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Greening the Cannabis Industry

Overview

The cannabis industry's growth and processing of hemp and marijuana have numerous environmental impacts. The Colorado Department of Public Health and Environment is working to raise awareness and establish best practices for the industry to reduce its environmental footprint.
The right resources, innovative strategies, greener business practices, and industry awareness will result in an eco-friendly, sustainable, and renewable industry that will flourish for generations.
The new Environmental Sustainability Report from the National Cannabis Industry Association provides environmental Impacts, best management practices, policies.

Cannabis Grow Operation

Marijuana businesses are also regulated by the Marijuana Enforcement Division.
Hemp Cultivators are also regulated by the Department of Agriculture.

Growing cannabis emits volatile organic compounds, commonly referred to as VOCs. Marijuana-Infused Product (MIP) facilities or hemp extraction facilities also emit volatile organic compounds from solvent extraction processes. Volatile organic compounds from the cannabis industry contribute to ozone formation in Denver's ozone nonattainment area. To reduce their air quality impacts, we have recommended best management practices for both grow and Marijuana-Infused Product facilities.

Marijuana-infused product facilities and any cannabis facility that uses a process boiler or generator may be subject to air pollutant reporting and permitting depending on annual emissions.

Colorado’s marijuana sector heavily relies on electricity to run artificial lights, air conditioning, and dehumidifiers. Electrical generation is responsible for a large portion of greenhouse gases and other air pollutants, so energy efficiency impacts air quality in Colorado.

The first step to improving your energy usage is tracking your usage and establishing a baseline.

The Colorado Energy Office officially launched the Colorado Cultivators Energy Management pilot program in January 2020 in partnership with local electric cooperatives and municipal utilities. The program was designed to provide eligible cannabis cultivation businesses with no-cost technical energy use assessments to better understand energy use drivers and cost-effective energy management opportunities.

The cannabis industry produces a variety of waste streams, some of which may be subject to specific requirements under the Colorado Solid Waste Regulations and the Colorado Hazardous Waste Regulations. Each facility is responsible for complying with these regulations and determining appropriate waste management strategies, including making hazardous waste determinations for each waste stream.

Hazardous wastes generated by these facilities may include, but are not limited to, spent organic solvents and refining chemicals, used reactants, compressed gases or aerosols, bulk or residual fertilizers, cleaning solutions, and universal wastes (mercury-containing lighting, ballasts, batteries, etc.).

​Marijuana and marijuana-related waste disposal
  • Compliance Bulletin - waste guidance policy​
Hemp and hemp-related waste disposal
Effective 1/1/21- Summary of New Marijuana Waste Handling Rules

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    Recorded webinar on Marijuana Composting Regulations in March 2021 

Indoor grow facilities rely on the municipal water distribution system for influent irrigation and wastewater collection system for effluent discharge. Influent filtration and treatment can be necessary for crop optimization, which results in energy consumption and waste generation.

If wastewater is sent through a sanitary sewer system, the sewer provider needs to know the type of discharge coming from the grow facility to ensure they can handle treating that contaminant.

If wastewater is not sent through a wastewater treatment plant via a sanitary sewer system, other options for wastewater treatment must be evaluated. For the domestic portion (e.g., toilets, sinks, showers, laundry), an on-site wastewater treatment system may be appropriate. An on-site wastewater treatment system might be permitted either under the local on-site wastewater treatment system program (if the design capacity is 2,000 gpd or less) or the Water Quality Control Division through the site application/discharge permit process (if the design capacity is greater than 2,000 gpd).

For non-domestic wastewater (e.g., hydroponic water, wastewater with plant food, or fertilizers), there are several options depending on the type and quantity of wastewater generated, but the permitting entity is dependent on the selected method of discharge or waste handling. The options for industrial (non-domestic) wastewater discharges and the appropriate entity for coordination are:

  • Discharge to the sanitary sewer 
    • Contact the specific sanitation district.
  • Discharge to surface water
  • Discharge to impoundment 
  • Discharge to containers/vault and then pump and haul to a facility for discharge.
    • Note: Contact the receiving facility. There may be a waste generator and/or tank issues depending on the waste, so should also coordinate with Hazardous Materials Waste Management Division through the technical assistance line at 303-692-3320.
  • Discharge using beneficial use 
  • Composting materials
  • Disposal at a landfill after mixing with soil or other absorbent material
    • Contact the receiving landfill to confirm the resulting mixture can meet its waste acceptance criteria prior to disposal at the landfill.
  • Discharge to a septic system or other underground injection if approved by the U.S. Environmental Protection Agency, Underground Injection Control program 
    • Contact Omar Sierra-Lopez at EPA Region 8 regarding permitting. 
    • Note: This includes a septic system that combines industrial (non-domestic) wastewater with domestic wastewater. If there is a non-domestic on-site wastewater treatment system at the site, EPA may also evaluate the domestic on-site wastewater treatment system during their review/permitting.
    • An on-site wastewater treatment system is appropriate for easily digested organic material and settleable solids similar to household domestic wastewater. An on-site wastewater treatment system consisting of a tank and soil treatment area without additional treatment is not the appropriate treatment for high strength and many other wastes. EPA will require appropriate treatment for the particular wastewater.

The discharge and appropriate permitting also depend on the type of operation for cannabis grow facilities. For example, a discharge permit is not needed for a greenhouse situation with gravel floors where water is applied to plants in a single use, and minimal water drips from the plants to the gravel. In contrast, a hydroponic operation trying to waste a water solution concentrated with nutrients and other constituents would definitely be non-domestic and handled consistent with the list above.

Please coordinate with the local public health agency and the permitting entities identified above when considering options.
Water quality considerations go beyond specific discharges. Inefficient water use is wasteful and can damage facilities by encouraging fungal growth, creating worker air quality safety hazards, and adding extra load to the HVAC system, wasting energy.

To contribute towards a greener industry, please use the resources below. To discuss innovative strategies and collaboration, contact cdphe_apcd_sbap@state.co.us.

Watch a video on the CDPHE Cannabis Environmental Assistance and the Environmental Leadership program.