WASTEWATER CLASS B TX 2026 CORE EXAM TEST
QUESTIONS AND ANSWERS GRADED A+
✔✔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 - ✔✔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 - ✔✔3,525
✔✔What is the standard chlorine residual and contact time on Texas discharge
permits? - ✔✔e. None of the above organization increases,
✔✔As the complexity of an organization increases, what management function
becomes most important? - ✔✔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: - ✔✔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 - ✔✔170
✔✔New horsepower required: - ✔✔750 x 170 - 43 3960 x 0.75 a. 43
✔✔What compound or compounds are formed when Cl, combines with water? -
✔✔Both a and d
✔✔When chlorinating treated wastewater, what chlorine residual do we test for? -
✔✔Chloramine and Total
✔✔What is the standard pH range on Texas effluent discharge permits? - ✔✔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? - ✔✔What is the clarifier detention
time in hours? 2,500,000 gpd - 104,167 gph 24 hrs/day 3.14 x 40 x 40 x 9 x 7.48 gal
3.14 x 36 x 36 x 3 x 7.48 = 91,318 338,216 + 91,318 429,534 gallons 429,534 gals =
4.1 hrs 104,167 gph 4.1
, ✔✔What is the hydraulic loading on the clarifier in gal/sq ft/day? - ✔✔3.14 x 38 x 38 =
4,534 sq ft 2,500,000 gpd = 551 gal / sq ft I day 4,534 sq ft 551
✔✔What is the weir loading in gal/linear ft/day? 3.14 x 76 = 239 ft of weir 2,500,000 gpd
= 10,460 gal / lin ft / day 239 ft weir - ✔✔10,460
✔✔In Texas, an oxidation ditch treatment plant is referred to as - ✔✔Racetrack
✔✔In Texas, pH meters are required to be calibrated on how many buffers? - ✔✔two
✔✔An industrial complex has a BOD discharge to the POTW of 500 pounds per
population equivalent of this industry is - ✔✔500 lbs - 2,941 0.17 lbs BOD/ person 2941
✔✔What substance will interfere with a DPD chlorine test? - ✔✔Manganese
✔✔The parameters of the BOD test are - ✔✔5 days at 20° Centigrade
✔✔An Imhoff tank is what type of treatment process? - ✔✔Primary
✔✔Standard Dimension Ratio in pve pipe is defined as - ✔✔Ratio of OD pipe diameter
to wall thickness
✔✔MSDS sheets must be kept for how many years after you have stopped using the
chemical? - ✔✔c. 30
✔✔A pneumatic ejector is - ✔✔a. a lift station pumping device
✔✔How should shoring be removed from a trench? - ✔✔d. from the bottom up
✔✔57. The most common pump used in the collection system is - ✔✔d. centrifugal
✔✔In low pressure sewer systems where each tap must have a grinder pump lift
station, the lift station is considered to be - ✔✔Part of the collection system and the
responsibility of the utility
✔✔Effective communication depends on - ✔✔being a good listener
✔✔A construction site safety evaluation checklist must include - ✔✔a. placement of
equipment, vehicles, and spoil bank b. placement of flaggers, barricades, cones and
other safety equipment c. use of warning signs
✔✔When designing a wastewater collection system, the engineer considers the
population for how many years in the future? - ✔✔50
QUESTIONS AND ANSWERS GRADED A+
✔✔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 - ✔✔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 - ✔✔3,525
✔✔What is the standard chlorine residual and contact time on Texas discharge
permits? - ✔✔e. None of the above organization increases,
✔✔As the complexity of an organization increases, what management function
becomes most important? - ✔✔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: - ✔✔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 - ✔✔170
✔✔New horsepower required: - ✔✔750 x 170 - 43 3960 x 0.75 a. 43
✔✔What compound or compounds are formed when Cl, combines with water? -
✔✔Both a and d
✔✔When chlorinating treated wastewater, what chlorine residual do we test for? -
✔✔Chloramine and Total
✔✔What is the standard pH range on Texas effluent discharge permits? - ✔✔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? - ✔✔What is the clarifier detention
time in hours? 2,500,000 gpd - 104,167 gph 24 hrs/day 3.14 x 40 x 40 x 9 x 7.48 gal
3.14 x 36 x 36 x 3 x 7.48 = 91,318 338,216 + 91,318 429,534 gallons 429,534 gals =
4.1 hrs 104,167 gph 4.1
, ✔✔What is the hydraulic loading on the clarifier in gal/sq ft/day? - ✔✔3.14 x 38 x 38 =
4,534 sq ft 2,500,000 gpd = 551 gal / sq ft I day 4,534 sq ft 551
✔✔What is the weir loading in gal/linear ft/day? 3.14 x 76 = 239 ft of weir 2,500,000 gpd
= 10,460 gal / lin ft / day 239 ft weir - ✔✔10,460
✔✔In Texas, an oxidation ditch treatment plant is referred to as - ✔✔Racetrack
✔✔In Texas, pH meters are required to be calibrated on how many buffers? - ✔✔two
✔✔An industrial complex has a BOD discharge to the POTW of 500 pounds per
population equivalent of this industry is - ✔✔500 lbs - 2,941 0.17 lbs BOD/ person 2941
✔✔What substance will interfere with a DPD chlorine test? - ✔✔Manganese
✔✔The parameters of the BOD test are - ✔✔5 days at 20° Centigrade
✔✔An Imhoff tank is what type of treatment process? - ✔✔Primary
✔✔Standard Dimension Ratio in pve pipe is defined as - ✔✔Ratio of OD pipe diameter
to wall thickness
✔✔MSDS sheets must be kept for how many years after you have stopped using the
chemical? - ✔✔c. 30
✔✔A pneumatic ejector is - ✔✔a. a lift station pumping device
✔✔How should shoring be removed from a trench? - ✔✔d. from the bottom up
✔✔57. The most common pump used in the collection system is - ✔✔d. centrifugal
✔✔In low pressure sewer systems where each tap must have a grinder pump lift
station, the lift station is considered to be - ✔✔Part of the collection system and the
responsibility of the utility
✔✔Effective communication depends on - ✔✔being a good listener
✔✔A construction site safety evaluation checklist must include - ✔✔a. placement of
equipment, vehicles, and spoil bank b. placement of flaggers, barricades, cones and
other safety equipment c. use of warning signs
✔✔When designing a wastewater collection system, the engineer considers the
population for how many years in the future? - ✔✔50
