Natural gas heats our homes, provides electricity, and supplies us with many valuable consumer products. Sour gas is natural gas that contains measurable amounts of hydrogen sulphide (H2S). The gas is colourless and flammable and smells like rotten eggs. Sour gas represents about one-third of all natural gas produced in Alberta and can be used to recover sulphur. However, sour gas is dangerous, and energy companies must handle it safely and responsibly.
H2S Sources
H2S is a toxic gas formed by the breakdown of organic materials found in natural gas, oil, sewage, swamps, stockyards, and pulp and paper processing. Even at low concentrations, you can recognize its rotten egg smell. At higher concentrations, it can impair breathing. Because H2S is heavier than air, it accumulates in low-lying areas.
Critical Sour Gas Wells
A critical sour gas well is a well that could potentially release large quantities of H2S, causing significant harm to nearby communities. Companies must be cautious when drilling these wells.
In determining whether a sour gas well should be considered critical, we examine factors such as the complexity of the drilling operations and the number of people who live in the area. See EnerFAQs: All About Critical Sour Wells for more information.
Protecting Albertans and the Environment
We recognize the dangers of sour gas and routinely review and improve our regulations to help protect Albertans and the environment. We are, in fact, internationally recognized as a leader in the development and implementation of sour gas regulations. Our work includes
- reviewing and approving detailed drilling plans that consider H2S training and supervision;
- ensuring that there is an emergency response plan in the event of an H2S release;
- evaluating the distance between a sour gas facility and nearby residences; and
- conducting regular inspections and publishing our findings on our Compliance Dashboard.
Incident Response
When an incident occurs, such as a blowout or sour gas leak, we dispatch our air monitoring units (AMUs)—sometimes referred to as “sniffer trucks” – to measure gas concentrations. This monitoring technology helps us reduce risks to the public and the environment and helps us respond to incidents safely and efficiently.
Our AMUs detect and measure two types of gas emissions: sulphur dioxide (S02) and H2S.
Learn more about how we respond to energy-related incidents.
