photo: AP/MTI, Gyoergy Varga
Wastewater or sludge storage lagoons are designed, in part, based on statistical probability of annual precipitation and evaporation amounts. The data behind these estimates generally don't take into account contemporary or projected weather extremes associated with man-induced climate change. There is powerful anecdotal evidence of the risk such storage lagoons can pose, as the poor villagers of Hungary could easily tell us about if we were in direct communication. Accuweather mentioned this risk in today's news.
Image: NOAA Atlas 14, Vol 2 (2004)
Rainfall 200% Higher Than Normal This Summer in Some Parts of Europe
As reported by Accuweather.com:
Data show that late-spring and summer rainfall in some areas of central Europe from Poland to southern Hungary and Serbia was more than 200 percent of normal. If rainfall were as high at the disaster site, walls holding back the sludge may have been weakened, even contributing to the breach that released the spill.
What happened with the aluminum ore processing lagoon in Hungary may be a symptom of a much larger scale risk coming. Really the same added risk is posed by coal ash lagoons in the USA if they were designed for less rainfall and more evaporation than are or will be experienced due to radical weather extremes.
This particular risk, of lagoons designed for drier times, is not so much a problem with gold or uranium or other mining lagoons throughout much of the American West because the climate extreme concern there, presently, is drought and natural dryness (as pictured above).
Some wastewater or sludge lagoons pose added danger because of non-climate related factors: Due to bad design in the first place, poor construction or maintenance practices, pressure from management to cut corners on materials or size to save money, and over use beyond design capacity (over filling with waste water and/or sludge).
This is a slow bullet that can be dodged.
Looking at climate risk in general, it seems to me that the risk of over wet lagoons bursting is more of a clear and present danger than sea level rise. Yet there are engineering solutions on the ground for this risk. Basic inspections and engineering reviews are the starting point.(USEPA did just this for existing coal ash settling lagoons.)
There are hundreds, perhaps thousands, of anaerobic lagoons in use at Concentrated Animal Feeding Operations (CAFOs) in the USA alone. I recently read about one dairy operation for 10,000 dairy cows being opened. The trend is for more concentration at this scale. ONe cow puts out as much excrement as around 14 people. You can't spread manure in the winter. Hence, a burst lagoon for such a mega-dairy in the upper Midwest would loose as much crap as a small city would accumulate over 3 months.
A ruptured human sewage settling lagoon could be even more dangerous, spreading disease organisms across downstream villages and into water supplies. Numerous small communities utilize sewerage settling lagoons as the primary method of treatment and some even accept industrial waste water.
The aftermath of the TVA coal ash spill
First steps for risk mitigation.
Now would be the time to do some overlay planning: mapping out areas where large wastewater and sludge lagoons exist or are likely to be permitted along with the likelihood of increased precipitation and/or decreased evaporation.
Instead of waiting for people to be up to their armpits in corrosive red mining waste or pathogen-filled poop, some basic risk management studies should be performed based on a re-examination of engineering design tables and consideration of where radically changed weather extremes could add risk.
More posts on coal ash lagoon bursts.
Overview of Recent Toxic Coal Ash Spills :
Yet Another Coal Ash Spill, This Time in Luke, Maryland (Upriver
USEPA Evaluates The Fly Ash Mess Nationally: First Self-Reporting ...
Coal State Electric Bills Rising 7% To 100% - Even Without Cap