By Jacob Strauss, PE, EWMA
Water is essential to any agricultural operation, and the cannabis industry is no exception.
Cultivation facilities where cannabis is grown often require immense amounts of water to grow plants, while manufacturing operations that make products like edibles may produce a consistent flow of wastewater. To succeed in cannabis, you don’t just need knowledge of the plant and a sound business plan; you also need the right permits and compliance plans. It’s essential to secure wastewater and stormwater permits, and create a management plan that ensures you’re using this valuable resource in the most efficient way possible.
Cultivation facilities use water for plant fertigation, cooling HVAC systems essential for climate control, fire suppression and sprinkler systems, and sanitary waste. Statistics from 2021 say that, on average, one cannabis plant needs six gallons of water per day, nearly double the roughly 3.3 gallons required for wine grapes. All that water use — plus where that water goes and what it contains — is a priority for local authorities, who require the proper water and sewer permits to let operations get off the ground.
Large cultivation facilities and hydroponics operations in New Jersey, for example, may require a Treatment Works Approval (TWA) permit in addition to the standard wastewater permits. This permit is issued by the New Jersey Department of Environmental Protection (NJDEP) and applies to facilities that expect to discharge 8,000 gallons of water per day or more.
Cannabis product manufacturers may also generate significant amounts of wastewater and require the same permits as cultivators. But stormwater management is just as important for this sector. Manufacturers may need a permit for industrial stormwater discharge that requires best management practices to limit water exposure to chemicals used in the manufacturing process.
Possible contaminants include industrial solvents like hydrocarbons or ethanol used to create some cannabis extracts. The conditions of a wastewater permit also often require frequent testing – usually with the help of environmental consultants – to demonstrate that wastewater discharge is not contaminated.
While cannabis operators need the necessary permits regardless of operation type, there are water management techniques that not only make permit approvals easier and reduce negative effects on the environment, but help to save money on this significant expense. These include using a closed loop system to recycle water, employing drip irrigation systems to limit water consumption, and installing monitors and sensors to help manage water usage. A licensed engineer can steer you in the right direction when designing and installing these systems.
Cannabis operators can’t afford to overlook water management as part of their plans to enter this exciting new industry. Licensed engineers at environmental consulting firms can set up these plans properly from the get-go, satisfying regulatory needs while influencing the bottom line through cost savings and potential tax benefits. Don’t go it alone when it comes to water usage and management — contact a professional to be sure you’re checking all the boxes.
Jacob Strauss is senior project engineer for EWMA.
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