Class A Water Operator Test Questions and Complete Solution

Class A Water Operator Test Questions and Complete Solutions How many Training Hours and experience for a class D Water Operator - Answer: 16 Hours Training and No Experience How many Training Hours and experience for a class C Water Operator - Answer: 36 Hours Training and 1 year Experience How many Training Hours and experience for a class B Water Operator - Answer: 100 Hours Training and 3 years Experience (must include 1 year of hands on experience) How many Training Hours and experience for a class A Water Operator - Answer: 200 Hours Training and 5 years Experience (must include 2 years of hands on experience) How many Training Hours and experience for a Class C Lab Operator - Answer: 32 Hours and no experience How many Training Hours and experience for a Class B Lab Operator - Answer: 32 hours of C and 32 hours of B and 6 months experience. ***associate in science can substitute 32hrs of C level training How many Training Hours and experience for a Class A Lab Operator - Answer: 32 hours of B and 1 year experience. ***Must include a Bachelor in science How many Training Hours and experience for a Class C Distribution Operator - Answer: 36hours and 1 year experience How many Training Hours and experience for a Distribution Technician - Answer: 8 hours and no training. Community Water System - Answer: A public water supply that has at least 15 service connections or serves 25 or more persons on a regular basis Primary Contaminants - Answer: Contaminants identifies by the EPA as harmful to umal health Maximum Containment Level (MCL) - Answer: The level in which contaminants must not exceed or public notification is required. Cryptosporidium - Answer: A microsocpic parasite that can be found in water. It produces cysts that are very resistant to harsh environmental conditions. It is responsible for intestinal illness called cryptosporidiosis. Symptoms include diarrhea, cramps, gas, bodily discomfort, fatigue, and weight loss. Occurs one week after exposure and can last for 1-4 weeks Disinfection Profiling - Answer: A water system assesses the level of disinfection currently provided and then determines the impact a proposed change in disinfection practice would have. E. coli - Answer: A bacterium that is commonly used as an indicator of human health risk from harmful micro organisms that can be present in water. Symptoms include sever cramps and diarrhea. Blood is often seen in the stool. Symptoms begin 1-9 days after exposure and last a week or less. Giardia - Answer: A microscopic parasite that can be found in water. It produces cysts that are resistant to harsh environmental conditions. Giardia causes intestinal illness called giardiasis. Symptoms simular to cryptosporidiosis. Vomition, chills, headache and fever may also occur. Symptoms begin one week after exposure and can last up to a month. Hard Water - Answer: A characteristic of water caused mainly by the salts of calcium (Ca++) and magnesium (Mg++). Undesirable due to formation of soap curds, increase use of soap, and scale deposits in boilers and water heaters. Defines as having hardness of 100mg/L or greater Maximum Residual Disinfectant Level (MDRLs) - Answer: The highest level of disinfectant allowed in drinking water. Standards set by the US EPA Microbial Pathogens - Answer: Micro-organisms that cause disease Safe Drinking Water Act (SDWA) - Answer: An Act passed by the US Congress in 1974. It establishes a cooperative program among local, state, and federal agencies to ensure safe drinking water for customers. Ch 1 - One gallon of water weighs - Answer: 8.34 pounds Ch 1- The average domestic water usage per person per day is usually somewhere in the range of - Answer: 100-130 gallons Ch 1 -Probably the most important source of information to use when implementing changes in process control at a water plant is - Answer: Lab Results Ch 1 - The most important duty of a water plant operator is to - Answer: Help to protect the health and well-being of the community Apparent color - Answer: The color visible in water True color - Answer: Dissolved material contribution to color and is not removed through simple filtration (i.e. coffee or tea). Measure in Color Units (CUs) using a clear glass tube called a Nessler tub. Turbidity - Answer: Particles suspended in water. These particles can be removed through filtration. This is considered a primary contaminant by the EPA. These particles can surround and protect harmful microorganisms from being destroyed by chlorination. Nephelometric Turbidity Unit (NTUs) - Answer: A measure of turbidity H+ - Answer: hydrogen ion OH- - Answer: hydroxide ion Carbonate Hardness (CH) - Answer: Temporary hardness which is always alkalinity. Calcium and magnesium ion combine with carbonate, bicarbonate, and hydroxide ions to form carbonate hardness. Carbonate Hardness precipitates out with heat. Noncarbonate Hardness (NCH) - Answer: Permanent Hardness. Calcium and magnesium combine with sulfate and chloride ions the result is non-carbonate hardness. (Noncarbonate hardness = total hardness - total alkalinity) Alkalinity - Answer: The ability to resist changes in pH in response to dilute acids or dilute bases. While pH tends to be high with high alkalinity, it is not always the case. Alkalinity can be present in low pH conditions as well. Chemical ions that form Alkalinity - Answer: Hydroxide (OH-), carbonate (CO3--), and bicarbonate (HCO-). The pH of water determines which of these three ions are present Total alkalinity (T-alk) - Answer: The total amount of alkalinity present). Has a pH of between 4.5-14.0. Water with pH less than 4.5 has zero alkalinity. Phenolphthalein Alkalinity (P-alk) - Answer: A measurement of alkalinity. If pH is less than 8.3, no P-alk will be present. Measures concentrations of hydroxide, carbonate, and bicarbonate in the sample. Part of the total alkalinity. Colloids - Answer: Suspended Solids that do not settle out in water Faculative organisms - Answer: can live with or without oxygen Historically, the five major water-borne diseases have been - Answer: typhoid, cholera, dysentery, polio, and hepatitis (jaundice). Most common water borne disease - Answer: Giardiasis Coliform bacteria - Answer: non pathogenic bacteria often found in the intestinal tract of animals; monitored as in "indicator" of fecal contamination of water Colilert test - Answer: -a test to indicate contamination by coliform bacteria in drinking water. -qualitative test: test indicates presence or absence; not how much MPN (Most Probable Number) test - Answer: a statistical determination of the number of coliforms per 100ml of water MF (Membrane filter) test - Answer: Sometimes used to measure the total coliform and fecal coliform of water. Water is filtered and the coliform is then grown into colonies and counted to determine concentration in the initial sample. Maximum time between sample collection and analysis for bac-t - Answer: 30 hours but operators are encouraged to submit samples within 24 hours to be safe. Where can samples be collected for bac-t - Answer: only from sites listed on the Pre-approved site sampling plan. Ch 2 -The organisms used as an indicator of microbiological contamination are - Answer: Coliform bacteria Ch 2- The substance CaCO3 in water will contribute to the - Answer: total alkalinity and carbonate hardness Ch 2 - The chemical preservative normally used for water samples that are to be tested for metals is - Answer: HNO3 Ch 2 - The primary concern when a treated water exceed the MCL for turbidity is that - Answer: The turbidity may harbor pathogenic organisms preventing proper disinfection When must an operator be certified - Answer: within 10 days of employment or appointment as an operator An Operator is - Answer: a person who performs work on, or determines the method of working on, water works or who changes water quality either directly or by order. This includes a person who sets or removes meters, makes service connections, or repairs lines. Water Works - Answer: all facilities used in the procurement, treatment, storage, pumping, or distribution of water for human consumption. Superintendent - Answer: the operator in direct responsible charge of an entire plant or distribution system. This is true even if other official titles are sometimes assigned by employers Operator Certification Unit - Answer: (1500 or less = D) ( = C) ( = B) (>50000 = A) All surface water systems must be operated by a Superintendent with at least a class C certification for populations less than 15000 Public Water Supply Operation (Chap 631) - Answer: Regulations for actual operation of public water supply system. this includes sampling, monitoring, reporting, and public notice requirements for water supplies.Implemented by the Water Quality Division of ODEQ. Public Water Supply Construction Standard (Chap 626) - Answer: Standards for the construciotn or modification of the physical system of public water supply systems. This document is also implemented by the Water Quality Division of ODEQ Rules for Oklahoma Hazard Communication Standard - Answer: Rules regarding the transmission of necessary information to employees about the properties and potential hazards of hazardous substances in the workplace. Enforced by the Public Employees Health and Safety Division of the Oklahoma State Department of Labor. Monthly Operations Report (MOR) - Answer: A complete record of most of the major factors involved in plant operations for each day of the month. It is the Superintendent's responsibility to ensure MOR is kept up to date and accurate. Original MOR must be submitted by the 10th day of the following month to the DEQ Water Quality Division. A second copy must be kept at the facilityh for at least 10 years. Falsification of Records - Answer: Punishable by loss of certification, fine of up to 25,000 per violation and 1 year in jail. CH 3 - Records at water systems must be kept for - Answer: 10 years Ch 3 - The superintendent of a water system treating surface water for a community of 550 persons must hold at least - Answer: Class C certification Ch 3 - If the Utilities Director selects which chemicals and what must be used in the community water system, he or she - Answer: Must be certified at the same level required of the superintendent Ch 3 - Which of the following requirements is primarily concerned with keeping a permanent, unalterable record of laboratory data? - Answer: A bound volume must be kept for records of the test results, date, time, and signature of analyst. Nutrients - Answer: Nitrate, phosphate, and other compounds. They are often responsible for water quality problems associated with surface water supplies. Algae bloom - Answer: Sudden increase in algae populations in surface water sources. the most common water quality problems associated with surface water supply systems can be traced directly back to algal blooms. Quality Problems associated with Algae blooms - Answer: 1. taste and odor problems 2. Increased pH levels 3. Increase in organic loading 4. Dissolved oxygen depletion Copper Sulfate (CuSO4) Bluestone - Answer: Chemical used to control Algae growth in water sources. Ch 4 - A surface water source is usually (in terms of taste and odor) - Answer: lower quality water than ground water Ch 4 - The chemical sometimes used to control algae populations in surface water sources is - Answer: CuSO4 Ch 4 - What is the approximate volume of a reservois in gallons for a reservoir of 58 acre/ft? - Answer: 18.9MG (1 acre/ft = 325851, 325851*58=18,899,358) Ch 4 - How much CuSO4 is needed to dose a reservoir with 0.5mg/L if the reservoir volume is 20MG and the CuSO4 solution is 25% - Answer: 335 lbs (insert Math here) Acre/ft to gallons - Answer: 325,851 gallons Primary Coagulants - Answer: Primary coagulants cause the initial coagulation reaction to take place and cause the particles to begin clumping together. Coagulant Aids - Answer: added to form bigger flocs. Include pH adjusters, activated silica, clay, and polymers. Increases density and prevents shearing. Aluminum sulfate (alum) - Answer: Al2(SO4)3*14H2O is a common primary coagulant. Most effective between pH 5.0 and 7.0. Alum will consume 0.5mg/L of alkalinity for every 1.0mg/L of alum that is dissolved in water. Alkalinity is necessary for coagulation to occur. Alum tends to lower pH. Ferric Chloride - Answer: FeCl3*6H2O is a primary coagulant Ferric Sulfate - Answer: Fe2(SO4)3*9H2O a primary coagulant Ferrous Sulfate - Answer: FeSO4*7H2O a primary coagulant Lime - Answer: CaO used to increase alkalinity levels in water Hydrated Lime (calcium Hydroxide) - Answer: Ca(OH)2 used to increase alkalinity levels in water Soda Ash (Sodium Carbonate) - Answer: Na2CO3 Used to increase alkalinity levels in water Caustic soda (sodium hydroxide) - Answer: NaOH Used to increase alkalinity levels in water Sedimentation rate - Answer: The speed that a particle can move as it settles to the bottom of a clarifier Detention Time - Answer: The actual time required for a volume of water to pass through a basin. Short Circuiting - Answer: A condition that occurs in flocculation when some of the water in the basin travels faster due to temperature differences, density currents, wind currents or improper design of inlet and outlet structures. Secondary coagulation - Answer: This condition is a result of supersaturating the water with alum or other primary coagulants where some of the coagulant stays dissolved throughout the treatment process. It then produces Floc in the distribution system. Ch 5 - A commonly used coagulant in water treatment is - Answer: Aluminum Sulfate Ch 5 - The test performed at water plants to determine optimum dosage levels of coagulants and coagulant aids is - Answer: The jar test Ch 5 - A solids contact basin has a surface loading rate of 0.75 gpm/ft2. What is the rise feet in ft/min - Answer: 0.1 (1 gal = 0.133 ft3, 0.75gpm/ft2 * 0.133 ft3 = 0.0975 ft/min) A raw water has an alkalinity of 36 mg/l (as HCO3). A dose of 52 mg/l of alum is needed to reduce the turbidity from 75 NTU to lass than 0.5 NTU. At least 30 mg/l of alkalinity is requires for complete precipitation of alum. What dose of Ch(OH)2 is needed to complete the reaction? - Answer: 13.5 mg/l (insert math here) Adsorbtion - Answer: The gathering of a substance on the surface of the filtration media One gallon is how many cubic feet - Answer: 0.1337 ft3 Biological action - Answer: The breakdown of a substance as a result of digestion by microorganisms Absorption - Answer: Taking in or "soaking up" of a substance into themedia Straining - Answer: The removal of particles by passing the liquid through a filter that has pores small enough to "catch" the particles to be removed Simple Sedimentation - Answer: Particles settling onto the media through the forces of gravity Rapid Gravity Filtration - Answer: The most common type of filtration used in water treatment 1. Single Media (Sand) 2. Dual Media (anthracite coal and sand) 3. Multimedia (anthracite coal, sand, and garnet) Activated carbon - Answer: A form of specially treated, porous carbon, used to remove various odors and tastes as well as various types of organic substances. Filter Breakthrough - Answer: Turbidity will build up on the surface and inside the media of the filter eventually causing clogging of the filter. This leads to breakthrough, a condition in which solids are no longer being removed. Filter Run - Answer: The period of time between back washing. Surface Wash - Answer: A device that is activated sometime during the backwash procedure that sprays water down onto the surface of the filter to break up solids that have collected. Backwash schedule - Answer: It is a good practice to always backwash the filter every 72 hours of operation, even if significant head loss has not yet developed. Head Loss - Answer: Clogging of a filter can be defined as a build-up of head loss (pressure-drop) across the filter media. Design limits for head loss generally range from about 6 to 10 feet depending mainly on the depth of the water over the media. Backwash flow Rates - Answer: Most filters utilize backwash flow rates of about 20 gpm/ft2 or other rates necessary to provide for 50% expansion of filter media. Typical water plant will use approximately 2 to 4 percent of the water produced as the plant for backwashing purposes. Filter Rate - Answer: The rate that water flows through the media and is expressed in gpm per square foot (gpm/ft2) Mudballs - Answer: Pockets of sludge and other solids that build up in the filtration media Air Binding - Answer: A situation where air enters the filter media as a result of differences in pressure between water and the pressure in the filter. Dissolved air is released from saturated cold water due to the decrease in pressure in the filter. Air binding can prevent the passage of water during the filtration process and can cause a loss of media during the backwash process. Granular activated carbon (GAC) - Answer: Sometimes utilized as an activated carbon filtration media for removing taste and oder compounds in water. It is also used for removing volatile organic compouncs (VOCs) and synthetic organic compounds (SOCs). Becomes "spent" over time and will need replaces or "reactivation" Ch 6 - The most common type of filter used by water plants in Oklahoma is the - Answer: rapid gravity sand filter Ch 6 - The most important removal process that takes place during filtration is - Answer: Sedimentation Ch 6 - The most important filter effluent water quality change is - Answer: Turbidity Ch 6 - A plant filter 2.2 MGD with a filter surface of 600 ft2. What is the filtrate rate in gpm/ft2 - Answer: Disinfection - Answer: The destruction of most of the pathogenic organisms present in the water Sterilization - Answer: The complete destruction of all organisms present in the water. Calcium Hypochlorite (High Test Hypochlorite (HTH)) - Answer: Calcium hypochlorite Ca(OCl)2 is a disinfectant that can be purchased in tablet, powder or granulated form. HTH has about 65% available chlorine Sodium hypochlorite (Liquid Bleach) - Answer: Sodium hypochlorite NaOCl is a disinfectant that comes in liquid form. Common household bleach has a concentration around 5.25%. Most water systems that use bleach will use a 10 to 15% concentration. Hypochlorous acid (HOCl) - Answer: A weak acid formed from water and chlorine gas (Cl2) that has good disinfectant properties Hydrochloric acid (HCl) - Answer: A strong acid that is formed from water and chlorine gas (Cl2) that has weak disinfectant properties. Most common source of chlorine gas leaks - Answer: Reusing gaskets and washers on chlorine cylinders. How to detect a chlorine gas leak - Answer: Ammonia vapors can be used as a simple method of chlorine leak detection. Where are exhaust fans placed in chlorine storage areas - Answer: near the floor. Chlorine gas is 2.5 times heavier than air. Exhaust fans must provide at least one complete air change per minute whenever the chlorine room is occupied. Where must SCBA equipment be placed - Answer: Self Contained breathing apparatus SCBA must be placed in a convenient location but NEVER in side the chlorine room. SCBA should be compatible with those of the local fire department. Fit testing while wearing a SCBA should be done to ensure a leak-proof seal. Facial hair may prevent an effective seal. Persons wearing a SCBA must perform a questionnaire and possibly a medical examination first. Buddy System - Answer: System where two people are required before work on or around a chlorine system for safety. Buddy must watch the work being done from a safe position. HTH Storage - Answer: Should be kept in a dry place away from any source of organic matter including dirt, oils, or dirty rags. Chlorine Dose - Answer: Chlorine Dose = Chlorine Demand + Chlorine Residual Chlorine Residual - Answer: Chlorine Residual = Combined Chlorine Residual + Free Chlorine Residual Chloramines - Answer: Chlorine that has reacted with ammonia. Often referred to as "combined residual". When using chlorimines as a disinfecting agent, a chlorination technique called "breakpoint Chlorination" must be utilized. Breakpoint Chlorination - Answer: Addition of chlorine to water until the chlorine demand has been satisfied. At this point, further additions of chlorine will result in a free residual chlorine that is directly proportional to the amount of chlorine added beyond the breakpoint. DPD Method - Answer: A method of measuring the chlorine residual in water. The residual may be determined by either titrating or comparing a developed color with color standards. DPD stands for N,N-diethyl-p-phenylenediamine. Chlorine residual requirements (chlorine systems) - Answer: Minimum 1.0 mg/L entering distribution system Minimum 0.2 mg/L throughout the distribution system Chlorine residual requirements (chloramine systems) - Answer: Minimum 2.0 mg/L entering distribution system Minimum 1.0 mg/L throughout the distribution system Chlorine gas with water reaction - Answer: Produces Hypochlrous acid (HOCl) and Hydrochloric acid (HCl) Calcium Hypochlorite (HTH) with water reaction - Answer: Produces Hypochlorous acid (HOCl) and Calcium hydroxide (Ca(OH02)) Sodium Hypochlorite (bleach) with water reaction - Answer: Produces Hypochlorous acid (HOCl) and Sodium hydroxide (NaOH) Ammonia (NH3) with Hypochlorous Acid (HOCl) reaction - Answer: Depends on pH level pH between 6.5 - 8.5 monochromine (NH2Cl) is formed Prechlorination - Answer: The addition of chlorine at the headworks of the plant prior to other treatment processes mainly for disinfection and control of tastes, odors, and aquatic growths. Also applied to aid in coagulation and settling. Increases THMs Methods of THM control - Answer: Remove the precursors (oxidation and adsorption) Aeration to remove THMs from water Turbidity levels - Answer: Less than or equal to 0.3 NTU for 95% of measurements taken. MCL is 1 NTU. If the Combined Filter Effulent (CFE) turbidity excees 1 NTU at any time, the DEQ must be notified within 24 Hours. Continuous monitoring of each filter every 15 minutes. Ch 7 - The chlorine that remains after chlorine demand has been satisfied is called the - Answer: Chlorine residual Ch 7 - The chemical that is mainly responsible for the disinfectant properties of chlorine is - Answer: HOCl Ch 7 - Estimate the chlorine demand if the dose is 3 mg/L and the total chlorine is 0.5 mg/l after 30 minute contact time. - Answer: 2.5 mg/L (Chlorine Dose = Chlorine Demand + Chlorine Residual) Ch 7 - A flow of 400 gpm is treated by a hypochlorinator which has a pumping rate of 6 gpd using a 2% solution of available chlorine. What is the chlorine dosage in mg/l? - Answer: What is the main cause of lead and copper contamination in drinking water? - Answer: Corrosive water. Most problems are household plumbing leaching copper and lead solder. What is "Stable" Water - Answer: Water that is just saturated with Calcium Carbonate (CaCO3) so that it will neither be corrosive or leave a deposite of calcium carbonate "scaling". Tuberculation - Answer: Caused by internal pipe corrosion and/or a build-up of rust. Tuberculation cannot be detected without an internal inspection. Build-ups in the valve may be an indication that the same is happening within the pipes. Such a build-up can significantly change the volume of water delivered by a system. Marble test (Calcium Carbonate Stability Test) - Answer: Test used to measure the "Stability" of water. Determines the saturation level of calcium carbonate (CaCO3) Treatment for corrosive water - Answer: Treated with chemicals so that the water is saturated or slightly supersaturated with Calcium Carbonate (CaCO3). For water with low hardness and low alkalinity: Quicklime - Calcium Oxide (CaO) "Slaked" Lime - Calcium Hydroxide (Ca(OH)2) For water with high hardness and high alkalinity and when pH levels need to rise: Caustic Soda - Sodium Hydroxide (NaOH) Soda Ash - Sodium Carbonate (Na2CO3) Indexes used to determine chemical dosage to change pH and produce calcium carbonate saturation - Answer: Langelier Index Driving Force Index Aggressive Index Most common complaint about water quality - Answer: Taste and Odor along with "colored water" Causes of Taste and Odor problems - Answer: Micro organisms produce "metabolic by-products" and cellular material are released into water when they die. Low dissolved oxygen levels (caused by increased nutrient levels or increased algae activity). Anaerobic micro capable of producing Hydrogen Sulfide (H2S). Man-made causes from poor municipal treatment, industrial wastewater, or poor surface water. Consumers plumbing system Taste and Oder Treatments - Answer: "Degasification" to remove dissolved gases from water "Adsorption" by adding chemicals to the treatment process that attract odor producing compounds "Chemical oxidation" to destroy taste and odors instead of removing them. Chrenothrix or Iron Bacteria - Answer: Caused by high concentration of Iron and Manganese and form thick slimes on inter walls of well casings and distribution lines (reddish brown or black in color depending on whether iron or manganese is dominant) Treatment of Iron and Manganese - Answer: if water contains no more than 0.3 mg/L Manganese and 0.1 mg/L iron then "Polyphosphate" can be used. It is a sequestering agent that keeps the iron and manganese from precipitating for a few days. Chlorine should be fed along with polyphosphate to eliminate chrenothrix or iron bacteria. Chlorine should NEVER be fed ahead of polyphosphate because it will cause the iron and manganese to precipitate. Phosphate dosage max of 10 mg/L Oxidation by Aeration is another treatment Oxidation by chlorination Oxidation with Pottasium Permanganate (KMnO4) Water softening Fluoride Concentration in water - Answer: Floride reduces cavaties up to 60% among children who ingest from birth. 0.8 mg/L to 1.3 mg/L with exactly 1.0 mg/L as optimum Dental Fluorosis (Motted teeth) - Answer: Occurs when fluoride levels in excess of 1.5 mg/L are consumed for extended periods of time. Water Softening Methods - Answer: Ion Exchange is rarely used by municipal water systems because of costs. Chemical Precipitation: Lime softening (Ca(OH)2) to the saturation point for carbonate hardness Lime-Soda Ash Softening (Na2CO3) plus (Ca(OH)2) for when removing noncarbonate hardness is necessary. Recarbonation for lime-soda ash soften to lower pH. This is done by adding carbon dioxide (CO2). This makes a more stable water and less scaling. Ch 8 - Soften is done to remove - Answer: Hardness Ch 8 - The optimum concentration of fluoride in public water supplies has been determined to be - Answer: 1.0 mg/L Ch 8 - One ml of standard polyphosphate solution (0.1%) in a liter sample is equal to - Answer: 1 mg/L (10,000ppm = 1 mg/L so x=10,000 * 0.1 * 1/1000) Ch 8 - Estimate the percent recover of a reverse osmosis unit with 4-2-1 arrangement if the feed flow is 5.88 MGD and the effluent flow is 5.0 MGD - Answer: 85% (effluent/feed flow *100)