What is the clarifier detention time in hours for a wastewater treatment plant with a flow of 2.5 mgd?

To determine the clarifier detention time for a wastewater treatment plant, one needs to consider the volume of the clarifier and the flow rate of the influent wastewater. Clarifier detention time is calculated using the formula:

[ \text{Detention Time (hours)} = \frac{\text{Volume of Clarifier (gallons)}}{\text{Flow Rate (gallons per minute)}} \times \frac{1 \text{ hour}}{60 \text{ minutes}} ]

In this scenario, the flow rate is given as 2.5 million gallons per day (mgd). To work with this figure in the standard detention time formula, it's essential to convert mgd to gallons per minute (gpm):

[ 2.5 \text{ mgd} = \frac{2.5 \times 1,000,000 \text{ gallons}}{24 \text{ hours} \times 60 \text{ minutes}} \approx 1731.48 \text{ gpm} ]

Then, to find the correct detention time, one would need to know the volume of the clarifier. If we assume a typical volume for a medium-sized clarifier is adequate (for illustrative purposes,