of water contamination
in which the number of the colonies of coliform-bacteria Escherichia coli (E. coli) per 100 milliliter
of water is counted. The result
is expressed as 'Coliform Microbial Density' and indicates the extent of fecal matter present in it. According to common
standards drinking water must be completely free
from any colony, bathing and swimming pool
water can have about 200 colonies, and recreational (fishing and boating) water about 1000 colonies.