Foundational Knowledge Assessment Flashcards

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

Answer: Increase coagulant dosage and monitor filter performance

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

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

Answer: Total coliform presence

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

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

Answer: Remove dissolved organic matter through biological processes

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

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

Answer: Potential backflow or cross-connection

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

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

Answer: Trihalomethanes (THMs)

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

Which process is used to remove dissolved gases such as hydrogen sulfide from groundwater?

Answer: Aeration

Aeration exposes water to air, allowing volatile dissolved gases like hydrogen sulfide to escape from solution.

What does the term 'MCL' stand for in the context of drinking water regulations?

Answer: Maximum Contaminant Level

MCL stands for Maximum Contaminant Level, the highest permissible concentration of a contaminant in public drinking water.