Water Quality A bacterium, virus, or other microorganism that can cause disease. Tags: Certification Exam Prep, Distribution System, Pathogen, Water Quality, Water Treatment Read more articles Previous PostLime Softening Next PostWater Main Installation You Might Also Like Leadership and Communication November 6, 2015 Advanced Treatement January 20, 2017 Fire Hydrants & Valves January 19, 2017 Post author: Post published:January 28, 2017 Post category:Certification Exams / Distribution / Wastewater Treatment