An end-pit lake is part of the reclamation process. If you take a look at the leases of the oil sands, you'll see that they have to return the leases to the control of the province in a state that they have—I think the terminology is—an equivalent ecological capacity to the pre-mine state. Now, please do not ask me to define what constitutes an equivalent ecological capacity, because in most cases people are still trying to figure that out.
If you take a look at that activity, you will see there are some things called dry landscape options, which are uplands that will be remediated and reforested. Then there are wet landscape activities, which involve end-pit lakes, and by lake I mean wetland that's probably got at least five metres of water in it. There will also be some wetlands—these are supposedly part of the plan—and then there will be streams that join these up together. When the province has accepted that they have been remediated to standard—the watershed will integrate back into the normal range of the Athabasca—I have no ability to predict when that would actually occur.
The end-pit lake is a strategy to effectively build some wetland component into this reclamation activity. Basically you take a mined-out area, you put some form of tailings in the bottom, usually mature fine tails, you then effectively put a water column on top of that, and you try to have a situation where—and this may be done through fertilizing or it may be done through planting—you end up developing a biological film at the interface on the floor of the lake. It's called the benthos, the biological film that sits between the water and the sediment. Most of these naphthenates and pHs are subject to biological degradation and they will break down through time in a water column. Some of the work I've done shows what happens and how the toxicity changes when that occurs. Effectively, you then have a situation where you have a lake that has water on the top and a naturally occurring biofilm over the material, and it should, through time, develop into a natural lake that becomes part of the reclamation strategy. This end-pit lake strategy is actually fairly commonly used to reclaim strip mining of coal in the States. The difference there is that they don't put tailings in them. This is the big question as to whether or not it's viable. In base metal mining they use end-pit lakes, but it's a totally different type of use. It's part of the reclamation strategy.
The tailings ponds you see on the leases now will not be there when the thing is done; that is my understanding. I'm not an engineer; I know nothing about how they're going to do that. All I'm trying to determine is the toxicity of the materials as one of the indications as to the viability of these systems.
