Acid Mine Drainage
Submitted by Steve DeMers on Tue, 2017-07-11 00:00
Surface area is sometimes a difficult process to understand. Today we measured the surface area of some sponges and we then made cuts to them and measured the increase. It was difficult for some as it was pretty early in the morning. We weren't quite sure where this activity was going. Idaho City is a sprawled out community in the Boise National Forest. It has a long history of gold and silver mining since its incorporation in 1862. It is very evident of this as you drive up highway 21 from Boise. It is 36 miles of twisting highway to Idaho City. As you near the city you will notice piles of rock, a lot of them. These are mining tailings that have been dredged up from the bottom of Mores Creek by a massive dredging machine. The same process has occurred along Elk Creek which flows through town as well as the Idaho Center for Outdoor Education (ICOE). The Basin School District runs the ICOE and we camped there for the evening. Our instructor, Brian Lawless, informed us that we were tenting in an area that had been hydraulicly mined. Placer mining was also very common in the area as well as hard rock mining. Placer mining is when you remove sediment from the stream bed and run it through a sluice box. Hard rock mining is when you dig holes into the hillside and remove the material, crush it, and then sluice it. All three process expose massive amounts of surface area of rock that were not naturally exposed. Many people, when they think of mining, think that acid is used in the process of mining but in this situation the acid is a byproduct. By exposing more surface area water can come in contact with you also expose more sulfides, which are commonly found in metal bearing mines. Ecologically speaking this can cause a pH change to both the surface and ground water making it sometimes unusable. It is very expensive to clean up when mining companies pull out of an area. Do you think new mines should be permitted in our watershed?