Cities Deploy Drones and Electronic Sensors to Pinpoint Industrial Stenches
Urban areas in California and Iowa are turning to automated monitors and data-tracking tools to detect and control neighbourhood odours.
At a glance
- Cities such as Milpitas and Des Moines are using drones and sensor rings to locate and measure sources of industrial odours.
- The US EPA does not regulate odours as pollutants, leaving local authorities to manage stenches as urban sprawl closes distances.
- Advanced electronic monitors provide real-time chemical and wind data, replacing subjective human sniff tests with verifiable evidence.
Municipalities and residents across the United States are deploying advanced monitoring technologies, such as sensor networks and drones, to pinpoint and mitigate pervasive industrial stenches. From Milpitas in California's Silicon Valley to Des Moines, Iowa, local authorities are seeking objective data to replace human sniff tests and address complaints caused by landfills, processing plants, and urban growth.
In Milpitas, local authorities ordered the operators of the 342-acre Newby Island landfill to deploy drones and automated chemical sensors. The mandate requires the site to systematically measure odour-causing compounds and automate the capture of landfill gases. For decades, residents living nearby endured hours of bad smells daily as urban infill gradually reduced the buffer between housing developments and waste facilities.
Urban expansion is driving similar conflicts worldwide. Because the U.S. Environmental Protection Agency does not regulate environmental odours as pollutants, local and state governments must handle disputes independently. Odour mitigation typically involves absorbing smell-causing compounds, burning them off, or altering them chemically. While high-grade systems can eliminate 90% or more of offending compounds, some facilities resort to masking agents, which environmental experts warn do little to solve the problem.
Data-Driven Accountability
Tracking the origin of foul air has historically relied on olfactometry—human panels personally assessing smells. However, municipal authorities are transitioning toward electronic sensors that correlate chemical readings with local weather patterns.
In Des Moines, officials faced persistent complaints over an odour known locally as the "Eastside Funk," linked partly to industrial meat processors. The city now spends approximately $240,000 annually on a sensor ring developed by environmental monitoring firm Kunak. Paired with weather stations, the sensors track chemical concentrations alongside wind directions in real time, allowing officials to trace plumes back to specific facilities.
The real-time tracking has prompted major industrial investments. For instance, meat processor Smithfield Foods installed a $2 million regenerative thermal oxidiser designed to destroy foul-smelling compounds, though it maintains it is not the source of local complaints.
Experts note that completely resolving odour issues remains difficult due to the sheer surface area of landfills and the subjective nature of human perception. Studies indicate that as smells become more unpleasant, people grow increasingly sensitive to them, ensuring that the pressure for precise tracking will only intensify.
Source: BBC Science.
Questions and answers
- Why does the US government not enforce limits on bad smells?
- The US Environmental Protection Agency does not regulate environmental odours as pollutants, leaving states and municipal governments responsible for setting rules.
- How do electronic odour monitors work?
- Devices known as electronic noses measure chemical compounds in the air and combine those findings with weather station wind data to determine which site produced the plume.
- What methods do industrial sites use to eliminate smells?
- Facilities generally absorb odours, convert them chemically into less smelly compounds, or burn them away using equipment like regenerative thermal oxidisers.
