In business, a million dollar mistake refers to an error that has three main
characteristics. First, it’s a big one. It has large consequences that are hard to
correct. Second, it’s definitely not intentional. Those responsible were doing
their best. However, third and most importantly, it was avoidable.
Over the last 20 years, academic and commercial research and development
initiatives have led to the creation of new restoration techniques where acid
generating tailings are sequestered in highly stable structures. Covers with
capillary barrier effects (CCBE), elevated water tables and covers with
geomembranes are now commonly used as tools to rehabilitate mining sites no
longer in operation. Prediction models estimated that these structures could
remain stable for hundreds of years… Or so we thought.
In a nut shell, nothing on CEBBs, elevated water tables or coverages with
geomembranes will prevent the growth of trees. In fact, often nothing is
completely lacking as far as their nutritional needs are concerned. Conditions on
these structures are far from ideal, but not so that tree growth will be null. It
might be slow, mortality rates might be high, but in the end tree growth is almost
unavoidable.