AP Environmental Science

Case Studies---Water Pollution and Distribution

Aral Sea--In the 1970s the Amu Day’ya and Syr Dar’ya Rivers in Kazakhstan were diverted (primarily for irrigation water) from emptying into the Aral Sea. From that time, the Aral Sea has lost two-thirds its volume. Take a look at this website which chronicles the desertification of the Aral Sea through satellite imagery. http://edcwww.cr.usgs.gov/earthshots/slow/Aral/Aral

Aswan High Dam, Egypt---In the middle of the arid Egyptian desert lies one of the largest embankment dams in the world. It is called the Aswan High Dam, or Saad el Aali in Arabic, and it captures the mighty Nile River in the world's third largest reservoir, Lake Nasser. Before the dam was built, the Nile River overflowed its banks once a year and deposited four million tons of nutrient-rich silt on the valley floor, making Egypt's otherwise dry land productive and fertile. But there were some years when the river did not rise at all, causing widespread drought and famine. In 1952, Egyptian president Gamal Abdal-Nasser pledged to control his country's annual flood with a giant new dam across the Nile River. His plan worked.

The Aswan High Dam captures floodwater during rainy seasons and releases the water during times of drought. The water that is available is only half of what was expected due to evaporation and losses due to seepage in unlined canals. The dam also generates enormous amounts of electric power -- more than 10 billion kilowatt-hours every year. That's enough electricity to power one million color televisions for 20 years! Unfortunately, the dam has also produced several negative side effects. In order to build the dam, 90,000 Egyptian peasants had to move. To make matters worse, the rich silt that normally fertilized the dry desert land during annual floods is now stuck at the bottom of Lake Nasser! Farmers have been forced to use about one million tons of artificial fertilizers. Nutrients were also depleted in the Mediterranean causing a decline in certain fish catches. Finally, the proliferation of snails caused an epidemic of shictosomiasis, in some areas up to 80% of the people are infected.

Bangladesh--In the 1960s, thousands of wells were dug in Bangladesh and West Bengal, India by foreign governments and humanitarian organizations in an effort to supply freshwater to the population. Shortly thereafter arsenic poisoning began to appear in the population, and as many as 200 million people showed signs. Arsenic compounds from the soil are apparently leaching into the groundwater.

Chesapeake Bay, Maryland---Sediments in the Chesapeake Bay have shown the presence of bacteria that are producing methylated tin.

Colorado River Basin---Diversion of water from the Colorado River has led to disputed between California, Arizona, and Mexico over water rights. Glen Canyon and Boulder Dam also trap large quantities of silt (10 million metric tons per year). Farm irrigation has resulted in high levels of sodium chloride (salinization) in the alkaline soil. Sodium chloride incorporates into agricultural run-off that eventually ends up in the Colorado River. Millions of hectares of valuable farmland are now useless due to salt build-up in Colorado River water.

James Bay Project, Canada---Diversion of three major rivers into the Hudson Bay to generate electric power has resulted in massive flooding of lands that were used by the native Cree Nation. In addition, mercury has leached out of rocks and into the water with nearby residents showing signs of mercury poisoning. Ten thousand caribou drowned during migration.

Mono Lake---One casualty of the enterprise of bringing water to Los Angeles has been Mono Lake in California. As the Los Angeles Department of Water and Power diverted water from the tributaries that fed Mono Lake to provide water for LA, the salinity of the lake increased and its water level dropped. For more information about Mono Lake, visit the following website http://www.monolake.org/naturalhistory/index.html

Ogallala Aquifer, United States----One important source of water for agriculture in the United States, the Ogallala Aquifer, has been a cause of concern because it has been significantly depleted in some areas, particularly Texas. The Ogallala or High Plains aquifer lies under states from South Dakota to Texas and is the primary source of water in this region for irrigation. See the U.S. Geological Survey's page for more information. http://ne.water.usgs.gov/html/hpactivities.htm

Three Gorges Dam----At the time of its founding in 1949, the People’s Republic of China did not have any large reservoirs and only 40 small hydroelectric stations. By 1985, centrally planned projects to generate electricity through hydropower, increase irrigation coverage, and control flooding had resulted in the construction of more than 80,000 reservoirs and 70,000 hydroelectric stations. The world’s largest hydroelectric dam is being built at the Three Gorges on the Yangtze River in China, the entire project, to be completed in 2009, has required the Chinese government to relocate an estimated 1.2 million people. Worldwide estimates are that 30 million to 60 million people have been forcibly moved from their homes to make way for major dam and reservoir projects. These “reservoir refuges” are frequently poor and politically powerless; many are from indigenous groups or ethnic minorities. The experience of more than 50 years of large dam building shows that the displaced are generally worse off after resettlement, and more often than not they are left economically, culturally, and emotionally devastated.

Case Studies---Pollution and Hazardous Wastes

Bhopal, India---In the early hours if December 8, 1984, gas leaked from a tank of methyl isocyanate at a plant in Bhopal, India, owned and operated by Union Carbide Corporation. The Indian government reported that approximately 3800 people dies, 40 people experienced paramagnet total disability and 2680 people experiences partial disability. DDT---The first synthesized chlorinated pesticide was discovered in 1939 by Paul Muller (Nobel Prize 1944 for its discovery). It appeared to have low toxicity and was broad spectrum. It did not break down so t did not have to be reapplied often. DDT was insoluble in water and was relatively inexpensive. Crop production increased, mosquito populations decreased. In 1962, Rachel Carson published Silent Spring, which made the connection between DDT and non-target organisms by direct toxicity and indirect toxicity (persistent in the environment)---biomagnification (an increase in concentration up the food chain) and bioaccumulation (the tendency for the compound to accumulate in fatty tissue). In Long Islands Sound, concentration of DDT in the water was measured at 3 parts per trillion. At the top of the food chain, it had accumulated to 25 parts per million in fish-eating birds (a 10 million times increase). Furthermore, studies showed reduction in calcium in eggshells, which caused eggs to crack, destroying chicks. Eggshell thinning was linked to a decline in the population of bald eagles and peregrine falcons. DDT was also showing up in Eskimos, seals, and human breast milk. It was banned in the US in 1972. DDT is currently being manufactured in Indonesia.

Donora, Pennsylvania----Between Oct. 26 and 31, 1948, 20 people were asphyxiated and over 7,000 were hospitalized or became ill as the result of severe air pollution over Donora, Washington County, the Monongahela River town of 14,000. The causes of the incident are difficult to identify conclusively, nevertheless, there are several obvious possibilities. Residents, such as Mrs. Lois Bainbridge, who wrote to Governor James T. Duff about the situation, stated that people in the area had complained for years abut the industrial pollutants that “eat the paint off your houses" and prevents fish from living in the river. Indeed, an investigation supervised by the director of the state government's Bureau of Industrial Hygiene revealed an extraordinarily high level of sulfur dioxide, soluble sulfur, and fluorides in the air on October 30 and 31. According to the agency's report and complaints by residents, such contamination of the atmosphere was caused by the zinc smelting plant, steel mills' open hearth furnaces, a sulfuric acid plant, with slag dumps, coal burning steam locomotives, and river boats also contributing to the problem. An unusually dense fog may have been held in the valley by the surrounding hills (thermal inversion).

The investigation of this incident by state and federal health officials resulted in the first meaningful federal and state laws to control air pollution and marked the beginning of modern efforts to assess and deal with the health threats from air pollution.

Living Machine---A Living Machine (capital letters, it's a patented invention) is a series of tanks teeming with live plants, trees, grasses and algae, koi and goldfish, tiny freshwater shrimp, snails, and a diversity of microorganisms and bacteria. Each tank is a different mini-ecosystem designed to eat or break down waste. The process takes about four days to turn mucky water crystal clear. It is chemical-free, odor-free (with the exception perhaps of the sweet fragrance of flowers), and, compared to conventional waste treatment, it costs less financially and ecologically. Living Machines are site-specific, biological solutions that re-route waste streams into resources. To find out more about Living Machines, visit http://www.audubon.org/local/sanctuary/corkscrew/Information/LivingMachine.html

London Fog---Most of the “fog” in London was pollution caused by local factories and open coal fires used to heat houses. In the early 1950s, London had also just replaced its electric tramcars with diesel buses. In 1952, a four-day London fog, trapped by the surrounding hills and stagnant warm air mass above it (thermal inversion), killed roughly 4000 Londoners and was the beginning of the air pollution reform in the United Kingdom. Parliament enacted the Clean Air act in1956, effectively reducing the burning of coal.

MTBE—Reformulated Gasoline---The Clean Air Act (1990) required 17 of the nations’ urban centers with the worst air quality to add 2% oxygenates to gasoline. Oxygenates reduce VOCs and other toxic emissions from gasoline. The most common reduction oxygenated are MTBE (methyl tertiary butyl ether) and ethanol (ethyl alcohol or EtOH). Since its addition to gasoline, issues of health concerns and groundwater contamination from leaking gasoline tanks have caused states to request the phasing out of MTBE. An alternative to MTBE is ethanol, which is produced from corn. Proponents of ethanol point out that ethanol does not have major pollution issues and will help the agricultural economy. Critics of ethanol contend that massive government subsidies are required. It is estimated by Common Cause that federal subsidies for ethanol production are close to $7 billion. Research is showing that decreases in ground-level ozone from oxygenate use may not be as optimistic as originally thought.

Exxon Valdez 1989-- The Alaska oil pipeline had always been a controversial project. It required a special act of Congress to allow its construction to begin. The oil shocks of the mid-1970s added impetus to the construction, but in March of 1989, the worst fears of its opponents came to pass when the super tanker Exxon Valdez ran aground. At 9:12 pm on March 22, the Exxon Valdez under the command of Captain Joseph Hazelwood left the Alyeska terminal and headed out of Prince William Sound. As is normal in such waters she carried a harbor pilot who was familiar with the waters, but dropped the pilot at 11:24 pm. The ship then proceeded into the Valdez Arm. Like highways on land, the channel had specified lanes for inbound and outbound traffic. The Exxon Valdez requested and received permission to move from the outbound to the inbound lane to avoid ice that was in the outbound part of the channel. At this point, the third mate was in command of the bridge and the captain had gone below to complete some paperwork. The ship was now heading directly for Bligh Reef. If all had gone according to plan, the ship would have made a turn that would have brought it back into the Valdez Arm and avoided the reef. Unfortunately, the ship failed to make the turn in time and at approximately 12:11 on March 24; she ran aground on the reef and began leaking her cargo of crude oil. Before the leak was stopped she had dumped eleven million gallons of crude into the sound.

Alyeska's response to the spill was less than spectacular. Its own plan called for it to respond to such an emergency within two to five hours. The first Alyeska's crews weren't on the scene for nearly fifteen hours. When they did arrive, they were without much vital equipment. They had no containment booms, and no oil recovery barge. As the investigation into the accident progressed, it became clear that there were many factors that led to the accident or made it worse. There were allegations that Captain Hazelwood was under the influence of alcohol and the third mate was unqualified to pilot in Prince William Sound. Exxon was cited for the cost cutting measure of reducing tanker crews from twenty to sixteen, which increased crew fatigue. Alyeska's response, also the result of cost cutting measures, was also cited as inadequate. Regulators were also shown to have failed. Throughout the 1980s, the Environmental Protection Agency had been hampered by political controversy at the top and inadequate funding which caused it to abrogate much of its responsibility to the State of Alaska. The state obtained a large portion of its revenue from the oil industry so they were hesitant to do anything that might jeopardize those funds. The Coast Guard had also been subject to tighter budgets and was forced to concentrate much of its resources to southern waters to fight the war on drugs.

It is estimated that 1000 miles of shoreline were affected. At best, only 15% of oil from a spill can be recovered. Exxon initially spent $2.2 billion on the cleanup, $1 billion in fines, and $5 billion in punitive damages. The total cost of the spill is estimated to be $8.5 billion. Hot water high-pressure sprays used to clean rocks destroyed habitats. The accident may have been prevented if the ship had a double-hull. By 2015, all new tankers must have a double hull. Go the link below to get some pictures of the spill Images from the Exxon Valdez Spill

Oil Spill Facts Prince William Sound: An Ecosystem in Transition The Exxon Valdez Oilspill

Bet Trang, Cambodia, 1999---A Taiwan plastic factory shipped 3000 tons of toxic waste including mercury to Bet Trang, Cambodia. Bribes were involved. Villagers used wastes for personal use. Villagers became sick and some died.

Khian Sea, 1986---The city of Philadelphia needed to get rid of 14,000 tons of toxic incinerator ash. It had previously dumped the waste in a landfill in NJ. New Jersey refused to accept the waste and it was loaded onto a ship, the Khian Sea, which roamed the world for two years looking for someplace to accept the load. The waste “mysteriously” disappeared at sea.

Love Canal, New York, 1970s---More than 20,000 tons of toxic wastes by Hooker Chemical were buried here during the late 1940s. The toxic wastes were covered with soil. Hooker Chemical sold the land to the Niagara Board of Education for $1. In the 1970s, the area became a housing development. Serious health problems arose including miscarriages, birth defects and cancers. More than 80 different hazardous chemicals were released into groundwater, coming up from the soil, seeping into basements and so on. The Love Canal tragedy led to the passage of the Resource Conservation and Recovery Act (RCRA), Comprehensive Response Compensation, and Liability Act (CERCLA). Almost 1000 families were relocated at a cost close to $300 million. Agent Orange—Agent Orange was used as a defoliant during the Vietnam War. 250,000 veterans may have been affected. Agent Orange was the code name for a herbicide developed for the military, primarily for use in tropical climates. Although the genesis of the product goes back to the 1940's, serious testing for military applications did not begin until the early 1960's. The purpose of the product was to deny an enemy cover and concealment in dense terrain by defoliating trees and shrubbery where the enemy could hide. The product "Agent Orange" (a code name for the orange band that was used to mark the storage drums) was principally effective against broad-leaf foliage, such as the dense jungle-like terrain found in Southeast Asia. The product was tested in Vietnam in the early 1960's, and brought into ever widening use during the height of the war (1967- 68). Use was diminished and eventually discontinued in 1971. Agent Orange was a 50-50 mix of two chemicals, known conventionally as 2,4, D and 2,4,5,T. The combined product was mixed with kerosene or diesel fuel and dispersed by aircraft, vehicle, and hand spraying. An estimated 19 million gallons of Agent Orange were used in South Vietnam during the war. The earliest health concerns about Agent Orange were about the product's contamination with TCDD, or dioxin. TCDD is one of a family of dioxins, some found in nature, and are cousins of the dibenzofurans and PCB's.

The TCDD found in Agent Orange is thought to be harmful to man. In laboratory tests on animals, TCDD has caused a wide variety of diseases, many of them fatal. TCDD is not found in nature, but rather is a man-made and always unwanted byproduct of the chemical manufacturing process. The Agent Orange used in Vietnam was later found to be extremely contaminated with TCDD.

Minamata---A vinyl chloride manufacturing plant on a Japanese island allowed mercury to be discharged into the bay. Mercury was converted into methylmercury and biomagnified through the food chain. Human symptoms varied but included nervous system damage, blurred vision, and loss of muscular coordination. It was determined that a threshold amount of methylmercury was required for symptoms to appear.

Times Beach, Missouri---Oil sprayed on roadways contained dioxin. The town was evacuated and destroyed by the US government because dioxin disrupts the endocrine, immune, and reproductive systems.