Among the many threats to Kern County's air quality, cannabis doesn't rank high. But it's on the list.
The plant puts out volatile organic compounds, the precursors to smog, albeit on a dramatically smaller scale than something like petroleum refining. Arguably more offensive is the plant's pungent smell.
Not many but enough complaints have been filed in eastern Kern that the air district there has repeatedly been called out to investigate reports of offensive odors. The calls center around California City, where commercial cannabis production and processing operations are permitted.
The Eastern Kern County Air Pollution Control District recently listed cannabis production and processing among six significant sources of air pollution in the region. It has conducted an enforcement sweep and now holds more than a dozen companies to air filtration standards that reduce harmful emissions and sheer stink.
As new applicants come along in Cal City's growing cannabis industry, the air district is looking for improved technologies for making such operations better neighbors.
"We like to keep our, as I say, nose to the ground," said Glen Stephens, the district's air pollution control officer.
Kern County is not new to issues surrounding dank odors wafting from cannabis operations. in 2017 county government prepared an environmental review that ended up recommending an extensive set of measures for controlling the smell, including greenhouse ventilation requirements.
Because outdoor operations were tougher to control, staff recommended only allowing indoor grows if the Board of Supervisors wanted to permit cannabis operations, which it did not.
Countywide, illegal growing operations have proliferated, especially in the desert areas, and Lorelei Oviatt, director of Kern's Planning and Natural Resources Department, pointed to those criminal operations as possible sources of odor. She said by email offensive smells "are the least of the threats from them."
Notably, county government hasn't received any complaints about hemp, Oviatt wrote, noting the plant puts off less smell than its psychoactive relation cannabis.
At the San Joaquin Valley Air Pollution Control District, which covers the only city in Kern besides California City that permits commercial cannabis, Arvin, there's only ever been one reported complaint about cannabis odors.
A spokeswoman said by email that single nuisance was determined to be emanating from a residential property and so the district passed along the information to law enforcement. She had no update.
Stephens at the air district in eastern Kern said four complaints about cannabis odors have come in during the last two years. But he hasn't issued even one violation of notice to comply, he said, in some cases because the source couldn't be identified.
At one point the district conducted a sweep of Cal City and identified half a dozen operators without proper air permits. All those companies applied for and got permits, Stephens said, and now they get inspected once a year like the rest.
The district quantifies operators' emissions and requires emissions-control measures including the use of a carbon cannister containing activated carbon. It acts like a filter to keep smells from escaping an enclosure.
A newer technology Stephens referred to, but which he has not seen put to use in eastern Kern, masks odors using a product that spreads through the atmosphere to make cannabis odors less noticeable.
"It smells kind of like plants but it doesn't smell like cannabis," he said.
Stephens said complaints about odors have become more rare, and he likes to think that's because of the steps the district has taken to control the smell. But his expectation is that complaints will kick up again.
As the industry grows and becomes more lucrative, he said "there's always potential" for odor.