I recently blogged about the various kinds of environmental regulatory issues I anticipate will emerge in New York and New Jersey as each state’s cannabis industry blooms. In that post, which you can find here, I identified cannabis waste disposal as a complex environmental issue that each state will be expected to address as the industries develop. Cannabis cultivators generate significant amounts of organic and inorganic waste, which includes plant waste, growing media, and other agricultural material (not to mention hazardous wastes in the form of volatile organic compounds). In this post, I will dive a little deeper into the issue of cannabis plant waste disposal and discuss some of the possibilities.

50/50 Plant Waste Rule

The states leading the charge on recreational cannabis cultivation have generally addressed the issue of plant waste disposal and have by and large coalesced around the so-called 50/50 rule, whereby marijuana plant waste must be made unusable and unrecognizable, and then disposed of as solid waste. However, each cannabis waste generator must take the resulting mash and mix it with other solid waste such that each generator’s solid waste consists of no more than fifty percent cannabis waste. On its face, such a rule seems sensible, but critics point out that the 50/50 rule is flawed in that it forces organic wastes – which could otherwise be put to beneficial reuse – to be landfilled, which itself creates negative environmental impacts. Critics have also suggested that the 50/50 rule is transportation-centric, relying heavily on carbon-emitting waste disposal infrastructure and that the rule encourages cannabis businesses to produce unnecessary levels of non-cannabis solid waste in order to meet the fifty-percent threshold.

Composting and Anaerobic Digestion

Although less common than the 50/50 rule, states have been coming around to the idea of allowing businesses to dispose of marijuana plant waste outside of the solid waste stream. Massachusetts, for example, allows cannabis businesses to dispose of marijuana plant waste by mixing it with other organic matter, such as food waste, soil, mulch, manure, and growing media, and to then dispose of that waste at offsite composting or anaerobic digesting facilities. Alternatively, Massachusetts-based cannabis businesses are permitted to compost marijuana plant material on-site, though permissive on-site composting appears to be much more limited. Advocates for such methods point out that composting or anaerobic digestion of cannabis plant matter would result in effectively a complete diversion from landfilling the waste and ensure that the plant matter can be put to beneficial reuse.

Notably, these alternative means of disposal present workable options for New York and New Jersey. Both states have recently passed food waste recycling acts that will require certain businesses to dispose of food waste through authorized recycling facilities, which in both states, include off-site composting and/or anaerobic digestion. Permitting cannabis-waste generators to dispose of their plant waste in the same manner as food waste – and perhaps mixed with food waste, if necessary – would seemingly promote each state’s environmental policy goals underlying their respective food waste acts and provide cannabis-waste generators with an environmentally sound means to dispose of their plant matter.

New York and New Jersey are likely a long way away from fully hashing out how to handle marijuana plant waste, but as new developments arise, we will keep an eye out.