Introduction. Most people recover without antibiotics or other specific treatment in 5-10 days. There is no evidence that antibiotics improve the course of disease, and it is thought that treatment with some antibiotics may precipitate kidney complications. Antidiarrheal agents, such as loperamide (Imodium), should also be avoided. The most common methods of treating water contaminated with E. coli is by using chlorine, ultra-violet light, or ozone, all of which act to kill or inactivate E. coli. Systems, using surface water sources, are required to disinfect to ensure that all bacterial contamination is inactivated, such as E. coli. Systems using ground water sources are not required to disinfect, although many of them do.
Purpose of the study. According to EPA regulations, a system that operates at least 60 days per year, and serves 25 people or more or has 15 or more service connections, is regulated as a public water system under the Safe Drinking Water Act (SDWA). If a system is not a public water system as defined by EPA’s regulations, it is not regulated under the SDWA, although it may be regulated by state or local authorities.
Materials and methods. Under the SDWA, EPA requires public water systems to monitor for coliform bacteria, United States Public Health Services (USPHS) to establish and enforce regulations
Results and discussion. Systems analyze first for total coliform, because this test is faster to produce results. Any time that a sample is positive for total coliform, the same sample must be analyzed for either fecal coliform or E. coli. Both are indicators of contamination with animal waste or human sewage. The largest public water systems (serving millions of people) must take at least 480 samples per month. Smaller systems must take at least five samples a month, unless the state has conducted a sanitary survey - a survey in which a state inspector examines system components and ensures they will protect public health - at the system within the last five years [1-2].
Viruses are the 2nd most problematic pathogen, behind protozoa. As with protozoa, most waterborne viral diseases don't present a lethal hazard to a healthy adult. Waterborne pathogenic viruses range in size from 0.020-0.030 fim, and are too small to be filtered out by a mechanical filter. All waterborne enteric viruses affecting humans occur solely in humans, thus animal waste doesn't present much of a viral threat. At the present viruses don't present a major hazard to people drinking surface water in the U.S., but this could change in a survival situation as the level of human sanitation is reduced. Viruses do tend to show up even in remote areas, so a case can be made for eliminating them now. ARDS
When the objective of water treatment is to provide drinking water, then we need to select technologies that are not only the best available, but those that will meet local and national quality standards. The primary goals of a water treatment plant for over a century have remained practically the same: ' namely to produce water that is biologically and chemically safe, is appealing to the consumer, and is noncorrosive and nonscaling. [2-5].
For inorganic contaminants
The growth of community water supply systems in the United States started in the early 1800s. By 1860, over 400, and by the turn of the century over 3000 major water systems had been built to serve major cities and towns. Many older plants were equipped with slow sand filters. In the mid 1890s, the Louisville Water Company introduced the technologies of coagulation with rapid sand filtration.
The first application of chlorine in potable water was introduced in the 1830s for taste and odor control, at that time diseases were thought to be spread by odors. It was not until the 1890s and the advent of the germ theory of disease that the importance of disinfection in potable water was understood. Chlorination was first introduced on a practical scale in 1908 and then became a common practice.
Federal authority to establish standards for drinking water systems originated with the enactment by Congress in 1883 of the Interstate Quarantine Act, which authorized the Director of the United States Public Health Services (USPHS) to establish and enforce regulations to prevent the introduction, transmission, or spread of communicable diseases.
Conclusions. Today, plant design has become very complex from discovery of seemingly innumerable chemical substances, the multiplying of regulations, and " trying to satisfy more discriminating palates. In addition to the basics, designers must now keep in mind all manner of legal mandates, as well as public concerns and en-vironmental considerations, to provide an initial prospective of water works engineering planning, design, and operation.
- Climate Change 2001. Synthesis report. (Cambrige University Press, UK, 2003).
- G. I. Marchuk, Mathematical Modelling in Environmental Problems (Nauka, Moscow 1982).
- G. I. Marchuk, Adjoint Equations and Analysis of Complex Systems (Kluwer Academic Publishers, Dordrecht, 1995).
- V. V. Penenko, Methods of Numerical Modelling of Atmospheric Processes (Gidrometeoizdat, Leningrad, 1981).
- V. V. Penenko and A. E. Alojan. Models and methods for environment protection problems (Nauka, Novosibirsk, 1985).