Case Studies

Case Study 1: Gas Monitoring at Landfills

Methane is an extremely potent greenhouse gas that has 80 times the warming potential of carbon dioxide. Given its massive impact on climate change, governments around the world are racing to pass regulations that require strict monitoring of its emissions and atmospheric concentration.

The industries targeted by those monitoring regulations are Petroleum, Mining, and Waste Management. The common denominator among those sectors is that they all operate major facilities in areas that have a limited telecommunications infrastructure, and are therefore limited to manual methane measurement using handheld sensors, a process which is expensive, time consuming and produces intermittent readings. In some facilities, continuous monitoring can be carried out, but it requires laying thousands of feet of cables to connect sensors to a SCADA hub, or using LoRaWAN wireless sensors which have a very limited range.

“We have no idea how we’ll be able to meet those regulations once they kick in.”

— Senior Project Manager, Major Landfill, Ontario, Canada

Spero Analytics’ continuous monitoring mesh network solves all those problems.

To prove that, we deployed a large gas monitoring network at a major landfill in Ontario, Canada to provide operators with real-time, cost-effective methane surveillance on-site with no need for cellular connectivity. The network ran continuously with 100% uptime, despite the landfill’s IT systems being offline. Data from the network detected a methane hot spot and generated a wealth of information on methane emissions at the landfill. As we continue working with the waste management sector, we aim to become their go-to source for gas monitoring and real-time, off-grid environmental surveillance.

Case Study 2: Landfill Odor Detection and Mitigation

The Problem of Odorous Emissions from Landfills

Though most landfills in high-income countries employ significant resources to maintain a green, visually attractive facility, home values adjacent to those landfills are 14% lower, on average, compared to similar properties in the vicinity, with the discount easing by roughly 5.9% per mile of separation up to 2-3 miles away. The biggest driver of this perceived lower property value is the fear of foul odors reducing residents’ quality of life.

The cause of these odors is a combination of hydrogen sulfide (H₂S), methane, and volatile organic compounds (VOCs) – gases which are released during the decomposition of organic waste and which create the characteristic “rotten egg” or garbage-like smells that can travel kilometers depending on weather conditions. In recent years, population growth and urban sprawl have brought residential areas closer to existing landfill sites, amplifying conflicts. Provinces such as Ontario, British Columbia, and Quebec report the highest volumes of odor-related complaints, with some municipalities logging hundreds of reports annually from a single facility.

Several high-profile cases highlight the severity of the issue. In the Greater Toronto Area, the Green Lane Landfill near London, Ontario, and the Beechwood Environmental site in Halton Region have repeatedly made headlines for persistent odors that residents describe as nauseating and disruptive to daily life. Similarly, British Columbia’s Cache Creek landfill and Hartland landfill near Victoria have prompted formal complaints and regulatory interventions after strong smells affected nearby neighborhoods for weeks at a time. Environment Canada and provincial ministries have fined operators and mandated odor mitigation plans, yet many residents argue that enforcement remains inconsistent and that fines are too low to drive meaningful change.

To address the problem, landfill operators are adopting new technologies, including enhanced gas collection systems, daily cover requirements, biofilters, and odor-neutralizing misting systems. For many Canadian communities living near these sites, the issue remains a frustrating reminder that effective, long-term solutions are still needed. As with most issues in modern facilities, the problem has more to do with a lack of data collection than inaction by landfill operators; landfills can be as large as 1,000 acres, so triangulating the precise location where landfill gas may be leaking, and knowing which way the wind will carry that gas is crucial to enabling prompt action to minimize the effect of the odorous leak. Without this information, decision-makers at landfills are left to rely on complaints to start the odor-hunting and resolution process – a process which leaves the residents frustrated.

What Makes Odor Detection Challenging

Detecting and quantifying odorous emissions from landfills is technically challenging because odors are not a single compound but a complex, ever-changing mixture of hundreds of trace volatile organic compounds (VOCs), reduced sulfur compounds (hydrogen sulfide, mercaptans, dimethyl sulfide), ammonia, and amines – often present at parts-per-billion (ppb) or even parts-per-trillion (ppt) levels. Human noses remain far more sensitive than most chemical sensors to many of these molecules (the odor threshold for methyl mercaptan, for example, is around 0.07 ppb), so by the time an instrument registers a reading, nearby residents may already be overwhelmed. Compounding the problem, these compounds are released episodically from different “hot spots” across a site (leachate lagoons, fresh waste cells, cracks in cover material, or gas-well leaks/failures) and are heavily influenced by temperature, barometric pressure drops, wind direction, and atmospheric inversion layers that can carry a faint plume several kilometers while diluting it below most sensors’ detection limits. Adding to the difficulty is the phenomenon of odor masking, synergism, and fatigue: some compounds cancel each other out, others amplify perceived intensity when mixed, and repeated exposure quickly desensitizes both people and some sensor technologies.

Spero Analytics’ AirAware System at Brady Road Landfill

Landfill Gas Collection System Wellhead This collection system consists of a network of pipes buried underneath the landfill to capture the gasses produced by the decomposing waste – which are mostly methane and carbon dioxide. The system uses a slight vacuum created by a blower or pump to draw this gas out of the landfill through the wells. Once collected, the gas is moved through the pipe network to a central point where it is safely flared.

It was thought that the source of fugitive (odorous) emissions was from the above-ground wellheads, which connect to the LFG system and allow operators to sample the landfill gas and adjust the vacuum pressure in that particular collection well. In some cases, those wells can malfunction, leading to fugitive gas escaping and wafting over to the nearby residential development.

To help operators identify the precise leaky well before the odorous gasses build up at the nearby residential neighbourhood, we deployed our AirAware odor detection-and-alert system to detect any leaks from those LFG wellheads. The system comprises a proprietary mesh network of low-power sensors ring-fencing the facility which continuously monitor for methane spikes (which indicate a leak in the LFG system), as well as wind measurements on-site. Once a spike is detected, an alert is sent in real-time to the operator with the likely coordinates of the source, leading to a much more rapid response to odorous leaks and odor complaints from the nearby community.

AirAware Sensor overlooking residential area

Case Study 3: Fully Automated Gas Flux Monitoring

Soil and water bodies (like lakes, oceans, and swamps) are enormous reservoirs of gases such as carbon dioxide, methane, and hydrogen sulfide – all of which are potent contributors to climate change and potential hazards to human health and safety in high enough concentrations.

As a result, many tools have been developed over the years to help researchers and environmental engineers measure the rate (or flux) of gas emissions emanating from soil and water surfaces. The most reliable and trusted instrument they use is known as a flux chamber.

Flux chambers are used today in settings such as landfills to evaluate the performance of biocovers, oil sands facilities, and by environmental researchers seeking to study GHG emissions.

Operating Principle of a Static Flux Chamber

In its simplest form, a flux chamber is a dome or hollow square enclosure which gets placed on the soil to create an an airtight seal with the ground. The chamber has a number of gas ports designed to be connected to a gas analyzer via standard 1/4 inch tubing. As gas builds up in the chamber, the user starts a stopwatch and notes down the concentration of the target gas (in ppm, ppb, or %LEL), every 20-30 seconds for a total of 5-10 minutes. What they end up with is a table of time vs. gas concentration.

Diagram illustrating the operation of a static gas flux chamber

The gas flux can then be calculated as:

Static Flux Chamber Flux Calculation Equation

Where:

Variable	Description	Units
F	Mass Flux of gas	g/m²/day
V	Volume of the chamber	m³
A	Area of the soil covered by the chamber	m²
dC/dT	Rate of change of the gas in the chamber	ppm/s
P	Atmospheric pressure at the site	Pa
R	Ideal Gas Constant	8.314 Pa.m³.K^-1.mol^-1
T	Absolute temperature of the air inside the chamber	K
M	Molar Mass of the gas	g/mol
86,400	Seconds per day (Conversion factor)	s/day
10⁶	Parts per million (Conversion factor: 1 ppm = 10⁶)	Unitless

It is highly advised for static flux chambers to take at least two additional measurements, both in the same spot and in the vicinity to capture any temporal or spatial variability in emissions.

The advantage of this method of flux calculation is its simplicity; all that is needed is a static chamber of known volume and footprint, a portable analyzer, and a length of tubing. The major downside is that it provides only a snapshot of gas emissions at the site, and it requires the operator to lift the chamber and re-seat it on the soil (or water surface) every time they wish to take a measurement. This is because the emission measurement requires the gas to build up in the chamber in order to calculate a flux, and this wouldn’t be possible if the gas is allowed to reach saturation in the chamber. In short, those chambers fail to provide a full picture of emissions at a given site and they require significant manual (and error-prone) effort on the part of the user.

Dynamic Flux Chambers

To solve the problem of gas build-up necessitating the constant reseating of the static flux chamber, dynamic chambers are used instead by many operators, particularly researchers who often require more granular emission data.

The dynamic flux chamber is identical to its static counterpart, but with two additional features: An exterior gas tank, commonly referred to as the ‘sweep gas’ tank, and an interior fan; the gas tank is connected to the chamber via a length of plastic or silicone tubing.

Diagram illustrating the components and gas flow of a dynamic flux chamber

As with static flux chambers, the dome is placed on top of the soil/water surface. Gas from the sweep gas tank – which contains a known concentration of the target gas we are trying to measure from the ground (e.g. carbon dioxide) – is continuously injected into the chamber at a known flow rate. The operator then proceeds to monitor the concentration of the target gas and calculate the soil/water flux rate using the following equation:

Dynamic Flux Chamber Flux Calculation Equation

Where:

Variable	Description	Units
F	Mass Flux of gas	g/m²/day
Q	Flow rate of sweep gas into the chamber	m³/s
C_out	Concentration of the target gas in the chamber outlet	ppm
C_in	Concentration of the target gas in the sweep gas inlet	ppm
A	Area of the soil covered by the chamber	m²
M	Molar Mass of the target gas	g/mol
R	Ideal Gas Constant	8.314 Pa.m³.K^-1.mol^-1
T	Absolute Temperature inside the chamber	K
P	Absolute Pressure inside the chamber	Pa

Fully Automated, Wireless, Real-time Flux Chambers

Over the past 12 months, Spero Analytics has collaborated with researchers at Carleton University in Ottawa – with funding from Environment and Climate Change Canada – to develop a first-of-its-kind fully automated flux monitoring platform which requires no user intervention after installation and no cellular/power infrastructure on site.

The system works by continuously measuring the gas concentration inside the chamber, calculating the gas flux based on the rate of increase in concentration, then transmitting the data wirelessly to a gateway, which then makes the flux available online in real-time for end users. Once a measurement is taken, the chamber is automatically purged, then re-sealed for the next measurement.

Using Spero’s CottonCandy mesh networking platform, a number of those chambers can be placed at a site, allowing for multiple concurrent measurements, which continuously capture the temporal and spatial variability of gas emissions on site.

Case Study 4: Water Resource Monitoring for Isla Urbana

Mexico City, one of the world’s most populated cities, is currently in the midst of a water crisis that threatens the health and well-being of its 20 million inhabitants. The problem is particularly acute in peri-urban areas, which are largely disconnected from municipal water distribution networks.

Isla Urbana Rainwater Harvester Installation Isla Urbana is a Mexican NGO which is helping solve this major problem by installing rainwater harvesting systems in homes and schools across the country. To date, they have installed over 3,200 systems.

One of the challenges Isla Urbana faces, however, is regular monitoring and maintenance of those systems. Currently, this monitoring is done manually by evaluators, who visit the installation sites periodically. Given the inaccessibility and remoteness of some of the homes where those systems are installed, this process is tedious and cannot be done frequently enough to detect problems with the systems. Wireless monitoring is infeasible due to the lack of strong cellular coverage in many of the communities where the systems are installed.

Spero Analytics is helping Isla Urbana solve this problem by deploying mesh networks equipped with water level sensors and rain gauges to monitor the performance of their rainwater harvesters. Through a collaboration with researchers at the University of Toronto, we hope to provide Isla Urbana with real-time insights on their systems, thereby minimizing the need for manual auditing and freeing their resources to focus on installing more harvesters across the country.

MENU

Book A Demo