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Coagulation and sedimentation basins at a drinking-water treatment plant

Texas · Water Treatment · Class B

Texas Grade 3 Water Treatment Operator Exam

The Texas Grade 3 water treatment certification is designated Class B and issued by Texas Commission on Environmental Quality (TCEQ). Advanced certification for shift leads and operators at larger systems with complex processes.

Photo: U.S. EPA (public domain)

Applied math is a significant part of the Texas Class B exam.

Practicing calculations like dosage, detention time, and loading before test day is one of the most effective ways to prepare, alongside reviewing your state’s official exam content outline.

Exam facts

Exam facts
Grade levelClass B
Questions120
Time limit180 minutes
Passing score70%
DifficultyAdvanced
Exam administered byTCEQ (administered at approved testing centers)

Prerequisites for Class B

  • Grade 2 certification
  • 3–4 years of operating experience
  • Some post-secondary coursework (varies by state)

Confirm exact requirements with Texas Commission on Environmental Quality (TCEQ).

What's on the exam

  • Coagulation and flocculation
  • Sedimentation and clarification
  • Filtration (conventional, direct, membrane)
  • Disinfection and disinfection byproducts
  • Corrosion control and stabilization
  • Source water and watershed protection
  • Advanced process optimization
  • Regulatory compliance strategy

The math on the Water Treatment exam

These calculations are commonly included in water treatment operator exam preparation and may appear on your exam depending on your certification level and state. Practicing them is one of the most effective ways to prepare.

  • Chemical dosage (mg/L to lbs/day)
  • Chlorine demand and CT calculations
  • Detention time
  • Filter loading and backwash rate
  • Flow rate and velocity
  • Percent strength of solutions

Free Class B practice questions

Sample questions with full explanations at this level.

Take the practice quiz →

Frequently asked questions

What is the Texas Grade 3 water treatment certification called?
In Texas, the Grade 3 water treatment certification is designated Class B, issued by Texas Commission on Environmental Quality (TCEQ).
How many questions are on the exam and what score do I need?
The exam has about 120 questions with a 180-minute time limit, and you need 70% to pass. It is administered by TCEQ (administered at approved testing centers).
What are the prerequisites for Class B in Texas?
Typical prerequisites: Grade 2 certification; 3–4 years of operating experience; Some post-secondary coursework (varies by state). Exact requirements are set by Texas Commission on Environmental Quality (TCEQ).