Voices of Water: Bill Hopkins
Bill Hopkins has studied the effects of coal ash and associated contaminants on aquatic organisms for over 15 years and has published more than 50 scientific papers on the subject. This Tuesday we were very fortunate to visit one of his study sites in South Carolina.
There, the Department of Energy has facilitated critical long term studies on the ecological effects of coal ash settling basins. As Hopkins points out, it’s not acute disasters like the TVA spill, as horrible as they are, that should be our primary concern about ash disposal,. The real culprit lies in the long term costs of mixing water and coal ash.
Let’s start by talking about what we’re seeing piled up in the middle of this meadow, all this coal ash.
This is primarily fly ash which is a major byproduct from coal combustion. Coal itself is a concentrated source of trace elements in an organic matrix and when coal is burned you basically volatilize that organic material and you’re left with an even further concentrated source of trace elements - things like Selenium, Arsenic, Cadmium, Chromium, Nickel, Thalium, Boron.
And so the concern with this material is that it is produced in high volumes and has very high levels of a variety of elements that are potential health concerns both to humans and to fish and wildlife.
So why do we accept having fly ash in our environment?
The production of ash is the hidden cost of clean air. We’ve cleaned up our air but in doing that we’ve basically concentrated those potentially toxic substances into a solid waste. And so the big struggle that we face in society is deciding what to do with the more than 120 million tons of this material that are produced every year in the US.
Should fly ash be regulated as a toxic substance?
What I can tell you is that currently the way ash is managed in ponds, in my opinion, is not safe. A lot of ash is placed in these settling ponds that we’re going to talk about today and that particular technology has a lot of risks associated with it.
So my concern after studying this for 15-16 years is that when we mix these materials with water we are creating a long-term legacy of contamination of aquatic systems because the trace elements liberated from coal combustion don’t just go away, they persist in the environment.
Then, what is the take home message when we’re dealing with coal ash?
I think there are ways to manage or recycle these wastes in a safe way. I firmly believe that, but I don’t think mixing them with water is one of the answers.
It’s become more and more clear to us that when you mix ash with water bad things can happen and when you minimize contact with water, the evidence we have suggests that there’s not that big of a problem. The unfortunate part is that it tends to cost more money to landfill the materials, creating a trade off. You have to balance financial decisions and political decisions with ecological decisions.
And at the end of the day the ecological decisions, in my opinion, should be the primary driver, because that affects all of us.