With 10 states and the District of Columbia having legalized recreational cannabis (representing nearly a quarter of the U.S. population, including the most populous state), an emerging issue is how to deal with the odor generated by marijuana production facilities. A December 19, 2018 article in The New York Times noted a growing number of neighbors of cannabis farms are complaining about “skunky” odors caused by certain volatile organic compounds generated during growing and processing. The Times cited Sonoma County in California, which it reported received more than 730 complaints about cannabis last year, nearly two-thirds related to odor. Regulators at the state, regional and local levels are attempting to deal with these issues through a combination of permitting, land use and nuisance rules.

In states such as Washington and Colorado, where recreational cannabis has been legal since voter initiatives passed in 2012, regulators have addressed odor as an air quality issue. For example, in the Puget Sound region, the Puget Sound Clean Air Agency — typically recognized in the industry as “PSCA,” or the organization you may have received an unexpected and nondescript invoice from — does not have a specific regulation for marijuana odors. It does, however, have jurisdiction to impose limitations on marijuana production facilities under the state’s general regulations for air pollution sources (WAC 173-400). PSCA regulates odors through the Notice of Construction process, which operates in conjunction with local permitting processes, such as a conditional use permit, and licensing by the Washington State Liquor and Cannabis Control Board.

The PSCA odor regulations set a “best available control technology” (BACT) standard, which is the maximum degree of reduction for each air pollutant subject to regulation under the Washington Clean Air Act (RCW 70.94) that the permitting authority determines is achievable, taking into account energy, environmental, economic and other costs. PSCA’s rules are based on a nuisance standard — causing or allowing an air contaminant in sufficient quantities and of such characteristics and duration as is, or is likely to be, injurious to human health, plant or animal life, or property, or which unreasonably interferes with enjoyment of life and property.

For marijuana producers under PSCA’s jurisdiction (King, Snohomish, Pierce and Kitsap Counties), the agency has determined that BACT means no detectible cannabis odor outside the facility property line. The agency in recent permitting actions has implemented this standard by requiring operators to design all exhaust points (e.g., vents, stacks, windows, doors) associated with an enclosure, building or greenhouse for cannabis production or processing to continuously control odors and volatile organic compounds (VOCs) using carbon adsorption technology, which involves placement of carbon canisters before emission points. At a minimum, these carbon units must be replaced every quarter. An operator also must have a person who has not been exposed to the smell periodically monitor the air at the property line to determine compliance with the “no detectible odor at or beyond the property line” standard.

One significant ramification of this standard is that PSCA does not believe outdoor cannabis production facilities can continuously achieve the “no odor outside the property boundary” standard without the proper use of an enclosure that routes emissions to a carbon adsorption system. PSCA also does not allow odor masking, such as spraying a curtain of scented oil vapor around the perimeter of greenhouses. Although the Times article mentions this system as a way one California grow operation has tried to mitigate odors, PSCA will not accept that as a control technology.

In Colorado, cannabis cultivation facilities are designated as agricultural activity and exempt from state air quality regulations unless they are a major source of pollution. The City and County of Denver, however, has an odor ordinance that requires cultivation facilities control the odor impacts of their operations. An August 2018 draft of the Denver Department of Public Health & Environment’s “Cannabis Environmental Best Management Practices” (BMP) recommends use of carbon filtration to reduce the VOC emissions from a cannabis cultivator. In addition, draft guidance recommends other best management practices, including:

  • Regular inspection and maintenance of HVAC systems;
  • Sealing the grow space within a greenhouse and circulating air for approximately one week and purging exhausts during low ozone formation periods (evenings, windy days, cloudy days);
  • Ensuring temperature and relative humidity are under control and within tolerances so that high temperatures and humidity do not perpetuate odor issues;
  • Having a system in place to record and respond to odor complaints;
  • Purchasing a “scentometer” or Nasal Ranger to quantify odors and record data from self-testing;
  • Timing harvests to minimize ozone impact and minimizing emissions during morning, early afternoon and summer; and
  • Train and allocate responsibilities among staff members to ensure consistent and continuous implementation of BMPs.

Colorado facilities manufacturing marijuana-infused product are subject to health and safety regulations and regulations on extraction processes in the Colorado Code of Regulations. Those facilities must estimate their VOC emissions from solvent uses and follow the state’s Air Pollutant Emission Notice and permitting requirements.

With the increasing production of cannabis for recreational purposes, more conflicts with neighbors are likely. This is a situation where an ounce of prevention by implementing a wide-range of BMPs could go a long way toward reducing the risks of litigation and enforcement.

The White House Office of National Drug Control Policy (ONDCP) recently released “An Initial Assessment of Cannabis Production, Distribution, and Consumption in Oregon 2018 – An Insight Report.” The report “does not purport to be a policy evaluation or policy performance review; rather [the] assessment provides a verifiable analysis of assorted information and data.” A review of the data and its presentation raises more questions than it answers. The assessment presents data in a way that conflates Oregon’s adult-use, medical and black markets. As a result, it is challenging to determine what, if any, policy response might be appropriate.

The U.S. Attorney for the District of Oregon provided a statement in response to the assessment. The statement describes the production, distribution and consumption in Oregon as “out of control” and suggests, “state officials should respond quickly and in a comprehensive manner to address the many concerns raised.” The U.S. Attorney requests, “continues to be for transparency, responsible regulation, adequate funding, and a willingness to work together.” He further adds, “[i]t’s time for the state to wake up, slow down, and address these issues in a responsible and thoughtful manner.”

Fair enough. So let’s take a look the assessment and see how meaningful the current data really is. The assessment’s key findings include:

  • The Oregon Burn Center spent $9.6 million for initial acute care treating impatient burn victims from July 2015 through January 2018 that related to cannabis extract production.
  • During the same period, law enforcement investigated 64 cannabis processors, 21 of which resulted in fire or explosion.
  • A mature cannabis plant consumes 22.7 liters (6 gallons) per day.
  • A single kilogram (2.2 pounds) of finished flower requires 5.2 megawatt hours of electricity — this is equivalent to running a 1,000 watt grow light 24 hours a day for 225 straight days!
  • Cryptocurrencies such as bitcoin and ether are used for cannabis transactions.
  • A glut of cannabis stockpiles stemming from overproduction caused a 50 percent annual price drop since 2016.
  • As of 2018, only 31 percent of available cannabis inventory was distributed, leaving 69 percent unconsumed within the adult-use program.
  • Illicit cannabis cultivation on public lands persists unabated, despite the state-sanctioned adult-use market.
  • Illicit out-of-state distribution persists after the emergence of the state-sanctioned adult-use market.
  • Oregon’s annual production capacity far exceeds its estimated annual consumption demands — there is one grow site for every 19 users (probably includes both medical and recreational grows, but not adult-use home grows).

There is an obvious elephant in the room.  The production and sale of cannabis remain illegal under the Controlled Substances Act, and the Attorney General has made his views on the state legalization of marijuana quite clear. So there might well be an inherent bias as a result (similar to EPA’s recent conclusion that larger cars will reduce fatalities and fuel consumption because people will drive less because fuel will be more expensive and they can carry more groceries in their cars). That said there is the obvious problem of cannabis demand throughout the U.S., including in states without medical or adult-use programs. Prior to its medical and adult-use programs, people were illegally producing and exporting cannabis from Oregon. Few would question the conclusion that Oregon has, and will continue to have, an export problem when there is money to be made from illegally producing and selling cannabis.

Still, at least two of the data points stand out as possibly incorrect or at least misleading given the report’s statement that they constitute “verifiable analysis of assorted information and data.” The first is the statement that a single mature plant consumes, on average, 6 gallons of water per day. The second is that it takes approximately 5.2 megawatts of electricity to produce a single kilogram of (indoor) finished flower.

Digging deeper into the assessment, it notes, “definitive information varies about the water needs of cannabis cultivation with estimates ranging widely from 1 to 15 gallons daily.” The six gallons per day figure comes from a California study. That study relied on “high-resolution aerial imagery to estimate the number of marijuana plants being cultivated in four watersheds in northwestern California” and “estimated the water demand of marijuana irrigation.” However, the water estimates “were based on calculations from the 2010 Humboldt County Outdoor Medical Cannabis Ordinance draft.” I was unable to locate a specific water estimate in that ordinance. It simply states, “the cultivation of marijuana in areas not served by public water systems may result in large, unregulated withdrawals of water from creeks, streams, and rivers.” It remains unclear where the 6 gallons per day figure actually comes from, how accurate it actually is, and whether it equally applies to indoor and outdoor operations, which are in compliance with state law.

The claim that it takes approximately 5.2 megawatts of electricity to produce a single kilogram of finished flower comes from a 2017 paper titled “High Time to Assess the Environmental Impacts of Cannabis Cultivation.” The paper does not analyze electricity use, but rather states “it has been estimated that the power density of marijuana cultivation facilities is equal to that of data centers and that illicit grow operations account for 1% of the U.S.’s average energy use.” The paper cites a 2012 paper titled “The carbon footprint of indoor Cannabis production.” A subsequent paper titled “Trends and Observations of Energy Use in the Cannabis Industry,” citing the 2012 study, notes the author “calculates that it takes approximately 13,000 kWh per year to operate a standard production module that is 4’x4’x8’. This is based on a production cycle of 78 days, for 4.7 cycles per year, and simple assumptions about the equipment capacities and use.” There is an obvious leap between a small 4’x4’ grow space and larger indoor production facilities that employ LED lighting. Indeed, the author of the subsequent paper suggests that, “falling product prices will drive the need for more competitive operating costs, which will largely be presented in the form of energy efficiency.” There are arguably energy savings from larger indoor grows, outdoor production and the use of indoor greenhouses that rely on light deprivation techniques.

My view is that the U.S. lost the federal war on all drugs long ago, not just cannabis. Nevertheless, the law is the law and, regardless of Oregon legalization, we cannot permit growers to operate on federal lands. OLCC licensed businesses must support efforts to eliminate market participants that do not follow the rules, and they must take better care to ensure that their product does not enter the black market. Lastly, OLCC enforcement also needs to be stepped up — following adequate funding from the State Legislature — if for no other reason than to prevent further wrath of the federal government.

Most of our readers probably concur that the U.S. Attorney’s call to Oregon to “wake up” is misplaced. Our federal anti-drug resources would be far better directed at the community-destroying opioid crisis, but that seems unlikely to happen under the current Attorney General unless and until Congress gets its act together to pass the STATES Act. Evidence already exists that medical marijuana (1) reduces the daily doses filled for opioids, (2) reduces opioid overdose deaths, and (3) facilitates the substitution of marijuana for opioids. Removing cannabis from the Controlled Substances Act in states where the people and the local government have decided that there are larger public health issues to worry about would allow our federal government to not only respect public sentiment regarding cannabis but also liberate funds do help those affected by life-destroying pharmaceuticals.