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Contaminant candidate list viruses: evaluation of disinfection efficiency (collaborative project with AWWARF) - WT02039

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)
Time-Scale and Cost
From: 2005

To: 2008

Cost: £55,383
Contractor / Funded Organisations
AWWA Research Foundation
Environmental monitoring              
Environmental Protection              
Water quality monitoring              
Fields of Study
Water Quality