[Old School]

I dont know how I didn't keep it in perspective, I mentioned in the first post that this was a ash pond, and not a coal sludge pond.

From what I have read, the construction of this pond, and the slurry ponds here are very similar, and have similar safety guidelines. Supposedly they are over designed to handle a massive amount of precipitation in a short period of time, but as this shows, thats not always the case.

I didn't mean to insinuate that you had not, but to keep it in perspective during future discussions.

Let me assure you that a ash pond and a slurry impoundment are two totally different structures. Regardless both are designed to accommodate their purpose, but like anything else if they are not built and maintained according to the design and all of the precautions are not taken during construction this can happen. As I said I'm not all that familiar with ash ponds, but I think ash ponds are built above ground with a dike completely encircling the pond (similar to a flood wall) and is designed to have water pumped into it and not to control water from rain events. Where as slurry impoundment is designed to have water pumped into it and also to be able to maintain maximum 30 and 40 year rain events. According to article that I have read on this matter ash ponds only have to be approved by the state in which they are located, where as coal slurry impoundments have to follow guidelines established by Surface Mining Control and Reclamation Act (SMCRA) set by Congress in 1977, and be approve by MSHA and State agencies along with the Army Corp of Engineers. I'm not sure of the time frame it takes to have as ash pond approved, but a slurry impoundment will take up to at least 5 years from the beginning to final approval.

Depending on the size of the ash pond the dike surrounding it could be constructed in within a few months, where a coal slurry impoundment could take several years to construct.

According to the fact sheet released by the TVA, "the volume of the Kingston ash pond was within its permitted limits". The fact sheet went on to say, "The most recent annual inspection was conducted in October 2008. The formal report is not complete for this inspection, however a preliminary report shows that a "wet spot" was found, indicating a minor leaking issue. There were no significnt problems found that indicated that the dikes were unstable to the point of failure"