age 1 of 46
TEXAS WASTEWATER CLASS A FINAL EXAM STUDY
GUIDE 2025/2026 COMPLETE QUESTIONS AND
CORRECT DETAILED ANSWERS WITH RATIONALES ||
100% GUARANTEED PASS <RECENT VERSION>
Seeding of BOD samples is necessary when samples
......ANSWER........(All of the above) have a chlorine residual,
have a previously been chlorinated, have been subjected to high
temperatures, contain high or low pH industrial wastes
Why is recirculation needed in a trickling filter?
......ANSWER........a. Keep the media wet b. Further reduce BOD
c. Flood the filter to control ponding and filter flies
,age 2 of 46
When is blue-green algae the most dominant on a pond
treatment system? ......ANSWER........Summer
A 30-inch diameter wastewater interceptor is observed to be
flowing half-full at about two fps. The approximate volume of
wastewater flowing through the pipe is 3.14x1.25 x 1.25 x 2 =
4.9 cfs x 449 = 2,200 gpm ......ANSWER........c. 2,200 gallons
per minute
A one-cylinder reciprocating sludge pump with a 10-inch bore
and a 5-inch stroke pumps at a rate of 50 cycles per minute.
How many minutes must the pump be operated to pump 5,000
gallons of sludge? 3.14x0.416 x 0.416 x0.416 x 50 x7.48 =
84.5 gpm 5000 gal = 59,2min 84.5 gpm b. 29
......ANSWER........60 minutes
,age 3 of 46
If an existing centrifugal pump motor is replaced with a motor
with 25 percent more speed, the motor horsepower required will
increase by 1.25 x 1.25 x 1.25 = 1.95 ......ANSWER........95
percent
When must TCEQ be notified about expansions of a treatment
facility? ......ANSWER........Before construction
In an anaerobic digester, the percentage of methane and
carbon dioxide gas content should be ......ANSWER........70%
methane, 30% carbon dioxide
The temperature of an anaerobic digester should be maintained
at a minimum of ......ANSWER........95° F
What type of wastewater treatment operates in the endogenous
bacteria growth phase? ......ANSWER........Extended air
, age 4 of 46
Why is recirculation needed in a trickling filter?
......ANSWER........Keep the media wet Further reduce BOD All of
the above (a, b, and c)
What type of fire extinguisher would be used on an electrical
control panel that has been de-energized?
......ANSWER........Class A Class C (a and d)
Disinfection with chlorine is the most effective at a pH of
......ANSWER........6.0
The biomass on a normal functioning RBC has what appearance?
......ANSWER........Grey to brown and 0.05 to 0.1 inch thick
The sludge from a primary clarifier should percent solids?
......ANSWER........4% to 6%
TEXAS WASTEWATER CLASS A FINAL EXAM STUDY
GUIDE 2025/2026 COMPLETE QUESTIONS AND
CORRECT DETAILED ANSWERS WITH RATIONALES ||
100% GUARANTEED PASS <RECENT VERSION>
Seeding of BOD samples is necessary when samples
......ANSWER........(All of the above) have a chlorine residual,
have a previously been chlorinated, have been subjected to high
temperatures, contain high or low pH industrial wastes
Why is recirculation needed in a trickling filter?
......ANSWER........a. Keep the media wet b. Further reduce BOD
c. Flood the filter to control ponding and filter flies
,age 2 of 46
When is blue-green algae the most dominant on a pond
treatment system? ......ANSWER........Summer
A 30-inch diameter wastewater interceptor is observed to be
flowing half-full at about two fps. The approximate volume of
wastewater flowing through the pipe is 3.14x1.25 x 1.25 x 2 =
4.9 cfs x 449 = 2,200 gpm ......ANSWER........c. 2,200 gallons
per minute
A one-cylinder reciprocating sludge pump with a 10-inch bore
and a 5-inch stroke pumps at a rate of 50 cycles per minute.
How many minutes must the pump be operated to pump 5,000
gallons of sludge? 3.14x0.416 x 0.416 x0.416 x 50 x7.48 =
84.5 gpm 5000 gal = 59,2min 84.5 gpm b. 29
......ANSWER........60 minutes
,age 3 of 46
If an existing centrifugal pump motor is replaced with a motor
with 25 percent more speed, the motor horsepower required will
increase by 1.25 x 1.25 x 1.25 = 1.95 ......ANSWER........95
percent
When must TCEQ be notified about expansions of a treatment
facility? ......ANSWER........Before construction
In an anaerobic digester, the percentage of methane and
carbon dioxide gas content should be ......ANSWER........70%
methane, 30% carbon dioxide
The temperature of an anaerobic digester should be maintained
at a minimum of ......ANSWER........95° F
What type of wastewater treatment operates in the endogenous
bacteria growth phase? ......ANSWER........Extended air
, age 4 of 46
Why is recirculation needed in a trickling filter?
......ANSWER........Keep the media wet Further reduce BOD All of
the above (a, b, and c)
What type of fire extinguisher would be used on an electrical
control panel that has been de-energized?
......ANSWER........Class A Class C (a and d)
Disinfection with chlorine is the most effective at a pH of
......ANSWER........6.0
The biomass on a normal functioning RBC has what appearance?
......ANSWER........Grey to brown and 0.05 to 0.1 inch thick
The sludge from a primary clarifier should percent solids?
......ANSWER........4% to 6%
