Texas · TCEQ · Class D Wastewater
Texas Class D wastewater operator exam prep
Texas Class D wastewater operator exam prep starts with the exact TCEQ scope, not a generic course. Take the free diagnostic to find your weak areas, drill them with reviewed practice, work the operator math with free calculators, and study each part of the plant to its official scope. Everything here is scoped to this one exam.
Last reviewed 2026-08-01. Facts link to their official source.
The facts that shape your prep
- Passing score
- Minimum passing score: 70 percent.
- Source: TCEQ Water System Operator Licensing ('Water Operator Licensing Overview': pass the applicable exam with a minimum score of 70 percent.)
- Time limit
- Three-hour time limit.
- Source: TCEQ Computer-Based Testing ('All exams have a 3 hour time limit unless otherwise noted'; Class A exams are the noted six-hour exception.)
- Open or closed book
- Closed book. Books and notes are prohibited; only Municipal Solid Waste Supervisor exams are open book.
- Source: TCEQ Computer-Based Testing ('Prohibited Aids During Licensing Exams' + MSW-only open-book note under 'Authorized Aids'.)
- The math on it
- Class D math: one- or two-step geometry and algebra problems involving area, volume, flow rate, and dosage rate in wastewater contexts.
- Source: TCEQ Wastewater Operator Exam Knowledge (Class D table, 'Math Problems' row.)