Nancy J. Schmitt
Water may be contaminated by many different substances. The main categories are microorganisms or microbes, organic chemicals, inorganic chemicals, disinfectants, disinfection byproducts and radionuclides.
17
Microbes tested in drinking water include Cryptosporidium, Giardia lamblia, viruses from human and animal waste and legionella are found naturally in water, but multiply in heating systems.
18
Organic Chemicals tested in drinking water include acryllamide, alachlor, atrazine, benzene, carbon tetrachloride, chlordane, dioxin, polychlorinated biphenyls(PCB), toluene, and vinyl chloride. These chemicals and others in this organic chemicals are generally from runoff from chemical, plastic, degreasing, and textile factories, and application of herbicides and insecticides.
19
Disinfectants such as chlorine, chloramine and chlorine dioxide are also tested in drinking water and in some cases byproducts of the process used to control microbes.
20
Disinfection byproducts tested in drinking water include bromate, chlorite, haloacetic acids, and total trihalomethanes which are byproducts of the use of disinfectants in the water to control microbes.
21
Inorganic Chemicals tested for are antimony, arsenic, asbestos, barium, beryllyum, cadmium, chromium, copper, fluoride, lead, mercury, nitrate, nitrateselenium, and thallium. These inorganic chemicals get into the water supply by leaching from ore-producing sites, fertilizer, plastic and metal factories, runoff from croplands and landfills, and erosion of natural deposits.
22
Radionuclides that are monitored include alpha and beta particle, radium 226 and 228 and uranium which come primarily from erosion of natural deposits.
23
Some of the potentially harmful chemicals occur naturally in many areas and find their way into our water. At certain levels the elements are beneficial and necessary for healthy life, but at greater amounts can be harmful and cause illness. An example of this would be iron. Other chemicals are produced from the cleaning or sanitizing process where chlorine is used. Chlorine itself is dangerous to people, yet is used to kill germs or microbes. One of the outcomes is that chlorinated water is in most cases safer, because it contains fewer germs or microbes, but sometimes compounds created in the chlorination process are also harmful to humans.
24
Chemicals like MTBE, which have been used in the United States as a gasoline additive to reduce automobile emissions from carbon monoxide do not yet have a standard maximum level, MTBE is being studied since there have been reports of it being detected in the surface water and ground water.
25
Uranium has been found in the water at two Madison, Connecticut schools at 110 microgram per liter of water; well above the EPA thresholds of 30 microgram per liter for homes. There currently is no set standard for schools, but common sense dictates that there should not be allowed more uranium at schools than at homes. The uranium is in water from wells that were drilled several decades ago.
26
Other than byproducts of the drug manufacturing process, there do not appear to be many pharmaceuticals currently on the monitoring list.