Which of the following best explains the process of calculating the average alum dosage in mg/L?

The process of calculating the average alum dosage in mg/L involves determining how much alum is added to the treated water relative to the volume of water being treated. The correct approach is to sum the total pounds of alum added during a specific time period and then divide that total by the total gallons of water that have been treated in the same period. This division provides the alum dosage in terms of milligrams per liter (mg/L), which is a common unit used in water treatment processes.

This method ensures that the average dosage reflects the actual use of alum in relation to the volume of water being processed, which is essential for maintaining effective treatment levels. It allows operators to monitor and adjust the alum dosage based on treatment performance and other factors, ensuring optimal water quality.

The other choices suggest methods that do not accurately reflect the correct calculation of average alum dosage or use values inappropriately, leading to potential inaccuracies in treatment assessments.