Source: http://greenanswers.com, June 8, 2011
By: Julie M. Rodriguez
Across the US, abandoned mines languish awaiting cleanup efforts – up to 500,000 of them. An estimated 40% of Western rivers are tainted with the toxic discharge of these sites. There are at least 7,300 abandoned mines across the state of Colorado alone. 450 of these are already known to be leeching toxins into surrounding watersheds, but no one has yet stepped up to make any cleanup effort.
Why? According a recent Denver Post article, community groups, mining companies, and even state agencies claim that by attempting cleanup they may incur legal liability under the Clean Water Act if they accidentally worsen the contamination — they fear they could be subject to federal prosecution for polluting waterways without a permit. Reassurances by the EPA that “good Samaritan” groups will be partially shielded from liability have done nothing to ease these worries. Without formal legislation offering protection, few will risk going forward with cleanup efforts.
The Colorado Department of Natural Resources estimates 1,300 miles of streams in the state are already known to contain measurable amounts of toxic substances. Some have even been declared “biologically dead” due to the extent of the pollution, and more sites risk becoming too contaminated to support life the longer cleanup is delayed.
The main danger posed to these waterways is due to Acid Mine Drainage, or AMD. Sulfuric acid forms when the sulphides in rocks are exposed to water and air in the open mine shafts, and along with microbial activity, it works to dissolve heavy metals and toxins such as cadmium, copper, arsenic, cobalt, lead, and zinc. Among the effects of these chemicals are possible cancers, organ and nerve damage, and gastrointestinal problems. This toxic brew seeps into groundwater or is carried away in snowmelt, poisoning aquatic life and contaminating drinking water and agricultural water supplies. This natural leeching process can continue for hundreds, or even thousands of years, unless efforts are made to combat it.
This is not the only danger posed by these mines. Powerful chemical agents, such as cyanide, are used during the mining process itself to separate the minerals and ore, and these chemicals can spill or leak from the mine into nearby water supplies. Erosion of the exposed earth in these mines can smother vegetation, destroy habitat, and clog riverbeds. The location of many mines in arid states also raises a possibility of air pollution due to dust.
The Obama administration and Secretary of the Interior, Ken Salazar, have promised action to break the gridlock and protect good Samaritans, as well as devote resources to watershed restoration projects, but two years after these promises, little progress has been made. Colorado lawmakers have not had luck persuading Congress to pass legislation on the issue.
Even as this crisis mounts, the mining industry and local economic development groups are pushing to open new mines in areas already suffering from pollution. In Colorado, this contentious issue revolves mostly around proposed Uranium mines. Unfortunately, in many towns, mining offers a more lucrative alternative to the jobs currently available – mainly involving retail work. While legislation from the 1970s prohibits companies from abandoning new mines, the environmental impact of new sites is not negligible, especially when extracting radioactive substances.
Eastern states are not immune to the issue of abandoned mine shafts either, of course – old mines, mainly coal, stretch from Florida to New York, concentrated in West Virginia, Pennsylvania, and Kentucky. Water contamination itself has been documented in all 50 states.