What should be done to capture the typical flow in a wastewater sample?

To capture the typical flow in a wastewater sample, using composite sampling methods is the most effective approach. Composite sampling involves collecting multiple aliquots of wastewater over a specified period and then combining them into a single sample. This method effectively represents the variability in wastewater flow and concentration that can occur throughout the day, ensuring that the sample reflects the average conditions rather than isolated or fluctuating events.

By utilizing composite samples, inspectors can gain insights into the overall performance of wastewater treatment processes, detect any trends over time, and assess compliance with discharge regulations more accurately. This methodology is particularly important in environments where flow can significantly vary due to factors such as industrial discharges, stormwater, or changes in population.

The other methods mentioned do not provide a comprehensive representation of the wastewater flow. Sampling only hourly flow can miss variations that occur between those hourly samples. Random sampling times may not capture patterns, leading to potential inaccuracies. Focusing solely on peak times does not account for low flow periods, which can also be significant in understanding overall system performance and compliance. Thus, composite sampling stands out as the best practice for obtaining a representative wastewater sample.