Imperial Oil Limited has been convicted of one violation under the Environmental Protection Act (EPA), fined $900,000 plus a victim fine surcharge of $225,000 and given 90 days to pay, for discharging a contaminant, namely slop oil, into the environment which caused or was likely to cause an adverse effect.
Imperial Oil Limited (IOL) owns and operates a petroleum refinery and chemical manufacturing plant located on Christina Street South in Sarnia.
The refinery uses steam tracer lines along its pipelines to prevent the pipelines from freezing during the winter. Steam tracer lines are small tubes that carry steam and are located underneath the pipes’ insulation to keep them warm. Leaks in the steam tracer system are relatively common at the refinery.
In January 2021, IOL employees discovered a steam tracer leak along an elevated pipeline containing slop oil. Slop oil is a waste product that is typically composed of crude oil, water, and waste solids. It contains various contaminants which may include hydrogen sulphide.
IOL avoids conducting non-critical steam tracer repairs during the winter months due to the risk of pipelines freezing and splitting during the repair process. IOL schedules repairs when the weather is expected to be warm. Repairs are prioritized based on a number of factors including urgency, repair time, resources, and forecasted temperatures.
In 2021, IOL categorised steam leaks into three categories to determine the priority for repairs to be completed.
The steam tracer leak in January 2021 was designated as a second level priority where the risk level was considered acceptable to leave unrepaired if a freeze occurred (below zero temperatures). Repairs were planned for March 2021.
In April 2021, prior to scheduled repairs, steam escaping from the steam tracer line leak bored a hole in the nearby slop oil line resulting in a spill of approximately 1,150 litres of slop oil. Subsequent air monitoring did not detect hydrogen sulphide, volatile organic compounds, or gas vapour.
The discharge of slop oil caused adverse effects to persons at two nearby businesses and residents of Aamjiwnaang First Nation, including the loss of enjoyment and use of property and interference with the normal conduct of business.
Individuals reported experiencing eye, nose and throat irritation, as well as headaches and nausea. Strong odours were also reported which restricted movement and activity and caused health and safety concerns.
As a result of the leak, IOL revised the steam leak repair prioritization criteria to include the potential impact to the community as part of the highest priority criteria when assessing relative repair priority of steam leaks at the refinery.
Following the new steam leak repair prioritisation criteria, IOL would characterise the steam leak identified in January 2021 as the highest priority repair.
The ministry’s Environmental Investigations and Enforcement Branch investigated and laid a charge which resulted in the conviction.