Mass Drinking Water Distribution Grade 1 Study Guide
Complete Solutions With Latest Updates
After a new water mains is installed and pressure tested it
... [Show More] should be Correct Answer: Filled with a
solution of 25ppm to 50ppm free chlorine for at least 24 hours prior to flushing
As the temperature of water increases the disinfection process Correct Answer: more effective
Water with a ph of 8.0 is considered Correct Answer: basic
What is a low voltage electrical system that is used to prevent rust corrosion and pitting of metal
surfaces in contact with water Correct Answer: cathodic protection
Which conventional treatment step is eliminated by direct filtration Correct Answer: Sedimentation
A granular white powder used for disinfection Correct Answer: Calcium hypochlorite
What is the chlorine dose Correct Answer: Chlorine demand plus chlorine residual
What is a cross connection Correct Answer: an unprotected connection between a drinking water
supply and a system not approved as safe
What is an air gap separation device Correct Answer: a vertical empty space that seperates a
drinking water suppy from an unapproved water system
Breakpoint chlorination is the addition of chlorine into the water until what occurs Correct Answer: the
chlorine demand has been satisfied
What is the main difference between using hypochlorite compounds and chlorine gas Correct
Answer: the % of available chlorine
What is disenfection Correct Answer: process that kills or inactivates most microorganism and
pathogens
Why is backflow a concern for water distribution systems Correct Answer: flow from a non potable
water source could contaminate the water system
Which of the following has caused more waterborne disease outbreaks than any other reported factor
Correct Answer: cross connection contamination
What contaminant causes methemoglobinemia Correct Answer: nitrate
What is the physical connection direct or indirect which provides the opportunity for nonpotable water
to enter a conduit pipe or receptacle containing potable water Correct Answer: cross connection
What are two most important safety concerns when entering an confined space Correct Answer:
oxygen deficiency and hazardous gasses
What contaminant causes methemoglobinemia Correct Answer: nitrate
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