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Contaminant candidate list viruses: evaluation of disinfection efficiency (collaborative project with AWWARF) - WT02039
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Description
The Surface Water Treatment Rule (SWTR) regulations require a four log removal or inactivation of viruses in a treatment plant and a residual of 0.2 mg/L for at least four hours in the distribution system (10). More than 60 percent of treatment systems use chlorine as a disinfectant. Chloramine is used primarily as a secondary disinfectant to minimize disinfection byproduct (DPB) formation in drinking water and distribution systems. Typical chlorine doses at watertreatment plants are 0.2-2 mg/L. The efficiency of disinfection can be measured as "CT values," which is the product of the residual disinfection are based on a free chlorine residual.
The EPA Guidance Manual for Alternative Disinfections and Oxidants recommends a CT value of six to achive a 4-log inactivation of viruses using chloramine. Clearly the chloramines used as a primary disinfectant would be very difficult in practice. However, the use of chloramines following a primary disinfectant has gained some acceptance and has demonstrated to be effective for Cryptosporidium |
Project Documents
Executive Summary : Contaminant candidate list viruses: evaluation of disinfection effici
(19k)
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Time-Scale and Cost
From:
2005
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To:
2008
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Cost: £55,383 |
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Contractor / Funded Organisations
AWWA Research Foundation |
Keywords
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Fields of Study
Water Quality |