What factors do POTWs use to assess surcharges on industrial discharges?

Publicly Owned Treatment Works (POTWs) commonly assess surcharges on industrial discharges based on factors that indicate the strength and impact of those discharges on the wastewater treatment process. The correct factors to consider in this context include Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Flow, and Suspended Solids (SS).

BOD measures the amount of oxygen that microorganisms will consume while decomposing organic matter in water, which gives an indication of the organic pollution level. COD is another crucial parameter that measures the total quantity of oxygen required to chemically oxidize organic and inorganic substances in water, providing a broader picture of water quality compared to BOD.

Flow is essential for understanding the volume of wastewater entering the treatment facility, while suspended solids reflect the particulate matter present, which can affect treatment efficiency and operational costs. Together, these metrics help POTWs determine the degree of impact an industrial facility has on the treatment process and establish appropriate surcharges based on that impact.