Regulation of Wastewater Associated with Marijuana Growing and Processing Operations
The Oregon Department of Environmental Quality does not directly regulate the growing or processing of marijuana. However, marijuana businesses must abide by existing regulations designed to protect our air, land and water. DEQ has a limited role in wastewater management associated with growing and processing operations, and the regulations differ depending on whether wastewater is associated with an agricultural operation or disposed via sanitary sewer or onsite septic system.
Additional information on Oregon laws and regulations relating to marijuana are available at the Oregon Liquor Control Commission.
Wastewater from marijuana growing operations and marijuana processing operations are regulated differently.
Marijuana growing operations on agricultural lands are considered farm uses and therefore agricultural wastewater management falls under the authority of the Oregon Department of Agriculture (ORS 568.900 – 568.933). This applies to greenhouses and hydroponic operations as well as open air grow sites.
- House Bill 3400, passed by the Oregon Legislature in 2015, establishes that marijuana is a crop for the purposes of determining a “farm use” as defined in ORS 215.203.
- ORS 561.191 establishes that the Oregon Department of Agriculture is the lead agency for programs and rules that directly regulate farming practices related to water quality protection.
- See ODA’s website for more information on authorities and programs for regulating agricultural activities affecting water quality.
DEQ only has a regulatory role in managing wastewater from growing operations if it is being discharged into a sanitary sewer system, an onsite septic system, or being discharged directly into a surface water body through a pipe or ditch.
Municipal wastewater discharges
Growers and processors should contact the local sanitary authority for information about connecting or discharging wastewater to a sanitary sewer system. Under certain circumstances, DEQ pretreatment regulations may apply.
Onsite septic systems discharges
Wastewater from growing facilities and processing facilities may not be discharged into an onsite septic system designed to treat domestic (household) wastewater. In addition, planting and growing marijuana on top of a septic drainfield or irrigating and harvesting over a drainfield may impair a residential septic system’s performance. For more information contact the onsite septic system authority in your county
Surface water discharges
Wastewater from growing and processing facilities that discharge directly to a surface water through a ditch, channel, or pipe requires a National Pollutant Discharge Elimination System (NPDES) permit. Contact DEQ for more information.
Wastewater from growing facilities and processing facilities may not be discharged underground. Underground Injection of wastewater may cause groundwater contamination which is costly, difficult, and sometimes impossible to clean up. For more information contact DEQ’s Underground Injection Control
Marijuana processing wastewater, including but not limited to wash water, process wastewater from extraction processes, and wastewater from food preparation may be subject to DEQ regulation. Contact DEQ for more information.