CWEA COLLECTIONS FINAL EXAM QUESTIONS WITH
ANSWERS GRADED A+ 2025/2026
Category 1 SSO's that discharge to a drainage channel and/or surface water must be
reported within: - 2 hours
To report in the Statewide SSO Data-base California Integrated Water Quality System
(CIWQS), regarding the location of a Category 2 SSO, you must know: - the GPS
coordinates
Biological activity in long, sluggish-flow, flat grade sewer lines will likely cause odors,
true or false? - True
Flatter sewer line grades may cause added sewer maintenance expense and odor
nuisance. The problem is most likely caused by: - A decrease in velocity allowing
organic and inorganic solids to settle out
Infiltration from a high water table can be one source of excessive clear water in a
collection system, true or false? - True
What is the first thing to consider when selecting a solution to clear a stoppage in a
sewer? - Cause of stoppage
The interior of 300 feet of 12-inch pipe is uniformly coated with one inch of grease. How
many gallons will this pipe hold when filled with water? - 12 inches (diameter of pipe) - 2
inches (grease on pipe) = 10 inches
Convert inches to feet:
10 inches x (1 foot / 12 inches) = 0.833 feet
Volume of a right regular cylinder:
V = 0.785 x Diameter x Diameter x Length of Pipe
V = 0.785 x 0.833 ft x 0.833 ft x 300 ft
V = 163.41 cubic feet
Convert to Gallons:
163.41 cu ft x (7.48 gal / 1 cu ft) = 1223.31 gal
Infiltration can be caused by cracked pipes, true or false? - True
The main reason for adding sodium hypochlorite to sewers is to control: - Odor
Roots can enter collection systems through pipe cracks, true or false? - True
The lowest point on the inside of a pipeline is called the: - Invert
How often must an excavation site and adjacent areas be inspected for hazardous
conditions? - Daily
, Working in an un-sloped trench with no shoring is one option of Protective Shoring
Systems, true or false? - False. Some options are proper stopping or benching of the
sides of the excavation, supporting the sides of a trench with shoring, and using a shield
in the excavation area.
Proper operation and maintenance of wastewater collection is keeping wastewater
flowing through pipes, true or false? - True
Minimum design velocity for a sewer should greater than: - 2 feet per second
Vitrified Clay pipe is a Rigid type of pipe, true or false? - True
Barrels, lids, cones, and backflow devices are all included in Manholes, true or false? -
False. All are included except for backflow devices.
Sewer testing methods include air, water, mandrill, and sewage, true or false? - False.
Sewer testing methods do not include sewage.
Using high velocity cleaners is one method included in hydraulic sewer cleaning, true or
false? - True
A flow of 650 gpm would be how many MGD? - 650 gpm x (1440 min / 1 day) = 936000
gpd
936000 x (1 MG / 1000000 gal) = 0.936 MGD
One of the advantages of using CCTV is that the length and severity of defective pipe
areas can be recorded, true or false? - True
Offset joints are one hazard that may damage a TV camera going through a sewer, true
or false? - True
What is the total volume of 1000 feet of 8 inch line? - Convert inches to feet:
8 inches x (1 foot / 12 inches) = 0.666
Volume of a right regular cylinder:
V = 0.785 x Diameter x Diameter x Length of Pipe
V = 0.785 x 0.666 ft x 0.666 ft x 1000 ft
V = 348.19 cu ft
Convert to gallons:
348.19 cu ft x (7.48 gal / 1 cu ft) = 2604.47 gal
If an 8 inch force main has a metered flow rate of 400000 gpd, what is the velocity? -
Velocity = Flow / Area
Area = 0.785 x Diameter x Diameter
When finding Area, convert Diameter into feet
8 in x (1 ft / 12 in) = 0.667 ft
Area = 0.785 x 0.667 ft x 0.667 ft = 0.349 sq ft
ANSWERS GRADED A+ 2025/2026
Category 1 SSO's that discharge to a drainage channel and/or surface water must be
reported within: - 2 hours
To report in the Statewide SSO Data-base California Integrated Water Quality System
(CIWQS), regarding the location of a Category 2 SSO, you must know: - the GPS
coordinates
Biological activity in long, sluggish-flow, flat grade sewer lines will likely cause odors,
true or false? - True
Flatter sewer line grades may cause added sewer maintenance expense and odor
nuisance. The problem is most likely caused by: - A decrease in velocity allowing
organic and inorganic solids to settle out
Infiltration from a high water table can be one source of excessive clear water in a
collection system, true or false? - True
What is the first thing to consider when selecting a solution to clear a stoppage in a
sewer? - Cause of stoppage
The interior of 300 feet of 12-inch pipe is uniformly coated with one inch of grease. How
many gallons will this pipe hold when filled with water? - 12 inches (diameter of pipe) - 2
inches (grease on pipe) = 10 inches
Convert inches to feet:
10 inches x (1 foot / 12 inches) = 0.833 feet
Volume of a right regular cylinder:
V = 0.785 x Diameter x Diameter x Length of Pipe
V = 0.785 x 0.833 ft x 0.833 ft x 300 ft
V = 163.41 cubic feet
Convert to Gallons:
163.41 cu ft x (7.48 gal / 1 cu ft) = 1223.31 gal
Infiltration can be caused by cracked pipes, true or false? - True
The main reason for adding sodium hypochlorite to sewers is to control: - Odor
Roots can enter collection systems through pipe cracks, true or false? - True
The lowest point on the inside of a pipeline is called the: - Invert
How often must an excavation site and adjacent areas be inspected for hazardous
conditions? - Daily
, Working in an un-sloped trench with no shoring is one option of Protective Shoring
Systems, true or false? - False. Some options are proper stopping or benching of the
sides of the excavation, supporting the sides of a trench with shoring, and using a shield
in the excavation area.
Proper operation and maintenance of wastewater collection is keeping wastewater
flowing through pipes, true or false? - True
Minimum design velocity for a sewer should greater than: - 2 feet per second
Vitrified Clay pipe is a Rigid type of pipe, true or false? - True
Barrels, lids, cones, and backflow devices are all included in Manholes, true or false? -
False. All are included except for backflow devices.
Sewer testing methods include air, water, mandrill, and sewage, true or false? - False.
Sewer testing methods do not include sewage.
Using high velocity cleaners is one method included in hydraulic sewer cleaning, true or
false? - True
A flow of 650 gpm would be how many MGD? - 650 gpm x (1440 min / 1 day) = 936000
gpd
936000 x (1 MG / 1000000 gal) = 0.936 MGD
One of the advantages of using CCTV is that the length and severity of defective pipe
areas can be recorded, true or false? - True
Offset joints are one hazard that may damage a TV camera going through a sewer, true
or false? - True
What is the total volume of 1000 feet of 8 inch line? - Convert inches to feet:
8 inches x (1 foot / 12 inches) = 0.666
Volume of a right regular cylinder:
V = 0.785 x Diameter x Diameter x Length of Pipe
V = 0.785 x 0.666 ft x 0.666 ft x 1000 ft
V = 348.19 cu ft
Convert to gallons:
348.19 cu ft x (7.48 gal / 1 cu ft) = 2604.47 gal
If an 8 inch force main has a metered flow rate of 400000 gpd, what is the velocity? -
Velocity = Flow / Area
Area = 0.785 x Diameter x Diameter
When finding Area, convert Diameter into feet
8 in x (1 ft / 12 in) = 0.667 ft
Area = 0.785 x 0.667 ft x 0.667 ft = 0.349 sq ft
