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Level 3 · Advanced sample questions

Safety Practice Questions for Level 3 · Advanced

5 free sample questions on safety for the Level 3 · Advanced wastewater treatment operator exam. Try each one, then open the answer to check your work.

  1. Question 1

    A pump is locked out, its suction line is blanked, and its casing is safely drained to zero pressure. When the drain is closed, pressure returns each time another pump starts on the common discharge header. Casing temperature stays steady. Which source must the isolation plan address?

    1. Thermal expansion of water trapped in the casing
    2. Gravity pressure entering through the suction line
    3. Pressure left from the pump's last operating cycle
    4. Header pressure passing through the discharge isolation
    Show the answer

    Answer: D. Header pressure passing through the discharge isolation

  2. Question 2

    During a permitted entry, a nearby chemical transfer releases chlorine toward the space's ventilation intake. The entrants' four-gas meter has no chlorine sensor and shows normal readings. Which action has priority?

    1. Arrange chlorine testing at the ventilation intake
    2. Have the transfer crew isolate the chemical source
    3. Order the entrants out and suspend the entry
    4. Move the intake upwind
    Show the answer

    Answer: C. Order the entrants out and suspend the entry

  3. Question 3

    A storage review finds that sodium hypochlorite and acid tanks have separate, correctly sized containment areas. However, both containment drains lead to one common sump. Which proposed change addresses the remaining chemical-mixing hazard?

    1. Increase common-sump pumping to shorten chemical contact time
    2. Use independent collection systems with no common connection
    3. Raise both containment walls to add spill storage volume
    4. Add a high-level alarm and automatic sump shutdown
    Show the answer

    Answer: B. Use independent collection systems with no common connection

  4. Question 4

    A platform task requires reaching an unguarded edge. The proposed fall-arrest system needs 18 feet of clearance, but only 12 feet is available. The existing restraint system cannot reach the work point. A portable guardrail system approved for the platform is available. Which plan should be used?

    1. Use fall arrest with a shorter lanyard and extra rescue worker
    2. Lengthen the restraint line and assign a safety monitor
    3. Install the approved guardrail before starting work
    4. Use a warning line with a dedicated spotter
    Show the answer

    Answer: C. Install the approved guardrail before starting work

  5. Question 5

    A supervisor reviews weekly eyewash records and finds that weak flow was documented three times. The unit remained marked available, corrosive work continued, and an open repair ticket was never verified closed. Which procedure change best corrects the program gap?

    1. Shorten the interval between activation checks and add a second weekly check
    2. Require an operable alternate eyewash or stop corrosive work
    3. Review open eyewash repair tickets during the next scheduled annual inspection
    4. Record the measured flow while leaving the unit available
    Show the answer

    Answer: B. Require an operable alternate eyewash or stop corrosive work

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