CWEA Wastewater Operator Certification Study Guide – Grade 2 Questions
and Answers | California Water Environment Association (CWEA) |
2026/2027 A+ Exam Preparation Guide
General Wastewater Treatment:
What is the pressure head caused by? - (ANSWER)Water elevation
General Wastewater Treatment:
What color should the piping be that contains reclaimed water? - (ANSWER)purple
General Wastewater Treatment:
What is the term for the height to which a column of water will rise in a well. - (ANSWER)piezometric
surface
General Wastewater Treatment:
In general, what is the maximum practical lift of pumps - (ANSWER)15-25ft
General Wastewater Treatment:
Which one of the following valves is the best to use in throttling a flow situation?
a. gate
b. butterfly
c. globe
d. ball - (ANSWER)globe
General Wastewater Treatment:
,CWEA Wastewater Operator Certification Study Guide – Grade 2 Questions
and Answers | California Water Environment Association (CWEA) |
2026/2027 A+ Exam Preparation Guide
Which one of the following devices is used to measure water depths in storage facilities?
a. transducer
b. Venturi meter
c. magnetic sensor
d. thermistor - (ANSWER)transducer
Wastewater Treatment Facilities:
The velocity in sanitary sewers is approximately: - (ANSWER)2 ft/s
Wastewater Treatment Facilities:
The distance between manholes ranges from - (ANSWER)300-500ft
Wastewater Treatment Facilities:
What should the flow velocity be through a grit channel - (ANSWER)1.0 ft/s
Wastewater Treatment Facilities:
Grit washers are used to______
a. remove some of the organic matter
b. remove large pieces of wood
,CWEA Wastewater Operator Certification Study Guide – Grade 2 Questions
and Answers | California Water Environment Association (CWEA) |
2026/2027 A+ Exam Preparation Guide
c. remove rags and eggshells
d. remove the odors - (ANSWER)remove some of the organic matter
Wastewater Treatment Facilities:
The most common flow-measure device for wastewater is a_____ - (ANSWER)parshall flume
Wastewater Treatment Facilities:
The detention time for primary clarifiers usually has a range of_____hr/s - (ANSWER)1.5-2hr
Wastewater Treatment Facilities:
The effluent from which process is called mixed liquor
a.secondary clarification
b. primary clarification
c. sludge drying bed or pond
d. activated sludge - (ANSWER)activated sludge
Wastewater Treatment Facilities:
Aerobic ponds usually range in depth from ___-____ft - (ANSWER)3-6ft
Wastewater Treatment Facilities:
, CWEA Wastewater Operator Certification Study Guide – Grade 2 Questions
and Answers | California Water Environment Association (CWEA) |
2026/2027 A+ Exam Preparation Guide
Anaerobic ponds usually range in depth from___-___ft - (ANSWER)8-12ft
Wastewater Treatment Facilities:
Another name for a waste stabilization pond is - (ANSWER)raw wastewater lagoon
Wastewater sources & characteristics:
Typically what average percent of total solids in a domestic wastewater, both dissolved and suspended,
are inorganics - (ANSWER)50%
Wastewater sources & characteristics:
Typically, what average percent of total solids in domestic wastewater, both dissolved and suspended,
are inorganics? - (ANSWER)50%
Wastewater sources & characteristics:
Approx. what % of the dissolved solids in wastewater are inorganics - (ANSWER)87%
Wastewater sources & characteristics:
Approximately what % of the dissolved solids in wastewater are organics - (ANSWER)12%
Wastewater sources & characteristics:
and Answers | California Water Environment Association (CWEA) |
2026/2027 A+ Exam Preparation Guide
General Wastewater Treatment:
What is the pressure head caused by? - (ANSWER)Water elevation
General Wastewater Treatment:
What color should the piping be that contains reclaimed water? - (ANSWER)purple
General Wastewater Treatment:
What is the term for the height to which a column of water will rise in a well. - (ANSWER)piezometric
surface
General Wastewater Treatment:
In general, what is the maximum practical lift of pumps - (ANSWER)15-25ft
General Wastewater Treatment:
Which one of the following valves is the best to use in throttling a flow situation?
a. gate
b. butterfly
c. globe
d. ball - (ANSWER)globe
General Wastewater Treatment:
,CWEA Wastewater Operator Certification Study Guide – Grade 2 Questions
and Answers | California Water Environment Association (CWEA) |
2026/2027 A+ Exam Preparation Guide
Which one of the following devices is used to measure water depths in storage facilities?
a. transducer
b. Venturi meter
c. magnetic sensor
d. thermistor - (ANSWER)transducer
Wastewater Treatment Facilities:
The velocity in sanitary sewers is approximately: - (ANSWER)2 ft/s
Wastewater Treatment Facilities:
The distance between manholes ranges from - (ANSWER)300-500ft
Wastewater Treatment Facilities:
What should the flow velocity be through a grit channel - (ANSWER)1.0 ft/s
Wastewater Treatment Facilities:
Grit washers are used to______
a. remove some of the organic matter
b. remove large pieces of wood
,CWEA Wastewater Operator Certification Study Guide – Grade 2 Questions
and Answers | California Water Environment Association (CWEA) |
2026/2027 A+ Exam Preparation Guide
c. remove rags and eggshells
d. remove the odors - (ANSWER)remove some of the organic matter
Wastewater Treatment Facilities:
The most common flow-measure device for wastewater is a_____ - (ANSWER)parshall flume
Wastewater Treatment Facilities:
The detention time for primary clarifiers usually has a range of_____hr/s - (ANSWER)1.5-2hr
Wastewater Treatment Facilities:
The effluent from which process is called mixed liquor
a.secondary clarification
b. primary clarification
c. sludge drying bed or pond
d. activated sludge - (ANSWER)activated sludge
Wastewater Treatment Facilities:
Aerobic ponds usually range in depth from ___-____ft - (ANSWER)3-6ft
Wastewater Treatment Facilities:
, CWEA Wastewater Operator Certification Study Guide – Grade 2 Questions
and Answers | California Water Environment Association (CWEA) |
2026/2027 A+ Exam Preparation Guide
Anaerobic ponds usually range in depth from___-___ft - (ANSWER)8-12ft
Wastewater Treatment Facilities:
Another name for a waste stabilization pond is - (ANSWER)raw wastewater lagoon
Wastewater sources & characteristics:
Typically what average percent of total solids in a domestic wastewater, both dissolved and suspended,
are inorganics - (ANSWER)50%
Wastewater sources & characteristics:
Typically, what average percent of total solids in domestic wastewater, both dissolved and suspended,
are inorganics? - (ANSWER)50%
Wastewater sources & characteristics:
Approx. what % of the dissolved solids in wastewater are inorganics - (ANSWER)87%
Wastewater sources & characteristics:
Approximately what % of the dissolved solids in wastewater are organics - (ANSWER)12%
Wastewater sources & characteristics:
