I only recently became aware…

I only recently became aware of this application and do not have time to research my response in depth but... approximately 10 years ago, Carmeuse in Beachville Ontario applied for a change to their site plan which has bearing on this application.

Under Carmeuse' original license, the rehabilitation plan was to haul fill into the West Quarry and bring it back close to the original grade. This involved millions of tons of fill and a minimum of ten years to complete the task. After a flood, Carmeuse asked for a change whereby the quarry could remain a lake and not be filled in with soil.
Part of the argument involved the lack of suitable "clean" soil in that kind of volume. That it would be difficult to monitor every load and that the risk of introducing contaminated soil was too high to be worth the risk. Whether contaminated with oil or residual pesticides (including the lingering traces of DDT type pesticides), it was described as not economically feasible to test every load for any number of potential contaminants. Testing would take too long and testing prior to excavating and hauling impractical.

Understand that I am paraphrasing here. I had a copy of the application and read it a number of years ago and as I only became aware of this application yesterday, I have not had time to re-visit the Carmeuse application. I am sure it is still on file with MNRF.

It should be noted that the Carmeuse application was approved - The quarry is to remain a water body.
One would think that if the risk of introducing contaminants to the groundwater was deemed too high at Carmeuse, this application in Caledon should be denied for the same reasons. As a bare minimum, testing of every load, for a variety of potential contaminants, should be performed prior to the soil being excavated and then hauled and dumped into the Caledon Pit (or anywhere sensitive).