Texas · TCEQ · Class D Water
Texas Class D water operator exam prep
Texas Class D water operator exam prep starts with the exact TCEQ scope, not a generic course. Take the free diagnostic to find your weak subjects, drill them with reviewed practice, work the operator math with free calculators, and study each subject to its official Need-to-Know. 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: use common conversion units from a table of equivalents; solve basic water utility problems using area, volume, and chemical dosage formulas.
- Source: TCEQ Water Operator Exam Knowledge (Class D criteria, 'Math' row (detention time first appears in the Class C criteria).)