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Guide to Environmental Requirements for the Cannabis Industry

Guide
Photo shows cannabis plants growing for transplant.
This is an overview of environmental requirements for cannabis industries as currently understood by the City of Portland. The City may impose additional requirements for businesses as more information regarding the pollutants of concern outlined below or others becomes available.
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The City’s Role

The federal Clean Water Act requires cities to regulate industries that discharge wastewater or stormwater to the city’s sewer systems. As the City’s sewer and stormwater services provider, Environmental Services sets the pollutant limits and regulates industries in order to protect the City’s system and our watersheds.

City environmental regulations can impact various phases of the cannabis industry from cultivation to product production. Below, we've identified pollutants of concern for each phase, how businesses can mitigate for them, and Environmental Services' requirements for those pollutants. This is preliminary guidance regarding regulatory requirements for business owners and individuals interested in the cannabis industry. Environmental Services may update this information as more information becomes available in order to prevent pollution and protect the sewer and stormwater systems.

Cultivation and Plant Growing Operations

Businesses growing cannabis plants for processing into consumer products.

Pollutants of Concern: Nitrates, phosphorus, pesticides, and fungicides

Mitigation Strategies:

  • Control chemical use and optimize nutrients and biocides application or dosing to minimize chemical waste.
  • Eliminate sewer entry points. Do not install drains or sumps in cultivation rooms. (This may not be possible for hydroponic facilities due to high water usage.)
  • Store all chemicals in areas without access to sanitary or storm sewer systems or in secondary containment.

Environmental Services Requirements

Cannabinoid Extraction

Businesses involved in the extraction of active ingredients from plant material.

Pollutants of Concern: Various solvents used to extract oils from cannabis plants:

  • Gaseous solvents like carbon dioxide, propane, or butane cannot be introduced into wastewater, so they are not regulated by Environmental Services.
  • Liquid solvents like hexane and alcohols are regulated.
    • Hexane partitions in wastewater are highly flammable and present a hazard.
    • Alcohols, while flammable, dissolve in water and are biodegradable at the wastewater treatment facility. In small quantities, alcohols do not present a hazard.

Mitigation Strategies:

  • Employ closed loop systems. These extraction systems minimize the amount of product and chemicals that can be discharged in wastewater.
  • Store all chemicals in areas without access to sanitary or storm sewer systems or in secondary containment per Portland City Code 17.34.

Environmental Services Requirements

Food Production with Cannabinoid Oils

Businesses involved in the extraction of active ingredients from plant material.

Pollutants of Concern:

  • Fats, oils, and grease can block sewers and cause sewage backups and overflows.
  • More concentrated wastewater pollutants including Biochemical Oxygen Demand and Total Suspended Solids. “Extra Strength” wastewater costs more for Environmental Services to treat. Businesses often pay increased wastewater rates, as a result.

Mitigation Strategy: Install and maintain a grease removal devices per Oregon Plumbing Specialty Code and City rules.

Environmental Services Requirements

Grease Removal Device: Installation and maintenance requirements are outlined in ENB-4.26, Fats, Oils, and Grease Removal Program Administrative Rules or the Grease Interceptors page.

Extra Strength Sewer Charges: Most cannabis edible food manufacturers produce confectionery goods and are billed at the same rate as confectioners per ENB-4.25, Extra Strength Charge Program Administrative Rules.

Monitoring Access Structure: Establishments with discharge volumes greater than 6,000 gallons per day may need to install a monitoring access structure per ENB-4.35, Administrative Rules for Monitoring Access Structures.

Cannabis Dispensaries

Currently, there are no known pollutants of concern specific to this aspect of the industry.

Additional Resources