1|Page
Texas Wastewater Class A
2026|Comprehensive Q&A For
Certification Success
Seeding of BOD samples is necessary when samples - correct-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
When is blue-green algae the most dominant on a pond treatment system? -
correct-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 - correct-answer - c. 2,200
gallons per minute
,2|Page
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 - correct-answer - 60 minutes
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 - correct-answer - 95 percent
When must TCEQ be notified about expansions of a treatment facility? - correct-
answer - Before construction
In an anaerobic digester, the percentage of methane and carbon dioxide gas
content should be - correct-answer - 70% methane, 30% carbon dioxide
,3|Page
The temperature of an anaerobic digester should be maintained at a minimum of
- correct-answer - 95° F
What type of wastewater treatment operates in the endogenous bacteria growth
phase? - correct-answer - Extended air
Why is recirculation needed in a trickling filter? - correct-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? - correct-answer - Class A Class C (a and d)
Disinfection with chlorine is the most effective at a pH of - correct-answer - 6.0
, 4|Page
The biomass on a normal functioning RBC has what appearance? - correct-answer
- Grey to brown and 0.05 to 0.1 inch thick
The sludge from a primary clarifier should percent solids? - correct-answer - 4% to
6%
What is eutrophication in a pond system? - correct-answer - Enrichment with
nitrogen and phosphorous Causes algae blooms (b and c)
How often should pH meters be calibrated? - correct-answer - Daily
In Texas, pH meters are required to be calibrated on how many buffers? - correct-
answer - two
Texas Wastewater Class A
2026|Comprehensive Q&A For
Certification Success
Seeding of BOD samples is necessary when samples - correct-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
When is blue-green algae the most dominant on a pond treatment system? -
correct-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 - correct-answer - c. 2,200
gallons per minute
,2|Page
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 - correct-answer - 60 minutes
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 - correct-answer - 95 percent
When must TCEQ be notified about expansions of a treatment facility? - correct-
answer - Before construction
In an anaerobic digester, the percentage of methane and carbon dioxide gas
content should be - correct-answer - 70% methane, 30% carbon dioxide
,3|Page
The temperature of an anaerobic digester should be maintained at a minimum of
- correct-answer - 95° F
What type of wastewater treatment operates in the endogenous bacteria growth
phase? - correct-answer - Extended air
Why is recirculation needed in a trickling filter? - correct-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? - correct-answer - Class A Class C (a and d)
Disinfection with chlorine is the most effective at a pH of - correct-answer - 6.0
, 4|Page
The biomass on a normal functioning RBC has what appearance? - correct-answer
- Grey to brown and 0.05 to 0.1 inch thick
The sludge from a primary clarifier should percent solids? - correct-answer - 4% to
6%
What is eutrophication in a pond system? - correct-answer - Enrichment with
nitrogen and phosphorous Causes algae blooms (b and c)
How often should pH meters be calibrated? - correct-answer - Daily
In Texas, pH meters are required to be calibrated on how many buffers? - correct-
answer - two
