Question 9004 of 234 · California Wastewater Operator Exam
A rectangular tank is 60 ft long, 20 ft wide, and 10 ft deep. Flow is 1.5 MGD. What is the detention time in hours?
Exactly one answer is correct.
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Correct answer to question 9004
- D: 1.4 hours
Explanation
Volume = 60 x 20 x 10 = 12,000 ft3 x 7.48 = 89,760 gal. Detention time = 89,760 / 1,500,000 gal/day x 24 hr/day = 1.4 hours. Forgetting to convert cubic feet to gallons, or leaving the result in days, are common errors.
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