How is PPMV calculated?

To calculate PPMV, which stands for parts per million volume, you need to determine how many parts of a substance (in this case, the chemical) are present in a certain volume of water. The formula provided is structured to quantify this in a way that effectively relates the concentration to volume.

The formula, expressed as (gallons of chemical multiplied by 1,000,000) divided by the product of cubic feet per second (CFS), the conversion factor (450), and the number of minutes applied, allows for this calculation.

To break it down:

• The 'gallons of chemical' quantifies the total volume of the pesticide being applied, which is essential for understanding how concentrated the solution will be in the water body being treated.

• Multiplying by 1,000,000 serves to convert the concentration into parts per million, which is a standard unit for expressing low concentrations.

• The denominator combines the flow rate (CFS) with a conversion factor and the time duration, providing a measurement of the total volume of water interacting with the applied chemical over that period.

This ratio effectively gives you a straightforward way to calculate how many parts of the chemical exist per million parts of the treated water,