AWWA WQTC62569

Secondary disinfection is the primary mitigation step used by utilities to protect waterquality by controlling microbiological growth in distribution systems. Presently, theUS Environmental Protection Agency (USEPA) requires that a residual of 0.2 mg/ L disinfectant be maintained at the entry pointof a distribution system (Federal Register document #52 FR 42199). Reports have shownthat microorganisms can survive in distribution systems despite the continuing presenceof disinfectants (e.g., Pryor et al., 2003; Chauret et al., 2001), therefore placing doubt onthe ability of a disinfectant residual to ensure microbial protection from events such asbreeches in distribution integrity. It has been shown that a residual of 0.2 mg/L limits thegrowth of heterotrophic bacteria in the distribution system. However, there is limited datathat can identify the appropriate amount of disinfectant required to inactivate knownpathogens in distribution systems such as E. coli.The focus of this project is to examine the anti-microbial resistance of E. coli in chlorinatedannular reactors (ARs) that were operated under conditions relevant to drinking waterdistribution systems. In addition, the potential synergies of ultraviolet (UV) treatment and chlorinationon E. coli in distribution systems were examined. For comparative purposes, ARscontaining cast iron and polycarbonate coupons were used to compare disinfectantefficacy on different pipe material. Includes 3 references, tables.

Product Details

Edition:

Vol. - No.

Published:

11/01/2005

Number of Pages:

5

File Size:

1 file