Texas Wastewater Class A  Questions and Answers

Texas Wastewater Class A  Questions and AnswersSeeding of BOD samples is necessary when samples - Correct Answer - (All of the above) have a chlorineresidual, have a previously been chlorinated, have been subjected to high temperatures, containhighor low pH industrial wastes When is blue-green algae the most dominant on a pond treatment system? - Correct Answer - Summer A 30-inch diameter wastewater interceptor is observed to be flowing half-full at about two fps. Theapproximate volume of wastewater flowing through the pipe is 3.14x1.25 x 1.25 x 2 = 4.9 cfs x 449=2,200 gpm - Correct Answer - c. 2,200 gallons per minute A one-cylinder reciprocating sludge pump with a 10-inch bore and a 5-inch stroke pumps at a rateof 50cycles per minute. How many minutes must the pump be operated to pump 5,000 gallons of sludge?3.14x0.416 x 0.416 x0.416 x 50 x7.48 = 84.5 gpm 5000 gal = 59,2min 84.5 gpm b. 29 - Correct Answer - 60 minutes If an existing centrifugal pump motor is replaced with a motor with 25 percent more speed, the motor horsepower required will increase by 1.25 x 1.25 x 1.25 = 1.95 - Correct Answer - 95 percent When must TCEQ be notified about expansions of a treatment facility? - Correct Answer - Before construction In an anaerobic digester, the percentage of methane and carbon dioxide gas content should be - Correct Answer - 70% methane, 30% carbon dioxide The temperature of an anaerobic digester should be maintained at a minimum of - Correct Answer - 95° F What type of wastewater treatment operates in the endogenous bacteria growth phase? - Correct Answer - Extended air ONLYSTUDENT STORE 2025 ALL THE BEST ONLYSTUDENT STORE 2 DO NOT COPY Why is recirculation needed in a trickling filter? - Correct Answer - Keep the media wet Further reduceBOD All of the above (a, b, and c) What type of fire extinguisher would be used on an electrical control panel that has been de-energized?- Correct Answer - Class A Class C (a and d) Disinfection with chlorine is the most effective at a pH of - Correct Answer - 6.0 The biomass on a normal functioning RBC has what appearance? - Correct Answer - Grey to brownand0.05 to 0.1 inch thick The sludge from a primary clarifier should percent solids? - Correct Answer - 4% to 6% What is eutrophication in a pond system? - Correct Answer - Enrichment with nitrogen and phosphorous Causes algae blooms (b and c) How often should pH meters be calibrated? - Correct Answer - Daily In Texas, pH meters are required to be calibrated on how many buffers? - Correct Answer - two An industrial complex has a BOD discharge to the POTW of 500 pounds per day. The population equivalent of this industry is 500 lbs = 2,941 0.17 lbs BOD person - Correct Answer - 2941 The parameters of the BOD test are - Correct Answer - 5 days at 20° Centigrade Standard Dimension Ratio in pvc pipe is defined as - Correct Answer - Ratio of OD pipe diameter towall thickness How should shoring be removed from a trench? - Correct Answer - up from the bottomup In low pressure sewer systems where each tap must have a grinder pump lift station, station is considered to be - Correct Answer - part of the collection system and the responsibility of the utilityEffective communication depends on - Correct Answer - being a good listener When designing a wastewater collection system, the engineer considers the population for howmanyyears in the future? - Correct Answer - 50 According to 30 TAC Chapter 317, all pipe and fittings used in wastewater pressure shall have a minimum psi pressure rating of - Correct Answer - 150 The minimum velocity of flow in a wastewater line should be - Correct Answer - 2.0 fps At a construction job site, as the roadway speed increases, the spacing between cones and barricades should - Correct Answer - increase The major cause of wastewater line stoppages is - Correct Answer - roots and grease ONLYSTUDENT STORE 2025 ALL THE BEST ONLYSTUDENT STORE 3 DO NOT COPY Carbon monoxide (CO) poisoning symptoms are - Correct Answer - tightness in the chest nausea drowsiness and headache (all of the above) The smallest pipe size for air recirculation of a self-priming centrifugal pump is - Correct Answer - 1inchDangerous gases in a confined space may not be detected with the physical senses because - Correct Answer - some gases have no odor some gases may deaden the sense of smell some gases may displacethe oxygen (all of the above) What are the dangerous gases a collection system worker might come into contact with? - Correct Answer - CO2 CO НaS CH4 (all of the above) On a construction job site, equipment booms must maintain at least how many feet of clearance fromoverhead electric lines? - Correct Answer - 10 How should trench shoring be installed? - Correct Answer - to above the top of the trench When setting work goals for an employee, the goals should be - Correct Answer - accompanied by anaction plan According to Chapter 317, Design Criteria, a manhole can be installed within 9 feet of an existing waterline if - Correct Answer - the manhole is completely watertight and tested for no leakage As the population of a collection system increases, the ratio of peak flow to average daily flowwill - Correct Answer - decrease Motivating workers to do a bett