Texas Wastewater Class A Exam 2026
Complete Study Guide and 100% Verified
Answers
‣ 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
‣ 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
‣ 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%
‣ What is eutrophication in a pond system? Answer: Enrichment with
nitrogen and phosphorous Causes algae blooms (b and c)
, ‣ How often should pH meters be calibrated? Answer: Daily
‣ In Texas, pH meters are required to be calibrated on how many
buffers? Answer: two
‣ An industrial complex has a BOD discharge to the POTW of 500
pounds per day. The population equivalent of this industry is 500 lbs =
2,941 0.17 lbs BOD person Answer: 2941
‣ The parameters of the BOD test are Answer: 5 days at 20° Centigrade
‣ Standard Dimension Ratio in pvc pipe is defined as Answer: Ratio of
OD pipe diameter to wall thickness
‣ How should shoring be removed from a trench? Answer: up from the
bottom up
‣ In low pressure sewer systems where each tap must have a grinder
pump lift station, station is considered to be Answer: part of the
collection system and the responsibility of the utility
‣ Effective communication depends on Answer: being a good listener
Complete Study Guide and 100% Verified
Answers
‣ 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
‣ 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
‣ 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%
‣ What is eutrophication in a pond system? Answer: Enrichment with
nitrogen and phosphorous Causes algae blooms (b and c)
, ‣ How often should pH meters be calibrated? Answer: Daily
‣ In Texas, pH meters are required to be calibrated on how many
buffers? Answer: two
‣ An industrial complex has a BOD discharge to the POTW of 500
pounds per day. The population equivalent of this industry is 500 lbs =
2,941 0.17 lbs BOD person Answer: 2941
‣ The parameters of the BOD test are Answer: 5 days at 20° Centigrade
‣ Standard Dimension Ratio in pvc pipe is defined as Answer: Ratio of
OD pipe diameter to wall thickness
‣ How should shoring be removed from a trench? Answer: up from the
bottom up
‣ In low pressure sewer systems where each tap must have a grinder
pump lift station, station is considered to be Answer: part of the
collection system and the responsibility of the utility
‣ Effective communication depends on Answer: being a good listener
