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