Built for the exam, not the classroom
Readiness score
See how close you are to passing, topic by topic, and know when you're ready to schedule.
Every answer explained
Each question shows why the answer is right and the public source it comes from.
Timed mock exams
Practice under time pressure with exams weighted by topic, then review what you missed.
Weak-topic drills
Practice goes straight to the questions you missed and the topics you haven't mastered.
English y Español
Every question, answer and explanation in English and Spanish. Switch anytime.
Works offline
No account and no sign-up. Study at the job site with no signal.
Three exams today
Every question has an explanation and a cited public source. Timed mock exams match each exam's length and 70% passing score.
Class D
Water Operator
312
practice questions across 7 topics
Class D
Wastewater Operator
300
practice questions across 10 topics
BPAT
Backflow Prevention Assembly Tester
205
practice questions across 5 topics
Coming next: Water and Wastewater Class C, Customer Service Inspector, irrigation and OSSF licenses.
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Clearwell is practice material written from public sources. It does not contain official exam questions and is not affiliated with or endorsed by the Texas Commission on Environmental Quality. Always confirm requirements with current TCEQ rules.