Wastewater Class B Texas 2024-2025. Questions and Correct Verified Answers. Graded A, Exams of Water and Wastewater Engineering

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Wastewater Class B Texas 2024-2025.

Questions and Correct Verified Answers.

Graded A

______ are the smallest , most numerous, and most important of the activated sludge microorganisms - ANSbacteria ______ gas is colorless, odorless and heavier than air - ANSMethane ______ gas is very toxic and deadens the sense of ______ - ANSHydrogen Sulifide/smell _________ would most commonly be used to seal a number of joint leaks on a main with minimal interruption - ANSinternal grouting ____________gas is greenish-yellow, pungent, heaver than air and highly toxic - ANSchlorine ___________would have an adverse effect on the proper settling of solids in a clarifier. - ANSA short circuiting flow pattern __________in the effluent from an activated sludge process is a pollutant and may create toxic conditions for aquatic life in the receiving stream - ANSNitrogen _________removes Total Suspended Solids (TSS) - ANSfiltration

_________will increase the chances that sewage will turn septic - ANSStoppages in the main line A __________ pump would most likely be used when discharging into a 10" diameter pressure sewer main. - ANSCentrifugal A ____________ would be the best to determine if a storm drain is connected to a sanitary sewer line. - ANSSmoke Test A centrifugal pump must be ____ or it will not pump - ANSprimed A good plant influent pH is about - ANS7. A licensed wastewater operator is a professional - ANSconsistently 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 A mechanical device that screens & cuts large solids in small particles - ANSCumminuter A preferred hydraulic method of cleaning sewer lines is - ANSHydro Jet Cleaner A properly designed and operated primary sedimentation tank should remove _____ percent of incoming BOD - ANS30-40%

A Rotating Biological Contactor (RBC) is - ANSfixed firm biological treatment process A sewer manhole provides access into the system for cleaning or service. A manhole is located - ANSat changes in alignment, diameter, grade, direction and intersection A simple method for indicating when to waste sludge is - ANS30 minute settling test Acute toxicity occurs when - ANSThere is a rapid die off of treatment organisms Aerated Lagoons rely on ______ to provide ____and _____ - ANSMechanical aeration/ Aeration & mixing Aerobic Bacteria require_____ in the water for their metabolism - ANSoxygen Aerobic digestion is an ____process whereby the aerobic bacteria consume themselves - ANSEndogenous All reclaimed water piping must be _______in color - ANSpurple An effective way for the collection system worker to prevent infection by waterborn pathogenic organism is to - ANSWear protective clothing and avoid direct contact with waste water

An important step in testing a sample for Total Suspended Solids is - ANSFiltering a sample Anaerobic Bacteria _____ live with O2 present in the water for their metabolism - ANScannot Anaerobic digesters are covered to keep out ____, and to trap useful methane which can be used to keep the digester warm. - ANSfree oxygen Approved disposal methods for digested, dewatered, sludge's are landfill, ____ and ____. - ANSIncineration & Land Application Before entering a confined space a worker should - ANSUse 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 Before entering a manhole the operator should test for ________and oxygen levels and ________the manhole before entering. - ANSall hazardous gasses and ventilate Besides disinfection, chlorine has other uses at the wastewater treatment plant such as - ANSReduces BOD, Odor, Algae growth, Helps with Grease Calcium Hypochlorite (HTH) is a strong _______ and reacts violently with _________. - ANSOxidizer/Oil & Hydrocarbons

Chapter ___ of the Texas Water Code is the state law controlling water pollution and ___ authority to control discharges in Texas - ANSChapter 26 and Texas Commission of Environmental Quality Chemical characteristics of sewage include - ANSsolids, greases, dissolved oxygen, O2 Demand, pH, and gasses Chronic toxicity occurs when - ANSCertain microorganisms become inactivated but others continue to work resulting in a sick biological process Common operating problems with a trickling filter include - ANSPonding, Filter files, Odors, Clogging of Nozzles, & Snails Contributes to the infiltration in a collection system - ANSbreaks in the main lines, high ground water levels, heavy rains, hydro jet cleaning plugged mains Dangerous gases are produced during bacterial decomposition of organics in wastewater. The main gasses are - ANSHydrogen sulfide, carbon dioxide and methane Denitrification occurs in an activated sludge system when there is __________ to maintain the aerobic metabolism of the carbon stabilizing bacteria. - ANSInsufficient Dissolved Oxygen Detention time in wastewater typically refers to - ANSThe time sewage is kept in a sedimentation basis

Devices that may be used to determine the level of sewage in a lift station - ANSair bubbler, floats, electrodes, Acoustic (sonic) Digester gas typically contains about ________%_______ - ANS65-75% methane Dissolved Oxygen (DO) in aeration tank of an activated sludge plant should be maintained at or about - ANS2 to 4 mg/L 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 - ANSconsidered an unavoidable discharge, a violation of the Texas Water Code, a bypass that must be reported within 24 hours and considered a health hazard Each person contributes approximately ______ lbs of BOD to the system daily. - ANS0. Effluent dosage of chlorine in the contact chamber must produce a total combined residual of - ANS1.0 mg/L after 20 minutes Enforcement action from TCEQ may be taken if pollution or waste violates the Texas Water Code. Violations of Water Code may include - ANSUnauthorized discharge, accidental discharge & health hazard Essential components of the wastewater collection system include - ANSSewer mains & piping, Lift Stations, Pumps, Grease & Sand traps, & Manholes

Excessive power consumption by a pump could be caused by - ANSWorn bearings and worn impeller Extensive use of garbage disposals (grinders) in a community would likely have the following effect on the collection system - ANSIncrease the amount of flow, solids, and grease Facultative Bacteria require__________in the water for their metabolism - ANSeither aerobic or anaerobic conditions Facultative Lagoons have two zones of treatment - ANSan aerobic surface layer and an anaerobic bottom layer Force Mains and fittings must have a pressure rating of at least - ANS150 psi Grit removal would be considered - ANSA part of Primary Treatment Hydraulic loading refers to the volume of ____, including recirculation, applied to the filter - ANSwater If accidental discharge, bypass, or spill (SSO) of wastewater occurs the responsible party MUST notify TCEQ regional offices within ____ hours - ANS If the ____ loading on the plant is high, the operator would need to ____Dissolved Oxygen (DO) levels. - ANSOrganic/Increase

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. - ANS3 feet / 25 feet laterally In the activated sludge plant, good quality sludge will settle _________& _______ over _________ minute period. - ANSGently & Uniformly over 15 to 20 minutes In the activated sludge plant, old sludge quality will settle ________& _________ over ________ minute period. - ANSRapidly and ragged over 5 minutes. In the activated sludge plant, there are (5) important nitroen transformation processes that occur by microorganisms. They are- - ANSAssumilation, Ammonification, Nitrification, Denitrification, & Nitrogen fixation. In the activated sludge plants the operator will experience problems. Some of the common Influent problems include - ANSSeptic 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 Environmental problems include. - ANSLow temperatures, System pH out of range, & Excessive algae growth In the activated sludge plants, the operator will experience problems. Some common Operational problems include - ANSSludge quality, foaming, improper operating techniques In the activated sludge plants, the operator will experience problems. Some of the common Treatment plant problems include - ANSInsufficent capacity, Equipment

failures, Design inadequacies, Poor maintenance, & Inflow rates exceed plant capacities. In the activated sludge plants, to properly set the clarifier return rate the operator must know three things - ANSReturn activated sludge rate, Sludge blanket thickness, & the Solids concentration of the return flow In the activated sludge process aeration tanks provide the space necessary to _______, ________, & _______ and return biological solids. - ANSMix, aerate, & Hold Influent In the activated sludge process, "Classic Bulking" is a common problem typically caused by - ANSLow density sludge In the activated sludge process, as more mixed liquor flows to the clarifier, the thickness of the sludge blanket will - ANSIncrease 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 - ANSAir lift pumps, centrifugal pumps, Diaphragm pumps, Screw pumps & Gravity Flow In the activated sludge process, daily observation of the aeration basin treatment processes are essential. The operator should pay close attention to - ANSSurface 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 - ANSSurface scum, Sludge blanket, Weir Flow, Rising solids, & Clarifier overflow

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 _______. - ANS2 mg/L and 4.0 mg/L In the activated sludge process, factors that will influence the operation of the final clarifier are - ANSLoading, solids applied, settling, thickness of solids, rate of return & Wasting In the activated sludge process, five (5) Important control parameters are - ANSDissolved Oxygen level, Aerator solids level, Solids quality, Rate of returned sludge, & Wasting rate In the activated sludge process, floc is very important to the settling process. Floc is composed primarily of - ANSBacteria, Protozoa, Microscopic Animals, & Fungi 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. - ANSwater/ solids In the activated sludge process, Gould Sludge Age (GSA) is calculated by - ANSDividing the total pounds of TSS in the aerator by the pounds of TSS entering the aerator as raw In the activated sludge process, Mass Balance refers to - ANSMaintaining the balance between Return Sludge Flow, Return Sludge, Aeration tank volume, Mixed liquor suspended solids

In the activated sludge process, no sludge process will work properly without - ANSRegular removal of excess solids In the activated sludge process, Sludge Rising differs from "Sludge Bulking" and "Sludge Rising" is typically associated - ANSNitrification - De-nitrification process In the activated sludge process, Stabilization is - ANSWastes biologically converted to water, carbon dioxide, or new cells In the activated sludge process, techniques used to reduce "Frothing & Foaming" typically include - ANSAdjusting sludge age, Reducing the amount of air, Spraying the frothing area with water, Applying de-foaming agents In the activated sludge process, the _______ is called the heart of the activated sludge process. - ANSClarifier In the activated sludge process, the clarifier will concentrate return sludge and waste sludge about ___ to__ times the solids concentration of the mixed liquor - ANStwo (2) to four (4) In the activated sludge process, the F/M Ratio is calculated by ______ the pounds of _________ by the pounds of MLVSS in the ___________. - ANSDividing/ Incoming BOD/ aeration tank In the activated sludge process, the term Gould Sludge Age refers to - ANSHow long in days a pound of solids stays in the aerator

In the activated sludge process, the term Mean Cell Residence Time (MCRT) refers to - ANSThe amount of time the living cells are kept in the plant In the activated sludge process, the terms F/M ratio is important because this refers to - ANSFood to Microorganism Ratio In the activated sludge system if the operator observed uneven surface aeration, dead spots or inadequate mixing in some areas, the operator would suspect - ANSPlugged diffusers In the activated sludge system, "Hydraulic Wash Out" is - ANSWhen the upward movement of the water in the clarifier exceeds the downward settling velocity In the activated sludge system, Hydraulic Wash Out can be controlled by - ANSflow equalization, Additional clarifier capacity or inflow reduction In the activated sludge system, if the operator observed Boiling action, Violent turbulence throughout the aeration tank surface, Large air bubbles 1/2 inch or greater, the operator would suspect- - ANSOver aeration resulting in high DO and or floc shearing therefore the operator should reduce the air SCFM to get DO into the proper range In the activated sludge system, if the operator observes excessive air being used with no apparent change in organic or hydraulic loading, the operator would suspect - ANSLeaks in the system piping, Plugged air diffusers & High organic loading

In the activated sludge system, if the operator observes white thick billowing sudsy foam on the aeration tank, the operator would suspect - ANSOverloaded aeration tank and or excessive sludge wasting In the active sludge process, Utilization is the process where - ANSFood supply is changed into a liquid state for use In the past ____ was used to construct manholes. This product is prohibited for construction or grading today - ANSbrick and mortar Inflow and Infiltration (I&I) typically refers to - ANSunaccounted for water in the system after heavy rains Inorganic Solids (ash) are those that - ANSConsist of sand, grit, & minerals and can be suspended or dissolved Inorganic solids include - ANSsand, grit and minerals Landfill applied sludge must have a solids content of at least _________percent - ANS Most important to providing adequate sewage treatment in a stabilization pond - ANSsunlight, algae, bacteria and time Most pumping stations and electrical equipment used today in wastewater collection or treatment is ________ and typically either _______ or _________ volts - ANSA.C. (Alternating Current) & 220 or 440 and in some cases A.C. (Alternating Current) & 100 or 208

Needs to be checked regularly to properly operate an activated sludge treatment plant - ANSaeration equipment and mixed liquor solids New manholes must have an inside diameter of at least ______ feet and the entry access must be at least ____inches. - ANS4 feet and 24 inches Newly hired personnel have _________to become licensed. - ANS1 year Non-point discharges are - ANSdischarges that have intermittent, dispersed flows having little or no control Non-settleable Solids are - ANSSmall particles that do not settle Odors occur when treatment becomes - ANSanaerobic Offensive and objectionable odors which sometimes occur in trickling filters usually indicate - ANSseptic conditions are present One common type of weir design for measuring flow is - ANSV-Knotch Organic loading of a stabilization pond is about ____ pounds of BOD/acre/day with a detention time of at least ___ days. - ANS35 BOD/ 30 Days Organic loading refers to the pounds per day of ____ per acre feet or 1,000 cubic feet of filter media - ANSBOD

Organic matter in wastewater can be ______or________and makes up approximately _______% of the total solids - ANSDissolved or Suspended / 65 Organic solids include - ANSorganic materials from plants, animals or humans Point source discharges are - ANSdischarges that come from pipes or ditches that are monitored, controlled and inspected Pre-treatment of wastewater would include: - ANSCoarse or fine screening, grinding and grit removal and grease removal and pre-aeration Primary treatment of wastewater would include - ANSsettling tanks or basins, scum collection and removal, sludge collection and removal Secondary treatment typically used today would include - ANSStabilization ponds, trickling filters, rotating biological contractors (RBC) & activated sludge Settable Solids (SS) are those that - ANSSettle out when left standing for extended periods of time Solids in wastewater are classified as - ANSTotal (TR), Suspended (TSS), Dissolved (TDS), Settleable (SS), Non-setteable, Floatable, Organic and Inorganic Sources of waste water include - ANSdomestic, storm water, commercial, food processing, agricultural and industrial

TCEQ allows the reuse of wastewater, some of these include - ANSIrrigation, aquifer recharge, cooling towers and fire protection TCEQ may authorize discharge of untreated wastewater into or near a receiving stream in extreme cases. This is referred to as - ANSBypass The _____pump is most commonly used in a lift station - ANScentrifugal The Activated Sludge plant has five (5) Critical Components. They are - ANSOxygen supply, Aeration tanks, Clarifiers, Return & Waste The Activated Sludge Process can produce a high degree of treatment. Typically one could expect a ______to_______% BOD removal - ANS90 to 99% The Activated Sludge process is an ________process. - ANSAerobic The Biochemical oxygen Demand (BOD) of a sample is based on - ANSMeasuring the dissolved oxygen (DO) used The depth of sludge drawn to a drying bed should be - ANSApproximately 9 inches The efficiency of a trickling filter is measured in - ANSPercent BOD Removed The hydraulic loading of a trickling filter may be determined by - ANSflow rate and filter area

The lack of _________ triggers the facuitative bacteria to change from aerobic and anaerobic - ANSDissolved Oxygen The majority of Dissolved Oxygen in raw sewage comes from - ANSPotable Drinking Water The maximum safe withdrawal rate for a 150 lb chlorine cylinder is - ANS40 lbs The minimum separation between sewer lines and potable water lines is - ANS feet The minimum size for a gravity flow sewer line on city right-of-way and the minimum grade is - ANS6 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 - ANSObtaining actual flow data & verifying with field data The most common method of dewatering and drying sludge is - ANSdrying bed The most common type(s) of trickling filters are- - ANSStandard rate (1-4 mgd) and High Rate (10-40 mgd) The name of the State Agency responsible for enforcing pollution control laws in Texas - ANSTexas Commission of Environmental Quality The primary cause of stoppage in a collection system is _____ and _____ - ANSgrease/roots

The protozoa that causes dysentery would most likely be destroyed by - ANSDisinfection The results of Biochemical Oxygen Demand (BOD) sample taken at a treatment plant tells the operator - ANSHow the plant was operating 5 days ago The term pathogenic means - ANSCapable of causing disease The Texas Commission on Environmental Quality can revoke an operator's license if the operator - ANScauses permit violation, falsifies records or neglects their duty The Texas Water Code establishes the protection of water quality and quantity of the state by - ANSsetting stream standards, issues permits for discharges, identifies non-point source controls, and establishes water reuse. The typical pH of an influent entering the plant will vary from - ANS6.5 to 8. The typical sludge age for extended aeration plants is - ANS20 to 40 days The wastewater plant operator is primarily responsible for - ANStreating wastewater discharged into the community There are five (5) major components to a trickling filter - ANSFilter floor, underdrain, walls, filter media, & distributer arms

These can be used to dewater sludge - ANSbelt press, drying beds, solid bowl centrifuge, gravity thickener These diseases are caused by pathogenic organisms that may be present in raw wastewater - ANSHepatitis, typhoid, paratyphoid,dysentery, cholera, gastroenteritis, polio, hookworm and giardiasis This test would give the best information on how efficiently a trickling filter was operating - ANSPercent BOD Removal This treatment device is commonly used to separate and remove large solids from raw wastewater - ANSA Mechanically raked bar screen This trickling filter problem could be reduced by increasing the recirculation ratio - ANSFilter files To avoid electrical shock, the operator should ________ if they are experiencing equipment failures or power related issues - ANSRefer the problem to a trained electrical repairperson and do not attempt to check fuses or open the disconnect box and Notify the power provider and let them send out a serviceman to assure the problem is not on the provider's side. To determine the approximate number of gallons per day being discharged to the collection system, multiply the population by ____ gallons/person/day. - ANS Total Dissolved Solids (TDS) are those that - ANScannot be filtered out Total solids in wastewater are the sum of - ANSSettleable and volatile solids

Total Suspended Solids (TSS) are those that - ANSCan be filtered out Trench safety is a great concern in Texas. OSHA requires that anytime an excavation is greater than __ feet deep it must be protected by ______. - ANS feet / An approved Trench Box, Shoring, or Sloping Types of pipe that are commonly used in wastewater collection system - ANSductile iron, Poly Vinyl Chloride (PVC) Typically one could expect ____ % BOD removal in a Facultative Lagoon - ANS Unstable anareobic sludge contains streaks of _________ or ________. - ANSgray/green Using final plant effluent in cooling towers would be a - ANSBeneficial way to reuse treated effluent Verified clay and Poly Vinyl Chloride (PVC) are the most common pipe materials used for sewer lines but other materials are available such as - ANSductile iron, cast iron, acrylontrile butadiene styrene (ABS) Concrete, polyethylene & asbestos concrete Volatile Solids (VSS) are those that - ANSAre determined by burning the residue from the Total Solids determination

Wastewater Stabilization Ponds are an approved process for wastewater treatment. Organic loading of Stabilization Ponds is typically - ANS35 lbs BOD/Acre/Day with a minimum of 30 days detention time Wastewater Stabilization Ponds work through a complex process which includes - ANSSunlight, Oxygen, Nutrients, Algae, and Bacteria Ways to reduce bad odors coming from a collection system - ANSroutinely cleaning slow running or low flow lines, adding chlorine or hydrogen peroxide to the collection system What gases are produced by the controlled anaerobic digestion of wastewater sludge's - ANSMethane & Carbon Dioxide What is the greatest advantage for using fiberglass manholes in areas with high groundwater? - ANSfiberglass is not subject to infiltration What is the most important role of aerobic bacteria in the treatment of wastewater? - ANSdecompose organic matter When a centrifuge pump loses prime the - ANSpump is no longer moving liquid When a municipal wastewater effluent has a high nitrate level and low ammonia level this most likely means - ANSthe effluent has received a high degree of aerobic treatment When added to water chlorine forms _____&_______acid - ANSHydrochlorous and Hydrochloric

When ammonia is present in wastewater and reacts with chlorine_________are formed - ANSChloramines When using Hydraulic Hydro Jetting sewer cleaning equipment the operator will want to go from a _______ manhole and clean toward the stoppage to avoid _________. - ANSClear or open / Forcing sewage into customer homes or businesses Whenever wastewater cannot flow to the treatment plant by _____ a _____ is typically used - ANSgravity/ lift station Which of the following are dangerous gasses that are likely to be present in lift stations and manholes? - ANSNatural gas, gasoline fumes, hydrogen sulfide and carbon dioxide Zoogleal Mass refers to - ANSA thick layer of jelly like slime where organisms bacteria, fungi, protozoa and ciliates thrive.