AWWA ACE68638

This powerpoint presentation begins by stating the drivers behind this research that include: distribution systems identified as major security challenge by AWWA; drinking water remains a relatively simple target for dissemination of biothreat agents; and, disinfection data is needed to assist response and remediation efforts. Topics covered by the presentation include: efficacy of chlorine and monochloramine -- planktonic testing; persistence of Bacillus anthracis spores in a model biofilm; efficacy of chlorine and chloramine -- spores associated with a model drinking water biofilm; ultraviolet possibilities; and, future research needs. Presentation conclusions indicate that: spores will persist on surface with biofilm (>42 days); uncertain if growth occurring within biofilm; even an immature biofilm can decrease disinfectant efficacy 3 to 5 fold; and, CT values may need to be re-visited to consider biofilm shedding and spore clumping (are planktonic cells truly planktonic?). Includes tables, figures.