Wastewater Class 2 (CWEA) Multiple Choice Questions with Verified
Solutions 2026/2027 | A+ Grade | Certification Study Guide|CWEA
Wastewater Collections Grade 2 – Verified Exam Prep
The threahold limit value concentration for chlorine vapour is:
a. 0.1 ppm
b. 0.3 ppm
c. 0.5 ppm
d. 1.0 ppm - (ANSWER)c. 0.5ppm
When working in confined spaces where flammable gasesmay be present, use only tools made of:
a. stainless steel
b. lead
c. iron
d. a non-sparking alloy - (ANSWER)d. a non-sparking alloy
In addition to the worker entering a confined space, what is thw minimum number of people required to
be present during a confined space entry?
a. 1
b. 2
c. 3
d. 4 - (ANSWER)a. 1
Hearing protection must be made available to all employees exposed to noise levels above:
a. 85 db averaged over 8 working hours
b. 850 db averaged over 8 working hours
c. 85 db continuously for 8 working hours
d. 85 db at any point in the 8 hour workday - (ANSWER)a. 85 db averaged over 8 working hours
Recommended hygiene practices to minimize the risk if being infected by wastewater pathogens include:
, Wastewater Class 2 (CWEA) Multiple Choice Questions with Verified
Solutions 2026/2027 | A+ Grade | Certification Study Guide|CWEA
Wastewater Collections Grade 2 – Verified Exam Prep
a. only rubbing your eyes while working if you are wearing impervious gloves
b. washing your hands before the beginning of your shift
c. changing out your work clothes and showering before leaving work
d. reading the material safety data sheets for all chemicals used in the plant - (ANSWER)c. changing out
your work clothes and showering before leaving work
the BOD loading rate divided by the quantity of microorganisms present in the biological reactor
(aeration tanks) is known as:
a. organic loading
b. toxicity
c. hydraulic loading
d. food to microorganism ratio - (ANSWER)d. food to microorganism ratio
The food to microorganism ratio is the ratio of the mass of organic loading to the mass of
microorganisms in the biological reactors
white fluffy foam on the biological reactors in an activated sludge process is usually caused by:
a. insufficient biomass to treat the incoming waste
B. Low b o d
C. high do
D. Too little sludge being waste from process - (ANSWER)a. insufficient biomass to treat the incoming
waste
Stiff white foam typically indicates that there are too few microorganisms in the system to treat the
incoming waste. This shortage can be caused by start-up conditions, excessive wasting, toxic materials in
the influent, low do or other conditions harmful to the microorganism population.
typical components of grit removal systems include:
Solutions 2026/2027 | A+ Grade | Certification Study Guide|CWEA
Wastewater Collections Grade 2 – Verified Exam Prep
The threahold limit value concentration for chlorine vapour is:
a. 0.1 ppm
b. 0.3 ppm
c. 0.5 ppm
d. 1.0 ppm - (ANSWER)c. 0.5ppm
When working in confined spaces where flammable gasesmay be present, use only tools made of:
a. stainless steel
b. lead
c. iron
d. a non-sparking alloy - (ANSWER)d. a non-sparking alloy
In addition to the worker entering a confined space, what is thw minimum number of people required to
be present during a confined space entry?
a. 1
b. 2
c. 3
d. 4 - (ANSWER)a. 1
Hearing protection must be made available to all employees exposed to noise levels above:
a. 85 db averaged over 8 working hours
b. 850 db averaged over 8 working hours
c. 85 db continuously for 8 working hours
d. 85 db at any point in the 8 hour workday - (ANSWER)a. 85 db averaged over 8 working hours
Recommended hygiene practices to minimize the risk if being infected by wastewater pathogens include:
, Wastewater Class 2 (CWEA) Multiple Choice Questions with Verified
Solutions 2026/2027 | A+ Grade | Certification Study Guide|CWEA
Wastewater Collections Grade 2 – Verified Exam Prep
a. only rubbing your eyes while working if you are wearing impervious gloves
b. washing your hands before the beginning of your shift
c. changing out your work clothes and showering before leaving work
d. reading the material safety data sheets for all chemicals used in the plant - (ANSWER)c. changing out
your work clothes and showering before leaving work
the BOD loading rate divided by the quantity of microorganisms present in the biological reactor
(aeration tanks) is known as:
a. organic loading
b. toxicity
c. hydraulic loading
d. food to microorganism ratio - (ANSWER)d. food to microorganism ratio
The food to microorganism ratio is the ratio of the mass of organic loading to the mass of
microorganisms in the biological reactors
white fluffy foam on the biological reactors in an activated sludge process is usually caused by:
a. insufficient biomass to treat the incoming waste
B. Low b o d
C. high do
D. Too little sludge being waste from process - (ANSWER)a. insufficient biomass to treat the incoming
waste
Stiff white foam typically indicates that there are too few microorganisms in the system to treat the
incoming waste. This shortage can be caused by start-up conditions, excessive wasting, toxic materials in
the influent, low do or other conditions harmful to the microorganism population.
typical components of grit removal systems include:
