Water Treatment Grade 1 Flashcards
Which group of bacteria are the ideal indicator for pathogens?
1. Salmonella Species
2. Coliform group bacteria
3. Gram-negative cocci
4. Gram-negative coccobacilli
- Coliform group bacteria
Acids, bases, and salts lacking carbon are
1. ketones.
2. aldehydes.
3. organic compounds.
4. inorganic compounds.
- inorganic compounds.
The organisms used to indicate the likelihood that pathogenic bacteria may be present are
1. Salmonella bacteria.
2. enteric viruses.
3. coliform bacteria.
4. Pseudomonas group bacteria.
- coliform bacteria.
A physical property, as opposed to a chemical property, that is important to remove by water treatment is
1. turbidity.
2. pH.
3. dissolved solids.
4. electrical conductivity.
- turbidity.
What are the two principal chemicals that cause water hardness?
Calcium and Magnesium
Viruses CAN or CANNOT survive in the environment for any length of time outside of a human’s or animal’s body?
They Cannot
What is the smallest particle that retains the characteristics of the element that it helps form?
Atom
A group of elements that bond together and act like single atoms or ions in forming compounds are known as what?
a Radical
What measurements are used to express the weight of a solute dissolved in a given volume of solution?
Milligrams per Liter (mg/L)
Grains per Gallon (gpg)
1 Gallon of Water = How many Pounds?
8.34 Pounds
What is the formula for the Area of a Circular Tank (ft3)?
3.14 x (radius x radius) = ft3
How do you find the Radius of a Circle?
Diameter/2 = Radius
What is a linear measurement?
A linear measurement defines the distance along a straight line; it is measured between two points.
Provisions under which regulation are intended to protect drinking water consumers from the unintended public health consequences associated with the consumption of treated drinking water containing residual disinfectants & disinfection by-products?
1. Filter Backwash Rule
2. Ground Water Rule
3. Disinfectants and Disinfection By-Products Rule
4. Surface Water Treatment Rule
- Disinfection and Disinfection By-Products Rule
Under the Sage 1 DBPR, the compliance value for TTHM’s & HAA5’s is determined by calculating a _____ during the previous 12 months for each DBP for all monitoring locations at each plant.
1. running annual average
2. maximum contaminant level
3. locational annual average
4. C x T value
- running annual average (RAA)
What is the MCL for Nitrate?
10 mg/L
What is the MCL for Nitrite?
1 mg/L
What is the MCL for Fluoride?
4.0 mg/L
What is the MCL for TTHM’s?
80 ug/L (ppb)
What is the MCL for HAA5’s?
60 ug/L (ppb)
What is the MCL for Arsenic?
10 ug/L (ppb)
What is the treatment technique for Copper?
Action Level = 1.3 mg/L (ppm)
What is the treatment technique for Lead?
Action Level = 15 ug/L (ppb)
What is a Sanitary Survey?
It is an assessment of the water supply system and its capability to produce safe water.
How does the SDWA define a Public Water System?
A supply of piped water for human consumption that has at least 15 service connections, or serves 25 or more people 60 or more days a year.
The movement of water from leaves, grasses, & other plants to the atmosphere is called
1. organic evaporation.
2. condensation.
3. transpiration.
4. capillary action.
- transpiration.
A term used to describe cloud formation is
1. transpiration.
2. evaporation.
3. condensation.
4. precipitation.
- condensation.
An artesian aquifer could form in a(n)
1. confined aquifer.
2. unconfined aquifer.
3. water table aquifer.
4. shale formation.
- confined aquifer.
The process whereby water moves with the air currents in the atmosphere is called
1. transpiration.
2. evaporation.
3. interception.
4. advection.
- advection.
The place where groundwater accumulates is called a(n)
1. ground source.
2. water table.
3. channel.
4. aquifer.
- aquifer.
Drinking water that is aesthetically acceptable is considered
1. palatable.
2. sterile.
3. potable.
4. harmless.
- palatable.
Providing several treatment processes that can each remove a water contaminant is an example of what?
The multi-barrier approach to water treatment
Which function of the hydrologic cycle is described as water moving with air currents in the atmosphere?
Advection
Which function of the hydrologic cycle is described as water that has collected as snow or ice being released as a liquid?
Snowmelt
The most frequent in-situ well treatment is the application of a(n)
1. chemical to adjust the pH of well water that is either too acidic or too alkaline.
2. phosphate inhibitor to prevent well corrosion.
3. oxidant to reduce iron bacteria.
4. coagulant for high-turbidity well water.
- oxidant to reduce iron bacteria
What type of disinfectant is usually used to disinfect the gravel packing of a groundwater well?
1. Chlorine dioxide
2. Powder of calcium hypochlorite tablet
3. Sodium hypochlorite
4. Chloramines
- Powder of calcium hypochlorite tablet
Which of the following is the most common well operational problem?
1. Plugging of the pump with sediment
2. Pump failure
3. Plugging of the well screen
4. Corrosion of the well’s metal parts
- Plugging of the well screen
What is the last step in well construction?
1. Placement of the well seal
2. Disinfection
3. Installation of the pump
4. Pump test to confirm capacity
- Pump test to confirm capacity
What gas occurs mainly in groundwater, is heavier than air, and is odoriferous?
1. Hydrogen sulfide
2. Carbon dioxide
3. Radon
4. Methane
- Hydrogen sulfide
Disinfection of water wells with free chlorine requires exposure for _____ at a concentration of _____?
1. 6 - 12 hours; 25 mg/L
2. 12 - 24 hours; 25 mg/L
3. 12 - 24 hours; 50 mg/L
4. 24 - 48 hours; 100 mg/L
- 12 - 24 hours; 50 mg/L
At what free chlorine concentration should a well be disinfected at?
50 mg/L (ppm)
What water quality problems are most prevalent in groundwater?
Hard water, high iron content, potential for radon, hydrogen sulfide from anerobic conditions
What is the term for the level of the water surface in a well when no water is being pumped?
Static water level
What term refers to the rate of water withdrawal that a well can supply over a long period of time?
Well yield
Which type of wells are commonly used near the shore of a lake or near a river to obtain a large amount of relatively good-quality water from adjacent sand or gravel beds?
Radial wells
Where land is _____, runoff tends to spread out and soak into the ground more easily.
1. steep
2. fairly flat
3. V-shaped
4. hilly
- fairly flat
Streams that flow only occasionally, usually only during and shortly after a rain are called
1. intermittent streams.
2. perennial streams.
3. natural streams.
4. ephemeral streams.
- ephemeral streams.
What are the main causes of algal blooms?
Increased nutrients, ideal temperature, plentiful sunlight, and specific algae types
Which of the following plants grow in shallow water on or near the shoreline, rooting the bottom mud & sometimes extending well above the water surface?
1. Submerged plants
2. Emergent plants
3. Amphibious plants
4. Floating plants
- Emergent plants
What are the concerns when using a direct river intake for the water supply to a drinking water treatment plant?
Rapid changes in water quality from natural & human activity
What are the most common methods of algae control in lakes and reservoirs?
Copper sulfate & Potassium permanganate
What are the water quality problems caused by impoundment stratification?
Tastes & odors, iron & manganese
What are some invasive species in source water that require monitoring & treatment?
Zebra mussels & rooted aquatic vegetation
What type of intake is usually located next to a lake or river where it can pick up seepage from the surrounding sediment?
Infiltration gallery
Which of the following is a principal problem associated with preliminary pretreatment screening?
1. Broken screens
2. Excessive downtime due to numerous shear pins being broken
3. Clogging
4. Chain comes out of foot sprocket
- Clogging
Bar screen assemblies are installed in a waterway at a(n) _____ angle from horizontal.
1. 40 to 60 degrees
2. 60 to 80 degrees
3. 80 to 90 degrees
4. 90 to 120 degrees
- 60 to 80 degrees
Which of the following is NOT a term used to rank the distance between the bars in a bar screen?
1. Fine
2. Medium
3. Course
4. Wide
- Wide
_____ is a pretreatment process used to remove gravel, sand, & silt from the water before it enters the main treatment facility.
1. Screening
2. Pre-sedimentation
3. Preoxidation
4. Microstraining
- Pre-sedimentation
What is the first pretreatment provided in most surface water treatment systems?
Screening
A very fine screen primarily used to remove algae, other aquatic organisms, and small debris that can clog treatment plant filters is called what?
A microstrainer
What is the opening size for medium-ranked fixed screens or bar screens?
1/2 to 1 inches
Detention time in flocculation basins are usually designed to provide for how many minutes?
1. 5 to 15 minutes.
2. 15 to 45 minutes.
3. 45 to 60 minutes.
4. 60 to 90 minutes.
- 15 to 45 minutes.
Alum works best in the pH range of
1. less than 4.0.
2. 4.0 to 5.5.
3. 5.8 to 7.5.
4. greater than 9.0.
- 5.8 to 7.5.
Which natural electrical force keeps colloidal particles apart in the water treatment process?
Zeta potential
The zeta potential measures the number of excess _____ found on the surface of all particulate matter?
1. electrons
2. ions
3. cations
4. protons
- electrons
True/False
Colloidal particles are so small that gravity has little effect on them.
True
Particles held in suspension by the natural action of flowing water are called
1. settable solids.
2. sludge.
3. suspended solids.
4. dissolved solids.
- suspended solids.
In conventional water treatment plants, most flocculation basins are designed for
1. immediate flocculation.
2. tapered flocculation.
3. intermittent flocculation.
4. rapidly accelerating flocculation.
- tapered flocculation.
What is the attraction that exists between all particles in nature and tends to pull any two particles together called?
van der Waals force
Used in proper dosage, what are the effects of activated silica?
- It will increase the rate of coagulation
- It will reduce the coagulant dose needed
- It will widen the pH range for effective coagulation
What are some key virtues of mechanical mixers?
- They cost less than a conventional rapid-mixing installation
- The provide good instantaneous mixing with little short-circuiting
- The allow for adjustment to provide the correct amount of mixing energy
Which device collects the settled water as it leaves the sedimentation basin?
1. Effluent weir
2. Effluent flow box
3. Effluent baffle
4. Effluent launder
- Effluent launder
In solids-contact basins with fairly constant water quality parameters, how often should the solids concentration be determined?
1. At least once per week
2. At least every other day
3. At least once per month
4. At least twice per day
- At least twice per day
To draw off the liquid from a vessel of any size without stirring up the bottom sediment is known as what process?
Decanting
How often should sedimentation basins with mechanical sludge removal equipment be drained and inspected?
1. Twice a year
2. Once a year
3. Every other year
4. Every 3 years
- Once a year
What is the most important reason to reduce turbidity?
1. To reduce taste-and-odor problems
2. To remove pathogens
3. To reduce corrosion
4. To determine the efficiency of coagulation and filtration
- To remove pathogens
The sedimentation process is also known as what?
Clarification
Which area of the basin is designed to provide the calm (quiescent) area necessary for the suspended material to settle?
The settling zone
Which area of the basin is designed to receive the settled solids and keep them separated from other particles in the settling zone?
The sludge zone
In shallow-depth settling units, at what angle must modules be slanted at to be self-cleaning?
At an angle Greater than 50 to 60 degrees
As solids settle to the bottom of a sedimentation basin, a layer of WHAT develops?
Sludge
When a filter is ripening,
1. it is in need of a backwash.
2. turbidity is just starting to break through.
3. it is becoming more efficient in particle removal.
4. it is beginning to grow algae in the filter bed, walls, and troughs.
- it is becoming more efficient in particle removal.
Virgin greensand can be regenerated by soaking the filter bed for several hours in a solution of chlorine containing
1. 50 mg/L Cl2.
2. 75 mg/L Cl2.
3. 100 mg/L Cl2.
4. 200 mg/L Cl2.
- 100 mg/L Cl2.
Which role does the action of straining of suspended particles play during filtration?
1. Minor
2. Fair
3. Good
4. Major
- Minor
The turbidity of settled water before it is applied to the filters (post-sedimentation process) should always be kept below
1. 1 to 2 ntu.
2. 2 to 4 ntu.
3. 5 ntu.
4. 8 to 10 ntu.
- 1 to 2 ntu.
The combined process of mixing, flocculation, sedimentation, and filtration are commonly called
1. gravity filtration.
2. minimum treatment.
3. direct filtration.
4. conventional treatment.
- conventional treatment.
Performance goals are set forth by which regulation?
The Interim Enhanced Surface Water Rule (IESWR)
In water treatment plants using direct filtration, which step of conventional treatment is not included?
Sedimentation
What term refers to small, prefabricated treatment units that have been designed and assembled at a factory and then shipped to the installation site?
Package treatment plants
What are some advantages of slow sand filters?
- Low operating costs
- Low construction costs
- Low maintenance costs
The two most important factors impacting the effectiveness of chlorination are
1. the pH of the water and the content of foreign substances in the water.
2. the concentration of chlorine and the content of the foreign substances in the water.
3. the concentration of the chlorine and the contact time.
4. the pH and the temperature of the water.
- the concentration of the chlorine and the contact time.
Of the organisms that cause the following illnesses, which is the hardest to kill?
- Cholera
- Typhoid
- Cryptosporidiosis
- Infectious hepatitis
Cryptosporidiosis
At what range will fusible plugs on chlorine cylinders melt?
1. 147 - 152 F (64 - 67 C)
2. 155 - 159 F (68 - 71 C)
3. 157 - 162 F (69 - 72 C)
4. 167 - 171 F (75 - 77 C)
- 157 to 162 degrees
When a chlorine cylinder or container is changed, a new gasket should be used
1. every time.
2. after 2 uses.
3. after 3 uses.
4. after 4 or 5 uses.
- every time.
A(n) _____ is one or more short lengths of pipe, usually perforated, that quickly and uniformly disperses the chlorine solution into the main flow of water.
1. cylinder
2. injector
3. chlorinator
4. diffuser
- diffuser
What is the term for the treatment process used to destroy or inactivate disease-causing (pathogenic) organisms, such as viruses, bacteria, fungi, or protozoa?
Disinfection
What element is a dark reddish-brown liquid that vaporizes at room temperature and has a penetrating, suffocating odor?
Bromine
In the chlorination process, what term refers to the point beyond which the addition of more chlorine produces free residual chlorine?
Breakpoint
Which condition, caused by tiny particles of dirt and other impurities suspended in the water, can prevent good contact and protect pathogens during the disinfection process?
Turbidy
Virgin greensand can be regenerated by soaking the filter bed for several hours in a solution of chlorine containing
1. 50 mg/L Cl2
2. 75 mg/L Cl2
3. 100 mg/L Cl2
4. 200 mg/L Cl2
- 100 mg/L Cl2
Which process works best for sequestering manganese?
1. Sodium silicate alone
2. Sodium silicates and chlorine
3. Polyphosphates alone
4. Pholyphosphates and chlorine
- Polyphosphates and chlorine
When should polyphosphates used for sequestration of iron and manganese from a well be injected into the process?
1. Right after disinfection
2. Immediately after aeration to remove unwanted gasses
3. Right after clarification
4. Right after the water leaves the well
- Right after the water leaves the well
Which oxidant should be fed as early as possible in the treatment process to allow for complete reaction before it enters the distribution system?
1. Ozone
2. Chlorine dioxide
3. Chloramines
4. Potassium permanganate
- Potassium permanganate
Which adverse effects do the secondary contaminant, manganese have?
1. Unappealing to drink, undesirable taste, and possible indication of corrosion
2. Discolored laundry and changed taste of water, coffee, tea, and other beverages
3. Undesirable metal taste and possible indication of corrosion
4. Added total dissolved solids and scale, indication of sewage contamination and tastes
- Discolored laundry and changed taste of water, coffee, tea, and other beverages
When they are oxidized, iron and manganese change and discolor water from _____, depending on their concentration and presence or absence of other contaminants.
1. turbid yellow to black
2. clear to yellow
3. clear to white
4. dark yellow to white
- turbid yellow to black
The presence of iron and manganese in the distribution system often
1. reduces the need for chlorine.
2. provides a food source for bacterial growth.
3. rids the system of bacteria.
4. improves taste-and-odor problems.
- provides a food source for bacterial growth.
What type of filter uses a special type of medium that removes iron and manganese by a combination of both adsorption and oxidation?
Manganese greensand filters
Process recovery is a function of filter flow rate, length of the filtration cycle and what other factor?
Volume of water used in a backwash
A process in which polyphosphates or sodium silicates are added before the water is exposed to air or disinfectants is known as what?
Sequestration
Teeth are likely to become pitted when the fluoride concentration in drinking water goes above which amount?
1. 3 mg/L
2. 4 mg/L
3. 5 mg/L
4. 6 mg/L
- 4 mg/L
Sodium fluoride
1. was once called silly acid.
2. is a straw yellow color.
3. has a solution pH of about 1.0 pH units.
4. is odorless.
- is odorless.
How often should the fluoride concentration of treated water be measured?
1. Every 8 hours
2. Every 12 hours
3. Every day
4. Continuously
- Every day
Which type of fluoride chemical should be used in downflow saturators?
1. Tablets of sodium fluorosilicate
2. Granular sodium fluorosilicate
3. Crystaline sodium fluoride
4. Powdered sodium fluoride
- Crystaline sodium fluoride
Which is the commercial purity of Fluorosilicic Acid?
1. 20 - 30%
2. 20 - 40%
3. 30 - 40%
4. 35 - 48%
- 20 - 30%
A small amount of fluoride in the diet is essential for
1. proper tooth and bone formation.
2. healthy skin.
3. sharp vision.
4. a healthy heart.
- proper tooth and bone formation.
Fluoride is fed into the water system by either a solution feed system or a(n)
1. acid feed system.
2. dry feed system.
3. manual feed system.
4. continuous feed system.
- dry feed system.
What is the most inexpensive chemical available for fluoridation?
Sodium fluorosilicate
Compared to gravimetric feeders, what are TWO advantages of volumetric feeders?
Volumetric feeders are simple to operate and less expensive to purchase
The number of monthly distribution system chlorine residual samples required is
1. based on water withdrawal permit limit.
2. based upon system size.
3. based on the population served.
4. different for each state.
- based on the population served.
Under NO circumstances should a composite sample be collected for which type of analyses?
1. Bacteriological
2. Total dissolved solids
3. Alkalinity
4. Turbidity
- Bacteriological
Which of the following are the ideal indicator for pathogens?
1. Salmonella species
2. Coliform group bacteria
3. Gram-negative cocci
4. Gram-negative coccobacilli
- Coliform group bacteria
A _____ is a single-volume sample collected at one time from one place.
1. composite sample
2. continuous sample
3. random sample
4. grab sample
- grab sample
Consistency among laboratories in analytical results overseen by _____ and by state primacy programs for each of the types of analyses for which the laboratories are certified.
1. OSHA
2. AWWA
3. USEPA
4. NIOSH
- USEPA
If a sample arrives at a laboratory past the specified holding time following collection, the laboratory
1. must reject the samples.
2. can proceed with the samples only if the chain of custody is intact.
3. must reconstitute the samples.
must visually inspect the samples to determine their viability.
- must reject the sample(s).
How frequently do water treatment plant operators take samples?
Every day
What are three broadly classified areas from which samples are generally collected?
- Raw-water supply
- Treatment plant
- Distribution system
The treatment process that controls corrosion or scaling is known as
1. chemical control.
2. stabilization.
3. passivation.
4. corrosion kinetics.
- stabilization.
Which of the following is the principal scale-forming substances in water?
1. Zinc orthophosphate
2. Sodium carbonate
3. Calcium
4. Calcium carbonate
- Calcium carbonate
The buildup of corrosion products is a process known as
1. deposition.
2. elemental deposition.
3. physiological deposition.
4. tuberculation.
- tuberculation.
Iron deposits caused by the corrosion of cast-iron mains are called
1. rust specks.
2. floc.
3. tubercles.
4. scale.
- tubercles.
Which of the following is NOT a reason that corrosion and scaling are controlled?
1. To improve water quality
2. To reduce the need for quality sampling
3. To meet federal and state regulations
4. To protect public health
- To reduce the need for quality sampling
_____ can be broadly defined as the wearing away or deterioration of a material because of chemical reactions with its environment.
1. Corrosion
2. Rust
3. Oxidation
4. Scaling
- Corrosion
What are the basic methods for controlling corrosion or scaling?
- Adjustment of pH & alkalinity
- Calcium carbonate coating
- Corrosion inhibitors & sequestering agents
What are the primary reasons to control corrosion and scaling?
- Protect public health
- Improve water quality
- Extend the life of pipelines & plumbing
- Meet federal and state regulations
Certain types of bacteria can accelerate the corrosion process because they produce carbon dioxide and what other product?
Hydrogen sulfide
Which are the two principal chemicals that cause water hardness?
1. Aluminum and iron
2. Aluminum and calcium
3. Iron and manganese
4. Calcium and magnesium
- Calcium and magnesium
In general, soft waters that have a pH of less than 7 and that are slightly buffered will have what effect of lead and copper?
They will be corrosive
Recarbonation is
1. adding carbon dioxide to the water.
2. adding bicarbonate to the water.
3. adding acid to precipitate the excess lime in the water.
4. adding caustic soda to the water.
- adding carbon dioxide to the water.
Any material that forms a precipitate with the sodium salt of fatty acids (i.e., soap) can be referred to as
1. rust.
2. sulfate.
3. hardness.
4. residue.
- hardness.
The total hardness is the sum of calcium, magnesium, and
1. iron.
2. the primary anions.
3. all multivalent cations.
4. nitrate.
- all multivalent cations.
Which of the following can be used in place of lime soda ash for softening and will remove both carbonate and noncarbonate hardness?
1. Magnesium hydroxide
2. Iron sulfate
3. Magnesium sulfate
4. Sodium hydroxide (caustic soda)
- Sodium hydroxide (caustic soda)
When raw water contains little to no hardness, it can normally be softened through the use of
1. lime alone.
2. equal parts of lime and soda ash.
3. soda ash alone.
4. caustic soda.
- lime alone.
What comprises carbonate hardness?
Carbonate hardness is mostly attributed to:
- calcium carbonate
- magnesium carbonate
- calcium bicarbonate
- magnesium bicarbonate
What comprises noncarbonate hardness?
Noncarbonate hardness is attributed to calcium and magnesium compounds of chloride & sulfate; and sometimes nitrate
How is hardness expressed?
mg/L as calcium carbonate (CaCO3)
grains per gallon (gpg)
What are the principal cations that cause water hardness?
Calcium (Ca+2)
Magnesium (Mg+2)
Why is caustic-soda softening not a popular process even though it is effective?
Caustic-soda softening is more expensive than lime or lime and soda ash treatment, and it increases the total dissolved solids (TDS) in the treated water
Which process is used to concentrate sludge?
1. Sand bed
2. Solar lagoon
3. Thickener
4. Centrifuge
- Thickener
Powdered activated carbon (PAC) is usually added to the treatment process
1. before the normal coagulation-flocculation step.
2. before the sedimentation basin.
3. after the sedimentation basin.
4. in the filters.
- before the normal coagulation-flocculation process.
In the ion exchange softening process, once the resign can no longer soften water, it must be
1. renewed.
2. re-catalyzed.
3. regenerated.
4. recharged.
- regenerated.
The best place to control organics in drinking water is
1. in the treatment plant.
2. at the point of use.
3. at the source.
4. in the aqueduct.
- at the source.
Methane is only slightly soluble in water, so it is easily removed by
1. air stripping.
2. desorption.
3. adsorption.
4. aeration.
- aeration.
Ozone is _____, and maintaining a residual is difficult.
1. very unstable in water
2. extremely dense
3. unlikely to react with other elements found in water
4. nontoxic
- very unstable in water
What regulated substances can be removed by aeration?
- Radon
- Volatile Organic Chemicals
Which membrane process is most commonly called the “softening” membrane?
Nanofiltration
(Reverse Osmosis can also soften water)
Why is ultraviolet disinfection most suitable for groundwater?
Because it does not provide a lasting residual and is relatively low turbidity
What is the term for the gas transfer process used in water treatment to dissolve air into water?
Aeration
What is the process in which ions are transferred through a membrane as a result of a direct result of a direct electric current applied to the solution?
Electrodialysis
Which basic electrical unit is used to measure a material’s opposition to the flow of electricity?
1. Ampere
2. Ohm
3. Volts
4. Resistance or impedance
- Ohm
Which device consists of a pair of metallic plates that are separated by an insulating material called a dielectric?
1. Storage battery
2. Voltage regulator
3. Rectifier
4. Capacitor
- Capacitor
Which of the following is NOT a reason that meters, recorders, alarms, and automatic control systems are installed in a water plant?
1. To provide information for the operation of equipment
2. To reduce the need for written documentation
3. To improve the efficiency of operation
4. To improve the safety of working conditions
- To reduce the need for written documentation
The flow rate of liquid expressed in _____ is analogous to the flow rate of electricity in amperes.
1. gallons per day
2. liters per minute
3. megaliters per day
4. gallons per minute
- gallons per minute
What are some of the concerns about automatic control of treatment plants?
- Automated process sequences like filter backwashing may reduce opportunities for operators to observe & detect system malfunctions
- Operators must, therefore, introduce periodic observation into their daily routine
What does SCADA stand for?
Supervisory Control And Data Aquisition
- Computer control systems gather and display operational data for operator review
- Process changes can be automatic, semiautomatic, or manual
- Data can be displayed in digital form or using trend graphs
What’s an example of a feed-forward control?
When chemical feed is controlled proportional to the plant flow.
Friction reduces the flow of water through a pipe like _____ reduces the flow of electricity through a wire.
resistance
Electricity is often classified as either static or what?
Dynamic
Static electricity is often referred to as _____.
electricity at rest.
What type of electrical current flows continuously in one direction?
Direct current
The main purpose of mechanical seals is to
1. keep lubrication in and dirt and other foreign materials out.
2. control water leakage from the stuffing box.
3. keep contamination from entering or leaving.
4. save in costs, as they last longer than packing.
- control water leakage from the stuffing box.
The purpose of a packing is to
1. keep oil or graphite on the shaft.
2. control water leakage along the pump’s shaft.
3. prevent water leakage from a pump shaft.
4. help prevent the shaft from warping.
- control water leakage along the pump’s shaft.
Which part of a pump houses the packing or mechanical seal?
1. The shroud
2. The stuffing box
3. The volute
4. The casing head
- The stuffing box
Which of the following is the only type of pump that can be operated against a closed valve?
1. Vertical turbine pump
2. Centrifugal pump
3. Axial-flow pump
4. Mixed-flow pump
- Centrifugal pump
To prevent leakage at the point where the shaft protrudes through the case, _____ are used to seal the space between the shaft and the case.
1. lantern rings
2. packing rings
3. shaft sleeves
4. mechanical seals
- packing rings
Which type of pump is useful for moving water that contains solids, as in raw-water intakes?
Mixed flow pump
Which type of pump has an impeller rotating in a channel of constant cross-sectional area, which imparts mixed water or radial flow to the water?
Vertical turbine pump
Which type of pump is widely used for small, private wells because of its low initial cost and low maintenance, but is rarely used for public water systems because of its relatively low efficiency?
Jet pump
Which type of pump is designed such that the entire pump and motor unit can be placed below the water level in a well?
Submersible pump
Which of the following is the most important thing to consider in automatic startup after a power failure?
1. Operator safety
2. Power surges that could trip a breaker
3. Importance to treatment process
4. Importance to water quality
- Operator safety
Which part of the human body is most vulnerable to allowing microorganisms to enter it?
1. Stomach area, where most of the organs are located
2. Heart
3. Eyes
4. Throat and neck
- Eyes
Safety and safe working conditions are the responsibility of _____ associated with a water utility.
1. each individual
2. the supervisor
3. senior operators
4. safety committees
- each individual
Which of the following is NOT a class of employee designated to work in confined spaces?
1. Authorized attendant
2. Authorized entrant
3. Entry supervisor
4. Hazzard technician
- Hazzard technician
A(n) _____ for every chemical that is used in a water treatment plant should be kept in an organized fashion that is readily accessible to all employees.
1. log sheet
2. material safety data sheet
3. right-to-know sheet
4. hazard disclaimer
- material safety data sheet (MSDS) or safety data sheet (SDS)
After respiratory problems, effects of exposure to chlorine generally manifest as
1. rapid heart rate.
2. extreme weakness.
3. shaking of the hands.
4. irritation of the eyes.
- irritation of the eyes.
Where should an SDS (or MSDS) be kept?
In a location readily accessible to all employees
What is SCBA?
Self-Contained Breathing Apparatus
- it is used for chlorine leak repairs
What item of personal protective equipment is a type of respirator that supplies safe, grade D (or better) breathing air to the wearer?
SCBA - Self-Contained Breathing Apparatus
What is classified as a confined space?
A confined space has limited entry and exit, is not designed for continuous human occupancy, and is large enough for humans to perform work
How often should operators record bed expansion measurements, condition of and depth of media, and an evaluation of the bed surface?
1. Quarterly
2. Yearly
3. Daily
4. As determined by water condition
- Quarterly
It is important to keep process records of raw and finished water quality to determine
1. the condition of the equipment.
2. the need for continued sampling.
3. if processing is accomplishing its goals.
4. operator proficiency.
- if processing is accomplishing its goals.
Generally speaking, keep a _____ record of the amount of fluoride in the finished water and the raw water.
1. daily
2. biweekly
3. hourly
4. weekly
- daily
Main flushing records are best kept
1. in whatever location is most convenient for each operator.
2. in a secure location that can be accessed only by authorized personnel.
3. in a daily log folder.
4. in a searchable database.
- in a searchable database.
The general rule when talking to reporters is,
1. “give only yes or no answers.”
2. “don’t unless you absolutely have to.”
3. “leave them wanting more.”
4. “never give a straight answer.”
- “don’t unless you absolutely have to.”
Acute MCL violations must be reported to the public within what amount of time?
24 hours
Why are filter operation records important to keep?
- To detect trends in slow developing problems
- To make adjustments to optimize performance
Why are chemical usage records important?
- To anticipate needs to re-order chemicals to maintain a safe inventory
- To detect changes in usage over time
Which of the following is NOT typically a section covered in a sanitary survey?
1. Water sources
2. Storage facilities
3. Fire department hydrants
4. Water system management and operations
- Fire department hydrants
