Texas, TCEQ, Wastewater Treatment, Class D
Free Texas Class D Wastewater Math Practice
Last reviewed 2026-08-01. Facts link to their official source.
4 free practice modules cover the Class D math on the Texas Class D wastewater operator exam that TCEQ confirms at this grade: unit conversions, flow and volume, chlorine dosage, and tank volumes. Every problem uses fresh numbers, shows all ten worked steps, and saves your progress on this device.
Pick a module
- Unit ConversionsYou practice gallons to cubic feet, MGD to gpm, psi to feet of head, and percent to mg/L.4 problem shapes
- Flow and VolumeYou practice the flow triangle: volume, flow rate, and time, solved for whichever one the question hides.3 problem shapes
- Chlorine DosageYou practice dose, demand, and residual, the three-way relationship behind disinfection questions.3 problem shapes
- Tank VolumesYou practice rectangle and round basin volumes ending in gallons, plus the circle areas loading questions need.3 problem shapes
Where these modules fit in the official exam
- The official subject list this module serves
- Twenty official Need-to-Know subject categories, from Statutes and Rules through Math Problems (incl. Permits, Design Criteria, Safety, Laboratory, Collection, Pumping, treatment stages, Process Control, Disinfection, Sludge Digestion, Biosolids, Effluent Disposal).
- Source: TCEQ Wastewater Operator Exam Knowledge ('What You Need to Know for a Class D Wastewater Treatment Plant Operator Exam' table.)
- The official math scope
- 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.)