When faced with a licensing exam, don't struggle with test anxiety! Use the question below and others from our Exam Study Guide series to properly study and prepare for exam questions. Take a look at this sample wastewater treatment licensing question along with an explanation of the correct answer.

Sample question:

What can happen if the temperature of your digester varies more than 1 or 2 degrees C over a few days?

A) Nothing

B) Digester upset

C) Struvite deposits

D) Toxic acid imbalance

Answer: 

Temperature-related stress is caused by a change in digester temperature of more than 1 or 2 degrees C (2 or 3 degrees F) in less than 10 days, which would reduce the biological activity of the methane-forming microorganisms. Therefore the answer is B, digester upset.

Source: WEF MOP 11 30-65

About the author
Ricky Lallish is the Water Pollution Control, Program Director at the Environmental Resources Training Center of Southern Illinois University Edwardsville. He provides training for entry level operators in the wastewater field and operators throughout the state looking to further their education.