Massachusetts Wastewater Practice Exam

Which of the following is not a detrimental effect of industrial wastewater on a POTW?

1. Pass-through

2. Corrosion

3. Toxicity

4. Equalization

The correct answer is: Equalization

Equalization is a process in wastewater treatment where flows and loadings are balanced over time to ensure that the treatment facility operates efficiently and effectively. This process helps to manage fluctuations in the volume and constituents of wastewater that a treatment plant receives. It is typically used to prevent harmful spikes in pollutants from overwhelming the system, ensuring a more stable and treatable inflow of wastewater. In contrast, pass-through, corrosion, and toxicity are all detrimental effects that industrial wastewater can have on a Publicly Owned Treatment Works (POTW). Pass-through refers to the situation where pollutants are not removed in the treatment process and end up being discharged into the receiving water bodies, potentially harming aquatic ecosystems. Corrosion refers to the wear and damage to treatment plant infrastructure due to aggressive substances often found in industrial wastewater, which can lead to costly repairs and disruptions in service. Toxicity involves harmful effects on the microorganisms used in the treatment process, which can diminish the efficiency of wastewater treatment and may lead to permit violations. Therefore, equalization, as a method to balance and stabilize the treatment processes, does not have a negative impact in the way the other choices do. Rather, it serves a vital role in enhancing the overall performance of a POTW.