Circumference, Area, and Volume - Basic Mathematics for Water and Wastewater Operators - page 173

■ Example 11.35
Problem : How many gallons of water can a barrel hold if it measures 4 ft in diameter
and can hold water to a depth of 4 ft?
Solution:
Volume = 0.785 × D 2 × Height = 0.785 × (4 ft) 2 × 4 ft = 50.24 ft 3
50.24 ft 3 × 7.48 gal l /f ft3 3 = 375.8 gal
■ Example 11.36
Problem: A water main needs to be disinfected. The main is 42 inches in diameter
and has a length of 0.33 miles. How many gallons of water will it hold?
Solution:
42 in. = 3.5 ft
0.33 mile × 5280 ft/mile = 1742.4 ft
Volume = 0.785 × D 2 × Height = 0.785 × (3.5 ft) 2 × 1742.4 ft = 16,755.35 ft 3
16,755.35 ft 3 × 7.48 gal l /f ft3 3 = 125,330.04 gal
■ Example 11.37
Problem : A 5-million-gallon storage tank is 5% full. How many gallons does it
contain?
Solution:
5,000,000 gal × 0.05 = 250,000 gal
■ Example 11.38
Problem: What is 11% of a 1.5-million-gallon tank?
Solution:
1.5 MG × 0.11 = 0.165 MG