California Wastewater Treatment Operator Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

High levels of Biochemical Oxygen Demand (BOD), Total Suspended Solids (TSS), or residual pollutants in the effluent are definitive indicators of poor wastewater treatment performance. BOD measures the amount of oxygen that micro-organisms will consume while decomposing organic matter in water, and high levels suggest that there is an abundance of organic waste that is not being adequately treated. TSS represents the solid particles suspended in water, and elevated TSS can indicate inefficient settling processes or inadequate filtration.

Residual pollutants in the effluent signal that harmful substances have not been sufficiently removed during treatment, which could lead to environmental harm if released. Collectively, these signs reflect inefficiencies or failures within the treatment process, highlighting the system's inability to meet treatment standards required for safe discharge into the environment. Monitoring these parameters is crucial for ensuring compliance with regulatory requirements and protecting aquatic ecosystems.

The other options indicate issues that could be involved in the operational aspects of treatment but do not directly reflect the effectiveness of the treatment process itself as indicated by pollutant levels. Low temperatures in aeration tanks may affect microbial activity but are not as definitive on their own, while frequent maintenance of flow meters is part of routine operations and does not directly correlate with treatment efficacy. Increased algae growth