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Free practice-test PDFs

Every one of our 66 practice tests is also a free, printable PDF — the complete question bank with a full answer key and a plain-English explanation for every question at the back. Perfect for studying offline, on a break, or marking up with a pen.

Pick your exam below. Each PDF is free — just tell us where to send it. Prefer to study online? Every test also runs interactively, randomized and explained, on its own page.

Water Treatment practice-test PDFs

Certification levels

Water Treatment Class 1 — Small Systems Operator100 questions · answer key + explanations · PDFGet the PDF →Water Treatment Class 2 — Intermediate Operator100 questions · answer key + explanations · PDFGet the PDF →Water Treatment Class 3 — Advanced Operator100 questions · answer key + explanations · PDFGet the PDF →Water Treatment Class 4 — Expert / Large System Operator100 questions · answer key + explanations · PDFGet the PDF →

State-specific versions

California T1 Water Treatment Operator Practice Test100 questions · answer key + explanations · PDFGet the PDF →California T2 Water Treatment Operator Practice Test100 questions · answer key + explanations · PDFGet the PDF →California T3 Water Treatment Operator Practice Test100 questions · answer key + explanations · PDFGet the PDF →California T4 Water Treatment Operator Practice Test100 questions · answer key + explanations · PDFGet the PDF →California T5 Water Treatment Operator Practice Test100 questions · answer key + explanations · PDFGet the PDF →Small Water Systems Practice Test50 questions · answer key + explanations · PDFGet the PDF →Texas Class A Water Operator Practice Test100 questions · answer key + explanations · PDFGet the PDF →Texas Class B Groundwater Operator Practice Test100 questions · answer key + explanations · PDFGet the PDF →Texas Class B Surface Water Operator Practice Test100 questions · answer key + explanations · PDFGet the PDF →Texas Class C Groundwater Operator Practice Test100 questions · answer key + explanations · PDFGet the PDF →Texas Class C Surface Water Operator Practice Test100 questions · answer key + explanations · PDFGet the PDF →Texas Class D Water Operator Practice Test100 questions · answer key + explanations · PDFGet the PDF →

Practice by topic

Chemical Feed & Dosing50 questions · answer key + explanations · PDFGet the PDF →Coagulation & Flocculation50 questions · answer key + explanations · PDFGet the PDF →Conventional Filtration50 questions · answer key + explanations · PDFGet the PDF →Corrosion Control & Lead50 questions · answer key + explanations · PDFGet the PDF →Cross-Connection Control & Backflow50 questions · answer key + explanations · PDFGet the PDF →Disinfection50 questions · answer key + explanations · PDFGet the PDF →Distribution Systems50 questions · answer key + explanations · PDFGet the PDF →Membrane Filtration50 questions · answer key + explanations · PDFGet the PDF →Regulations & Compliance50 questions · answer key + explanations · PDFGet the PDF →Sampling & Water Quality20 questions · answer key + explanations · PDFGet the PDF →Storage & Pumping50 questions · answer key + explanations · PDFGet the PDF →Surface Water Treatment50 questions · answer key + explanations · PDFGet the PDF →Water Treatment Math50 questions · answer key + explanations · PDFGet the PDF →

Wastewater Treatment practice-test PDFs

Certification levels

Wastewater Treatment Class 1 — Entry-Level Operator100 questions · answer key + explanations · PDFGet the PDF →Wastewater Treatment Class 2 — Intermediate Operator100 questions · answer key + explanations · PDFGet the PDF →Wastewater Treatment Class 3 — Advanced Operator100 questions · answer key + explanations · PDFGet the PDF →Wastewater Treatment Class 4 — Expert / Large System Operator100 questions · answer key + explanations · PDFGet the PDF →

Practice by topic

Activated Sludge & Process Control20 questions · answer key + explanations · PDFGet the PDF →Biological Nutrient Removal20 questions · answer key + explanations · PDFGet the PDF →Fixed-Film & Lagoon Systems20 questions · answer key + explanations · PDFGet the PDF →Preliminary & Primary Treatment20 questions · answer key + explanations · PDFGet the PDF →Secondary Clarification20 questions · answer key + explanations · PDFGet the PDF →Solids Handling & Digestion20 questions · answer key + explanations · PDFGet the PDF →Wastewater Characteristics & Sampling20 questions · answer key + explanations · PDFGet the PDF →Wastewater Disinfection20 questions · answer key + explanations · PDFGet the PDF →Wastewater Operator Math20 questions · answer key + explanations · PDFGet the PDF →

Water Distribution practice-test PDFs

Certification levels

Water Distribution Grade 1 — Entry-Level Operator100 questions · answer key + explanations · PDFGet the PDF →Water Distribution Grade 2 — Intermediate Operator100 questions · answer key + explanations · PDFGet the PDF →Water Distribution Grade 3 — Advanced Operator100 questions · answer key + explanations · PDFGet the PDF →Water Distribution Grade 4 — Advanced / Large-System Operator100 questions · answer key + explanations · PDFGet the PDF →

State-specific versions

California D1 Water Distribution Practice Test100 questions · answer key + explanations · PDFGet the PDF →California D2 Water Distribution Practice Test100 questions · answer key + explanations · PDFGet the PDF →California D3 Water Distribution Practice Test100 questions · answer key + explanations · PDFGet the PDF →California D4 Water Distribution Practice Test100 questions · answer key + explanations · PDFGet the PDF →California D5 Water Distribution Practice Test100 questions · answer key + explanations · PDFGet the PDF →Texas Class A Water Distribution Practice Test100 questions · answer key + explanations · PDFGet the PDF →Texas Class B Water Distribution Practice Test100 questions · answer key + explanations · PDFGet the PDF →Texas Class C Water Distribution Practice Test100 questions · answer key + explanations · PDFGet the PDF →Texas Class D Water Distribution Practice Test100 questions · answer key + explanations · PDFGet the PDF →

Wastewater Collection practice-test PDFs

Certification levels

Wastewater Collection Class 1 — Entry-Level Operator100 questions · answer key + explanations · PDFGet the PDF →Wastewater Collection Class 2 — Operating Operator100 questions · answer key + explanations · PDFGet the PDF →Wastewater Collection Class 3 — Senior Operator100 questions · answer key + explanations · PDFGet the PDF →Wastewater Collection Class 4 — Manager / Superintendent100 questions · answer key + explanations · PDFGet the PDF →

State-specific versions

California Grade 1 Wastewater Collection Practice Test100 questions · answer key + explanations · PDFGet the PDF →California Grade 2 Wastewater Collection Practice Test100 questions · answer key + explanations · PDFGet the PDF →California Grade 3 Wastewater Collection Practice Test100 questions · answer key + explanations · PDFGet the PDF →California Grade 4 Wastewater Collection Practice Test100 questions · answer key + explanations · PDFGet the PDF →Texas Class I Wastewater Collection Practice Test100 questions · answer key + explanations · PDFGet the PDF →Texas Class II Wastewater Collection Practice Test100 questions · answer key + explanations · PDFGet the PDF →Texas Class III Wastewater Collection Practice Test100 questions · answer key + explanations · PDFGet the PDF →