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 Distribution System January 27, 2017 How to Study for Water Treatment License Exams – Part 2 of 10 July 9, 2018 Calculating Cubic Yards Removed – Distribution Systems November 17, 2016 Post author: Post published:January 11, 2017 Post category:Certification Exams / Distribution / Water Treatment