MICROBIOLOGICAL TUBERCULATION

(Water Quality) A condition in older water distribution pipes characterized by reddish brown mounds of various heights attached to the interior of the pipe wall. These mounds are the result of many years of iron and manganese bacterial growth that deposit iron and/or manganese oxides along with particulate matter from the water trapped in the biomass from generations of bacteria. An aging distribution system experiencing this problem is typically characterized by red water, taste and odor problems, turbidity, reduced pressure and flow rates, and a low chlorine residual. Iron bacteria are very common in all water sources with over twenty different iron bacteria that can cause tuberculation. They are generally considered to be non-pathogenic. Tuberculation usually begins with a slime that may show signs of iron oxide precipitation. The iron bacteria, which attach themselves to the interior surface of the pipe, metabolize ferrous ions from the water as an energy source, precipitating ferrous oxide which becomes trapped in the biomass of the tuberculation. In the past, tuberculation usually resulted in replacement of the water distribution pipe; however, more recently, chemical treatments of isolated sections of pipeline have proven both highly effective and less costly. Also referred to as Tuberculation.