Water Storage Facilities Flashcards
True or false? When troubleshooting for water quality problems in storage tanks and distribution systems, chlorination is a potential solution for color problems.
True
True or false? New storage facilities and existing facilities that have been repaired, cleaned, painted, or had cathodic protection installed must be disinfected.
True
True or false? Chlorine gas is used with small-capacity storage tanks because of the relatively high price of chlorine.
False
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.
True
True or false? To protect piping systems from hydraulic transients, surge arrestors control unusual water level changes that may result in dangerous situations.
False
True or false? Predictive maintenance tries to predict when a failure might occur so corrective action can be performed before a failure occurs.
True
True or false? In larger systems, water hammer can be produced from slowly repeated start and stop cycles.
False. It can be produced from RAPIDLY repeated start and stop cycles
True or false? Without a surge relief system, surge pressures from sudden changes in fluid velocity can damage pipes and equipment and injure personnel.
True
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.
True
True or false? One benefit of storing water in a distribution system is that reserve water supplies are provided for agricultural and recreational purposes.
False
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
properly prime the pump
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
Use only qualified divers who have completed a commercial dive training program approved by the Association of Commercial Diving Educators
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
to take care of daily demands and peak demands
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
The repair or adjustment of equipment and facilities that is necessary when a problem already exists
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
Above drainage areas and locations subject to flooding
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
the repair or adjustment of equipment and facilities that is done before deterioration takes place
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
dilute the water with additional water or neutralize the chlorine
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
knowing the water level
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)
the electrical pressure available to cause a flow of current (amperage) when an electric circuit is closed
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
backsiphonage into the water supply
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
at least 30 minutes
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
Flush the mains
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
- store filtered water from a treatment plant
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
draining, washing, and disinfecting the tank before returning it to service
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
It must be properly disposed of
Which questions must be asked to select a suitable type or storage facility?
- What is the maximum-day use?
- What is the maximum-hourly use?
- What type of pressure will the facility be required to provide and maintain throughout the system?
- What size facility will be necessary to fulfill the requirements for emergencies such as fire flow?
- What is the minimum- day use
- What is the maximum- day use?
- What is the maximum- hourly use?
- What type of pressure will the facility be required to provide and maintain throughout the system?
- What size facility will be necessary to fulfill the requirements for emergencies such as fire flow?
What are standpipes usually constructed from?
- Steel
- Concrete
- Asbestos- cement
- PVC
- Copper
- steel
2. concrete
Which factors influence the selection of the type of storage facility or tank?
- The history of the utility’s storage facilities
- The systems individual needs
- The facility’s budget
- The type of terrain where it will be installed
- The qualifications
- the system’s individual needs
4. the type of terrain where it will be installed
Which are abnormal operating conditions for storage tanks?
- Excessive water demands such as fire demands
- Broken or out-of-service pumps, mains, or tanks
- Stale water in tanks creating tastes and odors in systems before design demand and flows develop
- Meeting demands during peak periods
- Sufficient available off peak electrical energy
- excessive water demands such as fire demands
- broken or out-of-service pumps, mains or tanks
- stale water in tanks creating tastes and odors in systems before design demand flows develop
Which are the recommended steps when starting an electric motor-driven centrifugal pump?
- Check the lubrication, prime the pump, and make sure that the pump and suction piping are free of air
- Reduce the electric current and water surge on startup by starting the pump with the discharge valve closed or throttled
- Open the discharge valve slowly as soon as the pump is running
- Inspect the packing glands to make sure that water seals are functioning properly
- Measure the running amperage and investigate any abnormal demands or changes from the usual readings
- Check the lubrication, prime the pump, make sure that the pump and suction piping are free from air
- Reduce the electric current and water surge on startup by starting the pump with the discharge valve closed or throttled
- Open the discharge valve slowly as soon as the pump is running
- Inspect the packing glands to make sure that water seals are functioning properly
- Measure the running amperage and investigate any abnormal demands or changes from the usual readings
Which indicators may help you decide when a tank will need cleaning?
- Turbidities over an accepted standard
- Excessive color
- Unusually low and high pH readings
- Positive bacteriological samples
- Excessive taste and odors
- Turbidities over an accepted standard
- Excessive color
- Positive bacteriological samples
- Excessive taste and odors
If water quality problems develop, you must determine:
- where the problem is coming from
- actions to take to solve the problem
Why are water storage facilities inspected as part of a preventative maintenance program?
- 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
Which factors affect the longevity of a storage facility coating?
- 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
Which inspections should be made of the coating of a tank’s interior?
- 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
Which additives should you avoid in paints and coatings for water storage tanks?
- Lead
- PCBs
- Trichloroethylene
- Tetrachloroethylene
Which substances in water can influence the rate of corrosion in a tank?
- Dissolved oxygen
- carbon dioxide
- sulfate-reducing bacteria
Which methods can help control corrosion in water storage tanks?
- 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
When disinfecting a water storage tank by filling the tank with water with an effective chlorine concentration, what is the desired chlorine residual?
3 mg/L
What steps do you take to return a tank with negative bacteriological results (no coliforms) to service?
- 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
How do you maintain concrete water storage facilities?
- Screen vents and overflows to keep animals out of the facility
- Drain, clean, and inspect concrete facilities during the second year of service and every other year thereafter
- Use approved materials for painting, coating, or repairs
- Disinfect facilities after inspection and repair
- Follow safe procedures before entering and when inside a concrete storage facility
How can you minimize ice formations?
- Continuously fluctuate reservoir water surface levels
- Adjust pumping and flow rates into and out of the reservoir
- Temporarily suspend use of automatic controls, particularly during low-consumption hours
- Equip storage tanks with small compressors to circulate water in the tank
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?
- Valve off the affected tank and pressurize the distribution system using alternate means
- Attach pressure relief valves at strategic locations if high pressure has built up
- Waste excess water to a storm sewer
- Operate all water pumps manually
- Use a steam generator to thaw the ice
What are booster pumps used for?
- 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
What can cause a centrifugal pump to not deliver water?
- Suction lift is too high.
- Speed too low
- Rotation is in the wrong direction
