Practice tests
Free Texas Class D water and wastewater practice tests
Start practicing free right now: a diagnostic, a fresh daily set, and free calculators, plus subject drills and a full mock exam. Every question is original, reviewed, and bound to the exact Texas Class D scope. Not a generic national dump, and never a promise about your result.
Free diagnosticSee your weakest subjects in a few minutes, no account.Today's 5Five fresh, worked problems a day. Build the habit.Full mock examTimed, closed-book, 70% to pass, scored by subject.Free calculatorsTank volume, dosage, flow, each worked step by step.
Practice the water exam by subject
rules and regulationsgeneral water knowledgegroundwater sourcessurface water sourcesstorage and distributiondisinfectionoperator safetyoperator math
The full water study guidePractice the wastewater exam by subject
Statutes and RulesPermitsManagementGeneral KnowledgeSafetyLaboratoryCollectionPumpingPreliminary TreatmentPrimary TreatmentActivated SludgeTrickling FiltersPondsProcess ControlDisinfectionEffluent DisposalSludge DigestionBiosolids DisposalDesign CriteriaMath Problems
The full wastewater study guideCommon questions
- Are these real exam questions?
- No, and no honest site should claim that. Ours are original questions written to the exact Texas Class D scope and reviewed, not copied exam questions and not a generic national bank.
- Is it really free?
- The diagnostic, the daily five, and the calculators are free with no account. The full reviewed question bank and the mock exam are part of a paid plan.
- Is this for Texas Class D specifically?
- Yes. Every question is bound to one exact exam, the Texas Class D water or wastewater exam, so you study only what is actually tested.