Question 1010 of 229 · California Water Distribution Operator Exam
Which substances commonly create chlorine demand in a distribution system?
Exactly one answer is correct.
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Correct answer to question 1010
- C: Organic matter, iron, manganese, hydrogen sulfide and ammonia
Explanation
Reduced compounds and organics react with chlorine and use it up before a residual can form. Hardness ions and dissolved gases such as oxygen do not consume chlorine in this way.
More questions: Disinfection
- 1011The total chlorine residual equals which combination?
- 1012Which test is most often used by operators in the field to measure chlorine residual?
- 1013A sudden drop of chlorine residual at a dead-end hydrant most likely points to what?
- 1014Before a newly disinfected main is placed in service, what must the bacteriological samples show?
- 1015Which standard covers the disinfection of new and repaired water mains?
- 1016A well is most likely to need disinfection in which situation?