Welcome back to TPO magazine's Exam Study Guide Series, which offers a pair of water/wastewater study questions with in-depth explanations of the answers. Last time, we covered a set of wastewater and drinking water treatment questions on the topics of Wastewater Sample Testing and Chemical Dilutions. This time you can test your knowledge about electrical current imbalance and chemical reactions.

Wastewater Treatment Sample Question

Under normal operating conditions, what is the maximum acceptable current imbalance?

A. No voltage imbalance is acceptable 
B. 2%
C. 5%
D. 10%

Water Treatment Sample Question

Aluminum sulfate reacts with alkalinity to form insoluble floc. Which reaction indicates a balanced chemical reaction?

To see answers for both of the above questions, click this link.

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About the authors: Rick Lallish is the Water Pollution Control program director at the Environmental Resources Training Center (ERTC) 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. Lallish was also named the 2017 Illinois Operator of the Year and 2018 president of the Illinois Association of Water Pollution Control Operators.

Drew Hoelscher is the program director of drinking water operations at the Environmental Resources Training Center in Edwardsville, Illinois.