Download AWWA ABC Water Distribution Grades 1 & 2| Questions With Verified Solutions|2025/2026 and more Exams Water and Wastewater Engineering in PDF only on Docsity!
AWWA ABC Water Distribution
Grades 1 & 2
What type of meter is most common for individual service lines? - โ โ positive displacement metes
What are the advantages of a venturi meter? - โ โ low friction loss, accurate, low maint.
When are magnetic meters used? - โ โ when flow is dirty or corrosive
How many meters can be tested on most test benches? - โ โ Multiple
Meter not commonly used on water systems? - โ โ Inverse
Positive-displacement meters_________ when they are excessively worn. - โ โ Underregister
Samples to be tested for coliforms are collected in plastic bottles that must contain? - โ โ Sodium thiosulfate
The volume of a sample for coliform compliance is? - โ โ 100 mL
If a water sample is not analyzed immediately for chlorine residual, it is acceptable if it is analyzed within? - โ โ 15 min
The best choice to collect a water sample from a customer's faucet when responding to a complaint would be a? - โ โ faucet without threads
When measuring for free chlorine residual, which method is the quickest and simplest? - โ โ DPD colorimetric method
A __________ is a single-volume sample collected at one time from one place. - โ โ Grab sample
Under the ground water rule (GWR), what type of sampling is required for larger systems for chlorine residual? - โ โ continuous
What are all three broadly classified areas from which samples are generally collected? - โ โ Raw water supply, treatment plant, and distribution system
Consistency among laboratories in analytical results is overseen by state primacy programs and by which organization? - โ โ USEPA
Likely cause of vibration in a existing pump/motor installation - โ โ Bad bearing, imbalance of rotating elements, misalignment from shifts in underlying foundation.
chlorine demand is satisfied at the point when - โ โ the reaction of chlorine with organic and inorganic materials stop
What chlorine concentration should be produced when disinfecting a well or well pump? - โ โ 50 mg/l
Chlorine will destroy bacteria most rapidly at what pH? - โ โ 7.
Compression fittings used with copper or plastic tubing seal by means of - โ โ a compressed beveled gasket
Water meter pits are usually used in - โ โ cold climates
Which type of valve would be best to use to precisely throttle flow? - โ โ Needle valve
Which type of valve is used to isolate a pump on the suction side? - โ โ Gate Valve
When fully opened, which type of valve will have the highest head loss?
Which type of valve will prevent the collapse of a pipe? - โ โ Air- and-vacuum relief valve
valves used in water systems - โ โ Gate, globe, pressure-relief, air- and vacuum relief, diaphragm, pinch, rotary, butterfly, check.
What type of valve is installed at frequent intervals in distribution piping so that small sections of water main may be shut off for maintenance or repair? - โ โ Isolation Valve
What are the two principal types of throttling valves used in a water system? - โ โ Pressure-reducing valves and altitude valves
What are the three types of power actuators commonly used to operate valves? - โ โ Electric, hydraulic, and pneumatic
Records of each valve's location must include measurements from at lest how many different permanent reference objects? - โ โ Three
It is standard practice to install fire hydrants on mains with diameters of ____________ or larger. - โ โ 6 in.
Most water systems use hydrants with two _________ diameter nozzles and one ________ diameter nozzle. - โ โ 2.5 in ; 4.5 in
Miscellaneous use of fire hydrants - โ โ is generally discouraged but may be authorized in a controlled context.
The following is NOT a common classification of fire hydrants - โ โ Flow Hydrant
The lower barrel should be buried in the ground so that the connection to the upper barrel is approximately __________ above the ground line. - โ โ 2 in
What type of fire hydrant is used in freezing climates? - โ โ Dry- barrel Hydrant
What is the auxiliary valve used for? - โ โ Turning off the hydrant for repair or maintenance
Why is a fire hydrant operating nut five sided? - โ โ To prevent operation using a standard socket wrench
In what type of fire hydrant are the entire barrel and head below ground elevation? - โ โ Flush Hydrant
In the standard hydrant color scheme, what color are class A hydrants?
The Height of water in three differently shaped tanks is 22.4 Feet. Which tank will have the highest psi at the bottom? - โ โ 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 such that the free chlorine residual is 10 mg/L after the proper detention time is completed? - โ โ 6 Hours
Foot valves are a special type of? - โ โ Check valve
Which type of valve would be the best to use to precisely throttle flow?
Which type of valve is used to isolate a pump on the suction side? - โ โ Gate valve
When fully open which valve will have the highest head loss? - โ โ Globe valve
Which type of valve will prevent the collapse of a pipe? - โ โ Air- and-vacuum relief valve
Which basic electrical unit is used to measure a material's opposition to the flow of electricty? - โ โ Ohm
SCADA systems consist of what distinct components? - โ โ RTUs, communications, master station, and HMI
What is the electronic standard range? - โ โ 4 to 20 mA DC
The D'Arsonval meter is? - โ โ An analog (uses a needle) meter
not an example of a secondary instrument? - โ โ pH monitor
Instruments that display information provided by sensors? - โ โ Secondary instrumentations
The "heart" of a pump is called the? - โ โ Impeller
Which agency sets legal limits on the concentration levels of harmful contaminants in potable water distributed to customers? - โ โ US Environmental Protection Agency
The number of monthly distributions system bacteriologiacal samples required is - โ โ Based on the population served
What is the maximum contaminant level for total trihalomethanes (TTHM) in the united States? - โ โ 0.080 mg/L
Under the Surface Water Treatment Rule, disinfection residuals must be collected at the same location in the distribution system as - โ โ coliform samples
Iron can cause "red water" and thus customer complaints when its concentration is above its secondary maximum contaminant level of - โ โ 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. - โ โ State
What is the objective of Total Coliform Rule? - โ โ 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 contaminants in drinking water? - โ โ EPA
Explain the difference between the different tiers of violations. Which tier is the most serious? - โ โ Tier 1 = 24 hours (most severe)
Tier 2= 30 days
Tier 3= 1 year
Riparian doctrine is sometimes called the "rule of - โ โ reasonable sharing."
During which season is water typically the highest? - โ โ summer
Of the common types of distribution system, which type is considered least desirable? - โ โ Tree system
The velocity of water is calculated as the quantity of water that flows through a pipe - โ โ divided by the cross-sectional area of pipe
What is the term for water pressure in a main or in a container that is measured by a gauge? - โ โ Gage pressure
In hydraulics, how is head expressed? - โ โ ft-pounds per pound
What is the term for pressure measured in terms of the height of water ( in meters or feet)? - โ โ Head
What are three types of head? - โ โ Elevation head
velocity head
pressure head
The highest degree of protection for the exterior of a coating steel pipe is - โ โ Cathodic protection
The C value is a measure of a pipe wall's - โ โ roughness, which retards flow due to friction.
Type of joint for ductile iron piping? - โ โ Push-on joint
What is the term for a sudden repeated increase and decrease in pressure that continues until dissipated by friction losses? - โ โ Water Hammer
Not a type of joint generally used today for connecting DIP and fittings?
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? - โ โ External Load
What term refers to the process by which organic compounds pass through plastic pipe? - โ โ Permeation
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? - โ โ Reinforced concrete cylinder pipe
When PVC pipe is stacked loose, it should not be stacked more than how high? - โ โ 3.0 feet
What is the most common cause for pipe joint failure (leaking) in newly laid pipe? - โ โ Not having the joint completely clean
The backfill material for a pipe installation should contain enough _____________ to allow for through compaction. - โ โ Moisture
What is the approximate angle of repose for average soils when using the sloping method for the prevention of cave-ins? - โ โ 1.0:1.
true or false Always store gaskets in a clean, secure location until they are needed. - โ โ True
How deep should the compacted covering layer be for pipe less than 8 in. in diameter? For pipe larger than 8 in. in diameter? - โ โ 6- in., 12-24 in.
How must a pipeline be prepared before a sample is taken for bacteriological testing? - โ โ A pipeline must be flushed of chlorinated water and refilled with water from the system.
What term refers to the process of repeatedly pushing a pressurized water pipe vertically to the near the bottom of the loose fill at intervals along the excavation? - โ โ Jetting
A corporation stop is used for a - โ โ service line
Which device serves the same functions as the packing? - โ โ Mechanical seal
Which of the following is used to stop air leaking into the casing around the pump shaft? - โ โ Seals
Which of the following is at the top of a stuffing box? - โ โ Packing gland
Which assembly holds the lantern ring and packing? - โ โ Stuffing box
Which type of valve is used to isolate a pump on the suction side? - โ โ Gate valve
Packing is designed to - โ โ wear and deteriorate with normal use
Why is it so important to monitor the speed of a variable-speed pump?
- โ โ to prevent cavitation from occurring
list three disadvantages of turbine pumps - โ โ 1.high initial cost
- high repair cost
- inability to pump water containing any suspended matter
Which type of pump has an impeller rotating in a channel of constant cross-section area, which imparts mixed or radial flow to the water? - โ โ vertical turbine pump
What type of pump uses closely meshed gears, vanes, or lobe rotating within a close-fitting chamber? - โ โ Rotary pump
to prevent excessive circulation of water between the impeller discharge and suction areas, what components are used to create a flow restriction? - โ โ 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? - โ โ Either packing rings or mechanical seals
