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 Permit-Required Confined Spaces and Finished Water Fluoride Calculations. This time you can test your knowledge about shoring depth, and stuffing box leakage.

Wastewater Treatment Sample Question

According to OSHA guidelines, at what depth is shoring absolutely required, when excavating a trench?

A. 2 feet
B. 4 feet
C. 5 feet
D. 10 feet

Water Treatment Sample Question

What is adjusted to control leakage from the stuffing box of a pump?

A. Mechanical seal gland
B. Mechanical seal
C. Packing gland
D. Lantern ring

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

---

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.