WTO Math 2

Question 1

A storage tank is 30 feet in diameter and 20 feet tall. What is its volume in gallons? (1 ft³ = 7.48 gal)

Accepted Answer

105,640 gal

Answer

Volume = π × r² × h = 3.1416 × 15² × 20 = 14,137 ft³ × 7.48 = 105,745 gal ≈ 105,640 gal.

Question 2

A pump delivers 500 gpm. How many hours will it take to fill a 750,000-gallon reservoir?

Accepted Answer

25 hours

Answer

Time = 750,000 ÷ 500 = 1,500 minutes ÷ 60 = 25 hours.

Question 3

A water main is 12 inches in diameter and 1,000 feet long. What volume of water does it hold in gallons?

Accepted Answer

5,875 gal

Answer

Volume = π × (0.5 ft)² × 1,000 ft = 785.4 ft³ × 7.48 = 5,875 gal.

Question 4

A treatment plant adds 4.5 mg/L of chlorine to a flow of 2.8 MGD. How many pounds of chlorine are used per day?

Accepted Answer

105.3 lb/day

Answer

lbs/day = 4.5 × 2.8 × 8.34 = 105.3 lb/day.

Question 5

Convert 2.5 cubic feet per second (cfs) to gallons per minute (gpm).

Accepted Answer

1,122 gpm

Answer

2.5 cfs × 448.8 = 1,122 gpm.

(WTO) Water Treatment Operator Certification Practice Test