Operations and Maintenance Flashcards

When performing confined space entry in a utility vault, what must be done FIRST?

Answer: Test the atmosphere for oxygen, flammable gases, and toxic vapors

Atmospheric testing for oxygen levels, combustible gases, and toxic contaminants is the first required step before any confined space entry.

What is the purpose of flushing water distribution mains?

Answer: Remove sediment, biofilm, and stale water to maintain water quality

Flushing distribution mains removes accumulated sediment, biofilm, and stagnant water that can degrade water quality and customer satisfaction.

Which type of pump is most commonly used to move wastewater in lift stations?

Answer: Centrifugal pump

Centrifugal pumps are the most common pump type in wastewater lift stations due to their reliability and ability to handle solids-laden liquids.

What does BOD stand for in wastewater treatment?

Answer: Biological Oxygen Demand

BOD (Biochemical Oxygen Demand) measures the amount of dissolved oxygen consumed by biological processes when decomposing organic matter in water.

A utility is experiencing frequent main breaks in a specific zone. Which approach BEST addresses the root cause?

Answer: Conduct pipe condition assessment and prioritize rehabilitation

Systematic pipe condition assessment identifies deteriorated infrastructure and guides targeted rehabilitation or replacement to reduce break frequency.

What is the primary hazard associated with hydrogen sulfide (H₂S) in sewer systems?

Answer: It is highly toxic and can cause rapid incapacitation at low concentrations

H₂S is immediately dangerous to life and health at concentrations above 100 ppm and can cause rapid loss of consciousness and death.

Which document outlines the step-by-step procedures for safely isolating equipment for maintenance?

Answer: Lockout/Tagout (LOTO) procedure

Lockout/Tagout (LOTO) procedures ensure that equipment is properly de-energized and isolated before maintenance, protecting workers from unexpected startup.