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Hemp and CBD Oil Extraction

Hemp field
Picture by Ronne Adkins. Location Agricenter International in Memphis

Hemp growing

Hemp or cannabis cultivation is a growing industry in Tennessee. The signing of the 2018 Federal Farm Bill removed hemp from the Controlled Substances Act and deemed it an agricultural commodity. This includes hemp products such as CBD which stands for cannabidiol, an oil extracted from the flowers of the hemp plant. It should be noted that hemp is a term used to define cannabis plants that contain 0.3% or less of THC (delta-9-tetrahydrocannabinol). Marijuana is the term used to define cannabis plants that contain more than 0.3% of THC which is the active substance in marijuana and why it is subject to the Controlled Substances Act. Both are cannabis plants, similar to how roses can be red, yellow, or several other colors, but still be a rose. As such, it is difficult to tell by sight or smell whether a cannabis plant would be defined as hemp or marijuana. Hemp is legal to grow in accordance with TN Department of Agriculture rules and regulations. Marijuana is not legal in Tennessee. Because of these definitions, the term hemp will be used rather than the more generic, but scientifically accurate, cannabis.

The growing of hemp is regulated by the TN Department of Agriculture. The Department of Agriculture has several pages of information available on their website, including the steps to get started, forms and publications, and rules and regulations surrounding this industry. Part of the rules and regulations relates to required testing of hemp crops to determine the amount of THC the plants contain. If the plant is found to contain more than 0.3% THC, the Department of Agriculture will issue a departmental directive or destruction order. 

The Small Business Environmental Assistance Program (SBEAP) is available to provide some assistance to hemp growers in relation to environmental issues. As this is primarily an agricultural segment of the industry, the Department of Agriculture and related programs may be able to provide more direct and knowledgeable assistance. See the Agribusiness resources section of the SBEAP Agribusiness website for some of these programs.

CBD oil extraction

The SBEAP is able to provide more assistance to CBD oil extractors as they are considered an industry and as such would be more subject to environmental regulations for air, water, and waste. If products are made for consumption (sometimes termed ingestibles), the CBD oil extractor would need to be permitted as a food production facility through the Department of Agriculture. The TN SBEAP has developed a guidance for CBD oil extractors that covers several environmental issues that can occur with the CBD oil industry. The Colorado SBEAP contributed to a best management practices guide that is focused mostly on growers (including marijuana growing), but does include information for CBD oil extractors. 

Air emissions from CBD oil extractors can come from several sources. Most unique to this industry would be the extraction process itself. Ethanol is a common extraction solvent, but when it evaporates, it would result in a Volatile Organic Compound (VOC) emissions. Even if ethanol is not used as the primary solvent, it may be used for additional extraction during the process. Other solvents, some of which may result in Hazardous Air Pollutants (HAPs), may also be used and would need to be calculated to determine air emissions from the facility. The guidance explains how to calculate emissions based on emission factors or mass balance. Another method would be test results from the manufacturer of extraction equipment. In addition to the extraction process, air emissions can come from boilers, emergency engines, or other processes that may emit air emissions. Depending on the amount of potential emissions from a facility, an Air Pollution Control Construction Permit may be needed. 

Waste issues are mostly related to the spent plant material following extraction. If ethanol or other solvents aren't sufficiently removed from the plant material, the plant material could be considered a hazardous waste. Disposal of such would require notification as a generator of hazardous waste and must comply with storage, recordkeeping, and handling requirements. Waste that is not considered hazardous may be classified as a special waste, which allows for multiple reuse options including land-use application. 

Water issues would tend to fall into three main categories: Construction, operation, and local publically owned treatment works (POTW). A construction storm water permit would be needed if an acre or more of land is disturbed. An operating permit would generally apply to industrial storm water unless a Notification of No Exposure is submitted. The local POTW would have authority over what discharges are sent to the local wastewater treatment facility as each POTW has different capacities and capabilities. If a CBD oil extractor is not located in an area where their wastewater would go to a POTW, they may need to discuss with the TDEC Environmental Field Offices concerning the ability of a septic system to handle the waste water.

Refer to the Guidance on Cannabidiol (CBD) Oil Extraction Environmental Permitting in TN for more details on environmental issues related to CBD oil extraction. The TN SBEAP is also available for assisting small businesses with these issues and permitting questions.