On a sunny day in October, Mike Arnold swings open the door to his barn storehouse outside Eugene, Oregon, and takes a big whiff. The smell hits him immediately, a sweet and skunky wall of cool air. “Smells like money,” Arnold says within his Missouri drawl, gazing out at row after row of makeshift wood-and-mesh shelving, where 12,000 pounds of marijuana were lying to dry.

Following close behind, in colorful glasses as well as a tweed jacket, is definitely the cannabis engineering virtuoso in charge of keeping that pungent odor safely inside the confines of the building: 39-year-old Daniel Gustafik. Gustafik continues to be building out pot grow rooms for 20 years, designing novel solutions for anything from irrigation to lighting to humidity control in hidden sub-basements and also on off-grid homesteads long before anyone could even conceive of Bob Marley-branded weed sold openly in sleek boutiques. He and his company, Hybrid Tech, are now considered to be among the best within the game in terms of putting together industrial-scale legal cannabis operations. Before 4 years, they’ve completed spanning a hundred projects in 37 states and 2 countries.

Even while marijuana air quality plan becomes increasingly mainstream, not everyone is feeling chill about legalization. Pot reeks, and pot being grown or processed at commercial scale reeks even more. Some states and municipalities have included specifications about odor control inside their medical and recreational marijuana regulations.

But cannabis’s federally illegal status creates all kinds of thorny problems. Last June, a 10th-circuit court in Colorado decided which a family who complained concerning the “noxious odors” coming from a cannabis venture next door had sufficient grounds to argue the aroma had hurt their property values, and can therefore sue for triple damages under federal racketeering law. The ruling sent shockwaves through the legal weed industry, triggering similar lawsuits in Oregon and Massachusetts, and potentially establishing a precedent through which private citizens can use federal law to topple locally licensed pot businesses. Which means that marijuana’s distinctive stink could actually be worse for your legalization movement than anything Attorney General Jeff Sessions has done, and the continued success of state-legal weed is influenced by rigorous odor-proofing.

Take Arnold’s cavernous drying barn, nestled among rolling hills and maple trees. This, Gustafik says, is his magnum olfactory opus: a 5,000 sq . ft . facility, outfitted in a mere 21 days, and operating in a county dmdwjs the strictest marijuana scent control rules on the planet. Before Oregon legalized recreational weed, a lot looser medical cannabis law was in place for many years, attracting inconsiderate growers accustomed to the black market. The noise, traffic and stink annoyed locals who, subsequently, annoyed officials using their complaints. When it came time to regulate adult use, some counties preemptively took a hard line. With a meeting to determine which these rules would look like in Clackamas County, one community member compared the smell to “skunk dipped in turpentine and gym socks.” Consequently, the Clackamas ordinance ultimately specified anything from the angle of exhaust vents to the effectiveness of the fans utilized to circulate air. Lane County, where Arnold’s barn is found, ultimately chose to make use of the same language in their ordinance.