Best Management Practices Cannabis Cultivation

The following Best Management Practices (BMPs) are designed for in-ground cultivation, but shall be applied to container grown cannabis as applicable. The BMPs for water quality shall apply to all cultivators not required to enroll in the North Coast Regional Water Quality Control Board Waste Discharge program for cannabis.

Outdoor Cultivation

Pesticide and Fertilizer Storage
1. Pesticide and fertilizer storage facilities shall be located outside of the Riparian Corridor setbacks for structures as listed in this document(PDF: 6.74 MB)
2. Pesticide and fertilizer storage facilities shall not be located within 100 feet of a wellhead, or within 50 feet of identified wetlands.
3. Pesticide and fertilizer storage facilities shall be adequate to protect pesticide and fertilizer containers from the weather.
4. Store all bags and boxes of pesticides and fertilizers off the ground on pallets or shelves.
5. If the structure does not have an impermeable floor, store all liquid pesticides and fertilizers on shelves capable of containing spills or provide appropriate secondary containment.
6. Routinely check for leaks and spills.
7. Have spill cleanup kit onsite to be able to respond to any leaks or spills.
Pesticide Use
1. Inspect planting stock for pests and diseases prior to planting. Avoid planting stock with pests and disease.
2. Comply with all pesticide laws and regulations as enforced by the California Department of Pesticide Regulation.
3. For pesticides with the signal word CAUTION that have listed food uses, comply with all pesticide label directions as they pertain to personal protective equipment, application method, and rate, environmental hazards, longest reentry intervals and greenhouse and indoor use directions.
4. For all other pesticides, use must comply with all label requirements including site and crop restrictions.
5. Prior to the use of any registered pesticide on cannabis, obtain an Operator Identification Number from the County Agricultural Commissioner.
6. Submit monthly pesticide use reports to the County Agricultural Commissioner.
Fertilizer Use
1. Prior to applying fertilizers, evaluate irrigation water, soils, growth media, and plant tissue to optimize plant growth and avoid over fertilization.
2. Apply fertilizers at label rates.
3. Do not apply fertilizers in a way that will result in runoff that may contaminate ground or surface water.
Riparian Protection
1. Observe riparian corridor setbacks for agricultural cultivation as applicable. These shall be maintained as “no touch” areas. The removal of vegetation is prohibited within the setback.
2. No equipment, vehicles, or other materials shall be stored in the riparian setback.
3. Composting areas shall not be located in the riparian setback area.
4. For more information on best management practices for agricultural cultivation within the Riparian Corridor, please go to sonomacounty.ca.gov/Agriculture-Weights-and-Measures/Agriculture-Division/Ordinances/Best-Management-Practices-for-Agricultural-Cultivation/
Water Use and Storage
1. Irrigation must be conducted in a manner that does not result in runoff from the cultivated area.
2. Any water tanks or storage facilities must obtain all necessary permits from the Sonoma County Permit and Resource Management Department (PRMD).
3. The use of water bladders is prohibited.
4. If using an irrigation system, inspect for and repair leaks prior to planting each year and continuously during the season.
5. Irrigation systems shall be equipped with a backflow prevention devices and shutoff valves.
6. 6. Waste Management
7. Recycle or properly dispose of all plastic bags, containers, and irrigation materials.
8. Properly dispose of green waste in a manner that does not discharge pollutants to a watercourse. This may be accomplished by composting, chipping, and/or shredding. The method of green waste disposal must be documented.
9. Used growth medium (soil and other organic medium) shall be handled to minimize or prevent discharge of soil and residual nutrients and chemicals to watercourses. Proper disposal could include incorporating into garden beds, spreading on a stable surface and re-vegetating, storage in watertight dumpsters, or covering with tarps or plastic sheeting prior to proper disposal. The method of disposal must be documented.
10. Compost piles are to be located outside of riparian setbacks for agricultural cultivation and in a manner that will not discharge pollutants to a watercourse. If necessary, construct a berm or install fiber roll around compost area to prevent runoff or use straw wattles around perimeter.
11. Cover compost piles with tarp or impermeable surface prior to fall rains and continuously throughout the rainy season.
Erosion Control/Grading and Drainage
1. Leave a vegetative barrier along the property boundary and interior watercourses to act as a pollutant filter.
2. Avoid soil disturbance between November 1 and April 15.
3. All exposed and disturbed soil must be covered with a minimum of 2 inches of mulch, such as straw, bark, wood chips, etc., by November 15. Alternatively, establish a thick cover crop over disturbed areas.
4. Erosion control materials shall be available on site at all times in the form of straw or appropriate mulch adequate to cover area of disturbed soil. In the event of a forecast storm event likely to produce runoff, apply mulch to disturbed areas prior to rain event.
5. Any grading or drainage conducted as part of site preparation shall have the appropriate permits from the Sonoma County PRMD.

Indoor Cultivation

Pesticide Use
1. Inspect planting stock for pests and diseases prior to planting. Avoid planting stock with pests and disease.
2. Comply with all pesticide laws and regulations as enforced by the California Department of Pesticide Regulation.
3. For pesticides with the signal word CAUTION that have listed food uses, comply with all pesticide label directions as they pertain to personal protective equipment, application method and rate, environmental hazards, longest reentry intervals and greenhouse and indoor use directions.
4. For all other pesticides, use must comply with all label requirements including site and crop restrictions.
5. Prior to the use of any registered pesticide on cannabis, obtain an Operator Identification Number from the County Agricultural Commissioner.
6. Submit monthly pesticide use reports to the County Agricultural Commissioner.
Waste Management
1. Recycle or properly dispose of all plastic bags, containers, and irrigation materials.
2. Properly dispose of green waste in a manner that does not discharge pollutants to a watercourse. This may be accomplished by composting, chipping, and/or shredding. The method of green waste disposal must be documented.
3. Used growth medium (soil and other organic medium) shall be handled to minimize or prevent discharge of soil and residual nutrients and chemicals to watercourses. Proper disposal could include incorporating into garden beds, spreading on a stable surface and re-vegetating, storage in watertight dumpsters, or covering with tarps or plastic sheeting prior to proper disposal. The method of disposal must be documented.
4. Excess irrigation water or effluent from indoor cultivation shall be discharged to an irrigation or bio-retention treatment system, sewer, or septic system that has been properly evaluated and sized.
Water Use
1. If using an irrigation system, inspect for and repair leaks prior to planting each year and continuously during the growth cycle.
2. Irrigation systems shall be equipped with a backflow prevention devices and shutoff valves.