AWWA JAW60139

In 2002, perchlorate was discovered in the water distribution system of Levelland, Texas. This study was undertaken to explain the source of the perchlorate, which an investigation determined had come from an aboveground steel storage tank. This was the first known in situ electrochemical production of perchlorate within a public water distribution system. The results of the study presented in this article imply that changes in the standard operating procedure for cathodic protection systems may be required, because there is the possibility that normally operated active cathodic protection systems on steel tanks could produce perchlorate, and possibly chlorate, posttreatment. The information in this article will be useful to utility managers to alert them to this potential problem.