A sedimentation basin has a flow of 0.5 million gallons per day and surface area 2,000 ft². What is the loading rate in gpd/ft²?

A sedimentation basin has a flow of 0.5 million gallons per day and surface area 2,000 ft². What is the loading rate in gpd/ft²?

• A. 0.25
• B. 125
• C. 250
• D. 2,000

Answer: (C)

Loading rate tells you how much water passes through each square foot of surface per day. To find it, divide the total daily flow by the surface area. Here, 0.5 million gallons per day equals 500,000 gpd, and the basin area is 2,000 ft². So 500,000 ÷ 2,000 = 250 gpd per ft². The loading rate is 250 gpd/ft².

Loading rate tells you how much water passes through each square foot of surface per day. To find it, divide the total daily flow by the surface area. Here, 0.5 million gallons per day equals 500,000 gpd, and the basin area is 2,000 ft². So 500,000 ÷ 2,000 = 250 gpd per ft². The loading rate is 250 gpd/ft².