What is the total volume of a grit chamber designed to handle an average daily flow of 3 million gallons with a peak flow ratio of 2.5, and a detention time of 3 minutes?
Explanation
Answer: C - The total volume of the grit chamber is 2,079 ft3 is required to handle an average flow of 3 million gallons per day (mgd), with a peak flow ratio of 2.5 with a detention time of 3 minutes.
Solution: Volume of grit chamber = Peak Flow x detention time
Where, peak flow = average flow x peak flow ratio
= 3 mgd x 2.5
= 7.5 mgd
Given, 1 mgd = 1.54 ft3/seconds (sec)
Volume = 7.5 mgd x 1.54 ft3/sec x 3 minutes x 60 sec/minute
= 2,079 ft3
