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

Download TEXAS WASTEWATER CLASS B EXAM 2024-2025 and more Exams Nursing in PDF only on Docsity! 1 | P a g e TEXAS WASTEWATER CLASS B EXAM 2024-2025 WITH ACTUAL CORRECT QUESTIONS AND VERIFIED DETAILED ANSWERS |FREQUENTLY TESTED QUESTIONS AND SOLUTIONS |ALREADY GRADED A+|NEWEST|GUARANTEED PASS |LATEST UPDATE 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 2 | P a g e _________ 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 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 (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 cannot be filtered out 5 | P a g e When using Hydraulic Hydro Jetting sewer cleaning equipment the operator will want to go from a _______ manhole and clean toward the stoppage to avoid _________. Clear or open / Forcing sewage into customer homes or businesses The Activated Sludge Process can produce a high degree of treatment. Typically one could expect a ______to_______% BOD removal 90 to 99% The Activated Sludge plant has five (5) Critical Components. They are Oxygen supply, Aeration tanks, Clarifiers, Return & Waste The Activated Sludge process is an ________process. Aerobic In the activated sludge process aeration tanks provide the space necessary to _______, ________, & _______ and return biological solids. Mix, aerate, & Hold Influent In the active sludge process, Utilization is the process where Food supply is changed into a liquid state for use In the activated sludge process, Stabilization is Wastes biologically converted to water, carbon dioxide, or new cells 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 clarifier 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 clarifier, the thickness of the sludge blanket will Increase as solids accumulate 6 | P a g e 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 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 7 | P a g e 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 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 10 | P a g e Use approved monitoring device and check for the presence of dangerous gasses, ventilate the space with a blower, wear a safety harness and attach a life line A properly designed and operated primary sedimentation tank should remove _____ percent of incoming BOD 30-40% Devices that may be used to determine the level of sewage in a lift station air bubbler, floats, electrodes, Acoustic (sonic) What is the most important role of aerobic bacteria in the treatment of wastewater? decompose organic matter The hydraulic loading of a trickling filter may be determined by flow rate and filter area These can be used to dewater sludge belt press, drying beds, solid bowl centrifuge, gravity thickener Most important to providing adequate sewage treatment in a stabilization pond sunlight, algae, bacteria and time Offensive and objectionable odors which sometimes occur in trickling filters usually indicate septic conditions are present Dissolved Oxygen (DO) in aeration tank of an activated sludge plant should be maintained at or about 2 to 4 mg/L Contributes to the infiltration in a collection system breaks in the main lines, high ground water levels, heavy rains, hydro jet cleaning plugged mains When a centrifuge pump loses prime the pump is no longer moving liquid A Rotating Biological Contactor (RBC) is fixed firm biological treatment process Needs to be checked regularly to properly operate an activated sludge treatment plant aeration equipment and mixed liquor solids Point source discharges are discharges that come from pipes or ditches that are monitored, controlled and inspected 11 | P a g e Non-point discharges are discharges that have intermittent, dispersed flows having little or no control The Texas Water Code establishes the protection of water quality and quantity of the state by setting stream standards, issues permits for discharges, identifies non-point source controls, and establishes water reuse. The wastewater plant operator is primarily responsible for treating wastewater discharged into the community Chapter ___ of the Texas Water Code is the state law controlling water pollution and ___ authority to control discharges in Texas Chapter 26 and Texas Commission of Environmental Quality 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 12 | P a g e 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 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 Verified 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, acrylontrile 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 ______ 15 | P a g e Settleable and volatile solids This treatment device is commonly used to separate and remove large solids from raw wastewater A Mechanically raked bar screen ___________would have an adverse effect on the proper settling of solids in a clarifier. A short circuiting flow pattern This test would give the best information on how efficiently a trickling filter was operating Percent BOD Removal This trickling filter problem could be reduced by increasing the recirculation ratio Filter files What gases are produced by the controlled anaerobic digestion of wastewater sludge's Methane & Carbon Dioxide These diseases are caused by pathogenic organisms that may be present in raw wastewater Hepatitis, typhoid, paratyphoid,dysentery, cholera, gastroenteritis, polio, hookworm and giardiasis During heavy rain it is possible that manholes and lift stations may overflow, discharge waste materials into roadways or ditches. This type of discharge (SSO) would be considered an unavoidable discharge, a violation of the Texas Water Code, a bypass that must be reported within 24 hours and considered a health hazard An effective way for the collection system worker to prevent infection by waterborn pathogenic organism is to Wear protective clothing and avoid direct contact with waste water _________will increase the chances that sewage will turn septic Stoppages in the main line Extensive use of garbage disposals (grinders) in a community would likely have the following effect on the collection system Increase the amount of flow, solids, and grease 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 16 | P a g e Bio-monitoring involves the use of aquatic life to test the toxicity of a wastewater treatment plant effluent. TRUE The definition of an oxygen-deficient atmosphere is one that contains less than, what percentage of oxygen? 19.5 1.) What is the function of a grit auger? To Separate Organic from Inorganics 2.) Running a 30 min settling test is the best indication of what? What is taking place in the Clarifier. 3.) How many inches do you pour a sludge drying bed? 8 to 12 4.) Why do you draw sludge into the drying bed at a slow rate? To promote drying of the sludge. 5.) In the F/M ratio what does the food stand for? Organics 6.) What can chlorine be used for in a trickiling filter? Reduce Ponding 7.) One part of liquid chlorine equals how much of Gas? 450 8.) What is the purpose of a pretreatment program? To cut cost and help with plant efficiency 9.) In a composite sample there was a Cl2 sample ran and there was no residual present, what does that say about the sample? Inaccurate, Cl2 test is within 15 min, not 24 hours later 10.) In order to be a good communicator, what else do you need to be? Listener 11.) During Nitrification, which organisms use ______ for food? Nitrates In an Activated Sludge Treatment Process what is the most predominant organism? 17 | P a g e Ciliates and rotifers with few flagellates. The Detention Time in a Contact Stabilization plant is _____ than other extended aeration plants. Longer 14.) Other than disinfection chlorination can be used for what? Odor Control, Foaming, Reduce Algae Growth 15.) A leaking chlorine cylinder will do what? Have a frosty coated outside 16.) Who has the right to training and education? Everyone 17.) When connecting a potable water line to a wastewater pump for cooling, what do you need to put in place? Check Valve What is the expected % of removal of the settable solids from a primary clarifier? 90% to 99%) 19.) Manholes should be placed where? Every 500ft, change in elevation, pipe size or all of the above 20.) A high SVI would represent what about your sludge? Bulking sludge 21.) Grinder pumps are considered for what? A vital part of the collection system 22.) The main purpose for pretreatment is what? To cut cost and help with plant efficiency 23.) One reason you would not have to turn in a monthly report to the local reporting agency? Facility has not been constructed yet Aquifer recharge with plant EFF can be used for? Prevention of Salt Water intrusion, reduction of subsidence, replenishing of groundwater, all of the above. 25.) In a facultative, good operation means to? Adequate DO in the upper level of the pond. 20 | P a g e SVI= Sludge Volume Index. What does a SVI of 180 indicate? Poor Sludge Using a pump curve you have a pump impeller 14 ¾" pumping at 47 feet of head a static loss on the discharge of 4 feet. What will the pump put out? 47+4= 51ft of head How fast should you waste into the drying bed? Digester sludge should be put in slowly or sludge may become watery What will a grit removal system remove? (High Specific Gravity Materials.) (also mineral matter, such as sand, gravel, cinders, and other materials having a high inorganic content, It is used for removal of inorganic) What is facultative bacteria using or consuming when clarifier is nitrifying? Sulfate and Carbon Dioxide as Oxygen Source Who is responsible for a pressure system if you have grinder pumps located at residence? Homeowner When an aerobic digester process is improving what will you see? CO2 levels going down and methane increasing Activated Carbon is used physical-chemical treatment of wastewater to remove primarily dissolve organic pollutants or dissolve solids 67.) Refer to Exhibit D the function of float switch B is to turn? Turn circuit on and off For a 5MGD primary plant, if the raw sludge solids volatile content is 81 percent and the digested sludge solids volatile content is 69 percent, what percent of the volatile solids are being converted to gas? (That is , determined the percent reduction of the volatile solids.) (81-69) / 81=14.8 or 15% A trickling filter reduces the strength of the wastewater applied to it by filtering and straining action of the stones or support media. False "Treatment" What type of activated sludge plant operates near logarithmic growth? Contact Stabilization Good settling sludge in an activated sludge plant is indicated by the relative predominance of? 21 | P a g e Rotifiers and Celiates For a 5MGD primary plant, if the raw sludge solids volatile content is 81 percent and the digested sludge solids volatile content is 69 percent, what percent of the volatile solids are being converted to gas? That is, determined the percent reduction of the volatile solids.) (81-69) / 81=14.8 or 15% Complete mix plants will handle shock loads than other activated sludge modification. True A combustible atmosphere Oxygen, Flammable Gas, Fumes, and Dust What is the benefit of using effluent for aquifers recharge? Increase groundwater supply, reduce ground subsidence, and prevent saltwater intrusion How can you ensure the best results from a laboratory? Quality Control/ Quality Assurance When a chlorine cylinder has a leak? The container will form ice on the outside Whole-Part / Whole x 100 = % Reduction Area of Cylinder lbs per day / MGD x 8.34 x MG/L Besides disinfection, chlorination can be used in wastewater treatment processes to: 1.) pre-chlorinate influent for control of hydrogen sulfide 2.) remove nitrogen by break-point chlorination. 3.) Dose RAS for control of bulking or foaming. 4.) Reduce plugging in a trickling filter "ALL OF THE ABOVE" A 24 hour composite sample was tested for a chlorine residual and found to contain none. The results indicate that: Residual Chlorine was not present during the 24 hour period. Refer to exhibit D. The function of float B is to turn: The back up pump on. Float A is: Pump 1 on and all pumps off 22 | P a g e Float B is: pump 2 or back up pump on Float C is High warning light If the inside diameter of the lift station wet well for exhibit D is 6 ft and the vertical separation between "pump on" and "low water line" is 4 ft, the approximate storage is" 850 gallons (3.14x3x3x4x7.48=845.54) Proper operation of a facultative pond system requires that: adequate DO be maintained at the surface at all times. An efficient primary clarifier is expected to remove _________ of the influent settable solids. 90%or better Which of the following is NOT a recommended procedure (under normal conditions) to reduce or control "bulking" in an activated sludge system? Maintain less than normal amount of activated sludge solids. The white, thick billowing foam common during the start-up of a activated sludge wastewater treatment plant results from a low MLSS. True Activated carbon is used in physical chemical treatment of wastewater to remove primarily? Phosphorus You have a ditch that is 350 ft long, 2 ft wide, 10 ft deep, after you put bedding gravel and pipe into the ditch it fills it by 1/3. When you fill the remainder of the ditch, how many cubic yards of material will be hauled off. 86.42 yards. (350x2x10=7000/27=259.2/3= 86.42) You have an 8 ft diameter and 14 ft and 9 inches in depth, what is the amount of gallons in a wet well between the first mercury switch and the last switch. The floats are set at 2 ft and 7 inches apart. 970.697 or 971 gallons. Using a pump curve, you have a pump impeller 14 3/4 inches pumping at a 47 feet of head with a static loss on the discharge of 4 ft, what will the pump put out? How fast should you waste into a drying bed? Digester sludge should be slowly put in, to prevent from ripping the sludge blanket in the digester. What is the depth on a drying sludge bed? 25 | P a g e Air Gap Liquid CL2 expands? 1 cubic foot of liquid chlorine expands to occupy about 450 cubic feet as gas The high rate and low rate on an anaerobic digester refers to what? Importance of recirculating rate on a trickling filter is? Decreases or eliminates the opportunity for fly breeding. Reduces the strength of sewage applied to the filter. Increases the flow rate through a filter, causing continuous unloading and reduces ponding. Reseeds filter beds continuously. Reduces odors in primary tanks and reduces detention time, thereby reducing tendency toward septicity in primary tanks, and also reduces scum formation. Bio mass in extended aeration is kept in constant what? Flux Diversified What are primary treatment processes in activated sludge treatment? Primary Clarifier The most important consideration in planning a pretreatment program is? Identifying the industries and the characteristics of the waste that they produce so as not to cause damage to the collection system or cause the wastewater treatment plant to get upset. What are the primary considerations when applying for a permit? The availability of sewer service What does facultative bacteria consume during the activated sludge process? You have a flow of 1.7 MGD with a clarifier that is 50 ft in diameter, what would the overflow rate be in cf/gal? 866.24 (1.7 x 1,000,000 = 1,700,000 / 3.14 x 25 x 25 = 1962.5)= 866.24 What is F in F/M ratio? Food Influent BOD/ COD A screw conveyor on an incline in a grit removal system is for what? To wash the organic out of the grit Who is responsible for a pressure system if you have a grinder system at the residence? Optional/ owner resident/ electrical local, local plumber/ part of the sewer system. How can you tell when your digester is getting better? The methane is going up and the carbon is going down. 26 | P a g e What is the important part of the use of lab equipment? QA and QC/ Staff knows how to use it with the manufactures recommendation When an anaerobic digester is decreasing, you will see what? CO2 levels going down and methane levels increase