A group of Rock Hill, Missouri residents filed a lawsuit against cannabis processor New Growth Horizon, alleging the company's Proper Brands facility emits persistent odors that damage nearby properties.
The complaint, filed in St. Louis County Circuit Court, accuses the facility of creating "noxious odors" that constitute private nuisance, public nuisance, and negligence. Plaintiffs claim the smells invade their properties and have caused measurable property damage.
Rock Hill, a small municipality in St. Louis County with roughly 4,500 residents, has seen cannabis facilities open following Missouri's medical marijuana program launch in 2018 and adult-use sales beginning in February 2023. The state's rapid expansion has brought processing facilities into residential areas, creating friction in some communities.
The Complaint
The lawsuit targets New Growth Horizon's processing operations at its Proper Brands facility. Processing facilities, which extract cannabinoids and manufacture products like concentrates and edibles, typically generate stronger odors than retail dispensaries due to the large volumes of plant material handled during production.
Missouri's medical marijuana regulations require facilities to implement odor control systems, but the state has not published specific odor mitigation standards. The Department of Health and Senior Services reviews odor control plans during the licensing process but enforcement of odor complaints has varied across jurisdictions.
Neighborhood complaints about cannabis facility odors have become common in legal markets nationwide. Denver received over 2,000 odor complaints in 2022, while California communities have implemented setback requirements and air filtration mandates in response to resident concerns.
Industry Response
New Growth Horizon has not yet filed a response to the lawsuit. The company operates multiple cannabis brands in Missouri and markets itself as a premium processor focused on quality extracts and products.
Odor mitigation technology has improved substantially in recent years. Industrial carbon filtration systems, negative air pressure controls, and sealed processing environments can reduce emissions by 90% or more, according to equipment manufacturers. But these systems carry significant costs, particularly for smaller operators.
"The technology exists to manage odor effectively," said one Missouri cultivation consultant who requested anonymity. "The question is whether facilities invest in it upfront or wait until they face legal pressure."
What's Next
The lawsuit seeks unspecified damages and potentially injunctive relief, which could force facility modifications or operational changes. Similar cases in Colorado and California have resulted in settlements requiring upgraded filtration systems and adjusted processing schedules.
Missouri municipalities have limited authority to regulate state-licensed cannabis facilities under current law, though some have adopted local ordinances addressing setbacks and operational requirements. Rock Hill has not passed cannabis-specific odor regulations.
The case could set precedent for how Missouri courts handle nuisance claims against licensed cannabis businesses. With the state's adult-use market still expanding and new facilities coming online, odor disputes are likely to increase without clearer regulatory standards.
St. Louis County Circuit Court has not yet scheduled a hearing date for the case.
This article is based on original reporting by ganjapreneur.com.
