Dealing with dust, odor, and noise to placate landfill neighbors

Don’t Be a Nasty Neighbor!

Dealing with dust, odor, and noise to placate landfill neighbors

 • The journal for Municipal Solid Waste Management Professionnals (MSW) USA • Article by Lori Lovely • September 5th, 2016 

“Whether a landfill is preparing a legal defense or merely trying to be a good neighbor by reducing and containing odors, OlfactoExpert Inc. consultants can provide necessary information.

First, an audit is conducted in order to determine the source of odors. “We study them one by one,” explains Yann Contratto, owner. “We collect samples from all sources—the surface, the wastewater pond, and the arrival of fresh waste—and analyze them.”

Use of flux chamber allows OlfactoExpert to quantify odor emitted per square meter and per minute. Here for fresh waste.

Once the odor samples have been collected and analyzed, teams prioritize the sources, analyze the data, and generate level II impact studies, including mapping that makes quantitative and qualitative studies possible. Knowing each features for each sources, it become easy to compare them, so also to sort them. This first step is already a very important milestone to be conducted to face issues accordingly.

An odor impact study integrates sources of smells, the topography of plant, wind, climate, and where odor goes, using 3D odor dispersion modeling software. “It demonstrates why one neighbor is more affected than another,” says Contratto. “Measuring at the source of emission establishes the impact of all these factors.”

He says the study is “very representative of the reality of emission,” and that simulation source by source enables them to determine what works best and what costs the least.



Fresh waste covered (one month)

Here from leachate

Leachate pond odor sampling

Here from waste water treatment process

Waste water treatment process









The Smell of Success


According to Contratto, 20% of sources are responsible for 80% of odor complaints. “Complaints usually come from new neighbors, and it’s usually the same: less in winter, worse in summer, when it’s humid and hot.” Because wind and climate escalate the problem, it becomes a “major issue” if the location is close to a city or ocean. . . or where cities authorize new development.

“New residential complaints make up about 80% of all complaints.” That’s because people who work at the landfill become accustomed to the odor. “After five years, you can’t detect a lower level of odor,” says Contratto.

He lists four dimensions of odor:

1 – Concentration per cubic meter
2 – Intensity on a scale of 0 to 10
3 – Quality, or the name of the smell: fresh waste, biogas, pond odor, leachate, compost, leaves, and herbs
4 – Hedonic tone, or the degree of pleasantness or unpleasantness (This is the only dimension that is subjective.)

Team of professionals are following many features among weather data conditions during sampling

Team of professionals are following many features among weather data conditions during sampling, but also instrumentation’s flow rate and quality features

Considered a legal expert in olfactometry since 2006, Contratto says odors are often a legal issue more than a technical one. Because odor can affect the value of your house, class action lawsuits arise with frequency. In fact, he says they have multiplied by three each year for the last four years in the US. That’s why his services are so valuable.

Measuring odor is a new branch of science. “The level of error was too high until 10 years ago,” indicates Contratto, “but tools have changed everything.”

These tools record a very precise measurement of odor concentration, similar to decibels in sound measurement. Using specific materials, OlfactoExpert measures the landfill surface, liquids, the flare, and leaks. He even measures the difference of emission with different amounts of cover.

But it has taken time to be accepted. “We have to educate the customers and the courts that the tools are reliable,” acknowledges Contratto. “Few are specialized and knowledgeable at that level to give advice. You must know chemistry and math.” Although he considers it a niche market, he says business is growing and expanding into other industries, such as agriculture, tires, wastewater, and the kind of plant.

He says that if you follow his recommendations, up to a 40% reduction of emissions is possible. Suggestions can include covering with sand or dirt to reduce the impact on neighbors, adjusting duties during the hours of operation, or making changes to accommodate the prevailing winds.

But, beware, he cautions: “Most managers make the same mistake—they trust product salesmen. Most products are masking agents, not controlling agents.” Contratto makes clear: OlfactoExpert hires legal, technical experts who make recommendations on actions, but not specific products”.

Flare gas & odor analysis and monitoring

Flare odor efficiency

Sampling en tête de puit

Biogas leak detection