1.
When Collecting a distribution system sample for bacteriological testing, the person collecting the sample should allow the water to run ____ before filling the sample bottle.
Correct Answer
A. As long as necessary to permit clearing of the service line
Explanation
When collecting a distribution system sample for bacteriological testing, it is important for the person collecting the sample to allow the water to run as long as necessary to permit clearing of the service line. This is because the water in the service line may contain stagnant water or sediments that could potentially contaminate the sample. By allowing the water to run until it clears, any potential contaminants can be flushed out, ensuring a more accurate and representative sample for testing.
2.
The Volume of a Cylinder with a radius of 5ft and a height of 8 ft is ___ cubic FT
Correct Answer
D. 628
Explanation
Volume of a cylinder from radius = P(pie = 3.14) X Radius square (Radius X Radius) X height
= 3.14 X (5ft radius X 5ft radius) X 8 ft high
= 3.14 X 25 ft square X 8ft high = 628 Cubic Feet
3.
The volume of a 100FT diameter tank that is 12ft deep is ____ Cubic FT
Correct Answer
A. 94,200
Explanation
Volume of a cylinder from diameter = .785 X diameter square(diameter X Diameter) X depth
= .785 X (100 ft diameter X 100ft diameter) X 12ft deep
= .785 X 10,000 square ft X 12 ft = 94,200 Cubic feet
4.
A chemical commonly used to raise pH is
Correct Answer
D. Lime
Explanation
Lime is commonly used to raise the pH level in various applications, such as in water treatment, agriculture, and gardening. It is an alkaline substance that reacts with acidic components, neutralizing them and increasing the pH level. Lime is often added to acidic soils to make them more suitable for plant growth by reducing soil acidity. Additionally, lime is used in water treatment processes to raise the pH level and reduce acidity, making the water less corrosive and more suitable for consumption.
5.
Black stains on plumbing fixtures might be attributed to
Correct Answer
D. Manganese
Explanation
Black stains on plumbing fixtures might be attributed to manganese. Manganese is a naturally occurring element that can be present in water sources. When water containing manganese comes into contact with plumbing fixtures, it can react and form black stains. This is especially common in areas with high levels of manganese in the water supply.
6.
One Kilogram equals ____ grams
Correct Answer
C. 1000
Explanation
The metric system is based on powers of ten, which means that each unit is ten times larger or smaller than the one before or after it. In this case, one kilogram is equal to 1000 grams because the prefix "kilo-" means "thousand." Therefore, to convert from kilograms to grams, we multiply the number of kilograms by 1000.
7.
The indicator organisms used to determine contamination of drinking water are
Correct Answer
A. Coliform group
Explanation
The coliform group of organisms is used as an indicator to determine the contamination of drinking water. This group includes bacteria such as Escherichia coli, which are commonly found in the intestines of warm-blooded animals. If coliform bacteria are present in drinking water, it suggests that there may be fecal contamination and the potential presence of other harmful pathogens. Therefore, monitoring the levels of coliform bacteria is an important way to assess the safety and quality of drinking water.
8.
The packing around the shaft of a centrifugal pump should be
Correct Answer
D. Tightened just enough to allow an occasional drop of liquid to escape
Explanation
The packing around the shaft of a centrifugal pump should be tightened just enough to allow an occasional drop of liquid to escape. This is because if the packing is too loose, excessive leakage can occur, leading to wastage of liquid and potential damage to the pump. On the other hand, if the packing is too tight, it can cause excessive friction, leading to overheating and premature wear of the packing material. Therefore, maintaining a slight leakage ensures proper lubrication and cooling of the packing, while minimizing leakage and avoiding excessive wear.
9.
The chemical symbol for iron is
Correct Answer
C. Fe
Explanation
The correct answer is Fe because Fe is the chemical symbol for iron. Chemical symbols are shorthand representations of elements, and Fe is derived from the Latin word for iron, "ferrum."
10.
One pound per square inch of pressure will raise water ____ Feet
Correct Answer
A. 2.31
Explanation
The answer is 2.31. This is because 1 pound per square inch (psi) of pressure will raise water to a height of 2.31 feet. This is a commonly used conversion factor in fluid dynamics and is derived from the relationship between pressure and the height of a fluid column.
11.
Static head is defined as the
Correct Answer
B. Pressure due to depth or elevation of the water
Explanation
Static head is defined as the pressure due to the depth or elevation of the water. In other words, it is the potential energy of the water at a certain point in a system. This pressure is caused by the weight of the water above that point, and it remains constant as long as there are no changes in elevation or depth. The other options, energy of motion of the water and pressure loss in the line due to friction, are not correct definitions of static head.
12.
What is the volume of a settling tank 100ft long, 25ft wide, and 8ft deep?
Correct Answer
B. 20,000 cubic feet
Explanation
Volume of a rectangle = Length X Width X depth
= 100ft X 25ft X 8ft = 20,000 cubic feet
13.
What is used to detect chlorine leaks ?
Correct Answer
B. 10 percent solution of ammonia hydroxide
Explanation
A 10 percent solution of ammonia hydroxide is used to detect chlorine leaks. Ammonia reacts with chlorine to form a white cloud of ammonium chloride, which is visible and indicates the presence of chlorine gas. This solution is commonly used in industries where chlorine is used or stored, such as water treatment plants or chemical manufacturing facilities, to quickly identify leaks and take necessary safety measures.
14.
The pressure gauge reading at the base of a tank filled to a depth of 1 ft is ___ PSI
Correct Answer
C. 0.433
Explanation
1 psi = 2.31 ft dividing your pressure by footage gives you the per food pressure.
1/2.31 = 0.4329 rounded up to .433
15.
The multiple tube fermentation test consists of three distinct tests. These tests, in the order performed, are the
Correct Answer
C. Presumptive, confirmed and completed tests
Explanation
The correct answer is "Presumptive, confirmed and completed tests". The multiple tube fermentation test is a series of tests used to detect the presence of coliform bacteria in water samples. The presumptive test is the first step, where lactose fermentation is observed to determine the presence of coliforms. The confirmed test is performed to confirm the presence of coliforms by using specific media and biochemical tests. Finally, the completed test is conducted to determine the presence of E. coli, a specific type of coliform bacteria. Therefore, the correct order of the tests in the multiple tube fermentation test is presumptive, confirmed, and completed.
16.
Chlorine gas is
Correct Answer
D. Denser than air.
Explanation
Chlorine gas is denser than air because it has a higher density compared to the density of air. This means that chlorine gas will sink and settle at the bottom when released in an open environment.
17.
Polyphosphates may be used in water treatment to retard corrosion and
Correct Answer
B. Calcium scale
Explanation
Polyphosphates are commonly used in water treatment to prevent the formation of calcium scale. Calcium scale refers to the buildup of calcium deposits on surfaces, such as pipes and fixtures, which can restrict water flow and reduce the efficiency of water treatment equipment. By using polyphosphates, the formation of calcium scale can be inhibited, helping to maintain the performance and longevity of water treatment systems.
18.
Calcium hypochlorite is formulated as a
Correct Answer
D. Powder
Explanation
Calcium hypochlorite is formulated as a powder. Powdered form is commonly used for calcium hypochlorite because it is easier to handle and store compared to other forms such as gas or liquid. Powdered calcium hypochlorite can be easily dissolved in water to create a solution that can be used as a disinfectant or sanitizer. Additionally, the powder form allows for precise measurement and control of the amount of calcium hypochlorite used, making it a convenient choice for various applications such as water treatment and swimming pool maintenance.
19.
Chlorine leaks in metal container tend to
Correct Answer
A. Become larger
Explanation
Chlorine leaks in a metal container tend to become larger because chlorine is a highly reactive gas. It readily reacts with metals, causing corrosion and weakening the container's structure. As the corrosion progresses, the leaks gradually increase in size, allowing more chlorine to escape. This can be dangerous as chlorine is toxic and can cause respiratory problems and other health issues. Therefore, it is important to address and fix chlorine leaks promptly to prevent them from becoming larger and posing a greater risk.
20.
Determining the pH of water is one of the important test of water quality. The results of the pH test indicate the
Correct Answer
B. Hydrogen ion activity
Explanation
Determining the pH of water is important for assessing its quality. The pH test measures the concentration of hydrogen ions in the water, which indicates its acidity or alkalinity. The hydrogen ion activity is a measure of how many hydrogen ions are present in the water, and it is used to determine the water's pH level. Therefore, the correct answer is hydrogen ion activity.
21.
Leakage from a packing gland should be approximately
Correct Answer
B. One drop per second
Explanation
Leakage from a packing gland should be approximately one drop per second. This is because a packing gland is used to prevent leakage in a system, such as a pipe or valve. If there is excessive leakage, it can indicate a faulty or worn-out packing gland, which needs to be repaired or replaced. Therefore, the ideal leakage rate is minimal, and one drop per second is considered an acceptable level of leakage.
22.
A chlorine cylinder valve is thought to be leaking. If ammonia vapor is passed near the valve, the presence of a leak would be indicated by
Correct Answer
D. White smoke
Explanation
Passing ammonia vapor near a chlorine cylinder valve can cause a reaction between chlorine and ammonia, resulting in the formation of white smoke. This reaction is known as the ammonium chloride smoke test and is commonly used to detect leaks in chlorine systems. The white smoke indicates the presence of a leak, as the reaction produces solid particles of ammonium chloride that appear as a visible white smoke.
23.
If a fire hydrant requires a nozzle pressure of 100 PSI, what head of water must be used to supply it?
Correct Answer
A. 231 ft
Explanation
1PSI = 2.31 ft
so multiply 2.31 ft per psi by needed psi
2.31*100=231
24.
A water main should be disinfected
Correct Answer
C. After the pipe is laid in place
Explanation
The correct answer is after the pipe is laid in place. Disinfecting the water main after it is laid in place ensures that any potential contaminants or bacteria that may have entered the pipe during construction or transportation are eliminated. This step is crucial to ensure the safety and quality of the water supply before it is put into use. Disinfecting the pipe in the storage yard, after delivery to the job site, or at the manufacturer's plant would not address the potential contamination that could occur during the installation process.
25.
Carbon dioxide in water will
Correct Answer
C. Lower pH
Explanation
When carbon dioxide dissolves in water, it forms carbonic acid. This carbonic acid lowers the pH of the water, making it more acidic. Therefore, the correct answer is "lower pH."
26.
A pneumatic ejector lifts water from low points to higher levels. The device used to achieve this is a(n)
Correct Answer
A. Air compressor
Explanation
An air compressor is used to generate compressed air, which is then used to power the pneumatic ejector. The compressed air creates pressure that lifts the water from low points to higher levels. Therefore, an air compressor is the device used to achieve this task.
27.
Pressure is commonly measured in
Correct Answer
D. Pounds per square inch
Explanation
Pressure is commonly measured in pounds per square inch (psi) because it provides a convenient unit for measuring the force exerted by a fluid or gas on a given area. The pound is a unit of force, and the square inch represents the area over which the force is distributed. This measurement is widely used in various industries, such as engineering, physics, and meteorology, to quantify and compare pressure levels. It allows for easy conversion between different units of pressure and is a standard unit in many countries.
28.
Mechanical seals are being installed in pumps because
Correct Answer
A. Packing requires an undesirable leakage that seals eliminate
Explanation
Mechanical seals are being installed in pumps because packing, which is an alternative sealing method, tends to have undesirable leakage. Mechanical seals eliminate this leakage by providing a more effective and reliable sealing solution.
29.
Which one of the following items must be replaced when connecting a new chlorine cylinder?
Correct Answer
B. Fiber washer
Explanation
When connecting a new chlorine cylinder, the fiber washer must be replaced. The fiber washer is a crucial component that forms a tight seal between the cylinder and the connection point. Replacing the fiber washer ensures that there are no leaks or gas escaping from the connection, which is important for safety reasons.
30.
A major cause of pump and motor shaft coupling wear is a
Correct Answer
C. Misalignment between pumps and motor flanges.
Explanation
Misalignment between pumps and motor flanges can cause excessive wear on the pump and motor shaft coupling. When the pumps and motor flanges are not properly aligned, it creates uneven pressure and stress on the coupling, leading to accelerated wear and potential failure. This misalignment can occur due to various reasons such as improper installation, vibrations, or thermal expansion. It is important to ensure proper alignment during installation and regularly inspect and maintain the alignment to prevent coupling wear.
31.
Filters in a water treatment process are primarily for removing or reducing
Correct Answer
D. Turbidity
Explanation
Filters in a water treatment process are primarily used to remove or reduce turbidity. Turbidity refers to the cloudiness or haziness of water caused by suspended particles such as sediment, clay, or organic matter. These particles can make the water appear dirty and can also affect its taste and smell. By passing the water through a filter, these particles are trapped and removed, resulting in clearer and cleaner water.
32.
A water treatment plant receives an average flow of 261 gpm. What is the daily total flow at the plant?
Correct Answer
B. .38 mgd
Explanation
261 gpm * 60 minutes in a hour = 15,660 gph * 24 hours per day = 375,840 gpd / 1 million = .37584 mgd rounded to .38 mgd
33.
The free chlorine residual in water is the amount of
Correct Answer
D. Uncombined chlorine that remains in the water after the chlorine has been applied and allowed to react.
Explanation
The free chlorine residual in water refers to the uncombined chlorine that remains in the water after the chlorine has been applied and allowed to react. It is measured in milligrams per liter and indicates the amount of chlorine that is still present in the water and available for disinfection purposes. This residual chlorine helps to ensure that the water remains safe and free from harmful bacteria and pathogens.
34.
The chemical name for muriatic acid is
Correct Answer
C. Hydrochloric acid
Explanation
The correct answer is hydrochloric acid. Muriatic acid is another name for hydrochloric acid, which is a strong, corrosive acid commonly used in various industries and household cleaning products. It is produced by dissolving hydrogen chloride gas in water and is known for its strong acidic properties. Sulfuric acid, phosphoric acid, and carbonic acid are different types of acids with their own chemical compositions and properties.
35.
A chlorine residual in water can be determined by using the reagent
Correct Answer
A. Diethyl-p-pHjenylenediamne (DPD)
Explanation
Diethyl-p-phenylenediamine (DPD) is a reagent commonly used to determine the chlorine residual in water. It reacts with chlorine to form a colored compound, which can be measured using a colorimeter or spectrophotometer. This method is widely used in water treatment processes and pool maintenance to ensure that the chlorine levels are within the desired range for disinfection purposes. Therefore, DPD is the correct reagent for determining chlorine residual in water.
36.
The most important use of chlorine in water treatment is as a(n)
Correct Answer
C. Disinfectant
Explanation
Chlorine is widely used as a disinfectant in water treatment because it effectively kills bacteria, viruses, and other harmful microorganisms present in the water. It helps in preventing the spread of waterborne diseases and ensures that the water is safe for consumption. Chlorine is able to penetrate the cell walls of microorganisms and disrupt their metabolic processes, leading to their inactivation. Additionally, chlorine has a residual effect, meaning it remains in the water to provide continued protection against recontamination as the water travels through the distribution system.
37.
What is the approximate volume in gallons occupied by 15,000 cubic feet of water?
Correct Answer
B. 112,200 gallons
Explanation
7.48 gal to 1 cu ft so... 15,000 cu ft X 7.48 gal per cu ft = 112,200 gallons of water in 15,000 cubic feet.
38.
The difference between the amount of chlorine added to water and the amount of residual chlorine remaining at the end of a specified contact period is
Correct Answer
D. Chlorine demand.
Explanation
The term "chlorine demand" refers to the difference between the amount of chlorine added to water and the amount of residual chlorine remaining after a specified contact period. It represents the amount of chlorine that is consumed or used up by the water to disinfect it. This measurement is important in determining the appropriate dosage of chlorine needed to effectively treat the water and ensure that a sufficient amount of residual chlorine remains to maintain its disinfecting properties.
39.
Water that requires a large amount of soap to produce an acceptable lather is termed
Correct Answer
B. Hard
Explanation
Hard water contains high levels of minerals such as calcium and magnesium. These minerals react with soap, forming insoluble compounds that reduce its effectiveness. As a result, more soap is required to produce a satisfactory lather.
40.
A pump may be damaged if it is started with the discharge valve closed, it the pump is a(n)
Correct Answer
B. Positive-displacement pump
Explanation
A positive-displacement pump operates by trapping a fixed amount of fluid and then forcing it into the discharge pipe. If the discharge valve is closed when the pump is started, the fluid has nowhere to go and pressure builds up rapidly within the pump. This can cause damage to the pump components, such as seals, valves, or the pump casing, due to the excessive pressure. Therefore, starting a positive-displacement pump with the discharge valve closed can lead to pump damage.
41.
Prepared water sample bottles used for collecting samples for bacteriological examination contain sodium thiosulfate crystals. It is important not to rinse out the sample bottle because the sodium thiosulfate
Correct Answer
D. Neutralizes any chlorine present in the sample
Explanation
Sodium thiosulfate in the prepared water sample bottles neutralizes any chlorine present in the sample. Chlorine is often added to water as a disinfectant, but it can interfere with bacteriological examination. By neutralizing the chlorine, the sodium thiosulfate ensures that the sample is not contaminated and accurate results can be obtained.
42.
Velocity of flow in water mains is usually expressed in terms of
Correct Answer
A. Feet per second
Explanation
Velocity of flow in water mains is usually expressed in terms of feet per second because it is a commonly used unit for measuring the speed of fluid flow. Feet per second provides a clear and easily understandable measurement of how quickly water is moving through the pipes. It is a practical unit for engineers and technicians to assess the efficiency and performance of the water distribution system, as well as to determine the pressure and flow rates in the mains.
43.
A pH reading of 6.0 in raw water indicates the sample is
Correct Answer
A. Acid
Explanation
A pH reading of 6.0 indicates that the sample is slightly acidic. The pH scale ranges from 0 to 14, with 7 being neutral. Anything below 7 is considered acidic, and as 6.0 is below 7, it falls into the acidic range.
44.
The tempurature of water in a stream is 10 degrees Celsius. What is the equivalent temperature in degrees Fahrenheit?
Correct Answer
C. 50 F
Explanation
the formula for Celsius to Fahrenheit is (c)*1.8+32 = (10*1.8)+32 = 50
45.
A grab sample represents
Correct Answer
A. The quality of water at the time the sample was taken.
Explanation
A grab sample represents the quality of water at the time the sample was taken. This means that the sample provides information about the condition of the water at the specific moment it was collected. It does not necessarily reflect the overall quality of the water source over a period of time. Grab samples are commonly used to assess the immediate characteristics and properties of water, such as its chemical composition or the presence of pollutants, at a specific location and time.
46.
The pH scale runs from
Correct Answer
A. 0 - 14
Explanation
The pH scale is a measure of the acidity or alkalinity of a solution. It ranges from 0 to 14, with 0 being the most acidic and 14 being the most alkaline. A pH of 7 is considered neutral, indicating a balanced concentration of hydrogen ions and hydroxide ions. Therefore, the correct answer is 0 - 14, as it correctly represents the full range of the pH scale.
47.
Five gallons of water weigh ______ LB
Correct Answer
C. 41.7
Explanation
8.34 lb for 1 gallon of water so 5 gallons * 8.34 lb per gallon = 41.7lbs
48.
What is the approximate weight, in pounds, of 50,000 gal of water?
Correct Answer
D. 417,000 lb
Explanation
8.34 lbs per gallon so... 50,000 gallons and 8.34 lbs = 50,000*8.34= 417,000
49.
The flow is 35,000 gpd. this is _____MGD.
Correct Answer
B. .035
Explanation
35,000 gpd /1 million = .035
50.
The most important factor affecting the useful life of piping is
Correct Answer
A. The ability of the material used to resist internal and external corrosion
Explanation
The ability of the material used to resist internal and external corrosion is the most important factor affecting the useful life of piping. Corrosion can significantly weaken the structural integrity of the pipe, leading to leaks, failures, and reduced lifespan. Piping materials that are resistant to corrosion, such as stainless steel or corrosion-resistant alloys, are preferred in order to ensure the longevity and reliability of the piping system.