Aurora MS 6 14975 Bayview Ave. Aurora, Ontario

In October  2010 Albarrie Geocomposites Ltd. had the privilege to install our secondary oil containment system for Power Stream. This was our 3^rd project for Power Stream this year and 8^th overall. This site has 2 transformers, one that already had containment but wasn’t working and one that required containment which we used our standard excavated earthen perimeter solution.  The one that already had containment was not expelling rain water and is the one that I will be talking about.

We can see that this is a sensitive area where there is a water storm pond adjacent to the substation.

It is a perfect site for Albarrie’s SorbWebTM Plus System , which will not allow any oil to escape or 0 parts per million in the event of a failure.

 

This is a 10Mva transformer that was installed in 1973 with 3180 imperial gals or 14,457 Liters of transformer oil.

 

Here we see how the system only held water and didn’t have the available volume for the transformer oil in the event of a catastrophic failure.

The depth of this containment was approximately 40” or 1.0m which was also close to the water table. The design was to excavate only a portion of the existing stone until we achieved the proper volume required. An impermeable liner would be installed and it would drain the water out of the containment with the use of wick drains. The Oilmat and other SorbWeb layers would follow on top.

 

 

 

The area is graded and leveled.

The existing liner is cut at the new depth and removed.

Under the transformer........

was the toughest part!

The entire area is covered with a 4” layer of sand which will provide a firm solid base over the existing large stones and we can grade the sand so the wick drains will have enough slope.

The exit point for the wick drain is drilled through the concrete wall.

The impermeable liner is strapped to the perimeter and the transformer piers, the floor is covered with a double layer and taped.

The edge is sealed with silicone caulking so that the water will not get in behind the material and is directed where we want it to go.

The entire floor is then covered with 2” of sand to aid in the drainage process. Note: wick drain is not in this picture at this point yet.

The wick drain is laid down in the center, the sand was not only graded from the back of the containment to the outlet but also from the concrete walls to the center. This will ensure that there will be no standing water.

All the wick drains are connected together using the product connectors. Here we see a ‘Y’ with the unused ends taped off to prevent any sand from entering the system.

The wick drain then exits the containment through the predrilled hole in the concrete wall.

 

The perimeter and transformer piers are then strapped again with the impermeable liner using a smaller 2’ strip folded in half. The bottom side of the liner is double beaded with silicone caulking and the Oilmat is laid down on top of that.

A bead of silicone is beaded along the edge of the Oilmat and blended into the edge using a piece of cardboard. This will seal the open edge of the Oilmat as well as seal it to the liner.

The top side of the Oilmat is double beaded and loose copolymer is sprinkled along the edge. The impermeable liner is then folded down and glued to the Oilmat.

Next we lay down the adsorbent layer that will glue to the silicone beads that are pictured above.

A bead of silicone is then placed along the liner edge and will complete the total of 6 lines of silicone beads that oil must get past to escape the system.

The final bead is then placed along the strapped liner connection point, again preventing any liquid from migrating in behind the system.

Loose copolymer is sprinkled along the edge.

The area is covered with a woven geotextile which is intended to separate the system from the fire quenching stone and will transfer any liquid laterally.

The containment is then filled with the required fire quenching stone which in this case is a washed crush limestone. Here we see them using a stone slinger which can be a time saving process.

The stone is graded and leveled to the designed height.

Doesn't the above picture look better than this one

We then started on the wick drain on the outside of the containment with a trench dug

The trench exits the fence and turns north towards the pond. It continues until we achieve a respectable 1% slope. Wick drains require a minimum 0.5% slope.

The trench is lined with a non woven geotextile…..

and the wick drain is laid in the trench.

The wick drain and trench is then filled with a minimum 12” cover of washed stone.

Then it is wrapped in the non woven geotextile.

At the end of the wick drain we dug a hole to create a gravel sump.

Again we lay in more non woven geotextile and fill it with the washed stone. This will maintain that the end of the wick drain will stay clear of any foreign debris or even small animals migrating into the system.

The stone is wrapped with the non woven and backfilled with more stone. The rest of the trench is backfilled with native material.

The SorbWeb TM Plus installation is now complete.

 

If you have any questions concerning the installation of this product please contact the undersigned.

Prepared by: Mike Dowds
Albarrie Geocomposites

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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