Texas Wastewater A Exam Questions And Answers All Verified

Texas Wastewater A Exam Questions And Answers All Verified What is TCEQ doing to control "point source" pollution of the Texas waterways? - ANS *Permitting of domestic wastewater plants *Permitting of industrial wastewater plants Describe proper design of force main wastewater lines. - ANS Minimum two fps velocity with the smallest pump operating alone. Minimum four inch diameter pipe with 150 psi rating. What is the Standard Dimension Ratio? - ANS Ratio of outside pipe diameter (OD) to wall thickness (PVC) Describe proper design of gravity wastewater lines. - ANS Designed to flow half full ,under normal conditions, at a minimum of two fps and a maximum of ten fps. Manholes should have a minimum opening of? - ANS 24 inches and be at least 4 feet wide. pH meters should be calibrated how often? What standards should be used for calibration purposes? - ANS Daily with at least two buffers. What is the standard chlorine residual and minimum contact time on Texas wastewater permits? - ANS a. 1.0 mg/L for a minimum 20 minutes detention time at peak flow b. No chlorine residual needed if detention time is greater than 21 days As the complexity of an organization increases, what management function becomes most important? - ANS Planning What is the effective chlorine disinfecting agent? - ANS Hypochlorous Acid (HOCl) Does pH affect the chlorination process? Explain your answer. - ANS When using free chlorine the disinfectant is HOCl acid. As such it is much more effective at pH's below 7.0. Above 7.0 pH the acid begins to be neutralized. What is the effluent chlorine residual in Texas that is standard on permits and the minimum detention time? What is the maximum residual allowed? - ANS Texas standard is 1.0 mg/L for a minimum 20 minutes detention time at peak flow. Maximum residual allowed is 4.0 mg/L. A treatment plant has a clarifier that is 60 feet in diameter and is 10 feet deep. The weir is 2 feet inside the outer clarifier wall. The flow is 1.0 MGD. The weir and outflow channel is 3 feet deep. a. What is the detention time in hours? - ANS Formula