We have an idea based on the hydrogeology. The exact numbers are known only by Alberta Environment, because they commissioned extensive studies by private consulting companies. They are not public yet, but they have used those studies to establish a framework for groundwater management. However, we do know that given the geology and the hydrogeology of the region, those aquifers right above the McMurray formation are paleovalleys, buried channels, and have a very small capacity to keep groundwater in the reservoir as storage. We also know that their recharge is very small.
I'll just give you two numbers quickly. Imagine you have aquifers that contain approximately 15 million cubic metres of water. If the recharge in the area is in the order of one million to two million cubic metres of water per year, it will take approximately 10 years to refill them.