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![]() Bill Kearney wrote: I drink my tap water every day! It has the same chlorine as bleach has in it. Err, no it doesn't and certainly in nowhere near the same concentration. But hey, go ahead and give drinking it a try. Are you REALLY trying to say that my county water doesn't have chlorine in it??? Really, now, are you? He http://www.c3.org/chlorines_everyday_uses/before.html Which, in part states: Just as water is essential to life, chlorine is essential to safe water. Public health officials overwhelmingly agree: In a 1992 survey of public health officials, 92 percent agreed that chlorine is crucial to eliminating waterborne diseases, and 87 percent said they view chlorine as the safest way to assure quality drinking water. Experts also agree that chlorine's introduction early this century into the U.S. drinking water supply is one of history's great public health advances. Safe, chlorinated water has played a key role in: a 50 percent-plus increase in life expectancy, from about 45 years in the early 1900s to about 76 years at present; a dramatic decline in infant mortality rates; and the virtual elimination of cholera, typhoid fever, dysentery and gastroenteritis, as well as many other waterborne diseases which once killed tens of thousands of Americans. Or this: A Water Treatment Primer Water treatment practices vary in the United States, but there are generally accepted basic techniques. Source water quality predicates the kind of treatment required to provide safe water. Therefore, protecting source water quality is a primary goal. The treatment choice depends on a number of factors that are site specific and for which adjustments must be made depending on raw water quality. Source water quality and turbidity (particulate matter) levels, water temperature and pH level, and incidence of pathogenic contaminants must be taken into account for treatment decision making. Conventional, sequential water treatment for surface water proceeds as follows: watershed protection program; pretreatment employing flocculation and sedimentation to remove turbidity, as well as the organic precursors that form by-products; filtration; disinfection at an appropriate concentration (C) for a prescribed time (T) (CT criteria) to destroy harmful organisms; and the addition of chlorine to maintain residual disinfection throughout the distribution system. There may also be a need for prechlorination or rechlorination during storage and/or distribution to ensure that an appropriate residual is maintained throughout the system. Table 1. Disinfection Practices in the USA Disinfectant Percentage* Chlorine gas 87.0 No ammonia 67.0 Ammonia added 20.0 Chlorine & hypochlorite 4.5 Chlorine & chlorine dioxide 3.0 Chlorine & chlorine dioxide & ammonia nitrogen 1.5 Hypochlorite 1.5 Chlorine & hypochlorite & ammonia nitrogen 0.75 Chlorine & chlorine dioxide & hypochlorite 0.37 98.6% use chlorine-based disinfectants Ozone 0.37 Other 0.75 * Percentage of facilities that disinfect Source: 1989-1990 AWWA Disinfection Committee Survey of Disinfection Practices Primary disinfection provides the appropriate CT to inactivate microbial pathogens. Disinfectants proven effective for this purpose include free chlorine, chlorine dioxide and ozone. Secondary disinfection ensures residual protection to control microorganism regrowth or recontamination during water storage and distribution. Either free chlorine or chlorine plus the addition of ammonia to form chloramine accomplishes this task. Because ozone quickly decomposes in water, a chlorine-based disinfectant must be added prior to distribution to provide this second level of protection. Need some more? Just let me know! By the way, I keep my pool chlorine level at 3 ppm, my drinking water here tests at 2 ppm |
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