Wastewater Operator Exam Study Guide - Complete Solutions Updated

Wastewater Operator Exam Study Guide - Complete Solutions Updated Odors occur when treatment becomes - answer - Anaerobic What should an operator do before entering a manhole - answer - Test for all hazardous gases and oxygen levels and ventilate the manhole before entering What treatment devices is commonly used to separate and remove large solids from raw wastewater - answer - a mechanically raked bar screen What diseases are caused by pathogenic organisms that may be present in raw wastewater? - answer - Hepatitis, typhoid, paratyphoid, dysentery, and cholera What is typically used to dewater sludge? - answer - Belt press, Drying beds, solid bowl centrifuge, and gravity thickener Calculated the volume in gallons of a rectangular aeration tank that is 60 feet long, 30 feet wide and 20 feet deep - answer - 269,280 What is typically used whenever wastewater cannot flow to the treatment plant by gravity - answer - Lift station A centrifugal pump must be ? or it will not pump - answer - Primed One common type of weir design for measuring flow is - answer - V-Knotch The operator would need to increase or decrease if the ? loading on the plant is high - answer - increase/Organic A simple method for indication when to waste sludge is - answer - Total sedimentation test Landfill applied sludge must have a solids content of at least ? - answer - 20% Effluent dosage of chlorine in the contact chamber must produce a total combined residual of ? - answer - 1.0mg/L after 20 minutes TCEQ allows the reuse of wastewater, some of these uses include - answer - irrigation, aquifer recharge, cooling towers and fire protection Organic solids include - answer - organic materials from plant, animals or humans Dangerous gases are produced during bacterial decomposition of organics in wastewater. The main gases are - answer - Hydrogen sulfide, carbon dioxide and methane The majority of Dissolved Oxygen in raw sewage come from - answer - Potable drinking water Approximately How many pounds does each person contribute of BOD to the system daily - answer - 0.17 If the operator of a system received a call that a lift station is production of a strong smell of "Rotten eggs" this would be an indication that - answer - Hydrogen sulfide gas is present Sources of wastewater include - answer - Domestic, Storm water, commercial, food processing, agricultural and industrial A sewer manhole provides access into the system for cleaning or services. A manhole is typically located ? - answer - At changes in alignment, diameter, grade, direction and intersection Identify the 3 basic types of lift stations - answer - Dry, Wet and pneumatic How many feet must new manholes have an inside diameter of? Entry access must be at least how many inches? - answer - 4 feet and 30 inches What type of pump most commonly used in a lift station is - answer - Submersible In order to maintain 2 feet per second and velocity in a 6 inch main line, the fall per 100 feet of pipe will be - answer - 0.50 percent or 6 inches What is the primary cause of stoppage in a collection system - answer - grease and roots What type of gas is very toxic and deadens the sense of ? - answer - Hydrogen sulfide/smell Inflow and infiltration typically refers to - answer - Unaccounted for water in the system after heavy rains