The occurrence of microorganisms in water main encrustations

Colonization of microorganisms and resultant high bacterial populations often occur on or within protective encrustations or tubercules inside a distribution system. Formation of these encrustations is affected by a variety of physical, chemical, and biological activities within the pipes, which can be examined in situ by scanning electron microscopy (SEM). SEM photographs demonstrate graphically the survival of microorganisms in the distribution system and their possible role in tubercle formation.