Which test is typically never performed on wastewater influent?

The test that is typically never performed on wastewater influent is the determination of fecal coliform. This is because fecal coliform testing is primarily concerned with assessing the presence of specific bacteria that indicate fecal contamination and potential pathogen presence, which is usually more relevant in treated effluents or surface water monitoring rather than in influent wastewater.

In wastewater treatment, influent is composed of a mixture of various materials and contaminants that have yet to undergo any treatment processes. While BOD (Biochemical Oxygen Demand), suspended solids, and pH are essential parameters used to evaluate the characteristics of influent, their measurements provide insights into the organic load, solids content, and acidity/alkalinity of the water that needs treatment. On the other hand, testing for fecal coliform bacteria is more applicable for understanding the quality of treated effluent or the receiving waters, where the evaluation of microbial hygiene is crucial for assessing environmental and public health risks.