The modelling that has been done is sufficiently complex that the only way you're actually going to find out if something like an end-pit lake works is to build one and monitor it for about 10 to 15 years and determine whether it will work.
That's what's being done at Syncrude and at Suncor. Remember that it's up to the companies to remediate. So, frankly, if that strategy doesn't work, the province is not going to accept the lease lands back and they're going to have to go back to looking at alternative strategies.