Wastewater Collections ACTUAL EXAM ALL
QUESTIONS AND ANSWERS ALREADY
GRADED A+. 100% VERIFIED SOLUTIONS |
UPDATED PER LATEST GUIDELINES |
GRADED A+
Domain: Collection System Maintenance & Operation
Question 1
What is the purpose of a check valve in a wastewater collection system?
A) Stop flow in both directions
B) Regulate velocity
C) Permit flow in only one direction
D) Permit air to escape from the pipe
Answer: C) Permit flow in only one direction
Rationale: Check valves are designed to permit flow in only one direction, preventing backflow.
They are commonly used on discharge lines from lift stations to prevent wastewater from
flowing back into the wet well when the pump is off. They are essential for preventing flooding
and maintaining system integrity .
Question 2
Maintenance records are most important for which purpose?
A) Showing employees emergency plans
B) Protecting the agency against liability
C) Department used for personal suspension
D) Justifying salary increase
Answer: B) Protecting the agency against liability
,Rationale: Accurate and thorough maintenance records provide a legal and regulatory history of
system upkeep. They demonstrate that the agency followed proper procedures, which is vital
for defending against claims of negligence or regulatory non-compliance .
Question 3
The purpose of an electrical lockout/tagout device is to:
A) Positively prevent the operation of an electrical circuit
B) Lock out an electrical switch box door
C) Keep operators out of an electrical control room
D) Introduce electric current to a specific circuit
Answer: A) Positively prevent the operation of an electrical circuit
Rationale: Lockout/tagout (LOTO) devices are used to isolate energy sources, positively
preventing the accidental operation of machinery or electrical circuits during maintenance. This
is a critical safety procedure to protect workers from hazardous energy .
Question 4
What is the primary reason infiltration and inflow (I/I) should be reduced in a collection system?
A) Reduce dilution of the wastewater reaching the plant
B) Reduce the hydraulic load at the treatment plant
C) Decrease the strength of the wastewater
D) Increase the volume of wastewater for treatment
Answer: B) Reduce the hydraulic load at the treatment plant
Rationale: Inflow and infiltration introduce excess clean water into the sewer system, increasing
the hydraulic load on the treatment plant. This can lead to bypasses, overflows, and increased
treatment costs. Reducing I/I protects the environment and improves plant efficiency .
Question 5
The proper maintenance of a wastewater collection system can often eliminate odor and
corrosion problems by controlling the release of:
A) Hydrogen peroxide
B) Chlorine dioxide
, C) Sulfur dioxide
D) Hydrogen sulfide
Answer: D) Hydrogen sulfide
Rationale: Hydrogen sulfide (H₂S) is a colorless gas with a rotten egg smell that is generated in
anaerobic conditions. It is a primary cause of odor complaints and can lead to significant
corrosion of concrete and metal pipes if not controlled .
Question 6
The best place to look for information on maintaining a new piece of equipment is in:
A) Original equipment manufacturer manuals
B) Past history of other equipment
C) Trade manuals
D) Similar manufacturers manuals
Answer: A) Original equipment manufacturer manuals
Rationale: The manufacturer's manual is the definitive source for proper maintenance
procedures, specific to that model. It contains safety guidelines, maintenance schedules, and
troubleshooting guides. Relying on other sources for a new piece of equipment could lead to
errors, void warranties, and create safety hazards .
Question 7
Closing a valve on a hydrant too quickly causes:
A) No problems in distribution piping
B) Dosage calculation problems
C) Water hammer in the line
D) Pipe fittings to become more secure
Answer: C) Water hammer in the line
Rationale: When a valve is closed too quickly, the moving water in the pipe is suddenly stopped,
creating a pressure surge known as water hammer. This can cause significant damage to pipes,
fittings, and equipment .
QUESTIONS AND ANSWERS ALREADY
GRADED A+. 100% VERIFIED SOLUTIONS |
UPDATED PER LATEST GUIDELINES |
GRADED A+
Domain: Collection System Maintenance & Operation
Question 1
What is the purpose of a check valve in a wastewater collection system?
A) Stop flow in both directions
B) Regulate velocity
C) Permit flow in only one direction
D) Permit air to escape from the pipe
Answer: C) Permit flow in only one direction
Rationale: Check valves are designed to permit flow in only one direction, preventing backflow.
They are commonly used on discharge lines from lift stations to prevent wastewater from
flowing back into the wet well when the pump is off. They are essential for preventing flooding
and maintaining system integrity .
Question 2
Maintenance records are most important for which purpose?
A) Showing employees emergency plans
B) Protecting the agency against liability
C) Department used for personal suspension
D) Justifying salary increase
Answer: B) Protecting the agency against liability
,Rationale: Accurate and thorough maintenance records provide a legal and regulatory history of
system upkeep. They demonstrate that the agency followed proper procedures, which is vital
for defending against claims of negligence or regulatory non-compliance .
Question 3
The purpose of an electrical lockout/tagout device is to:
A) Positively prevent the operation of an electrical circuit
B) Lock out an electrical switch box door
C) Keep operators out of an electrical control room
D) Introduce electric current to a specific circuit
Answer: A) Positively prevent the operation of an electrical circuit
Rationale: Lockout/tagout (LOTO) devices are used to isolate energy sources, positively
preventing the accidental operation of machinery or electrical circuits during maintenance. This
is a critical safety procedure to protect workers from hazardous energy .
Question 4
What is the primary reason infiltration and inflow (I/I) should be reduced in a collection system?
A) Reduce dilution of the wastewater reaching the plant
B) Reduce the hydraulic load at the treatment plant
C) Decrease the strength of the wastewater
D) Increase the volume of wastewater for treatment
Answer: B) Reduce the hydraulic load at the treatment plant
Rationale: Inflow and infiltration introduce excess clean water into the sewer system, increasing
the hydraulic load on the treatment plant. This can lead to bypasses, overflows, and increased
treatment costs. Reducing I/I protects the environment and improves plant efficiency .
Question 5
The proper maintenance of a wastewater collection system can often eliminate odor and
corrosion problems by controlling the release of:
A) Hydrogen peroxide
B) Chlorine dioxide
, C) Sulfur dioxide
D) Hydrogen sulfide
Answer: D) Hydrogen sulfide
Rationale: Hydrogen sulfide (H₂S) is a colorless gas with a rotten egg smell that is generated in
anaerobic conditions. It is a primary cause of odor complaints and can lead to significant
corrosion of concrete and metal pipes if not controlled .
Question 6
The best place to look for information on maintaining a new piece of equipment is in:
A) Original equipment manufacturer manuals
B) Past history of other equipment
C) Trade manuals
D) Similar manufacturers manuals
Answer: A) Original equipment manufacturer manuals
Rationale: The manufacturer's manual is the definitive source for proper maintenance
procedures, specific to that model. It contains safety guidelines, maintenance schedules, and
troubleshooting guides. Relying on other sources for a new piece of equipment could lead to
errors, void warranties, and create safety hazards .
Question 7
Closing a valve on a hydrant too quickly causes:
A) No problems in distribution piping
B) Dosage calculation problems
C) Water hammer in the line
D) Pipe fittings to become more secure
Answer: C) Water hammer in the line
Rationale: When a valve is closed too quickly, the moving water in the pipe is suddenly stopped,
creating a pressure surge known as water hammer. This can cause significant damage to pipes,
fittings, and equipment .
