When it comes to being environmentally friendly, there are things  marijuana businesses can do voluntarily and things that states mandate  they do.
Like any type of business, marijuana companies are required to comply  with environmental and energy regulations laid out by their respective  states.
Such regulations can include how to treat or dispose of wastewater  and adhere to energy-efficiency standards that often require specific  lighting or heating, ventilation and air conditioning (HVAC) equipment.
The cannabis industry’s outsized impact on the environment –  especially high energy and water use – increasingly is catching the  attention of regulators, and some states are developing  marijuana-specific environmental regulations in response.
“Energy efficiency was a bit of an afterthought as states were  putting their rules together,” said Sam Milton, principal of Portland,  Maine-based Climate Resources Group, a consultancy specializing in  indoor horticulture.
“It’s just not, frankly, a huge priority of regulators or the  commissions,” he said. “The environmental stuff gets shunted aside.”
States that have taken cannabis-specific environmental action include  California, Illinois, Massachusetts, Michigan and New York.
Some cities and towns also have taken environmental measures, such as  Ann Arbor and Grand Rapids in Michigan, Beverly, Massachusetts, and  Boulder, Colorado.
While these areas have their own rules, there are some common themes  among the regulations, most notably an effort to reduce the cannabis  industry’s voracious energy usage, Milton said.
“The first theme is: How do we limit the overall energy intensity of  the industry, the lighting and the HVAC? Those are the two biggest areas  that comprise cultivators’ energy use,” he said.
“States with mandates, they address those two technology types.”
For example:
California
The state requires that growers use an integrated HVAC system with  on-site heat recovery for reheating dehumidified air as well as a  chilled water system with on-site heat recovery for reheating  dehumidified air.
Massachusetts
Growers’ lighting power density (LPD) may not be higher than 36 watts  per square foot of canopy – essentially, a 576-watt bulb for a 4- x  4-foot grid.
Licensees also can comply by using lighting fixtures from the  DesignLights Consortium’s Horticultural Qualified Products List that  have photosynthetic photon efficacy (PPE) that is 15% above the  organization’s minimum.
The state also requires license applicants and renewals to submit an annual report showing energy, water and gas use.
Illinois
The state has similar rules to Massachusetts, except they apply only to recreational cultivators.
Illinois cultivators, depending on their size, must use ductless,  split HVAC units, variable refrigerant flow HVAC units or similar  energy-efficient HVAC options.
Illinois also mandates automated watering systems and equipment for capturing condensate.
New Jersey and Oregon
Cultivation license applicants must submit energy- and water-use plans as well as waste-management plans.
New York and Vermont
All require license applicants and renewals to submit an annual report showing their energy, water and gas use.
While Milton and other industry sustainability advocates welcome a  bigger focus by states to make for a greener cannabis industry, they  said the measures often have only marginal impact.
One problem is that these regulations are hard to enforce, Milton said.
An exception is Massachusetts, which requires an independent,  third-party energy evaluator to certify that licensees are complying  with environmental rules.
Evaluators check what type of lights are being used, how many there are and the lighting layout, Milton said.
He also believes that state regulators tasked with crafting and  enforcing environmental rules should be better educated on  cannabis-sustainability issues.
“The regulators need to get educated around what the regulations actually entail,” Milton said.
“They have a checklist of stuff they need to be looking for in the  facility; all the aspects – especially the energy piece – can be very  technical.
“The inspectors are often not qualified to be inspecting for energy and environmental rules and regulations.”
Beyond that, regulators need to educate growers about the rebates  that are available to them when they buy energy efficient equipment.
Incentives and information about that is more effective than regulations that deter somebody, Milton said.