All Practice Exams

100+ Free MO Water/Wastewater Operator Practice Questions

Pass your Missouri Water and Wastewater Operator Certification Exam exam on the first try — instant access, no signup required.

✓ No registration✓ No credit card✓ No hidden fees✓ Start practicing immediately
~65-75% Pass Rate
100+ Questions
100% Free

Loading questions...

About the MO Water/Wastewater Operator Exam

The Missouri water and wastewater operator certification exam covers state-specific regulations under 10 CSR 60-14 and 10 CSR 20-9, water treatment processes, wastewater treatment operations, distribution and collection systems, laboratory testing, and safety procedures.

Questions

100 scored questions

Time Limit

2-3 hours

Passing Score

70%

Exam Fee

$45 (Missouri Department of Natural Resources (MoDNR))

MO Water/Wastewater Operator Exam Content Outline

20%

Missouri State Laws & Regulations

MoDNR certification levels, licensing requirements, 10 CSR 60-14/20-9, reporting, and compliance

25%

Water Treatment

Coagulation, flocculation, filtration, disinfection, chlorination, and treatment plant operations

25%

Wastewater Treatment

Activated sludge, sludge handling, biological treatment, nutrient removal, and process control

15%

Distribution & Collection Systems

Pump operations, hydraulics, cross-connection control, pipe maintenance, and system pressure

15%

Laboratory Testing & Math

Water quality testing, BOD, TSS, chlorine residual, calculations, and record-keeping

How to Pass the MO Water/Wastewater Operator Exam

What You Need to Know

  • Passing score: 70%
  • Exam length: 100 questions
  • Time limit: 2-3 hours
  • Exam fee: $45

Keys to Passing

  • Complete 500+ practice questions
  • Score 80%+ consistently before scheduling
  • Focus on highest-weighted sections
  • Use our AI tutor for tough concepts

Frequently Asked Questions

What certification levels does Missouri offer for water operators?

Missouri offers Levels A (highest) through D (lowest) for drinking water treatment and wastewater treatment operators, and DS-I through DS-III for distribution operators.

What score do I need to pass the Missouri operator exam?

A score of 70% or higher is required to pass all Missouri water and wastewater operator certification exams.

How much does the Missouri operator exam cost?

The exam fee is $45, which covers both the examination and certificate issuance upon qualification.