Questions and Answers
Which tower will register the most pressure in psi?
If the water level in Tower 1 is 118 feet, what will the pressure reading be at the base?
51.1 psi
What is the definition of potable water?
Water that does not contain objectionable pollution, contamination, or infective agents and is considered safe for drinking.
What is the first item used when installing a service line to a customer?
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If a meter to a residence is located in the basement, what should be located between the water main and the house?
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A 5/8" x 3/4" water meter serves a residence. Over a period of years the meter __________ in recording actual water used.
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To isolate part of a distribution system, what type of valve is commonly used?
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Trihalomethanes (THMs) are caused by?
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The longer the contact time water and chlorine residuals enjoy, the ________ the THM level will probably be.
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THMs should be eliminated from finished water because they cause?
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The maximum contaminant level for THMs is?
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When collecting THM samples, one sample must be taken at a site where the water has been in the distribution system the longest time.
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An applicant for a class D test who has graduated high school but has no approved training credits must have ____________ "hands on" experience.
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What type of water main is most likely to become contaminated from gasoline saturated soil?
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What type of materials must not be used as backfill for water mains?
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Nitrate in levels above _________ mg/L can cause "blue baby" disease.
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A boil order must be issued if system pressure drops below 20 psi or if contamination of any part of the system is suspected. Why?
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A boil order should be issued for?
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Upon the issuance of a boil order, the IEPA regional office should be notified of the order because ________________?
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The "C" factor of a pipe is ________________?
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The higher the "C" factor of a pipe, the _____________ the pipe and the greater the carrying capacity of the pipe.
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A distribution system that is "looped" instead of having dead ends will help prevent?
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Chlorine tablets (calcium hypochlorite) should be ________________.
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What is the definition of a water main?
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What is the minimum size of a water main required by the IEPA?
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Is a construction permit from the IEPA permit section required for the installation of a water main?
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Is a construction permit from the IEPA permit section required for the installation of a water service?
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A three-quarter inch service line is tapped on a water main. The corporation stop should be installed__________________.
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A 6 inch PVC water main is installed, what should be installed at the end of the main?
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Cathodic protection in a storage tank is?
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What is an altitude valve?
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Where is an altitude valve located?
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Disinfection is the process of?
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A device that is used to repair a cracked water main is?
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When installing permanent landmarks for the location of valves, etc., what should not be used?
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Three waterborne diseases are?
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9,500 gallons to million gallons per day (MGD)
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98,000 gallons to million gallons per day (MGD)
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678,000 gallons to million gallons per day (MGD)
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1,245,000 gallons to million gallons per day (MGD)
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.895 MGD to gallons per day
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2.20 MGD to gallons per day
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.019 MGD to gallons per day
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.999 MGD to gallons per day
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How much pressure (in psi) does 1 foot of elevation offer?
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Velocity of flow in a water main is expressed in?
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A public water supply purchases 4,500,000 gallons of water from a parent supply in a 30-day period. In the same period, the public water supply sells 3,900,000 gallons of water to its customers. What is the amount in gallons of unaccounted for water? What is the percentage of accounted for water?
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What is the industry standard for acceptable water loss in a public water supply?
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If the pH of a water sample is below seven units, it is considered?
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The average flow from a 5/8 inch x 3/4 inch water meter is _________ gpm?
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A connection between a possible water supply and a non-potable water supply is?
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New water main should be disinfected when?
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How many pounds of water are in a cubic foot of water?
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How many pounds of water is in 50,000 gallons of water?
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How many gallons of water are in a cubic foot of water?
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What is a water hammer?
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High levels of lead in potable water may cause?
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What is the required range of fluoride in mg/l to be in compliance with Illinois Department of Public Health regulations?
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Bacti samples show the absence or presence of coliform. If present, the sample contains?
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The number of bacti samples collected in a public water supply distribution system is based on?
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Routine bacti samples are collected on __________ faces at a water supply which buys its water or uses a groundwater source not under the influence of surface water.
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What type of test is commonly used for testing fluoride levels?
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What type of test is most commonly used for testing chlorine residuals in a small system or in a distribution system?
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Sodium thiosulfate is added to a bacti sample bottle to?
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Bacti sample bottle should be?
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To collect a bacti sample, the collector must be?
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When collecting a bacti sample, the lid of the sample bottle should be?
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Bacti samples must be analyzed no later than___________ hours after collection.
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Testing for THMs can be performed?
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A circuit breaker is used to?
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What is the minimum combined chlorine residual that is required to be in all parts of a distribution system?
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What is free chlorine?
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What is total chlorine?
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What is the minimum free chlorine residual that is required to be in all parts of the distribution system?
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Of these three disinfectants, which is the strongest: Calcium hypochlorite, sodium hypochlorite, or chlorine gas?
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What is the percentage of available chlorine in chlorine gas?
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What is the percentage of available chlorine in calcium hypochlorite?
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What is the percentage of available chlorine in sodium hypochlorite?
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If an operator has total chlorine residual of 1.6 mg/L and the sample has a free chlorine residual of .9 mg/L, what was the chlorine demand in the sample water?
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If calcium hypochlorite and oily rags are allowed to come into contact with each other, what will occur?
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When collecting a bacti sample, the water should be collected after the faucet has run for at least?
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Poly-pigging of a water main serves what purpose? Disinfecting the water main, sealing the inside of the main with a smooth coating, both, or neither?
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If a small public water supply pumps 3,000,000 gallons of water in a 30-day period, and its expenses total $8,770, how much does it cost this public water supply to produce 1,000 gallons of water? And is this, compared to the national average, considered high?
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An elevator water tank sits on a bluff overlooking a river valley. The water level in this tank is 144 feet above the base of the tower. A part of the distribution system serves homes along the banks of the river. These homes are 102 feet lower than the base of the water tower. What is the average system pressure in psi at these homes?
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If a home has a higher pressure than 80 psi, what should they install?
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A 4-inch water main 5,000 feet in length needs to be flushed long enough to completely change out the water in the main. How long would it take to completely flush out this line if the fire hydrant at the end of the line is flowing at a rate of 325 gallons per minute?
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What is the invert of the pipe?
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What is OSHA?
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What is a specific capacity as related to groundwater?
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What is static water level?
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What is a well casing vent?
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What is a sounding tube?
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What is a gravel tube?
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What is a pump pedestal?
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What is a pump motor base seal?
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What are sampling taps?
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What is an air-release vacuum breaker valve?
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What is a valve pump blowoff?
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What is an air line water level measuring device?
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What is the purpose of a check valve?
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Study Notes
Water Towers and Pressure
- Both water towers, 125 feet high, hold 122 feet of water; they register equal pressure in psi.
- Pressure at the base of Tower 1 (water level at 118 feet) is 51.1 psi.
Definitions and Regulations
- Potable water: safe for drinking, free from objectionable pollution or contamination.
- The corporation stop is the first item installed when connecting a service line.
- A curb stop is required between the water main and the house if the meter is in the basement.
- A boil order is necessitated by system pressure dropping below 20 psi or contamination suspicion, as regulated by the IEPA.
Water Measurement and Contaminants
- Trihalomethanes (THMs) arise from chlorinated water reacting with organic materials; higher contact time increases THM levels.
- The maximum contaminant level for THMs is .080 mg/l; they are carcinogenic and should be eliminated from finished water.
- Nitrate levels above 10 mg/L can lead to "blue baby" disease.
Water Distribution and Pipe Maintenance
- Gate valves are commonly used to isolate parts of a distribution system.
- PVC water mains are especially susceptible to contamination from gasoline-saturated soil.
- Cinders must not be used as backfill for water mains.
Water Supply and Testing
- Acceptable industry standard for water loss in public supply is 10% or less.
- Routine bacteriological samples collected monthly in water supply systems depend on served population size; presence of coliform indicates contamination.
- Free chlorine remnants must be at least 0.5 mg/l in the distribution system to ensure safe water.
Fluoride and Chlorine
- Required fluoride levels should be between 0.7 to 1.2 mg/l to comply with Illinois Department of Public Health standards.
- The strongest disinfection method among calcium hypochlorite, sodium hypochlorite, and chlorine gas is chlorine gas, with 100% available chlorine content.
Pumping and Flow
- A water hammer is the phenomenon of water movement reversing due to rapid flow changes.
- Velocity in a water main is usually expressed in feet per second; 1 foot of elevation equates to 2.31 psi of pressure.
- The average flow through a 5/8" x 3/4" water meter is between 5-7 gallons per minute.
Additional Infrastructure
- Water mains should have a minimum diameter of 4 inches as per IEPA regulations.
- An altitude valve automatically regulates flow into elevated tanks based on water level, situated beneath the water tower.
- Check valves prevent backflow, maintaining system pressure and acting as safety measures against back siphonage.
Safety and Compliance
- Materials like oily rags must be properly stored away from chlorine to avoid ignition risks.
- A small electric current known as cathodic protection prevents corrosion in storage tanks.
- Construction permits are mandatory for water main installations but not for water service installations.
Water Main Operations
- Concrete thrusting blocks should be installed at the ends of water mains; a split-sleeve clamp is used for repairing cracks in water mains.
- A pressure-reducing valve is advised for households where pressure exceeds 80 psi.
- The invert of a pipe refers to its lowest exterior point, crucial for ensuring proper drainage.
Miscellaneous
- The sound pressure and water level in a well can be monitored by specific devices, enhancing water management efficiency.
- Significant water sampling and testing methods contribute to the safety and quality of public water supplies.
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Description
Test your knowledge on hydraulic pressure in water towers and the definition of potable water. This quiz covers concepts related to pressure measurements and water quality standards. Perfect for students and professionals in fields related to hydraulics and environmental science.