Free practice-test PDFs

Our 51 entry-level and topic practice tests are available as free, printable certification exam prep PDFs, the complete set of questions and answers with a full answer key and a plain-English explanation for every question at the back. Operators use these as water and wastewater exam questions and answers to study offline, on a break, or marked up with a pen.

Pick your exam below. Each PDF is free, just tell us where to send it. The upper-level banks run online only, interactively, randomized and explained, on their own pages, along with every test on this list.

Water Treatment practice-test PDFs

Certification levels

Water Treatment Class 1: Small Systems Operator157 questions · answer key + explanations · PDFGet the PDF →

State-specific versions

Alabama Grade II Water Operator Practice Test157 questions · answer key + explanations · PDFGet the PDF →Alaska Small Water Systems Practice Test90 questions · answer key + explanations · PDFGet the PDF →Colorado Class S & T Small Systems Practice Test111 questions · answer key + explanations · PDFGet the PDF →Idaho Very Small Drinking Water Systems Practice Test124 questions · answer key + explanations · PDFGet the PDF →Iowa Grade A Small Systems Practice Test124 questions · answer key + explanations · PDFGet the PDF →Louisiana Water Production Classes 1-2 Practice Test129 questions · answer key + explanations · PDFGet the PDF →Montana Class 4A / 4B Water Operator Practice Test103 questions · answer key + explanations · PDFGet the PDF →Texas Class D Water Operator Practice Test133 questions · answer key + explanations · PDFGet the PDF →

Practice by topic

Disinfection25 questions · answer key + explanations · PDFGet the PDF →Distribution & Storage27 questions · answer key + explanations · PDFGet the PDF →Drinking Water Regulations & Records37 questions · answer key + explanations · PDFGet the PDF →Sampling, Lab & Water Quality83 questions · answer key + explanations · PDFGet the PDF →Source Water & Wells64 questions · answer key + explanations · PDFGet the PDF →Water Treatment Maintenance & Pumps75 questions · answer key + explanations · PDFGet the PDF →Water Treatment Processes87 questions · answer key + explanations · PDFGet the PDF →Water Treatment Safety20 questions · answer key + explanations · PDFGet the PDF →

Wastewater Treatment practice-test PDFs

Certification levels

Wastewater Treatment Class 1: Entry-Level Operator119 questions · answer key + explanations · PDFGet the PDF →

State-specific versions

Alabama Grade I Wastewater Operator Practice Test131 questions · answer key + explanations · PDFGet the PDF →Alaska Wastewater Stabilization Pond (WWSP) Practice Test78 questions · answer key + explanations · PDFGet the PDF →Montana Class 1C Wastewater Operator Practice Test109 questions · answer key + explanations · PDFGet the PDF →Montana Class 3C Wastewater Operator Practice Test78 questions · answer key + explanations · PDFGet the PDF →

Practice by topic

Activated Sludge & BNR68 questions · answer key + explanations · PDFGet the PDF →Fixed Film & Lagoons17 questions · answer key + explanations · PDFGet the PDF →Preliminary Treatment & Clarification43 questions · answer key + explanations · PDFGet the PDF →Solids & Digestion45 questions · answer key + explanations · PDFGet the PDF →Wastewater Disinfection25 questions · answer key + explanations · PDFGet the PDF →Wastewater Lab & Sampling67 questions · answer key + explanations · PDFGet the PDF →Wastewater Maintenance & Pumps76 questions · answer key + explanations · PDFGet the PDF →Wastewater Regulations & Collection40 questions · answer key + explanations · PDFGet the PDF →Wastewater Treatment Safety18 questions · answer key + explanations · PDFGet the PDF →

Water Distribution practice-test PDFs

Certification levels

Water Distribution Grade 1: Entry-Level Operator140 questions · answer key + explanations · PDFGet the PDF →

State-specific versions

Alabama Grade I Distribution Operator Practice Test100 questions · answer key + explanations · PDFGet the PDF →Arkansas Very Small Water System Practice Test57 questions · answer key + explanations · PDFGet the PDF →California D1 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 →

Practice by topic

Distribution Equipment & Maintenance91 questions · answer key + explanations · PDFGet the PDF →Distribution System Components99 questions · answer key + explanations · PDFGet the PDF →Distribution Water Quality & Sampling94 questions · answer key + explanations · PDFGet the PDF →Water Distribution Math165 questions · answer key + explanations · PDFGet the PDF →Water Distribution Safety102 questions · answer key + explanations · PDFGet the PDF →

Wastewater Collection practice-test PDFs

Certification levels

Wastewater Collection Class 1: Entry-Level Operator120 questions · answer key + explanations · PDFGet the PDF →

State-specific versions

Alabama Grade I(C) Collection System Operator Practice Test100 questions · answer key + explanations · PDFGet the PDF →California Grade 1 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 →

Practice by topic

Collection System88 questions · answer key + explanations · PDFGet the PDF →Collections Equipment & Maintenance94 questions · answer key + explanations · PDFGet the PDF →Collections Monitoring & Inspection65 questions · answer key + explanations · PDFGet the PDF →Collections Safety65 questions · answer key + explanations · PDFGet the PDF →Lift Stations & Pumps58 questions · answer key + explanations · PDFGet the PDF →Wastewater Collections Math91 questions · answer key + explanations · PDFGet the PDF →