Regulatory Review &
Cannabis Odor Management Tool
July 11th, 2025
1601 N. Imperial Ave.
El Centro, CA 92243
760-339-4969
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Cathedral City – Regulatory Review - Cannabis Odor Control Page i www.scsengineers.com
Table of Contents
Introduction................................................................................................................................... 2 Regulatory Review and Best Practices Assessment ..................................................................... 3 Regulatory Review Summary .................................................................................... 3 Background ........................................................................................................... 3 Research Process ................................................................................................. 3 Findings ................................................................................................................. 3 Case Studies & Relevance to the City of Cathedral City ....................................... 5 Regulatory Review Summary Conclusion .............................................................. 5 Odor Control Plan Development ............................................................................... 6 Cannabis Facility Type, Odor Generating Potential & OAP Requirement .............. 6 Odor Abatement Plan Outline ............................................................................... 7 Facility Description and Location .......................................................................... 7 Odor-Emitting Sources .......................................................................................... 8 Odor Control Strategies and Best Management Practices (BMPs) ....................... 8 Complaint Management System ........................................................................... 8 Section 2.0 Summary and Recommendations ............................................................................. 9 Odor Control Technology Evaluation .......................................................................................... 10 Odor Control Technologies .....................................................................................10 Change Chemical Structure ................................................................................10 Remove or Filter Odor .........................................................................................11 Neutralize or Mask Odor .....................................................................................11 Dispersion and Dilution .......................................................................................11 Section 3.0 Summary and Recommendations ...........................................................................14 Odor Control Permitting Process ................................................................................................ 21
4.0.1 Conditional Use Permit Requirements for Nearby Jurisdictions ........................21 Performance-Based Standards ..............................................................................21 Standardized Submittal Elements ..........................................................................22 Submittal Requirements ........................................................................................22 Review & Verification Protocols ..............................................................................22 Section 4.0 Summary and Recommendations ...........................................................................23 Inspection and Verification Protocols ........................................................................................ 24 Protocols and Continued Compliance ....................................................................24
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Cathedral City – Regulatory Review - Cannabis Odor Control Page ii www.scsengineers.com
Table of Contents
Inspection Protocols............................................................................................24 Demonstration of Compliance ............................................................................24 Enforcement Triggers and Subsequent Process .................................................25 Section 5.1 Summary and Recommendations ...........................................................................27 Odor Identification and Monitoring.........................................................................28 Odor Source Identification ..................................................................................28 Odor Monitoring Options .....................................................................................30 Section 5.2 Summary and Recommendations ...........................................................................36 Bibliography ............................................................................................................................... 37
Figures
Figure 1: Behavior of Odor Plume as Function of Climatic Conditions (Douglas Hamilton, 2019) .... 13 Figure 2: Examples of Field Olfactometers (Nasal Ranger, Facial Mask, Box Scentometer) ............. 33
Tables
Table 1: Odor Control Technologies Summary Table .......................................................................... 15 Table 2: Odor Control Options Relative to Source Type ...................................................................... 19 Table 3: Summary of Odor Perception Methods Via Humans ............................................................ 31 Table 4: Summary of Odor Assessment Via Chemical Surrogate ....................................................... 33 Appendices
Appendix A What is Odor?
Appendix B Example Forms
Appendix C Communication and Public Outreach
Appendix D Cathedral City Council Staff Report: Cannabis Moratorium Update Appendix E Odor Abatement Plan Template Checklists for Various Cannabis Facility Types Appendix F City of Cathedral City Licensed Cannabis Business Type and Zoning Maps
Cathedral City – Regulatory Review - Cannabis Odor Control
INTRODUCTION
With the majority of United States and the District of Columbia having legalized recreational and/or medicinal cannabis, a significant problem has emerged in several regions related to the mitigation, regulation, and assessment of the odor generated by cannabis cultivation and processing activities.
This issue is complicated as odors are subjective, and the nature and composition of cannabis odor is highly variable. In addition, different societies have inherently different levels of acceptance for odors in their communities. Regulators at the state, regional, and local levels are attempting to deal with these complex issues through a combination of permitting, land use, and nuisance rules. The cannabis odor situation in Cathedral City is no different, and currently, the municipality is working to find a balance between responsible cannabis cultivation and impacted citizens.
It is estimated that 70% to 80% of the complaints issued to regulatory agencies concerning air pollution involve an odor component (Leonardos, 1996; Nicell, 2009; Shusterman, 1992). Odor is not regulated as a pollutant by the Clean Air Act; however, may be regulated at the state or local level through various types of “odor law,” whether it is called an ordinance, rule, regulation, or policy. “Odor laws” address community odor issues in several ways and methods that utilize various criteria:
1) Annoyance (subjective categories),
2) Complaint criteria (numbers of complaints),
3) Ambient odor concentration/detection threshold (various methods), 4) Ambient odor intensity (analytical testing),
5) Ambient odorant criteria (i.e. chemical surrogate),
6) Episode duration-frequency criteria (“odor-hours”).
7) Source emission criteria (chemical surrogate at source), and 8) Best available control technology criteria (i.e. industry standard).
In the absence of "odor laws," citizens and communities often find remedies and relief in basic common-law nuisance lawsuits. Due to this regulatory approach, sources of odors may face complex permitting scenarios when addressing potential offsite odors/impacts.
SCS Engineers (SCS) has drafted this document for the City of Cathedral City (City) for the purposes of the development and implementation of effective cannabis odor control strategies. This report intends to provide guidance to City regulators regarding the current state of understanding relative to cannabis odor emissions, methods for assessing cannabis odors, and to provide guidance for regulators in establishing odor rules and permitting guidance relative to cannabis cultivation operations.
Cathedral City – Regulatory Review - Cannabis Odor Control
REGULATORY REVIEW AND BEST PRACTICES ASSESSMENT
Regulatory Review Summary
Background
Cathedral City (City) is the home to a growing cannabis industry totaling over 100 active licenses. The City’s current code outlines a general expectation that odors not be detectable beyond the cannabis business, but it fails to include the permitting, review, and enforcement standards necessary to uphold and verify compliance with City expectations. There are no required odor abatement plans, third-party reviews, regular inspections, or performance testing, making it difficult for the City to hold operators accountable when odors persist. In response, the City conducted an internal review of the current cannabis processes and regulations that revealed the need for a formal odor abatement plan, defined performance standards, and objective enforcement tools. These findings led to the initiation of a cannabis moratorium.
Research Process
On February 26, 2025, the City Council extended the cannabis moratorium by 10 months and 15 days. City staff initiated a review of 84 California cities and counties permitting cannabis cultivation that was later narrowed down to 15 cities and 3 counties that provided insight into one or more of the focus areas included zoning, odor control, licensing, and enforcement.
The research focused on how different cities handled issues like permitting, zoning and separational requirements, operational limits, odor definitions, mitigation requirements, enforcement, and response to complaints. The City also initiated a records request with the Department of Cannabis Control (DCC) to assess how many large-scale indoor cannabis cultivation facilities existed statewide.
DCC research identified six licensed large-scale indoor cultivation facilities (≥ 22,000 SF canopy), which are smaller than Cathedral City’s 200,000+ square foot C4 Industry facility.
Findings
The City’s research focused on Palm Springs, Desert Hot Springs, Coachella, and local communities within the Coachella Valley for better understanding of how each jurisdiction manages cannabis- related odor issues to support the development of a clear, enforceable cannabis odor control permitting process for the City that aligns with the best practices across California. Findings can be summarized into the following categories:
Zoning Requirements
Most jurisdictions permit cultivation, manufacturing, and testing only in industrial zones and have allowed dispensaries in both industrial and retail areas. The common zoning practices among these cities minimize cannabis-odor impacts by maintaining a zoning buffer requirement between cannabis operations and residential or sensitive land use areas such schools and daycares. Research confirmed that the City is an outlier by allowing cultivation and manufacturing in commercial zones, increasing the potential for odor complaints and conflict with neighboring zones.
Cathedral City – Regulatory Review - Cannabis Odor Control
Separation Requirements
Standard separation buffers vary across jurisdictions. For example, State law mandates 600 feet from schools/daycares/youth centers but local jurisdictions, such as Palm Springs (1,000 ft from residential), Palm Desert (1,500 ft between retailers), Long Beach (1,000 ft between dispensaries), and Grover Beach (100 ft from residential) implement stricter standards. The City does not enforce specific buffer distances between cannabis businesses and residential properties or between cannabis businesses themselves, beyond what is required by state law. The lack of the City’s separation standards enables cannabis businesses to operate closer to homes and sensitive land use areas as well as potentially create cumulative impact odor events.
Odor Control Standards
The City Code requires cannabis businesses to prevent odors from being detectable outside, but there is no requirement to submit odor abatement plans, no standard equipment guidelines, and no formal review of systems before or after installation. Most cities require cannabis businesses to install odor mitigation systems such as air filtration or negative pressure systems. Palm Springs, Coachella, and Desert Hot Springs require businesses to submit odor abatement plans, typically prepared by licensed professional engineers or certified industrial hygienists. Adopting an odor abatement standard like other cities would allow the City to have systems that are well-designed and effective.
Odor Definition
The City relies on a general nuisance definition, with odors considered a violation after three verified complaints or if observed by City staff. There are no objective tools or thresholds for measuring odor within the City ordinance. Cannabis odor is not defined precisely in most cities, but Palm Springs and Coachella use threshold-based standards involving olfactometers. Coachella also defines “odor threshold concentration” using standards from the American Society for Testing and Materials (ASTM). The Nasal Ranger is used in El Dorado and Santa Barbara County.
Enforcement & Compliance
The City can respond to complaints but does not require businesses to modify or upgrade systems following a violation. There’s currently no link between confirmed violations and CUP compliance or enforcement actions. Palm Springs uses an escalating fine structure and can revoke permits after repeated noncompliance. Desert Hot Springs authorizes daily fines for violations, while some cities require businesses to respond to complaints within specific timeframes (7–30 days).
Permitting
The City currently does not require odor abatement plans and lacks an inspection process for odor systems. Palm Springs integrates odor plan review into its CUP process with expert validation. Grover Beach requires an annual certification of odor control systems.
SCS recommends an odor abatement plan requirement for all cannabis business licensure, certified by either a Certified Industrial Hygienist or Professional Engineer. Recommendations for the framework of an OAP is outlined in Section 2.2.1.
Cathedral City – Regulatory Review - Cannabis Odor Control
Case Studies & Relevance to the City of Cathedral City
Some cities have odor control expectations written into their codes, but only a few have detailed processes for plan review, inspection, and ongoing compliance. Cities like Palm Springs and Coachella offer structured odor mitigation plan requirements but lack objective enforcement metrics.
Santa Barbara County’s recent code revisions use olfactometers but nevertheless rely on subjective assessments and complaints to drive responsive action.
Cathedral City would benefit from a structured odor mitigation plan and objective enforcement measures given the City is unique in how it permits cannabis in commercial zones and lacks measurable odor standards to highlight regulatory gaps.
Using a performance based standard places the onus on the cannabis operator/business and evaluates the system efficacy with empirical data.
Regulatory Review Summary Conclusion
When City staff compared local cannabis regulations across 15 cities and 3 counties, it was discovered that some jurisdictions have established odor control permitting processes and enforcement models, yet none had adopted objective standards for measuring cannabis odor.
Most cities rely on complaint-driven or subjective assessments, limiting consistency and effectiveness. Other jurisdictions require detailed odor abatement plans as part of the permitting process, along with engineering input and equipment specifications. These gaps highlight why the City needs expert support to create enforceable, measurable standards, outlines for what must be included in odor abatement plans, and develop checklists and procedures for inspection and enforcement.
Cathedral City – Regulatory Review - Cannabis Odor Control
Odor Control Plan Development
Odor abatement plans (OAP) contain procedures to reduce odors and include methods for managing odor complaints. The following subsections describe typical OAP contents.
Cannabis Facility Type, Odor Generating Potential & OAP Requirement
The following is a description of the various types of cannabis-related facilities, their potential for nuisance odor generation and whether having an OAP is recommended.
Cultivation Facility: Licensed premises where cannabis is cloned, propagated, grown, harvested, dried, cured, and trimmed. May include nursery (juvenile) and mature plants, or a mix of both.
Cultivation may occur indoors, outdoors, or in mixed-light environments such as greenhouses. This land use encompasses both mature plant production and nursery operations for immature plants or clones, and may involve the use of artificial lighting, environmental controls, and irrigation systems.
This facility type has a high odor generating potential and requires a robust OAP for mitigating odors generated by facility operations with an OAP checklist found in the Appendix E.
Manufacturing Facility: Licensed premises where cannabis is transformed or processed into cannabis products through chemical extraction, infusion, compounding, blending, packaging, or other preparation processes. Products may include pre-rolling, concentrates, edibles, topicals, tinctures, capsules, beverages, or other items intended for commercial sale and consumption. This facility type has a wide range of odor generating potential dependent on the nature of their operations. This type of facility requires a robust OAP for mitigating odors generated by facility operations with an OAP checklist found in the Appendix E.
Consumption Lounge: Licensed commercial establishment where adults may legally purchase and consume cannabis products on the premises in a designated, controlled environment. These lounges may be co-located with a licensed cannabis retailer or operate as standalone businesses, subject to Cathedral City authorization and compliance with state law. This facility type has a high odor generating potential and requires a robust OAP for mitigating odors generated by facility operations with an OAP checklist found in the Appendix E.
Dispensary (Retail Storefront): Licensed commercial establishment where cannabis and cannabis products are sold or delivered directly to adult-use consumers or medical patients. Retail operations may be conducted through a storefront (walk-in sales) and/or non-storefront delivery services, depending on license type and local authorization. Odor potential for this facility type is low-to- moderate, depending on product packaging, quantity and facility operations. An OAP for this facility type is recommended, with an OAP checklist found in the Appendix E.
Testing Laboratory: Licensed, independent facility authorized to receive and analyze cannabis and cannabis products for regulatory compliance. Testing includes, but is not limited to, analysis for potency, residual solvents, pesticides, heavy metals, microbial contaminants, moisture content, and terpene profiles, in accordance with state-mandated laboratory protocols. Odor potential for this facility type is low, and SCS does not recommend the City require an OAP for testing laboratories.
Cathedral City – Regulatory Review - Cannabis Odor Control
Odor Abatement Plan Outline
The following is an example outline of an effective and comprehensive odor abatement plan for a cultivation or processing facility. Appendix E includes an Odor Abatement Plan template checklists for five facility types: cultivation/processing, dispensaries (Retail Storefronts), and consumption lounges.
1) Introduction and Source Identification
Facility Name
Facility Address / Assessor’s Parcel Number(s) (APN)
Vicinity & Zoning Map
Site Map
Process Flow Diagram
Description of Operations and Layout
2) Description of Odor Emitting Activities or Processes Identification of Odor Emitting Activities and Processes Identification of Odorants
Material Storage/Waste Generation
Processes
Operational Schedules
Fugitive Sources
3) Description of Methods used for Odor Control
Administrative Controls
Engineering Controls
Process Parameters for Proper Operation
Maintenance Requirements
Staff Training
OAP plan certification by Certified Industrial Hygienist (CIH) or Professional Engineer (PE)
4) Complaint Management Procedures
Facility Contact Information
Complaint Management System
Procedures for Response
Community Outreach, if applicable
5) Corrective Action Plan, if required
Facility Description and Location
A site-specific odor abatement plan includes a description of the facility and surrounding area. The facility information includes a summary of the property size, location within the regional zoning, descriptions of the surrounding properties and land uses, dimensioned proximity to sensitive receptors, such as residential areas, schools, hospitals, daycares, and other public facilities, descriptions of type of activities taking place onsite, and a general summary of onsite structures. The presence of other potential odor-generating sites in the vicinity of the facility should also be noted.
Cathedral City – Regulatory Review - Cannabis Odor Control
Odor-Emitting Sources
The odor abatement plan includes a list of odor generating processes. The following information, where available, for the identified processes is recommended for inclusion. • Description of odor characteristics
• Odor release method (vent, building fugitives, etc.)
• Odor Controls, if any, related to the source
• Location of odor release point/proximity to sensitive neighbors • Operating schedule (continuous, intermittent, seasonal, how many weeks per each stage) Odor Control Strategies and Best Management Practices ( BMPs) The odor abatement plan describes the technologies used to mitigate odors from odor generating sources or explains why odor control is not warranted. The Plan includes a description of the odor control technology, a summary of operating and maintenance requirements for proper operation of the odor control system components, and best management practices (BMPs) the facility implements to reduce potential for offsite odor impacts. The submitted OAP shall conform in design with the City’s requested criteria and reflect a design that echoes the regulatory framework requirements.
Complaint Management System
The odor abatement plan includes procedures for responding to odor complaints. This includes identification of site-specific personnel responsible for managing complaints, and a tiered approach for responding to and mitigating complaints. An example of sections that may be included in the complaint management system is provided below.
• Method for Submittal of Complaints
o Phone, Email, Web application
• Roles and Responsibilities of Facility Staff
• Compliance Response Process
o Level 1 Response – Initial Assessment and Corrective Actions o Level 2 Response – Diagnostic Assessment and Corrective Actions o Level 3 Response -- Analytical Assessment and Corrective Actions o Level 4 Response -- Comprehensive Controls Analysis and Corrective Actions • Maintain complaint records for a minimum of five (5) years for historic analysis and data trending.
Cathedral City – Regulatory Review - Cannabis Odor Control
Section 2.0 Summary and Recommendations
• We recommend all cannabis operations submit an Odor Abatement Plan (OAP) as part of the licensing process.
o The OAP should be prepared and certified by a Certified Industrial Hygienist (CIH), Professional Engineer (PE), or otherwise qualified expert. • We recommend the City integrate odor control requirements into the Conditional Use Permit (CUP) process.
o We recommend pre-occupancy inspections and annual re-certification of odor control systems.
• We recommend the City establish clear zoning and separation standards to reduce odor conflicts.
o New cultivation and manufacturing operations should be prohibited in commercial and residential zones.
o Existing facilities in commercial zones should be subject to enhanced odor mitigation requirements to meet no detectable and offensive odor at property line standards by a reasonable person of normal sensitivity. o We recommend implementing separation buffers (e.g., 1,000 feet from residential areas) and 500 ft between licensed businesses. • We recommend adopting objective odor definitions and measurement tools to support enforcement.
o We recommend defining “odor threshold concentration” using ASTM or similar recognized standards.
o We recommend inspectors be trained to detect and differentiate cannabis related odors from other local odor sources for field-based odor assessments by staff. • We recommend cannabis businesses maintain a structured, tiered complaint response process.
o We recommend operators document all complaints and resolutions and provide records to the City upon request.
• We recommend strengthening enforcement mechanisms to maintain compliance. o Fines should escalate with repeated violations or failure to meet OAP requirements.
o We recommend linking OAP compliance to license renewals and CUP conditions.
Cathedral City – Regulatory Review - Cannabis Odor Control
ODOR CONTROL TECHNOLOGY EVALUATION
There are various odor control technologies currently on the market and many others are being vetted for use in odor mitigation from cannabis operations. From enclosed spaces, the technology of choice continues to be scrubbing the effluent point through the use of carbon adsorption technologies and/or oxidation within effluent conveyance prior to release to atmosphere.
Vapor Phase odor neutralizers have been used with some success in cultivation facilities, but this technology has limitations and is generally not received favorably by the public. We recommend that the City prohibit the use of vapor phase systems as an odor control technology for cannabis operations, as these systems have increasingly become a source of community complaints and public opposition.
Carbon adsorption systems with various pretreatment options such as Photo Catalytic Oxidation (PCO) have also been shown to be capable of significantly reducing odor emissions from cultivation and manufacturing. Air scrubbing technologies come with some drawbacks such as a high capital expense to achieve adequate coverage/treatment depending on the method of use, as well as necessitating significant power consumption.
To be effective, odor reduction should be designed specifically to the type of source, facility structure, as well as the chemical composition of the odors. The first step to controlling odor typically requires capturing and transporting the odorous compounds from the source to the chosen odor reduction device. These methods vary based on source and business type.
Capturing odors from cannabis operations will vary depending on facility type. The transportation physics of odors from outdoor cultivation are different from those produced within an enclosed or semi-enclosed space. Similarly, odors and odor generating potential from a cannabis processing facility, where there may be a lot of movement between rooms and the building envelope via doors and HVAC systems, will vary from a retail storefront with sealed and packaged goods.
Odor Control Technologies
To achieve odor control, the chemical nature of the odor compounds can be changed to make them less odorous, the odorous compounds can be removed, or other compounds can be added to neutralize the odor perception character. A brief description of odor control technologies is provided below and additional details, including pros and cons of each, are provided in Table 1.
Change Chemical Structure
Changing the chemical structure of the odorant to a less odorous compound typically requires energy input (heat), an oxidizer, or biological activity to break the bonds between the elements of the odorous compound(s). Below is a list of some common technologies that change the chemical structure of odor compounds.
• Incineration such as combustion in flares or thermal oxidizers convert odorous compounds into carbon dioxide, nitrogen and water.
• Ozone is a powerful oxidant that can break apart odorous molecules through oxidation resulting in less odorous compounds.
• Non-Thermal Plasma uses electrically charged particles (plasma) that interact with odorous compounds and break them apart into less odorous compounds.
Cathedral City – Regulatory Review - Cannabis Odor Control
• Biological Filters use microorganisms that feed off odor-causing compounds to remove the odorant from the stream. The microorganisms biologically metabolize the compound releasing less odorous compounds.
• Photocatalytic Oxidation Photocatalytic oxidation (PCO) is a process that uses light energy to activate a catalyst to break down organic pollutants, bacteria, and viruses into harmless substances. This technology is widely used in air purification, water treatment, and self- cleaning surfaces.
Remove or Filter Odor
Removing or filtering the odor from the stream to be treated reduces the outlet or effluent concentration of odorous compounds. Below is a list of some common technologies that reduce odors through filtration.
• Adsorption captures odorous molecules in the pore space of adsorbent materials, such as activated carbon or zeolite, thus reducing the odors in the process stream. • Chemical/Wet Scrubbers use highly reactive chemicals such as acids, caustics, and surfactants to react with the odorous compounds and remove them from the process stream.
Neutralize or Mask Odor
Neutralizing and masking agents do not reduce or remove odorous compounds but rather alter how the odorous compound is perceived or not perceived by a person. Below is a list of some common technologies that reduce odors through vapor phase or misting systems. • Odor Neutralizers include compounds that adhere to odor molecules and change how the olfactory system recognizes the molecule, thus changing a person’s perception of odor to that stream.
• Masking Agents are similar to perfume in that they contain synthetic fragrance that are intended to “hide” odors. In some situations, the masking agents may bind to olfactory receptors thereby inhibiting the receptor’s ability to bind to odorous molecules.
Dispersion and Dilution
Primary factors that impact the transport of odor from a stationary source include the method of release of the odors, meteorological conditions, and the local topography/location of the facility.
Odors generated in the cannabis industry are emitted through various types of release points including stacks, vessel hatches/vents, and openings in buildings or enclosures, such as doorways and ventilation points. The following characteristics can impact the transport of odor from a release point.
• Odor Emission Rate (Odor Strength): The odor emission rate is a function of the concentration of the odorous stream and the volumetric flow rate of the release. In general, the higher the odor flux, the higher the ground-level odor concentration at a downwind location.
• Release Velocity: The velocity of a release impacts both the distance the odorous molecules travel and the potential for mixing/dilution with ambient air. The faster the release, the further the odors may travel, however, there is more potential for dilution/mixing with ambient air, which can decrease perceived ground-level impacts. In general, the higher the
Cathedral City – Regulatory Review - Cannabis Odor Control
exit velocity, the lower the ground-level concentration may be at a downwind location; however, the distance odor can travel may be farther.
• Orientation of Release: The direction/orientation of an odor release impacts the transport of odor from the source. A vertical release provides the greatest potential for mixing and dilution. A horizontal release, such as a ventilation fan on the side of a building, will have limited vertical movement and reduced potential for mixing and dilution. Rain caps and hoods/enclosures around release points can also reduce the vertical movement and mixing of odor releases.
• Release Height: The height of the release will impact the amount of mixing/dilution with ambient air. A higher release point will generally lead to more mixing/dilution of an odorous source, which can decrease perceived ground-level odors. As will be discussed in Section
5.2.1, the release height can also be modified to avoid downwash from buildings, structures, and/or topography.
• Release Temperature: Although not as significant as release height or velocity, the temperature of an odorous source can impact the transport of odor. In general, the hotter the release temperature, the more buoyant the stream will be, which will increase the potential for mixing/dilution with ambient air.
The local meteorology impacts how odors are transported and mixed in the ambient air. Factors such as wind speed and direction and atmospheric stability will impact how odors are transported from a source.
• Wind Speed: Higher wind speed creates more mixing/dilution in the atmosphere and can reduce the potential for downwind odor impacts. Low wind speeds are more likely to create conditions for offsite odors.
• Wind Direction: The direction the wind blows directly impacts where the odorous release will travel. A turbulent condition, with frequent change in wind direction, can promote mixing/dilution of odors.
• Atmospheric Stability: The stability of the atmosphere influences the vertical movement of an emitted stream, which impacts the ability of the stream to mix/dilute with ambient air. In general, stable atmospheric conditions inhibit the vertical mixing of an emitted stream trapping odors close to the ground level and unstable conditions improve mixing and odor dilution.
The following figure depicts how weather affects the shape of an odor plume and the potential for mixing and dilution.
Cathedral City – Regulatory Review - Cannabis Odor Control
Figure 1: Behavior of Odor Plume as Function of Climatic Conditions (Douglas Hamilton, 2019) Stable atmospheric conditions commonly occur in the early morning hours, before sunrise, which is associated with an increase in potential for offsite odors during these periods.
Topography and larger facility structures, such as buildings and process/storage vessels, can alter the movement of wind/air around the facility and create additional surface roughness which can increase turbulence and impact the transport of odor from a source. • Topography: The topography surrounding a stationary source affects local wind patterns and surface roughness which impacts the direction odors are transported and the potential for mixing and dilution. As stated by Hamilton (Douglas Hamilton, 2019) obstacles to wind flow such as hills, trees and buildings increase the roughness of the terrain and, accordingly, the dispersion in the odor plume. Mixing is increased if winds carry the odor upslope or up-valley.
Downslope or down-valley winds lead to less dispersion and tend to concentrate odors in lower lying areas.
• Facility Structures: Similar to topographic features, facility structures alter the flow of wind around a source. As wind blows over/around a building/structure, a low-pressure area develops on the downwind side of the structure which pulls air toward the ground. Odor releases on the downwind side of this building/structure, will be affected and pulled toward the ground causing an increase in ground level odors. Increasing the release height of a source in the vicinity of a building is one method to counteract the effects of building downwash.
Use of Vegetative Buffers:
The use of vegetative buffers can provide several benefits related to the perception of odors downwind from cannabis operations. Vegetative Buffers are plantings of grasses, trees and/or shrubs that are strategically located around an odor source. Vegetative Buffers filter and trap dust, odor, particulate matter, and other molecules from the odor plume.
When used for their Vegetative Bio-Filtering and Windbreak capacities, Vegetative Buffers serve as a means of disruption of the odor plume. This allows heavier odorous molecules and odor-carrying material to settle out in areas of decreased air velocity and ‘dead spots’. Lighter molecules may lift
Cathedral City – Regulatory Review - Cannabis Odor Control
up and away. Turbulence allows fresh air from above to mix with odorous air, diluting the concentration of odorous molecules toward or below odor detection thresholds.
Vegetative Filtering Concept – Vegetative Buffers, when used for their Vegetative Bio-Filtering and Windbreak capacities, are plantings of multiple rows of grasses, trees and/or shrubs that are strategically located around cannabis facilities. This active filtering helps to reduce the odor transport and increase dilution.
Visual Screening Concept – Vegetative Buffers, when used for their Visual Screening capacity, are plantings of single or multiple rows of grasses, trees and/or shrubs. Attractive trees and shrubs visually screen cultivation activities and can serve as landscape plants to beautify the facility.
Research concludes that sources judged as “attractive” have fewer odor complaints.
The following tables include an Odor Control Technology Summary in Table 1, explaining how various odor control technologies work, along with the pros and cons of the specific technology.
Table 2 details Odor Control Options Relative to Source Type, including source type, control method, footprint, known vendors, and capital expense.
Section 3.0 Summary and Recommendations
• SCS recommends the City maintain a technology-agnostic, performance-based approach to odor control (consistent with Section 4.1) to encourage innovation, site-specific flexibility, and alignment with evolving industry best practices. • We recommend facilities prioritize design features that enhance natural dispersion and dilution to reduce odor impacts, including:
o Vertical release configurations over horizontal or obstructed vents. o Optimized release height and velocity to promote ambient mixing. o Consideration of local terrain and building downwash effects when siting odor release points.
• SCS recommends operators evaluate the use of vegetative buffers as a supplemental mitigation strategy where feasible.
• We recommend that the City prohibit the use of vapor phase systems as an odor control technology for cannabis operations, as these systems have increasingly become a source of community complaints and public opposition.
Cathedral City – Regulatory Review - Cannabis Odor Control
Table 1 Odor Control Technologies Summary Table
Odor Control
Technology How It Works Pros Cons
Vapor Phase and
Misting Systems
(e.g., Ecosorb)
• Odor neutralizer chemical processes
involved are adsorption, absorption,
gas solubility and reaction:
o Contact: Proprietary chemical
usually consisting of essential
oils is delivered into an area
affected by odors and attracts to
odor molecules.
o Adsorption: Released material
attaches to odor molecules.
o Absorption: Neutralizer
surrounds odor molecules,
potentially neutralizing their
smell.
• Most vendors advertise natural ingredients –
no hazardous materials.
• Variety of application methods (vapor phase,
atomization, additive).
• Technology has been utilized by multiple odor
generating industries.
• On-going costs of the odor
neutralizer.
• Need to select the odor
neutralizer that best reduces
odors.
• If dispersing, need the odor
neutralizer plume to intersect
the odor plume.
• Difficult to quantify odor control
benefits.
• An additional emission source of
VOCs.
• The public may be opposed to
this type of control.
Masking Agents Chemicals are sprayed into the air, using synthetic fragrances to "hide" odors.
• Masking agents can come in many scents and
cover a broad range of odors
• They can be used outside facilities so they do
not impact finished goods and can come in
non-hazardous formulas
• Technology has been utilized by multiple odor
generating industries.
• Give an immediate cover to
odors, but the odors eventually
return as the fragrance and odor
molecules separate
• Many use hazardous chemicals
and are delivered by harmful
aerosols
• The relative effectiveness of this
type of technology is
questionable.
Chemical
Scrubbers /
Packed Tower
Wet Scrubber
Odors are combined with highly reactive
chemicals — acids, caustics, oxidizers,
and surfactants within a stack or tower.
The odorous compounds chemically
react with the solution, removing odors.
• Mechanics can be monitored and carefully
controlled.
• Systems are popular: known technology with
standard, “textbook” designs.
• System efficiency not dependent on nozzle
performance.
• Effective removal performance at high odor
concentrations.
• Expensive to build; must be
operated by trained personnel
and serviced in protective gear.
• Must be designed for a specific
application, with careful
considerations for dangerous
exhaust gas.
Cathedral City – Regulatory Review - Cannabis Odor Control
Odor Control
Technology How It Works Pros Cons
• Economically treats large volumes of air
• Relatively small footprint.
• Chemicals used are considered
reactive, hazardous, and must
be neutralized before disposal.
• Requires periodic cleanings.
• Relatively tall which may create
aesthetic issues.
• Requires efficient collection of
fugitive odors to be effective.
Adsorption
(Carbon Filters)
Gas particles from the air penetrate the
pores of an adsorbent material –
activated carbon, zeolite, or silica gel –
and removes odors from the air as it
passes through.
• Carbon is porous and has a large surface area,
which allows it to absorb odors in the air.
• Activated Carbon is a common adsorbent for
organic odor removal.
• Activated Carbon is used to remove sulfur
bearing compounds, aldehydes, and ketones.
• No chemical storage or recirculation pumps
• Simple operation and maintenance.
• Can remove a wider range of compounds than
wet scrubbers.
• Removes VOCs.
• Reversible in nature, which
allows odors to return if heated.
• Spent media disposal can be
messy and expensive, especially
when it contains hazardous
compounds.
• Adsorbents are consumable and
must be re-activated or
replaced.
• As influent odor increases,
carbon bed life expectancy
decreases.
• Systems can lose effectiveness
in highly humid environments.
Ozone
Generators create ozone molecules,
which are highly reactive to organic
material.
• Ozone is a powerful oxidant and anti-microbial.
• Ozone is fairly inexpensive to generate.
• Systems do not require filters.
• Can cause side effects if used
around people; treated areas
must be evacuated while in use
and hours afterward.
• Extremely caustic and could
damage cannabis products or
react to other chemicals in
treatment areas.
• Not effective on inorganic odors.
Cathedral City – Regulatory Review - Cannabis Odor Control
Odor Control
Technology How It Works Pros Cons
• Must be utilized within a duct or
stack to protect workers and
plants.
Biological Filters
Contaminated air passes through soil,
compost, wood chips, or other organic
material. As the odorous air flows
through the material, pollutants
(including odor molecules) transfer into a
thin biofilm on its surface.
Microorganisms in the biofilm eliminate
odors.
• Bacteria used are naturally occurring and can
metabolize many organic odor-causing
compounds.
• Works on odors that are biodegradable and
water-soluble.
• Easy to maintain and do not require chemical
addition.
• Can also remove VOCs.
• Large units with massive
footprints are needed to treat
airflow.
• Microbes must interact with the
odorous compounds over long
periods.
• Material must be replaced,
causing odors to go untreated
during downtime. Typical rebuild
is every 3-5 years.
• Installation costs can be
significant
Biological
Oxidation
(Scrubber)
Air is forced upward through an
adsorption column filled with synthetic
material. Water containing
microorganisms circulates through the
system, feeding off odor-causing
compounds and releasing cleaner air.
• These units work well to reduce odors caused
by ketones, alcohols, and ethers.
• Requires lower detention times (8 to 15
seconds for H2S) than bio filters.
• Media can be stacked higher.
• Inert media have a long bed life.
• Reduces potential footprint and requirements
for media replacement.
• Equipment needed to
recirculate water in
bioscrubbers makes for
expensive up-front and
operating costs.
• Requires selection of lab-
developed bacterial strain
specific to odor causing
chemicals.
Thermal &
Catalytic
Converters
The system burns odorous gases, The
gas is passed over (or through) catalytic
materials, converting residual gases into
compounds like carbon dioxide, nitrogen,
and water.
• There has been widespread development for
different catalytic mediums, mainly for
“reduction” and “oxidation” catalysts.
• Can potentially introduce toxins
and noxious substances into the
air.
• Even for well-designed and
operated systems, there is a
need for catalyst saturation and
sterilization.
Cathedral City – Regulatory Review - Cannabis Odor Control
Odor Control
Technology How It Works Pros Cons
Incineration
(Catalytic,
recuperative,
regenerative)
Odor-causing waste and gas are burned
at high temperatures supposedly
destroying process odors.
• Incinerators are one of the most positive and
proven methods for destroying VOCs with
efficiencies up to 99.9999%.
• Recuperative incinerators are usually more
economical than straight thermal incinerators
because they recover about 70% of the waste
heat.
• The incineration process is effective against
organic odors.
• Can also use modified incineration method to
produce Biochar with cannabis waste to reuse
as soil additive.
• High initial cost.
• Supplemental fuel requirement.
• Dangerously high temperatures
— usually around 1472°F
(800°C)— are needed to destroy
odors.
• Potentially introduces toxins and
additional odors into the
atmosphere.
• Additional air is sometimes
required and can cause volatile
gases to be released from the
waste gas.
• Not well suited to streams with
highly variable flow because of
reduced residence time and
poor mixing during increased
flow conditions.
• May not be suited for sulfur
containing compounds due to
formation of highly corrosive
acid gases.
Fabric Filter
(Mechanical
Shaker, Pulse-
Jet, Reverse-Air)
Gas is passed through a tightly woven
fabric, causing particulate matter (PM) in
the flue gas to be collected on the fabric
by sieving and other mechanisms.
• High collection efficiencies (95%+) of
particulates.
• Corrosion and rusting are not typical problems.
• Operation is relatively simple.
• Typically, does not require high voltage.
• Available in a large number of configurations.
• Useful for collecting particles with resistivities
either too low or too high for collection with
electrostatic precipitators.
• Potential for flammable dust.
• High temperatures require
special refractory mineral or
metallic fabrics which can be
expensive.
• Relatively high maintenance
requirements (e.g., periodic bag
replacement).
• Fabric life may be shortened at
elevated temperatures and in
the presence of acid or alkaline
particulate or gas constituents.
Cathedral City – Regulatory Review - Cannabis Odor Control
Table 2 Odor Control Options Relative to Source Type
Source Type Control Method Footprint Vendors
Effectiveness (%)*
Capital Expense High Low
Controlled
Stacks (Indoor
Cultivation and
Processing
Facilities, Non-
vented
Greenhouses)
Non-Thermal Plasma
Oxidation
Small - Placed on
Stacks IONOX 90% 65% Medium
Regenerative
Catalytic Oxidizers
(RCO)
Anguil 95% 80% High
Bio Filters
Large Footprint
Evoqua 95% 70% Medium
Envirogen 95% 70% Medium
Bio-Scrubber/Bio
Trickling Filter
Vertical Design
Evoqua 95% 70% Medium
Envirogen 95% 70% Medium
Chemical Scrubber
Horizontal or
Vertical Design,
Compact
Valkyrie System by
Streamline 95% 75% Medium
Molecular Filtration -
Carbon
Horizontal or
Vertical Design,
Carbon Bulk 95% 80% Medium
General Carbon 95% 80% Medium
Camfil 95% 80% Medium
Byers Scientific 95% 80% Medium
Multi Technology
Scrubber Systems
that include TiOx
Horizontal or
vertical Design Envinity Systems 98% 80% Medium
Vapor Phase
Neutralizer or Mask
Small footprint
OMI
Not
Available
Not
Available Low
FogCo Not
Available
Not
Available Low
Cathedral City – Regulatory Review - Cannabis Odor Control
Source Type Control Method Footprint Vendors
Effectiveness (%)*
Capital Expense High Low
Byers Scientific Not
Available
Not
Available Low
Vents
(Vented
greenhouses,
indoor
cultivation)
Internal Treatment -
Scrubber Towers Envinity, Camfil 95% 80% Medium
Misters Essential Oils Byers Scientific Not
Available
Not
Available High
Vapor Phase
Essential Oils OMI Not
Available
Not
Available Low
Iodine Based
Solution Fog Co Not
Available
Not
Available Low
Fugitive
(All Source
Types)
Misters Small - 6'X6 Multiple
Not
Available
Not
Available Low
Vapor Phase
OMI Not
Available
Not
Available Low
Fog Co Not
Available
Not
Available Low
Product
Storage/Waste
Treatment
Additive To Treated
Chemical Tanks,
pumps OMI Not
Available
Not
Available Low
Ph Control Chemical Tanks,
pumps Various Not
Available
Not
Available Low
Talon Sulfide
Elimination System
Chemical Tanks,
pumps Streamline Not
Available
Not
Available Low
* Values presented are from manufacturer literature and general research. SCS has not validated all of the listed specifications and ranges presented within cannabis operations.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com
ODOR CONTROL PERMITTING PROCESS
Based on our comparative review of odor control permitting programs in peer jurisdictions and our direct experience developing odor abatement plans across the cannabis and broader industrial sectors, SCS recommends that the City adopt a permitting structure that clearly assigns the responsibility for demonstrating effective odor control to the cannabis operator. This approach promotes innovation, introduces accountability, and provides the regulatory flexibility needed to accommodate site-specific conditions. To support this structure, we recommend the following foundational components.
4.0.1 Conditional Use Permit Requirements for Nearby Jurisdictions Below is a concise comparison of Conditional Use Permit (CUP) frameworks across selected Coachella Valley agencies as well as other relevant jurisdictions.
City CUP Requirement Odor Control Specifics Enforcement Palm Springs Mandatory Operating plans, filtration,
inspections Permit suspension/inspection
Desert Hot
Springs Mandatory Detailed odor equipment in
CUP, annual renewal Permits revoked if non-compliant
Coachella Mandatory Time/place/manner review,
odor part of hearings Local discretion
Palm Desert CUP + regulatory
permit required Filtration implicitly required Standard CUP enforcement Grover Beach Mandatory
Uses County CUP standards,
detailed odor equipment with
annual recertification
Permit/business license suspension
Santa
Barbara Co. Mandatory
Detailed OAP with carbon
scrubber use requirements,
vapor phase / misting ban
Nasal ranger enforcement, penalties,
operational compliance required,
legal precedent for lawsuits
Performance-Based Standards
Rather than mandating specific odor control technologies, SCS recommends a technology and manufacturer agnostic approach where the City adopts a performance-based standard for odor control. This approach allows operators to select and propose systems best suited to their facility design and odor sources. The performance-based standard also provides flexibility for technological innovation as the odor control technology industry continues to evolve rapidly and new systems are tested for efficacy, introduced into the marketplace and system costs vary widely depending on the size and scope of the facility operations. This method also simplifies regulatory enforcement by focusing on measurable outcomes (e.g., verified odor complaints, odor sample testing following system introduction and improvements). Adopted standards should conform with considerations outlined in Section 5.2.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com
Standardized Submittal Elements
A standardized submittal checklist has been provided in the appendix to assist in streamlining the permit review process and maintain consistency across applicants. The checklist includes substantial considerations for submittal review for any cannabis facility type. Key insights from OAP reviews include:
• Details on the facility and the supporting operations. • Vicinity and facility maps with proximal sensitive receptors and accurate distances and dimensions.
• Detailed specifications for all odor mitigation equipment, including manufacture make/model, quantity, flow capacities, media types, system configurations and control points.
• A narrative description of the site-specific odor mitigation strategy, explaining how the selected controls address potential odor sources under typical and worst-case conditions. • Maintenance schedules and media replacement intervals, with justification tied to manufacturer recommendations, specs or operational history. • Testing and sampling procedures, if applicable, ensuring system efficacy. • Engineering drawings or system schematics that depict the physical layout of odor control infrastructure within the facility, where odor controls are installed and how they integrate with ventilation systems.
Submittal Requirements
Ensuring technical credibility of the submitted odor abatement plans, the City should establish minimum qualifications for third-party consultants or engineers preparing the plans. This standard improves the quality and defensibility of submitted plans, reducing staff burden and ensuring fair expectations for applicants. Qualifications should include:
• Documented experience in designing or evaluating odor mitigation systems. • Certified Industrial Hygienist (CIH) or Professional Engineer (PE) licensure. • References demonstrating successful implementation or review of odor control system in cannabis or similar industries.
Review & Verification Protocols
SCS recommends the City adopt a formal review and verification process that includes an initial technical review to assess the completeness and adequacy of each OAP submission, including conformance with the checklist requirements and adherence to performance expectations. This process can be documented in internal review guidelines or codified as part of the permit ordinance or conditions of approval.
We also recommend field inspections and/or odor monitoring as needed to verify implementation and effectiveness. Having triggers for plan updates is also important as operational changes, technology upgrades, and/or documented odor complaints suggest underperformance, should also be in place. We recommend technical OAP update and review following any substantive improvements or changes to the facility including:
• Following odor control system modifications or changes in quantity, type, or operational adjustments to system.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com
• Following facility improvements, adding or removing processes, site renovations, tenant improvements, or any other activity that alters the odor control system or odor generation at the facility.
• OAPs should be updated and resubmitted reflecting the system/facility changes and indicate that the system functionality continues to address on-site odor control.
Section 4.0 Summary and Recommendations
• We recommend the City adopt a permitting structure that places responsibility for demonstrating effective odor control directly on cannabis operators. • We recommend Conditional Use Permits (CUP) require formal Odor Abatement Plans (OAP) for all cannabis facilities, consistent with regional best practices. • We recommend the City adopt a performance-based odor control standard, rather than mandating specific technologies.
o Operators would be responsible for selecting and implementing odor control systems that meet measurable performance outcomes (e.g., verified odor reduction, complaint thresholds).
o This technology-agnostic approach provides flexibility for innovation and scalability across facility types and sizes.
• We recommend implementing standardized submittal requirements to promote consistency, efficiency, and defensibility in plan reviews. • We recommend the City establish minimum qualifications for third-party consultants preparing OAPs to maintain the integrity of technical evaluation. o We recommend requiring CIH or PE licensure and documented experience with odor mitigation in cannabis or similar industries.
• We recommend the City adopt a formal review and verification process for submitted OAPs.
o Initial technical reviews should assess plan completeness, adequacy, and conformance with City standards.
o We recommend incorporating field inspections and/or odor monitoring to verify proper system installation and initial baseline performance. This can be performed by a third party.
• We recommend establishing clear triggers for OAP updates to reflect operational or facility changes, including:
o Modifications to odor control systems (equipment quantity, type, or settings). o Facility expansions, process changes, tenant improvements, or activities that alter odor generation.
o Updated OAPs should demonstrate continued system effectiveness and alignment with performance-based standards.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com
INSPECTION AND VERIFICATION PROTOCOLS
While there is no single molecule that represents “odor” and can be easily targeted or measured in real time, there are a range of identification and measurement tools to objectively identify odors.
Cannabis odor inspections in Cathedral City shall be governed by scientifically grounded procedures that include qualitative odor assessment, quantitative odor measurement, and source identification, using sample collection and dispersion modeling as necessary. These inspections serve as the basis for determining compliance with City regulations, issuing violations, and enforcing corrective actions.
All inspections shall be carried out by City personnel trained in odor verification techniques or qualified third-party assessors approved by the City.
Protocols and Continued Compliance
Inspection Protocols
Section 5.2 below expands on a host of options for monitoring and assessment methods related to odor. General audits and inspections should be done annually, or at a frequency determined by the City, at each facility to align all businesses to the same consistent performance standards, confirm all systems are operating properly, respond to changing conditions, and provide a paper trail of ongoing compliance. In short, compliance checks are used to confirm that operators and their employees are knowledgeable about the odor mitigation strategies they are employing. Appendix B contains an example Audit Form for items necessary to review during site visits. Items pertinent to audits, regardless of business type, include but are not limited to:
• Noting any observations of odors at the facilities property line or at adjacent properties; • Reviewing facility diagrams for completeness:
o Are odor control systems, exhaust points, negative pressure systems, etc labeled on the map/facility diagram?
o Is the map accurate?
• Inspecting each systems performance and identifying opportunities for maintenance such as clearing dust from intakes, replacing loaded filters based on manufacturer’s recommendations, or tightening fittings;
• Checking for leaks in the building envelope.
Demonstration of Compliance
While Audits verify that the systems in place are in operation, performance testing or third-party verifications assess operational effectiveness. Requirements for these depend on cases such as:
• Documentation of inconsistencies or repeat violations in multiple audits; • When discrepancies arise between visual inspections of system conditions and planned controls during an audit;
• After equipment modifications and upgrades, or facility layout changes; • Prior to or immediately after the commission of new equipment or systems.
The frequency of and requirements for internal audits and compliance checks should fall under the management of the facility. We recommend quarterly internal verifications for odor control and air filtration system performance, including required documentation of routine maintenance checklists and filter replacements. The schedule and methods for internal verifications should be included in the facilities OAP. Routine odor monitoring provides facilities with defensible documentation of performance and enables them to demonstrate a proactive approach to odor management and regulatory compliance.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com
Enforcement Triggers and Subsequent Process
Regulations should not rely solely on complaints or triggers to elicit action, and odor audits or verifications should occur on a frequency defined by the City; however, verified complaints can drive action, and an example complaint verification, investigative, and corrective action process would look like this:
Stage 1 – Log Complaint Data (and build a Predictive Odor Window) • At a frequency defined by the City, complaint data will be reviewed to gather time-of-day and day-of-week patterns from odor complaints. These will be overlayed with historical wind patterns and weather conditions. This creates a Predictive Odor Window (POW). • With the POW defined, the City will conduct inspections in the POW. This allows the City to conduct targeted inspections as opposed to reactive enforcement, and provides objective verification.
• If staff observations match ongoing complaints during the POW, continue to Stage 2. o Residents and stakeholders generally expect a quick response, so public communications from the City regarding the non-reactive timeframe and benefits of this Predictive Program will be important.
Stage 2 – City Response
• City personnel or a City appointed representative will conduct in-field investigation(s) of odor surrounding the Facility in question using an Odor Assessment method listed in Table 3.
Observations must be documented in a standardized form noting the inspector’s name, location of observation, weather conditions, and time of observation. This method must be consistently utilized once chosen and written into the cannabis ordinance. The window of time during which the in-field investigation takes place must align with the POW’s specified timeframe.
o Based on the June 17, 2025 call with the City, direct olfactory observation is the preferred method of identifying odor and determining compliance with the “No Odor at the facility property line” requirement.
• In the field, investigations will be made downwind of the facility at the property line or 100ft downwind of the building edge, dependent on accessibility. o The detected odor must be characteristic to its distinctive operation. o If odor is NOT detected, the process of investigation for the facility in question, initiated by the complaints that created this specific POW is complete. o If odor IS detected, continue to Stage 3.
Stage 3 – Corrective Action
• The facility in question will be issued a Corrective Action Notice (CAN) by the City within three (3) business days of a failed inspection. The Operator shall submit a Plan of Action within seven (7) calendar days, detailing the problems identified, Corrective Actions to be taken, and establish a timeline for implementation. Corrective actions shall be implemented within three (3) weeks of the original CAN, unless otherwise approved by the City. o Should these deadlines not be met, a fine, as determined by the City, shall be imposed.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com
o An example Plan of Action is included in Appendix B.
• Once the mitigation deadline is met, in-field investigations as listed in Stage 2 will be repeated.
o If odor is NOT detected, the process of investigation for the facility in question, initiated by the complaints that created this specific POW is complete. o If odor IS detected, repercussions as determined by the City will be implemented.
Continue to Stage 4.
Stage 4 – Third Party Mitigation
• The Facility in question will consult with, and retain as necessary, a third-party odor consultant at the operator’s expense, to mitigate the nuisance odors by a deadline implemented by the City. This could include, but is not limited to, implementing or revising an Odor Abatement Plan, installing approved Odor Control Technologies as listed in Table 2, conducting odor source identification to directly target and address the source, etc. Chemical surrogates used to measure odor in real time, as listed in Table 4, could also be implemented by the Facility in this Stage as a preventative measure or as a measure of defensibility.
o Qualifications for the third party must meet minimum levels of competence. In addition to understanding odor dynamics, examples of competencies may include, but are not limited to:
Completion of an Odor School program
Certification as an Industrial Hygienist (CIH)
Licensure as a Professional Engineer (PE)
o Defensible methods in addressing odor source and receptor perception are listed in Section 5.2.1.
• Once the deadline is met, in-field investigations as listed in Stage 2 will be repeated. o If odor is NOT detected, the process of investigation for the facility in question is complete.
o If odor IS detected, harsher repercussions, as determined by the City, will be implemented. Stage 4 shall be repeated until odor is no longer detected, or until continued noncompliance results in revocation of the license.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com
Section 5.1 Summary and Recommendations
• Recommended frequency for site Audits are annual
o Audit notes: As a reference point, carbon filters are typically replaced every 3 to 6 months in high load environments but can extend to roughly a year based on specific use. Prefilters are typically replaced monthly. We recommend spot checking scrubbers and referencing maintenance logs to verify. • Building a Predictive Odor Window (POW) and inspecting a facility in that window is recommended in addressing complaints. This is a targeted approach as opposed to reactive and will prevent the City from being first responders. • Screening complaints:
o The City will screen complaints, or contract a third-party complaint management firm, to track and analyze:
Complainant name and contact
Exact date and time of odor event
Location
Odor character
Duration
Strength (faint, moderate, strong)
Meteorological data (if available)
• We recommend the inspector take precise notes. Observations should occur downwind of the Facility in question. If observed odors are upwind, odor could be attributed to other operations. The precise location is vital in collecting complaint information; the address alone is not sufficient.
• We recommend the inspector to have a handheld anemometer to detail wind conditions during inspections.
• We recommend inspectors come equipped with a filtered mask, to avoid “nose fatigue” or “nose blindness”. They should wear the mask in between observations and take necessary breaks.
• In areas with a dense concentration of cannabis operations where odor is detected at the property line, the burden should shift to the operator to demonstrate compliance (e.g. maintenance records, odor control data). We recommend operators have wind sensors onsite to provide supplementary data.
• We recommend incremental increases in fines should proper documentation not be submitted to the City or deadlines are not met.
• We recommend the enforcement language be changed to be more flexible, e.g. “No operator shall cause or allow the release of cannabis-related odors beyond the property line of their facility that are detectable and offensive to a reasonable person of normal sensitivity, as determined by the City.”
• We recommend the City schedule the follow-up inspection within 30 days after the Corrective Actions have been implemented.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com
Odor Identification and Monitoring
The below sections are listed for informative purposes for the City, while responsibility to carry these out should fall under the facility and their chosen third-party consultants.
Odor Source Identification
To confirm the source of detected odors, SCS recommends that all facilities engaged in cultivation, manufacturing, or processing install and maintain an onsite Meteorological (MET) system capable of recording wind direction and wind speed. Retail and distribution facilities should be exempt from this requirement due to their significantly lower odor mitigation needs; however, if an inspection is failed, operators may be required to install and maintain an onsite MET system at the City’s discretion. MET sensors must be calibrated at least annually, and all collected data shall be archived and accessible for a minimum of two years.
Real-time and historical MET data in conjunction with operational logs and complaint timing will be used to assess source attribution. In areas with multiple cannabis operators, facility-specific odor logs and equipment performance records may be used to differentiate responsibility.
Below is a list of typical information compiled for identified odor sources:
• Location
o Coordinates
o Proximity to buildings/structures
• Release height
• Release dimensions
o Surface area/diameter
o Velocity or flowrate
o Temperature and pressure
o Release configuration details (rain cap, horizontal release, partial enclosure…) • Operating schedule (by hour)
o Continuous, hourly fluctuations, seasonal fluctuations, etc.
Sample Collection and Analysis
When field inspections do not produce conclusive results or are subject to dispute, the City may require air sample collection. Tedlar bags are typically recommended for collection due to their effectiveness in preserving volatile organic compounds and sulfur compounds associated with cannabis odor. Samples shall be analyzed using ASTM E679 and ASTM E544 by an accredited laboratory, or by using the European Standard EN 13725. For analysis via all methods, samples should be analyzed within 36-hours of collection for sample integrity.
Air samples shall be collected at the facility boundary and, where applicable, from ridge vent or effluent locations during periods of anticipated maximum odor generation. Sampling should be scheduled based on production cycles, meteorological forecasts, and historical complaint data to capture peak emission periods. All samples must be collected while the facility is operating under normal conditions and in accordance with standard operating procedures to present representative results.
During onsite sample collection, additional data that may be collected that can assist in the odor assessment are below:
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com
• Meteorological conditions during sample collection: wind direction, speed, atmospheric condition, precipitation
• Operating conditions during sample collection: what equipment is operating, operating throughputs, equipment condition (obvious issues)
• Ambient upwind and downwind samples for odor analysis • Measurements/analysis of potential odor surrogates, such as Total Reduced Sulfurs.
Odor Emission Rate
In cases of repeated violations or where corrective action plans are incomplete or disputed, the City may mandate source testing of odor emission rates.
The odor emission rate, source strength, is calculated for the identified odor sources by multiplying the odor concentration by the volumetric flow rate (in units of m3/s) of the release point. Volumetric flow rate for a point source (e.g., stack or vent) is:
• Calculated by the product of the air velocity in the stack/vent/duct and the cross-sectional area; or
• Obtained from equipment specifications, source testing reports, permit applications, or other documentation.
Volumetric flow rate for a non-point source (e.g., fugitive emissions) is estimated using engineering calculations, air velocity meters, and/or advanced measurement techniques such as a sampling hood (flux chamber).
Odor Dispersion Modeling
An atmospheric dispersion model is used to estimate off-site odor concentrations resulting from the source(s) identified from facility operations. The American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) is an often-used model by regulators, environmental consultants, and professionals for this type of modeling. Required input data for AERMOD includes:
• Odor source parameters (i.e., emission rate, dimensions, flowrate, temperature, pressure) • Odor source operating parameters (continuous, daily limits, seasonal limits, annual limits) • Building downwash parameters (building dimensions and heights) • Meteorological data (upper air and ground level – sources from National Weather Stations) • Terrain data (i.e., National Elevation Dataset terrain data files) • Receptors (locations the model will calculate odor concentration at – user specified) • Model options (specifics on dispersion options selected by user)
5.2.1.3.1 Model Results
AERMOD estimates the maximum odor concentration (D/T value) for the receptors (locations) included in the model. The model can be configured to output combined impacts from a facility as well as the odor impacts from individual onsite sources. The peak offsite odor concentration can be identified and then compared to an appropriate nuisance odor threshold for the region. For example, odors may be classified as a nuisance at or above 7 D/T. In addition, the modeling results can be processed into odor concentration contours that are overlaid onto aerial maps of the study region.
These contours help identify any offsite areas where estimated impacts exceeded the applicable nuisance odor threshold. If the predicted off-site impacts exceed the nuisance odor threshold selected, then additional modeling runs can be performed to identify the sources driving the results
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com
as well as the amount of mitigation (i.e., reduction in odor emission rates) for predicted impacts to be below the nuisance odor threshold.
5.2.1.3.2 Model Limitations
A limitation and challenge when using air dispersion models to estimate odor impacts is the time and space resolution the model is based on (Nicola Pettarin, 2015). The smallest increment of time typical air dispersion models calculate results on is one hour, while it takes a few seconds for a person to inhale and perceive an odor. This is a large discrepancy between what the model will estimate and what a person may perceive. Furthermore, a modeled hourly average will not mimic a short-term increase in odors from a source, such as unloading a mature cannabis flower delivery over a 10-minute period. During the 10 minutes of unloading, there can be an increase in odors from the activity that will not be seen in the model results.
Odor Monitoring Options
Odors are a perception experienced when chemicals come into contact with odor receptors on olfactory nerves. This perception is quantified using an odor detection threshold defined as the theoretical minimum concentration that incites an olfactory response or sensation (defining 1 odor unit, or 1 OU), and varies by population based on the below factors. Whether an odor is perceived as a nuisance depends on those factors, and sets the framework for criteria that can be used to assess odor impacts in the field and supports consistent decision-making in enforcement • Odor quality: odor results stemming from a pure compound tend to have a higher threshold (less offensive) than a mixture of compounds.
• Odor frequency, timing, and duration: when and how an odor is perceived within a community affects the annoyance and offensiveness of the odor. • Population Sensitivity: individuals have a range of sensitivity to odors. This is affected by past experiences and previous exposures, as well as individual association with the odor. Some of the population may find certain odors pleasant, while other members of the population may find them offensive. This factor appears to be especially true relative to cannabis odor. • Background Level: background odors can affect the degree to which a specific source contributes to a cumulative impact.
• Public Expectation: the relative level of community tolerance to an odor. For example, farming communities may consider a background level of odor to not be offensive even at high concentrations while residents of other communities find the same odors offensive even at low concentrations.
• Source Characteristic: how the odors are emitted is an important factor. Controlling odors from a point source is significantly easier to control than odors from an area or diffusive source.
It’s important to note that the odor detection threshold (DT) is lower than the recognition threshold (RT). The recognition threshold is the point at which the panelist(s) recognize the character of the odor. In addition, the annoyance threshold is higher than the recognition threshold.
Odor perception varies among individuals and direct assessment of odor perception relies on human olfactometry for determination of odor impacts. Increasing the number of humans and observations helps to normalize variations in individual odor perceptions. Known methods of quantifying and measuring odor are limited; and each method is associated with a series of pros and cons related to use case, quantification, and cost. Methods of assessing odors vary between those that utilize human perception or chemical surrogates. This section will go into depth on each. Brief summary tables for each category are provided below.
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Qualitative Assessment
Qualitative odor assessments involve evaluation by trained personnel in response to public complaints or as part of scheduled inspections. These inspections rely on the perception of cannabis odor character at a facility property line or adjacent building/facility. An inspection may be triggered by verified odor complaints from separate individuals within a set period.
Complaints will be cross-referenced with meteorological (MET) data to verify alignment with wind direction and facility operations at the time of the reported incident. Inspections initiated from complaints will only proceed when the complaint’s timing and location are consistent with MET data and there are enough complaints to meet critical volume to develop a POW.
Inspectors must identify if cannabis odor is perceptible at the facility property line, provide a value on a scale from 1-5 on the odor intensity, describe the odor character using consistent terminology, record wind and atmospheric conditions, and confirm that the facility was operational at the time of the incident. Observations must be documented in writing and supplemented with photographs and site sketches where applicable.
Quantitative Assessment
Quantitative assessments may use calibrated field olfactometers or odor panels to measure odor concentration. This determination must be supported by sensory descriptors and MET data alignment with facility operations. Measurements must be taken under stable wind conditions of at least 1.5 miles per hour. All data, including odor character, D/T values, GPS locations, and meteorological readings, must be recorded.
Odor Assessment via Human Perception
A summary of the methods odor can be perceived/measured is provided in the table below with further details in the following sections.
Table 3 Summary of Odor Perception Methods Via Humans
Odor Perception
Method:
Measurement
Units:
Benefits: Limitations:
Direct
Observation
None, Scale of
odor
Perception (i.e.
1-5)
Inexpensive, Observations
can be made anywhere a
human can be present.
Objective, qualitative only,
significant potential for bias.
Field
Olfactometer
Dilutions to
Threshold
Ratio
Relatively inexpensive, field
deployable, somewhat
quantitative.
Limited quantitate value,
requires trained personnel,
subject to bias, olfactory
conditioning probable, does
not determine source of odor.
Odor Panel
(ASTM Method)
Dilutions to
Threshold
Ratio,
Intensity,
Character
Highly quantitative,
panelists are unbiased,
panelists do not know
source type or location,
Vetted American Society of
Testing and Measurements
Method (ASTM).
Repeatable and proven.
Logistically constraining as
odor panel needs to be
reserved in advance of
measurements, samples
should be analyzed soon
(within 30 hours) after
sampling. Observations are
conservative (higher) than
that of general population.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com
Can be expensive if large # of
sampling points and/or times
are necessary.
Direct Observation
No methods currently are available that appropriately simulate or quantify complex odors. Thus, it is difficult to predict human responses to exposures of chemical mixtures. The human nose is, to this day, the most suitable ‘sensor’. There is currently no substitute for assessing odor perception of complex sources than direct human perception. Direct Observation, however, is highly subjective. An individual is subject to biases such as background odor, familiar odors, or simply being an individual with either a heightened or decreased sensitivity to smell, among other biases. Additionally, these observations are only qualitative and do not provide a quantitative measurement that is repeatable.
Field Olfactometers
Olfactometers, invented over a century ago, operate on the principle of diluting odors. The amount of dilution required to reduce an odor sample below detection represents the strength of an odor.
The Nasal Ranger® and Scentometer are specific types of olfactometers commonly used by regulators for field assessments. They are portable odor measuring device that combines odor detection with odor quantification. Odor quantification is determined by the Dilutions-to-Threshold ratio, or D/T. This ratio is a measure of the volume of carbon-filtered air needed to make a volume of odorous ambient air non-detectable. Users must breathe through the device at a flow rate of 16 – 20 liters per minute (LPM) when using the device. Users of the Field Olfactometers must be trained and certified via a specific training course provided by their respective manufacturers.
Field use examples include:
1. On-site monitoring—for monitoring of various on-site procedures and operations,
2. Random monitoring—for monitoring correlating with meteorological information and on-site activities,
3. Intensive odor surveying—for determining sources and operations that cause odor,
4. Citizen monitoring,
5. Complaint response
6. Permit compliance, and
7. Plume profiling.
While field olfactometers are portable and offer multiple field use examples, there are some biases inherent to this method that are not present in olfactometry performed through the use of an odor panel. Because field olfactometers are deployed and used in the field, the operator is subject to field conditions and has already biased himself, his nose, and olfactory senses with the ambient air on location. In many cases, the human nose can become accustomed to an odor after a period of exposure and become “nose-blind” to the odor(s) under evaluation. Thus, using the Nasal Ranger® or field Scentometer to determine in-field D/T can have a low bias on the results.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com
Figure 2: Examples of Field Olfactometers (Nasal Ranger, Facial Mask, Box Scentometer) Odor Panel
Using an odor panel on the other hand, removes the field environment bias seen with usage of the Nasal Ranger®. This method uses a stationary olfactometer that operates on the same principle as the Nasal Ranger®. Olfactometers generally have four (4) to six (6) stations for human panelists.
Each station is equipped with two (2) to three (3) sniff ports. One (1) random sniff port produces a stream of diluted odorous sample air, while the other port(s) produce a stream of pure air. Ideally, stationary olfactometers are located in an odor-free room, where panelists are asked to determine which port contains the odorous air. The dilution at which at least half the panel correctly and confidently identifies the correct port determines the D/T measurement of that sample of air. This is an objective method developed to establish odor concentration using human assessors.
The major constraint to this method is logistics. Generally, panels need to be booked in advance, and they can only handle a certain quantity of odor samples due to both time and panelist fatigue.
Additionally, odor samples have a holding time of 36 hours, so samples must be shipped to the odor lab via overnight courier, which can be costly.
Odor Assessment via Chemical surrogate
A summary of methods to assess odor through chemical surrogates is provided in the table below with further details in the following sections.
Table 4 Summary of Odor Assessment Via Chemical Surrogate Analytical
Measurement
Measurement
Units:
Benefits: Limitations:
Time Averaged
Samples with
follow-up Analysis
via Analytical
Laboratory
Dependent on
Method
Many compounds can be
detected to ppb level
accuracy.
Costs are per sample and can
be expensive. The sample only
represents the time and
location the sample was
collected. Field labor
dependent and requires
sampling expertise. No single
analytical method will cover all
odor causing emissions.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com
Analytical
Measurement
Measurement
Units:
Benefits: Limitations:
Total VOC
Detection w/
Photoionization
Detectors (PID)
Parts per billion Inexpensive analyzer
measures for total VOCs.
Fast response time and is
capable of real-time
measurements
Does not differentiate between
VOCs, Calibrated based on
single VOC that may be very
different from compounds of
interest. Responds to VOCs that
can exist in high background
concentrations. Many VOCs are
not significant contributors to
odors.
Field Deployable
GC w/ Various
Detectors
Parts per billion Accurately identifies and
quantifies concentrations of
multiple target compounds.
Can collect and measure
samples every 10 minutes
depending on the specific
compounds of interest. Can
be adapted to measure at
multiple sampling locations.
Limited detection to
compounds of similar retention
times under current
configuration. Calibration
standards are field-generated
or need to be created by
certified labs relative to the
compounds of interest. GC
system set up for terpene
analysis currently do not detect
any organosulfur compounds of
interest. The concentration of
measured VOCs relative to odor
concentration is not always
suitably correlated.
Electronic Noses
(electrochemical
sensors)
10-100 Parts
per billion
Measures multiple chemical
constituents that are known
to be odiferous
May not be able to detect all
the compounds emitted by
source known to be part of the
odor profile. Limited to specific
parameters and sensor types.
Total Reduced
Sulfurs (TRS)
Parts per billion Proven real-time surrogate
for odor concentration
Only works in high odor load
areas. Capability is severely
diminished outdoors.
Analytical Lab Analysis
There are a limited number of accepted standardized analytical methods performed by accredited laboratories for some compounds that are known to be odiferous. These methods include sample collection procedures, sample handling, as well as analytical methods specific to compounds or classes of compounds. Sulfonated compounds using ASTM D-5524 and certain Volatile Organic Compounds (VOCs) using EPA T0-15 are examples. With these methods, each sample can be tested for multiple compounds and down to a relatively low detection limit. This is important as many odiferous compounds have very low odor detection thresholds. It’s important that the sample collection and analytical method are compatible with the odor detection threshold of the target compound(s). However, each sample is only representative of a snapshot in time, and doesn’t show real-time or immediate results. Conducting the field sampling requires training, and each individual sample has an associated cost.
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Photoionization Detectors (PID)
PIDs are field measurement tools that detect VOCs. They produce real-time readings and are generally used during first responses for many use cases, such as detecting a potential leak in the system or qualitative assessment of the presence of VOCs. However, while they are fast responding and can detect multiple VOCs, they cannot speciate and differentiate the compounds detected from each other. This may be ineffective in cases where there are multiple background compounds present.
Portable Gas Chromatograph (GC)
Portable Gas Chromatographs (GC) can be deployed in the field to speciate VOCs. However, while this method can identify and quantify individual VOCs, there are limitations to this method. GCs can only quantify predetermined, thermally stable compounds. Compounds with similar retention times can also be measured which leads to co-elution and potential interferents. Additionally, the VOCs identified may or may not be contributors to the odor profile. This method may not be real-time, but readings can be generated in field, and samples can be collected and analyzed roughly every 10 minutes. This method provides a middle ground between real-time sampling and discrete grab samples.
Electronic Nose
The Electronic Nose (e-Nose), is a type of electrochemical device that uses sensors that generate signal patterns to characterize odors. These sensors detect and react to different molecules which create response patterns due to changes in electrical properties that are then interpreted and analyzed. Most e-Noses use chemical sensor arrays that react to volatile compounds on contact, and the adsorption of these compounds causes a physical change of the sensor, which is then translated by the electronic interface into a digital value. E-Noses have been used in evaluation of odors related to the food, health, drug, safety, crime, and the environmental and agricultural sectors. However, it should be noted that they do not measure odors directly and that this technology uses chemical surrogates to calculate an odor index. The value an e-Nose can provide is limited to the array of sensors installed and may not correlate well with cannabis emission sources.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com
Section 5.2 Summary and Recommendations
• We recommend responsibility for odor source identification and monitoring fall to cannabis operators and their qualified third-party consultants, subject to City oversight. • We recommend facilities engaged in cultivation, manufacturing, or processing install and maintain onsite MET sensors to record wind direction and speed. • We recommend facilities maintain detailed records for identified odor sources. • We recommend the City reserve authority to require air sampling, emissions rate monitoring, or dispersion modeling where field inspections are inconclusive or disputed. • We recommend a tiered response system for verified odor events, with escalating actions based on severity, complaint volume, and facility history, aligned with Section 5.0 recommendations.
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BIBLIOGRAPHY
A. B. Malnic et al, Cell, 1999, 96, 713
American Industrial Hygiene Association, 2013. Odor Thresholds for Chemicals with Established Health Standards, Second Edition, Falls Church, Virginia: s.n.
Autelitano, F. a. G. F., 2018. Anatical assessment of asphalt odor patterns in hot mix asphalt production. Jornal of Cleaner Production, Volume 172, pp. 1212-1223.
Freemantle, M., 1999. Chemical & Engineering News. [En ligne] Available at: cen.acs.org
Grahn, K. G. P. A. T. L. A. H. T. S. J. a. P. W., 2021. Occupational exposure to particles and increased risk of developing chrominc obstructive pulmonary disease (COPD). A population-based cohort study in Stockholm, Sweden. Environmental Research 200: , p. Article 111739.
Hansen, E., 1991. Mortality of mastic asphalt workers. Scandinavian Journal of Work and Environmental Health 17, pp. 20-24.
IARC, 2013. Bitumens and Bitumen Emissions, and Some N- and S- Heterocyclic Polycyclic Aromatic Hydrocarbons. Volume 103. Lyon, France: s.n.
Jue Li, Y. Q. X. B. S. a. C. L., 2024. Emission Characeristics, Environmental Impacts and Health Rsisks of Volatile Organic Compounds from Asphalt Materials: A State-of-the-Art Review. Energy & Fuels .
Kargar-Shouroki, F. M. M. S. M. S. S. F. M., 2021. Genotoxic effect of exposure to polycyclinc aromatic hydrocarbons (PAHs) in asphalt workers. EXCLI Journal 20, pp. 686-697.
Lange, C. a. M. S.-G., 2005. Quantification of Potentially Odorous Volatile Organic Compounds from Asphalt Binders Using Head-Space Gas Chromatography. ASTM Journal of Testing and Evaluation, March, 33(2), pp. 101-109.
M. Edwards, J. H. R. H., 2020. Odour Management Guidance for Refineries, Brussels: CONCAWE.
NIOSH, 2024. NIOSH Pocket Guide to Chemical Hazards.. [En ligne].
OSHA, 2024. OSHA Occupational Chemical Database. [En ligne] Available at: https://www.osha.gov/chemicaldata/710
Petronaft, 2024. htttps:www.petronaftco.com/oxidized-bitumen. [En ligne].
Wikipedia, 2024. Heterocyclic Compound. [En ligne].
World Health Organization, 2004. Concise International Chemical Assessment Document 59. Aspahlt (Bitumen), Geneva: s.n.
Z. Zhou and L. B. Buck, Science, 2006, 311, 1477
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com Page A
Appendix A
What is Odor?
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com Appendix Page A-1
What is Odor?
Odor is a perception and is dependent not only on the relative chemistry and structure of odor molecules, but also on receptor factors such as sex, age, culture, social context, and personal experience. Odor perception is complex as responses to odors are inherently subjective and the nature and composition of odorants can vary greatly. In addition, different societies have varying levels of acceptance for odors in their communities.
Olfactory System
People can discriminate more than 10,000 odors, even though there are only about 400 odor receptors in the nose (Coker, 2013). An odor can generally be perceived if several criteria are met (Govind, 2023).
• There is an odor generating source present,
• The odorant molecule(s) is a volatile compound (VC),
• The odorant’s molecular weight is less than 300 Daltons, • The odorant’s vapor pressure is greater than 0.01 kilopascals (kPA) at 20 °C, and • The odor molecule has moderate-to-high hydrophobicity.
During the respiratory process, when odorous molecules enter the nasal canal, they reach the olfactory epithelium, near the top of each nostril. At this point, the molecules dissolve in the mucus layer covering the epithelium and contact olfactory sensory neurons (millions) which express the odor receptor(s) (~400) (Alila Medical Media, 2021). The combination of activated neurons and odor receptors send signals to the olfactory bulb, where the signal is deciphered and subsequently perceived by the brain as an odor perception. When you have a cold, your sense of smell is diminished because molecules have a harder time reaching the odor receptors. See Figure 1.
Studies on the interactions between
individual odor receptors and multiple
chemical odorants found that:
• An odor receptor can recognize many
odorant molecules, and
• An odorant molecule can bind to and
be detected by multiple odor
receptors.
Through the use of approximately 400
odor receptors in humans, the brain can
differentiate between a large number of
odorants simultaneously. Thus, although
there are only a few hundred active odor
receptors, humans can recognize over
10,000 different odors. This method is
referred to as the “Receptor Code”. The
receptor code is essentially the unique
pattern of activated receptors for a
specific odorant, and this pattern can shift
depending on concentration, leading to different odor perceptions.
Figure -1: Human Olfactometry System (Coker, 2013)
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com Appendix Page A-2
Chemical Concentration and Mixture Effects
Researchers have found that changes in odorant concentration alter its receptor code in the olfactory system. This explains why, for some chemicals, a substance smells different at different concentrations. As the concentration of an odorant increases, the set of olfactory receptors activated also changes, leading to a different perception of the smell, even for the same odorant molecule.
Additionally, research has shown that some neurons in the olfactory cortex only respond when two odorants are present and not when each component is present on its own, explaining why mixtures can have smells that are not simply the sum of the component molecules (Z. Zhou and L. B.
Buck, Science, 2006, 311, 1477).
Odor Assessment
The relative detectability of odor is a sensory property that refers to the theoretical minimum concentration that incites an olfactory response or sensation. This point is called the odor detection threshold, often referred to through the dilution to threshold ratio (D/T) and defines one odor unit (1 OU). Based on the available literature, the level at which odors are perceived to be a nuisance can range from 2 OU to 10 OU depending on the following variables or factors:
• Odor Quality: odor results stemming from a pure compound tend to have a higher threshold (less offensive) than a mixture of compounds.
• Odor Frequency, Timing, and Duration: when and how an odor is perceived within a community affects the annoyance and offensiveness of the odor. • Population Sensitivity: individuals have a range of sensitivity to odors. This is affected by past experiences and previous exposures as well as individual association with the odor. Some of the population may find certain odors pleasant, which can be found offensive to other members of the population. This factor appears to be especially true relative to cannabis odor.
• Background Level: background odors can affect the degree to which a specific source contributes to a cumulative impact. Due to the saturation density of cannabis cultivation in certain instances this is an important consideration.
• Public Expectation: the relative level of community tolerance to an odor. For example, farming communities may consider a background level of odor to not be offensive even at high concentrations while residents of other communities find the same odors offensive even at low concentrations.
• Source Characteristic: how the odors are emitted is an important factor. Controlling odors from a point source is significantly easier to control than odors from an area or diffusive source.
Odor Detection Threshold
The odor detection threshold (ODT) is the lowest concentration of an odorant that can be detected by a person. The concentration is established through testing conducted on human subjects in a laboratory setting and is commonly listed as the lowest concentration at which at least 50% of test subjects perceive an odor. The lower the detection threshold, the more potent the odor is. For example, hydrogen sulfide (characterized by a rotten egg odor) can be detected at a concentration as low as 0.0005 part per million by volume (ppmv) while carbon dioxide (vegetable, sulfide, medicinal odor) is not detected until a concentration over 39,000 ppmv.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com Appendix Page A-3
Because sensitivity to odor is subjective and varies from person to person, detection thresholds established for compounds vary and for this reason are frequently listed as a range of concentrations.
Due to the logistical constraints of using certified odor panels, it is not feasible to use odor panel analysis for complaint response. This is because odor panels need to be reserved ahead of time.
Any ordinance that specifies an ambient odor threshold (D/T, DT, RT, "Odor Units", etc.) should also specify the method of measurement as the different measurement methods produce different results. In addition, the effect of background odor concentrations on these measurements needs to be considered, as do the meteorological conditions during an odor event.
Due to the factors above SCS recommends that a Nasal Ranger or similar device be used for compliance monitoring relative to odors. In addition, the following factors should be considered:
1) Assessments of a source’s contribution to downwind odors should include measurements of background and or upwind odor and the differential in the two measurements should be considered as the net increase in odor.
2) SCS recommends a 7 D/T increase as a benchmark for downwind odor impacts if using detection threshold (DT).
3) SCS recommends a 4 D/T increase as a benchmark for downwind odor impacts if using recognition threshold (RT).
Finally, the ordinance should specify the number of observations that need to be made by the inspector and the period from which the observations need to be made. SCS recommends the average of 3 observations collected 5 minutes apart. This will confirm persistent conditions while not implicating sources if only a fleeting odor is detected.
Odor Characterization
Concentration alone does not describe the entire human response to an odor. Various qualitative and quantitative parameters are used to illustrate human perception to odors. A summary of parameters that can be used to further describe odor is provided in Table 1.
Table A-1: Technical parameter definitions used for describing odors Parameter Description
Concentration Odor concentration is quantified by determining the amount of dilution required to bring the odorous air sample to a detection threshold.
Intensity Odor intensity refers to the perceived strength of the odor. A quantitative measurement of intensity requires comparison of the odor to a “standard,” typically n-butanol in odor-free air. The intensity is expressed in terms of micrograms per cubic meter of n-butanol and is related to concentration through a power function.
A qualitative scale can also be used to describe intensity with zero being not perceptible to 6 being extremely strong.
Character Odor character describes what the substance smells like.
Examples of odor character include fishy, hay, nutty, oily, creosote, turpentine, rancid, sewer, sweet, ammonia, skunky, pine, wet grass, burnt hair, etc.
Hedonic Tone
(Offensiveness)
Hedonic tone is a subjective judgment on the relative pleasantness or unpleasantness of an odor.
Hedonic tone can be assessed on a graded scale from -4 (extremely unpleasant) to +4 (extremely pleasant) and 0 being neutral (neither pleasant or unpleasant)
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com Appendix Page A-4
Cannabis Specific Odor Drivers and Variables
The understanding of the primary cause of the odor, particularly the disagreeable "skunky" odor emitted from cannabis cultivation, and the methods to mitigate it, are rapidly evolving. Just a few years ago, it was a common perception that the main culprit relative to odors from cannabis operations were terpenes. We now know that although terpenes are part of the odor profile, they are not the cause of the unpleasant “skunky” odor character often experienced downwind from cannabis operations. Terpenes are not the main driver of odor concentration downwind from cannabis facilities.
There is interest by several entities to establish an odor detection threshold relative to cannabis odor emission. The idea is to have a molecule or class of molecules, operate as a surrogate for expected odor concentration and thus be used to determine a threshold for which objectionable odors are likely to be perceived by humans. Several factors complicate this consideration:
1) Cannabis, like most plants, has the potential to emit hundreds of different chemicals. Each at various rates, at widely divergent odor detection thresholds, and dependent on several external variables;
2) Emission rates are not constant throughout the cannabis plant life cycle or within the plant’s diurnal cycle;
3) Emission rates are influenced by temperature, exposure to light radiation, degree of agitation, and plant stresses, among other external factors. 4) The ratios of compounds emitted by cannabis are not constant through the plant’s life cycle and the times of highest emission of certain compounds can be decoupled from the emission of other types of compounds.
5) Relative strains of cannabis have different chemical ratios and thus varying odor profiles.
Identifications of Odorous Compounds Emitted by Cannabis When SCS began working with cannabis growers, we were already well-versed in odor investigations relative to landfills, recycling centers, compost facilities, and water treatment plants. SCS was familiar with identifying a facility’s “odor footprint” through the use of ASTM-defined olfactory assessment using odor panels in combination with flux measurements from the sources at these facilities. In addition, the main culprit for objectionable offsite odors is almost always Hydrogen Sulfide (H2S) for these types of facilities and sources. The nature and understanding of these sources have been studied for decades. There is ample understanding of how odor emissions are generated and presently there are significantly researched methods to mitigate odor from these types of sources and facilities, which are more straightforward than for cannabis cultivation.
Initial Tests of Cannabis Emissions
Most analytical labs in the United States are set up to perform standardized test methods for known criteria pollutants or hazardous air pollutants (HAPs). In addition, the common public understanding was that the main source of odors was associated with the terpenoid class of compounds. There was also interest in determining whether cannabis emissions result in concentrations of HAPs that could be a potential health concern. Therefore, initially, SCS focused on Volatile Organic Compounds (VOCs) and terpenoids using standardized methods.
SCS utilized EPA Method TO-15 to assess the concentrations of VOCs that are also considered Hazardous Air Pollutants. SCS also requested tentative identification of a large list of other compounds for which the laboratory doesn’t carry standards but can be identified through chromatography and detection. SCS used non-standardized methods developed by the Desert Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com Appendix Page A-5
Research Institute (DRI) to identify and quantify concentrations of a large library of terpenoids. Tests were performed in all aspects of cannabis operations including greenhouses, processing areas, drying rooms, and nurseries.
All of the tests showed that concentrations of VOCs and terpenoids were either not detectable or significantly below published health standards regardless of the location of the samples. In addition, the tests identified three terpenes that were present in almost every sample collected relative to a cannabis source. These terpenes were identified as Myrcene, Pinene, and Limonene. Caryophylene and Linalool were also detected in most samples. Tests indicated that emissions from the drying and curing phases of cannabis production were significantly higher than during the cultivation stage.
However, there were significant limitations to these tests:
1. The tests provided data that represented only the period and location from which the samples were collected.
2. The odor character of the measured terpenes does not represent the objectionable “skunky” character attributed to odor issues.
3. The tests were limited to Volatile Organic Carbons and terpenes. Other classes of compounds were not measured.
Identification of Volatile Sulfonated Compound (VSC) Emissions In SCS’s early investigations of cannabis emissions, we speculated that a sulfonated compound or a class of sulfonated compounds was the likely cause of the “skunky” character observed in the vicinity of cannabis operations. To test this theory, SCS performed an experiment.
The experiment entailed the collection of a ½ ounce of wet mature flower from 8 different strains of cannabis collected from multiple farms. SCS fabricated a blender/food processor with a bulkhead fitting at the top for the collection of a headspace sample. SCS then chopped/mixed each flower in the blender individually for 30 seconds. Immediately following the blending, SCS collected a headspace sample from above the blended cannabis. Immediately following sample collection, SCS delivered the samples to Atmospheric Analysis & Consulting, Inc. for analysis via ASTM-D5504. This method analyzes 21 different sulfonated compounds as well as Total Reduced Sulfurs (TRS). The difference between the sum of the detected sulfonated compounds and the TRS indicates the presence of an unidentified sulfur compound. The results of this test confirmed the hypothesis that VSCs were present for multiple strains. Three specific VSCs were identified, Carbonyl Sulfide, Dimethyl Sulfide, and Methyl Mercaptan. In addition, total reduced sulfur was detected in 6 of the 8 strains. The strains that were identified with the largest concentrations of total reduced sulfur were also confirmed to be the “skunkiest” strains based on the observations of cultivators.
Since this time, studies from other cannabis researchers have confirmed the presence of additional VSCs as potential sources of malodors from cannabis. To date, the following VSCs have been identified along with their relative scent character:
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com Appendix Page A-6
VSC Odor Character
• Dimethyl Sulfide: Sulfurous, cabbage
• Carbonyl Sulfide: Sulfurous, cabbage
• Methyl Mercaptan: Rotten cabbage
• 3-Methylthiophene: Fatty, wine-like
• 3-Methyl-2-butene-1-thiol: Intense, sulfurous, skunk-like • 3-methyl-1-(methylthio)-2-butene: Intense, sulfurous, savory • 3-methyl-2-butenyl acetothioate: Intense, sulfurous, skunk-like • bis(3-methyl-2-butenyl) sulfide: Mild, Onion and/or Garlic • bis(3-methyl-2-butenyl) disulfide: Mild, Onion and/or Garlic
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com Page B
Appendix B
Example Forms
Facility Name & Location
Primary Odor Contact at Facility
Date / Time Complaint Receieved
Complaintant Information
Name
Contact Number
Email
Location of Odor Detected
Odor Type
Strength of Odor (1-10 Scale | 1 = no smell, 10 = overwhelming odor) Odor Direction (What direction was the odor observed to be coming from) Was weather unusual during odor detection event?
Odor character description
Site Conditions & Specifics Related to Odor Complaint
Wind Direction at time (Use MET Data)
Barometric Pressure
Action Taken
Action Taken (Consult Tiered Response)
NOTES:
Person Conducting the Inspection:
Date of Inspection:
Time of Observation :
Wind Direction (at the surveyor's location): N; NE; E; SE; S; SW; W; NW Barometric Pressure:
Measured in HG as recorded at the onsite weather station Intesity:
(S
‐
Strong; M
‐
Medium; Sl
‐
Slight)
Odor Complaint Response Form
Online Odor Complaint Form
Submitting Your Complaint
COMPANY provides several ways of submitting an odor complaint in the community. Feel free to use any of the listed complaint system methods to provide us your submission.
Thank you and we look forward to hearing from you.
Web Form: complete and submit the interactive form on this page Call:
Text:
Email:
Disclaimer: Information given through our complaint management system will be used solely by COMPANY. Your name and address is secured and no information will be given or sold to any third party.
Title
User Information
First Name
Last Name
Contact
Home Phone
Address
Cell Phone
Apt/Suite #
City
State
Zipcode
Remember my details on this computer for next time
(Not recommended if on a public or shared device)
Contact Preferences
I would like to speak with someone as soon as possible
I am happy to discuss this complaint should there be questions I would like a copy of this complaint sent to my email
Please do not contact me regarding this complaint
Save and Enter Odor Details
Odor Details
We kindly ask that you provide as much information as possible. Details will help us review and process your submission.
Date
Time
Odor Detection Location
Where did you notice the odor?
Please identity the approximate location where you noticed the odor. (NOT where you think it is coming from)
Click on the map to drop a pin.
This will populate the LAT and LON automatically.
Online Odor Complaint Form
Use my address from the previous user information section Save and Enter Odor Details
Odor Intensity
Very Faint
Faint
Distinct
Strong
Very Strong
Addition Comment
Please add any additional comments pertaining to your concerns. (Ex. Smells like a sunk or sewage. Smell lasted for several hours.) Odor Description
Ammonia
Burn/Smoke
Sewer/Sewage-like
Chemical/Solvent
Earthy/Moldy/Musty
Fishy
Manure
Decaying Grass
Rotten Egg
Turpentine
Woody
Other – See Notes
(enter notes)
(enter notes)
Save and Submit Odor Complaint
Online Odor Complaint Form
Cultivation Facility Audit Checklist
INSPECTION ITEM Y N NA NOTES
1. Direct Observation
a. At Property Line ☐ ☐ Intensity:
b. Adjacent to facility structure ☐ ☐ ☐ Intensity:
2. State and local cultivation license
valid ☐ ☐
3. Odor Management Plan (OMP)
a. OMP date:
b. Located onsite ☐ ☐ ☐
c. Up to date ☐ ☐ ☐
d. Employee training record for
odor mitigation procedures
reviewed
☐ ☐ ☐
4. Facility diagram reviewed ☐ ☐ ☐
a. Odor control system located
on map ☐ ☐ ☐
b. Exhaust points located on
map ☐ ☐ ☐
c. Negative pressure system
labeled on map ☐ ☐ ☐
d. ___________ located on map ☐ ☐ ☐
5. Approved odor control system ☐ ☐ ☐ Make/Model:
a. Installed and operational ☐ ☐ ☐
b. Routine inspection
documented (+ take photos) ☐ ☐ ☐ Inspection frequency:
c. Filters clean ☐ ☐ ☐ Replacement frequency:
6. Air filtration units
a. Operational ☐ ☐ ☐
b. Labeled on facility diagram ☐ ☐ ☐
c. Maintenance log reviewed ☐ ☐ ☐ Last maintenance date:
d. Filters clean ☐ ☐ ☐ Replacement frequency:
7. Ventilation system
a. Operational ☐ ☐ ☐
b. Labeled on facility diagram ☐ ☐ ☐
c. Visible signs of buildup in
ducts or on vents ☐ ☐ ☐
d. Integrated with odor control
system ☐ ☐ ☐
e. Diagrams reviewed ☐ ☐ ☐
f. Maintenance log reviewed ☐ ☐ ☐ Last maintenance date:
8. Negative pressure system ☐ ☐ ☐
a. Operational ☐ ☐ ☐
INSPECTION ITEM Y N NA NOTES
b. Documented on facility
diagram ☐ ☐ ☐
9. Cultivation areas ☐ ☐ ☐
a. Enclosed ☐ ☐ ☐
b. Properly sealed ☐ ☐ ☐
c. Floor is clean; product is not
tracked everywhere ☐ ☐ ☐
10. Waste areas ☐ ☐ ☐
a. Enclosed ☐ ☐ ☐
b. Properly sealed ☐ ☐ ☐
c. Cannabis odors observed ☐ ☐ ☐
11. Facility operated odor complaint
management system
a. Available and operational ☐ ☐ ☐
b. Documented responses
accessible ☐ ☐ ☐ Review frequency:
12. Building envelope
a. Doors close automatically ☐ ☐ ☐
b. Operable windows in odor-
prone areas closed ☐ ☐ ☐
c. Air leaks and sources visible ☐ ☐ ☐
d. Loading/Unloading areas
enclosed ☐ ☐ ☐
Inspection Notes:
6d – clean filters are not loaded with a layer of dust or other materials. Dust or other materials may be on the filter but the filter itself is visible through the loading. Filters should be spot checked at easily accessible locations. Inquire about the pr ocess of how operators change filters.
Distribution Facility Audit Checklist
INSPECTION ITEM Y N NA NOTES
1. Direct Observation
a. At Property Line or adjacent
to facility ☐ ☐ Intensity:
b. Office space – Odors observed ☐ ☐ ☐ Intensity:
2. State and local cultivation license
valid ☐ ☐
3. Odor Management Plan (OMP)
a. OMP date:
b. Located onsite ☐ ☐ ☐
c. Up to date ☐ ☐ ☐
d. Employee training record for
odor mitigation procedures
reviewed
☐ ☐ ☐
4. Facility diagram reviewed ☐ ☐ ☐
a. Odor control system located
on map ☐ ☐ ☐
b. Exhaust points located on
map ☐ ☐ ☐
c. Negative pressure system
labeled on map ☐ ☐ ☐
d. Click or tap here to enter
text. located on map ☐ ☐ ☐
5. Approved odor control system ☐ ☐ ☐ Make/Model:
a. Installed and operational ☐ ☐ ☐
b. Routine inspection
documented (+ take photos) ☐ ☐ ☐ Inspection frequency:
c. Filters clean ☐ ☐ ☐ Replacement frequency:
6. Waste areas ☐ ☐ ☐
a. Enclosed ☐ ☐ ☐
b. Properly sealed ☐ ☐ ☐
c. Cannabis odors observed ☐ ☐ ☐
7. Facility operated odor complaint
management system
a. Available and operational ☐ ☐ ☐
b. Documented responses
accessible ☐ ☐ ☐ Review frequency:
8. Building envelope
a. Doors close automatically ☐ ☐ ☐
b. Operable windows in odor-
prone areas closed ☐ ☐ ☐
c. Air leaks and sources visible ☐ ☐ ☐
d. Loading/Unloading areas
enclosed
☐ ☐ ☐
Manufacturing Facility Audit Checklist
INSPECTION ITEM Y N NA NOTES
1. Direct Observation
a. At Property Line or adjacent
to facility ☐ ☐ Intensity:
b. Office space – Odors observed ☐ ☐ ☐ Intensity:
2. State and local cultivation license
valid ☐ ☐
3. Odor Management Plan (OMP)
a. OMP date:
b. Located onsite ☐ ☐ ☐
c. Up to date ☐ ☐ ☐
d. Employee training record for
odor mitigation procedures
reviewed
☐ ☐ ☐
4. Facility diagram reviewed ☐ ☐ ☐
a. Odor control system located
on map ☐ ☐ ☐
b. Exhaust points located on
map ☐ ☐ ☐
c. Negative pressure system
labeled on map ☐ ☐ ☐
d. ___________ located on map ☐ ☐ ☐
5. Cannabis Processing Onsite ☐ ☐ ☐
a. Flower Cannabis Processing ☐ ☐ ☐
b. Extract processing ☐ ☐ ☐
6. Approved odor control system ☐ ☐ ☐ Make/Model:
a. Installed and operational ☐ ☐ ☐
b. Routine inspection
documented (+ take photos) ☐ ☐ ☐ Inspection frequency:
c. Filters clean ☐ ☐ ☐ Replacement frequency:
7. Air filtration units
a. Operational ☐ ☐ ☐
b. Labeled on facility diagram ☐ ☐ ☐
c. Maintenance log reviewed ☐ ☐ ☐ Last maintenance date:
d. Filters clean ☐ ☐ ☐ Replacement frequency:
8. Waste areas ☐ ☐ ☐
a. Enclosed ☐ ☐ ☐
b. Properly sealed ☐ ☐ ☐
c. Cannabis odors observed ☐ ☐ ☐
9. Facility operated odor complaint
management system
a. Available and operational ☐ ☐ ☐
INSPECTION ITEM Y N NA NOTES
b. Documented responses
accessible ☐ ☐ ☐ Review frequency:
10. Building envelope
a. Doors close automatically ☐ ☐ ☐
b. Operable windows in odor-
prone areas closed ☐ ☐ ☐
c. Air leaks and sources visible ☐ ☐ ☐
d. Loading/Unloading areas
enclosed ☐ ☐ ☐
11. Storage area ☐ ☐ ☐
a. Product is stored in odor-proof
packaging ☐ ☐ ☐
b. Packages ready to ship – Odors
observed ☐ ☐ ☐
Consumption Lounge Audit Checklist
INSPECTION ITEM Y N NA NOTES
1. Direct Observation
a. At Property Line or adjacent
to facility ☐ ☐ Intensity:
b. Office space – Odors observed ☐ ☐ ☐ Intensity:
2. State & local cultivation license
valid ☐ ☐
3. Odor Management Plan (OMP)
a. OMP date:
b. Located onsite ☐ ☐ ☐
c. Up to date ☐ ☐ ☐
d. Employee training record for
odor mitigation procedures
reviewed
☐ ☐ ☐
4. Facility diagram reviewed ☐ ☐ ☐
a. Odor control system located
on map ☐ ☐ ☐
b. Exhaust points located on
map ☐ ☐ ☐
c. Negative pressure system
labeled on map ☐ ☐ ☐
d. ___________ located on map ☐ ☐ ☐
5. Approved odor control system ☐ ☐ ☐ Make/Model:
a. Installed and operational ☐ ☐ ☐
b. Routine inspection
documented (+ take photos) ☐ ☐ ☐ Inspection frequency:
c. Filters clean ☐ ☐ ☐ Replacement frequency:
6. Air filtration units
a. Operational ☐ ☐ ☐
b. Labeled on facility diagram ☐ ☐ ☐
c. Maintenance log reviewed ☐ ☐ ☐ Last maintenance date:
d. Filters clean ☐ ☐ ☐ Replacement frequency:
7. Ventilation system
a. Operational ☐ ☐ ☐
b. Labeled on facility diagram ☐ ☐ ☐
c. Visible signs of buildup in
ducts or on vents ☐ ☐ ☐
d. Integrated with odor control
system ☐ ☐ ☐
e. Diagrams reviewed ☐ ☐ ☐
f. Maintenance log reviewed ☐ ☐ ☐ Last maintenance date:
8. Negative pressure system ☐ ☐ ☐
a. Operational
☒
☐ ☐
INSPECTION ITEM Y N NA NOTES
b. Documented on facility
diagram/plans ☐ ☐ ☐
9. Waste areas ☐ ☐ ☐
a. Enclosed ☐ ☐ ☐
b. Properly sealed ☐ ☐ ☐
c. Cannabis odors observed ☐ ☐ ☐
10. Facility operated odor complaint
management system
a. Available and operational ☐ ☐ ☐
b. Documented responses
accessible ☐ ☐ ☐ Review frequency:
11. Building envelope
a. Doors close automatically ☐ ☐ ☐
b. Operable windows in odor-
prone areas closed ☐ ☐ ☐
c. Air leaks and sources visible ☐ ☐ ☐
d. Loading/Unloading areas
enclosed ☐ ☐ ☐
12. Storage area ☐ ☐ ☐
a. Product is stored in odor-proof
packaging ☐ ☐ ☐
b. Receiving area – Odors
observed ☐ ☐ ☐
Retail Facility Audit Checklist
INSPECTION ITEM Y N NA NOTES
1. Direct Observation
a. At Property Line or adjacent
to facility ☐ ☐ Intensity:
b. Indoor – Odors observed ☐ ☐ Intensity:
c. Office space – Odors observed
2. State and local cultivation license
valid ☐ ☐
3. Odor Management Plan (OMP)
a. OMP date:
b. Located onsite ☐ ☐ ☐
c. Up to date ☐ ☐ ☐
d. Employee training record for
odor mitigation procedures
reviewed
☐ ☐ ☐
4. Facility diagram reviewed ☐ ☐ ☐
a. Odor control system located
on map ☐ ☐ ☐
b. Exhaust points located on
map ☐ ☐ ☐
c. Negative pressure system
labeled on map ☐ ☐ ☐
d. ___________ located on map ☐ ☐ ☐
5. Air filtration units
a. Operational ☐ ☐ ☐
b. Labeled on facility diagram ☐ ☐ ☐
c. Maintenance log reviewed ☐ ☐ ☐ Last maintenance date:
d. Filters clean ☐ ☐ ☐ Replacement frequency:
6. Storage area ☐ ☐ ☐
a. Receiving area – Odors
observed ☐ ☐ ☐
b. Displays are filtered and
vented ☐ ☐ ☐
CITY OF CATHEDRAL CITY
RESPONSE TO CORRECTIVE ACTION NOTICE
PLAN OF ACTION
Company Contact
Address Cell
CORRECTIVE ACTION NOTIFICATION INFORMATION
Date of Inspection
Date of CAN By Whom
Plan of Action Due Date By Whom
Mitigation Due Date By Whom
Equipment and
Parameters
Breakdown
Description
Breakdown
Cause
Corrective
measures taken
to avoid future
occurrences.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com Page C
Appendix C
Communication and Public Outreach
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com Appendix Page C-1
Communication and Public Outreach
It is important to realize that a community relations program will not solve your odor issues. But be assured that you will not resolve them successfully without a community outreach program. Having good lines of communication with your neighbors will greatly enhance your success to isolate any causes of odor impacts and guide the design to ultimately control impacts. Community outreach serves not only to educate the public about your facility, but it must establish a partnership between the facility operators and members of the public to work together to resolve issues. An antagonistic relationship will not help find reasonable and effective solutions.
The facility relationship with the community may not be limited to just odors issues. It may require expansion to collectively address a broad spectrum of potential environmental related neighbor concerns such as, but not limited to, traffic, noise, dust, and other environmental topics. When such a community relations program is enacted, the public will sense that they are involved with the entire operation and will help to foster public participation in the solution of any issues.
Understanding Community Concerns
When a person encounters an odor, particularly an offensive odor, their initial and primary concern is that the exposure to whatever is causing the odor will make them sick. This perception is evident not only for short term exposure (on the scale of minutes) but also for longer term exposures (days and months). In addition to health issues, people believe that when odor impacts occur, their property values will suffer. These concerns can drive community outrage and as outrage grows the sphere of influence of the odor impacts expand. Good communication with the public can reduce and even quell the outrage and enable the facility to reasonably deal with facts and not rumor or speculation.
When the public senses an offensive odor, they need to be able to voice their concern and have their questions resolved as quickly and honestly as possible. When people feel they have no recourse or means to resolve an issue, outrage and irrational thinking takes hold. It can be very difficult to gain the trust of the community when sentiments rise to this level or they have been misinformed. A good public relations program will provide easy pathways for the facility to respond to community issues as they occur. The bottom-line is that people need to be heard and taken seriously.
It is not uncommon for people to blame a facility for odors when that facility is not causing the odors.
People respond to impacts with what they see and sense and often do not rely on facts (for example is the wind blowing in a direction that would connect your facility with the person complaining?).
Alternatively, if real-time accurate information is conveyed from the community to the facility about detected odors, then effective and meaningful solutions can be tailored to mitigate impacts. Finally, the public wants to know that their welfare is being considered and prioritized in the operation of the facility.
Key Elements of Community Action Plan
Goal of your Community Outreach
The goal of a community outreach program is to establish a partnership with neighbors to the extent that you will work together to resolve problems. This involves building trust between the cannabis operator and the community. If this trust is lost, the facility is vulnerable to unreasonable and expensive mitigation imposed by regulatory authorities that are leveraged by a community that is not with the cannabis operator.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com Appendix Page C-2
Community outreach must entail the conveyance of regulatory compliance, open dialog of measured data and observations, meaningful and open discussion of problems, and review of tailored solutions of which the community feels that they were a significant contributor. A public relations program needs to make the community feel that they are nothing less than a valued partner in facility operation and compliance.
Engaging with Community
Connecting with the community needs to take on a comprehensive outreach effort that can reach all levels of the community. There is no common or primary way that people communicate and gain information, so it is encumbered upon the facility to reach out in a variety of ways. This includes, but not limited to, the following:
• Having a designated odor complaint point-of-contact at each cannabis facility, who is trained on understanding and observing odor events, able to receive and log complaints, as well as be knowledgeable on the facility’s odor control system, how it’s maintained, ensuring operationality conforming to the manufacturers recommendations, where system improvements are logged, and routinely evaluated. Maintenance logs should be stored onsite for at least 5 years and readily available for trend analysis and historical inquiry. • In person Town hall meetings and presentations – the more personal interaction the better the chances of building a relationship.
• Zoom or Teams meetings that people can attend via computer link • Focus group meetings with small numbers of people – perhaps people from individual block neighborhoods or logical segments or subsets of the overall community. • General Information and Policy meetings.
• Educational Seminars – each on specific topics concerning odors – teach people on how to evaluate odors.
• Summary status letters and flyers sent to the community backed up on social media. • Light social events within the community sponsored by the facility – get people together.
Conveyance of Regulatory Compliance
Compliance with regulatory conditions is very important. The facility operators need to convey to the community a vision of compliance. This needs to be done as simply as possible so the public understands what compliance means, including what information is used to assess compliance. It is important to share this data with the public in a way that is understandable and visual. If possible, illustrate how the community has helped in attaining compliance with regulatory issues.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com Page D
Appendix D
Cathedral City Council Staff Report: Cannabis Moratorium Update
Staff Report
City Council
Item No. 1.A
Meeting Date: April 23, 2025
From: Andrew Firestine, AICP, Director of Community and Economic Development
Title: Cannabis Moratorium Update
RECOMMENDATION:
This item is for discussion purposes to serve as an update on the cannabis moratorium. No action is requested.
BACKGROUND:
On February 26, 2025, the City Council extended the cannabis moratorium by 10 months and 15 days. Through the discussion, the City Council requested routine updates as staff conducts additional research and initiates updates to the City’s cannabis regulations and processes. The prior report focused on an evaluation of the City’s zoning, locational requirements, definitions, standards, and enforcement provisions, fines, and penalties while building out an odor control plan to implement the required conditions of approval. This report provides a synopsis of cannabis research conducted in other cities and counties and efforts to engage consultant support to set standards and to support the development of an odor control permitting process. It also provides updates on consultant support to the city specifically on C4 Industry and an odor control reporting and monitoring pilot program.
DISCUSSION:
Staff has commenced research in these areas, first by identifying all the California cities and counties that allow for cannabis cultivation in some manner, a list of 84 cities and counties, and conducted an initial review of the cannabis zoning regulations, licensing, and enforcement provisions for each of these cities and counties. This initial review was narrowed down to a smaller list of 15 cities and 3 counties that potentially offer insight into one or more of the areas of focus. A review of these city and county regulations, with an emphasis on zoning and enforcement, is summarized in the sections below with additional text contained in the attachments
Staff also initiated a records request through the Department of Cannabis Control (DCC) for the purpose of understanding how many large indoor cannabis cultivation facilities are licensed in the State of California. The DCC defines large indoor cannabis cultivation as those with more than 22,000 square feet of total canopy. For comparison, C4 Industry, the existing large cannabis cultivation facility near Date Palm Drive and Ramon Road has a gross floor area of 326,000 square feet and each of its 9 bays has a canopy area of 21,504 square feet together with an 8,760 square foot mother room, totaling over 200,000 square feet of total canopy area. While the DCC began accepting applications for large indoor cultivation licenses in 2020, there are only 6 other large indoor cultivation facilities licensed by the DCC, all of which are located in Richmond and Oakland. None of these are a good comparison to C4 Industry – most are substantially smaller in size and are older warehouses in industrial areas converted to cannabis cultivation.
The initial research of other city and county regulations, together with the additional information from the DCC, reveals that while there are some models for odor control permit processes and stronger enforcement, no city or county is at the forefront of cannabis regulation. No city or county has adopted objective cannabis odor standards and most rely on reactive and subjective odor measurements for enforcement. These preliminary findings raise the importance of the city’s existing condition of approval on cannabis conditional use permits requiring odor mitigation.
As was identified in previous staff reports, there is no separate plan or document and there are no standards or minimum requirements to demonstrate how the City’s odor mitigation requirements are to be met. Other cities and counties have established odor mitigation requirements through an odor control plan and permitting process, which is captured in the summary below. To ensure the City is setting the right standards, including the evaluation of technologies and the establishment of odor control requirements, the development of content and submittal requirements for an odor control plan, and the preparation of inspection checklists, consultant support is needed. To date, staff has met and engaged with five companies with significant experience in cannabis odor control and monitoring and has prepared a scope of work specific to the City’s needs. This scope of work was issued for informal bid on April 14 with bids requested by April 28. A summary of the expected scope of work is provided below.
Through the process of identifying prospective consultants to engage with on an update of the City’s cannabis regulations, staff identified a nationally recognized expert on soil vapor sampling, soil vapor analysis, and vapor intrusion for environmental and exploration applications who has extended his work into the cannabis industry through the monitoring of cannabis odor causing compounds by similar analysis. Dr. Blayne Hartman, with Hartman Environmental Geoscience, has analyzed cannabis odor control systems and offers the ability to provide the City a qualified opinion on the effectiveness of both the current and any additionally proposed odor mitigation at C4 Industry. The business remains responsible for designing, implementing, and maintaining their odor control solutions. Dr. Hartman’s work is to validate their effectiveness through an objective analysis and to make specific recommendations to the City. Dr. Hartman does not represent any equipment manufacturer and does not design cannabis odor control systems – he has no conflict of interest with C4 Industry or any other cannabis business operating in Cathedral City. Staff has negotiated a contract and scope of work with Dr. Hartman to evaluate the performance of the odor control systems at C4 Industry, both existing and proposed.
Finally, staff has also met with Envirosuite on several occasions. Envirosuite is a leader in environmental intelligence and offers a technology driven, real-time reporting and monitoring service that provides benefits to the City and to cannabis operators. C4 Industry has contracted with Envirosuite to implement a pilot program at their facility, a program that can potentially be expanded citywide. Under the pilot program, cannabis odor reports in the vicinity of C4 Industry would be reported through the Envirosuite platform embedded on the City’s website, collecting information on the location and strength and intensity of the odor.
Envirosuite’s monitors would also collect data on weather, volatile organic compounds (VOCs), and other compounds. All of this data would be made available to the City and the operator in real-time, which is intended to better correlate odor complaints with objective data, informing both City actions and operational changes at C4 Industry. Additional details on this pilot program and partnership are outlined below.
Cannabis Regulations
In its review of cannabis regulations from 15 cities and 3 counties, City staff evaluated seven zoning questions, including questions directed to odor mitigation and odor mitigation plans.
Staff further assessed four questions related to enforcement of odor violations. The complete data collected from this research is attached to the staff report. The zoning and enforcement research is summarized for Coachella, Palm Desert, Palm Springs, Desert Hot Springs, Oakland, and Richmond for each question below.
Zoning
1. What zoning districts are cannabis cultivation, manufacturing, and lab uses permitted?
Upon reviewing neighboring cities in the Coachella Valley such as Coachella, Palm Desert, Palm Springs, and Desert Hot Springs, as well as Oakland and Richmond, it is evident that cannabis uses such as cultivation, manufacturing, distribution, and testing labs uses are typically restricted to industrial zone districts, while dispensaries are permitted in both industrial and retail zones. Cultivation, manufacturing, distribution, and testing labs uses are generally not permitted within commercial or residential zones, reflecting a common zoning practice aimed at minimizing potential impacts on retail areas and neighborhoods.
2. What separation requirements existing between cannabis uses and either residential zones or uses and other sensitive uses? Identify both the use and the separation requirement.
The separation requirements from residential uses vary significantly. Under the California Business and Professions Code (BPC) Section 26054(b), cannabis businesses shall not be located within a 600-foot radius of a school providing K-12 instruction, a daycare center, or a youth center. Cities and counties, at a minimum, must implement this standard, although they may adopt more stringent standards, including other separation requirements.
As an illustration, Palm Springs established a 1,000-foot separation requirement between cannabis cultivation and manufacturing and a residential zoning district.
Coachella, Lancaster, and Pasadena each have a 600-foot separation requirement from commercial cannabis uses and residentially zoned property. Grover Beach requires a 100-foot setback between retailers and residential zones.
The other cities studied as part of this evaluation do not have an explicit separation from cannabis uses and residential zones or uses. Cathedral City is the only city evaluated that allows cultivation, manufacturing, and distribution in a commercial zoning district. The other cities limit those uses to industrial zones, which are generally separated from residential zones.
3. Are there separation requirements between cannabis uses? Palm Desert requires that cannabis retailers be 1,500 feet apart and similarly requires cannabis businesses within their service industrial zoning district to be separated by 1,500 feet. With some exceptions, Palm Springs requires cannabis businesses be separated by 500 feet. Among the other cities studied, Long Beach has a 1,000 foot separation requirement between dispensaries.
4. Are there limits on either the number or size of cannabis uses? A review of other city regulations shows that other cities place limits on the number of cannabis dispensaries allowed, often setting the cap between three and 10. In contrast, most do not impose limits on other types of cannabis operations, including cultivation, manufacturing, distribution, and testing laboratories. This reflects a regulatory trend aimed at controlling the retail presence of cannabis while allowing more flexibility for non-retail sectors of the industry. Santa Cruz and Moreno Valley are two cities that have additional requirements for cultivation facilities. Santa Cruz restricts indoor cultivation to a maximum of 10,000 square feet. Moreno Valley restricts the total area of the premises designated/used for the cultivation canopy to no more than 22,000 square feet, effectively prohibiting large indoor cultivation facilities, as defined by the DCC. Pasadena limits cultivation to four licensed facilities.
5. What is the definition of a nuisance cannabis odor?
Nuisance cannabis odor is not consistently defined across all city zoning codes.
However, some cities have established specific standards to address this issue. For example, the City of Palm Springs defines “Odor Detection Threshold” as the threshold for the detection of odorous contaminants when one volume of the odorous air has been diluted with seven or more volumes of odor free air as measured by any instrument, device, or any other method designated by the City.
Similarly, the City of Coachella defines "Odor Threshold Concentration" as the lowest concentration of Odorous matter that produces an olfactory response in normal human beings. Odor thresholds shall be determined in accordance with the American Society for Testing and Materials Test Method D1391-57 (reconfirmed to 1967) or in an equivalent manner acceptable to the zoning administrator.
These definitions require measurement through an olfactometer, such as the St.
Croix Sensory Nasal Ranger Field Olfactometer. The specialized device uses a combination of human nose and an instrument to detect and measure odors. While the definition has been adopted by some cities and counties, including Santa Barbara County most recently, it remains a subjective measurement and is not widely accepted as an effective way of detecting cannabis odor.
6. What are the odor mitigation requirements, either through a CUP or cannabis license? Are there specific requirements or standards for cultivation and manufacturing uses? Odor mitigation requirements are standard among the cities researched and are consistent with Cathedral City’s requirements that a business install odor absorbing ventilation and exhaust system so that odor generated inside the cannabis business are not detected outside. The systems include an exhaust air filtration system with odor control that prevents internal odors from being emitted externally; or an air system that creates negative air pressure between the interior and exterior so that the odors generated inside the cannabis business are not detectable outside.
7. Does the city or county require an odor mitigation plan or permit? If so, who is authorized to prepare and submit it? What are the submission requirements? Does it need to be renewed annually as part of the license? Who approves it? A common requirement found in the cities researched is the requirement to develop and implement a ventilation or odor control plan. These plans are required to include detailed information about the proposed ventilation system, including technical specifications indicating that the system can prevent the release of cannabis odors into the atmosphere from the cultivation or manufacturing operation. Coachella, Desert Hot Springs, and Palm Springs all require odor control plans. These are most often prepared by a licensed mechanical engineer. While Palm Springs requires an odor control plan to be prepared as part of a conditional use permit, other cities require it as a post-entitlement permit reviewed administratively and concurrent with a building permit. Some cities, including Palm Springs, use a third-party contractor to review odor control plans. Among the other cities, Grover Beach requires odor control systems to be certified annually.
Code Enforcement
8. What constitutes an odor violation? Are there thresholds or measurements for cannabis odor, either for the concentration of odor or the time period over which it is detected?
National City, La Mesa, and Desert Hot Springs require that odor not be detectable at the property line. El Dorado County uses the St. Croix Sensory Nasal Ranger Field Olfactometer, and Santa Barbara County established a nuisance threshold relying on an olfactometer as part of its recent cannabis code updates. Desert Hot Springs reported that it discontinued its use of the Nasal Ranger.
9. When there is an odor complaint, how is it investigated? Does the cannabis business have a period of time to correct a violation before a citation or further action is taken? If so, how long?
Several cities and counties require cannabis businesses to respond to cannabis odor complaints, including Santa Barbara County, Long Beach, and Desert Hot Springs.
Palm Springs allows cannabis businesses with a compliant odor control plan seven days to correct an odor issue.
10.What are the fines for a violation of the cannabis ordinance? Are there penalties beyond fines? If so, what?
Palm Springs has an escalating enforcement process. For odor violations related to a cannabis business with a compliant odor control plan, a cannabis business is first issued a written warning and given seven days to modify their odor control plan to mitigate odor issues. If the odor cannot be mitigated within seven days, the use must cease until effective odor control measures are in place. For odor violations with a non-compliant odor control plan, the business can be subject to a $10,000 administrative violation and have 30 days to remedy the odor issue and comply with their odor control plan before they’re issued another administrative citation of $10,000.
After three administrative citations, the permit shall automatically be revoked.
Desert Hot Springs code allows fines up to $1,000 per day, although their staff indicates that they have never needed to issue this fine.
11.Are there any unique provisions, such as a hearing officer, that warrant further evaluation?
Stanislaus County established a hearing officer process to conduct administrative hearings to determine whether the conditions described in the notice of violation, administrative citation and order to abate, and notice of hearing constitute a nuisance.
The hearing officer also considers the suspension, revocation, or non-renewal of cannabis permits.
Desert Hot Springs contracts with a third-party for all cannabis ordinance enforcement. Palm Springs contracts for the review of odor control plans.
Cannabis Consultant Support
On April 14, a scope of work for consultant support related to cannabis odor control was issued to four companies. This scope of work builds on the city and county research performed by City staff and seeks specific subject matter expertise on cannabis odor control.
It divides the work into six areas:
1. Regulatory review and best practices assessment
2. Odor control technology evaluation
3. Odor control permitting process
4. Inspection and verification protocols
5. Stakeholder engagement and presentations
6. Training
The full scope of work is attached for reference. It also included a timeline prepared by City staff leading to the presentation of an ordinance to the Cannabis Task Force and Planning Commission in August 2025 and the City Council in September 2025. Staff would be responsible for preparing the ordinance, but with input from the consultant to ensure the City is setting clear and appropriate standards and that the ordinance is accompanied by checklists and supporting documentation for any new processes.
In addition to this scope of work, a contract has been executed with Hartman Environmental Geoscience, the fifth consultant staff met with, specifically for the review of the odor control systems at C4 Industry, both existing and proposed. This contract allows up to 50 hours of consultant time and accounts for two site visits. Through the scope of work, they are tasked with providing the City a qualified opinion on the effectiveness of both the current and proposed odor mitigation plans and make specific recommendations to improve the effectiveness of the existing and any additionally proposed odor mitigation. This contract is not to support C4 Industry but rather to support the City in its review and assessment of the odor problem at C4 Industry using objective analysis and data.
Envirosuite
The City’s current process to report cannabis odors is inefficient and relies upon a platform that was not designed or intended for odor reporting. While it has been used to aggregate complaints, the information reported through the platform is not shared with a cannabis business in real-time. The auto-generated responses to a reporting party when a complaint is made are the same as any other code compliance case, which sets an expectation with the reporting party that the City will respond to their complaint individually. The volume of cannabis odor complaints has precluded staff from investigating and responding to each individual complaint. When the complaints are closed out by City staff, residents feel they are being ignored as the underlying issue has not been addressed. To address this, staff created an email distribution group that it has been sending weekly updates to both in response to cannabis odor complaints at C4 Industry and with respect to the cannabis moratorium.
Through the pilot program with Envirosuite, the City has an opportunity to substantially improve cannabis odor reporting for the area around C4 Industry. This could potentially be expanded to other areas of the City, but beginning in May 2025 an online form will be made available on the City’s website similar to what has been deployed in Des Moines, IA:
https://www.dsm.city/departments/neighborhood_services/odor.php.
The form will document the time and date of the complaint, location, description, and optional contact information for follow-up. Once submitted, City code compliance staff would be notified of a new complaint. Envirosuite would validate the plausibility of the complaint based on atmospheric conditions, including wind direction and speed, and the location of the complaint. Envirosuite also collects time-aligned sensor data and meteorological data. The sensors will be monitoring VOC, H 2S and NH 3 and can be programmed to monitor two additional compounds as may be directed by the City and its consultants.
Validated complaints are assigned to the business operator, in this case C4 Industry, for investigation and response. While the City does not presently have a response timeline for cannabis businesses to address odor complaints, the pilot program establishes an initial response time of 30 minutes during business hours and 90 minutes after hours, which would include an acknowledgement of the complaint, time of receipt, and immediate investigative steps. Under the pilot program, C4 Industry would be required to post a detailed investigation summary within 24 hours, including on-site observations, source identification (if any), and mitigation actions. Code compliance staff would be responsible for reviewing the investigation conducted by the business in response to a complaint, including its resolution.
The City’s role in the pilot program would be to support its implementation through the City website and to maintain oversight of it for the purpose of regulatory compliance, the tracking of complaints, and community engagement. The pilot program is proposed for a period of six-months, through which Envirosuite, C4 Industry, and the City will evaluate its effectiveness. The pilot program can be extended for an additional six-months upon mutual agreement.
Beyond its application in the area around C4 Industry, City staff are exploring the potential deployment of additional Envirosuite sensors and weather stations elsewhere in the City to permit cannabis odor reporting and monitoring through the Envirosuite platform. There is no estimated cost for these additional services at this point. They will be assessed and evaluated under the cannabis moratorium.
Next Steps
Staff anticipates that it will award a professional services contract to a cannabis consultant in the beginning of May and that staff and the consultant will immediately begin to identify those best practices the City should model in its updated cannabis regulations, including any new odor control requirements. The consultant is expected to produce an odor control permitting process for the City, including submittal and inspection checklists. While a substantial amount of work remains, staff has developed a timeline that would result in the presentation of an ordinance to the Cannabis Task Force and Planning Commission in August 2025 and City Council in September 2025.
FISCAL IMPACT:
The contract with Hartman Environmental Geoscience is not to exceed $12,500 and will be accommodated within the existing budget. The scope of work for the other consultant support was issued on April 14, 2025, for an informal bid with the expectation that it will be within the city manager’s signature authority. This contract is expected to be split between two fiscal years and will be accommodated within the existing and proposed budget.
FIVE-YEAR STRATEGIC PLAN:
F-17 – Review and update, as needed, our ordinances, policies, and practices regarding cannabis.
ATTACHMENTS:
1. City and County Cannabis Analysis
2. Cannabis Consultant Support Scope of Work
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com Page E
Appendix E
Odor Abatement Plan Template Checklists for Various Cannabis Facility Types
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com Appendix Page E-1
Cannabis Cultivation & Manufacturing (Processing)
Odor Abatement Plan (OAP) Checklist Template
1) Introduction and Source Identification
□ Operator Name
□ OAP Certifier/Author Details
□ Facility Name
□ Facility Address
□ APN(s)
□ Vicinity map with adjacent landuse / zoning with spatial distances between cannabis facility and proximal sensitive receptors
□ Facility floorplans with accurately dimensioned operational facility layout, and room use designations (e.g.: trimming room, cure room, greenhouses, nursery areas, cloning rooms, etc.)
□ Description of operations, any phased construction, details on existing operations and proposed operations, if differs
2) Description of Odor Emitting Activities or Processes □ Identification of odor emitting activities and processes □ Identification of odorants
□ Material Storage/Waste Generation
□ Operational/Production Schedules
□ Fugitive Sources
3) Description of Methods used for Odor Control
□ Active Odor Control System Design
• Odor control facility plan with odor control system callouts, including odor control system type, location of odor control devices, device quantity • Detailed description of proposed odor control devices, including location, quantity and system integration
□ Administrative Controls
• Daily site and system inspections
• Odor control system maintenance log
• Filter replacement schedule and log
• Housekeeping controls: keeping facility doors closed, use of air curtains at egresses, strip curtains at man doors and loading bays
□ Engineering Controls
• Odor control system design: e.g.: carbon filtration, multi-stage filtration, vapor phase, vegetative buffering and any other odor control systems to be implemented
• Ensuring proper air exchanges 3-4 per hour with odor control system/HVAC • Use of negative pressure to help facilitate odor control in sealed buildings • Description of all equipment and methods to be used for reducing odors • Inclusion of technical specifications and O&M materials provided by the odor control system manufacturer
• Example odor inspection logs, inspection checklists and example odor complaint response forms
□ Required Site Preparation
• Repairing paneling, installing vapor barriers, walls and ensuring building envelope is sealed, if retrofitting/tenant improvement an existing structure Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com Appendix Page E-2
there’s acknowledgement of repairing broken panels or closing gaps to ensure a tight sealed building envelope.
• Ensure existing/proposed electrical system can accommodate the proposed odor control system, some carbon scrubbers require substantial electrical loads. • Details on improvements to HVAC system to accommodate odor control systems • Cannabis processing areas are isolated from administrative areas • Entry areas with secondary door containment, and air filtering systems • Cannabis processing areas equipped with cooler panel walls and ceilings • Roll-up and slide doors equipped with good seals
□ Process Parameters for Proper Operation
• System testing and odor sampling to ensure system efficacy □ Maintenance Requirements
• Filter replacement schedule (quarterly recommended)
• Daily system checks and facility walks
□ Staff Training
4) Complaint Management Procedures
□ Facility Odor Complaint Point-of-Contact Information
□ Complaint Management System description
□ Procedures for Response
□ Community Outreach, if applicable
□ Acknowledgement of departmental access
5) Corrective Action Plan, if required. See Section 5.1.3 for more detail.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com Appendix Page E-3
Cannabis Dispensaries (Retail Storefronts)
Odor Abatement Plan (OAP) Checklist Template
1) Introduction and Source Identification
□ Facility Name
□ Facility Address / Assessor’s Parcel Number(s) (APN)
□ Vicinity & Zoning Map
□ Site Map including entrances/exits, ventilation points □ Description of Facility Operations and Layout (e.g., retail floor, storage areas, security checkpoints)
2) Description of Odor Emitting Activities or Processes □ Identification of Odor Emitting Activities (e.g., display of cannabis products, product handling, packaging removal)
□ Identification of Potential Odorants (e.g., dried cannabis flower, concentrates, infused products)
□ Product Storage Details (including secured areas)
□ Waste Generation and Disposal Practices (e.g., expired product disposal, packaging waste)
□ Operational Schedules (hours of operation, delivery schedules) □ Potential Fugitive Odor Sources (e.g., entrance/exit air exchanges, storage room ventilation, product handling zones)
3) Description of Methods Used for Odor Control
□ Administrative Controls (e.g., odor-free product display protocols, customer handling guidelines)
□ Engineering Controls (e.g., carbon filtration systems, air curtains at entry points, HVAC filtration upgrades)
□ Process Parameters for Proper Operation (e.g., ventilation system performance per mechanical plan)
□ Maintenance Requirements (e.g., filter replacement schedules, ventilation system inspections)
□ Staff Training (odor management awareness, incident response procedures) □ OAP Certification by Certified Industrial Hygienist (CIH) or Professional Engineer (PE) 4) Complaint Management Procedures
□ Facility Contact Information (Odor complaint point-of-contact) □ Complaint Management System (e.g., log system, reporting protocols) □ Procedures for Investigation and Response
□ Community Outreach, if applicable (e.g., contact signage, neighborhood relations) 5) Corrective Action Plan, if Required
□ Steps to Investigate, Address, and Prevent Recurrence of Verified Odor Complaints.
See Section 5.1.3 for more detail.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com Appendix Page E-4
Cannabis Consumption Lounges
Odor Abatement Plan (OAP) Checklist Template
1) Introduction and Source Identification
□ Facility Name
□ Facility Address / Assessor’s Parcel Number(s) (APN)
□ Vicinity & Zoning Map
□ Site Map including all consumption areas, ventilation points, and adjacent uses □ Description of Facility Operations and Layout (e.g., consumption lounge, retail area, private rooms, outdoor patios)
2) Description of Odor Emitting Activities or Processes □ Identification of Odor Emitting Activities (e.g., on-site smoking, vaping, edible consumption with residual odors)
□ Identification of Primary Odorants (e.g., cannabis smoke, vapor emissions, lingering odors)
□ Product Storage Details (if applicable)
□ Waste Generation and Disposal Practices (e.g., ash disposal, used vape cartridge management)
□ Operational Schedules (hours of operation, special events) □ Fugitive Odor Sources (e.g., door openings, patio areas, ventilation exhaust points)
3) Description of Methods Used for Odor Control
□ Administrative Controls (e.g., consumption area restrictions, designated smoking zones, door closure protocols)
□ Engineering Controls (e.g., high-efficiency carbon filtration, negative air pressure systems, enclosed smoking areas, exhaust stack placement) □ Process Parameters for Proper Operation (e.g., air exchange rates, airflow rates, filtration performance standards)
□ Maintenance Requirements (e.g., filter replacements, ventilation inspections, smoke evacuation systems)
□ Staff Training (odor management practices, incident handling, system operation) □ OAP Certification by Certified Industrial Hygienist (CIH) or Professional Engineer (PE)
4) Complaint Management Procedures
□ Facility Contact Information for Odor Concerns
□ Complaint Management System (e.g., community hotline, incident logs) □ Procedures for Response and Documentation
□ Community Outreach, if applicable (e.g., neighborhood meetings, communication channels)
5) Corrective Action Plan, if Required. See Section 5.1.3 for more detail. □ Steps to Investigate, Address, and Prevent Recurrence of Verified Odor Complaints.
See Section 5.1.3 for more detail.
Cathedral City – Regulatory Review - Cannabis Odor Control www.scsengineers.com Page F
Appendix F
City of Cathedral City Licensed Cannabis Business Type and Zoning Maps
Santa Maria, CA July 2025
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0 0.5 1 1.5
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FIGURE #1 GENERAL VICINITY
CATHEDRAL CITY
REGULATORY REVIEW
BUSINESS LICENSES | ZONING MAP
CITY OF CATHEDRAL CITY, CA
Legend
Business Types
Cultivation
Dispensary
Distribution
Manufacturing
Microbusiness
Testing Laboratory
City Limits
City Limits
Zoning
Commercial
Industrial
Open Space
Residential
Santa Maria, CA July 2025
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0 0.25 0.5 0.75
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Legend
Business Types
Cultivation
Dispensary
Distribution
Manufacturing
Microbusiness
Testing Laboratory
City Limits
City Limits
Zoning
Commercial
Industrial
Open Space
Residential
FIGURE #2 ZOOM EXTENT
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BUSINESS LICENSES | ZONING MAP
CITY OF CATHEDRAL CITY, CA
Santa Maria, CA July 2025
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Legend
Business Types
Cultivation
City Limits
City Limits
Zoning
Commercial
Industrial
Open Space
Residential
FIGURE #3 CULTIVATION ONLY
CATHEDRAL CITY
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BUSINESS LICENSES | ZONING MAP
CITY OF CATHEDRAL CITY, CA
Santa Maria, CA July 2025
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Legend
Business Types
Dispensary
City Limits
City Limits
Zoning
Commercial
Industrial
Open Space
Residential
FIGURE #4 DISPENSARY ONLY
CATHEDRAL CITY
REGULATORY REVIEW
BUSINESS LICENSES | ZONING MAP
CITY OF CATHEDRAL CITY, CA
Santa Maria, CA July 2025
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Legend
Business Types
Distribution
City Limits
City Limits
Zoning
Commercial
Industrial
Open Space
Residential
FIGURE #5 DISTRIBUTION ONLY
CATHEDRAL CITY
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BUSINESS LICENSES | ZONING MAP
CITY OF CATHEDRAL CITY, CA
Santa Maria, CA July 2025
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Legend
Business Types
Manufacturing
City Limits
City Limits
Zoning
Commercial
Industrial
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FIGURE #6 MANUFACTURING ONLY
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Santa Maria, CA July 2025
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Legend
Business Types
Microbusiness
City Limits
City Limits
Zoning
Commercial
Industrial
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Residential
FIGURE #7 MICROBUSINESS ONLY
CATHEDRAL CITY
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BUSINESS LICENSES | ZONING MAP
CITY OF CATHEDRAL CITY, CA
Santa Maria, CA July 2025
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Legend
Business Types
Testing Laboratory
City Limits
City Limits
Zoning
Commercial
Industrial
Open Space
Residential
FIGURE #8 TESTING LABORATORY ONLY
CATHEDRAL CITY
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BUSINESS LICENSES | ZONING MAP
CITY OF CATHEDRAL CITY, CA
Santa Maria, CA July 2025
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Legend
1000Ft Buffer
Business Type
Cultivation
Manufacturing
Microbusiness
City Limits
Zoning
Commercial
Industrial
Open Space
Residential
FIGURE #9 1000FT BUFFER
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BUSINESS LICENSES | ZONING MAP
CITY OF CATHEDRAL CITY, CA