“…Th e latter objective pertain s to m ain ten an ce of system pressu re, equ alization of dem an ds on su pply sou rces, redu ction in sizes or capacities of existin g m ain s, provision of water for n orm al dem an d, excess storage for peak dem an d an d fire su ppression , an d su pply of u n in terru pted water service du rin g power ou tages. [1][2][3][4][5][6][7] Th is policy m ean s th at water m ay rem ain in th e system for lon g periods of tim e. Lon g residen ce tim es can adversely affect th e qu ality of fin ish ed water in term s of redu ced disin fectan t residu als, in crease in DBPs, occu rren ce of n itrification , proliferation of bacteria, an d aesth etic degradation (taste, odor, an d appearan ce). Lon g residen ce tim es m ay h ave been ju stified in th e past becau se of th e absen ce of techn ology for evalu atin g su ch effects an d th e level of regu latory con trol.…”