semplr.

Exams · Certifications · Licensing

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

WT admin: practice questions

Our Water/Wastewater Operator bank has 8 questions on this topic. Here are 4 of them with answers; the full mock exam draws from every topic, like the real one.

Start the free mock exam

Question 1 · Water Treatment Class I

Why is maintaining positive pressure in the distribution system important?

  1. It lowers chlorine use and saves pumping energy across the whole system
  2. It lowers chlorine use and saves energy
  3. Loss of pressure can let contaminants enter through leaks and cross-connections
  4. It improves taste only
Show the answer

C. Loss of pressure can let contaminants enter through leaks and cross-connections — Pressure loss often triggers a boil-water advisory.

Question 2 · Water Treatment Class I

What is a boil-water advisory?

  1. A notice that the plant is heating water to improve disinfection in cold weather
  2. A notice telling customers to boil water before drinking because it may be unsafe
  3. A routine monthly notice
  4. A request to conserve water during a drought
Show the answer

B. A notice telling customers to boil water before drinking because it may be unsafe — Issued after pressure loss or contamination risks.

Question 3 · Water Treatment Class I

Why is plant security important?

  1. It improves taste
  2. It is only for appearance
  3. It reduces chemical costs and improves the taste of the water
  4. Unauthorized access could lead to contamination or damage
Show the answer

D. Unauthorized access could lead to contamination or damage — Security is a listed content area.

Question 4 · Water Treatment Class I

What must a water system do after a violation that poses an acute health risk, such as an E. coli MCL violation?

  1. Notify customers within a year in the annual report
  2. Give Tier 1 public notice within 24 hours
  3. Post a notice within 30 days
  4. Wait for the annual report
Show the answer

B. Give Tier 1 public notice within 24 hours — 40 CFR 141.202.

More Water/Wastewater Operator topics