E. coli are a type of bacteria which exists in large numbers within both the human and animal intestines. By analysising the water content for the concentration of E coli. we are able to determine directly, the amount of faecal contamination in the water (because when you poop, e. coli is contained in there also right?
). Basically this allows for environmentalists/w/e to treat the water accordingly, monitor it and determine whether it is healthy for exposure to humans. Thus, reducing both the spread and formation of infectious diseases created from faecal contamination, such as cholera (where you get "rice water" stool) if my memory serves me correct.
Hope i helped you
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