Which abbreviation represents flow rate in millions of gallons per day?

• A. GPM
• B. MGD
• C. Mgd
• D. CFS

Answer: (B)

Flow rate units depend on the time basis you’re using. For a quantity expressed as millions of gallons per day, the standard abbreviation is MGD. It specifically denotes million gallons each day and is the common way to report daily production or demand in water systems. Other units serve different time scales: GPM means gallons per minute, which is a rate measured every minute and not tied to daily total; CFS stands for cubic feet per second, using a different volume unit and a per-second basis. The lowercase variant Mgd isn’t the conventional notation, so the widely accepted form is MGD. For example, a facility producing 5 MGD means five million gallons each day.