Composting in Colorado

Learn about your options for diverting organic waste and using finished compost

Resources for public and private entities

The following information is pulled from the Colorado Department of Public Health & Environment (CDPHE)

​

• Original sources
• Statewide organics management plan
• Colorado organics diversion study
• Colorado Organics Infrastructure Toolkit

​

• Additional sources linked on referenced slides

​

​

*Focus is on municipal solid waste (yard and food waste) only

Sources used for this presentation

Why divert organic waste?

• Reduces food insecurity
• Food donation programs provide people in need with food that would otherwise be discarded.

​

​

• Saves water
• Adding compost to soil increases infiltration, effectively absorbing more water than soil alone.

​

​

• Extends landfill lifespan
• Diverting waste slows the flow to landfills, extending their lifespan.

​

​

• Avoids generation of greenhouse gas (GHG) emissions
• Diverting organic waste to composting and anaerobic digestion reduces emissions from methane and nitrous oxide, GHGs far more potent than carbon dioxide.

Why use organics end products?

End products can be used at any scale by a range of end users (home gardeners, agricultural businesses, governments, and more)

​

• Compost
• A valuable soil amendment and proven effective in sequestering carbon.
• See Marin Carbon Project

​

• Mulch
• When used as a protective layer for soil, it helps keep water from evaporating, protects the soil from erosion, suppresses weed growth, and helps to shade soil from direct sunlight.

​

• Biochar
• A carbon-rich char made from burning organic matter (often wood chips) in a low oxygen environment.
• Spongelike property allows it to trap water and nutrients, provides habitat for beneficial microorganisms, and can help bring soil pH levels to a range more productive for plant growth.

1 - Organics collection & sorting

There are many ways to collect organics from the municipal solid waste stream, and limit and remove contamination.

Photo by Nareeta Martin on Unsplash

Organics collection

& sorting

COLLECTION METHODS

• Curbside
• Door-to-door/yard pick-up
• Block pick-up
• Drop-off location
• Shared container
• Depot/transfer station drop-off
• Centralized compost

​

SORTING ORGANICS

• Contractual policies
• Education & outreach
• Technologies & mechanisms

​

There are many ways to collect organics from the municipal solid waste stream, and limit and remove contamination.

Collection methods

Hauler pickup services

• Curbside
• Hauler picks up from their customers’ curb (or alley)
• Door-to-door/yard pick-up
• Hauler knocks on each door or goes into each yard
• Block pick-up
• Waste generators bring waste to a pick-up point on their block at a specified time.

Drop-off services

• Drop-off location
• Designated drop-off locations accessible during business hours
• Shared container
• Designated drop-off locations accessible at any time
• Depot/transfer station drop-off
• Waste dropped off directly at depot or transfer stations
• Centralized compost
• Waste dropped off directly at the composting facility

Collection methods evaluation

Sorting organics

Sorting infrastructure and mechanisms reduce contamination in organics streams

Common contaminants:

• Plastics
• Microplastics: virtually invisible in unfinished compost, largely impossible to remove from finished compost, can end up in food crops
• Glass
• Produce stickers
• Treated wood
• Tools
• Metals (staples, etc.)
• Unaccepted products marked as “compostable”
• Accepted materials determined by compost processor

Sorting organics

Contamination Management Hierarchy, International Solid Waste Association

Sorting organics - reduce contamination

Contractual policies

• Require haulers to:
• Reject & tag contaminated waste

AND

• Educate WGs on contamination

​

• Municipal buyback programs

Education & outreach

• Physical materials
• pamphlets, bin tags, stickers, posters

​

• In-person education/workshops

​

• Utilize media publications
• radio, tv, websites, social media, etc.

Other mechanisms

• Provide tools to consumers
• food scrap containers, compostable bags, etc.

​

• Sorting technologies
• post-collection technologies, best option case-dependent

2 - Colorado-specific processing considerations

Organics processing technologies and considerations in regions with unique landscapes, climates, and industries.

Colorado-specific processing considerations

PROCESSING TECHNOLOGIES

• Anaerobic digestion
• Composting
• Biochar

​

COLORADO-SPECIFIC CONSIDERATIONS

• Woody materials
• Overstock of materials
• Tourism-based economies

​

Organics processing technologies and considerations in regions with unique landscapes, climates, and industries.

Processing technologies

• Anaerobic digestion (EPA)
• Breaks down organic waste to make biogas (methane + CO₂) that can be burned for energy
• When done properly, emits little to no methane and reduces the need for fossil fuels
• Currently not commonly used for managing municipal organic waste in Colorado

​

• Composting (USCC)
• Breaks down organic waste into carbon dioxide (CO₂)
• Releases only very small amounts of methane and nitrous oxide
• Finished compost can replace chemical fertilizers, helping reduce GHG emissions

​

• Biochar (IBI)
• Charcoal-like, carbon-rich material made by heating organic waste (wood scraps, manure, food waste, etc.)
• Helps soil retain water and nutrients, and absorb pollutants and certain gases
• Its properties vary depending on the specific feedstock and production process

Colorado-specific considerations

Regional, seasonal, and industrial challenges and suggested best practices

​

​

• Large quantities of woody materials
• Regions with arid climates and high altitudes may generate large amounts of woody materials

​

​

• Overstock of materials awaiting processing
• May result from seasonal feedstocks (i.e. yard wastes), culled biomass from wildfire mitigation, and food waste in tourist areas

​

​

• Tourism-based economies
• These communities experience surges in solid waste generation during their popular seasons

Large quantities of woody materials

• Mulching
• Prevents erosion: protects soil surface from rainfall impact & slows overland flow of runoff for better absorption
• Piles need close monitoring to mitigate fire hazard

​

​

• Biochar Production
• Soil amendment: increase water retention, prevent nutrient loss from fertilizers
• Fairly nascent industry, production subject to CDPHE regulations

• Composting
• Requires precise moisture levels, carbon-to-nitrogen ratio, adequate solids, and structural porosity
• Feedstocks, end use, startup costs, permitting, and composting method are all variable

Overstock of materials

• Tourism-associated feedstocks
• Surges in food waste need proactive measures, otherwise that waste will be landfilled

• Seasonally generated feedstocks
• Yard waste and leaves: do not rot, so can be stockpiled or ground into mulch-sized particles
• If ground before storing, temperature should be closely monitored to minimize fire hazard

• Biomass from wildfire mitigation efforts
• Culled biomass can be challenging to deal with, especially with many efforts in rural areas
• Turning into mulched material on the ground provides more opportunity for fire suppression
• But can also increase fire duration and intensity

Tourism-based economies

• Ski resorts
• National Ski Areas Association Sustainable Slopes pledge (signed resorts)
• Industry is very proactive in managing waste; have set best practices

​

​

• Events & Festivals
• Draw large crowds and creates lots of food waste. Many have waste management plans in place
• Plans and waste audits should be part of wider pre-event organizing

• Parks, Wildlife areas, Outdoor attractions
• In 2023, there were 7.8 million visitors to CO state parks
• Limited info exists on best practices for food waste diversion in parks
• NPS launched an ongoing study in 2020 to evaluate existing waste management practices & identify best practices

3 - Establish organics processing infrastructure

State and local organics diversion regulations: Types, current locations, & considerations for future processing facilities locations

From Colorado Organic Infrastructure Toolkit, CDPHE

Establish organics processing infrastructure

STATE-LEVEL ORGANICS DIVERSION REGULATION

• Facility types
• Permitting
• Exemption

​

​

LOCAL ORGANICS DIVERSION REGULATION

​

​

TYPES OF PROCESSING FACILITIES

• Conditionally exempt facilities
• Class I
• Class II
• Class III

​

​

LOCATING ORGANICS PROCESSING FACILITIES

​

State and local organics diversion regulations: Types, current locations, & considerations for future processing facilities locations

State-level regulation

Organics management is primary regulated by the CDPHE Hazardous Materials and Waste Management Division (HMWMD)

​

• Facility types
• 2014 made new facility types & ability to process more low-risk material with less regulatory burden

• Permitting
• Joint effort between local (county & municipal) governments and the state
• Solid waste facility permits in CO are Certificates of Designation (CD)
• Each local governing body holds a CD permit (Class III)

• Exemption
• Facilities with a small capacity and limited feedstock are exempt from CD permit requirements.
• Instead, they must meet minimum permitting requirements (Class I & II)

Local regulation

Colorado is a “local control” state

​

• Discretion given to local governments for decisions that impact them.
• Ex: CD requirements set locally

​

• US Composting Council’s Model Zoning Template and Guidelines
• Baseline ordinance language to help municipalities establish their own

​

Types of processing facilities

4 main facility classes, each can accept certain types of waste (feedstock) & volume capacities

Types of processing facilities

Facility classes determined by size & type of feedstock accepted. Classes that accept MSW are:

Existing facilities (map)

• CESQ facilities are distributed across the Front Range, Mountains, and Western Plains

​

• Class I & III facilities are near population centers, esp. Front Range & Western Slope
• Class I facilities mostly in the Front Range

​

• 43 out of 60 counties do not have a single compost facility that accepts off-site MSW

​

• Counties outside the Front Range
• Have only 1 facility: high population densities, little land available, difficulty with transportation
• Seems there is a minimum population that would justify a compost facility

​

• Facilities by region: Front Range: 25, Mountains: 9, Western Slope: 12

​

​

Map of recommended locations for new facilities, by county

4 - Implement policies that enable organics infrastructure

Policies that support organics diversion and an evaluation of their costs, benefits, and feasibility in Colorado.

Implement policies that enable organics infrastructure

OVERVIEW OF POLICIES THAT ENABLE ORGANICS INFRASTRUCTURE

• Breakdown of current policies

​

​

STATE ORGANICS DIVERSION GOALS

​

​

Policies that support organics diversion and an evaluation of their costs, benefits, and feasibility in Colorado.

Policies

overview

Existing policies by category and application, in place in Colorado or not yet established here.

State organics diversion goals

CO’s 2016 Integrated Solid Waste Management Plan recommended statewide MSW diversion goals

• The goals are for recycling and organics combined
• The latest reported diversion progress data is from 2022

5 - Access to funding opportunities

Potential funding sources to support development of organics collection, contamination reduction, and processing infrastructure

Access to funding opportunities

GENERAL INFO

• Background

​

​

KEY FUNDING TAKEAWAYS

• CDPHE grants
• Subsidized low-interest loans
• Federal funding
• Coordinated regional planning
• Further guidance

​

Potential funding sources to support development of organics collection, contamination reduction, and processing infrastructure

Funding opportunities

• Opportunities exist to establish small & on-farm compost operations at a fraction of the up-front cost and risk of a new Class III permit.

​

​

• A 2021 USCC whitepaper found startup costs to be between $500,000 – $2,000,000 not including land.

​

​

• Traditional bank loans can be difficult to secure because of the high price tag and unfamiliarity with the compost industry among lending institutions.

Key funding takeaways

CDPHE FUNDING

• The Colorado Circular Communities (C3) Enterprise has ongoing grant opportunities
• STEPS Program offers technical assistance and support services

​

​

SUBSIDIZED LOW-INTEREST LOANS

• Can help when traditional bank loans are difficult to secure.
• The Colorado Small Business Development Center (SBDC) provides information on loans and other resources for small businesses.

​

Key funding takeaways

VALUE IN COORDINATED REGIONAL PLANNING

• Coordinated regional planning helps to make the best possible use of funds with the limited availability in CO for new organics recycling infrastructure.

​

​

NO FUNDING DATABASES, BUT ONE LIST

• There do not appear to be any state-specific funding databases for organics management.
• The EPA lists food system funding opportunities, including from other federal agencies.

​

​

GUIDANCE ON FUNDING MECHANISMS

• USCC offers guidance on funding mechanisms on their Business of Composting site

6 - Assess benefits of organics landfill diversion

Benefits of organics end products and landfill diversion and resulting greenhouse gas savings, water savings, & landfill usage avoided from organics diversion

Assess benefits of organics landfill diversion

OVERVIEW OF BENEFITS

• Benefits of organics end products
• Benefits of organics landfill diversion

​

​

​

CALCULATING BENEFITS

• Tons of GHG emissions avoided
• Gallons of water saved
• Cubic yards of landfill space saved

​

Benefits of organics end products and landfill diversion and resulting greenhouse gas savings, water savings, & landfill usage avoided from organics diversion

Benefits of organics end products

*benefits to soil

​

COMPOST

• Valuable soil amendment; proven effective in sequestering carbon
• Marin Carbon Project: shows significant improvement in amount and quality of forage & carbon sequestration

​

​

MULCH

• Helps shade soil from direct sunlight
• Keeps water from evaporating
• Suppresses weed growth

​

​

BIOCHAR

• Traps water and nutrients, provides habitat for beneficial microorganisms
• High pH makes it effective at remediating mine sites where acidity is an issue
• Can be added to low-pH soils to help bring into pH range more productive to plant growth

Benefits of organics landfill diversion

• REDUCE FOOD INSECURITY
• Donation programs redirect food that would be discarded from businesses & individuals to those in need.

• AVOID GENERATION OF GHG EMISSIONS
• In addition to CO2, landfill organic waste emits methane (CH4) & nitrous oxide (N2O); both cause significantly more global warming than CO2.
• Diverting to composting and anaerobic digestion reduces these emissions, resulting in a net reduction in GHG emissions vs landfilling.

• SAVE WATER
• Adding compost to agricultural soil allows higher water retention ability.

• EXTEND LANDFILL LIFESPANS
• Reducing food waste/promoting donation and processing organics send less material to landfills.

Calculating benefits

TONS OF GHG EMISSIONS AVOIDED

• EPA Waste Reduction Model (WARM): If overall tonnages of diverted organic MSW are known, use:

Avoided GHG emissions (metric tonnes of CO2e) = Diverted organic MSW (US tons) x 1.0^c

​

​

GALLONS OF WATER SAVED

• To estimate water saved by diverting organic MSW and using the compost on farms:

Avoided water use (gallons) = Diverted organic MSW (US tons) x 1,163*

*Midpoint water savings estimate

​

​

CUBIC YARDS OF LANDFILL SPACE SAVED

• Assuming waste composition = 28% food, 69% yard, 3% paper (contamination losses accounted for):

Avoided landfill space (cubic yards) = Diverted organic MSW (US tons) x 3.4

7 - Educate key stakeholders

Resources and considerations for developing an education program in Colorado to support organics landfill diversion.

Educate key stakeholders

CONSUMER AND RETAIL FOOD WASTE PREVENTION

• Example education programs

​

​

COLLECTION PROGRAM COMMUNICATION PLAN

• Conduct a communications assessment for new commercial and residential collection programs
• Implement universal best practices for a communications plan
• Sector-based communications best practices

​

​

INCENTIVIZING A CLEAN ORGANIC DISCARDS STREAM

​

​

CERTIFIED COMPOSTABLE PRODUCTS

​

Resources and considerations for developing an education program in Colorado to support organics landfill diversion.

Consumer & retail food waste prevention

Ongoing engagement and education must be a priority for all waste diversion programs; using multiple education tactics will likely bring the most success.

​

​

​

​

​

​

​

​

​

EPA’s Wasted Food Scale

Collection program communication plan

• Conduct communications assessment for new collection programs
• Identify: audience, info to be shared, timeline
• Utilize communication tools and strategies already in use
• Assess efficacy, gaps, opportunities for improvement

​

• Implement universal best practices
• Use multiple methods, consistency in messaging & frequency, simple communications
• Clearly differentiate bins for organics, trash, recycling bins
• Provide guidelines, collection schedules, and FAQs

Sector-based best practices

RESIDENTIAL SECTOR

• Separating yard debris from other organics (due to its bulk) may be a best first step.
• Consider easing into organics collection by including food scraps
• Some already compost at home; Credit them for being proactive and assure they can continue.
• Collections programs can supplement by providing diversion for problematic home composting items.

​

​

COMMERCIAL, INSTITUTIONAL, AND LARGE MULTI-FAMILY SECTORS

• Tailor on-site guideline signage by business type & types of organic materials generated there.
• Implement a mechanism to spot check materials at pickup to track guideline adherence.
• Leave a notification if overly contaminated or improperly sorted.
• Track collection data, including contamination levels

Incentivize clean organic waste stream

• Removing post-consumer contaminants is far more difficult than with traditional recyclables
• Contamination levels are difficult to quantify and express (e.g. plastic film)

​

​

• Best practices are continually evolving due to the complexity of separating packaging & other inorganic material from wet organic material.

​

​

• Suggested incentivization methods:
• Maintain consistent messaging; always include why diversion is important
• Adjust the message based on audience
• “Close the loop” by incentivizing the use of finished compost

Certified compostable products

• Standards For Products Represented As Compostable aims to clarify confusion over which packaging and products can be composted
• Requires if “compostable” is on a label or product, it must be certified compostable.
• Disallows use of confusing terms like “biodegradable” or “made with plants”

​

​

• Compostable packaging, bags, or other products must be Biodegradable Products Institute (BPI) or Compost Manufacturing Alliance (CMA) certified

​

​

• If certain compostable products aren’t allowed, it can be helpful to include education on the benefits of reusing items

Resources

Helpful resources and next steps

Colorado resources

Colorado Dept of Public Health & Environment (CDPHE)

• Statewide Organics Management Plan & Infrastructure Toolkit
• Composting information
• Hazardous Materials and Waste Management Division (HMWMD)
• Colorado Circular Communities (C3) Enterprise
• Program overview
• Funding opportunities
• STEPS (public sector assistance)
• Private sector assistance - NextCycle & CEDC

​

​

OTHER

• Front Range mulching guidelines
• Colorado Composting Council
• Recycle Colorado
• EcoCycle Clean Compost Campaign Toolkit
• National Ski Areas Association Sustainable Slopes initiative
• Existing composting facilities (map)
• Map of recommended new locations for facilities

​

Colorado organizations, policies, and resources

General resources

FEDERAL RESOURCES

• US Composting Council
• What is compost
• Financing Industrial Composting Facilities whitepaper
• EPA
• Wasted Food Scale
• Composting info
• Anaerobic digestion info (basics)
• Local and regional resources

​

​

TOOLS & RESOURCES

• ReFED Food waste solution providers directory
• Closed Loop Partners contamination management
• Marin Carbon Project (research on compost & soil)
• International Biochar Initiative (IBI)

​

Federal, nonprofit, private, other organizations and resources

Funding opportunities

COLORADO

• Colorado Circular Communities (C3) Enterprise grants
• STEPS program
• Office of Economic Development & International Trade (OEDIT)
• Colorado Small Business Development Center (SBDC)

​

​

FEDERAL

• EPA Recycling Education and Outreach
• EPA Climate Justice Community Change
• EPA food system funding opportunities
• USDA Composting & Food Waste Reduction cooperative agreements

​

State and federal

Thank you!

​

​

​

Dani O’Connor

info@recyclecolorado.org