What are the two types of composite samples used in wastewater analysis?

The correct response identifies the two types of composite samples in wastewater analysis as time-based and flow proportional samples. Time-based composite sampling involves collecting samples at predetermined intervals over a specific period. This approach ensures that variations in wastewater quality over time are captured, providing a more representative overview of the effluent characteristics throughout the sampling period.

On the other hand, flow proportional sampling involves collecting samples based on the flow rate of the wastewater. In this method, the volume of sample collected is proportional to the flow rate at different times, which helps reflect the variations in both the quality and quantity of wastewater.

Together, these methods offer a comprehensive representation of wastewater characteristics and help in accurately assessing the overall quality of effluents. This detailed approach is essential for regulatory compliance and monitoring the impact of wastewater on the environment.

Other options focus on different sampling methodologies; however, they do not specifically describe the composite sampling types used in wastewater analysis.