Texas, TCEQ, Wastewater Treatment, Class D
Free Texas Class D Wastewater Math Practice
7 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, detention time, chlorine dosage, pounds formula, loading rates, 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
- Detention TimeYou practice detention time in hours and minutes, including the unit changes questions bury inside it.2 problem shapes
- Chlorine DosageYou practice dose, demand, and residual, the three-way relationship behind disinfection questions.3 problem shapes
- Pounds FormulaYou practice pounds per day from flow and dose, and running the formula backward to audit a feed.2 problem shapes
- Loading RatesYou practice hydraulic and organic pond loading: daily flow and BOD pounds spread across the surface.1 problem shapes
- Tank VolumesYou practice rectangle and round basin volumes ending in gallons, plus the circle areas loading questions need.3 problem shapes
Learn the method
Where these modules fit on the official examThe TCEQ subjects and math scope these modules serve
- 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.)
Last reviewed 2026-08-01. Facts link to their official source.