Air Pollution from Coal:
3,700,000 tons of carbon dioxide (CO2), the primary human cause of global warming--as much carbon dioxide as cutting down 161 million trees. 10,000 tons of sulfur dioxide (SO2), which causes acid rain that damages forests, lakes, and buildings, and forms small airborne particles that can penetrate deep into lungs. 500 tons of small airborne particles, which can cause chronic bronchitis, aggravated asthma, and premature death, as well as haze obstructing visibility. 10,200 tons of nitrogen oxide (NOx), as much as would be emitted by half a million late-model cars. NOx leads to formation of ozone (smog) which inflames the lungs, burning through lung tissue making people more susceptible to respiratory illness. 720 tons of carbon monoxide (CO), which causes headaches and place additional stress on people with heart disease. 220 tons of hydrocarbons, volatile organic compounds (VOC), which form ozone. 170 pounds of mercury, where just 1/70th of a teaspoon deposited on a 25-acre lake can make the fish unsafe to eat. 225 pounds of arsenic, which will cause cancer in one out of 100 people who drink water containing 50 parts per billion. 114 pounds of lead, 4 pounds of cadmium, other toxic heavy metals, and trace amounts of uranium.
Waste generated:
Solid wasteWaste created by a typical 500-megawatt coal plant includes more than 125,000 tons of ash and 193,000 tons of sludge from the smokestack scrubber each year. Nationally, more than 75% of this waste is disposed of in unlined, unmonitored onsite landfills and surface impoundments.
Toxic substances in the waste -- including arsenic, mercury, chromium, and cadmium -- can contaminate drinking water supplies and damage vital human organs and the nervous system. One study found that one out of every 100 children who drink groundwater contaminated with arsenic from coal power plant wastes were at risk of developing cancer. Ecosystems too have been damaged -- sometimes severely or permanently -- by the disposal of coal plant waste.
Cooling water discharge
Once the 2.2 billion gallons of water have cycled through the coal-fired power plant, they are released back into the lake, river, or ocean. This water is hotter (by up to 20-25° F) than the water that receives it. This "thermal pollution" can decrease fertility and increase heart rates in fish. Typically, power plants also add chlorine or other toxic chemicals to their cooling water to decrease algae growth. These chemicals are also discharged back into the environment.
Waste heat
Much of the heat produced from burning coal is wasted. A typical coal power plant uses only 33-35% of the coal's heat to produce electricity. The majority of the heat is released into the atmosphere or absorbed by the cooling water.
Environmental Impact:
Coal mining
About 60% of U.S. coal is stripped from the earth in surface mines; the rest comes from underground mines. Surface coal mining may dramatically alter the landscape. Coal companies throughout Appalachia often remove entire mountain tops to expose the coal below. The wastes are generally dumped in valleys and streams.
In West Virginia, more than 300,000 acres of hardwood forests (half the size of Rhode Island) and 1,000 miles of streams have been destroyed by this practice.
Underground mining is one of the most hazardous of occupations, killing and injuring many in accidents, and causing chronic health problems.
Coal transportation
A typical coal plant requires 40 railroad cars to supply 1.4 million tons in a year. That's 14,600 railroad cars a year.
Railroad locomotives, which rely on diesel fuel, emit nearly 1 million tons of nitrogen oxide (NOx) and 52,000 tons of coarse and small particles in the United States. Coal dust blowing from coal trains contributes particulate matter to the air.
Coal storage
Coal burned by power plants is typically stored onsite in uncovered piles. Dust blown from coal piles irritates the lungs and often settles on nearby houses and yards. Rainfall creates runoff from coal piles. This runoff contains pollutants that can contaminate land and water.
Water Use:
A typical 500-megawatt coal-fired power plant draws about 2.2 billion gallons of water each year from nearby water bodies, such as lakes, rivers, or oceans, to create steam for turning its turbines. This is enough water to support a city of approximately 250,000 people.
When this water is drawn into the power plant, 21 million fish eggs, fish larvae, and juvenile fish may also come along with it -- and that's the average for a single species in just one year. In addition, EPA estimates that up to 1.5 million adult fish a year may become trapped against the intake structures. Many of these fish are injured or die in the process.
No comments:
Post a Comment