How is the performance of a waste treatment plant best measured?

The performance of a wastewater treatment plant is best measured by the quality of the effluent because the primary goal of such facilities is to treat wastewater to a level that is safe for discharge into the environment or for reuse. The effluent quality determines how effectively the plant removes contaminants, meets regulatory compliance, and protects public health and the environment.

Focusing on effluent quality involves measuring parameters like biochemical oxygen demand (BOD), total suspended solids (TSS), nitrogen, phosphorus, pathogens, and more. High-quality effluent indicates that the treatment processes are functioning properly and are effective in removing pollutants.

While the speed of processing, cost-efficiency of operations, and volume of waste processed are important operational considerations, they do not inherently reflect how well the treatment plant is protecting water quality and public health, which is ultimately the main purpose of wastewater treatment. Thus, these factors can be secondary to evaluating the effectiveness of the facility in delivering clean and safe outflow.