The mysterious source of foul odor that has plagued Mount Dora for years may have been identified by consultants in the city and Lake County.
Now the question is what to do about it.
A Mid Florida Materials Mount Dora landfill at State Road 46 could produce hydrogen sulfide gas that emits a stimulating smell, according to an 83-page report from a consultant funded total of $270,000 from two local authorities.
The study exonerates the city’s sewage treatment plant and also notes that weather patterns in the area exacerbate the problem.
“The Mid-Florida Mount Dora Landfill has the most impact on the odor conditions in the study area,” the report concluded. “It has been further observed that mild wind conditions prevent dispersion and foul odors accumulate in the area, leading to more serious odor conditions.”
This study addressed “odor conditions and odor sources” near ground zero for malodors. Areas near Sullivan Ranch, Stony Brook, and the junction of US 441 and SR 46.
City officials have chosen to subcontract the California-based V&A Consulting Engineer, who is based in California, to help support the subcontracting, among other tasks.
“The final report allowed us to determine that the smell was not being released from the landfill, as expected by V&A,” said Andrew Marcian, Mount Utility Operations Director for Dora Utility & Plant Operations. “We’ll be holding a meeting with some of our stakeholders next week to determine the best approach to moving this forward.”
Investigators acknowledged that the disposal site, known as the “construction and demolition landfill,” was not fully accessible during the study, and all observations were made from the site’s boundaries.
Mid-Florida material has issued a statement pledging to review the findings. “Our facility is fully compliant with applicable air quality regulations and will address DEP concerns,” it read.
Investigators identified several scent hot spots within the landfill, including retention ponds, vents, and “work surfaces” of the landfill.
Although no specific sources of hydrogen sulfide have been named, demolished landfills can include dry wall waste. This contains sulfur that emits the smell of rotten eggs when wet.
The report also includes many “weak” odor sources observed during the study. This includes odors that come from the Carlaf and Gold Flower Cannabis Facility on Brit Road, Niles Road.
“Slight odor” was detected at both facilities and later identified as cannabis, “not similar to the odor observed in the study area.” The cannabis facility was judged “impossible” because it caused a permanent foul odor that led to research.

Over the years, multiple locations have been suspected as sources of foul odor, particularly landfills and urban wastewater treatment plants along James P. Snell, were driven in 441.
Dorayama then took steps to correct the situation, including installing a $500,000 carbon biofilter in 2022 and adding a monitor to detect hydrogen sulfide at wastewater treatment plants in March 2023.
However, the smell persisted, and the Florida Department of Environmental Protection issued a consent order in November 2023 demanding the city increase its odor mitigation efforts.
The first study, written by consulting firm Kimlee Horn, showed that the smell was “very unlikely to come from the wastewater and collection system,” but left them unsure of what the perpetrator was.
Drumcount Councillor Cal Rolfson said the latest research has completely cleared the city of smell responsible and allows city officials to focus on moving the DEP forward and mitigating odors forever.
“This exemplifies the city of Mount Dora in my opinion with clear and compelling evidence that says it’s not a problem and not a problem for us,” Rolfson said. “But that’s our problem in that we need to work with (FDEP) and do something about this. So the smell goes into our city. So we have a responsibility to contact the person in charge and make sure we handle it appropriately and legally.”
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Original issue: May 9, 2025 6am Edt