Bacteria which are found in wells can be divided into two broad classes: disease causing bacteria, of which E. Coli is the most famous example, and nuisance bacteria, which are responsible primarily for aesthetic problems.
Nuisance bacteria are most commonly revealed through measurements of heterotrophic plate count or background. At high concentrations these bacteria form thick slimy layers called biofilms on well surfaces. This process is called biofouling. As these bacteria carry out their life processes they release various materials into the well water. They can therefore be responsible for iron, sulphur, and other problems.
At low concentrations, shocking the well with Wellrific is an effective means to control nuisance bacteria. At higher concentrations the installation of an automated down well injection system may be advisable. An ultra violet disinfection system may also be called for in cases of high levels of contamination.