TEXAS WASTEWATER CLASS A
CERTIFICATION EVALUATION TEST 2026 FULL
QUESTIONS AND CORRECT ANSWERS
ALREADY PASSED GRADED A+
◉ Which of activated sludge has two aeration basins per single
treatment unit? Answer: Contact stabilization
◉ 27. A complete mix activated sludge plant has a fast settling
sludge and high amounts of pin floc leaving the clarifier. One method
of correcting the problem is to Answer: Increase F/M ratio by
wasting more
◉ problem is Testing of mixed liquor indicates the MLSS is 2500
mg/L and the settling test shows that a 1000 ml sample settles to
400 mls after 30 minutes. What is the SVI? 400 x 1000 2500 160
Answer: 160
◉ In the problem above, what the sludge quality? Answer: Bulking
◉ Which activated sludge process has 18 to 20 + hours detention
time in the aeration basin? Answer: Extended air
,◉ What is the minimum clearance from the sidewall of a pipe to the
trench wall in an excavation? Answer: 4 inches
◉ What is the definition of pH? Answer: The logarithm of the
reciprocal of the hydrogen ion concentration The negative logarithm
of the hydrogen ion concentration
◉ How often should pH meters be calibrated? Answer: Daily
◉ trench is 4,100 feet long, four 4 wide and 6 feet deep. There is a
12-inch diameter pipe in the bottom of the trench. How many cubic
yards of material were removed from the trench? 4x6x4,100 3,644
27 Answer: 3,644
◉ In the problem above, how many cubic yards of material will be
required to fill the trench? 3.14x0.5 x0.5 x 4,100 =119cu yds 27
3,644 -119 = 3,525 Answer: 3,525
◉ What is the standard chlorine residual and contact time on Texas
discharge permits? Answer: e. None of the above organization
increases,
◉ As the complexity of an organization increases, what management
function becomes most important? Answer: Planning
, ◉ The following scenario is to be used in answering questions 38,
39, and 40. A pump with a 15-inch impeller is running at 1170 RPM
s, with pump efficiency of 75%, and is pumping 500 gpm with 75
feet of head. If the RPM of the pump is increased to 1750 RPMS
calculate the following: New output in gpm: Answer: 1750 1770 =F =
1.5 500 x 1.5 = 750 gpm 750
◉ New head in feet: 75 x 1.5 x 1.5 = 168.75 Answer: 170
◉ New horsepower required: Answer: 750 x 170 - 43 3960 x 0.75 a.
43
◉ What compound or compounds are formed when Cl, combines
with water? Answer: Both a and d
◉ When chlorinating treated wastewater, what chlorine residual do
we test for? Answer: Chloramine and Total
◉ What is the standard pH range on Texas effluent discharge
permits? Answer: b. 6.0 to 9.0
◉ A wastewater treatment plant has a clarifier that is 80 feet in
diameter and is 12 feet deep. The flow is 2.5 mgd. The single weir is
two feet inside the outer wall and is 3 feet deep. What is the clarifier
detention time in hours? Answer: What is the clarifier detention
CERTIFICATION EVALUATION TEST 2026 FULL
QUESTIONS AND CORRECT ANSWERS
ALREADY PASSED GRADED A+
◉ Which of activated sludge has two aeration basins per single
treatment unit? Answer: Contact stabilization
◉ 27. A complete mix activated sludge plant has a fast settling
sludge and high amounts of pin floc leaving the clarifier. One method
of correcting the problem is to Answer: Increase F/M ratio by
wasting more
◉ problem is Testing of mixed liquor indicates the MLSS is 2500
mg/L and the settling test shows that a 1000 ml sample settles to
400 mls after 30 minutes. What is the SVI? 400 x 1000 2500 160
Answer: 160
◉ In the problem above, what the sludge quality? Answer: Bulking
◉ Which activated sludge process has 18 to 20 + hours detention
time in the aeration basin? Answer: Extended air
,◉ What is the minimum clearance from the sidewall of a pipe to the
trench wall in an excavation? Answer: 4 inches
◉ What is the definition of pH? Answer: The logarithm of the
reciprocal of the hydrogen ion concentration The negative logarithm
of the hydrogen ion concentration
◉ How often should pH meters be calibrated? Answer: Daily
◉ trench is 4,100 feet long, four 4 wide and 6 feet deep. There is a
12-inch diameter pipe in the bottom of the trench. How many cubic
yards of material were removed from the trench? 4x6x4,100 3,644
27 Answer: 3,644
◉ In the problem above, how many cubic yards of material will be
required to fill the trench? 3.14x0.5 x0.5 x 4,100 =119cu yds 27
3,644 -119 = 3,525 Answer: 3,525
◉ What is the standard chlorine residual and contact time on Texas
discharge permits? Answer: e. None of the above organization
increases,
◉ As the complexity of an organization increases, what management
function becomes most important? Answer: Planning
, ◉ The following scenario is to be used in answering questions 38,
39, and 40. A pump with a 15-inch impeller is running at 1170 RPM
s, with pump efficiency of 75%, and is pumping 500 gpm with 75
feet of head. If the RPM of the pump is increased to 1750 RPMS
calculate the following: New output in gpm: Answer: 1750 1770 =F =
1.5 500 x 1.5 = 750 gpm 750
◉ New head in feet: 75 x 1.5 x 1.5 = 168.75 Answer: 170
◉ New horsepower required: Answer: 750 x 170 - 43 3960 x 0.75 a.
43
◉ What compound or compounds are formed when Cl, combines
with water? Answer: Both a and d
◉ When chlorinating treated wastewater, what chlorine residual do
we test for? Answer: Chloramine and Total
◉ What is the standard pH range on Texas effluent discharge
permits? Answer: b. 6.0 to 9.0
◉ A wastewater treatment plant has a clarifier that is 80 feet in
diameter and is 12 feet deep. The flow is 2.5 mgd. The single weir is
two feet inside the outer wall and is 3 feet deep. What is the clarifier
detention time in hours? Answer: What is the clarifier detention
