Hydraulic Pressure and Potable Water Quiz

Questions and Answers

Which tower will register the most pressure in psi?

Both are equal (correct)

Tower 2

Tower 1

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?

Corporation stop Signup and view all the answers

If a meter to a residence is located in the basement, what should be located between the water main and the house?

Curb stop Signup and view all the answers

A 5/8" x 3/4" water meter serves a residence. Over a period of years the meter __________ in recording actual water used.

Decreases Signup and view all the answers

To isolate part of a distribution system, what type of valve is commonly used?

Gate valve Signup and view all the answers

Trihalomethanes (THMs) are caused by?

Reaction of chlorinated water with organic materials found in surface water sources. Signup and view all the answers

The longer the contact time water and chlorine residuals enjoy, the ________ the THM level will probably be.

Higher Signup and view all the answers

THMs should be eliminated from finished water because they cause?

Cancer Signup and view all the answers

The maximum contaminant level for THMs is?

.080 mg/l Signup and view all the answers

When collecting THM samples, one sample must be taken at a site where the water has been in the distribution system the longest time.

True Signup and view all the answers

An applicant for a class D test who has graduated high school but has no approved training credits must have ____________ "hands on" experience.

6 months Signup and view all the answers

What type of water main is most likely to become contaminated from gasoline saturated soil?

PVC Signup and view all the answers

What type of materials must not be used as backfill for water mains?

Cinders Signup and view all the answers

Nitrate in levels above _________ mg/L can cause "blue baby" disease.

10 Signup and view all the answers

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?

It is a regulation of the IEPA, and to protect the health of water consumers. Signup and view all the answers

A boil order should be issued for?

Until further notice Signup and view all the answers

Upon the issuance of a boil order, the IEPA regional office should be notified of the order because ________________?

It's a state regulation Signup and view all the answers

The "C" factor of a pipe is ________________?

The smoothness of the interior of a pipe Signup and view all the answers

The higher the "C" factor of a pipe, the _____________ the pipe and the greater the carrying capacity of the pipe.

Smoother Signup and view all the answers

A distribution system that is "looped" instead of having dead ends will help prevent?

Tastes and odors, "dirty" water, and chlorine depletion. Signup and view all the answers

Chlorine tablets (calcium hypochlorite) should be ________________.

Glued to the top of each section Signup and view all the answers

What is the definition of a water main?

Any line that passes one property to reach another parcel of property. Signup and view all the answers

What is the minimum size of a water main required by the IEPA?

4 inches in diameter Signup and view all the answers

Is a construction permit from the IEPA permit section required for the installation of a water main?

False Signup and view all the answers

Is a construction permit from the IEPA permit section required for the installation of a water service?

False Signup and view all the answers

A three-quarter inch service line is tapped on a water main. The corporation stop should be installed__________________.

At an angle between the top and side of the main Signup and view all the answers

A 6 inch PVC water main is installed, what should be installed at the end of the main?

Concrete thrusting block Signup and view all the answers

Cathodic protection in a storage tank is?

A small electric current used to prevent rust, corrosion, and pitting of metal surfaces. Signup and view all the answers

What is an altitude valve?

A valve that automatically shuts off the flow into an elevated tank when the water level in the tank reaches a predetermined level. The valve automatically opens when the pressure in the distribution system drops the pressure in the tank. Signup and view all the answers

Where is an altitude valve located?

Beneath the water tower Signup and view all the answers

Disinfection is the process of?

Killing or inactivating most micro-organisms in water, essentially all pathogenic bacteria. Signup and view all the answers

A device that is used to repair a cracked water main is?

Split-sleeve clamp Signup and view all the answers

When installing permanent landmarks for the location of valves, etc., what should not be used?

Trees Signup and view all the answers

Three waterborne diseases are?

Typhoid, infectious hepatitis, and cholera. Signup and view all the answers

9,500 gallons to million gallons per day (MGD)

.0095 MGD Signup and view all the answers

98,000 gallons to million gallons per day (MGD)

.098 MGD Signup and view all the answers

678,000 gallons to million gallons per day (MGD)

.678 MGD Signup and view all the answers

1,245,000 gallons to million gallons per day (MGD)

1.245 MGD Signup and view all the answers

.895 MGD to gallons per day

895,000 gallons Signup and view all the answers

2.20 MGD to gallons per day

2,200,000 gallons Signup and view all the answers

.019 MGD to gallons per day

19,000 gallons Signup and view all the answers

.999 MGD to gallons per day

999,000 gallons Signup and view all the answers

How much pressure (in psi) does 1 foot of elevation offer?

2.31 psi Signup and view all the answers

Velocity of flow in a water main is expressed in?

Feet per second Signup and view all the answers

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?

600,000 gallons, 13.3% Signup and view all the answers

What is the industry standard for acceptable water loss in a public water supply?

10% or less Signup and view all the answers

If the pH of a water sample is below seven units, it is considered?

Acidic Signup and view all the answers

The average flow from a 5/8 inch x 3/4 inch water meter is _________ gpm?

5-7 Signup and view all the answers

A connection between a possible water supply and a non-potable water supply is?

A cross connection, a possible danger to water customers, and a violation of state regulations. Signup and view all the answers

New water main should be disinfected when?

The pipe is installed and initially filled. Signup and view all the answers

How many pounds of water are in a cubic foot of water?

62.4 pounds Signup and view all the answers

How many pounds of water is in 50,000 gallons of water?

417,000 pounds Signup and view all the answers

How many gallons of water are in a cubic foot of water?

7.48 gallons Signup and view all the answers

What is a water hammer?

The back-and-forth movement of water in a water main when water flows in that main are stopped and started rapidly. Signup and view all the answers

High levels of lead in potable water may cause?

Mental impairment in children and infants. Signup and view all the answers

What is the required range of fluoride in mg/l to be in compliance with Illinois Department of Public Health regulations?

.7 to 1.2 mg/l Signup and view all the answers

Bacti samples show the absence or presence of coliform. If present, the sample contains?

Animal and human feces. Signup and view all the answers

The number of bacti samples collected in a public water supply distribution system is based on?

The population at the supply services. Signup and view all the answers

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.

Monthly Signup and view all the answers

What type of test is commonly used for testing fluoride levels?

SPADNS Test Signup and view all the answers

What type of test is most commonly used for testing chlorine residuals in a small system or in a distribution system?

DPD Test Signup and view all the answers

Sodium thiosulfate is added to a bacti sample bottle to?

Remove any chlorine residual from the sample. Signup and view all the answers

Bacti sample bottle should be?

Filled completely so no errors are present in the bottle after the cap has been replaced. Signup and view all the answers

To collect a bacti sample, the collector must be?

Trained in the proper collection procedures. Signup and view all the answers

When collecting a bacti sample, the lid of the sample bottle should be?

Held bottom down with your fingers on the outside of the rim. Signup and view all the answers

Bacti samples must be analyzed no later than___________ hours after collection.

30 Signup and view all the answers

Testing for THMs can be performed?

By the IEPA lab or certain private certified labs. Signup and view all the answers

A circuit breaker is used to?

Automatically shut down an electrical circuit when overloaded to prevent damage. Signup and view all the answers

What is the minimum combined chlorine residual that is required to be in all parts of a distribution system?

1.0 mg/l Signup and view all the answers

What is free chlorine?

The portion (in mg/l) of chlorine that remains in finished water after the demand for chlorine has been met. Signup and view all the answers

What is total chlorine?

The amount of chlorine remaining after a given contact time. Signup and view all the answers

What is the minimum free chlorine residual that is required to be in all parts of the distribution system?

.5 mg/l Signup and view all the answers

Of these three disinfectants, which is the strongest: Calcium hypochlorite, sodium hypochlorite, or chlorine gas?

Chlorine gas Signup and view all the answers

What is the percentage of available chlorine in chlorine gas?

100% Signup and view all the answers

What is the percentage of available chlorine in calcium hypochlorite?

65 to 70 % Signup and view all the answers

What is the percentage of available chlorine in sodium hypochlorite?

10 to 15% Signup and view all the answers

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?

.7 mg/L Signup and view all the answers

If calcium hypochlorite and oily rags are allowed to come into contact with each other, what will occur?

Ignition and flash fire will occur. Signup and view all the answers

When collecting a bacti sample, the water should be collected after the faucet has run for at least?

A period long enough to adequately flush out the service line to the main. Signup and view all the answers

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?

Neither Signup and view all the answers

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?

$2.92 per thousand gallons. And yes, it is a high cost. Signup and view all the answers

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?

106.5 psi Signup and view all the answers

If a home has a higher pressure than 80 psi, what should they install?

A pressure reducing valve on their service lines. Signup and view all the answers

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?

10 minutes Signup and view all the answers

What is the invert of the pipe?

The lowest point of the exterior of a pipe or conduit. Signup and view all the answers

What is OSHA?

Occupational Safety and Health Administration. Signup and view all the answers

What is a specific capacity as related to groundwater?

Weight of a particle, substance, or chemical solution in relation to the weight of an equal volume of water. Signup and view all the answers

What is static water level?

The elevation or level of the water table when the well pump is not operating. Signup and view all the answers

What is a well casing vent?

It allows air to enter the well during drawdown to prevent vacuum conditions, vents excess air during well recovery. Signup and view all the answers

What is a sounding tube?

Permits the insertion of a water level measuring device, also used to add cleaning agents. Signup and view all the answers

What is a gravel tube?

Permits the operator to see the level of gravel and add gravel as necessary. Signup and view all the answers

What is a pump pedestal?

Supports the weight of the pumping unit. Signup and view all the answers

What is a pump motor base seal?

Provides a watertight seal between the motor base and the concrete support pedestal. Signup and view all the answers

What are sampling taps?

Permits sampling of pumped water. Signup and view all the answers

What is an air-release vacuum breaker valve?

Permits discharge of air in column pipe during startup and admits air during shutdown. Signup and view all the answers

What is a valve pump blowoff?

Used to remove the first water pumped at startup. Signup and view all the answers

What is an air line water level measuring device?

Permits measurement of water level by means of air pressure measurements. Signup and view all the answers

What is the purpose of a check valve?

Acts as an automatic shut-off valve when a pump stops, prevents backflow into the well casing, and helps prevent system pressure from decreasing due to backsiphonage. Signup and view all the answers

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.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

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.