“…Microbial suspensions are likely to exert a chlorine demand, making chlorine residual an effective water quality parameter for detecting microbial suspensions (Helbling and VanBriesen, 2008). Helbling and VanBriesen (2008) found that chlorine residual is a suitable indicator for bacterial intrusions in a DSS, although they found that fairly high bacterial concentrations of 10 5 CFU/ml, 10 4 CFU/ml, and 10 3 CFU/ml are required for Escherichia coli, Staphylococcus epidermidis, and Mycobacterium aurum, respectively, to incur a chlorine demand in the suspensions of these organisms.…”