As cannabis use becomes more popular, cannabis commercial waste also increases. Waste can include everything from discarded packaging to gray water to expired products. But perhaps the largest category in terms of tonnage is byproducts and castoff plant material. Because the plant remains federally illegal, strict regulations govern how cultivators and processors may deal with cannabis waste disposal.
Alexandria Irons, founder of Queen of the Sun Grown, an organization that teaches cultivators to utilize holistic growing techniques, knows firsthand about the importance of a proper cannabis waste management plan.
“In a world where resources are finite and soil degradation is at an all-time high, we desperately need initiatives that promote composting and waste reduction,” Irons said. “From excessive plastic plant tags to organic material that can’t be composted and the unnecessary packaging used to market flower, the recreational cannabis market has completely missed the mark on sustainability.”
Cannabis plant waste can be either hazardous or non-hazardous. The two types require different disposal methods.
Non-hazardous plant material includes organic waste like leaves, trim, stalks, and root balls. As long as the elements do not contain measurable amounts of THC and have not been combined with toxic materials, they may be composted, ground down, incinerated, or sent to a facility that handles solid waste.
Cannabis waste management regulations are not clearly defined in all states, but Maine regulations require all plant waste to be rendered unusable before it leaves a cultivation facility. In addition, the waste must be ground and mixed 50:50 with other approved organic waste material like food, animal manure, or lawn clippings.
Not all cannabis plant waste is harmless. Some methods used to extract cannabinoid oils rely on solvents that can produce hazardous waste. Cannabis plant waste that contains extraction agents including methane, propane, butane, and other solvents is considered hazardous waste. In Maine, any waste product with more than 0.3 percent THC must be handled by a licensed waste disposal company or law enforcement.
Irons believes the industry and regulators have a responsibility to do a whole lot more to reduce the damage associated with cannabis waste management.
“There are countless sustainable uses for cannabis plants: leaves could be used as animal fodder, producing fertilizer in the form of manure; stalks could be turned into hempcrete, root balls turned into nutrient rich soil,” she said. “Cannabis has the potential to save the planet, but not within the confines of this profit-driven, over-regulated system that prioritizes profits over patients.”
The following products may be appropriate means for handling non-hazardous cannabis waste.
Brome industrial rotating composter
Seeking a truly industrial-sized composter? Brome’s industrial rotating composter is made for large-scale operations. All stirring of the composting material happens in the rotating drum, which eliminates the need to turn piles with a tractor. This can reduce costs and labor. The composter heats marijuana waste inside the cylinder to 130°F for a minimum of three days, creating the conditions required to reduce pathogens. After curing, the compost can be used as a soil amendment or in other ways.
Vivosun tumbling composter
Composting cannabis plant waste is one way to reduce the industry’s carbon footprint. By taking advantage of compositing, cultivators can turn trimmings and root balls into soil amendments that can improve the overall quality of soil. Vivosun’s tumbling composter is dual-chambered and offers an efficient way to produce high-quality compost. Operation is hands-free, and the device has adjustable vents for quality air circulation.
Bokashicycle culture mix
Bokashi is a Japanese term that translates to “fermented organic matter.” Bokashi relies on fermentation to break down organic waste, while composting relies on aerobic bacteria. Bokashicycle offers a waste disposal value pack that includes 25 pounds of culture mix — enough to process one ton of cannabis plant waste.
JWC Environmental shredder
JWC Environmental offers a shredder that handles both cannabis and non-cannabis material. The equipment allows cultivators to skip the mixing step and quickly grind cannabis into a combination that is at least 50 percent non-cannabis waste. According to the manufacturer, the shredder is “a great alternative to wood chippers that are loud, can only be used outside, may get damaged or clogged by rocks and other debris, and can’t handle wet waste.”
Uline lockable trash can with wheels
When cultivators hire cannabis waste management companies to haul off unneeded plant material, they need a secure method to store that material between pick-ups. Uline offers a lockable trash can with wheels that opens 270 degrees. It was designed to work with automated collection systems.
Grainger waste labels
Waste labels may feel like an afterthought in cannabis production, but they are crucial to avoiding hefty fines related to mismanagement of waste. According to Clark Hill, a law firm known for its work with the cannabis industry, some of the most common cannabis-related Environmental Protection Agency violations are due to improper or inadequate documentation or disposal of plant waste. Many companies offer waste labels, including Grainger. Some states levy hefty fines for improper labeling, and repeated violations can lead to loss of a business license.
Cannabis Waste Management: FAQs on Disposal, Sustainability, and Compliance
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What is considered cannabis waste?
Cannabis waste includes discarded plant material, packaging, expired products, and byproducts from cultivation and processing. This waste can be categorized as hazardous or non-hazardous, depending on whether it contains solvents, THC, or other contaminants.
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How do cannabis cultivators dispose of plant waste?
Cannabis cultivators must follow state-specific regulations for waste disposal. Non-hazardous waste, such as leaves, stalks, and root balls, can be composted, incinerated, or sent to a solid waste facility. Hazardous waste, like solvent-contaminated materials, must be handled by licensed disposal companies.
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Are there sustainable ways to manage cannabis waste?
Yes, sustainable cannabis waste management methods include composting plant material, using waste for hemp-based products like hempcrete, and repurposing leaves as animal feed. Some industrial composters, like the Brome Industrial Rotating Composter, can efficiently process cannabis waste into nutrient-rich soil amendments.
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Why do some states require cannabis waste to be rendered unusable?
States like Maine mandate that cannabis waste be rendered unusable to prevent unauthorized use or resale. This process often involves grinding plant material and mixing it with non-cannabis waste, such as food scraps or manure, in a 50:50 ratio before disposal.
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What are the legal risks of improper cannabis waste disposal?
Improper cannabis waste disposal can result in hefty fines, regulatory penalties, or even loss of a business license. Common violations include failing to label waste correctly, not using approved disposal methods, or improperly handling hazardous waste containing THC or solvents.
