Comparison of bacterial regrowth in distribution systems using free chlorine and chloramine: a statistical study of causative factors

摘要

Bacterial regrowth was investigated over a 15-month period in distribution systems (DSs) of Durham and Raleigh in North Carolina. These two water utilities were chosen because they are adjacent to one another, have similar service Area characteristics, and treat surface waters of similar characteristics with conventional processes (coagulation- Sedimentation and dual-media filtration). The finished waters have similar chemical quality and regrowth potential as Measured by assimilable organic carbon (AOC). The major difference in treatment is the choice of final disinfectants (chlorine in Durham and chloramine in Raleigh).