The presence of bacteria in water after regrowth

The processes used for producing potable water are not intended to produce bacteria-free water; rather, they are concerned with removing microorganisms that are a potential health threat and making water aesthetically pleasing. The types of processes used to treat water appear to have relatively little effect on the types of bacteria that can pass through the treatment process, although disinfection with oxidizing disinfectants will tend to remove vegetative bacteria, whereas bacterial spores may well be unaffected. It is well understood that there are many factors that affect an organism's susceptibility to chlorine disinfection, and one of the major factors appears to be the degree of metabolic activity. Organisms that have grown in low-nutrient systems or have been " starved " tend to be considerably more resistant to disinfection than those grown under laboratory conditions in nutrient-rich media. Thus, caution must be applied in