A clarifier that is 150 ft long, 50 ft wide, and 10 ft deep treats a flow of 4.0 MCD. What is its detention time in hours?

To determine the detention time in a clarifier, it's essential to use the formula that relates the volume of the clarifier to the flow rate being treated. The formula for detention time is:

Detention Time (hours) = Volume of the clarifier (cubic feet) / Flow rate (cubic feet per hour)

First, we need to calculate the volume of the clarifier. The volume is calculated using the dimensions provided:

Volume = Length × Width × Depth

Volume = 150 ft × 50 ft × 10 ft

Volume = 75,000 cubic feet

Next, we must convert the flow rate into cubic feet per hour. The problem states that the flow rate is 4.0 million cubic feet per day (MCD). To convert this into cubic feet per hour, you would perform the following calculation:

4.0 MCD = 4,000,000 cubic feet/day

To convert days to hours:

4,000,000 cubic feet/day ÷ 24 hours/day = 166,666.67 cubic feet/hour

Now, we can substitute the values into the detention time formula:

Detention Time = Volume / Flow Rate

Detention Time = 75,000 cubic feet /