Water Distribution Grades 1 & 2 Flashcards
Which agency legal limits on the concentration levels of harmful contaminants in potable water distributed to customers?
a. National Primary Drinking Water Regulations Agency
b. US Environmental Protection Agency
c. US Public Health Service
d. Occupational Health and Safety Administration
b. US Environmental Protection agency
The number of monthly distribution system bacteriological samples required is
a. based on the water withdrawal permit limit.
b. based on the system size.
c. based on the population served.
d. different for each state.
c. based on the population served.
What is the maximum contaminant level for total trihalomethanes (TTHMs) in the United States?
a. 0.040 mg/L
b. 0.060 mg/L
c. 0.080 mg/L
d. 0.100 mg/L
c. 0.080 mg/L
Under the Surface Water Treatment Rule, disinfection residuals must be collected at the same location in the distribution system as
a. coliform samples.
b. total trihalomethanes.
c. disinfection by-products.
d. alkalinity, conductivity, and pH for corrosion studies.
a. coliform residuals.
Iron can cause “red water” and thus customer complaints when its concentration is above its secondary maximum contaminant level of
a. 0.01 mg/L
b. 0.05 mg/L
c. 0.10 mg/L
d. 0.30 mg/L
d. 0.30 mg/L
The goal of the Surface Drinking Water Act is for each _____ to accept primary enforcement responsibility (primacy) for the operation of the state’s drinking water program.
a. state
b. water treatment plant
c. operator
d. municipality
a. state
What is the objective of the Total Coliform Rule?
a. To provide Cryptosporidium protection in new facilities
b. To ensure safe levels of lead and copper in drinking water
c. To protect the public from exposure to Giardia and Cryptosporidium
d. To promote routine surveillance of distribution system water quality to search for fecal matter and/or disease-causing bacteria
d. To promote routine surveillance of distribution system water quality to search for fecal matter and/or disease-causing bacteria
Which agency sets standards on the concentration levels of harmful contamination in drinking water?
US Environmental Protection Agency
What is the difference between the different Tiers of violations and which on is the most serious?
- Tier 1 is an acute MCL violation: requiring public notification within 24 hours - and is the Most Serious
- Tier 2 violations: require public notification within 30 days
- Tier 3 violations: require public notification within 1 year
A positive E. coli test must be reported to the primacy health agency within what time period?
24 hours
How is the required number of monthly bacteriological samples determined?
By the population served
What is the action level for lead in first-draw samples taken from customer taps?
0.015 mg/L or 15 ppb
What authority provides specific sampling instructions?
The state primacy agency (Department of Health)
According to the Lead and Copper Rule, what is the action level for lead?
0.015 mg/L (15 ppb)
A water system is designated a “community public water supply” if it serves how many homes?
15 or more homes
What is the formula for calculating Detention time in Hours?
Detention Time (hrs) = Total Volume (gal) x 24 hrs/day then divide by Daily Flow (gals/day)
What resource allows you to convert to units, such as feet to inches, simply by following the instructions in the table heading?
A conversion table
How many gallons are in a cubic foot?
7.48 gallons in a cubic foot
If the water level rises by 15 feet, how many yards has it risen?
5 yards
What is the formula for Average Daily Flow?
Sum of All daily flows divided by Total number of daily flows used
How do you convert deciliters to milliliters?
Multiply by 100 or Move the decimal TWO places to the RIGHT
Head pressure is measured in
a. absolute pressure.
b. gauge pressure.
c. feet.
d. foot-pounds
c. feet
A plat is
a. a map.
b. a corrosion point on a map.
c. an organelle found in some protozoans.
d. a highly corrosive soil type.
a. a map.
At which time of the day of water stored in the distribution system the oldest?
a. Early morning
b. Late morning
c. Early afternoon
d. Late evening
a. Early morning
Water mains should primarily be sized based on
a. earthquake size potential.
b. peak domestic and commercial demands.
c. peak commercial and industrial demands.
d. adequate fire flow at an appropriate pressure.
d. adequate fire flow at an adequate pressure.
The most desirable residential pressure ranges from
a. 20 to 35 psi
b. 35 to 50 psi
c. 50 to 75 psi
d. 75 to 90 psi
c. 50 to 75 psi
Domestic water use includes water that is supplied to residential areas, _____, and institutional facilities.
a. public parks
b. commercial districts
c. industrial facilities
d. municipal buildings
b. commercial districts
The Riparian Doctrine is sometimes called the “Rule of
a. first come, first serve.”
b. reasonable sharing.”
c. equal use.”
d. eminent domain.”
b. reasonable sharing.”
During which season is water use typically the highest?
Summer
Of the common types of distribution systems, which is considered the LEAST desirable?
Tree system
What type of valves should be provided so that areas within the system can be isolated for repair or maintenance?
Shutoff Valves
Head is measured in
a. absolute pressure.
b. gauge pressure.
c. feet.
d. foot-pounds.
c. feet.
If the pressure head on a fire hydrant is 134 ft, what is the pressure in psi?
a. 50 psi
b. 52 psi
c. 54 psi
d. 58 psi
d. 58 psi
- 134 ft divided by 2.31 ft/psi = 58 psi
The velocity of water is calculated as the quantity of water that flows through the pipe
a. divided by the cross-sectional area of the pipe.
b. divided by the time the water takes to reach its destination.
c. divided by the water’s weight in cubic feet.
d. multiplied by resistance to flow.
a. divided by the cross-sectional area of the pipe.
What is the term for water pressure in a main or in a container that is measured by a gauge?
Gauge Pressure
In hydraulics, how is head expressed?
Foot Pounds per Pound (ft-lb/lb)
What is the term for pressure measured in terms of height of water (in meters or feet)?
Head
What are the THREE types of head pressure?
- Elevation head
- Velocity head
- Pressure head
The highest degree of protection for the exterior of a coated steel pipe is
a. cathodic protection.
b. bituminous materials.
c. plastic coatings.
d. polyethylene tapes.
a. cathodic protection.
The C value is a measure of a pipe wall’s
a. smoothness.
b. smoothness, which allows for even flow.
c. smoothness, which retards turbulent flow.
d. roughness, which retards flow due to friction.
d. roughness, which retards flow due to friction.
Which of the following is a type of joint for ductile iron pipe?
a. Expansion joint
b. Push-on joint
c. Bell and spigot with rubber O-ring
d. Rubber gasket joint
b. Push-on joint
What is the term for a sudden repeated increase and decrease in pressure that continues until dissipated by friction losses?
a. Pipe knocking
b. Water hammer
c. Pipe shear
d. Beam breakage
b. Water hammer
Which of the following is NOT a type of joint that generally used today for connecting DIP (ductile iron pipe) and fittings?
a. Push-on joint
b. Flanged joint
c. Riveted joint
c. Riveted joint
What term refers to the process by which organic compounds pass through plastic pipe?
Permeation
What measurement of a pipe’s strength refers to its ability to withstand the pressure exerted on it after it has been buried in a trench?
External load
What type of cylinder pipe is manufactured by casting mild steel reinforcing cages and a steel cylinder with welded joint rings within a thick concrete core?
Reinforced concrete cylinder pipe
When PVC pipe is stacked loose, it should not be stacked more than how high?
a. 2.0 feet
b. 3.0 feet
c. 5.0 feet
d. 7.5 feet
b. 3.0 feet
What is the most common cause for pipe joint failure (leaking) in newly laid pipe?
a. The use of a cracked gasket
b. Not pushing the spigot end the full distance into the bell
c. Not having the joint completely clean
d. An incorrect trench bedding angle
c. Not having the joint completely clean
The backfill material for a pipe installation should contain enough _____ to allow for thorough compaction.
a. moisture
b. sand
c. gravel
d. mixed sizes
a. moisture
What is the appropriate angle of repose for average soils when using the sloping method for the prevention of cave-ins? (Note: horizontal to vertical distance, respectively)
a. 0.5 : 1.0
b. 1.0 : 1.0
c. 1.5 : 1.0
d. 2.0 : 1.0
b. 1.0 : 1.0
Which of the following statements is true regarding unloading gaskets?
a. Always have gaskets as near the trench as possible for easy installation
b. Always store gaskets in a clean, secure location until they are needed
c. Store gaskets near electric motors or other operating electrical equipment
d. Don’t worry about getting gaskets dirty while unloading, as long as they are cleaned before installation
b. Always store gaskets in a clean, secure location until they are needed
Wherever a water main crosses a sewer line, the water main should be at least _____ above or below the sewer line.
a. 12-inches
b. 18-inches
c. 24-inches
d. 30-inches
b. 18-inches
What form of pipe shipment is preferrable from the user’s standpoint because the pipe can usually be unloaded directly at the jobsite?
Truck Delivery
What is the greatest expense relating to pipe installation?
Excavation
What is the term for the process of installing tightly spaced upright planks against each other to form a solid barrier against faces of the excavation?
Sheeting
If an excavation on a road requires that one of the lanes be closed and the speed limit is 25 mph (40 kph), how many cones are required to divert the traffic?
a. 6
b. 9
c. 13
d. 15
a. 6
Which of the following is NOT generally a process used for compacting the pipe embedment and backfill placed in a trench?
a. Tamping
b. Vibrating
c. Saturating with water
d. Sifting
d. Sifting
Leakage is defined as the volume of water that must be added to the full pipeline to maintain a specific test pressure within a _____ range.
a. 10 psi
b. 5 psi
c. 3 psi
4. 12 psi
b. 5 psi
Which of the following is NOT one of the commonly used methods of applying a disinfectant to piping?
a. Stream method
b. Slug method
c. Tablet method
d. Continuous feed method
a. Stream method
Under any soil conditions, cave-in prevention is required for trenches or excavations _____ deep or more.
a. 15 feet (4.6 m)
b. 10 feet (3.0 m)
c. 5 feet (1.5 m)
d. 2 ft (0.6 m)
c. 5 feet (1.5 m)
When disinfecting a new pipeline with calcium hypochlorite tablets or granules, what should the chlorine target be?
25 mg/L
How deep should the compacted covering layer be for pipe less than 8-inches in diameter and for pipe larger than 8-inches in diameter?
- 8-inches or less = 6 - 12 inches
- 8-inches or more = 12 - 24 inches
How much leakage is allowed for a new pipeline test?
The amount is given in the AWWA Standards and manuals.
How must a pipeline be prepared before a sample is taken for bacteriological testing?
The pipeline must be flushed of chlorinated water and refilled with water from the system.
What term refers to the process of repeatedly pushing in pressurized water pipe vertically near the bottom of the loose fill at intervals along the excavation?
Jetting
A corporation stop is used for a
a. Service line.
b. Pump discharge line.
c. Tank inlet.
d. Tank outlet.
a. Service line.
Compression fittings used with copper or plastic tubing seal by means of
a. a beveled sleeve.
b. a compression ring.
c. a compressed beveled gasket.
d. compressed O-rings located at either end of the fitting’s beveled neck.
c. a compressed beveled gasket.
Water meter pits are usually used in
a. areas where flooding will most likely occur.
b. areas where flooding is very rare.
c. cold climates.
d. hot climates.
c. cold climates.
Which of the following is NOT an advantage of installing meters outside in boxes?
a. In areas where ground frost is nominal, a meter box can be relatively small, inexpensive, and easy to install
b. If the boxes can always be readily located, meter boxes can make meter reading easier because meter readers do not have to enter the building
c. In areas where there is deep frost, meter pits are much more expensive to construct
d. Placing meters outside eliminates the need to enter buildings to replace the meters, which is difficult in some inside locations
c. In areas with deep frost, meter pits are much more expensive to construct
Other utilities will allow installation of a meter in a crawl space or utility closet as long as (1) the meter can be easily accessed by a meter reader or (2)
a. the meter is equipped with a remote reading device.
b. the homeowner can easily access and report the meter readings.
c. the meter can self-report to the utility.
d. water fees in the area are fixed and readings are unnecessary.
a. the meter is equipped with a remote reading device.
What may cause galvanized iron pipe to corrode excessively?
Direct connection to brass and other dissimilar metal fittings
What is a curb stop used for?
Turning off a customer’s service for repair or as the result of nonpayment
What is the typical service line size for a single-family residence?
3/4 inch
What is the term for the valve used to connect a small-diameter service line to a water main?
Corportation Stop
What is generally considered to be the best location for a tap on a main?
At an angle of about 45 degrees down from the top of the pipe
Which type of valve should be installed at a dead-end water main?
a. Vacuum valve
b. Air valve
c. Blowoff valve
d. Pressure-relief valve
c. Blowoff valve
Which type of valve operates similar to a diaphragm valve?
a. Vacuum relief valve
b. Globe valve
c. Pressure-relief valve
d. Butterfly valve
b. Globe valve
Which type of valve can go from fully open to fully closed with a quarter turn?
a. Plug valve
b. Needle valve
c. Globe valve
d. Pinch valve
a. Plug valve
Foot valves are a special type of
a. relief valve.
b. control valve.
c. check valve.
d. plug valve.
c. check valve.
Which type of valve would be best to use to precisely throttle flow?
a. Globe valve
b. Butterfly valve
c. Rotary valve.
d. Needle valve.
d. Needle valve.
Which type of valve is used to isolate a pump on the suction side?
a. Butterfly valve
b. Globe valve
c. Gate valve
d. Ball valve
c. Gate valve
When fully opened, which type of valve will have the highest head loss?
a. Gate valve
b. Plug valve
c. Globe valve
d. Ball valve
c. Globe valve
Which type of valve will prevent the collapse of a pipe?
a. Pressure-relief valve
b. Needle valve
c. Pinch valve
d. Air-and-vacuum relief valve
d. Air-and-vacuum relief valve
List some valves used in water systems:
- Gate valve
- Globe valve
- Pressure-relief valve
- Air-and-vacuum relief valve
- Diaphragm valve
- Pinch valve
- Rotary valve
- Butterfly valve
- Check valve
What type of valve is installed at frequent intervals in the distribution piping so that small sections of water main may be shut off for maintenance or repair?
Isolation valve
What are the two principal types of throttling valves used in a water system?
- Pressure-reducing valves
- Altitude valves
What are three types of power actuators commonly used to operate valves?
- Electric
- Hydraulic
- Pneumatic
Records on each valve’s location must include measurements from at least how many different permanent objects?
Three
It is standard to install fire hydrants on mains with diameters of _____ on larger.
a. 6 inches
b. 8 inches
c. 10 inches
d. 12 inches
6 inches
Most water systems use hydrants with two _____ -diameter nozzles and one _____ - diameter nozzle.
a. 2.0 inch; 3.0 inch
b. 2.0 inch; 4.0 inch
c. 2.5 inch; 3.5 inch
d. 2.5 inch; 4.5 inch
d. 2.5 inch; 4.5 inch
Miscellaneous use of fire hydrants
a. is never authorized.
b. is at the public’s discretion on as-needed basis.
c. is generally discouraged, but may be authorized in a controlled context.
d. is a useful way of testing hydrants indirectly.
c. is generally discouraged, but may be authorized in a controlled context.
Which of the following is NOT a common classification of fire hydrants?
a. Flow hydrant
b. Warm-climate hydrant
c. Wet-barrel hydrant
d. Dry-barrel hydrant
a. Flow hydrant
The lower barrel should be in the ground so that the connection to the upper barrel is approximately _____ above the ground line.
a. 12 inches
b. 1 inch
c. 6 inches
d. 2 inches
d. 2 inches
What type of fire hydrant is used in freezing climates?
Dry-barrel hydrant
What is an auxiliary valve used for?
Turning off the hydrant for repair or maintenance
Why is a fire hydrant operating nut five-sided?
To prevent operation by using a standard socket wrench
In what type of fire hydrant are the entire barrel and head below ground elevation?
Flush hydrant
In the standard hydrant color scheme, what color are class A hydrants?
Green
The height of water in three differently shaped tanks is 22.4 feet. Which tank will have the highest psi at the bottom?
a. The square tank
b. The rectangular tank
c. The cylindrical tank
d. It will be the same in all three tanks
d. It will be the same in all three tanks
Which of the following is the proper detention time for disinfecting a water storage tank that is filled with already chlorinated water that the free chlorine residual is 10 mg/L after proper detention time completed?
a. 4 hours
b. 6 hours
c. 8 hours
d. 24 hours
b. 6 hours
Which of the proper detention time for a water storage tank with water that is mixed with hypochlorite already in the tank such that free chlorine residual is 10 mg/L after proper detention is complete?
a. 6 hours
b. 8 hours
c. 12 hours
d. 24 hours
d. 24 hours
In what type of water storage system does water generally “float” on the system?
a. Elevated storage
b. Demand storage
c. Emergency storage
d. Operating storage
d. Operating storage
The _____ may require the installation of obstruction lights or strobe lights on an elevated tank, depending on its height and location, to warn aircraft of its vicinity.
a. Occupational Safety and Health Organization (OSHA)
b. American Water Works Association (AWWA)
c. Federal Aviation Administration (FAA)
d. Federal Communications Commission (FCC)
c. Federal Aviation Administration (FAA)
What is the result of utilizing storage to minimize pumping?
More efficient use of energy and lower operating costs
What is the term for a tank that rests on the ground and has a height that is greater than its diameter?
Standpipe
What is the term for a vertical supply pipe to an elevated tank?
Riser
Ponds, lakes, or basins are all examples of what type of raw-water storage container?
Reservoir
Which basic electrical unit is used to measure a material’s opposition to the flow of electricity?
a. Ampere
b. Ohm
c. Volt
d. Joule
b. Ohm
All sensors that respond to liquid pressure will perform poorly if _____ enter(s) the sensor.
a. air
b. corrosive chemicals from the water treatment process
c. corrosive chemicals from piping
d. iron bacteria
a. air
SCADA systems consist of what distinct components?
a. Remote terminal units (RTUs), communications, and human-machine interface (HMI)
b. Sensing instruments, RTUs, communications, and HMI
c. Sensing instruments, RTUs, communications, master station, and HMI
d. RTUs, communications, master station, and HMI
d. Remote Terminal Units (RTUs), communications, master station, and Human-Machine Interface (HMI)
What is the electronic standard range?
a. 4 to 20 mA DC
b. 4 - 20 mA AC
c. 0 to 100%
d. 0 to 1 binary
a. 4 to 20 mA DC
The D’s Arsonval meter is
a. an amperometric meter.
b. a type of pH meter.
c. an analog (uses a needle) meter.
d. a digital (number displays on unit) meter.
c. an analog (uses a needle) meter.
Which of the following is NOT an example of a secondary instrument?
a. Telemetry device
b. Multiplexing device
c. pH meter
d. indicator
c. pH meter
Secondary instrumentation transmits information of what type?
Information provided by sensors
What are two types of temperature sensors commonly connected to instrumentation?
- Thermocouples
- Thermistors
In what type of control system is each piece of equipment adjusted by the water system operator directly turning it on and off?
Direct manual control
What type of automatic control system measures a variable and adjusts the equipment proportionally?
Feedforward proportional control
What is the simplest of all AC motors?
a. Synchronous motor
b. Squirrel-cage induction motor
c. Wound-rotor induction motor
d. Split-phase motor
b. Squirrel-cage induction motor
Starters are typically used on motors
a. larger than fractional horsepower.
b. of all fractional horsepower.
c. of all horsepower ratings.
d. when gasoline in unavailable.
a. larger than fractional horsepower.
In what type of motor is power applied to the windings in such a way that a revolving magnetic field is established?
a. Synchronous motor
b. Squirrell-cage induction motor
c. Wound-rotor induction motor
d. Split-phase motor
a. Synchronous motor
Operators should check the idle speed, oil pressure, water temperature, and all other operating indicators
a. before starting the engine.
b. exactly one hour after starting the engine.
c. soon after starting the engine.
d. on an as-needed basis.
c. soon after starting the motor.
What is the maximum ambient temperature at which motors are designed to function?
104 degrees F (40 degrees C)
What type of motor is used for most large pumps?
Three-phase motors
What is the primary use of diesel engines?
Power emergency generators for pump stations and water treatment plants
How should systems ensure that engines used for emergency service will function when needed?
They should be exercised under load on a predetermined schedule
What device is used when the starting current of a motor is so high that it may damage the electrical system or deprive other operating motors of sufficient current?
Reduced-voltage controller
The “heart” of a pump is called the
a. volute case.
b. impeller.
c. motor.
d. pump.
b. impeller.
Which of the following is used to stop air leakage into the casing around a pump shaft?
a. Packing gland
b. Lantern ring
c. Seals
d. Shaft sleeves
c. Seals
Which device serves the same function as the packing?
a. Inline suction gland
b. Packing gland
c. Mechanical seal
d. Lantern ring
c. Mechanical seal
Which of the following is at the top of a stuffing box?
a. Packing gland
b. lantern ring
c. Mechanical seal
d. Seal cage
a. Packing Gland
Which assembly holds the lantern ring and packing?
a. Shaft assembly
b. Casing ring assembly
c. Packing gland casing
d. Stuffing box
d. Stuffing box
Which type of valve is used to isolate a pump on the suction side?
a. Butterfly valve
b. Globe valve
c. Gate valve
d. Ball valve
c. Gate valve
Packings are designed to
a. add lubricant to the pump shaft.
b. expand and deteriorate with normal use.
c. protect the shaft.
d. wear and deteriorate with normal use.
d. wear and deteriorate with normal use.
Why is it so important to monitor the speed of a variable-speed pump?
a. To prevent excessive temperatures from developing
b. To prevent vibrations from developing
c. To prevent speed oscillation from occurring
d. To prevent cavitation from occurring
d. To prevent cavitation from occurring
What are some disadvantages of turbine pumps?
- High initial cost
- High repair cost
- The need to lubricate support bearings within the casing
- Inability to pump water containing any suspended matter
- An efficiency that at its best, limited to a very narrow range of discharge and head conditions
What type of pump has an impeller rotating in a channel of constant cross-sectional area, which imparts mixed or radial flow to the water?
Vertical turbine pump
What type of pump uses closely meshed gears, vanes, or lobes rotating within a close-fitting chamber?
Rotary pump
To prevent excessive circulation of water between the impeller discharge and suction areas, what components are used to create a flow restriction?
Wear rings
To prevent leakage at the point where the shaft protrudes through the case, what components may be used to seal the space between the shaft and the case?
Either packing rings or mechanical seals
What type pf meter is most common for individual service lines?
Positive-displacement meter
What are the advantages of a venturi meter?
- Low friction loss
- Accurate
- Low maintenance
When are magnetic meters used?
When the flow is dirty or corrosive
How many meters can be tested on most test benches?
Multiple meters can be tested simultaneously
Positive-displacement meters _____ when they are excessively worn.
a. do not register
b. under-register
c. over-register
d. register intermittently
b. under-register
Which of the following is NOT a meter type commonly used on water systems?
a. Proportional
b. Current
c. Magnetic
d. Inverse
d. Inverse
When using turbine meters, clogging of the wheel’s blades can be prevented by installing a(n) _____ ahead of the meter.
a. venturi device
b. impeller
c. strainer
d. restrictor
c. strainer
What type of meter is used for service where daily use is relatively low, but where very high flow rates may be required in an emergency?
a. Magnetic meter
b. Detector-check meter
c. Venturi meter
d. Compound meter
b. Detector-check meter
What type of meter is used for customers that have wide variations in water use?
a. Magnetic meter
b. Detector-check meter
c. Venturi meter
d. Compound meter
d. Compound meter
One of chlorine’s advantages is that it
a. is not influenced much by pH changes.
b. does not produced chlorinated by-products.
c. has a persistent residual.
d. does not cause taste and odor problems.
c. has a persistent residual.
Chlorine gas is _____ times heavier than air.
a. 1.5
b. 2.5
c. 3.5
d. 4.5
b. 2.5
After a water storage tank has been chlorinated, which bacteriological test must prove negative before the tank is put back into service?
a. Gram-negative test
b. HPC test
c. Coliform test
d. Chloramine test
c. Coliform test
Booster chlorination is chlorine added
a. in the coagulation mixing chamber.
b. before the filters.
c. at the clearwell.
d. somewhere in the distribution system.
d. somewhere in the distribution system.
Sodium hypochlorite (NaOCL) solution is available with _____ available chlorine.
a. 2 - 5%
b. 5 - 20%
c. 25 - 50%
d. 50 - 70%
b. 5 - 20%
Chlorine cylinders hold _____ of chlorine.
a. 100 lbs (45 kg)
b. 150 lbs (68 kg)
c. 200 lbs (97 kg)
d. 350 lbs (159 kg)
b. 150 lbs (68 kg)
Why would a system need a booster chlorination station?
To maintain a more consistent chlorine residual throughout the system
What is the term for a venturi device that pulls chlorine gas into a passing stream of dilution water, forming a strong solution of chlorine and water?
Injector
In the C x T equation, what does the C represent?
A known concentration of disinfectant
What is the term for all compounds with disinfecting properties, plus any remaining uncombined chlorine?
Chlorine residual
What is the term for a chlorination method increasingly used by water treatment plants because of its relative safety (as compared to gaseous chlorine) and its ease of use?
Hypochlorination
Precipitative softening water treatment plants try to end up with distribution water that is
a. slightly scale forming.
b. moderately scale forming.
neutral.
c. neutral.
d. in equilibrium.
a. slightly scale forming.
There are two major objectives for drinking water distribution system operational policies; (1) maintain water quality from the point of entry into the distribution system to the point of use and (2)
a. keep operating expenses under budget.
b. make sure customers do not waste water.
c. educate customers about water safety.
d. maintain adequate pressure and deliver adequate flow.
d. maintain adequate pressure and deliver adequate flow.
The goal of a well-managed distribution system should be to provide water to customers’ taps that has _____ from the point of entry into the system.
a. not changed
b. gained valuable nutrients
c. decreased dramatically in pH
d. become better tasting
a. not changed
What factor generally determines the need for larger mains?
a. Fire flow requirements
b. pH concerns
c. Potability issues
d. Number of customers served
a. Fire flow requirements
Which of the following is NOT a major factor in storage facility design?
a. Preventing dead zones
b. Selecting and maintaining the correct materials of construction
c. Staying under budget to allow for design modifications
d. Providing adequate and appropriate cathodic protection to prevent or control corrosion
c. Staying under budget to allow for design modifications
Where do many distribution systems water quality problems develop?
In finished water storage facilities
What is a hydraulic system model?
A computer simulation of the behavior of physical facilities and water use within the distribution system
What may occur at pressure zone boundaries?
They may form dead-end boundaries
What should be considered when designing storage facilities?
- Inspection
- Maintenance
- Monitoring
- Mixing practices
In assessing water quality, what rule is of particular interest to distribution system operators?
Lead and Copper Rule
Samples to be tested for coliforms are collected in plastic bottles must contain
a. sodium thiocarbonate.
b. sodium thioxalate.
c. sodium thiosulfate.
d. sodium thiocyanate.
c. sodium thiosulfate.
The volume of a sample for coliform compliance is
a. 100 mL.
b. 200 mL.
c. 300 mL.
d. 0; there is no volume compliance for coliforms.
a. 100 mL.
If a water sample is not analyzed immediately for chlorine residual, it is acceptable if it is analyzed within
a. 10 minutes.
b. 15 minutes.
c. 20 minutes.
d. 30 minutes.
b. 15 minutes.
The best choice to collect a water sample from a customer’s faucet when responding to a complaint would be a
a. faucet without threads.
b. faucet that can swivel.
c. single-lever handle faucet.
d. faucet with an aerator.
a. faucet without threads.
When measuring for free chlorine residual, which method is the quickest and simplest?
a. DPD colorimetric method
b. Orthotolidine method
c. Amperometric method
d. 1, 2 nitrotoluene di-amine method
a. DPD colorimetric method
A _____ is a single-volume sample collected at one time from one place.
a. DPD colorimetric method
b. grab sample
c. random sample
d. continuous sample
b. grab sample
Under the Ground Water Rule (GWR), what type of sampling is required for larger systems for chlorine residual?
Continuous
What are three broadly classified areas from which samples are generally collected?
- Raw-water supply
- Treatment plant
- Distribution system
Consistency among laboratories in analytical results is overseen by state primacy programs and by what organization?
USEPA
If samples arrive at a laboratory past the specified holding time following collection, the laboratory must do what?
The must reject the samples
The correct protective methods for backflow-prevention devices, in order of decreasing effectiveness, are
a. air gap, vacuum breaker (VB), reduced pressure zone backflow preventer (RPZ), and double check valve assembly (DCVA).
b. air gap, VB, DCVA, and RPZ.
c. air gap, RPZ, VB, and DCVA.
d. air gap, RPZ, DCVA, and VB
d. Best to Worst =
- Air gap
- RPZ (Reduced Pressure Zone)
- Double Check Valve Assembly
- Vacuum Breaker
What is the likelihood of a swimming pool creating a cross-connection that could contaminate a potable water supply?
a. Impossible
b. Not very likely
c. Moderately likely
d. Highly likely
c. Moderately likely
What is the likelihood of a sewage pump creating a cross-connection that could contaminate a potable water supply?
a. Impossible
b. Not very likely
c. Moderately likely
d. Highly likely
d. Highly likely
What type of backflow preventer consists of two spring-loaded check valves with a pressure-regulated relief valve located between them?
a. Vacuum breaker
b. Atmospheric vacuum breaker
c. Double check valve backflow preventer
d. Reduced pressure zone backflow preventer
d. Reduced pressure zone backflow preventer
What is a utility’s first line of defense against potential legal liability in case of public health problems resulting from a cross-connection?
a. Notifying the public
b. Maintaining complete records
c. Testing backflow preventers to find problems
d. Correcting the issues found
b. Maintaining complete records
What is the best method to prevent backflow?
Air gap
How frequently do most regulations require testing of backflow-prevention devices?
Annually
Any connection between the potable water supply and a source of contamination is known as what?
Cross-connection
What are some examples of probable cross-connection sources?
- Boilers
- Cooling towers
- service sinks
What is a term for a cross-connection for which something must be done to complete the connection?
Potential cross-connection
What are some examples of probable causes of backflow?
- High-pressure boilers
- Pressurized chemical storage tanks
- Hot-water recirculation systems
Which type of maps should NOT overlap each other?
a. Index maps
b. Comprehensive maps
c. Construction maps
d. Sectional maps
d. Sectional maps
Comprehensive maps of medium to large systems generally have scales ranging from
a. 250 - 500 feet to 1 inch.
b. 500 - 1,000 feet to 1 inch.
c. 1,000 - 1,500 feet to 1 inch.
d. 1,500 - 2,000 feet to 1 inch.
b. 500 - 1,000 feet to 1 inch.
Sectional maps generally have scales ranging from
a. 50 - 100 feet to 1 inch.
b. 100 - 200 feet to 1 inch.
c. 200 - 250 feet to 1 inch.
d. 250 - 400 feet to 1 inch.
a. 50 - 100 feet to 1 inch.
A comprehensive map should be
a. compact enough to fit in a folder.
b. as large as possible.
c. as detailed as possible.
d. written in a technical language so that only engineers can read it.
b. as large as possible.
On a plan and profile drawing, what does the abbreviation EL mean?
a. English language
b. Estimate length
c. Electric
d. Elevation
d. Elevation
What type of map is also referred to as a “wall map?”
Comprehensive Map
What type of map, commonly called a plat, is a series of maps covering sections of the water system?
Sectional Map
what is the term for a computerized program used to manage data relating to geographic locations within a water system?
Automated Mapping/Facility Management/Geographic Information System (AM/FM/GIS)
If an excavation on the road requires that one of the lanes be closed and the speed limit is 25 mph (40 km/h), how many cones are required to divert traffic?
a. 6 cones
b. 9 cones
c. 13 cones
d. 15 cones
a. 6 cones
If an excavation on the road requires that one of the lanes be closed and the speed limit is 45 mph (72 km/h), how many cones are required to divert traffic?
a. 9 cones
b. 13 cones
c. 15 cones
d. 18 cones
b. 13 cones
Who is responsible for maintaining safe working conditions?
a. Upper management
b. Operations personnel
c. Supervisors
d. All water utility personnel
d. All water utility personnel
What item should be worn whenever a worker is in a trench or has someone working above them, or when they are near electrical equipment?
a. Gloves
b. A hardhat
c. Respiratory equipment
d. A reflective vest
b. A hardhat
When lifting a load that is too heavy or too large to lift comfortably,
a. get a firm hold of the object before lifting.
b. bend at the knees and lift with the legs.
c. use a mechanical device to assist in lifting heavy objects.
d. maintain good footing, with feet about shoulder width apart, while lifting.
c. use a mechanical device to assist in lifting heavy objects.
Which of the following is NOT an example of an accidental disaster that might disrupt water utilities?
a. Earthquake
b. Chemical spill
c. Fire
d. Transportation accident
a. Earthquake
What is the most common injury of distribution system workers?
Back Injury
Would a meter pit be a permit-required confined space?
Yes - It may contain a hazardous atmosphere
Under what conditions is cave-in protection always required?
All excavations at least 5 ft (1.5 m) deep
What three chemicals are commonly used to disinfect water mains and other facilities?
- Calcium hypochlorite
- Liquid chlorine
- Sodium hypochlorite
What are the basic elements to good customer relations?
- Good communication
- Caring
- Courtesy
What should meter readers do when asked a question to which they don’t know the answer?
Tell the customer that they don’t know, but will find out and get back to them.
What should customers be told when their water service must be temporarily stopped?
Notify them with enough time so that they can prepare.
_____ generally, presents the greatest exposure to the public and can have the greatest impact ensuring public confidence.
a. Formal media campaigns
b. Water distribution personnel
c. Large-scale public relations projects
d. Political campaigns
b. Water distribution personnel
_____ should be viewed as an opportunity to improve communications and build goodwill.
a. The initial customer contact
b. A response to a customer complaint
c. Every customer contact
d. A meter reading
c. Every customer contact
If damage to a customer’s property occurs,
a. customers should be told how to repair the damage.
b. customers should be put in touch with a professional who can repair the damage.
c. it is the customer’s responsibility to fix the damage.
d. the property must be restored to its original state before workers leave the site.
d. the property must be restored to its original state before workers leave the site.
Shutoffs should be scheduled
a. at the utility’s convenience.
b. during the holidays.
c. on weekends.
d. to coincide with low-water-use hours.
d. to coincide with low-water-use hours.
What is the general rule for talking to reporters?
a. Don’t do it, unless you absolutely have to
b. Keep answers brief
c. Make only positive statements
d. Validate all statements with relative statistics
a. Don’t do it, unless you absolutely have to