Clean Air Act Essays - Pollutants, Soil Contamination, Free Essays

Clean Air Act Essays - Pollutants, Soil Contamination, Free Essays Clean Air Act 1990, the federal Clean Air Act was passed to improve air quality in the United States. President Bush's proposed amendments to the Clean Air Act initially would have led to the introduction of alternative, non-petroleum fuels. The petroleum and oxygenate industries responded by offering a reformulated gasoline program as a substitute for most of the alternate fuel proposals. As a result, the amendments to the federal Clean Air Act adopted in 1990 required steps to achieve lower vehicle emissions, including programs to oxygenate and reformulate gasoline. Oxygenated gasoline is designed to increase the combustion efficiency of gasoline, thereby reducing carbon monoxide emissions. Since January 1995, the 1990 Clean Air Act Amendments require areas that have the most severe ozone pollution to use reformulated gasoline containing fuel oxygenates to improve air quality. Methyl Tertiary Butyl Ether is one of the most commonly used fuel oxygenates because it is produced in very large amounts from isobutylene, a waste product in the refining process. MTBE can be easily produced at the refinery, at a low cost, and can be transferred through existing pipelines once it has been blended with gasoline. In contrast to other gasoline additives used in the past, MTBE is a member of a class of chemical compounds, ethers, whose unique properties are enhanced solubility in water and chemical attraction to water molecules. These properties, along with widespread use of MTBE, have resulted in frequent detection of MTBE in samples of shallow groundwater from urban areas throughout the United States. MTBE moves quickly to shallow groundwater because it is not attached to soil particles, and is chemically attracted to water molecules. MTBE the potential to impact regional groundwater sources and may present a cumulative contamination hazard due to its mobility and apparent recalcitrance. The United States Geological Survey, in a paper presented to the American Chemical Society in San Francisco in April 1997, noted that MTBE can move from shallow to deeper aquifers with time. MTBE enters the environment, and eventually the groundwater, mainly from leaking underground fuel tanks and associated piping, but also from incomplete combustion in internal combustion engines, spilling and evaporation during transportation and refueling, and watercraft exhaust. Atmospheric precipitation may be another potential sourc e of MTBE in groundwater, because MTBE percolates easily through soil due to its small molecular size and solubility in water, allowing it to move rapidly into groundwater. The Environmental Protection Agency has classified MTBE as a possible human carcinogen, but no drinking-water regulation has been established for the compound. The Environmental Protection Agency has issued a drinking water advisory of 20- 40 micrograms per liter, based upon odor and taste thresholds, and to provide a large margin of safety from carcinogenic effects. Since February 1997, the California Department of Health Services has required public water suppliers to monitor their drinking water sources for MTBE. As of December 1997, about 23%of drinking water sources in California had been sampled for MTBE contamination. Of those sites tested, 33 or 1.3%, had detectable levels of MTBE. Of the contaminated sites tested, 36% had MTBE levels above the state's proposed drinking water standard. Some water systems only test every three years for volatile organic compounds, such as MTBE, so it will be the end of 2000 before all systems will have been tested. For MTBE, this frequency of impact to public drinking wells may not be a reliable indicator of future trends because it reflects a history of releases, including those involving gasoline formulations containing no or only low volumes of MTBE. It also appears that dissolved benzene plumes were of larger regulatory concern than MTBE in previous studies. Most studies have indicated that MTBE does not biodegrade easily under various environmental conditions. If a research investigation determines that a compound does not degrade, a half-life is not reported and the compound is classified as recalcitrant. MTBE is generally reported as recalcitrant, and there are no widely accepted estimates of the half-life. Investigators have reported that MTBE is recalcitrant in anaerobic laboratory studies including denitrifying conditions, sulfate-reducing conditions, methanogenic-reducing conditions, and anaerobic conditions in landfill-affected aquifer material, soils, and sludges. One 1995 result indicated there was no degradation of MTBE in an aerobic laboratory study after more

A Short Guide to Capitalization

A Short Guide to Capitalization A capital letter is the form of an alphabetical letter (such as A, B, C) used to begin a  proper noun  or the first word in a sentence. A capital letter is an uppercase letter in contrast to lower case. Verb: capitalize. Also known as  majuscule, uppercase, upper-case, block letter, and caps. In classical Greek and Latin writing, only capital letters (also called majuscules) were used. Examples and Observations By the sixth and seventh centuries the various letter forms we now use had been invented . . .. From the ninth century on all writing in the Latin alphabet, in whatever style or hand, used capital and small-letter pairs as we do now.(Thomas A. Sebeok, Current Trends in Linguistics, 1974)A capital is always used for the first letter of a sentence. It is a universal rule. But the same cannot be said for the capitalization of names or proper nouns. Style varies wildly betweenand even withinpublications such as national newspapers and magazines. Apply commonsense rules. All names of people and placesPeter Cook, Paraguay, Piccadilly Circustake capitals. All titles of specific works of artCitizen Kane, the Mona Lisa, Beethovens Fifth Symphony, Anna Kareninatake a capital. Languages and nationalitiesEnglish, the Frenchtake capitals. Institutionsthe Houses of Parliament, the White House, the Anglican Churchtake capitals. Days, months and formally defined periods of historyMonday, February, t he Middle Agestake capitals. . . .Words deriving from proper names usually take a capitalas Christian from Christ and Marxist from Marx. But some such words, known as eponyms, have come into everyday use and no longer take a capital.(Ned Halley, Dictionary of Modern English Grammar. Wordsworth, 2005) She laid the folded newspaper on the counter between us, and my eye caught the words DISASTER, FAILURE and CRASH.(Eva Figes, Nellys Version. Secker Warburg, 1977) Trends in Capitalization I am a poet: I distrust anything that starts with a capital letter and ends with a full stop (Antjie Krog)Times have changed since the days of medieval manuscripts with elaborate hand-illuminated capital letters, or Victorian documents in which not just proper names, but virtually all nouns, were given initial caps (a Tradition valiantly maintained to this day by Estate Agents). A look through newspaper archives would show greater use of capitals the further back you went. The tendency towards lowercase, which in part reflects a less formal, less deferential society, has been accelerated by the internet: some web companies, and many email users, have dispensed with capitals altogether.(David Marsh and Amelia Hodsdon, Guardian Style, 3rd ed. Guardian Books, 2010)If in doubt use lower case unless it looks absurd.(The Economist Style Guide. Profile Books, 2005) The Lighter Side of Capital Letters He believed in a door. He must find that door. The door was the way to . . . to . . .The Door was The Way.Good.Capital letters were always the best way of dealing with things you didnt have a good answer to.(Douglas Adams, Dirk Gentlys Holistic Detective Agency. Pocket Books, 1987) Carol Fisher: This is Scott ffolliott. Newspaperman, same as you. London correspondent. Mr. Haverstock, Mr. ffolliott.Scott ffolliott: With a double f.Johnny Jones: How do you do?Scott ffolliott: How do you do?Johnny Jones: I dont get the double f.Scott ffolliott: Theyre at the beginning, old boy. Both small fs.Johnny Jones: They cant be at the beginning.Scott ffolliott: One of my ancestors had his head chopped off by Henry VIII, and his wife dropped the capital letter to commemorate the occasion. There it is.Johnny Jones: How do you say it, like a stutter?Scott ffolliott: No, just straight fuh.(Laraine Day, George Sanders, and Joel McCrea in Foreign Correspondent, 1940)