Which factor is NOT included in the PPMV formula calculation?

The PPMV formula, which stands for Parts Per Million Volume, is primarily focused on measuring the concentration of a chemical in a given volume of water over a specific time period. This formula helps in determining the effectiveness of a pest control method and ensures that the chemical is applied in a safe and effective manner.

The calculation typically requires factors such as the amount of chemical used (measured in gallons), the flow rate expressed in cubic feet per second (CFS), and the duration of application (in minutes). These three elements directly influence the concentration of the chemical in the water being treated.

The cross-sectional area, while relevant in other contexts of fluid dynamics and flow calculations, is not explicitly included in the PPMV formula. Therefore, it is not a factor needed for calculating the concentration of the chemical in the water over the specified time. This makes the cross-sectional area the correct choice when identifying what is NOT included in the PPMV formula calculation.