TEXAS Wastewater Class A Exam - Complete Solutions (Answered) The parameters of the BOD test are 5 days at 20° Centigrade An Imhoff tank is what type o... [Show More] f treatment process? Primary Standard Dimension Ratio in pve pipe is defined as Ratio of OD pipe diameter to wall thickness MSDS sheets must be kept for how many years after you have stopped using the chemical? 30 A pneumatic ejector is a lift station pumping device How should shoring be removed from a trench? from the bottom up The most common pump used in the collection system is Centrifugal In low pressure sewer systems where each tap must have a grinder pump lift station, the lift station is considered to be Part of the collection system and the responsibility of the utility Effective communication depends on being a good listener A construction site safety evaluation checklist must include a. placement of equipment, vehicles, and spoil bank b. placement of flaggers, barricades, cones and other safety equipment c. use of warning signs When designing a wastewater collection system, the engineer considers the population for how many years in the future? 50 According to 30 TAC Chapter 317, all pipe and fittings used in wastewater pressure mains shall have a minimum psi pressure rating of 150 The minimum velocity of flow in a wastewater line should be
2.0 fps At a construction job site, as the roadway speed increases, the spacing barricades should Increase A piston pump with a 5-inch piston and a 10-inch stroke strokes 60 times a minute. How many minutes will operated to pump 6,000 gallons? 5x5x0.0408x0.833x60 = 51 gpm 6,000 gal/51 gpm=117.6 round to 118 A bubbler level control system works off of what principal? differential pressure The major cause of wastewater line stoppages is roots and grease What type of valve is usually used for isolation? Gate Carbon monoxide (CO) poisoning symptoms are all of the above a. tightness in the chest b. nausea c. drowsiness and headache Fresh wastewater is desirable because it is much easier to treat. The physical characteristics of fresh wastewater are dishwater gray in color The smallest pipe size for air recirculation of a self-priming centrifugal pump is 1 inch Dangerous gases in a confined space may not be detected with the physical senses because a. some gases have no odor b. some gases may deaden the sense of smell c. some gases may displace the oxygen What are the dangerous gases a collection system worker might come into contact with? all of the above a. CO2 b. CO c. H,S d. CH When designing a wastewater rehab program, the first step is to define the objectives of the program The goal of a sanitary wastewater physical survey is to Identifying problems in the system need a rehab When should drop manholes be utilized? wastewater velocities greater than ten fps flows entering the manhole 24 inches or greater above the floor Sewer balls or pigs are what type of wastewater cleaning equipment? mechanical cleaning equipment On a construction job site, equipment booms must maintain at least how many feet clearance from overhead electric lines? 10 How should trench shoring be installed? Two above the top of the trench If an existing centrifugal pump motor is replaced with a motor with 20 percent more speed, the motor horsepower required will increase by 1.2x1.2x1.2=1.728 73 percent When setting work goals for an employee, the goals should be accompanied by an action plan According to Chapter 317, Design Criteria, a manhole can be installed within 9 feet of an existing waterline if 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 flow will Decrease One of the most important factors affecting the slope of a gravity wastewater line is pipe bedding A wastewater pipe has a slope of 4 feet in 200 feet, it is referred to as c. 0.02 feet per foot d. two percent When laying bell and spigot wastewater trench bedding should be scooped out at joints > support pipe on the barrel the bell end should be pointed upstream Motivating workers to do a better job is best done by letting workers participate in setting goals One important element of a good communicator is Good listener [Show Less]
