Update — Tuesday, December 5, 7:03 a.m.: Construction has ended.
To enhance safety, the TTCis replacing all of underground diesel tanks at its bus garages with above-ground tanks.
The TTC operates eight bus garages, six of which already have above-ground tanks. It intends to upgrade the last two, starting with Birchmount Bus Garage from mid-January to late summer 2016.
During the project, crews will:
- dig out and remove two underground tanks from the south side of the property, west of the parking lot;
- replacing underground infrastructure that connects the tank to the bus garage; and
- installing two new above-ground tanks at the site.
All work takes place on TTC property from 7 a.m. until 7 p.m.
According to the TTC, above-ground tanks allow staff to detect fuel leaks earlier than underground tanks, improving safety. The tanks have double steel walls — a sealed tank within another sealed tank. If the inner, or primary, tank leaks, the outer, or secondary, tank would safely contain the leakage. The space between the tanks is a vacuum with a fuel-leak detection system, so staff can quickly detect any perforation of the primary tank.
Tanks have also passed impact-testing. Jersey barriers and bollards will further protect above-ground tanks from any impact damage. All tanks are ULC-approved fire-rated. (ULC — Underwriters Laboratories of Canada — Standards develops and publishes standards and specifications for products affecting safety. The Standards Council of Canada of Canada has accredited ULC to certify, validate, test, inspect and audit products, and advise and train personnel.
Even with these precautions in place, the TTC wants to further reassure nearby residents about diesel fuel. It says that diesel fuel must be atomized or compressed before it can ignite. For example, if someone dropped a burning match or cigarette onto leaked diesel fuel, it would not burst into flames.