Marijuana Licensing and the Environment

With the passage of I-502, businesses and communities are seeking information about what impacts recreational marijuana (cannabis) growers and processors may have on the environment and what environmental permits might be required in the state of Washington.


General licensing questions are addressed by the state Liquor and Cannabis Board.

Permits are site specific

As with all proposed projects, I-502 licensees should start by considering local regulations and ask what approvals may be needed through their county or city permitting offices.  Permits and permissions for a project depend on zoning rules, location and operation information.

A pre-approval meeting will help determine whether to complete an environmental checklist (SEPA). This checklist provides an initial snapshot of a project’s environmental impacts. Decision-makers must consider likely environmental consequences.

As projects move forward, proponents may want to coordinate with Ecology, Liquor and Cannabis Board (LCB) and the Governor’s Office for Regulatory Innovation and Assistance (ORIA).

Possible permits and environmental considerations

This is not a comprehensive list, but designed to prompt consideration as projects evolve.

Air Quality

  • A greenhouse growing or processing operation may need an air quality permit for the heating system.  The need would be based on the size of the heating unit and amount of fuel used if the system is not electrical.
  • Odors may need to be controlled.

Water Quality

  • Growers and processors may be able to discharge wastewater to local sewage treatment plants.  Growers and product processors can contact their regional Ecology offices or local jurisdictions to be sure they can discharge to local sewers.
  • If they cannot, they can seek information from Ecology to determine if they need a water quality permit to protect surface and groundwater.
    • Wastewater Discharge Checklist: This checklist describes discharge options for marijuana producers and processors and requests information for Ecology to evaluate the need for a water quality permit.

Water Resources

  • Marijuana growers may or may not need a water right permit to water plants.
  • Water availability can vary significantly from county to county or water source to water source.
  • Industrial greenhouses and outdoor growers may be able to hook up to an existing water purveyor, such as a city utility or irrigation district.
  • Growing operations and greenhouses are limited in size by the Liquor and Cannabis Board and as a small use may qualify under a permit exemption for a groundwater well.
  • There may be local rules or requirements related to a new permit exempt well or new surface water uses, depending on the watershed.
  • The U.S. Bureau of Reclamation issued a policy statement prohibiting the use of federal water or facilities for the cultivation of marijuana.  Questions on the policy should be directed to the bureau.

Waste Management

  • Solid waste management is regulated at the local level by county health departments. Businesses should consult with their local health department to determine the amount of solid waste oversight needed.
  • Marijuana licensing rules require that marijuana stems and organic waste from growing and processing operations be rendered unusable by mixing them with at least 50 percent other specific materials and grinding them up before disposal or composting (WAC 314-55-097 (5)(a and b). Unprocessed marijuana plants, trim, roots, and bud are not considered dangerous waste under WAC 173-303.
  • Growers and processors should employ common recycling and e-cycling practices.
  • Growers should consider pesticide management and consult with the Washington Department of Agriculture on pesticide and fertilizer use.
  • If any dangerous wastes are generated, dangerous waste regulations need to be followed. Some dangerous wastes to consider:
    • Any processed, concentrated marijuana waste with 10 percent THC (tetrahydrocannabinol) or greater would designate as a state-only dangerous waste (WT02)
    • Fluorescent bulbs or other bulbs with mercury
    • Unused pesticides/herbicides/etc. that are to be disposed
    • Waste solvents
    • Used batteries
  • Waste generated from processing cannabis must be designated to determine if it is dangerous waste. Process wastes contaminated with the solvents allowed by the Liquor and Cannabis Board (LCB) for extraction would not designate as dangerous waste under normal conditions because:
    • They are not a liquid with a flash point less than 140 degrees F (WAC 173-303-090(5)(i)), and
    • They are not a solid which may ignite through friction, absorption of moisture, or spontaneous chemical change, and
    • They are not listed dangerous waste, listed solvents (WAC 173-303-9904; waste codes F001 – F005).
  • See the Regulatory Guidance for Cannabis Operations for more information about cannabis disposal.

Related Links:

Office for Regulatory Innovation and Assistance (ORIA)

ORIA Information Center, 360-725-0628 - for general permitting assistance

Liquor and Cannabis Board guidance

Informative factsheets with permitting guidance for growers and producers

Department of Health information

Medical Marijuana