Water Treatment OIT Test Questions with 100% Correct Answers | Latest Version 2026/2027 | Expert Verified | Ace the Test (49pages)

Wastewater Treatment Operator Certification Test Study Guide#2 2026/2027 Study Material The following study questions were developed to assist the operator in the preparation process for taking a state licensing exam. While we feel the questions provide a broad sample of the type of questions one might expect on the state exam. TWUA and staff in no way implies, guarantees, or suggests that an operator who uses, studies, or knows the following material will pass the state exam. The following is only intended to offer an additional study tool. While TWUA and staff have proofed the questions and answers it is possible that some of the answers could be found in conflict with written materials. If you doubt or question the answer key PLEASE refer to written materials and use the answer that YOU feel best fits the question. We hope that you will find this study guide useful and we wish you the best of luck on your state exam. Wastewater Questions 1. The name of the State Agency responsible for enforcing pollution control laws in Texas is – a. Texas Water Development Board b. Texas Water Commission c. Texas Section of EPA d. Texas Commission on Environmental Quality e. Texas Water Resource and Conservation Commission 2. The term pathogenic means – a. Aerobic Bacteria b. Anaerobic Bacteria c. Fecal Matter d. Coliform Bacteria e. Capable of Causing Disease 3. The minimum separation between sewer lines and potable water lines is – a. 5 feet b. 7 feet c. 9 feet d. 11 feet e. 24 feet 4. A licensed wastewater operator is a professional who – a. Consistently does the best job possible b. Practices personal safety c. Strives to improve job knowledge d. Strives to keep the plant and collection system in the best appearance and working order e. All the above 5. An important step in testing a sample for Total Suspended Solids (TSS) is – a. Settling the sample b. Filtering the sample c. Incubating the sample d. Burning the sample e. Evaporating the sample 6. The Biochemical Oxygen Demand (BOD) of a sample is based on – a. pH readings b. Measuring Total Suspended Solids (TSS) of a sample c. Measuring the Dissolved Oxygen (DO) used d. Measuring the anaerobic decomposition e. Measuring total detention time 7. The results of a Biochemical Oxygen Demand (BOD) sample taken at a treatment plant tells the operator – a. How the plant is currently operating b. How the plant was operating 5 days ago c. How the plant was operating 10 days ago d. Is of no benefit to the operator e. How the plant will be performing at TCEQ inspection time 8. Which of the following are dangerous gases that are likely to be present in lift stations and or manholes? a. Natural gas and Gasoline fumes b. Hydrogen Sulfide and Carbon Dioxide c. Hydrogen, Sulfur, and Argon d. Oxygen, Nitrogen and Helium e. Both a & b 9. A preferred hydraulic method of cleaning sewer lines is – a. Cable & Auger b. Continuous Roding Machine c. Hydro Jet Cleaner d. Bucket & Belt Press e. Both a & d 10. Which of the following are ways to reduce bad odors coming from a collection system? a. Aeration & Air Scrubbers b. Adding Enzymes To The Collection System c. Routinely cleaning slow running or low flow lines d. Adding Chlorine or Hydrogen Peroxide to the Collection System e. Both c & d 11. Which of the following types of pipe are commonly used in a wastewater collection system? a. Vitrified Clay b. Poly Vinyl Chloride (PVC) c. Ductile Iron d. Stainless Steel e. Both a & b 12. Before entering a confined space a worker should – a. Use approved monitoring device and check for the presence of dangerous gases b. Ventilate the space with a blower c. Wear a safety harness and attach a life line