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.

1. Pesticide and Fertilizer Storage
   1. Pesticide and fertilizer storage facilities shall be located outside of the Riparian Corridor setbacks for structures as listed at https://permitsonoma.org/zoningcodes
   2. Pesticide and fertilizer storage facilities shall not be located within 100 feet of a wellhead, or within 50 feet of identified wetlands.
   3. Fertilizer storage facilities shall be adequate to protect fertilizer containers from the weather.
   4. Store pesticides in properly labeled and locked storage areas and protect them from weather.
   5. Store all containers of pesticides and fertilizers off the ground on pallets or shelves.
   6. 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.
   7. Routinely check for leaks and spills.
   8. Have spill cleanup kit onsite to be able to respond to any leaks or spills.
2. Pesticide Use
   1. Inspect planting stock for pests and diseases prior to planting. Avoid planting stock with pests and disease.
   2. Comply with California Food and Agricultural Code (FAC) Division 6 and 7 and Title 3 California Code of Regulations (3CCR) Division 6 as enforced by the California Department of Pesticide Regulation and the County Agricultural Commissioner.
   3. Comply with all pesticide label directions as they pertain to use sites, commodities, personal protective equipment, application rate, environmental hazards, and longest reentry intervals for outdoor, greenhouse, and indoor use.
   4. Cannabis cultivators must use registered pesticides or pesticides that are exempt from registration (FIFRA 25(b)).
   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.
3. 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.
4. 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, see the complete BMP document here: Best Management Practices for Agricultural Cultivation in the Riparian Corridor 
5. 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. 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
6. Waste Management
   1. Recycle or properly dispose of all surface trash, debris, fuels, fertilizers, and pesticides related to the operation. This includes but is not limited to; grow bags, grow containers, irrigation tubes, stakes, tags, netting, and fencing.
   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. 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.
   5. Cover compost piles with tarp or impermeable surface prior to fall rains and continuously throughout the rainy season.
7. 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. Reduce and minimize dust where appropriate to maintain soil resources on site.
   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.
8. Winterization
   1. Licensees and property owners are responsible for assuring that the cannabis operation does not result in a discharge of sediment, nutrients, pests or pathogens into watercourses or onto adjacent properties. This will be enforced through inspections conducted by the Agricultural Commissioner to verify compliance with best management practices for erosion and sediment control from cannabis cultivation sites. Winterization best management practices shall be continuously maintained throughout the rainy season. The following must be completed prior to any rain event and in place no later than November 15th: 
      
      
      • Properly apply mulch, straw, or erosion control fabric onto bare or disturbed soil.
      • Seed cover crops.
      • Remove and secure all temporary hoop house plastics and trellis netting. Polyethylene sheeting shall not be stored on the ground. Netting must be removed after harvest and disposed of properly.
      • Cover soil and/or planting media stockpiles and install berm or sediment barrier such as silt fencing or straw wattles.
      • Cover compost piles and install berm or sediment barrier such as silt fencing or straw wattles.
      • Store fuels and fertilizers in appropriate containers and covered areas with secondary containment where applicable.
      • Store pesticides in clearly labeled and locked storage areas and protect them from weather.
9. Cultivation Site Closure and Remediation
   1. Licensees or property owners shall completely clean up and remediate the site within 30 days after a license is revoked, expires, or becomes inactive. Failure to do so will constitute a public nuisance and be subject to abatement.
      
      
      • Recycle or properly dispose of all surface trash, debris, fuels, fertilizers, and pesticides related to the operation. This includes but is not limited to; grow bags, grow containers, irrigation tubes, stakes, tags, netting, and fencing.
      • For temporary hoop houses, remove and properly store hoop house frame, hoop house plastic, tarps, and poly sheeting.
      • For permanent hoop houses, remove and replace plastic, tarps, and poly sheeting as is necessary.
      • Imported soils introduced for cultivation purposes shall be removed or incorporated into garden beds.