Intro to Water Distribution

Question 1

True or False? Chlorination is the most common means of disinfection used today to protect the public’s health.

Answer 1

True

Question 2

True or False? As water mains and reservoirs become older, they require less and less maintenance.

Answer 2

False. They require more

Question 3

True or False? Routine water quality monitoring consists of collecting samples at remote locations in the system and testing for chlorine residual and coliforms

Answer 3

True

Question 4

True or False? Existing contaminant limits may be modified if EPA’s ongoing research reveals new information about the effects of a particular substance.

Answer 4

True

Question 5

True or False? Reservoirs that are not heavily used can be a source of taste, odor, and contamination problems.

Answer 5

True

Question 6

True or False? When someone contacts you complaining that their drinking water looks muddy, tastes bad, or smells bad, you need not be concerned.

Answer 6

False. You may have a serious problem

Question 7

True or False? Lack of circulation in a dead end creates nearly ideal conditions for degrading water quality.

Answer 7

True

Question 8

Are groundwaters less or more susceptible to contamination than surface water?

Answer 8

Less

Question 9

True or False? A water supply that is satisfactory in quality for one purpose might be entirely unsatisfactory for another.

Answer 9

True

Question 10

Which is considered a more powerful disinfectant? Chloramines or chlorine?

Answer 10

Chlorine

Question 11

Under what conditions may water mains be located adjacent to sewer lines?

Answer 11

When physical conditions or soil conditions prevent minimum separation distances from being met

Question 12

How can corrosion be prevented on the insides of cement or metal pipes?

Answer 12

Line with asphalt or coal tar coatings

Question 13

The knowledge and skills required to work as a water distribution system operator in a given system depend on:

Answer 13

the size and type of water distribution system

Question 14

What are organics?

Answer 14

chemical substances that are based on the element carbon

Question 15

Why are cloramines more effective against biofilms than chlorine?

Answer 15

They are more persistent

Question 16

Why have drinking water quality standards been prepared and used?

Answer 16

To provide the needed quality control and ensure the acceptability of the product

Question 17

Why is water quality monitoring of distribution systems important?

Answer 17

To identify when and where water quality changes occur in the system

Question 18

When water lines are being repaired, how can possible contamination of the water be prevented?

Answer 18

Keep the hole dewatered

Question 19

What are pathogens?

Answer 19

disease causing organisms

Question 20

What is the primary responsibility of a water treatment plant?

Answer 20

To produce a safe and palatable water

Question 21

Perhaps the greatest water quality nuisance is:

Answer 21

Corrosion and precipitation of iron

Question 22

What types of consumer complaints can result from hydrant testing and flushing programs?

Answer 22

Dirty water complaints

Question 23

What is the purpose of adequate and reliable records?

Answer 23

To document the effectiveness of the operation

Question 24

Every operator’s responsibility with regard to safety is:

Answer 24

Be sure that the facilities are a safe place to work and that everyone follows safe procedures

Question 25

What should you do after investigating a drinking water complaint?

Answer 25

Notify the person who complained of the results and what corrective action was or will be taken

Question 26

Treated water storage facilities at water treatment plants are called:

Answer 26

Clear wells

Question 27

What does the term water quality describe?

Answer 27

The composite chemical, physical, and biological characteristics of a water supply.

Question 28

One of the best results from a well-guided tour of water system facilities is:

Answer 28

gaining support to obtain the funds necessary to run a good operation

Question 29

What conditions in water main dead ends can produce carbon dioxide, methane, and sulfide odors?

Answer 29

Anaerobic

Question 30

What is backsiphonage?

Answer 30

form of backflow caused by a negative or below atmospheric pressure within the water supply piping

Question 31

What could be the cause of milky water?

Answer 31

Air

Question 32

The water supply system's ultimate consumers:

Answer 32

- Homes - Industrial water users - Businesses

Question 33

Groundwater may require treatment to remove:

Answer 33

- excessive hardness - iron and manganese - dissolved gases - taste- and odor-causing substances

Question 34

What are the possible causes of water quality degradation in water storage facilities?

Answer 34

- Contamination entering through improperly maintained covers - Small animals that gain access through improperly screened overflows - Inadequate disinfection of reservoirs after construction or repairs - Failure of side walls of below-ground reservoirs - Materials introduced to uncovered reservoirs

Question 35

How may large variations in flow through a distribution system adversely affect water quality?

Answer 35

- Low circulation and stagnant water can result in the growth of organisms, formations of sediments and corrosion products, depletion of oxygen, and increased tastes and odors - Turbulence can entrain air into the supply causing milky water, which is objectionable to consumers - Changes in water velocity and flow reversals can result in sediments being stirred up and carried along until they reach the consumer

Question 36

Typical duties of a water distribution system operator:

Answer 36

- Place barricades, signs, and traffic cones around work sites to protect operators and the public - Excavate trenches and install shoring - Lay, connect, test, and disinfect water mains - Tap into water mains - Flush and clean water mains

Question 37

Which diseases are transmitted by internal parasites in water?

Answer 37

- Cryptosporidiosis | - Giardiasis

Question 38

Which types of constituents have limits under primary drinking water standards?

Answer 38

- Organic chemicals - Inorganic chemicals - Microorganisms - Disinfection byproducts

Question 39

Factors that may cause water quality degradation include:

Answer 39

- Cross-connections - Corrosion - Biological growth and activity - Time in the system - Dead ends

Question 40

Which supervision and administration tasks might be included in a water distribution system operator's duties?

Answer 40

- Giving advice on future planning - keeping adequate reliable records - giving advice on budget requirements - training new operators - encouraging operators to strive for higher levels of certification

Question 41

Potential safety hazards for water distribution system operators:

Answer 41

Working in traffic Excavating for the installation or repair of pipes Painting facilities without adequate ventilation

Question 42

Some components of the water distribution system:

Answer 42

- Network of pipes - Valves - Fire hydrants - Service lines - Meters,

Question 43

Which items are possible contamination sources for open reservoirs?

Answer 43

- Atmospheric contaminants - Animals, including birds and rodents - Vandalism - Illegal bathing and fishing - Windblown contaminants

Question 44

Which operating procedures can result in water quality degradation in a distribution system?

Answer 44

- Poorly performed water quality monitoring and flushing programs - Inadequate cross-connection control - Insufficient surveillance to determine whether the protective features for storage facilities and mains are still adequate - Tolerance of low or negative pressures in the distribution system - Inadequate disinfection after repair or installation of new facilities

Question 45

Why is the iron precipitated by the iron bacteria, Crenothrix, of special concern in water distribution systems?

Answer 45

- reduces pipe carrying capacity - produces color in water - forms deposits in pipes

Question 46

How can chemicals used at water treatment facilities cause water quality problems?

Answer 46

- Excessive use of manganese compounds for taste and odor control results in a colored water - Overdosing alum during coagulation treatment results in turbidity and deposits - Chlorinating water containing organic materials results in the formation of THMs - Improper chlorination causes objectionable tastes and odors

Question 47

Which criteria must a domestic water supply meet to be considered of good quality?

Answer 47

- Free of toxic chemicals - free of disease-causing organisms - will satisfy to a maximum degree the requirements of domestic and industrial consumers - of such a chemical composition that it may be distributed without undue corrosive or scale-forming effects on the water distribution system - attractive in taste and appearance

Question 48

Under what conditions would water quality not change in the distribution system?

Answer 48

- If the water were completely stable - if the system were completely sealed off from any intrusion - if the water were biologically sterile - if the system were inert to water

Question 49

How can water in below-ground reservoirs be subject to contamination?

Answer 49

- From flooding by surface stormwaters - from windblown contamination - from materials that enter through failures in the side walls - from vandalism