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 Texas Drinking Water Quality May 24, 2017 Sample Preservation January 18, 2017 BOD Removal Efficiency Problem – Wastewater Math June 12, 2017 Post author: Post published:January 11, 2017 Post category:Certification Exams / Distribution / Water Treatment