moisture, air and variety of materials), you should have little difficulty maintaining your compost system. Occasionally, though, problems occur in any biological system. They usually can be dealt with fairly easily by following these tips:

  • Odors - Odors can be caused by not supplying enough air to the mixture. Turning the pile can help. If the pile is too wet, turn the pile and add extra sources of coarse carbon, such as shredded twigs, alfalfa meal or straw. If there is too much high nitrogen material, add extra sources of coarse carbon as above.
  • Pile doesn't heat - Typically, this is due to a lack of nitrogen material. Mix in high nitrogen sources, such as grass clippings or bloodmeal. The pile also may not be large enough to heat well. In this case, add more material until the pile is at least 3' x 3' x 3'.
  • Center of pile is dry - If the pile is dry, it is not getting enough water. Remember to moisten the pile as you build it.
  • Flies - Flies are attracted to decaying food scraps. Bury food scraps well within the compost pile. Food scraps may also be composted indoors using a ventilated worm box and redworms.

 

Using Compost:

Compost is ready to use when it is dark and crumbly. You should not be able to recognize most of the materials, and it should smell like a damp forest floor.

  • For vegetables, flowers and herbs - Fork it lightly into the soil several times during the growing season. It will conserve moisture, open up air channels in the soil, and slowly release nutrients for your plants.
  • For trees and shrubs - After cultivating the soil at base of the plant, spread an inch or two of compost around the drip line. Leave the area surrounding the trunk free of compost to prevent mice from burrowing there in winter.
  • For lawns - Spread aged compost thinly over newly aerated grass. Eventually, it will help loosen clay soild and allow a healthier, deeper root structure for grass plants. Deeper roots allow plants longer time periods between watering.
  • For houseplants - Enrich potting soils by adding up to 20 percent finely screened compost. Make a good moisture retaining potting soil by mixing finely screened compost, sphagnum peat, and perlite.

Worm Composting:

Worm composting (or Vermicomposting) recruits red wiggler worms to convert our non-meat food scraps into nutrient-rich compost that can be used to improve the health of our yards, gardens and houseplants. See detailed information on How to start composting with worms (PDF).

Worm Compost Vendors

The information below is provided as a service to our residents. This listing of vendors does not imply an endorsement or approval by Denver Recycles or the City and County of Denver. All businesses listed are responsible for complying with all applicable local, state and federal laws.

What to Feed Red Wiggler Worms

In general, Red Wiggler Worms will consume fruits and vegetable scraps as well as the items in the list below.  

  • Fruit, left over vegetable scraps and peelings
  • Coffee grounds, tea leaves and tea bags
  • Vacuum cleaner dust
  • Hair clippings (people and animals)
  • Manures (well aged)
  • Shredded paper such as newspaper and office paper (soak first)
  • Crushed egg shells.

The greater the variety of material used, the better the casting (compost) will be.

Backyard Composting Bins and Vendors:

A composting bin is a great way to control and accelerate your backyard composting efforts. You can build your own or buy a pre-made composting bin.

Local Compost Bin Vendors

Online Compost Bin Vendors

Resources for Building Composting Bins

There are many resources online to help you build several different types of backyard composting bins.


The information above is provided as a service to our residents. This listing of vendors does not imply an endorsement or approval by Denver Recycles or the City and County of Denver. All businesses listed are responsible for complying with all applicable local, state and federal laws