odor complaints

August 21, 2023


Industries commonly have odor complaints, especially as suburbs encroach closer to a facility’s property boundary. Even when using scrubbers and other industrial treatment methods to eliminate odors, they can still cause nuisance problems for facilities.

To address this, environmental engineers compile processed meteorological data and odor complaint information to determine the best course of action to mitigate odor issues and create positive relations with the public.

How it Works
A large beef processing facility in Southern California has received increasing odor complaints from the public over the last five years. Enough that the courts ordered the facility to take action above and beyond what it was already providing. The engineers started by tabulating the complaints, including time, date, and supplemental information such as location, any noted comments, and findings from the regulator upon their inspection. In addition, they compiled all maintenance records from the facility and meteorological data from the adjacent airport to perform a detailed analysis of the odor problem.

By assigning each complaint with its wind speed and direction based on the logged complaint time, the engineers create a map and see that most complaints originated south of the facility when the wind blew from the north, indicating a high probability that this facility was indeed the culprit despite controls in place. Additional revelations included:

• Complaints are most common in the morning.
• All complaints are within the colder months.
• Higher wind speed mitigates odor complaints.
• Processing more cattle does not lead to more complaints, but longer processing hours may correlate.
• Scrubber maintenance reduces complaints.

Resulting Factors
Many factors contribute to odor complaints, but this assessment showed the strongest correlation when the facility performed scrubber maintenance. The scrubbers are control devices on the exit vents of the building that controls pollutants and odors leaving the facility.

Using the study results, the engineers can pinpoint recommendations to control odors. Out of all the recommendations, the simplest and most cost-effective recommendation is Option 1, to increase scrubber maintenance. Employ Option 2 if production is increasing. Options 3 through 5 are less desirable since they are more expensive or could hinder production schedules. Nonetheless, we list them so you have all of your options, as follows:

1. Perform more regular maintenance on the scrubbers, especially during the winter months.
2. Even though the system currently seems to be sized appropriately, get the scrubber manufacturer to upgrade the system if the facility increases production.
3. Install a meteorological tower on site and reduce or halt operations when the winds are slow, from the north, and in the colder months.
4. Add a deodorizing system south of the plant to inject an odor neutralizer in the air into the odor plume.
5. Construct a wind barrier or heavy-duty fans south of the plant to intersect and force more dispersion of the odorous plume.

Sustainable and Proactive Approach
The beef processing facility study determined quarterly maintenance should significantly reduce odors. Moving forward, the facility can refer to its SCS study if experiencing conditions that could increase the possibility of odors and, importantly, show regulators the facility takes a proactive approach to community concerns.


Jeffrey LeadfordMeet the Author: Jeffrey Leadford has 10 years of experience in the air quality field. His specialties include air dispersion modeling, emission inventory production, GIS mapping, and air monitoring. At SCS he creates emission inventories, reports, and runs air dispersion modeling on industrial sites in the Pacific Northwest. Mr. Leadford is a Professional Engineer licensed in Oregon, and received his Bachelor’s of Science degree in Chemical Engineering from the University of Colorado. He is also a licensed FAA Remote Pilot. Contact Jeffrey or your local resource at .


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Posted by Diane Samuels at 6:00 am

April 4, 2022

Agriculture Odor Management

When we think of farming, most of us think of fresh air, big skies, and acres of open land. One of the oldest industries is transforming to meet the increasing demand for commercially grown produce, wine, hemp, and cannabis with emerging agriculture odor management strategies.

Agricultural commerce brings jobs but also a few unwelcome odors. Hemp farms have distinct odors, vineyards spray elemental sulfur smelling of rotten eggs on wine grapes, and cannabis facilities can smell at different stages of plant growth. Even a farm growing cut flowers, when fertilized, will have a measurable smell.

Air Quality
A wine’s aroma is usually floral, citrus, or earthy, and Thanksgiving Day is the smell of home and hearth. However, getting these agricultural products grown and processed can sometimes be smelly. Many environmental technologies are being adapted for use in agriculture. Some are the result of industrial risk management and even landfill technologies for controlling odors and maintaining good air quality. As with landfills, they work best when designed for a specific site with site-specific wind conditions and site-specific distances from the nearest neighbors.

Hemp and cannabis growing facilities, both indoors and out, get odor complaints, so operators plan ahead to manage them. Odor intrusion for facilities coexisting in dense urban areas or com-mingled with other industries nearby tends to get more complaints, where the odor source is more complicated to pinpoint. On larger tracts, greenhouses, and small farms, air-misting systems or air blocking vegetation are more common.

“We can assess the potential concentration (odor strength) using known chemical surrogates emitting from cannabis. However, this approach has considerable weaknesses since many of the odor-causing compounds are difficult to detect at concentrations near their odor detection thresholds,” says Paul Schafer of SCS Engineers. “The ratios of emitted compounds are variable based on cannabis strain and time in the plants’ lifecycle, drying/curing/processing method, and varying atmospheric chemistry following emission.”

Some proposed cannabis greenhouses filing for a permit use an internal carbon filtration system to prevent fugitive pot odors from becoming a neighborhood nuisance. This indoor odor-control system would replace outdoor air-misting systems used by some greenhouse operations and commonly at landfills. The outdoor systems neutralize smells by changing the molecular structure of escaping vapors and work best when designed to work with air patterns. They are useful when there is a larger buffer zone because odors typically rise or flow in patterns.

Production hubs on larger acreage, even property utilized for agriculture for decades, require remediation. Many firms use modern greenhouse structures encompassing hundreds of thousands of square feet with processing plants. Schafer explains “As an odor and air monitoring expert and environmental engineering consultant, my job is to assess how various environmental technologies work under specific conditions to these companies and at times to the public. We use and investigate specialized technologies for industrial or agricultural use because they require specialized odor reduction, are safe, and can be successfully utilized to manage air quality and odors.”

As farming, businesses, and housing coexist across the nation, SCS’s water, soil, and air management teams are tweaking environmental technologies to help communities and new-age farmers remain good neighbors. Schafer who is the firm’s Ambient Air Monitoring expert puts it this way, “As engineers and consultants, we help communities and industry thrive together.”

Stormwater Management
Farmers or growers strive to include more ethical and sustainable growing practices, such as higher standards for water use and purifying their wastewater for reuse. As urban areas grow and farmland shrinks, stormwater management is essential to help new-age farmers operate sustainably and meet growing stormwater regulations that protect water supplies and the environment.

These aren’t the only greenhouses we work in.
The proven sustainable environmental solutions SCS Engineers offers to the agricultural, construction, extraction, manufacturing sectors, and municipalities help them attain their cleaner operating goals. As an environmental consulting and construction firm, we produce measurable technologies and programs that capture and reduce more greenhouse gases for private and public clients than any other environmental firm in the Americas.

Learn more on our website.






Posted by Diane Samuels at 6:00 am