Wastewater Class B Texas Questions and answers Wastewater Class B Texas Questions and ans, Exams of Water and Wastewater Engineering

Download Wastewater Class B Texas Questions and answers Wastewater Class B Texas Questions and ans and more Exams Water and Wastewater Engineering in PDF only on Docsity! Wastewater Class B Texas Questions and answers The name of the State Agency responsible for enforcing pollution control laws in Texas CORRECT ANSWERS✅ Texas Commission of Environmental Quality. The term pathogenic means CORRECT ANSWERS✅ Capable of causing disease. The minimum separation between sewer lines and potable water lines is CORRECT ANSWERS✅ 9 feet. A licensed wastewater operator is a professional CORRECT ANSWERS✅ 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 CORRECT ANSWERS✅ Filtering a sample The Biochemical oxygen Demand (BOD) of a sample is based on CORRECT ANSWERS✅ Measuring the dissolved oxygen (DO) used Wastewater Class B Texas Questions and answers The results of Biochemical Oxygen Demand (BOD) sample taken at a treatment plant tells the operator CORRECT ANSWERS✅ How the plant was operating 5 days ago Which of the following are dangerous gasses that are likely to be present in lift stations and manholes? CORRECT ANSWERS✅ Natural gas, gasoline fumes, hydrogen sulfide and carbon dioxide A preferred hydraulic method of cleaning sewer lines is CORRECT ANSWERS✅ Hydro Jet Cleaner Ways to reduce bad odors coming from a collection system CORRECT ANSWERS✅ routinely cleaning slow running or low flow lines, adding chlorine or hydrogen peroxide to the collection system Types of pipe that are commonly used in wastewater collection system CORRECT ANSWERS✅ ductile iron, Poly Vinyl Chloride (PVC) Before entering a confined space a worker should CORRECT ANSWERS✅ 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 Wastewater Class B Texas Questions and answers Point source discharges are CORRECT ANSWERS✅ discharges that come from pipes or ditches that are monitored, controlled and inspected Non-point discharges are CORRECT ANSWERS✅ 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 CORRECT ANSWERS✅ setting stream standards, issues permits for discharges, identifies non-point source controls, and establishes water reuse. The wastewater plant operator is primarily responsible for CORRECT ANSWERS✅ 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 CORRECT ANSWERS✅ Chapter 26 and Texas Commission of Environmental Quality The Texas Commission on Environmental Quality can revoke an operator's license if the operator CORRECT ANSWERS✅ causes permit violation, falsifies records or neglects their duty Wastewater Class B Texas Questions and answers If accidental discharge, bypass, or spill (SSO) of wastewater occurs the responsible party MUST notify TCEQ regional offices within ____ hours CORRECT ANSWERS✅ 24 Aerobic Bacteria require_____ in the water for their metabolism CORRECT ANSWERS✅ oxygen Anaerobic Bacteria _____ live with O2 present in the water for their metabolism CORRECT ANSWERS✅ cannot Facultative Bacteria require__________in the water for their metabolism CORRECT ANSWERS✅ either aerobic or anaerobic conditions Chemical characteristics of sewage include CORRECT ANSWERS✅ solids, greases, dissolved oxygen, O2 Demand, pH, and gasses _________removes Total Suspended Solids (TSS) CORRECT ANSWERS✅ filtration Inorganic solids include CORRECT ANSWERS✅ sand, grit and minerals Wastewater Class B Texas Questions and answers Organic solids include CORRECT ANSWERS✅ organic materials from plants, animals or humans A good plant influent pH is about CORRECT ANSWERS✅ 7.2 Dangerous gases are produced during bacterial decomposition of organics in wastewater. The main gasses are CORRECT ANSWERS✅ Hydrogen sulfide, carbon dioxide and methane The majority of Dissolved Oxygen in raw sewage comes from CORRECT ANSWERS✅ Potable Drinking Water Each person contributes approximately ______ lbs of BOD to the system daily. CORRECT ANSWERS✅ 0.17 Sources of waste water include CORRECT ANSWERS✅ domestic, storm water, commercial, food processing, agricultural and industrial Wastewater Class B Texas Questions and answers The most common type(s) of trickling filters are- CORRECT ANSWERS✅ Standard rate (1-4 mgd) and High Rate (10-40 mgd) Odors occur when treatment becomes CORRECT ANSWERS✅ anaerobic ____________gas is greenish-yellow, pungent, heaver than air and highly toxic CORRECT ANSWERS✅ chlorine One common type of weir design for measuring flow is CORRECT ANSWERS✅ V- Knotch Inflow and Infiltration (I&I) typically refers to CORRECT ANSWERS✅ 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. CORRECT ANSWERS✅ Organic/Increase A simple method for indicating when to waste sludge is CORRECT ANSWERS✅ 30 minute settling test Wastewater Class B Texas Questions and answers Organic loading of a stabilization pond is about ____ pounds of BOD/acre/day with a detention time of at least ___ days. CORRECT ANSWERS✅ 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. CORRECT ANSWERS✅ free oxygen Unstable anareobic sludge contains streaks of _________ or ________. CORRECT ANSWERS✅ gray/green Aerobic digestion is an ____process whereby the aerobic bacteria consume themselves CORRECT ANSWERS✅ Endogenous Approved disposal methods for digested, dewatered, sludge's are landfill, ____ and ____. CORRECT ANSWERS✅ Incineration & Land Application Landfill applied sludge must have a solids content of at least _________percent CORRECT ANSWERS✅ 20 Wastewater Class B Texas Questions and answers Calcium Hypochlorite (HTH) is a strong _______ and reacts violently with _________. CORRECT ANSWERS✅ Oxidizer/Oil & Hydrocarbons When added to water chlorine forms _____&_______acid CORRECT ANSWERS✅ Hydrochlorous and Hydrochloric When ammonia is present in wastewater and reacts with chlorine_________are formed CORRECT ANSWERS✅ Chloramines Effluent dosage of chlorine in the contact chamber must produce a total combined residual of CORRECT ANSWERS✅ 1.0 mg/L after 20 minutes Besides disinfection, chlorine has other uses at the wastewater treatment plant such as CORRECT ANSWERS✅ Reduces BOD, Odor, Algae growth, Helps with Grease TCEQ allows the reuse of wastewater, some of these include CORRECT ANSWERS✅ Irrigation, aquifer recharge, cooling towers and fire protection All reclaimed water piping must be _______in color CORRECT ANSWERS✅ purple Wastewater Class B Texas Questions and answers _________will increase the chances that sewage will turn septic CORRECT ANSWERS✅ Stoppages in the main line Extensive use of garbage disposals (grinders) in a community would likely have the following effect on the collection system CORRECT ANSWERS✅ 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 CORRECT ANSWERS✅ 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 CORRECT ANSWERS✅ Obtaining actual flow data & verifying with field data What is the greatest advantage for using fiberglass manholes in areas with high groundwater? CORRECT ANSWERS✅ fiberglass is not subject to infiltration A __________ pump would most likely be used when discharging into a 10" diameter pressure sewer main. CORRECT ANSWERS✅ Centrifugal Wastewater Class B Texas Questions and answers Excessive power consumption by a pump could be caused by CORRECT ANSWERS✅ 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 ______. CORRECT ANSWERS✅ 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. CORRECT ANSWERS✅ 3 feet / 25 feet laterally A ____________ would be the best to determine if a storm drain is connected to a sanitary sewer line. CORRECT ANSWERS✅ Smoke Test _________ would most commonly be used to seal a number of joint leaks on a main with minimal interruption CORRECT ANSWERS✅ internal grouting Pre-treatment of wastewater would include: CORRECT ANSWERS✅ Coarse or fine screening, grinding and grit removal and grease removal and pre-aeration Wastewater Class B Texas Questions and answers Primary treatment of wastewater would include CORRECT ANSWERS✅ settling tanks or basins, scum collection and removal, sludge collection and removal Secondary treatment typically used today would include CORRECT ANSWERS✅ Stabilization ponds, trickling filters, rotating biological contractors (RBC) & activated sludge Essential components of the wastewater collection system include CORRECT ANSWERS✅ Sewer mains & piping, Lift Stations, Pumps, Grease & Sand traps, & Manholes Grit removal would be considered CORRECT ANSWERS✅ A part of Primary Treatment The protozoa that causes dysentery would most likely be destroyed by CORRECT ANSWERS✅ Disinfection Using final plant effluent in cooling towers would be a CORRECT ANSWERS✅ Beneficial way to reuse treated effluent Wastewater Class B Texas Questions and answers Chronic toxicity occurs when CORRECT ANSWERS✅ 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 CORRECT ANSWERS✅ Cumminuter Detention time in wastewater typically refers to CORRECT ANSWERS✅ The time sewage is kept in a sedimentation basis There are five (5) major components to a trickling filter CORRECT ANSWERS✅ Filter floor, underdrain, walls, filter media, & distributer arms Zoogleal Mass refers to CORRECT ANSWERS✅ A thick layer of jelly like slime where organisms bacteria, fungi, protozoa and ciliates thrive. The efficiency of a trickling filter is measured in CORRECT ANSWERS✅ Percent BOD Removed Wastewater Class B Texas Questions and answers Common operating problems with a trickling filter include CORRECT ANSWERS✅ Ponding, Filter files, Odors, Clogging of Nozzles, & Snails Wastewater Stabilization Ponds are an approved process for wastewater treatment. Organic loading of Stabilization Ponds is typically CORRECT ANSWERS✅ 35 lbs BOD/Acre/Day with a minimum of 30 days detention time Wastewater Stabilization Ponds work through a complex process which includes CORRECT ANSWERS✅ Sunlight, Oxygen, Nutrients, Algae, and Bacteria Facultative Lagoons have two zones of treatment CORRECT ANSWERS✅ an aerobic surface layer and an anaerobic bottom layer Typically one could expect ____ % BOD removal in a Facultative Lagoon CORRECT ANSWERS✅ 50 Aerated Lagoons rely on ______ to provide ____and _____ CORRECT ANSWERS✅ Mechanical aeration/ Aeration & mixing Wastewater Class B Texas Questions and answers The most common method of dewatering and drying sludge is CORRECT ANSWERS✅ drying bed Digester gas typically contains about ________%_______ CORRECT ANSWERS✅ 65-75% methane The depth of sludge drawn to a drying bed should be CORRECT ANSWERS✅ Approximately 9 inches Newly hired personnel have _________to become licensed. CORRECT ANSWERS✅ 1 year Force Mains and fittings must have a pressure rating of at least CORRECT ANSWERS✅ 150 psi Most pumping stations and electrical equipment used today in wastewater collection or treatment is ________ and typically either _______ or _________ volts CORRECT ANSWERS✅ A.C. (Alternating Current) & 220 or 440 and in some cases A.C. (Alternating Current) & 100 or 208 Wastewater Class B Texas Questions and answers 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. CORRECT ANSWERS✅ water/ solids In the activated sludge process, as more mixed liquor flows to the clarifier, the thickness of the sludge blanket will CORRECT ANSWERS✅ 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 CORRECT ANSWERS✅ Air lift pumps, centrifugal pumps, Diaphragm pumps, Screw pumps & Gravity Flow In the activated sludge process, no sludge process will work properly without CORRECT ANSWERS✅ Regular removal of excess solids In the activated sludge process, Mass Balance refers to CORRECT ANSWERS✅ Maintaining the balance between Return Sludge Flow, Return Sludge, Aeration tank volume, Mixed liquor suspended solids Wastewater Class B Texas Questions and answers In the activated sludge process, the terms F/M ratio is important because this refers to CORRECT ANSWERS✅ 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 ___________. CORRECT ANSWERS✅ Dividing/ Incoming BOD/ aeration tank In the activated sludge process, the term Gould Sludge Age refers to CORRECT ANSWERS✅ How long in days a pound of solids stays in the aerator In the activated sludge process, Gould Sludge Age (GSA) is calculated by CORRECT ANSWERS✅ 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 CORRECT ANSWERS✅ 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 CORRECT ANSWERS✅ Surface turbulence, Foam, Odors, & Color Wastewater Class B Texas Questions and answers In the activated sludge process, daily observation of the final clarifier is also essential. The operator should pay close attention to CORRECT ANSWERS✅ Surface scum, Sludge blanket, Weir Flow, Rising solids, & Clarifier overflow In the activated sludge process, five (5) Important control parameters are CORRECT ANSWERS✅ 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 _______. CORRECT ANSWERS✅ 2 mg/L and 4.0 mg/L In the activated sludge process, "Classic Bulking" is a common problem typically caused by CORRECT ANSWERS✅ Low density sludge In the activated sludge process, Sludge Rising differs from "Sludge Bulking" and "Sludge Rising" is typically associated CORRECT ANSWERS✅ Nitrification - De- nitrification process Wastewater Class B Texas Questions and answers In the activated sludge plant, there are (5) important nitroen transformation processes that occur by microorganisms. They are- CORRECT ANSWERS✅ 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 CORRECT ANSWERS✅ Nitrogen Denitrification occurs in an activated sludge system when there is __________ to maintain the aerobic metabolism of the carbon stabilizing bacteria. CORRECT ANSWERS✅ Insufficient Dissolved Oxygen The lack of _________ triggers the facuitative bacteria to change from aerobic and anaerobic CORRECT ANSWERS✅ Dissolved Oxygen In the activated sludge system, "Hydraulic Wash Out" is CORRECT ANSWERS✅ When 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 CORRECT ANSWERS✅ flow equalization, Additional clarifier capacity or inflow reduction Wastewater Class B Texas Questions and answers 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- CORRECT ANSWERS✅ Over 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 observed uneven surface aeration, dead spots or inadequate mixing in some areas, the operator would suspect CORRECT ANSWERS✅ Plugged diffusers In the activated sludge system, if the operator observes white thick billowing sudsy foam on the aeration tank, the operator would suspect CORRECT ANSWERS✅ Overloaded aeration tank and or excessive sludge wasting 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 CORRECT ANSWERS✅ Leaks in the system piping, Plugged air diffusers & High organic loading Wastewater Class B Texas Questions and answers The maximum safe withdrawal rate for a 150 lb chlorine cylinder is CORRECT ANSWERS✅ 40 lbs To determine the approximate number of gallons per day being discharged to the collection system, multiply the population by ____ gallons/person/day. CORRECT ANSWERS✅ 100