AMD, Fish, and the Dog Days of Summer
by Andy McAllister, Watershed Outreach Coordinator
Sampling an abandoned mine drainage (AMD) discharge during the “dog days” of summer can be a refreshing experience, because AMD temperatures remain fairly constant, often in the upper 50°s F. Groundwater in the upper 300 feet or so is normally a couple of degrees warmer than the average yearly air temperature; in Pittsburgh, that average yearly air temperature is 53° F. In the hottest summer months, this cool water can be quite a relief for coldwater fish and overheated biologist alike.
Fish such as trout can be found in some AMD-polluted streams near the confluence with another stream. They use the cool water as a thermal refuge, swimming in and out to escape the warmer water in larger streams. Fish will consume macroinvertebrates living in the AMD-impacted stream, but more often than not, metal precipitate and pH levels prevent any sustainable macroinvertebrate populations to serve as prey, forcing the fish to venture back to the warmer stream to find food.
This cooler water may be just the ticket to help turn a liability into an asset: mine discharges continue to be examined for their potential in aquaculture and cooling buildings or power plants.
For more information…
Abandoned Coal Mines Provide Liquid Assets for Fish Farmers
by the WVU Aquaculture Food and Marketing Development Project
Geothermal Mine Water as an Energy Source for Heat Pumps
by the Canada Office of Energy Efficiency
Mine Water for Power Plant Cooling
by the WVU Hydrogeology Research Center
Use of Mine Pool Water for Power Plant Cooling (870kb PDF)
for the US Department of Energy