When conducting PDI of a waste water system, when should the flow test be conducted in relation to the flood test?

The flow test should be conducted before the flood test when performing a Pre-Delivery Inspection (PDI) of a wastewater system. Conducting the flow test prior to the flood test is essential for assessing the system's ability to handle normal operating conditions without the risk of overflow or backup. This sequence allows for identifying any potential issues in the flow capacity and unobstructed pathway of the wastewater system.

By first determining the system's flow characteristics, engineers and inspectors can ensure that it is operating correctly and efficiently under typical load scenarios. Conducting the flood test afterward helps assess the system's performance under a simulated extreme condition, such as excessive inflow or stormwater events, without the interference of existing flow issues. This logical progression helps ensure that the wastewater system is thoroughly evaluated and capable of managing both regular and peak demands. It lays a foundation of confidence in the system's performance before testing its resilience under more severe conditions.