Introduction To Water Distribution System Flashcards
What is stratification in lakes and reservoirs?
a. Breezes starting the circulation of surface water
b. Formation of separate layers of temperature, plant life, or animal life
c. Lake turnover due to temperature changes
d. Uniform water temperature profile from surface to bottom
Formation of separate layers of temperature, plant life, or animal life
What causes the elevation and slope of water tables and artesian pressure levels to change?
a. Collection of water into a reservoir
b. Pollution from agricultural activities
c. Seasonal variations in the supply of water
d. Selection of intake structures
Seasonal variations in the supply of water
How extensive should the treatment be for reclaimed water?
a. Depends on climate conditions at point of use
b. Depends on potential exposure to the public
c. Depends on the funds available for treatment
d. Depends on the NPDES permit
Depends on potential exposure to the public
The water distribution system must have sufficient capacity to meet:
- Maximun water demands
- Firefighters requirements
- Maintain adequate water pressure
What is one difference between primary and secondary drinking water regulations?
a. Primary regulations are mandatory limits while secondary regulations are guidelines
b. Primary regulations limit chemical contaminants while secondary regulations limit biological contaminants
c. Primary regulations cannot be changed while Pronadary regulations are constantly changing
d. Primary regulations apply to treatment plants while secondary regulations apply to distribution systems
Primary regulations are mandatory limits while secondary regulations are guidelines
What is palatable water?
a. Water at a desirable temperature that is free from objectionable tastes, odors, colors, and turbidity
b. Water that does not contain objectionable pollution, contamination, minerals, or infective agents and is considered satisfactory for drinking
c. Water in its natural state, before any treatment
d. Water having a low concentration of calcium and magnesium ions
Water at a desirable temperature that is free from objectionable tastes, odors, colors, and turbidity
- Once groundwaters are contaminated, it normally takes a considerable time before they recover because of
The slow movement of the water in the ground
- What are the two causes of backflow through, cross-connection?
a. Low circulation and stagnant water
b. Chemical and electrochemical reactions
c. Back pressure and backsiphonage
d. Pockets of sediments and slimes
Back pressure and backsiphonage
Which form of chlorine is most effective against biofilms?
a. Free chlorine
b. Chlorine dioxide
c. Chlorine residual
d. Chloramines
Chloramines
What influences the potential for corrosion in metal or asbestos pipe that is lined with asphalt or coal tar?
a. Increased chlorine demand
b. Amount of interface in the pipe
c. Proximity to hazardous facilities
d. Integrity of the coating
Integrity of the coating
How often should reservoirs be inspected?
a. At least once a month
b. At least twice a month
c. At least daily
d. At least twice a week
At least twice a month
Why are uncovered reservoirs often prohibited?
a. Subject to contamination from many sources
b. Must be located far from other system facilities
c. Rarely produce sufficient system pressures
d. Difficult to construct and repair
Subject to contamination from many sources
What is an important aspect of a tank inspection and maintenance program?
a. Ensuring adequate turnover of water in the tank
b. Main replacement and repair procedures
c. Unidirectional flushing
d. Investigating and responding to complaints
Ensuring adequate turnover of water in the tank
Why should an O&M program include exercising the valves?
a. To control biofilm
b. To prevent backflow
c. To ensure proper setting and operation
d. To eliminate dead ends
To ensure proper setting and operation
What is the responsibility of water treatment plant operators?
a. Avoid boil-water orders
b. Minimize costs of producing drinking water
c. Produce safe and pleasant drinking water
d. Successfully pass operator certification examinations
Produce safe and pleasant drinking water
