semplr.

Exams · Certifications · Licensing

Water & Wastewater Operator (WPI/ABC Class I) — Practice Exam

WC monitoring: practice questions

Our Water/Wastewater Operator bank has 9 questions on this topic. Here are 5 of them with answers; the full mock exam draws from every topic, like the real one.

Start the free mock exam

Question 1 · Wastewater Collection Class I

Why should an operator investigate a sudden drop in flow at a downstream lift station?

  1. It could mean a blockage upstream that may cause an overflow
  2. It means the system is healthy and saves power
  3. It saves power
  4. It means the system is healthy and the station is saving power
Show the answer

A. It could mean a blockage upstream that may cause an overflow — Collection system monitoring.

Question 2 · Wastewater Collection Class I

What does a 'surcharged' manhole mean?

  1. The manhole has been sealed and abandoned
  2. The pipe is new
  3. The manhole is dry and the cover is missing or broken, so debris falls in
  4. The water level is above the pipe crown, so the sewer is flowing full under pressure
Show the answer

D. The water level is above the pipe crown, so the sewer is flowing full under pressure — Signals capacity problems or blockages.

Question 3 · Wastewater Collection Class I

What does a sharp rise in sewer flow during rain usually indicate?

  1. Normal dry-weather flow from customers
  2. A pump failure
  3. Normal dry weather flow
  4. Significant inflow and infiltration
Show the answer

D. Significant inflow and infiltration — Compare wet and dry weather flows.

Question 4 · Wastewater Collection Class I

What does a gas monitor used before manhole entry check for?

  1. Oxygen, flammable gases (LEL), hydrogen sulfide and carbon monoxide
  2. Only temperature and humidity in the manhole
  3. Only pressure
  4. Only the temperature and humidity inside the manhole before entry
Show the answer

A. Oxygen, flammable gases (LEL), hydrogen sulfide and carbon monoxide — Calibrate and bump-test regularly.

Question 5 · Wastewater Collection Class I

Why should a gas detector be bump tested before use?

  1. To confirm its sensors respond to gas
  2. To clean it
  3. It isn't needed
  4. To charge the battery and clean the sensors
Show the answer

A. To confirm its sensors respond to gas — Calibrate air detectors is in the outline.

More Water/Wastewater Operator topics