Which unit is commonly used to express the flow rate of wastewater in treatment plants?

The unit commonly used to express the flow rate of wastewater in treatment plants is the million gallons per day (MGD). This measurement is particularly relevant in the context of wastewater treatment because it provides a clear understanding of the volume of wastewater being processed over a full day. Using MGD allows for easy comparison between the treatment capacities of different plants and enables operators to make informed decisions about treatment processes, equipment sizing, and operational efficiency.

In the context of wastewater management, MGD is favored due to the typical scale of wastewater treatment operations in the United States, where the volumes can reach into millions of gallons. This unit also aligns well with the standards and reporting practices used by many regulatory agencies.

Other units like liters per hour (LPH), gallons per hour (GPH), and million liters per day (MLD) are less common in American facilities, though they may be used in different contexts or regions. MGD remains the standard in most U.S.-based wastewater treatment discussions, making it the appropriate choice for expressing flow rates in this setting.