North Carolina Water Operator B Certification Practice Exam

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• What type of corrosion is caused by the use of dissimilar metals?
• Which of these parameters is NOT directly related to the removal/inactivation of pathogens?
• What does static head refer to in a water system?
• Which of the following is a type of liquid level sensor?
• What is the purpose of wearing rings in a pump?
• When filling tankers with toxic chemicals, what precaution should be taken regarding backflow prevention?
• What do MCLs primarily relate to?
• What is an essential aspect of a good preventative maintenance program?
• Which of the following is included in free residual chlorine?
• Which of the following is NOT a characteristic of coliform bacteria?
• What should be the minimum size of fire hydrants on water mains?
• Which type of public water supply includes locations where people live for six months or less?
• In colorimetric analysis, what does a darker color indicate?
• What effect can excessive dissolved oxygen have?
• What is indicated by the presence of polyphosphates in water treatment?
• What is the secondary maximum contaminant level (SMCL) for fluoride in water?
• What type of hazard is primarily associated with health risks in public water systems?
• What does the term 'supernatant' refer to in a water treatment context?
• What is the typical phosphate used for corrosion control in water systems?
• When must violations of inorganic compounds and VOC detection be reported?
• What is typically the first sign of a problem with a pump?
• What does the acronym NTU stand for in water quality measurement?
• Which factor has the greatest influence on chlorine effectiveness?
• After how many hours should the first draw samples for Lead and Copper analysis be collected?
• What does chlorine demand represent?
• What is a notable property of sodium fluoride in powdered form?
• What is the basic unit for electrical power?
• What type of contaminants do secondary maximum contaminant levels (SMCLs) relate to?
• Corrosion inhibitors function primarily by:
• Which disease can be transferred through contaminated water?
• At what temperature do fusible plugs melt?
• Which type of Positive Displacement pump is commonly used?
• What is the MCL for HAA5?
• What happens to some acids when they are opened?
• What is the recommended time duration for conducting jar testing effectively?
• What is the significance of jar testing in a water treatment process?
• What is the continuous exchange of water between the earth and the atmosphere called?
• Which metal is most susceptible to galvanic corrosion?
• During the daytime, which process takes place that increases pH levels in the water?
• What is the MCL goal?
• How often must sampling be conducted if volatile organic compounds (VOCs) are detected?
• What is the initial filtration step for efficiently treating water containing Cryptosporidium?
• What is the minimum air gap needed when filling tankers from a public water system?
• Which type of pumps cannot pump against a closed valve?
• What is the maximum time frame required for public notification of a Tier 1 violation?
• Which of the following is the most reliable method for ensuring water safety from Cryptosporidium?
• What is the main effect of acids on metals?
• What safety equipment is required for permit-required confined space entry?
• What is the primary function of sand filters?
• If the pump bearings on horizontal centrifugal pumps are over lubricated, what may occur?
• What concentration of fluoride is associated with a minimum degree of fluorosis?
• How often should jar testing be conducted according to best practices?
• What maintenance is critical to ensure a pump operates efficiently?
• In the multiple tube fermentation test, what are the two tests performed?
• One use of polyphosphates is to?
• How can the formation of mud balls in a filter be prevented?
• What is the minimum pressure required in a water distribution system during peak flow?
• What is the optimum velocity for flocculation?
• What could cause excessive vibration in a motor-pump system?
• What is the consequence of high levels of dissolved oxygen in water systems?
• Which contaminant's MCL is set at 0.015 ppm in drinking water?
• How does hydrofluosilicic acid behave regarding temperature?
• Which solubility characteristic is associated with ferrous iron?
• How often should a sealed ball bearing in an electrical motor be lubricated?
• What is the AFI purity level of hydrofluosilicic acid?
• How long must chlorine remain in disinfecting tanks before being flushed out?
• Which type of pump is commonly associated with high inlet flow rates?
• According to the lead and copper rule, how often must 7% of pipes be replaced?
• Why are vacuum trucks preferred for removing sludge?
• What pH would chlorinated water have the highest concentration of hypochlorous acid?
• How does temperature impact the pressure of a chlorine cylinder during use?
• What tool can be used to check proper alignment between two shafts?
• What is the maximum withdrawal rate for a 150 lb chlorine cylinder?
• Coagulation in the water treatment process occurs in what time frame?
• Why is it crucial to monitor water sources for Cryptosporidium?
• What should be the separation distance when water under a sewer is constructed with ferrous materials?
• Which of the following methods is ineffective for treating Cryptosporidium?
• What is the function of a stuffing box in a pump?
• What is the action level for lead in drinking water?
• Which method is considered acceptable for controlling corrosion in water systems?
• What is the recommended dosage of fluoride to prevent dental issues?
• Chlorine gas is how much denser than air?
• Methyl orange is used to test for which of the following?
• What is the definition of an inhibitor in the context of water treatment?
• What is the effect of feeding lime to water for corrosion control?
• Which chemical has a purity of 0.98 and is known for its higher solubility with higher temperature?
• How many volumes of chlorine gas can be yielded from liquid chlorine under pressure?
• When is a violation of the MCL for TTHMs considered to occur?
• What function do flexible couplings serve when connecting the motor and the pump shaft?
• What is the purpose of jar tests in water treatment?
• How is the settling basin best described?
• What is the effect of piping two pumps with the same flow capacity and pressure rating in series?
• What effect does hydrogen sulfide gas have on structures and equipment?
• What are the two main categories of taste and odor treatment methods?
• Which of the following is a potential issue caused by manganese in water systems?
• What is the required minimum daily average supply from combined elevated and ground storage tanks?
• What type of corrosion occurs primarily due to high velocity in copper pipes?
• What is the operator responsible control (ORC) requirement during operation?
• Which type of pump is characterized as a Variable Displacement pump?
• Which valve is most suitable for a throttling application?
• What color transition indicates a successful titration for chloride?
• When is it critical to inspect pump bearings?
• What is the relationship between pH and the formation of disinfection byproducts?
• Which of the following is NOT a filtration mechanism?
• What is a common characteristic of vertical turbine pumps?
• What is the action level for copper in drinking water?
• How long does sedimentation typically take in water treatment?
• What device is used to reduce voltage?
• What can occur if water is used to control a chlorine gas leak from the disinfection assembly?
• What role does pH play in corrosion control?
• What does screw chlorine refer to in the context of Cryptosporidium treatment?
• Which of the following is a common fluoridation chemical?
• What is the deadline for reporting violations for microbiological MCLs to the state?
• Which of the following is a requirement for all public water systems under the Safe Water Drinking Act?
• Which of the following is a potential hazard when using chlorine gas?
• How long must a public water system wait to notify consumers about a Tier 3 violation?
• When must all routine coliform test results be reported to the state?
• What is the product formed when chlorine is combined with nitrogenous compounds?
• What should be prioritized when considering water treatment for Cryptosporidium?
• How is total chlorine calculated?
• What is the consequence of water being very hard (greater than 10.5 gpg)?
• What happens to pH levels during nighttime respiration by algae?
• What is the primary use of vinegar in water treatment?
• What chemical is commonly used to control algae in reservoirs?
• What is the primary cause of most pump problems?
• How often must combined filter effluent turbidity be measured?
• What percentage indicates an oxygen deficient atmosphere?
• What form of iron is most soluble in water?
• Which method is hinted to be less reliable compared to filtration for Cryptosporidium removal?
• What do the colors indicate during a titration for alkalinity?
• What is the MCL for chlorite in public water systems?
• How is disinfection byproducts compliance calculated?
• What is the formula to convert Fahrenheit to Celsius?
• What is the main purpose of monitoring coliform in public water systems?
• Which of the following represents a non-transient non-community water supply?
• What major factor contributes to reservoir turnover?
• What is the primary purpose of monitoring pH levels in water treatment?
• What is breakpoint chlorination?
• How quickly can coliform bacteria ferment lactose to produce gas in appropriate conditions?
• What does 'head' refer to in the context of pumping?
• What can cause scaling in water systems that use saturators?
• What is the optimum size for floc particles?
• What method is commonly used to soften water?
• How long does flocculation typically take to occur?
• What causes air binding in filtration systems?
• What is the purpose of taking composite samples?
• What happens when a discharge valve is closed at a station with centrifugal pumps?
• What might happen if a pump operates at a significantly higher flow rate than intended?
• In the context of toxins, what is an example of a type of chemical that may require specific backflow prevention measures?
• Which major maintenance task typically occurs at a water plant?
• What is the effectiveness of chlorine in removing Cryptosporidium?
• What occurs in water at 39.2 degrees Fahrenheit?
• What is the primary function of floats in liquid level sensing?
• Which of the following is NOT a method of corrosion control?
• How many repeat samples must be taken within 24 hours if a routine coliform sample is positive?
• In the context of drinking water regulation, what does "action level" refer to?
• What is the action level for the 90th percentile lead level in drinking water?
• Normality refers to what?
• What is the primary method for removing Cryptosporidium from water?
• In the context of water operations, what does TD/TC refer to?
• What happens to iron and manganese forms when oxygen is present?
• What is the minimum capacity a hydropneumatic storage tank must provide for fire demand?
• What can occur if the back pressure on a pump drops too low for a prolonged period?
• What causes the metal strip in an electrical fuse to melt?
• What color does chloride indicator change from during titration?
• If a fuse continues to blow, what should you do first?
• Which compound is commonly used as a typical coagulant in water treatment?
• What is the Maximum Contaminant Level (MCL) for total trihalomethanes?
• What is the primary method to lower pH in water treatment?
• Which process involves the gathering of substances on a surface in filtration mechanisms?
• A public water system must serve how many service connections to be regulated under Safe Drinking Water Act?
• What component of a pump connects the motor to the impeller?
• What is the minimum pressure required in systems designed for fire protection?
• Which of the following is a common pH increasing chemical?
• What is the MCL for nitrate in drinking water?
• Which method should be used when working on chlorinators?
• What is the AFI purity level of sodium fluoride?
• What is a potential consequence of inadequate sludge disposal methods?
• What occurs at a pH level of 5 in chlorinated water?
• What happens when chlorine dosage is increased during chlorination?
• What turbidity level is considered acceptable in terms of MCL?
• What does a chlorine residual measure represent?
• What characteristic of septic systems is primarily noted?
• What is the primary role of fusible plugs in chlorine cylinders?
• What testing method is recommended to monitor water quality changes?
• What does BGB refer to in a coliform testing context?
• What could be a consequence of a poorly installed mechanical seal?
• Apparent color includes which substances?
• How often must water quality reports be submitted to public water systems?
• What is the settling rate of particles in water affected by?
• What is used in large hydrofluosilicic acid systems for feeding?
• Which part of a pump is commonly referred to as the eye?
• What is the MCL for lead in drinking water?
• What requirement does the Safe Water Drinking Act impose on public water systems regarding bacteria?
• When is softened water required for the use of saturators?
• Manganese can result in which of the following?
• What is the MCL for bromate?
• What impact does corrosion have on water supply systems?
• In what situations should jar testing be conducted according to industry standards?
• From where must all public water systems initially collect samples to monitor lead content?
• Which indicator color change indicates the presence of calcium in water?
• What is the maximum contaminant level (MCL) for fluoride in water?
• What is the maximum contaminant level (MCL) for turbidity in drinking water?
• Which chemicals cause alkalinity in water?
• How many individuals must a public water system serve to be subject to regulations?
• What are combined residual chlorine compounds?
• What aspects does the performance curve of a pump reflect?
• What is the maximum length for a 2-inch water main serving residential connections?
• Which method is NOT commonly used for sludge disposal?
• What is the primary purpose of presedimentation in water treatment?
• Total hardness of water refers to which of the following?
• Which of the following is true regarding monitoring schedules for contaminants?
• What is the minimum chlorine residual requirement in water systems?
• What is the defining characteristic of a settling zone in a settling basin?
• What is the required depth for burying water mains to protect against frost?
• Which device is primarily used for adjusting electrical power?
• What must the two components of a mechanical seal for a pump do?
• What is the main purpose of the National Pollutant Discharge Elimination System?
• What happens when you use hard water in systems utilizing saturators?
• What pH level indicates that treated water may be corrosive?
• What will happen to the pressure indicator on a chlorine cylinder with steady temperature until all chlorine has been gasified?
• What type of substances do combined residual chloramines interact with?
• What characteristics define coliform bacteria?
• What does a single-phase motor indicate?
• What percentage accuracy is required for feeding equipment in water treatment systems?
• In a chlorinator, a vacuum is formed primarily by what process?
• What is a foot valve's function in a centrifugal pump system?
• What issues can algae in a reservoir cause?
• Which type of chlorine is most commonly used in water disinfection processes?
• What is the maximum contaminant level (MCL) goal for known or probable carcinogens?
• What device is used to control the feed rate of chlorine gas in a treatment plant?
• What treatment technology can be implemented to comply with a volatile organic chemical MCL?
• What is the purity of sodium silicofluoride?
• What type of sample is taken at a specific point in time?
• What is a primary use of colorimetric analysis in water quality testing?
• What is the principal cause of corrosion of metals in water?
• What is a tubercle in the context of water corrosion?
• Which chemical is used to increase pH levels in water treatment?
• Under what conditions is steel most likely to corrode?
• According to the hardness scale, which range is considered slightly hard?
• Which Safe Water Drinking Act (SWDA) establishes action levels rather than MCLs?
• What indicates a low chlorine demand in water treatment?
• What type of fluoride saturator operates based on gravity?
• What is essential for effective chlorine disinfection?
• What is the maximum number of residents allowed on a 2-inch diameter water main?
• How does activated carbon combat taste and odors in water treatment?
• Which class of fire involves electrical equipment?
• In disinfection contexts, which byproduct is commonly monitored for health concerns?
• How does chlorine residual relate to pH levels?
• Which type of water treatment method focuses on removing particulates?
• Which method is used to measure chlorine residual in water treatment?
• When testing a 110 VAC outlet with a pocket VOM, to what range should you set it?
• What operation should be done to an entire filter during disinfection?
• If a centrifugal pump is vibrating excessively after start-up, what should be done?
• What does SCADA stand for in water management?
• What is true color defined as?
• What is one of the main goals of the sludge management process?
• What percentage of removal/inactivation does 4-log removal represent?