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Water Distribution Exam Study Guide |
100% Correct Answers | Verified | Latest
2025 Version
Potable water may be defined as: a. Any water that occasionally may be polluted from another source b. Any water that, according to recognized standards, is safe for consumption c. Water high in organic content d. Water that has been transported from outside the service area - ✔✔b). Any water that according to recognized standard is safe for human consumption. To prevent the entry of surface contamination into a well is the purpose of: a. The well casing b. The louvers or slots c. Well development d. The sanitary seal - ✔✔d) The Sanitary Seal Pure water will exhibit a pH value of? a. 0. b. 7. c. 10. d. 14.0 - ✔✔b) 7. A pH reading of 6.0 units indicates that the water sample is:
a. Very acidic b. Slightly alkaline c. Very alkaline d. Slightly acidic - ✔✔d) Slightly Acidic In drinking water quality, "TDS" is the abbreviation for? a) Total digestable substances b) Total dissolved solids c) Time-delayed sicknesses d) Terminal diseases started - ✔✔b) Total Dissolved Solids In drinking water regulations, the abbreviation "MCL" stands for? a) Maximum contaminant level b) Multiple constituent levels c) Most common level d) Minimum considered legal - ✔✔a) Maximum contaminant level The MBAS method is used to determine levels of which of the following drinking water constituents? - ✔✔Forming Agent In water quality, the symbol "mg/L" is equivalent to: a. Micrograms per liter b. Parts per million c. Parts per billion d. Mostly good levels - ✔✔b) Parts per million
b. Hydrogen sulfide c. Methane d. Oxygen - ✔✔b) Hydrogen Sulfide The most commonly used meter on small domestic services? a. Venturi meter b. Propeller meter c. Orifice plate meter d. Nutating disc meter - ✔✔d) Nutating Disk Meter A Nutating disk is found in certain? a. Positive displacement pumps b. Main line valves c. Chemical feeders d. Water meters - ✔✔d) Water meters A pump is experiencing back-spin after it is shut down. What is the most likely cause? - ✔✔Malfunction check valve When fully open, which of the following valve types will have the highest friction loss? a. Gate valve b. Globe valve c. Ball valve d. All will have about the same friction loss. - ✔✔b) Globe valve The main purpose of a butterfly valve in a water distribution system is for? - ✔✔Isolation
The most likely means of connecting two pressure zone is through a? - ✔✔Pressure reducing valve Which of the following devices is routinely used to reduce system pressure? - ✔✔Globe valve A venture or a weir is a device that is used to? - ✔✔Measured water flow The most common valve in water distribution system is the? a. Gate valve b. Butterfly valve c. Check valve d. Globe valve - ✔✔a) Gate valve Venturi meters operate under the principle of? - ✔✔Pressure differential An auxiliary valve is always located adjacent to a? - ✔✔Fire Hydrants If you encounter a liquid chlorine leak in a one-ton container. What action should you take first, to reduce the severity of the leak? a. Apply a caustic solution b. Spray the container with water c. Spray the container with an ammonia solution d. Rotate the container to place the leak at the top - ✔✔d) Rotate the container to place the leak at the top The most commonly used water disinfectant in the United States is? a. Chlorine Dioxide
Yellow - ✔✔Gas, Oil, Stream, Petroleum, or Gasesous Materials Orange - ✔✔Communications, Alarm or Signal Lines, or Conduit Purple - ✔✔Reclaimed Water, Irrigation, and Slurry Lines Blue - ✔✔Potable Water Green - ✔✔Sewers and Drain Lines Pink - ✔✔Temporary Survey Markings White - ✔✔Proposed Excavating The presence of coliform bacteria in a distribution system? a. Is positive proof that pathogenic organisms are present b. Requires the use of brilliant green bile as a secondary disinfectant c. Indicates that pathogenic organisms may be present also d. Has no particular significance - ✔✔c) Indicates that pathogenic organisms may be present also Most below-ground-level storage tanks are constructed of? a. Fiberglass b. Steel c. Concrete d. Special composite materials - ✔✔c) Concrete
When fully open, which of the following will have the lowest friction loss? a. Gate valve b. Butterfly valve c. Globe valve d. All will have about the same friction loss. - ✔✔a) Gate valve Enclosed, open, and semi-closed are terms used for the designation and selection of? a. Impellers b. Lantern rings c. Sleeves d. Stuffing boxes - ✔✔a) Impellers "Blackflow Device" is a term used to describe a device that? a. connects three inlet lines with one outlet line b. lets air into valve vaults c. prevents backflow of potentially contaminated source into drinking water d. prevents backflow of water through an out-of-service pump - ✔✔c) Prevents backflow of potentially contaminated source into drinking water A compound meter is a device which? a. Is installed to allow automated meter reading b. Can be installed to measure water use by as many as 12 separate customers c. Provides accurate readings over a wide range of flows d. Is a typical residential water flow meter - ✔✔c) Provides accurate reading over a wide range of flows
When testing a distribution system for chlorine residual, you should? a. Test samples from several different points b. Test a sample from one point several times c. Have a sample volume of at least 100 mL which is taken back to the laboratory d. Use the ortho-tolidine method - ✔✔a) Test samples from several different points A normal buried valve located on a street water main and leading to a water service is known as a? a. Gate valve b. Corporation stop c. Altitude valve d. Auxiliary valve - ✔✔b) Corporation Stop The fusible plug that is in all chlorine containers? a. May be used as a tap for the chlorine source b. Should be removed after the cylinders are empty c. Should never be removed or tampered with d. Should be removed prior to withdrawing chlorine from the container - ✔✔c) Should never be removed or tampered with An example of a pressure-differential type water is a? a. Venturi meter b. Propeller meter c. Nutating disk meter d. Magnetic flow meter - ✔✔a) Venturi meter
The only blackflow prevention device approved for all application is the? a. Double check valve b. Triple check valve c. Reduced pressure zone device d. Pressure vacuum breaker - ✔✔c) Reduced pressure zone device A new water main should be flushed, disinfected at 50 mg/L, and held at above 25 mg/L for at least? a. 12 hours b. 24 hours c. 36 hours d. 48 hours - ✔✔b) 24 hrs A cross-connection means? a. Four pipelines tied together b. A T-shaped tool c. A connection between potable water and "unapproved" water supplies d. A connection between two or more pressure zones - ✔✔c) A connection between potable water and "unapproved" water supplies The packing gland serves many functions in a centrifugal pump. Among these, it Keeps gritty material from entering the? a. Acts as a coolant to keep the pump bearing from overheating b. Keeps gritty material from entering the packing box c. Keeps the pump primed
d. Water table - ✔✔b) Drawdown. Entry into an atmosphere with high concentrations of chlorine gas requires? a. A self-contained breathing apparatus b. An approved and uncontaminated canister mask c. Forced ventilation of the work area d. Atmospheric testing with ammonia solution prior to entry - ✔✔a) A self-contained breathing apparatus. The height to which water will rise in wells located in an artesian aquifer is called the? a. Pumping water level b. Piezometric surface c. Drawdown d. Radius of influence - ✔✔b) Piezometric Surface. Hardness in water is due to dissolved? a) Calcium and magnesium b) Sodium and potassium c) Chlorides and carbonates d) Organic matter - ✔✔a) Calcium and Magnesium. A primary drinking water regulation is based upon? a) Health effects b) Patent laws c) Appearance and aesthetic issues
d) Lowest cost of treatment - ✔✔a) Health effects. Algae growth in untreated surface water reservoirs can be reduced by applying? a) Ferric chloride b) Caustic soda c) Citric acid d) Copper sulfate - ✔✔d) Copper Sulfate. The layer of a stratified lake that is most likely to be impacted by algae is called the? a) Epilimnion b) Hypolimnion c) Thermocline d) Transition zone - ✔✔a) Epilimnion. Secondary drinking water standards are generally based upon? a) Public health impacts b) Microbiological constituents c) Organic compounds d) Aesthetic properties - ✔✔d) Aesthetic Properties. An aquifer is usually composed of? a) Sand and gravel b) Clays and silts c) Bedrock
d) 30 psi - ✔✔c) 20 psi The definition of a public water system in the Safe Drinking Water Act is a system that supplies piped water from human consumption that has at least? a) 15 service connections or serves 25 or more persons for 60 or more days a year b) 25 service connections or serves 15 or more persons for 60 or more days a year c) 15 service connections or serves 60 or more persons for 25 or more days a year d) 60 service connections or serves 15 or more persons for 25 or more days a year - ✔✔a) 15 service connections or serves 25 or more persons for 60 or more days a year Pieces of metal that are designed to corrode instead of the facility they are designed to protect are called? a) Insulated Wire b) Sacrificial anodes c) Electrolysis Test Stations d) Metallic Syncs - ✔✔b) Sacrificial anodes The federal Lead and Copper Rule requires that samples be collected? a) From the Raw Water Source b) From the Treatment Plant c) From the Distribution System d) From Residential Taps - ✔✔d) From Residential Taps The term Corrective Maintenance is? a) Work performed in response to a failure b) Work performed at the direction of a supervisor
c) Work performed to prevent failures d) Work performed as scheduled maintenance - ✔✔a) Work performed in response to a failure Any of the bacteria within the coliform bacterial group can be considered as? a) An indicator of viral contamination b) A deadly organism c) An indicator of the potential presence of pathogenic fecal organisms d) A violation of secondary health standards - ✔✔c) An indicator of the potential presence of pathogenic fecal organisms In order to preserve the ability to locate non-metallic pipes in the future new installations typically require the installation of? a) Survey monuments b) Location markers c) Radio tranmission chips d) Tracer wire - ✔✔d) Tracer wire A primary consideration in determining the number and location of sampling points in a water distribution system are that they should be? a) Representative of each source and condition within the system b) Ease of collecting the sample c) Location of the water quality lab d) The size of the water main - ✔✔a) Representative of each source and condition within the system Cathodic protection means protection against? a) Contamination
b) Issuance of Boil Water notices c) Repeat Sampling d) Distribution system flushing - ✔✔c) Repeat Sampling The metal component that is protected from corrosion is called the? a) Cathode b) Anode c) Rectifier d) Electron - ✔✔a) Cathode The performance curve of a pump reflects? a) Pump capacity b) Pump efficiency c) Pump horsepower d) All of the above - ✔✔d) All of the above As flow increases, friction losses in a water distribution pipeline? a) Decrease b) Remain the same c) Increase d) Can increase or decrease - ✔✔c) Increase What is the difference between a primary standard and a secondary standard? a) Primary standards refer to substances that are carcinogenic; secondary standards do not.
b) Primary standards refer to substances that are thought to pose a threat to human health; secondary standards refer to aesthetic water quality c) Primary standards refer to substances that, if not put in check, will eventually kill humans; secondary standards do not. d) Secondary qualities refer to contaminants that will only make some people sick, while primary standards refer to substances that will make everyone sick. - ✔✔b) Primary standards refer to substances that are thought to pose a threat to human health; secondary standards refer to aesthetic water quality Which of the following devices can be used to measure distribution system pressure over a period of time? a) Pressure Recorder b) Pressure Gauge c) Pressure Transducer d) Pressure Meter - ✔✔a) Pressure Recorder With ductile-iron pipe, the best joint to use when the installation is aboveground where rigidity is required, such as in water treatment plants and pumping stations, is a? a) Mechanical Joint b) Flanged joint c) Restrained Joint d) Grooved and shouldered Joint - ✔✔b) Flanged joint A pump assembly where the impeller is mounted directly on the shaft of the motor driving the pump is referred to as? a) Close coupled b) Frame Mounted c) Shaft Driven d) Mixed Axial - ✔✔a) Close coupled
