When calculating a flow weighted composite sample, what is the total volume needed from a discharge of 1200 gpd if other discharges are also included?

When calculating a flow-weighted composite sample, it's important to consider the total volume of water needed to ensure that the sample accurately reflects the concentration of constituents in the discharge over time. In this case, if the discharge rate is 1200 gallons per day (gpd), the total volume necessary will be influenced by how the flow-weighted sampling is carried out.

A common approach in environmental sampling is to use a proportionate volume related to the flow rate of the discharge. If the objective is to represent the discharge accurately, a larger volume is generally required to capture a more representative sample over a specified period.

In this scenario, the choice of 2400 mL aligns with standard sampling practices that suggest using a volume that is often tied to the flow rate of the discharge, thereby ensuring a meaningful composite sample. The flow-weighted composite sampling approach emphasizes the need for a volume that is sufficiently large relative to the discharge rate, especially when combining multiple discharges, enhancing the representativeness of the sample.

The other volumes proposed do not provide an adequate representation based on the typical practices of calculating sample volumes corresponding to higher discharge rates like 1200 gpd. Therefore, the selection of 2400 mL signifies a thorough and appropriate choice in