What is the detention time in minutes for a basin that measures 175 feet by 40 feet by 20 feet with a flow of 8 MGD?

To determine the detention time for a basin, you need to first calculate the volume of the basin and then divide that volume by the flow rate.

The volume of the basin can be calculated using the formula for the volume of a rectangular prism:

Volume = length × width × height.

In this case, the basin measures 175 feet by 40 feet by 20 feet:

Volume = 175 ft × 40 ft × 20 ft = 140,000 cubic feet.

Next, we need to convert the flow from million gallons per day (MGD) to cubic feet per minute (CFM). One MGD is equivalent to approximately 7.48 cubic feet per second. Since there are 86,400 seconds in a day, we can convert the flow through the following steps:

8 MGD × 7.48 cubic feet (per gallon) = 59.84 cubic feet per second.

Now, to convert this to cubic feet per minute:

59.84 CFS × 60 seconds = 3,590.4 CFM.

Now that we have both the volume of the basin and the flow rate, we can calculate the detention time. The detention time is determined by the volume of the