Response to a Letter of Inquiry from the Mimico Residents Association Board
Sent on behalf of Rachael Fletcher, Director, Central Region, Ministry of the Environment, Conservation and Parks
The ministry has completed its technical report titled “The Ministry of the Environment, Conservation and Parks: Brenntag Canada Inc. Fire Off-Site Environmental Monitoring Summary Report, Date: November 16, 2023”. A copy of the full report is attached.
On August 11, 2023, a 6-alarm fire occurred at a chemical distributor, Brenntag Canada Inc. (Brenntag), located at 35 Vulcan Street, in Etobicoke, Ontario. Brenntag reported that approximately 700,000 litres of oil (soybean and petroleum-based oil), transmission fluids and solvents were stored at the facility at the time of the fire. The event led to heavy emulsions/slurry of oils and fire suppression materials along with impacted fire douse water to enter the municipal storm sewer system and discharge into Mimico Creek, Humber Creek and the Humber Bay Park area of Lake Ontario.
Between August 11 and August 31, 2023, the ministry sampled for potential impacts from the fire to the environment and human health. The ministry’s technical review includes its’ findings on impacts to water, sediment, and air as a result of the fire and fire suppression activities. The report also includes stream bank soil sampling and vegetation survey results.
A summary of the technical report findings is provided below:
- On the day of the incident, the ministry deployed its mobile trace atmospheric gas analyzer (TAGA) and undertook real-time ambient air measurements of a wide array of air contaminants upwind and downwind of the fire to determine any potential impacts to the local air quality. All measured air contaminant levels were far below their respective emergency screening values, confirming there were no local air quality concerns resulting from the fire.
- Several milestones have been achieved in the cleanup to date, with strict oversight provided by the Ministry of the Environment, Conservation and Parks (ministry) and its regulatory partners. This includes the completion of large-scale containment and cleanup work, with efforts now transitioning to restoration of the natural environment.
- The ministry conducted extensive sampling of water, sediment, stream bank soil and vegetation to identify potential impacts of the run-off to Mimico Creek, Humber Creek and Lake Ontario.
- Water and sediment samples were collected at multiple locations along Mimico Creek, Humber Creek, and Lake Ontario, and analyzed for petroleum hydrocarbons, volatile organic hydrocarbons (VOCs), per- and polyfluorinated alkyl substances (PFAS), polycyclic aromatic hydrocarbons (PAHs), and metals.
- The main sources of contaminants were petroleum hydrocarbons and fire suppression materials. The results showed a decline in the concentration of contaminants over time and with increasing distance from the discharge points in the impacted waterways, and are returning to pre-spill/urban background conditions, with low levels of residual contamination remaining in the impacted waterways following the incident. Sediment sampling results suggest that the current concentrations of contaminants would not have a significant impact on the resident organisms.
- Stream bank soil and vegetation samples showed elevated concentrations of contaminant compared to samples collected in non-impacted areas. These results suggest that the elevated concentrations in the creek bank vegetation adjacent to and downstream from Brenntag likely originated from the fire incident.
The Ministry and Environment Canada and Climate Change are currently in the process of verifying the status of the cleanup before restoration work can begin; this process is anticipated to extend into November.
Determination of the cleanup’s effectiveness will be based on several factors including visual observations of the cleaned-up waterways, comparison of monitoring results to applicable guidelines and background conditions, and assessment of whether additional cleanup is necessary or would cause greater harm to the environment. Should additional cleanup work be required, the ministry will ensure Brenntag will initiate the work immediately.
Brenntag has submitted a restoration plan that outlines how the impacted environment (water, soil, sediment, vegetation) will be assessed, restored, and monitored to demonstrate the effectiveness of the cleanup efforts. The timelines proposed in the restoration plan include field surveys starting in spring 2024, with monitoring going well into 2025.
Should you have any questions on the above, please contact the ministry’s Toronto District Office Duty Line at 416-326-3381 during regular business hours or send an email at environment.toronto@ontario.ca.
Sincerely,
Rachael Fletcher
Dr. Rachael Fletcher, PhD
Director, Central Region
Drinking Water and Environmental Compliance Division
Ministry of the Environment, Conservation and Parks
5775 Yonge St., 8th Floor
Toronto, ON M2M 4J1