Question 1

What is the purpose of an air gap?

Accepted Answer

A) Reduces corrosion within the distribution system 
B) Eliminates the need for lift station check valves 
C) Prevents contamination of a potable water supply 
D) Both A and C 
A) Reduces corrosion within the distribution system 
B) Eliminates the need for lift station check valves 
C) Prevents contamination of a potable water supply 
D) Both A and C C

Question 2

Concerning atmospheric vacuum breakers (ABV), which of the following statements is incorrect?

Accepted Answer

A) The AVB is always located downstream from all shut-off valves 
B) The AVB air inlet valve is open when water flows in the normal direction 
C) AVB valves do not operate properly when under continuous pressure for more than 12 hours in a 24-hour period 
D) None of the above 
A) The AVB is always located downstream from all shut-off valves 
B) The AVB air inlet valve is open when water flows in the normal direction 
C) AVB valves do not operate properly when under continuous pressure for more than 12 hours in a 24-hour period 
D) None of the above B

Question 3

How much water (in approximate million gallons per day (MGD)) can be treated in a detention basin with the dimensions 15 feet by 10 feet by 8 feet deep and a required detention time of 60 minutes?

Accepted Answer

A) 0.22 MGD 
B) 12.93 MGD 
C) 149.6 MGD 
D) None of the above 
A) 0.22 MGD 
B) 12.93 MGD 
C) 149.6 MGD 
D) None of the above A

Question 4

What is the required chlorinator setting (in pounds per day (lbs/day Cl2)) to treat a flow of 1.78 million gallons per day (MGD) with a chlorine dose of 4 milligrams/liter (mg/L)?

Accepted Answer

A) 7.12 lbs/day Cl2 
B) 14.8 lbs/day Cl2 
C) 59.4 lbs/day Cl2 
D) Not enough information provided 
A) 7.12 lbs/day Cl2 
B) 14.8 lbs/day Cl2 
C) 59.4 lbs/day Cl2 
D) Not enough information provided

Question 5

What is the average filtration rate (in GPM/sq. ft.) for a plant with three 10-foot square filters that treats 1 million gallons in 24 hours of continuous operation?

Accepted Answer

A) 0.33 GPM/sq. ft. 
B) 2.32 GPM/sq. ft. 
C) 6.95 GPM/sq. ft. 
D) Not enough information provided 
A) 0.33 GPM/sq. ft. 
B) 2.32 GPM/sq. ft. 
C) 6.95 GPM/sq. ft. 
D) Not enough information provided

Question 6

Which criteria are used to determine the width of the top of an excavated trench when installing waterlines?

Accepted Answer

A) Depth and diameter of pipe 
B) Local soil type and groundwater elevation 
C) Depth of frost line 
D) All of the above 
A) Depth and diameter of pipe 
B) Local soil type and groundwater elevation 
C) Depth of frost line 
D) All of the above

Question 7

Which of the following is not recommended when testing polyvinyl chloride (PVC) pressure pipe?

Accepted Answer

A) Locate testing connection at the lowest point of the line 
B) Properly backfill pipe trench 
C) Use air pressure for testing 
D) Use hydrostatic pressure for testing 
A) Locate testing connection at the lowest point of the line 
B) Properly backfill pipe trench 
C) Use air pressure for testing 
D) Use hydrostatic pressure for testing

Question 8

What is the approximate capacity (in gallons) of a 12-foot diameter circular lime softening tank that has a 10 foot water depth?

Accepted Answer

A) 898 gallons 
B) 8,460 gallons 
C) 10,770 gallons 
D) Not enough information provided 
A) 898 gallons 
B) 8,460 gallons 
C) 10,770 gallons 
D) Not enough information provided

Question 9

What is the purpose of a thrust block when designing water distribution systems?

Accepted Answer

A) Prevents pipe movement when a pressure system is activated and pressurized 
B) Prevents backsiphonage and contamination 
C) Used to isolate pressure pipe sections 
D) None of the above 
A) Prevents pipe movement when a pressure system is activated and pressurized 
B) Prevents backsiphonage and contamination 
C) Used to isolate pressure pipe sections 
D) None of the above

Question 10

Flocculation occurs during which of the following water treatment processes?

Accepted Answer

A) Coagulation 
B) Sedimentation 
C) Filtration 
D) Disinfection 
A) Coagulation 
B) Sedimentation 
C) Filtration 
D) Disinfection

What is the purpose of an air gap?

Concerning atmospheric vacuum breakers (ABV), which of the following statements is incorrect?

How much water (in approximate million gallons per day (MGD)) can be treated in a detention basin with the dimensions 15 feet by 10 feet by 8 feet deep and a required detention time of 60 minutes?

What is the required chlorinator setting (in pounds per day (lbs/day Cl₂)) to treat a flow of 1.78 million gallons per day (MGD) with a chlorine dose of 4 milligrams/liter (mg/L)?

What is the average filtration rate (in GPM/sq. ft.) for a plant with three 10-foot square filters that treats 1 million gallons in 24 hours of continuous operation?

Which criteria are used to determine the width of the top of an excavated trench when installing waterlines?

Which of the following is not recommended when testing polyvinyl chloride (PVC) pressure pipe?

What is the approximate capacity (in gallons) of a 12-foot diameter circular lime softening tank that has a 10 foot water depth?

What is the purpose of a thrust block when designing water distribution systems?

Flocculation occurs during which of the following water treatment processes?

Earth Retention

Earth Structures

Earthworks

Estimation

Foundations

Hydraulics Closed

Hydraulics Open

Hydrology

Material Mechanics

Material QC

Member Design

Scheduling

Soil and Materials

Soil Mechanics

Struct Loading

Struct Materials

Struct Analysis

Subsurface

Transportation

Waste Water

Filters

Exam 21: Water Treatment

What is the purpose of an air gap?

Concerning atmospheric vacuum breakers (ABV), which of the following statements is incorrect?

How much water (in approximate million gallons per day (MGD)) can be treated in a detention basin with the dimensions 15 feet by 10 feet by 8 feet deep and a required detention time of 60 minutes?

What is the required chlorinator setting (in pounds per day (lbs/day Cl2)) to treat a flow of 1.78 million gallons per day (MGD) with a chlorine dose of 4 milligrams/liter (mg/L)?

What is the average filtration rate (in GPM/sq. ft.) for a plant with three 10-foot square filters that treats 1 million gallons in 24 hours of continuous operation?

Which criteria are used to determine the width of the top of an excavated trench when installing waterlines?

Which of the following is not recommended when testing polyvinyl chloride (PVC) pressure pipe?

What is the approximate capacity (in gallons) of a 12-foot diameter circular lime softening tank that has a 10 foot water depth?

What is the purpose of a thrust block when designing water distribution systems?

Flocculation occurs during which of the following water treatment processes?

Earth Retention

Earth Structures

Earthworks

Estimation

Foundations

Hydraulics Closed

Hydraulics Open

Hydrology

Material Mechanics

Material QC

Member Design

Scheduling

Soil and Materials

Soil Mechanics

Struct Loading

Struct Materials

Struct Analysis

Subsurface

Transportation

Waste Water

Filters

What is the required chlorinator setting (in pounds per day (lbs/day Cl₂)) to treat a flow of 1.78 million gallons per day (MGD) with a chlorine dose of 4 milligrams/liter (mg/L)?