California Wastewater Treatment Operator Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Prepare for the California Wastewater Treatment Operator Exam with our comprehensive quiz featuring detailed questions, hints, and explanations tailored to help you excel. Get ready to master the essential concepts and practical knowledge required for certification!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.


What is the typical removal efficiency of settleable solids in a primary clarifier?

  1. 75 to 80%

  2. 80 to 85%

  3. 90 to 95%

  4. 95 to 99%

The correct answer is: 95 to 99%

The typical removal efficiency of settleable solids in a primary clarifier is generally considered to be in the range of 90 to 95%. Primary clarifiers are designed to remove a significant portion of the solids in wastewater through the process of sedimentation. While highly effective, the range you’ve selected is on the higher end of the scale, which can vary depending on several factors, such as the design of the clarifier, the characteristics of the influent wastewater, and the operational conditions. Most primary clarifiers can achieve around 90 to 95% efficiency under optimal conditions; however, in standard practice, the range often cited for average performance is closer to 80 to 85%. Therefore, while the higher efficiency scenario is attainable, the more typical performance in the field leans towards the lower percentage. This variability is essential for operators to understand, as it guides their expectations and operational adjustments.