City Changes its Disinfection Process for Drinking Water (click title to entry - thank you)
July 22, 2011
The city of Greensboro issued the following news release:
Starting the week of July 25, The City of Greensboro Water Resources Department in cooperation with Archdale, Burlington, High Point, Jamestown, Randleman, Reidsville, and the Piedmont Triad Regional Water Authority will convert its water system disinfectant from free chlorine to chloramines. The change will occur to comply with new, more stringent drinking water regulations.
Chloramine disinfectant is a chemical combination of chlorine and ammonia used together to eliminate bacteria from drinking water. The use of chloramines will lower the level of disinfection byproducts (DBPs) that are produced when chlorine reacts with organic matter in source water. The change will also reduce the taste and odor concerns associated with chlorine disinfection methods.
Chloramines are an effective disinfectant used by many water utilities across the United States. While chloramines are safe for drinking and all other everyday water uses, kidney dialysis patients, fish and amphibian owners, and specialized industries should take special care....
Chloramine has to be limited to 4ppm in water consumed through municipal systems.
WHY?
Because unlike Free Chlorine which metabolizes quickly, chloramine can have some very nasty outcomes. Does anyone ever expect at some point there would be an INCORRECT dosing into a water supply? What would happen if it were Free Chlorine? Not a thing. But, chloramine has issues. Patients on kidney dialysis can't be exposed to it through their kidney dialysis machines.
Old Housing. Anyone familiar with Greensboro and the surrounding area knows that there is much more old housing than new housing. In order to get the chloramine out of the water from the tap one has to perform a dousing of the water with free chlorine and about 24 hours of ultraviolet exposure from the sun in order to remove the lousy stuff.
Chloramine has to be limited to 4ppm in water consumed through municipal systems. WHY?
Because unlike Free Chlorine which metabolizes quickly, chloramine can have some very nasty outcomes. Does anyone ever expect at some point there would be an INCORRECT dosing into a water supply? What would happen if it were Free Chlorine? Not a thing. But, chloramine has issues. Patients on kidney dialysis can't be exposed to it through their kidney dialysis machines.
Adding chloramine to the water supply can increase exposure to lead in drinking water, especially in areas with older housing; this exposure can result in increased lead levels in the bloodstream and can pose a significant health risk.
There is also evidence that exposure to chloramine can contribute to respiratory problems, including astham among swimmers. Respiratory problems related to chloramine exposure are common and prevalent among competitive swimmers.
Chloramine use, together with chlorine dioxide, ozone and ultraviolet has been described as a public health concern and an example of the outcome of poorly implemented environmental regulation. These methods of disinfection decrease the formation of regulated by-products, which has led to their widespread use. However, they can increase the formation of a number of unregulated cytotoxic and genotoxic byproducts, some of which pose greater health risks than the regulated chemicals, causing such diseases as cancer, kidney disease, thyroid damage, and birth defects.
Old Housing. Anyone familiar with Greensboro and the surrounding area knows that there is much more old housing than new housing. In order to get the chloramine out of the water from the tap one has to perform a dousing of the water with free chlorine and about 24 hours of ultraviolet exposure from the sun in order to remove the lousy stuff.
Chloramine can be removed from tap water by treatment with superchlorination (10 ppm or more of free chlorine, such as from a dose of sodium hypochlorite bleach or pool sanitizer) while maintaining a pH of about 7 (such as from a dose of hydrochloric acid). Hypochlorous acid from the free chlorine strips the ammonia from the chloramine, and the ammonia outgasses from the surface of the bulk water. This process takes about 24 hours for normal tap water concentrations of a few ppm of chloramine. Residual free chlorine can then be removed by exposure to bright sunlight for about 4 hours.
