PIT PHOTOS/UNR ENVIRONMENTAL SCIENCES
Cove pit in Lander County during the early stages of filling. The lake level is higher now.
WHAT’S TO BE DONE WITH WATER LEFT BEHIND BY MINING?
BY DENNIS MYERS
I
t’s an awesome sight, even though it’s really only a hole in the ground. An open pit mine is an injury to the Earth that, unlike some other such injuries, is not reclaimed by the planet all that easily. Roads can be overgrown in a couple of years. Open pit mines will be there for centuries. Some of them go so deep that the mining happens below the water table, the water being constantly pumped out to permit the mining to continue. But always, sooner or later, the mining comes to an end. Then, so does the pumping. The water returns to its natural level, only now it’s a lake. They’re called pit lakes. There’s not much to be done about them. Mining corporations are not required to replace their divots and it’s not likely the public could afford to do anything about it. Environmental scientist Glenn Miller recalls when someone told him what it would take: “It costs a buck a ton to put the dirt back into the pit. If you’ve got a billion tons of dirt—.” The thought didn’t need finishing. The scale of the matter is huge, yet is largely unknown to the public. In a 2002 article in Southwest Hydrology magazine, Miller described it:
“Gold-mining pit lakes in Nevada, when filled, will contain more water than all of the reservoirs within the borders of this arid state. An estimated 35 pit lakes from all types of hard rock mining are expected to form, containing from less than 100 acre-feet up to about 540,000 acre-feet of water. On a statewide basis, all of the existing reservoirs within the state (excluding Lake Mead) contain approximately 600,000 acre-feet. In contrast, pit lakes in the Humboldt River Basin alone will contain 1,500,000 acre-feet, and evaporation from their surfaces is expected to remove the equivalent of five percent of the flow of the Humboldt River at Winnemucca each year.” In a desert state, it’s simply not responsible to ignore that much water. Miller: “Thus, from a water resource perspective, pit lakes are important to Nevada, and the quality of the water in them will determine their future use, as well as their effects on the aquifer, wildlife and ecosystems.” So, if it’s cost effective for the pits to be filled, what’s to be done with them, and with the lakes? Right now, the policy is simple—fence them off. That protects the public from what is, after all, an extremely dangerous aftereffect of mining. But just doing that and no more troubles some folks.
“LOVELY LAKE PIT” continued on page 11
OPINION
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NEWS
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GREEN
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FEATURE STORY
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ARTS&CULTURE
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IN ROTATION
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ART OF THE STATE
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FOODFINDS
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FILM
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MISCELLANY
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AUGUST 16, 2012
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RN&R
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