TX Class C Wastewater Treatment License Questions with correct Answers (A+ GRADED 100% VERIFIED)| 2025/2026

TX Class C Wastewater Treatment
License
Question 1: What is the % reduction formula?

●​ A) outgoing/incoming X 100
●​ B) incoming - outgoing/incoming X 100
●​ C) incoming + outgoing/incoming X 100
●​ D) incoming X outgoing/100

Answer: B) incoming - outgoing/incoming X 100



Question 2: 1 acre equals:

●​ A) 40,000 ft squared
●​ B) 43,560 ft squared
●​ C) 50,000 ft squared
●​ D) 45,000 ft squared

Answer: B) 43,560 ft squared



Question 3: 1 acre will treat approximately how many pounds of BOD?

●​ A) 25 lb
●​ B) 30 lb
●​ C) 35 lb
●​ D) 40 lb

Answer: C) 35 lb



Question 4: 1 day equals how many minutes?

●​ A) 1200 minutes
●​ B) 1440 minutes
●​ C) 1600 minutes
●​ D) 1800 minutes

Answer: B) 1440 minutes

,Question 5: 1 gallon of water weighs:

●​ A) 7.48 pounds
●​ B) 8.00 pounds
●​ C) 8.34 pounds
●​ D) 9.00 pounds

Answer: C) 8.34 pounds



Question 6: 1 Liter equals:

●​ A) 500 milliliters (mL)
●​ B) 750 milliliters (mL)
●​ C) 1000 milliliters (mL)
●​ D) 1250 milliliters (mL)

Answer: C) 1000 milliliters (mL)



Question 7: 1 mg/L equals:

●​ A) 1 parts per billion (ppb) in water
●​ B) 1 parts per million (ppm) in water
●​ C) 1 parts per thousand (ppt) in water
●​ D) 10 parts per million (ppm) in water

Answer: B) 1 parts per million (ppm) in water



Question 8: 1 MGAD equals:

●​ A) 20 gpd/ft cubed
●​ B) 23 gpd/ft cubed
●​ C) 25 gpd/ft cubed
●​ D) 27 gpd/ft cubed

Answer: B) 23 gpd/ft cubed



Question 9: 1 mL of water weighs:

, ●​ A) 1 milligram (mg)
●​ B) 1 gram (g)
●​ C) 1 kilogram (kg)
●​ D) 10 grams (g)

Answer: B) 1 gram (g)



Question 10: 1,000,000 gallons per day equals:

●​ A) 1 GPD
●​ B) 1 KGD
●​ C) 1 MGD
●​ D) 1 BGD

Answer: C) 1 MGD



Question 11: 27 ft cubed equals:

●​ A) 1 foot cubed
●​ B) 1 yard cubed
●​ C) 1 meter cubed
●​ D) 1 acre cubed

Answer: B) 1 yard cubed



Question 12: 43,560 ft cubed equals:

●​ A) 1 acre-ft
●​ B) 1 yard-ft
●​ C) 1 mile-ft
●​ D) 1 hectare-ft

Answer: A) 1 acre-ft



Question 13: 7.48 gallons equals:

●​ A) 1 yard cubed
●​ B) 1 meter cubed
●​ C) 1 ft cubed
●​ D) 1 liter

, Answer: C) 1 ft cubed



Question 14: 8.34 lb in 1 MG of water equals:

●​ A) 1 ppb (parts per billion)
●​ B) 1 ppm (parts per million)
●​ C) 1 ppt (parts per thousand)
●​ D) 10 ppm (parts per million)

Answer: B) 1 ppm (8.34 lb/8,340,000)



Question 15: A BOD test is:

●​ A) a minor parameter in quality control
●​ B) only used for drinking water
●​ C) a major parameter in quality control
●​ D) not important in wastewater treatment

Answer: C) a major parameter in quality control



Question 16: A buildup of solids in the tank of the rotating biological contactor
may be caused by:

●​ A) excessive aeration
●​ B) poor primary clarification
●​ C) high temperature
●​ D) low pH only

Answer: B) poor primary clarification



Question 17: A cause of poor quality supernatant liquor could be:

●​ A) digester underload
●​ B) digester overload
●​ C) excessive mixing
●​ D) low temperature only

Answer: B) digester overload