Water Storage Facilities

Question 1

True or false? When troubleshooting for water quality problems in storage tanks and distribution systems, chlorination is a potential solution for color problems.

Answer 1

True

Question 2

True or false? New storage facilities and existing facilities that have been repaired, cleaned, painted, or had cathodic protection installed must be disinfected.

Answer 2

True

Question 3

True or false? Chlorine gas is used with small-capacity storage tanks because of the relatively high price of chlorine.

Answer 3

False

Question 4

True or false? Elevated tanks are placed high above a service area and are used primarily to maintain adequate and uniform pressure to the area.

Answer 4

True

Question 5

True or false? To protect piping systems from hydraulic transients, surge arrestors control unusual water level changes that may result in dangerous situations.

Answer 5

False

Question 6

True or false? Predictive maintenance tries to predict when a failure might occur so corrective action can be performed before a failure occurs.

Answer 6

True

Question 7

True or false? In larger systems, water hammer can be produced from slowly repeated start and stop cycles.

Answer 7

False. It can be produced from RAPIDLY repeated start and stop cycles

Question 8

True or false? Without a surge relief system, surge pressures from sudden changes in fluid velocity can damage pipes and equipment and injure personnel.

Answer 8

True

Question 9

True or false? Cathodic protection is an electrical system used to prevent rust, corrosion, and pitting of metal surfaces in contact with water, wastewater, or soil.

Answer 9

True

Question 10

True or false? One benefit of storing water in a distribution system is that reserve water supplies are provided for agricultural and recreational purposes.

Answer 10

False

Question 11

What must you do before starting a centrifugal pump?

a. Properly prime the pump
b. Examine the discharge valve
c. Follow correct lockout/tagout procedures
d. Check to see if the water seals are function properly

Answer 11

properly prime the pump

Question 12

What are guidelines for hiring a commercial diver for interior tank inspection and cleaning?

a. use locally know divers
b. Use scuba equipped or sport trained divers
c. Use only qualified divers who have completed a commercial diver training program approved by the association of commercial diving educators
d. Use divers with at least five years of experience

Answer 12

Use only qualified divers who have completed a commercial dive training program approved by the Association of Commercial Diving Educators

Question 13

What is the main function of a distribution storage facility?

a. To quickly route water to the treatment plant
b. To take care of daily demands and peak demands
c. To handle consumer complaints
d. To handle emergency supplies

Answer 13

to take care of daily demands and peak demands

Question 14

What is corrective maintenance?

a. The repair or adjustment of equipment and facilities that is necessary when a problem already exists
b. Maintenance on a water storage facility following vandalism, localized corrosion, or splits due to extensive metal loss
c. The repair or adjustment of equipment and facilities that is done before deterioration takes place
d. Maintenance that tries to predict when a failure might occur so corrective action can be performed

Answer 14

The repair or adjustment of equipment and facilities that is necessary when a problem already exists

Question 15

Where should all storage facilities be located?

a. Away from population centers
b. Next to convenient drainage areas
c. Close to areas subject to flooding
d. Above drainage areas and locations subject to flooding

Answer 15

Above drainage areas and locations subject to flooding

Question 16

What is preventive maintenance?

a. The repair or adjustment of equipment and facilities that is done before deterioration takes place
b. Maintenance that tries to predict when a failure might occur so corrective action can be performed
c. The repair or adjustment of equipment and facilities that is necessary when a problem already exists
d. Maintenance on a water storage facility following vandalism, localized corrosion, or splits due to extensive metal loss

Answer 16

the repair or adjustment of equipment and facilities that is done before deterioration takes place

Question 17

What must you do before discharging water with a chlorine residual of 2mg/L or more?

a. Make sure the point of discharge is able to accept the water with chlorine residual at that level
b. Dilute the water with additional water or neutralize the chlorine
c. Bring the residual chlorine up to 4 mg/L or more
d. Add additional chlorine

Answer 17

dilute the water with additional water or neutralize the chlorine

Question 18

How can you determine the volume of water in a reservoir?

a. By measuring the current use statistics
b. By looking at past records
c. By studying the water turbidity levels
d. By knowing the water level

Answer 18

knowing the water level

Question 19

What is electromotive force (EMF)?

a. The electrical pressure to stop a flow current (amperage)
b. The electrical pressure available to cause a flow of current (amperage) when an electric circuit is opened
c. The electrical pressure available to cause a flow of current (amperage) when a electric circuit is closed
d. The electrical pressure lacking for a flow of current (amperage)

Answer 19

the electrical pressure available to cause a flow of current (amperage) when an electric circuit is closed

Question 20

What is there a significant danger of when all pumps are operating at full capacity?

a. Incomplete water treatment
b. Hydraulic transients
c. Backsiphonage into the water supply
d. flooding

Answer 20

backsiphonage into the water supply

Question 21

How long should a tank stand unused before filling after it is sprayed with hypochlorite solution?

a. It is immediately ready for use
b. Until after it has been rinsed with potable water
c. For at least 30 mins
d. For at least 24 hours

Answer 21

at least 30 minutes

Question 22

What is a potential solution for turbidity when troubleshooting water quality problems in storage tanks and distribution systems?

a. Install a backflow prevention device
b. Increase the chlorine dosage
c. Increase pumping levels
d. Flush mains

Answer 22

Flush the mains

Question 23

What are clear wells used for?

a. To store groundwater before treatment
b. To store unfiltered water from a treatment plant
c. To store filtered water from a treatment plant
d. To store waster water before treatment

Answer 23

3. store filtered water from a treatment plant

Question 24

What does out-of-service tank cleaning consist of?

a. Using commercial divers to clean the tank
b. Draining, washing, and disinfecting the tank before returning it to service
c. Using a vacuum-like piece of equipment to remove the soft sediment at the bottom of the tank
d. Using remotely operated equipment to clean the tank

Answer 24

draining, washing, and disinfecting the tank before returning it to service

Question 25

What is done with the remaining mixture of chlorine and water after a water storage tank has been disinfected? a. It must be properly disposed of b. It can be discharged to surface water c. It can be stored for emergency uses d. It can augment the potable water supply

Answer 25

It must be properly disposed of

Question 26

Which questions must be asked to select a suitable type or storage facility? 1. What is the maximum-day use? 2. What is the maximum-hourly use? 3. What type of pressure will the facility be required to provide and maintain throughout the system? 4. What size facility will be necessary to fulfill the requirements for emergencies such as fire flow? 5. What is the minimum- day use

Answer 26

1. What is the maximum- day use? 2. What is the maximum- hourly use? 3. What type of pressure will the facility be required to provide and maintain throughout the system? 4. What size facility will be necessary to fulfill the requirements for emergencies such as fire flow?

Question 27

What are standpipes usually constructed from? 1. Steel 2. Concrete 3. Asbestos- cement 4. PVC 5. Copper

Answer 27

1. steel | 2. concrete

Question 28

Which factors influence the selection of the type of storage facility or tank? 1. The history of the utility's storage facilities 2. The systems individual needs 3. The facility's budget 4. The type of terrain where it will be installed 5. The qualifications

Answer 28

2. the system's individual needs | 4. the type of terrain where it will be installed

Question 29

Which are abnormal operating conditions for storage tanks? 1. Excessive water demands such as fire demands 2. Broken or out-of-service pumps, mains, or tanks 3. Stale water in tanks creating tastes and odors in systems before design demand and flows develop 4. Meeting demands during peak periods 5. Sufficient available off peak electrical energy

Answer 29

1. excessive water demands such as fire demands 2. broken or out-of-service pumps, mains or tanks 3. stale water in tanks creating tastes and odors in systems before design demand flows develop

Question 30

Which are the recommended steps when starting an electric motor-driven centrifugal pump? 1. Check the lubrication, prime the pump, and make sure that the pump and suction piping are free of air 2. Reduce the electric current and water surge on startup by starting the pump with the discharge valve closed or throttled 3. Open the discharge valve slowly as soon as the pump is running 4. Inspect the packing glands to make sure that water seals are functioning properly 5. Measure the running amperage and investigate any abnormal demands or changes from the usual readings

Answer 30

1. Check the lubrication, prime the pump, make sure that the pump and suction piping are free from air 2. Reduce the electric current and water surge on startup by starting the pump with the discharge valve closed or throttled 3. Open the discharge valve slowly as soon as the pump is running 4. Inspect the packing glands to make sure that water seals are functioning properly 5. Measure the running amperage and investigate any abnormal demands or changes from the usual readings

Question 31

Which indicators may help you decide when a tank will need cleaning? 1. Turbidities over an accepted standard 2. Excessive color 3. Unusually low and high pH readings 4. Positive bacteriological samples 5. Excessive taste and odors

Answer 31

1. Turbidities over an accepted standard 2. Excessive color 4. Positive bacteriological samples 5. Excessive taste and odors

Question 32

If water quality problems develop, you must determine:

Answer 32

- where the problem is coming from | - actions to take to solve the problem

Question 33

Why are water storage facilities inspected as part of a preventative maintenance program?

Answer 33

- To determine the structural conditions of the storage reservoir - To identify any sanitary defects in the storage system - To evaluate the need for cleaning the storage facility - To determine maintenance needs and the effectiveness of the maintenance program - To identify existing or potential water quality problems

Question 34

Which factors affect the longevity of a storage facility coating?

Answer 34

- Proper surface preparation - A good durable paint - Quality workmanship - Adequate drying and aging - Proper maintenance through periodic inspection and spot, partial, or complete removal of old paint and repainting as necessary

Question 35

Which inspections should be made of the coating of a tank's interior?

Answer 35

- A visual inspection from the roof hatch with the water level lowered to about half-full or less - A detailed inspection after draining and washing the tank - A detailed inspection using divers and video cameras and then cleaning the tank w/ a device similar to a vacuum cleaner

Question 36

Which additives should you avoid in paints and coatings for water storage tanks?

Answer 36

- Lead - PCBs - Trichloroethylene - Tetrachloroethylene

Question 37

Which substances in water can influence the rate of corrosion in a tank?

Answer 37

- Dissolved oxygen - carbon dioxide - sulfate-reducing bacteria

Question 38

Which methods can help control corrosion in water storage tanks?

Answer 38

- Zinc coating on the exterior of a tank - Nonmetallic coatings such as coal tar enamels, asphaltics, cement mortar, epoxy resins, vinyl resins and paints, coal tar-epoxy enamels, silicate paints, and zinc paints - Chemicals added during the water treatment such as calcium hydroxide, sodium carbonate, zinc orthophosphate, and silicate compounds - Cathodic protection

Question 39

When disinfecting a water storage tank by filling the tank with water with an effective chlorine concentration, what is the desired chlorine residual?

Answer 39

3 mg/L

Question 40

What steps do you take to return a tank with negative bacteriological results (no coliforms) to service?

Answer 40

- Empty the tank of chlorinated water. - If acceptable, discharge the chlorinated water to a storm drainage system - Open the outlet valve from the tank to the distribution system - Make sure the inlet valve to the tank is open so that the tank will float on the system - If appropriate, remove the interim method of providing water to the distribution system

Question 41

How do you maintain concrete water storage facilities?

Answer 41

1. Screen vents and overflows to keep animals out of the facility 2. Drain, clean, and inspect concrete facilities during the second year of service and every other year thereafter 3. Use approved materials for painting, coating, or repairs 4. Disinfect facilities after inspection and repair 5. Follow safe procedures before entering and when inside a concrete storage facility

Question 42

How can you minimize ice formations?

Answer 42

1. Continuously fluctuate reservoir water surface levels 2. Adjust pumping and flow rates into and out of the reservoir 3. Temporarily suspend use of automatic controls, particularly during low-consumption hours 4. Equip storage tanks with small compressors to circulate water in the tank

Question 43

Which steps can you take to restore operation if excessive ice builds up inside an elevated water distribution system reservoir or if the tank malfunctions due to icing?

Answer 43

1. Valve off the affected tank and pressurize the distribution system using alternate means 2. Attach pressure relief valves at strategic locations if high pressure has built up 3. Waste excess water to a storm sewer 4. Operate all water pumps manually 5. Use a steam generator to thaw the ice

Question 44

What are booster pumps used for?

Answer 44

- to increase the pressure in the mains on the discharge side of the main pumps - to supply water to an elevated storage tank - to supply water to a service area at a higher elevation

Question 45

What can cause a centrifugal pump to not deliver water?

Answer 45

- Suction lift is too high. - Speed too low - Rotation is in the wrong direction