ABC Foundational Knowledge Assessment 3

Question 1

An operator notices turbidity levels in the finished water are rising. What is the most appropriate first action?

Accepted Answer

Increase coagulant dosage and monitor filter performance

Answer

Rising turbidity indicates coagulation or filtration issues; adjusting coagulant and monitoring filters is the standard corrective first step.

Question 2

Which parameter is the most direct indicator of microbial contamination risk in a treated water supply?

Accepted Answer

Total coliform presence

Answer

Total coliform bacteria are indicator organisms used to detect potential pathogen contamination in drinking water.

Question 3

In wastewater treatment, what is the main goal of the secondary treatment stage?

Accepted Answer

Remove dissolved organic matter through biological processes

Answer

Secondary treatment uses biological processes such as activated sludge to reduce dissolved and suspended organic pollutants.

Question 4

A water system operator observes a sudden drop in system pressure. Which hazard should be investigated first?

Accepted Answer

Potential backflow or cross-connection

Answer

A sudden pressure drop can allow backflow and contaminants to enter the distribution system, making cross-connection investigation the priority.

Question 5

Which disinfection byproduct (DBP) is most associated with chlorination of water containing natural organic matter?

Accepted Answer

Trihalomethanes (THMs)

Answer

Trihalomethanes form when chlorine reacts with natural organic matter in source water and are regulated under the SDWA.

(ABC) Association of Boards of Certification Practice Test