Practice Test Geeks(WTO) Water Treatment Operator Certification Practice Test
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Math Flashcards

7 cards from real WTO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Math flashcards as text

  1. A filter has a surface area of 400 ft² and a flow rate of 1,600 gpm. What is the filtration rate in gpm/ft²?

    Answer: 4 gpm/ft²

    Filtration rate = 1,600 gpm ÷ 400 ft² = 4 gpm/ft².

  2. A settling basin is 60 ft long, 20 ft wide, and 10 ft deep. What is its volume in gallons?

    Answer: 89,760 gal

    Volume = 60 × 20 × 10 = 12,000 ft³ × 7.48 = 89,760 gallons.

  3. The plant flow is 4.2 MGD. Express this flow in gallons per minute (gpm).

    Answer: 2,917 gpm

    4.2 × 1,000,000 ÷ 1,440 min/day = 2,917 gpm.

  4. A 10% sodium hypochlorite solution is needed to deliver 6 lbs of chlorine. How many gallons of solution are required?

    Answer: 7.19 gal

    6 lbs ÷ (0.10 × 8.34 lb/gal) = 6 ÷ 0.834 = 7.19 gallons.

  5. A pump runs 14 hours per day and delivers 350 gpm. How many million gallons does it deliver in 30 days?

    Answer: 8.82 MGD

    350 × 14 × 60 × 30 = 8,820,000 gal = 8.82 MG total.

  6. A water sample has a turbidity of 0.8 NTU before filtration and 0.04 NTU after. What is the percent removal?

    Answer: 95%

    % removal = (0.8 − 0.04) ÷ 0.8 × 100 = 95%.

  7. The detention time in a contact chamber is required to be at least 30 minutes at a flow of 5 MGD. What minimum volume (in gallons) is needed?

    Answer: 104,167 gal

    Flow = 5,000,000 ÷ 1,440 = 3,472 gpm; volume = 3,472 × 30 = 104,167 gal.