California Wastewater Treatment Operator Practice Exam 2026 - Free Wastewater Treatment Operator Practice Questions and Study Guide

The primary function of a settling tank is to remove solid particles through sedimentation. This process allows heavier solids, known as sludge, to settle at the bottom of the tank due to gravity, thereby clarifying the liquid above. The primary goal is to reduce the concentration of suspended solids in the wastewater prior to any further treatment processes. By effectively separating these solids, settling tanks help enhance the overall efficiency of wastewater treatment, ensuring that only clarified water moves on to subsequent stages.

Aeration, biological treatment initiation, and water storage are important aspects of wastewater treatment but occur at different stages or in different systems. Aeration is primarily related to oxygenating the water to promote aerobic biological processes, while biological treatment focuses on the breakdown of organic matter through microbial activity. Storing treated water is a separate function that usually occurs after water has undergone the necessary treatment processes, unlike the settling tank's direct role in the preliminary separation of solids.