Practice quizzes that test like the real thing.
Performance-based questions across every major wastewater operator exam topic, graded instantly with full explanations so every miss becomes a lesson.
Wastewater Treatment Overview
Plant flow path, core terminology, and how each treatment stage fits together.
Preliminary & Primary Treatment
Headworks, screening, grit removal, odor control, and primary clarifier operation.
Activated Sludge: Basic Concepts
Microbiology, process control parameters, settleability, and common troubleshooting.
BNR & Nutrient Removal
Nitrification, denitrification, and biological/chemical phosphorus removal principles.
Disinfection & Chlorination
Chlorine chemistry, residual theory, dechlorination, UV, and operator safety.
Anaerobic Digestion
Two-stage digestion, temperature ranges, alkalinity, gas composition, and digester upsets.
Sludge Thickening & Dewatering
Gravity, DAF, belt, centrifuge and plate-and-frame dewatering performance and polymer use.
Laboratory Procedures
BOD, TSS, sampling, preservation, and the difference between grab and composite samples.
Pumps & Hydraulics
Centrifugal pump curves, affinity laws, head, cavitation, and pump selection.
Operator Math — Core Calculations
Temperature, area, volume, detention time, dosage, and conversions used daily in operations.
NPDES & Regulatory Compliance
Permits, monitoring reports, SSOs, and the reports that keep plants in compliance.
Safety & Confined Space
H₂S, confined space, LOTO, PPE, atmospheric monitoring, and incident-prevention basics.
Collection Systems
Inflow/infiltration, lift stations, CCTV, smoke testing, and SSO prevention.
Wastewater Microbiology
Key organism groups, indicators, and microscopic-exam clues for activated sludge health.
Trickling Filters & Fixed-Film Processes
Biofilm growth, recirculation, sloughing, filter flies, and nitrifying/roughing filter operation.
Lagoons & Natural Treatment Systems
Facultative, aerated and maturation lagoons: biology, loading, detention time, algae, and seasonal effects.
Membrane Bioreactors & Tertiary Filtration
MBR fundamentals, membrane fouling, pore sizes, MF/UF, polishing filters, and RO for reuse.
Odor Control
Sources of H₂S, wet scrubbers, carbon adsorption, biofilters, sewer chemistry, and crown corrosion.
Phosphorus Removal
EBPR, poly-P organisms, VFA demand, chemical precipitation with metal salts, and struvite recovery.
Pump Station Operations & Maintenance
Wet wells, lead/lag pump rotation, check valves, ventilation, confined-space entry, and SSO prevention.
SCADA & Instrumentation
PLCs, 4–20 mA signals, DO probe calibration, magnetic flow meters, HMIs, redundancy, and trending.
Energy Management & Aeration Efficiency
Where plant energy goes, fine-bubble diffusion, alpha factor, DO/ammonia-based control, VFD blowers, and denitrification credit.
Industrial Pretreatment Programs
Pretreatment program goals, categorical standards, SIUs, local limits, prohibited pollutants, and hauled waste.
Water Reclamation & Reuse
Title 22 foundations, treatment trains, turbidity and disinfection, RO, log reduction targets, and indirect potable reuse.
Looking for structured study notes and section explainers? Browse the Knowledge Center for cross-referenced guides.
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