Stockton Mine

       Today we visited the Stockton Mine which is harvesting one of the purest forms of coal in the world. The mine has been in operation for nearly 100 years. Our visit was focused on the environmental impact aspect of the mine. The folks at the mine have only been aware of the "green" movement for around 5 years, and has only just begun to address the issues in the last 18 months. 

Some of the main issues addressed in our brief meeting included water management, acid rock damage (ard), and direct transfer. 

In January, 2007, the Stockton Mine was granted resource consents by the West Coast Regional COuncil to discharge treated mine water and settled water from Stockton Mine into the Mangatini Stream and to dose the stream with finely crushed limestone to improve the downstream water quality by raising the pH level. This reduces the concentration of metals that dissolve in the water and improves water quality. The reported water quality findings thus far have shown exponential improvement. The problem with this is, when you start to confront water quality issues in an area with a pH of something around 2-3, exponential improvement is not hard to show. 

The so called "mildly" acidic acid rock damage forms when rain and air combine with the pyrite which is widespread in rock located within the Stockton Mine. Most likely a major contributor to the pH issues in the water quality of the Mangatini Stream. I have trouble calling a pH of that measure "mild." According to this description, stomach acid would be comparable to hydrogen peroxide. However, many recent efforts have gone into developing systems to insulate rock dumps from the elements and so minimize the extent of environmental impact of ARD.

Another of the issues covered was a process that Phil Rossiter, Environmental Program Manager, termed "direct transfer." Direct transfer is, in simpler terms relocation of environmental barriers. Much work has gone into transplanting environments into sections of the mine called "rehabilitation" zones. The problem with the rehabilitation zones that I found was that they looked nothing like the native bush that surrounded the mine yard. The rehabilitation zone was dry, and arid. It contains no soil except for some sort of a mesh made of straw. 

The second example of direct transfer comes about with the issues of powelliphanta Augustus covered in the previous blog. One of the main objections that I have with this process, besides the aforementioned side effects, is  best said by Cath Wallace earlier on our trip. When considering moving a species to another location, you must first ask yourself why that species isn't in that location in the first place. Most likely, there is a reason. This is not verbatim from Cath, but you get the idea. Any species, and most especially those that are considered endangered, may not be able to handle the stresses of being extracted from their native environments. 

Overall, it was definitely an eye opening experience in many aspects. Allthough I feel that there is much more work to be done, the bottom line is that this is a coal mine, and they are in the business of producing a product which supplies a need in demand. I must give credit where credit is due and state that the Stockton Mine is most likely one of the world leaders as far as environmentally conscious coal mines, but my own conscious in my head continued to scream throughout the brief meeting, "what aren't you telling us Phil?" 

          "rehabilitation zone"

rehabilitation