FREE WW Collection Systems Questions and Answers

Question 1

What is the generally accepted minimum self-cleansing velocity in a sanitary sewer to prevent the deposition of solids?

Accepted Answer

2.0 fps

Answer

0.5 fps

Answer

1.0 fps

Answer

5.0 fps

Question 2

Which piece of equipment is most effective for removing heavy grease blockages from a sewer line?

Accepted Answer

High-Pressure Water Jetter

Answer

Mechanical Rodder

Answer

Sewer Bucket Machine

Answer

Hand Rods

Question 3

In a wastewater lift station, what is the primary function of a check valve?

Accepted Answer

To prevent backflow into the wet well

Answer

To regulate the speed of the pump

Answer

To release air from the force main

Answer

To measure the flow rate from the pump

Question 4

The characteristic 'rotten egg' smell in a collection system is caused by the presence of which gas?

Accepted Answer

Hydrogen Sulfide (H₂S)

Answer

Methane (CH₄)

Answer

Ammonia (NH₃)

Answer

Carbon Dioxide (CO₂)

Question 5

What is the most critical first step that must be taken before an employee enters a manhole?

Accepted Answer

Test the atmosphere with a calibrated gas meter

Answer

Set up traffic cones around the area

Answer

Notify the upstream industrial users

Answer

Check the manhole lid for structural integrity

Question 6

Unwanted groundwater entering the sewer system through cracks, faulty joints, or porous pipe walls is known as:

Accepted Answer

Infiltration

Answer

Inflow

Answer

Exfiltration

Answer

Surcharge

Question 7

Which type of sewer pipe material is a ceramic product known for its high resistance to chemical and acid corrosion, particularly from hydrogen sulfide?

Accepted Answer

Vitrified Clay Pipe (VCP)

Answer

Polyvinyl Chloride (PVC)

Answer

Ductile Iron Pipe (DIP)

Answer

Reinforced Concrete Pipe (RCP)