Corrosion Control If sequestration of iron and manganese is practiced, the chlorine residual in the water system should always be maintained at or above: Tags: Certification Exam Prep, Chlorine Residual, Distribution System, Iron, Manganese, Sequestration, Water Treatment Read more articles Previous PostWater Treatment and Distribution System Next PostWater Treatment and Distribution System You Might Also Like Effect of pH on Disinfection September 12, 2017 Texas Class C Water System Operator Requirements (part 2) June 15, 2017 Work and Holidays December 7, 2015 Post author: Post published:January 11, 2017 Post category:Certification Exams / Distribution / Water Treatment