TEXAS WASTEWATER CLASS A EXAM 2024-2025, Exams of Nursing

Download TEXAS WASTEWATER CLASS A EXAM 2024-2025 and more Exams Nursing in PDF only on Docsity! 1 | P a g e TEXAS WASTEWATER CLASS A EXAM 2024-2025 WITH ACTUAL CORRECT QUESTIONS AND VERIFIED DETAILED ANSWERS |FREQUENTLY TESTED QUESTIONS AND SOLUTIONS |ALREADY GRADED A+|NEWEST|GUARANTEED PASS |LATEST UPDATE 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 67. The major cause of wastewater line stoppages is 2 | P a g e roots and grease What type of valve is usually used for isolation? gate Carbon monoxide (CO) poisoning symptoms are a. tightness in the chest b. nausea c. drowsiness and headache d. all of the above 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 b. 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? a. CO2 b. CO c. H,S d. CH, e. all of the above When designing a wastewater rehab program, the first step is to d. 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? a. 10 How should trench shoring be installed? Two above the top of the trench 5 | P a g e Manholes in place $1,500.00 each Wastewater connections $250.00 each 3000 x 85 = 255,000 15 x1500 = 22,500 50x 250 = 12,500 255,000 + 22,500+ 12,500 = $290,000 2000 x 85 = 170,000 12x1500 - 18,000 30x250 =7,500 170,000 + 18,000 + 7,500 = S195,500 195,000/290000 =0.67 = 67% If the float that turns on the lead pump in a wastewater lift station is situated above a gravity influent line, the line will tend to have a grease problem If an operations company ceases its operation or is sold such that control of the company is transferred to another party, the company's operations certificate is revoked In 2.5 minutes, a lift station will fill up 18" with no pumps running. In 3.25 minutes, both pumps will drop the level in the lift station 18". In 7 minutes, the large pump will drop the level 18". What is the capacity of the small pump? The lift station is 10' x 10 x 10'. 10x10x1.5x7.48=1122 1122 gal/2.5=449 gpm inflow Both 1122/3.25=345 gpm + 449 gpm = 794 gpm both Large 1122/7=160 gpm + 449 gpm = 609 gpm large Small 794 gpm - 609 gpm = 185 gpm 185 gpm H,SO, is a(n). chemical compound What is the velocity of water flowing through a clarifier that is 16 feet deep x 45 feet wide 135 feet long if the flow is 5,837 gpm? Q- AxV 13=720x fps 0.02 fps 6 | P a g e A chemical element is a atom Chemical dechlorination can be accomplished with? a. sodium Bisulfite b. sulfur Dioxide A crucible and filter weigh 21.6870 grams. After filtering 50 ml of sample through the filter, and then drying, desiccating and weighing them, the crucible, filter, and sample weigh 21.7250 grams. How many mg/L of suspended solids are in the sample? b. 760 Three hundred milliliters of 0.02 N H,SO, is needed for a lab test. The lab stocks a standard of 0.5 N. How many ml of the 0.5 N will be needed? 300 x0.02 = V x0.5 300x0.02 0.5 12 How would an operator increase the degree nitrification in an activated sludge plant? increase D0 and increase sludge age What processes are used to check an upset activated sludge plant? BOD loadings, F/M ratio, SV 30, MCRT, DO When chlorine used, the effective disinfectant is HOCI Aerobic digestion is a(n) process. endogenous Distilled water used for the BOD analysis should not exceed mg/L oxygen depletion. 0.2 Chlorine disinfects the best at low pH The inside diameter of a manhole must be at least wide. 48 inches What does biomonitoring test for? effluent toxicity Why is recirculation needed in a trickling filter plant? a. to keep the zoogleal mass wet during low flow periods b. to assist in flooding the filters and to increase sloughing 7 | P a g e The sludge from a primary clarifier should contain what percent solids? 4% to 6% The Federal Clean Water Act: a, requires a permit for disposal of sludge b. requires a permit for ocean discharges of wastewater c. requires a permit for disposal of dredge material d. creates a national permit system for all wastewater The effectiveness of an activated sludge process depends on? amount of activated solids in the system type and health of organisms in the solids acration basin detention time influent characteristics A predominance of filaments in an activated sludge plant indicates what? low DO poor settling nutrient imbalance What is dissolved air floatation in a wastewater plant usually used for? grease removal What are the hazards of using powered activated carbon? a. fire/explosive b. inhalation c. uncomfortable working conditions Why is lime added to sludge? to raise the pH and assist in pathogen reduction How often must a facility conduct a TCLP on its sludge if its sludge disposal is equal to or greater than 15,000 metric tons annually? monthly If effluent is land applied for irrigation what tests must be run? CBOD and TSS pH and dissolved solids total nitrogen total phosphorous A cyclone grit separator operates on what principle? centrifugal force Which temperature is more important to the operation of a trickling filter? influent temperature What is the MCL for coliform? per b. 1.0 per 100 mls Assume that a 12% solution of a substance weighs 10.6 lbs/gal.and a 0.8% solution of the same substance weighs 8.76 lbs/gal. If 10.0 gallons of the 12% solution are mixed with 50 gallons of the 0.8% solution, the percent strength of the mixed solution would be 10 | P a g e (All of the above) have a chlorine residual, have a previously been chlorinated, have been subjected to high temperatures, contain high or low pH industrial wastes When is blue-green algae the most dominant on a pond treatment system? Summer A 30-inch diameter wastewater interceptor is observed to be flowing half-full at about two fps. The approximate volume of wastewater flowing through the pipe is 3.14x1.25 x 1.25 x 2 = 4.9 cfs x 449 = 2,200 gpm 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 rate of 50 cycles 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 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 95 percent When must TCEQ be notified about expansions of a treatment facility? Before construction In an anaerobic digester, the percentage of methane and carbon dioxide gas content should be 70% methane, 30% carbon dioxide The temperature of an anaerobic digester should be maintained at a minimum of 95° F What type of wastewater treatment operates in the endogenous bacteria growth phase? Extended air Why is recirculation needed in a trickling filter? Keep the media wet Further reduce BOD 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? Class A Class C (a and d) Disinfection with chlorine is the most effective at a pH of 6.0 The biomass on a normal functioning RBC has what appearance? Grey to brown and 0.05 to 0.1 inch thick 11 | P a g e The sludge from a primary clarifier should percent solids? 4% to 6% What is eutrophication in a pond system? Enrichment with nitrogen and phosphorous Causes algae blooms (b and c) How often should pH meters be calibrated? Daily In Texas, pH meters are required to be calibrated on how many buffers? 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 2941 The parameters of the BOD test are 5 days at 20° Centigrade Standard Dimension Ratio in pvc pipe is defined as Ratio of OD pipe diameter to wall thickness How should shoring be removed from a trench? up from the bottom up In low pressure sewer systems where each tap must have a grinder pump lift station, station is considered to be part of the collection system and the responsibility of the utility Effective communication depends on being a good listener 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 shall have a minimum psi pressure rating of 150 The minimum velocity of flow in a wastewater line should be 2.0 fps 12 | P a g e At a construction job site, as the roadway speed increases, the spacing between cones and barricades should increase The major cause of wastewater line stoppages is roots and grease Carbon monoxide (CO) poisoning symptoms are 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 1 inch Dangerous gases in a confined space may not be detected with the physical senses because some gases have no odor some gases may deaden the sense of smell some gases may displace the oxygen (all of the above) What are the dangerous gases a collection system worker might come into contact with? CO2 CO НaS CH4 (all of the above) On a construction job site, equipment booms must maintain at least how many feet of clearance from overhead electric lines? 10 How should trench shoring be installed? to above the top of the trench 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 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 being a good listener 15 | P a g e problem is Testing of mixed liquor indicates the MLSS is 2500 mg/L and the settling test shows that a 1000 ml sample settles to 400 mls after 30 minutes. What is the SVI? 400 x 1000 2500 160 160 In the problem above, what the sludge quality? Bulking Which activated sludge process has 18 to 20 + hours detention time in the aeration basin? Extended air What is the minimum clearance from the sidewall of a pipe to the trench wall in an excavation? 4 inches What is the definition of pH? The logarithm of the reciprocal of the hydrogen ion concentration The negative logarithm of the hydrogen ion concentration How often should pH meters be calibrated? Daily trench is 4,100 feet long, four 4 wide and 6 feet deep. There is a 12-inch diameter pipe in the bottom of the trench. How many cubic yards of material were removed from the trench? 4x6x4,100 3,644 27 3,644 In the problem above, how many cubic yards of material will be required to fill the trench? 3.14x0.5 x0.5 x 4,100 =119cu yds 27 3,644 -119 = 3,525 3,525 What is the standard chlorine residual and contact time on Texas discharge permits? e. None of the above organization increases, As the complexity of an organization increases, what management function becomes most important? Planning The following scenario is to be used in answering questions 38, 39, and 40. A pump with a 15-inch impeller is running at 1170 RPM s, with pump efficiency of 75%, and is pumping 500 gpm with 75 feet of head. If the RPM of the pump is increased to 1750 RPMS calculate the following: New output in gpm: 1750 1770 =F = 1.5 500 x 1.5 = 750 gpm 750 New head in feet: 75 x 1.5 x 1.5 = 168.75 170 New horsepower required: 16 | P a g e 750 x 170 - 43 3960 x 0.75 a. 43 What compound or compounds are formed when Cl, combines with water? Both a and d When chlorinating treated wastewater, what chlorine residual do we test for? Chloramine and Total What is the standard pH range on Texas effluent discharge permits? b. 6.0 to 9.0 A wastewater treatment plant has a clarifier that is 80 feet in diameter and is 12 feet deep. The flow is 2.5 mgd. The single weir is two feet inside the outer wall and is 3 feet deep. What is the clarifier detention time in hours? What is the clarifier detention time in hours? 2,500,000 gpd - 104,167 gph 24 hrs/day 3.14 x 40 x 40 x 9 x 7.48 gal 3.14 x 36 x 36 x 3 x 7.48 = 91,318 338,216 + 91,318 429,534 gallons 429,534 gals = 4.1 hrs 104,167 gph 4.1 What is the hydraulic loading on the clarifier in gal/sq ft/day? 3.14 x 38 x 38 = 4,534 sq ft 2,500,000 gpd = 551 gal / sq ft I day 4,534 sq ft 551 What is the weir loading in gal/linear ft/day? 3.14 x 76 = 239 ft of weir 2,500,000 gpd = 10,460 gal / lin ft / day 239 ft weir 10,460 In Texas, an oxidation ditch treatment plant is referred to as Racetrack In Texas, pH meters are required to be calibrated on how many buffers? two An industrial complex has a BOD discharge to the POTW of 500 pounds per population equivalent of this industry is 500 lbs - 2,941 0.17 lbs BOD/ person 2941 What substance will interfere with a DPD chlorine test? Manganese The parameters of the BOD test are 5 days at 20° Centigrade An Imhoff tank is what type of treatment process? Primary 17 | P a g e 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? c. 30 A pneumatic ejector is a. a lift station pumping device How should shoring be removed from a trench? d. from the bottom up 57. The most common pump used in the collection system is d. 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 The name of the State Agency responsible for enforcing pollution control laws in Texas Texas Commission of Environmental Quality The term pathogenic means Capable of causing disease The minimum separation between sewer lines and potable water lines is 9 feet A licensed wastewater operator is a professional consistently does best job possible, practices personal safety, strives to improve job knowledge, strives to keep the plant and collection system in the best appearance and working order An important step in testing a sample for Total Suspended Solids is 20 | P a g e The Texas Commission on Environmental Quality can revoke an operator's license if the operator causes permit violation, falsifies records or neglects their duty If accidental discharge, bypass, or spill (SSO) of wastewater occurs the responsible party MUST notify TCEQ regional offices within ____ hours 24 Aerobic Bacteria require _____ in the water for their metabolism oxygen Anaerobic Bacteria _____ live with O2 present in the water for their metabolism cannot Facultative Bacteria require__________in the water for their metabolism either aerobic or anaerobic conditions Chemical characteristics of sewage include solids, greases, dissolved oxygen, O2 Demand, pH, and gasses _________removes Total Suspended Solids (TSS) filtration Inorganic solids include sand, grit and minerals Organic solids include organic materials from plants, animals or humans A good plant influent pH is about 7.2 Dangerous gases are produced during bacterial decomposition of organics in wastewater. The main gasses are Hydrogen sulfide, carbon dioxide and methane The majority of Dissolved Oxygen in raw sewage comes from Potable Drinking Water Each person contributes approximately ______ lbs of BOD to the system daily. 0.17 Sources of waste water include 21 | P a g e domestic, storm water, commercial, food processing, agricultural and industrial A sewer manhole provides access into the system for cleaning or service. A manhole is located at changes in alignment, diameter, grade, direction and intersection New manholes must have an inside diameter of at least ______ feet and the entry access must be at least ____inches. 4 feet and 24 inches In the past ____ was used to construct manholes. This product is prohibited for construction or grading today brick and mortar Vitrified clay and Poly Vinyl Chloride (PVC) are the most common pipe materials used for sewer lines but other materials are available such as Ductile iron, Cast iron, Acrylonitrile butadiene styrene (ABS), Concrete, Polyethylene, & Asbestos concrete Whenever wastewater cannot flow to the treatment plant by _____, a _____ is typically used. gravity/ lift station The primary cause of stoppage in a collection system is _____ and _____ grease/roots The _____pump is most commonly used in a lift station centrifugal A centrifugal pump must be ____ or it will not pump primed ______ gas is very toxic and deadens the sense of ______ Hydrogen Sulifide/smell ______ gas is colorless, odorless and heavier than air Methane ______ are the smallest , most numerous, and most important of the activated sludge microorganisms bacteria Organic loading refers to the pounds per day of ____ per acre feet or 1,000 cubic feet of filter media 22 | P a g e BOD Hydraulic loading refers to the volume of ____, including recirculation, applied to the filter water The most common type(s) of trickling filters are- Standard rate (1-4 mgd) and High Rate (10-40 mgd) Odors occur when treatment becomes anaerobic ____________gas is greenish-yellow, pungent, heaver than air and highly toxic chlorine One common type of weir design for measuring flow is V-Knotch Inflow and Infiltration (I&I) typically refers to unaccounted for water in the system after heavy rains If the ____ loading on the plant is high, the operator would need to ____Dissolved Oxygen (DO) levels. Organic/Increase A simple method for indicating when to waste sludge is 30 minute settling test Organic loading of a stabilization pond is about ____ pounds of BOD/acre/day with a detention time of at least ___ days. 35 BOD/ 30 Days Anaerobic digesters are covered to keep out ____, and to trap useful methane which can be used to keep the digester warm. free oxygen Unstable anareobic sludge contains streaks of _________ or ________. gray/green Aerobic digestion is an ____process whereby the aerobic bacteria consume themselves Endogenous Approved disposal methods for digested, dewatered, sludge's are landfill, ____ and ____. 25 | P a g e The minimum size for a gravity flow sewer line on city right-of-way and the minimum grade is 6 inch and a grade of 0.50 percent The most accurate way to find the average wastewater flow rate in an existing 10-inch sewer main is Obtaining actual flow data & verifying with field data What is the greatest advantage for using fiberglass manholes in areas with high groundwater? fiberglass is not subject to infiltration A __________ pump would most likely be used when discharging into a 10" diameter pressure sewer main. Centrifugal Excessive power consumption by a pump could be caused by Worn bearings and worn impeller Trench safety is a great concern in Texas. OSHA requires that anytime an excavation is greater than __ feet deep it must be protected by ______. 5 feet / An approved Trench Box, Shoring, or Sloping In an excavation if a ladder is used as a means of exit, it must extend ________feet above the ground and be secured and within ____ feet laterally of anyone in the excavation. 3 feet / 25 feet laterally A ____________ would be the best to determine if a storm drain is connected to a sanitary sewer line. Smoke Test _________ would most commonly be used to seal a number of joint leaks on a main with minimal interruption internal grouting Pre-treatment of wastewater would include: Coarse or fine screening, grinding and grit removal and grease removal and pre-aeration Primary treatment of wastewater would include 26 | P a g e settling tanks or basins, scum collection and removal, sludge collection and removal Secondary treatment typically used today would include Stabilization ponds, trickling filters, rotating biological contractors (RBC) & activated sludge Essential components of the wastewater collection system include Sewer mains & piping, Lift Stations, Pumps, Grease & Sand traps, & Manholes Grit removal would be considered A part of Primary Treatment The protozoa that causes dysentery would most likely be destroyed by Disinfection Using final plant effluent in cooling towers would be a Beneficial way to reuse treated effluent TCEQ may authorize discharge of untreated wastewater into or near a receiving stream in extreme cases. This is referred to as Bypass Enforcement action from TCEQ may be taken if pollution or waste violates the Texas Water Code. Violations of Water Code may include Unauthorized discharge, accidental discharge & health hazard Solids in wastewater are classified as Total: solids or residual (TR), Suspended (TSS), Dissolved (TDS), Settleable (SS), Non-setteable, Floatable, Organic and Inorganic Total Suspended Solids (TSS) are those that Can be filtered out Total Dissolved Solids (TDS) are those that 27 | P a g e cannot be filtered out Settable Solids (SS) are those that Settle out when left standing for extended periods of time Non-settleable Solids are Small particles that do not settle Volatile Solids (VSS) are those that Are determined by burning the residue from the Total Solids determination Inorganic Solids (ash) are those that Consist of sand, grit, & minerals and can be suspended or dissolved Organic matter in wastewater can be ______or________and makes up approximately _______% of the total solids Dissolved or Suspended / 65 The typical pH of an influent entering the plant will vary from 6.5 to 8.0 Acute toxicity occurs when There is a rapid die off of treatment organisms Chronic toxicity occurs when Certain microorganisms become inactivated but others continue to work resulting in a sick biological process A mechanical device that screens & cuts large solids in small particles Comminutors Detention time in wastewater typically refers to The time sewage is kept in a sedimentation basis There are five (5) major components to a trickling filter Filter floor, underdrain, walls, filter media, & distributer arms Zoogleal Mass refers to 30 | P a g e In the activated sludge process, the _______ is called the heart of the activated sludge process. Clarifier In the activated sludge process, factors that will influence the operation of the final clarifier are Loading, solids applied, settling, thickness of solids, rate of return & Wasting In the activated sludge process, the clarifier will concentrate return sludge and waste sludge about ___ to__ times the solids concentration of the mixed liquor two (2) to four (4) In the activated sludge process, for the classifier to do its job, the ____ must be retained long enough to allow ______ to settle and liquid to rise. water/ solids In the activated sludge process, as more mixed liquor flows to the classifier, the thickness of the sludge blanket will Increase as solids accumulate In the activated sludge process, biological solids from the bottom of the clarifier must be returned to the aeration basin for re-seed. This process is accomplished by Air lift pumps, centrifugal pumps, Diaphragm pumps, Screw pumps & Gravity Flow In the activated sludge process, no sludge process will work properly without Regular removal of excess solids In the activated sludge process, Mass Balance refers to Maintaining the balance between Return Sludge Flow, Return Sludge, Aeration tank volume, Mixed liquor suspended solids In the activated sludge process, the terms F/M ratio is important because this refers to Food to Microorganism Ratio In the activated sludge process, the F/M Ratio is calculated by ______ the pounds of _________ by the pounds of MLVSS in the ___________. Dividing/ Incoming BOD/ aeration tank In the activated sludge process, the term Gould Sludge Age refers to 31 | P a g e How long in days a pound of solids stays in the aerator In the activated sludge process, Gould Sludge Age (GSA) is calculated by Dividing the total pounds of TSS in the aerator by the pounds of TSS entering the aerator as raw In the activated sludge process, the term Mean Cell Residence Time (MCRT) refers to The amount of time the living cells are kept in the plant In the activated sludge process, daily observation of the aeration basin treatment processes are essential. The operator should pay close attention to Surface turbulence, Foam, Odors, & Color In the activated sludge process, daily observation of the final clarifier is also essential. The operator should pay close attention to Surface scum, Sludge blanket, Weir Flow, Rising solids, & Clarifier overflow In the activated sludge process, five (5) Important control parameters are Dissolved Oxygen level, Aerator solids level, Solids quality, Rate of returned sludge, & Wasting rate In the activated sludge process, Dissolved Oxygen levels throughout the aeration basins are measured using a portable DO meter. The operator should keep DO levels between ______ and _______. 2 mg/L and 4.0 mg/L In the activated sludge process, "Classic Bulking" is a common problem typically caused by Low density sludge In the activated sludge process, Sludge Rising differs from "Sludge Bulking" and "Sludge Rising" is typically associated Nitrification - De-nitrification process In the activated sludge process, techniques used to reduce "Frothing & Foaming" typically include Adjusting sludge age, Reducing the amount of air, Spraying the frothing area with water, Applying de- foaming agents In the activated sludge process, floc is very important to the settling process. Floc is composed primarily of Bacteria, Protozoa, Microscopic Animals, & Fungi In the activated sludge plants, the operator will experience problems. Some of the common Treatment plant problems include 32 | P a g e Insufficent capacity, Equipment failures, Design inadequacies, Poor maintenance, & Inflow rates exceed plant capacities. In the activated sludge plants the operator will experience problems. Some of the common Influent problems include Septic inflow, Organic overloading, and under loading, Hydraulic overloading, Solids washout during storm inflow, Toxic substances, Shock loads, & Nutrient deficiencies In the activated sludge plants, the operator will experience problems. Some common Operational problems include Sludge quality, foaming, improper operating techniques In the activated sludge plants, the operator will experience problems. Some common Environmental problems include. Low temperatures, System pH out of range, & Excessive algae growth In the activated sludge plants, to properly set the clarifier return rate the operator must know three things Return activated sludge rate, Sludge blanket thickness, & the Solids concentration of the return flow The typical sludge age for extended aeration plants is 20 to 40 days In the activated sludge plant, good quality sludge will settle _________& _______ over _________ minute period. Gently & Uniformly over 15 to 20 minutes In the activated sludge plant, old sludge quality will settle ________& _________ over ________ minute period. Rapidly and ragged over 5 minutes. In the activated sludge plant, there are (5) important nitroen transformation processes that occur by microorganisms. They are- Assumilation, Ammonification, Nitrification, Denitrification, & Nitrogen fixation. __________in the effluent from an activated sludge process is a pollutant and may create toxic conditions for aquatic life in the receiving stream Nitrogen Denitrification occurs in an activated sludge system when there is __________ to maintain the aerobic metabolism of the carbon stabilizing bacteria. Insufficient Dissolved Oxygen The lack of _________ triggers the facuitative bacteria to change from aerobic and anaerobic 35 | P a g e Drum speed Information on preventive maintenance procedures, materials, and frequencies for plant structures should be taken from? Manufactures literature What is the minimum surface loading rate on a trickling filter? 1 MG/Acre/Day Standard Rate Filter What type of process requires scum from the final clarifier to be place in the digester? Trickling filter and Rotating Biological Contactor (RBC) What is the assumed BOD removal rate used in plant design calculations for primary clarifiers? 35% What is the name of the algae that is abundant in stabilization ponds? Phytoplankton What regulates the RPM's on an air driven Rotating Biological Contactor (RBC)? Air buoyancy On a water lubricated pump, what should the seal water pressure be? 5 psi over stuffing box pressure Increasing the return rate of a conventional activated sludge plant has what effect on process control? Decrease detention time in aeration basin, raise dissolved oxygen, lower sludge blanket. If an employee is guilty of misconduct as defined by the utilities personnel policies the supervisor should? Attempt to modify the employee's behavior through training and other forms of assistance and inform the employee of the consequences. In a stability pond, what is density stratification? 36 | P a g e Warm water being lighter the cool water remains near the surface, thus producing a layered effect. What clarifiers have maximum surface loading at peak and design flow? Primary and intermediate What gives pistons longer wear? Longer stokes and slower RPM's. What do you use to run a 30 minute settling test? 1000 ml graduated cylinder. Which process is more like an oxidation pond? Extended aeration Carbon dioxide does not harm mucous membranes or your lungs? True What meter measures resistance? Ohm meter What are the limits of authority for a line manager position? Supervises their subordinates only What is the "Span of Supervision?" The number of subordinates that you supervise. How often should maintenance be scheduled? Daily When a centrifugal blower is operating what happens to the oil level? It drops Excessive "Hum" in a motor indicates what? Single Phase Seeding of BOD samples is necessary when samples _______. to be tested contains materials not readily biodegradable, or if it contains toxic materials such as phenol, formaldehyde or similar microbic. A one-cylinder reciprocating sludge pump with a 10-inch bore and a 5-inch stroke pumps at a rate of 50 cycles per minute. How many minutes must the pump be operated to pump 5,000 gallons of sludge? 37 | P a g e If an existing centrifugal pump motor is replaced with a motor with 25 percent more speed, the motor horsepower required will increase by ________. When is blue-green algae the most dominant on a pond treatment system? When must TCEQ be notified about expansions of a treatment facility? The temperature of an anaerobic digester should be maintained at a minimum of ________. What type of fire extinguisher would be used on an electrical control panel that has been de-energized? a. Non-conductive extinguishing agent b. Class A c. Class B d. Class C e. All of the above if you are absolutely sure the panel is de-energized. Disinfection with chlorine is the more effective at a pH of 9.0 than that of 7.0 a. True b. False The biomass on a normal functioning RBC has what appearance? The sludge from a primary clarifier should contain what percent solids? According to 30 TAC Chapter 317, all pipe and fittings used in wastewater pressure mains shall have a minimum psi pressure rating of ________. Carbon monoxide (CO) poisoning symptoms are ________. The smallest pipe size for air recirculation of a self-priming centrifugal pump is ________. Dangerous gases in a confined space may not be detected with the physical senses because When setting work goals for an employee, the goals should be ________. According to Chapter 317, Design Criteria, a manhole can be installed within 9 feet of an existing waterline if ________. As the population of a collection system increases, the ratio of peak flow to average daily flow will ________. One important element of a good communicator is ________. When connecting a public water supply to any source of potential contamination, an air gap of what size must be provided? One of the requirements of the Texas Hazard Communication Act of 1985 is that the employer must hold annual training in which the utilities' written policies and the employee's rights are explained to ________. The Federal Clean Water Act ________.