A toxic spill near Randle Reef, lovingly nicknamed Blobby by the media, is saying its final good night. Cozily tucked in between sheet pile walls, the most contaminated sediment on the Canadian side of the Great Lakes will be in permanent hibernation soon.
Putting a cap on Randle Reef represents one of the largest initiatives to remediate Hamilton Harbour to date and rightly so.Seven football fields’ worth of contaminated sediment will be isolated in a man-made box, no longer slowly leaching across the Harbour floor and available to the wildlife that call Hamilton Harbour home.
Hamilton Harbour’s water quality has improved enormously over the past 40 years, so where did this pollution come from? It’s a legacy.
A legacy dating back to the 1800s. Hamilton Harbour was chosen as a dumping ground, but with the intention to save Lake Ontario where Burlingtonians and Hamiltonians get their drinking water from.Waste products from coal gasification, petroleum refining, steel making, and municipal wastewater and sewage were all released to the Harbour. Some of the toxic waste accumulated next to the current-day Stelco facilities on the south shore.
Many years of testing and research went into understanding what was down there and how much. The main contaminant was polycyclic aromatic hydrocarbons, or PAHs in short. PAHs are known to be persistent, toxic and carcinogenic.
After years of delays to select, design, and fund a solution, the project is almost at the half-way mark. The project has three distinct stages: building a box, filling the box, and putting a lid on the box.
The first task was building the box. Double steel walls were built around the perimeter of the most contaminated sediment in 2016 and 2017. If you lived near the shoreline, you may have heard the pounding of sheet piles carrying across the water. These sturdy walls extend 24 feet below the Harbour bottom so you can be sure the contamination is well contained.
The second task was removing the sediment from between the walls and placing it inside the container. The space between the walls was then filled with clean, crushed rock. The inner wall was sealed creating an impermeable barrier while the outer wall gives structural stability.
Dredging of contaminated sediments from around the container is underway. A hydraulic dredge uses cutter suction to essentially vacuum the Harbour floor and pass the sediment by pipeline into the containment facility. As the box fills, the overlying water will be pumped to a treatment facility specific to Randle Reef and then released into the Harbour after testing. The majority of this dredging work will be completed in 2019 and will remove approximately 99.7% of the PAH blob.
Importantly, this type of dredging reduces the possibility of toxin emission from sediment to air. All the safety checks for air emissions, water emissions, and leakage tests have been surpassed and monitoring will continue through all phases of the project.
The lid, which is the last phase of the project, will consist of many layers that when put together create an exceptional seal and a strong base for port activities. Upon completion of the project the Hamilton Port Authority will own the facility and will be responsible for its maintenance.
The permanent hibernation of Blobby is one giant leap forward in the remediation of the Harbour and a massive community initiative that will be so important to the futures of Burlington and Hamilton. As for delisting the Harbour as an Area of Concern, there’s still more work to do, but in the meantime, say goodnight to Blobby.
Last modified: March 5, 2019