On November 16, 2009, installation of a secondary oil containment system began in Port Hope, Ontario. The system was designed for one transformer and two additional vaults containing oil. The containment boundary in this case will be an excavated earthen perimeter.
The first step of this project, was to expose the grounding grid with the use of a vacuum truck. This is done to facilitate excavation and to prevent damage to the grid from any equipment, since all of the copper will be visible.
The containment boundary is marked out, pad sizes are verified to ensure conformance with the design and excavation begins.
Upon completion of excavation, the grounding grid is now placed along the banks and will be re-attached to ground rods and at all areas that were previously disconnected. With the grounding grid in place the installation of the sorbweb system can now begin.
The first sand layer is installed followed by a layer of non woven geotextiles along the slopes and banks.
A double layer of impermeable liner is installed to seal around the perimeter. The impermeable liner is also installed around all concrete pads and intrusions with the use of plastic strapping and concrete anchor nails.
The first layer of the liner is sealed at all seams and corners allowing the oilmat to be installed and sealed to it. Loose copolymer is added at all edges of oilmat to maximize sealing.
The top layer of the liner is now lowered and sealed onto the top of the oilmat. The adsorbent layer is now placed on top of the oilmat.
The first layer of woven geotextiles, and the second sand layer are now installed.
The second layer of woven geotextile can now be installed allowing the addition of the fire quenching stone. The final step prior to the containment being completely filled, is the sealing around the strapping and intrusions. This prevents any oil from escaping around the pads in the event of a catastrophic failure.
An additional step on this site was the sealing of the vaults. Even though they do contain a large volume of oil, the oil must not be able to escape the system.
Finally the stone is leveled and the grounding mats are re-attached as they were prior to construction.
In conclusion, this project went smoothly and the containment was completed in four days. The weather throughout the project was mixed and upon completion, the client was happy with the system.
Prepared by Maurice Quesnelle
