Exposure: Acid Mine Drainage
(c) Jason Zheng
Mining in Virginia
by Saima Hedrick
According to the Virginia Mining Association, approximately 49% of Virginia’s electricity comes from coal. As the tenth largest producer of coal, Virginia has 108 coal mines and produces 21 thousand tons of coal per year. The process of extracting of coal from non-valuable rock produces a slurry of tailings, small mineral particles suspended in water, which is dumped in designated areas. When these tailings come in contact with rainwater they produce sulfuric acid that can seep into the local waterways and groundwater killing off organisms and making the water undrinkable. This leakage is known as acid mine drainage.
Sometimes the tailings can also contain trace elements that can biomagnify in the organisms living in the waterway. Arsenic and Chromium, both Class I carcinogens, can be released into the water via tailings and contaminate drinking water. Other trace elements are lead, cadmium, manganese, and nickel, all of which can have negative effects on the human body.
Burning of coal for power can also release mercury into the air, which also bioaccumulates in freshwater fish. Consumption of mercury can impair your hearing, vision, and speech, and cause severe damage to the brain, kidneys, and lungs.
The majority of the mines in Virginia are located in southwestern Virginia, near the border of West Virginia and Kentucky, along the Appalachian Mountains. The residents of this area deal with the “fallout” of the mining industry. Tazewell, VA, a town in of approximately 7,094 residents, is one example. According to the EPA, over 60% of the streams in this area are impaired. An official at the Virginia Department of Health Office of Drinking Water stated that all the drinking water in Tazewell County is piped in from sources uncontaminated by the coal industry.
If there are any health implications of the impaired water, they are isolated to those that have private wells.
Unfortunately, most are unaware of the symptoms associated with drinking contaminated water so many incidences go unreported. With only 50 people per square mile in Tazewell and surrounding areas, medical and environmental personnel are stretched thin. As such, there is a definite need for local stream monitoring efforts and community education about contamination-related symptoms to watch out for.
Mine Pollution: Cyanide
by Katherine Fite
Virginia was one of the first states to put gold mining on the map in 1792 when the first documented traces of gold were discovered near the Rappahannock River. For nearly a century and a half, from 1804 to 1947, gold mining flourished in Virginia. Virginia gold mining sites and prospective locations are located through out the state; covering over 15 counties. The heaviest concentrations of gold mines were located in the “gold-pyrite” belt, a 140-mile stretch of mines that runs down central Virginia from Fairfax county to Buckingham county. The California gold rush in the mid 1800’s led to a dramatic decline in Virginia mining and production eventually stopped in 1947. However, gold mining is still a larger part of the United States mining industry. In 2011 the US contributed to 8.8% of the worlds total gold production.
Mining generates a significant amount of waste and releases toxic substances into the surrounding environment. In fact, the mining industry is one of the United Sates largest producers of toxic substances. Almost every step of the mining process, from removal of rock material, to mining to milling, produces waste and toxic chemicals. For example, chemical toxicants are used in the milling process to extract as much mineral as possible from the ore. One such chemical is cyanide; used for the extraction of gold from metal ores. During a process called cyanidation, cyanide salts are mixed with water and crushed ore containing gold. The cyanide, which has a strong affinity to gold ions, binds to the gold to extract it from rock.
In many cases, waste produced from the process contains residual amounts of cyanide, which can be found in tailings (a sludge-like mixture of mining waste materials). These tailings can break through tailing dams and contaminate the surrounding environment and leach into the ground. Although the residual cyanide usually breaks down to less toxic harmful substances in the environment, the resulting compounds can still be proven toxic to wildlife. Aquatic species are especially susceptible to cyanide exposure and adverse health effects. Cyanide in water can cause problems with swimming and reproductive system issues. In addition, respiratory problems can arise along with thyroid gland disturbances, growth irregularities and even death.
Although some of residual cyanide in tailings does get naturally broken down, there still remains a significant amount of cyanide that is unaccounted for. In addition, cyanides can readily react with other elements and form hundreds of chemical compounds. Both of these facts make cyanide waste a concern to human health.
South Africa: Mining for Economy,
but Destroying Communities
by Jason Zheng
Acid mine drainage (also
sometimes referred to as acid rock drainage) is a well-understood process2 and
arises primarily when the mineral pyrite (‘fool’s gold’) comes into contact
with oxygenated water. The pyrite undergoes oxidation in a two-stage process,
the first producing sulfuric acid and ferrous sulfate and the second orange-red
ferric hydroxide and more sulfuric acid. Pyrite is a common minor constituent
in many mineral deposits and is associated with our coal (it is the main host
of sulfur in coal, the source of acid rain) and the gold deposits of the
Witwatersrand Basin. During normal weathering of these mineral deposits, acid
is produced but at a very slow rate, so slow that natural neutralization
processes readily remove the acidity.
Since the discovery of gold in
1886, mining has taken place in three underground basins, East, Central and
West Rand, in the Witwatersrand area in the Province of Gauteng. Gold was the
driving force of the economic growth in South Africa for many years. During
this time the more than 120 mines would have been required to pump out the
water that had entered the mines in order to allow for safe mining conditions.
As the mine’s minerals became exhausted, they became abandoned, thus causing
the voids of the mine to be filled with water.
As the water levels in the mine
voids rise, it increases the risks of seismic activity, contaminate shallow
aquifers, and geotechnical impacts (i.e. such as sinkhole formation). The rise
of underground mine water level can cause negative socio-economic factors. This
also means potential flooding of the Gold Reef City underground museum and the
possible destroying the remaining gold reserves. Once the AMD reaches the
surface, it flows down to wetlands, streams and rivers, and destroying aquatic
The Inter-Ministerial Committee
(IMC) on AMD is made up of the Ministers of Mineral Resources, Water and
Environmental Affairs, Science and Technology and the Minister in the
Presidency: National Planning Commission directed that a Team of Experts
investigate solutions to the AMD related challenges on the Gauteng gold mines.
Taking affirmative actions
against AMD in South Africa is not only a step to conserve the ecology, it is
also meant to protect the vulnerable communities that rely on the natural
resources. But we also have to say that if were to reduce footprints in the
mining industries, the county’s wealth and economy may take a toll. After all,
the mining industry played a large role in economic growth. The actions that
are needed to be taken, also fall upon how effectively the Government is able
to communicate to their people, coordination of their domestic and