What does MWRA do about bacteria in drinking water?
Bacteria are everywhere we go in the world, but there are certain types of bacteria we don’t want to see in our water supply, because of public health concerns. Communities regularly take water samples, which are then analyzed in laboratories for bacteria counts. A particular type of bacteria that they test for — coliform — serves to indicate that harmful germs may also be present. If coliform are found in 5% or more of the samples collected in a month, the community is required by law to notify residents in their locale. In addition, when coliform are found in samples, the lab conducts additional testing to determine if a specific type, E. coli, is present. If E.coli is present, this is considered evidence of a critical public health concern. Usually the solution in this case is to boil the water until the problem is solved.
