pass rate for the Class D Water Operator exam in the most recent quarter TCEQ reported. 896 people sat it. 573 went home without a license, and the $111 application fee does not come back.
A free 50-question practice exam built to work like the testing-center terminal: a clock, a question map, the formula sheet in a side panel, and no feedback until you submit. Then every answer explained, with the math worked out line by line.
The 20-hour course teaches the material. Nothing in it puts you in front of 100 questions with three hours running and a formula sheet you have to search under pressure. The first time most candidates feel that is the day it counts.
Pounds per day, detention time, pressure from tank height, hypochlorite strength. The formulas are handed to you. Knowing which line to reach for, and what to do with the units, is what the course never drilled.
0.2 mg/L free chlorine, 35 psi, 20 psi, monthly dead-end flushing, annual tank inspection. The exam asks for the Texas value, not the general idea, and the state rules are 300 pages of small print.
| This practice exam | Textbook and course | The real exam | |
|---|---|---|---|
| Timed, terminal-style sitting | Yes, 90 min for 50 questions, same pace | No | Yes |
| Formula sheet in a side panel | Yes, the same conversions | Printed in a chapter | Yes, on paper |
| Question map, flag for review | Yes | No | Yes |
| Every math problem worked out | Yes, step by step, naming the formula-sheet line | Some examples | Never |
| Score by topic | Yes, eight topics | No | Pass or fail only |
| Cost | Free | $490 to $510 | $111 plus the testing-center fee, every attempt |
Questions are original and written to TCEQ's Basic Water Works Operations curriculum. They are not copies of TCEQ exam items, which are confidential. The topic mix follows the curriculum: regulations and licensing, sources and wells, treatment, disinfection, distribution and storage, safety, water chemistry, and math.
Calculator, scratch paper, 90 minutes. Same as exam day.
Computer-based, about 100 multiple-choice questions, 3 hours. You need 70 to pass. The testing center provides a formula and conversion sheet and scratch paper; you bring a non-programmable calculator and ID. Nothing else goes in with you.
A 20-hour TCEQ-approved Basic Water Works Operations course, then a Class D application to TCEQ with the $111 fee. Once approved, you schedule at a testing center, which charges its own seat fee (around $40 to $45 at university sites).
TCEQ does not publish a percentage. Operators who have taken it describe roughly one question in eight to one in ten as a calculation, and the calculations are the ones people run out of time on. This practice exam has nine, all worked in the answer key.
For smaller groundwater systems, yes. For systems with 250 or more connections, surface water plants, and supervisory roles, TCEQ requires Class C or higher, and many Class D licenses cannot be renewed, so operators move up within a few years. The full bank includes Class C water.
Operator Exam Prep builds practice exams for state water and wastewater operator licenses. We are not affiliated with TCEQ or any state agency. Questions, corrections, or seats for a whole crew: reply to any email from us.
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