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966 Cards in this Set
- Front
- Back
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The difference between the static level and pumping level on a well. |
Drawdown |
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This allows intake structures on lakes and reservoirs to pump water of the best quality. |
Ability to pump from multiple levels |
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Are the monthly changes in chemical and physical characteristics of groundwater and surface water sources typically consistent or variable? |
Groundwater: consistent year round Surface water: highly variable |
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Are coliform and other enteric microorganisms typically present in groundwater and surface water sources? |
Groundwater: normally absent Surface water: normally present |
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What are typical important dissolved gases of groundwater and surface water sources? |
Groundwater: CO2 and H2S Surface water: O2 |
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What are typical hardness and TDS characteristics of groundwater and surface water sources?
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Groundwater: generally high
Surface water: generally low |
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What are typical turbidity characteristics of groundwater and surface water sources?
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Groundwater: normally low
Surface water: highly variable |
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What are the three layers in a stratified lake or reservoir? |
Upper: Epilimnion Middle: Mesolimnion Lower: Hypolimnion |
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What are two conditions that can cause water in the bottom of a lake or reservoir to be circulated to upper levels. |
Fall turnover Prevailing directions winds causing “upwelling” |
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What is the minimum grouting necessary for the exterior of a well casing?
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The casing should be grouted from the surface down to the first impermeable layer
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What type of well has water in the well casing that moves above the upper confining layer in the aquifer?
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Artesian well
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The term used to describe subterranean strata able to yield or produce water. |
Aquifer |
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What type of aquifer has no confining layer? |
Water table aquifer
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Nuisance algae in lakes and reservoirs can be controlled with this chemical. |
Copper sulfate, CuSO4 |
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This chemical can enhance the effectiveness of copper sulfate when the total alkalinity of the water is greater than 150 mg/L.
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Citric acid |
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The land area draining into a reservoir or stream is called what?
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Watershed
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Industrial or agricultural activity directly above a shallow water table well can cause this.
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Contamination of the aquifer and well
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This is the upper saturated zone of an unconfined aquifer.
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Water table
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The development of significant daily changes in the pH and the total alkalinity of surface water indicates this.
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An increase in the algae population, with possible taste and odor problems.
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When the static water level in a well is normal and drawdown is less than normal, this is indicated. |
Worn or damaged pump impellers or turbines
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What is the proper way to abandon an existing well?
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Fill the well casing with cement grout or bentonite clay
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The two most common sources of taste and odor in surface water sources are what?
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Algae and decayed vegetation
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When algae occurs in sufficient numbers to alter the color of the water it is called what?
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Bloom |
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The two most common causes of taste and odor in well water. |
Dissolved gases such as hydrogen sulfide Minerals such as sulfates and iron |
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This condition at the bottom of stratified lakes may cause sediment minerals such as iron, manganese, and phosphate to be released into the water and may cause the production of hydrogen sulfide.
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Anaerobic conditions
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Activities (three) that should be limited or regulated on a watershed.
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Recreation such as hunting and camping Logging
Agriculture Mining |
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In stratified lakes or reservoirs, this is the region between the upper warm water layer and the colder water below.
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Thermocline OR mesalimnion |
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These three conditions can indicate that a groundwater source is under the influence of surface water.
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-Significant seasonal changes in water temperature
-Significant seasonal changes in water chemistry such as pH and alkalinity -Detection of insect body parts in the water |
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Typical range of pH for ground water and surface water.
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6.5 to 8.5
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What are the four main components of a water well?
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Sanitary seal
Casing Well screen Vent |
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This test procedure can provide a quick estimate of the total dissolved solids in the water.
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Specific conductance (conductivity)
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These conditions (3) may contribute to excessive nitrate levels in ground water.
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-Leaching from septic systems
-Agricultural fertilizers -Barnyard run-off |
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These conditions (6) may contribute to the corrosive characteristics of water. |
High dissolved oxygen Low pH Low alkalinity Soft water High water temperature Excess free CO2 |
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An estimate of the taste and odor characteristics of drinking water can be determined by this test. |
The threshold odor number test. |
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How do you determine the threshold odor number? |
The threshold odor is determined by diluting water samples with "odor free water" until there is no detectable odor. The amount of dilution determines the threshold odor number of the sample. |
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Microorganisms that can grow in the presence or absence of oxygen are called what? |
Facultative anaerobes |
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What are the following characteristics of P-alkalinity? - pH of endpoint - alkalinity measured |
- endpoint: pH 8.3 - alkalinity measured: all of hydroxide and 1/2 of carbonate |
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What are the following characteristics of ferrous iron: - solubility - appearance - valence charge |
- soluble in water - colorless - Fe 2+ also known as "clear water iron" |
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What are the following characteristics of ferric iron: - solubility - appearance - valence charge |
- low solubility - red-brown rust color - Fe 3+ also known as "red water iron" |
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High nitrate levels are more likely found in this type of water well. |
Shallow water wells |
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Colder water temperatures have this effect on the solubility of oxygen. |
The oxygen solubility increases |
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How do calcium and magnesium deposits left by minerals in water appear? |
Chalky white |
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How do iron deposits left by minerals in water appear? |
Reddish brown - rust color |
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How do manganese deposits left by minerals in water appear? |
Dark purple to black |
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These three ions contribute to the total alkalinity of water. |
Bicarbonate Carbonate Hydroxide |
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These four microorganisms are often associated with taste and odor problems in drinking water. |
Diatoms Green algae Blue-green algae Bacteria |
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Characteristics of M-alkalinity (methyl orange): - endpoint - alkalinity measured |
endpoint: 4.5
alkalinity measured: all of bicarbonate and 1/2 of carbonate |
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These ions are associated with water hardness. |
Calcium and magnesium |
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These (five) methods can be used to determine the corrosive or aggressive characteristics of water. |
Langlier Stability Index (LSI) Rysner Stability Index (RSI) Baylis curve Marble test (calcium carbonate stability test) Coupon test |
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Term used for corrosion caused by contact of two dissimilar metals. |
Galvanic corrosion |
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Excess carbon dioxide in well water can produce these effects. |
lower the pH cause the water to be corrosive |
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What is pH? |
negative log of the hydrogen ion concentration |
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Turbidity in water is due to the presence of these materials. |
suspended and colloidal particles of clay, silt, bacteria, etc. |
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This produces a "rotten egg" odor in drinking water. |
hydrogen sulfide gas |
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Indications of the Langlier Stability Index: Negative LSI Positive LSI LSI = 0 |
Negative: corrosive Positive: scale forming LSI = 0: stable |
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These tests must be made on grab samples and tested immediately. |
pH temperature dissolved oxygen chlorine residual |
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What is the range of the pH scale. |
0-14 |
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Indications of pH values: pH > 7 pH < 7 pH = 7 |
pH > 7 basic or alkaline pH < 7 acidic pH = 7 neutral |
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What is a primary cause of scale deposits in pipelines? |
deposition of insoluble carbonate compounds |
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Acidity and alkalinity are most often expressed in equivalents of this chemical. |
Calcium carbonate |
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The taste and odor problems associated with algae are exaggerated when exposed to this chemical. |
Chlorine |
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These materials may cause the formation of chlorinated organics such as trihalomethanes (THMs), when exposed to free chlorine. |
organic compounds, especially humic acids |
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These reagents are used in the total alkalinity test. |
0.02 N H2SO4 Bromcresol green - methyl red Methyl orange |
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These reagents are used in the total hardness test. |
EDTA pH 10 buffer colorizing agent |
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Difference in the pH and/or mineral content of drinking water in different communities can cause this problem. |
"Traveler's Diarrhea" |
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The Baylis Curve is a plot of these water quality parameters. |
pH and alkalinity |
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Chemical Symbols calcium iron sodium potassium magnesium manganese copper lead |
Calcium - Ca iron - Fe sodium - Na potassium - K magnesium - Mg manganese - Mn copper - Cu |
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The carrying capacity of iron pipes may be reduced due to the formation of this corrosion by-product. |
Iron oxide tubercules |
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Hardness and alkalinity are expressed as this. |
mg/L as calcium carbonate (CaCO3) equivalent |
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The light scattering matter in water is referred to as this. |
turbidity |
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Water that is suitable (safe) for drinking is called what? |
potable water |
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The pH range for alkalinity forms in natural water. - Bicarbonate only - Bicarbonate and carbonate |
Bicarbonate alkalinity is present in water with pH range of 4.3-8.5 Bicarbonate and carbonate alkalinity are present in water with a pH range of 8.5 to 10. |
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A measure of water's ability to neutralize acid, due to the presence of bicarbonate, carbonate, and hydroxide. |
total alkalinity, expressed as mg/L of calcium carbonate equivalent |
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Secondary MCLs Iron Manganese |
Iron - 0.3 mg/L Manganese - 0.05 mg/L |
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Problems (4) associated with hard water. |
- Large amount of soap required - Soap ring on fixtures, soap scum on clothes - Deposits of scale in pipes, water heaters, etc. - Scale deposits on fixtures |
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Problems associated with hydrogen sulfide drinking water. |
rotten egg odor |
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Problems (3) associated with iron in drinking water. |
fixture staining red water rusty off-taste to water |
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This equipment is used to measure turbidity in drinking water. |
nephelometric turbidimeter |
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Information necessary to determine the Langlier Stability Index. |
pH and pH of saturation |
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These are two causes of "red water." |
corrosion of iron based pipes growth of iron bacteria |
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This increases the amount of soap required to produce suds. |
Hardness |
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Anions associated with "carbonate hardness" and "non-carbonate hardness." |
Carbonate hardness: bicarbonate and carbonate Non carbonate hardness: sulfate and chloride |
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This element must be present in order for corrosion to occur. |
oxygen |
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Water has greatest density at this temperature. |
4oC or 39.2oF |
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Maximum filtration rate for rapid sand filters. |
2.0 gallons per minute per square foot for turbidity removal 3.0gallons per minute per square foot for iron removal. |
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Characteristics of the coagulation process Type of reaction Time required Mixing intensity |
Type of reaction: physical - chemical Time required: reaction complete in seconds Mixing intensity: high intensity is required for proper coagulation |
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Advantages of dual and mixed media filters over plain rapid sand filters. |
higher filtration rate longer filter runs |
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When refilling a rapid sand filter that has been out of service, this procedure will avoid displacement of the filter media. |
slowly fill the filter through the backwash valve |
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Characteristics of polymers: Cationic polymer Anionic polymer Non-ionic polymer |
Cationic polymer - positive charge Anionic polymer - negative charge Non-ionic polymer - no net charge |
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Characteristics of the flocculation process: type of reaction time required mixing intensity |
type of reaction - physical
time required - 30-45 minutes mixing intensity - controlled slow mixing |
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Three general coagulants typically used in the water treatment industry. |
Alum/aluminum sulfate Iron salts Low molecular weight cationic polymer |
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Optimum pH for coagulation: Alum Ferric sulfate Cationic polymer |
Alum - 5-7 Iron salts - 4-11 Cationic polymer - wide range of pH |
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Minimum rapid sand backwash rate. |
18.75 gpm/sq ft |
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The overall charge on a colloidal particle is determined by measuring this. |
Zeta potential |
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This may develop as a result of inadequate backwash of a rapid sand filter. |
Mudball formation |
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Performance of a sedimentation basin can be improved with the addition of these. |
tube or plate settlers |
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The formation of bubbles near the bottom of a rapid sand filter can be referred to as this. |
air binding |
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These can be used to enhance the coagulation-flocculation process. |
activated silica (coagulant aid) or bentonite clay (weighting agent) |
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Result of wrong flocculator paddle speed. |
paddle speed too low: poor floc formation; turbidity settles out in floc basin paddle speed too high: floc particles break up |
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Repeated appearance of localized sand boil during backwash indicates this. |
disturbance of filter bed support gravel, or displacement of underdrain |
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This is required for alum to coagulate turbidity. |
alkalinity |
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Characteristics of a multi-media filter. |
Top layer: Anthracite coal 1.4 mm diameter 1.4 specific gravity Middle layer: medium silica sand 0.8 mm diameter 2.6 specific gravity Lower layer: fine garnet sand 0.5 mm diameter 4.1 specific gravity |
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Cold water temperature has this effect on floc settling. |
the floc settling rate is slower, due to the slight increase in the density of water |
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These physical processes describe the removal of turbidity in a sand filter. |
straining adsorption sedimentation |
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This is the cause of air binding in filters. |
negative head (partial vacuum) near the bottom of the filter |
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Improper dosing of filter aid polymer can cause these problems. |
overdose: shortened filter run due to rapid increase in headloss
underdose: shortened filter run due to turbidity breakthrough |
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This is required during filter backwash, to provide equal media expansion at different water temperatures. |
the backwash rate can be increased slightly as the water temperature increases |
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These are used to optimize coagulant dosage. |
pilot filter streaming current monitor jar test zeta potential |
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This instrument measures the zeta potential of coagulated turbidity particles. |
streaming current monitor |
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Sedimentation basins are provided with inlet baffles to prevent this. |
short circuiting |
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This is a typical slow sand filtration rate. |
0.05-0.1 gpm/sq ft |
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This must develop on the surface of a slow sand filter in order for proper filtration. |
schmutzdeke |
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These should be monitored continuously during operation of filters. |
flow rate headloss filter effluent turbidity |
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Properly operating filter surface sweeps will accomplish this. |
break-up of mudballs and surface mats |
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Functions of a filter underdrain. |
collect and remove filtered water distribute backwash water to filter media |
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This is the most important form of natural alkalinity in surface. |
Bicarbonate
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These chemicals can be added to water as artificial alkalinity. |
Hydrated lime - Ca(OH)2 - slaked lime Soda ash - Na2CO3 - sodium carbonate Caustic soda - NaOH - sodium hydroxide |
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The function of filter aid polymer. |
cause turbidity floc particles to bind to filter media |
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Filter backwash is indicated when this occurs. |
filter head loss reaches critical level (6-10 ft) filter effluent turbidity increases filter volume production |
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Indications of inadequate filter backwash. |
filter mats filter bed cracks mud balls |
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This is required when the headloss in a slow sand filter becomes excessive. |
the filter is taken out of service and the upper most layer of sand and dirt are removed |
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If settled sludge is left in the sedimentation basin too long, this may occur. |
finished water taste and odor problems may develop |
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These valves are open during normal rapid sand filter operation. |
filter influent valve filter effluent valve |
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These valves are open during a backwash cycle of a rapid sand filter. |
backwash to waste valve surface wash valve backwash valve |
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The effluent from a freshly backwashed filter should be directed here.
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to waste; the first water through the filter is often of inferior quality, and should not be directed to the finished water clear well.
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The “rule of thumb” ratio of alum to alkalinity for proper coagulation. Alum: natural alkalinity Alum: hydrated lime
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Alum: natural alkalinity = 2:1 2 parts alum: 1 part alkalinity; Alum: hydrated lime = 4:1 4 parts alum: 1 part hydrated lime
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The effluent from a freshly backwashed filter should be directed here.
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to waste; the first water through the filter is often of inferior quality, and should not be directed to the finished water clear well.
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The “rule of thumb” ratio of alum to alkalinity for proper coagulation. Alum: natural alkalinity Alum: hydrated lime
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Alum: natural alkalinity = 2:1 2 parts alum: 1 part alkalinity; Alum: hydrated lime = 4:1 4 parts alum: 1 part hydrated lime
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Overdose of alum coagulant can result in this.
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excess aluminum ion in the finished water and/or precipitation of alum floc in the distribution system.
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Important control parameters for a solids contact clarifier, it is important to do this.
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maintain optimum solids level in the blanket.
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Mud balls can create these problems in a rapid sand filter.
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“channeling” of water through the filter media and premature turbidity breakthrough
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This may occur if a rapid sand filter is operated at too high head loss.
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the filter may experience turbidity breakthrough or air binding
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The major advantage of using an iron salt such as ferric chloride instead of alum as a coagulant.
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iron salts are more effective over a broader range of pH
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Air binding in a filter can cause this problem.
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non-uniform filtration throughout the bed
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Headloss that indicates need for backwash.
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6-10 ft of headloss
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These positively charged ions are primarily responsible for water hardness.
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calcium and magnesium
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Permanent hardness is associated with these anions.
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chloride and sulfate
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Used to recharge zeolite ion exchange softeners.
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sodium chloride salt brine
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This provides recarbonation during the lime-soda softening process.
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carbon dioxide CO2
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This can be used to remove soluble organics, including taste and odor from water. |
activated carbon (PAC and GAC) |
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Chlorine that reacts with phenolic compounds in water can produce this problem.
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taste and odor
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Chemicals effective in the treatment of taste and odor compounds.
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potassium permanganate – oxidation of T & O; chlorine dioxide – oxidation of T & O; ozone – oxidation of T & O; free chlorine – oxidation of T & O; activated carbon – adsorption of T & O
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Changes in these can reduce the corrosive characteristics of water: Alkalinity Hardness pH
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alkalinity – increase; hardness – increase; pH – raised
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Special sand used for iron removal.
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manganese greensand
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Used to control iron “red water” problems.
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metaphosphates
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Removal of noncarbonate calcium hardness by chemical precipitation requires the addition of this.
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carbonate, usually in the form of soda ash Na2Co
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This method of softening also reduces the total dissolved solids (TDS) of the water.
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chemical precipitation by the lime-soda process
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Insufficient recarbonation during the lime-soda process can cause this filter problem.
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incrustation of calcium carbonate on the filter media causing growth in the size of the filter grains.
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This ion is added to water during zeolite ion exchange softening.
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Sodium, Na
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Manganese greensand iron removal filters are re-generated with this.
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potassium permanganate, KMnO4
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Metaphosphate added to control iron “red water” should be added to the water before this.
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before the addition of chlorine
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This can be used to keep iron and manganese in solution.
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metaphosphate
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Amount of salt required to regenerate a zeolite softener.
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0.2 – 0.5 lb salt / 1000 grain capacity
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Pink water in the effluent of a permanganate / green sand iron treatment system indicates this.
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the permanganate dose is too high.
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Recarbonation of lime-soda soften water is done for this reason.
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to reduce the scale and incrusting characteristics of the water
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Iron in this form causes “red water” problems.
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ferric iron
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Nitrate can be removed from potable water with these methods.
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ion exchange; reverse osmosis
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THMs can be removed from water with this treatment.
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activated carbon adsorption
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This occurs during the regeneration of zeolite ion exchange resin.
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hardness ions are displaced and sodium ions are replenished on the surface of the resin
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Problems that may occur in the operation of an ion exchange softener.
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insoluble iron and manganese deposits on the resin beds
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This softening process does not significantly change the total dissolved solids (TDS) content of the water.
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ion exchange process; calcium and magnesium ions are simply replaced with sodium ions, which leave the TDS of the water about the same
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Purpose of recarbonation.
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stop continued precipitation of calcium carbonate after softening
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Replacement of granular activated carbon is required at this point.
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when removal of soluble organic material is inadequate. The adsorption sites on the carbon eventually become filled.
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Activated carbon has this effect on chlorine residual.
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the chlorine residual will be reduced to zero
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This causes water to move across a semipermeable membrane during reverse osmosis treatment.
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water pressure
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Bacteria and other microorganisms can cause these problems for reverse osmosis treatment and equipment.
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membrane fouling; membrane breakdown or deterioration; module plugging
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These may be used to raise the pH and/or alkalinity of water.
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quick lime – CaO; hydrated lime - Ca(OH)2; caustic soda – NaOH; soda ash – Na2CO3
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Free or “aggressive”CO2 can cause this problem.
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corrosion in the distribution system
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These can be used to coat distribution system piping to reduce corrosion.
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silicate compounds; phosphate compounds; calcium carbonate
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Optimum pH for the removal of iron and manganese by aeration.
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8 – 9
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Removes these forms of hardness: carbonate hardness; non-carbonate hardness
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removes carbonate hardness: hydrated lime Ca(OH)2; removes non-carbonate hardness: soda ash Na2CO3
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When phosphates are used for iron control, and chlorine is used for disinfection, this is the order to add them to water.
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add the phosphate before the chlorine
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Chlorine formulations used in the water industry.
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molecular chlorine (gas) Cl2; sodium hypochlorite (liquid solution) NaOCl; calcium hypochlorite (solid) Ca(OCL)2
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This is what appears after the “breakpoint” is reached in chlorine disinfection.
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residual chlorine
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Major factors that determine the effectiveness of chlorine. |
concentration of residual chlorine – higher residual = better disinfection; time chlorine is in contact with water – higher contact time = better disinfection; temperature of water - higher temperature = better disinfection; pH of water – low pH = better disinfection; residual type – free residual = better disinfection |
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Cl2 + H2O =
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HOCl + HCl hypochlorous acid + hydrochloric acid |
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These can cause chlorine demand.
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reducing agents:
iron, ferrous+2 manganese, Mn+2 hydrogen sulfide, H2S organic material |
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HOCL (free chlorine) + NH3 (ammonia) react to form
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NH2Cl + H2O (monochloramine + water)
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Customer complaints about chlorine taste and odor in water are due to small concentrations of this form of chlorine.
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nitrogen trichloride (tri-chloramine) NCl3
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The pH of water has this effect on free residual chlorine.
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pH below 7.5 – hypochlorous acid present, improved disinfection; pH above 7.5 – hypochlorite ion present, decreased efficiency
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Approved disinfectants for Tennessee public water systems. |
chlorine; ozone; chlorine dioxide |
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Three methods used to measure chlorine residual.
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colorimetric (DPD)
amperometric titration starch-iodine titration |
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Definition of coliform bacteria group.
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gram negative, rod shaped, non-spore forming, facultative anaerobic and aerobic bacteria able to ferment lactose to gas within 48 hours at 35oC
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Types of coliform bacteria.
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fecal coliform bacteria that live in the intestine of warm blooded animals; non-fecal coliform bacteria that live in soil and decaying vegetation
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EPA approved methods for determining the presence of coliform bacteria in water.
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multiple tube fermentation; membrane filter method; presence absence broth; MMO-MUG, Colilert
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Most common fecal coliform bacteria.
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E. coli
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Media used in the multiple tube fermentation test.
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presumptive step: lauryl tryptose broth (LTB); confirmed step: brilliant green lactose bile broth (BGLBB)
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Meaning of “facultative anaerobe.”
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able to live in the presence or absence of molecular oxygen
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Avoid these when taking bacteriological sample.
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swivel faucet; water cooler; faucet with aerator (remove aerator); garden hose; hose bib that is too low to the ground or is close to vegetation
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Method for disinfecting distribution mains before they are placed into service.
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disinfect with chlorine at 50 mg/L for 24 hours; at least 25 mg/L must remain after 24 hour period
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Pathogenic
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disease causing
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Definition: Disinfection; Sterilization
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disinfection – destruction of harmful or undesirable microorganisms; sterilization – complete destruction of all life
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Enteric
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associated with the intestinal tract of animals
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Bacteriological samples that require more than 1 hour of transport to the laboratory require this.
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maintain at approximately 4oC on ice
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Free chlorine residual composition.
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hypochlorous acid (HOCl) + hypochlorite ion (OCl-)
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Sample volume needed for coliform bacteria test.
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100 mL +/-2 mL
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These react to form chlorine dioxide.
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chlorine (Cl2) and sodium chlorite (ClO2)
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This indicates a positive fermentation tube during the coliform test.
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gas in the fermentation tube
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Presence of coliform bacteria indicates this. Total coliform bacteria; Fecal coliform bacteria
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total - bacteria of intestinal or soil/vegetation origin, which may indicate the presence of disease causing microorganisms; fecal - bacteria that originate in the intestinal tract of humans or animal, indicating fecal contamination and may indicate the presence of disease causing microorganisms
|
|
|
Chlorine can have this effect on the taste and odor of water.
|
increase or exaggerate taste and odor due the formation of chlorinated organic compounds
|
|
|
This is destroyed during breakpoint chlorination.
|
combined residual, chloramines
|
|
|
Chlorine dose =
|
demand + residual
|
|
|
The number of bacteriological samples required each month is based on this.
|
population size
|
|
|
Chlorine left after the demand has been met.
|
chlorine residual
|
|
|
Waterborne infectious diseases
|
typhoid; cholera; dysentery; giardiasis; polio; gastroenteritis; cryptosporidiosis
|
|
|
“Rule of thumb” for disinfection power of chlorine residual forms.
|
hypochlorous acid is 100 times more effective than hypochlorite ion; hypochlorous acid is 1000 times more effective than mono chloramine
|
|
|
Advantages of chlorine dioxide over free chlorine.
|
does not react with organic material to form THMs; effective over a wide pH range, including pH above 7.5; effective oxidation of taste and odor compounds
|
|
|
Characteristics of ozone.
|
power disinfectant; does not form stable residual in water; disinfection properties not affected by the pH of water
|
|
|
Bacteria shapes.
|
bacillus “rod”; coccus “sphere”; spirillum “cork screw”
|
|
|
When using solid chlorine tablets to disinfect water mains, the tablet should be placed here.
|
at the top of the pipe
|
|
|
This material reacts with free chlorine to form THMs.
|
organic material, especially humic material from decaying vegetation
|
|
|
Chemicals produced with the reaction of chlorine and ammonia.
|
monochloramine – NH2Cl; di chloramine – NHCl2; nitrogen trichloride – NCl3
|
|
|
Disinfection CT.
|
disinfection concentration (mg/L) x contact time (minutes)
|
|
|
Inactivation requirements for Cryptosporidium; Giardia cysts; Viruses |
crypto - 3 log inactivation or 99.9%; giardia – 3 log inactivation of 99.9%; viruses – log inactivation or 99% |
|
|
Characteristics on enteric viruses in water.
|
smallest living organisms; cause certain waterborne infections such as hepatitis A and polio; may be more resistant to disinfection than coliform bacteria
|
|
|
Manner of reporting coliform bacteria in drinking water samples.
|
coliform present or coliform absent
|
|
|
Minimum repeat samples required in response to a positive coliform sample.
|
three, one at the original tap, one at a tap within 5 connections downstream, and one at a tap within 5 connections upstream
|
|
|
Turbidity can have these effects on disinfection.
|
react to produce chlorine demand; “hide” bacteria and other microorganisms from disinfectant action
|
|
|
Method used to disinfect tank or reservoir walls.
|
spray or brush a 100-200 mg/L chlorine solution on the surface of the tank and allow to react for 3 hours
|
|
|
Steps to insure a proper bacteriological sample.
|
allow the tap to run for 1-5 minutes in order to sample from the main; do not rinse the bottle; do not touch any part of the bottle that will come in contact with the sample; do not over-fill the sample bottle, fill to approximately 80% full; transport the sample immediately to the lab; store on ice if longer than 1 hour transport time; properly label the sample
|
|
|
Distribution system bacteriological sampling should be located here.
|
at representative locations throughout the distribution system
|
|
|
Color reaction of chlorine and DPD.
|
pink to red
|
|
|
Minimum free chlorine residual to be maintained throughout the distribution system.
|
0.2 mg/L
|
|
|
Characteristics of chlorine gas.
|
greenish yellow gas; non-flammable, but supports combustion; 2.5 times heavier than air
|
|
|
One volume of liquefied gas chlorine will produce this volume of gas.
|
approximately 460 volumes of gas
|
|
|
Destroys chlorine in a bacteriological sample bottle.
|
sodium thiosulfate Na2S2O3
|
|
|
MCL
|
maximum contaminant level
|
|
|
EPA approved methods of surface water filtration.
|
conventional rapid sand filtration; direct filtration; slow sand filtration; diatomaceous earth
|
|
|
This indicates an “acute” coliform violation.
|
fecal coliform or E. coli positive sample followed by a total coliform positive repeat sample OR; total coliform positive sample followed by a fecal coliform or E. coli positive repeat sample
|
|
|
Contaminants indicated by the following acronyms: SOC; VOC; IOC
|
synthetic organic compounds; volatile organic compounds; inorganic compound
|
|
|
Bacteriological samples that test positive for total coliform bacteria must also be tested for this.
|
E. coli
|
|
|
Examples of inorganic contaminants.
|
cadmium; asbestos; chromium; mercury; fluoride; nitrate/nitrite
|
|
|
Examples of volatile compounds.
|
benzene; ethyl benzene; toluene; xylene
|
|
|
Action level: Lead; Copper
|
lead: 0.015 mg/L or 15 ppb; copper: 1.3 mg/L
|
|
|
Health concern of lead in drinking water.
|
nervous system impairment that can affect the mental development, especially in children
|
|
|
Health concern of nitrate in drinking water.
|
met-hemeglobinemia or blue baby syndrome
|
|
|
Vents on covered water storage tanks should be protected in this manner.
|
pointed down and screened
|
|
|
MCL for common water contaminants: THM; Nitrate; Fluoride
|
THM: 0.08 mg/L; Nitrate: 10.0 mg/L; Fluoride: 4 mg/L
|
|
|
Backflow can occur due to these hydraulic conditions.
|
backpressure and backsiphonage
|
|
|
This provides the highest level of backflow protection.
|
air gap separation
|
|
|
Cross connection
|
any actual or potential physical connection between a potable water pipe and pipe, vessel or machine containing a non-potable fluid so that it is possible for the non-potable fluid to enter the potable system by backflow
|
|
|
Conditions that may produce backpressure backflow.
|
elevated piping, for example, a water service to a multi-story building; potable water connection to the discharge side of a pump, for example, a potable interconnection with an irrigation well pump; thermal expansion, for example, a potable water make-up line to a boiler
|
|
|
These can be used to protect potable water from high hazard cross connections.
|
air gap; reduced pressure backflow assembly (RPBA)
|
|
|
These protect against back siphonage only.
|
atmospheric vacuum breaker (AVB); pressure vacuum breaker (PVB)
|
|
|
Plumbing code prohibits this connection.
|
potable water connection to a sewer connected waste
|
|
|
This backflow assembly is for low hazard applications only.
|
double check valve assembly (DCVA)
|
|
|
The surface water treatment rule requires that all cryptosporidium, giardia, and viruses be inactivated to this level.
|
crypto: 2 log; giardia: 3 log; viruses: 4 log
|
|
|
In order to determine the disinfection contact time, it may be necessary to do this to a tank or reservoir.
|
perform a tracer study on the tank or reservoir
|
|
|
These methods can be used to measure the fluoride concentration in drinking water.
|
fluoride specific ion electrode; colorimetric (SPADNS)
|
|
|
These situations require the water supplier to make public notification.
|
an MCL has been exceeded; there has been a sampling or reporting violation; the water system is operating under a variance or waiver
|
|
|
This entity must approve a water system bacteriological sampling plan.
|
approval by the state (TDEC) or other agency having jurisdiction is required
|
|
|
The health concerns of excess fluoride in drinking water.
|
mottled (discolored) teeth; skeletal fluorosis (misshaping) of the bones
|
|
|
Coliform MCL
|
more than one positive sample per month (0-40 samples/month); more than 5% positive samples per month (more than 40 samples/month)
|
|
|
Radioactive gas regulated in drinking water.
|
radon
|
|
|
Units of expression used for radioactive contaminants.
|
pico curries / liter, pCi/L
|
|
|
Units of expression used for asbestos in drinking water.
|
million fibers / liter, MFL
|
|
|
Water service to a home or facility where there is an auxiliary water system requires this.
|
a backflow prevention assembly at the service connection to the home or facility
|
|
|
Most of the lead in drinking water comes from this source.
|
corrosion of plumbing materials
|
|
|
Plumbing materials that may contribute lead to drinking water.
|
lead based solder used on copper plumbing; brass or chrome plated brass faucets; galvanized (zinc plated) pipe and fittings; lead service pigtails
|
|
|
Sources of SOC’s in drinking water.
|
industrial solvents; agricultural pesticides
|
|
|
General health concern for VOC’s and SOC’s in drinking water.
|
cancer
|
|
|
Carcinogenic
|
cancer causing
|
|
|
Primacy
|
authority for state to implement and enforce a federal regulation such as the SDWA
|
|
|
Contaminants that are not regulated under the federal SDWA and have no specific health affect.
|
secondary contaminants (secondary MCLs)
|
|
|
Drinking water contaminants regulated because of a health concern.
|
primary drinking water standard
|
|
|
Normal startup amps for a pump motor.
|
3 to 5 times the running amps
|
|
|
Pumping term for the vertical distance from inlet water level to discharge water level.
|
total static head
|
|
|
Slow opening valves on high pressure pumps are important to avoid this problem.
|
water hammer when the pump starts
|
|
|
Define pump shutoff head.
|
the maximum head that can be developed by a centrifugal pump operating at a set speed
|
|
|
Operating a centrifugal pump at or near shut-off for an extended period can cause these problems.
|
pump damage due to overheated water or impeller vibration; very poor pump efficiency
|
|
|
Define pump runout.
|
the maximum flow that can be developed by a centrifugal pump without damaging the pump
|
|
|
Operating a centrifugal pump near runout on the pump curve can cause these problems.
|
motor damage due to excessive amp draw; very poor pump efficiency
|
|
|
Stages or bowls are added to a centrifugal pump to increase this.
|
increase the total head that the pump can produce
|
|
|
Cause of pump cavitation.
|
too high suction lift; plugged suction line; too high pump speed; warm water temperature; throttled suction valve; significant drop in pump discharge head
|
|
|
Air leaking into the suction piping of a centrifugal pump can cause these problems.
|
loss of prime; air lock of the pump
|
|
|
Most common liquid chemical dosing pumps.
|
positive displacement piston pump; positive displacement diaphragm pumps
|
|
|
Materials used to make pump packing.
|
jute, hemp, cotton, teflon, graphite
|
|
|
Lubrication materials used on equipment should conform to this.
|
manufacturer’s specifications
|
|
|
This can protect steel tanks and pipes from galvanic type corrosion.
|
cathodic protection
|
|
|
A gauge on the discharge side of an operating centrifugal pump measures this.
|
dynamic discharge head (static discharge head + discharge friction losses)
|
|
|
A gauge on the suction side of an operating centrifugal pump measures this.
|
dynamic suction head
|
|
|
Function of seal water supplied to the stuffing box of a centrifugal pump.
|
cools packing and shaft
lubricates shaft flushes grit and other debris away from the shaft |
|
|
Provides proper tension on pump packing.
|
packing gland, which is adjusted with gland nuts
|
|
|
Pumps that discharge into a common header pump.
|
connected in parallel
|
|
|
When one leg of three phase power to a motor is lost, the pump motor will do this.
|
single phasing
|
|
|
Amp readings when a three phase motor operates under single phase.
|
amperage in one leg is very high, and the amperage on the other two legs is zero
|
|
|
This can be done to change the rotation direction of a three phase pump motor.
|
switch any two of the three motor leads
|
|
|
The function of a pump lantern ring.
|
distribute seal water to the pump packing
|
|
|
“Rule of thumb” for leakage from pump packing.
|
one drip per second for each inch of shaft diameter
|
|
|
Rotating component in a centrifugal pump.
|
impeller
|
|
|
Check valve used to maintain centrifugal pump prime.
|
foot valve
|
|
|
This can be adjusted to change the output of a positive displacement feed pump.
|
pump stroke length
pump speed pump “on” time interval |
|
|
Loss of vacuum to a gas cylinder could be caused by these problems.
|
plugged injector head
reduced water flow rate to injector head |
|
|
“Rule of thumb” for maximum daily removal of chlorine from a cylinder. 150 lb cylinder; 1-ton cylinder
|
approximately ¼ of full tank net weight per 24 hours, or
- 40 lb/day for 150 lb cylinder - 400 lb/day for 1-ton cylinders |
|
|
Temperature that melts the chlorine cylinder fusible plug.
|
approximately 158oF
|
|
|
Failure of a hypochlorinator could result from this condition.
|
build-up of mineral deposits within the hypochlorinator
|
|
|
Short circuiting in tanks and clarifiers can be reduced with these.
|
baffles, placed in strategic locations
|
|
|
Term for build-up of oxide deposits in steel or iron pipes.
|
tuberculations
|
|
|
Corrosion that occurs due to the contact of dissimilar metals.
|
galvanic corrosion
|
|
|
Method to calibrate the output of a dry chemical feeder.
|
weigh the output of the feeder at various auger speeds, develop a calibration graph from the data collected
|
|
|
Method to calibrate the output of a liquid chemical feeder pump.
|
use a volumetric container on the suction inlet to the solution pump to determine the output at various settings, develop a calibration graph from the data collected
|
|
|
Tubercule formation in distribution system piping can do this to the Hazen and Williams roughness coefficient for the pipe.
|
the Hazen and Williams “C” factor will be lowered
|
|
|
Symptoms of a plugged gas chlorine injector head.
|
the chlorine flow is zero
the chlorine cylinder pressure is normal the vacuum is low |
|
|
This material is often used as the “sacrificial anode” in cathodic protection of steel tanks and pipes.
|
magnesium
|
|
|
Problems associated with pump cavitation.
|
pitting damage to impeller and pump volute case
poor pump efficiency |
|
|
Closing or opening a valve too quickly can cause this problem.
|
water hammer
|
|
|
The principle operation of a reduced pressure backflow assembly.
|
water will not flow from a zone of low pressure to a higher pressure
|
|
|
Amperage draw on a pump motor as the pump discharge valve is closed.
|
the amperage draw will go down
|
|
|
Unit installed in pump stuffing box in a water treatment plant.
|
mechanical seal
|
|
|
This can interfere with accurate dispensing of a dry chemical.
|
moisture build-up in the dry chemical, which interferes with the free flow of the chemical
|
|
|
These conditions may result in loss of filter media. (3)
|
too high backwash rate
air binding in the filter improper location of backwash troughs |
|
|
Gate valves are designed to be operated in these positions. |
fully open or fully closed |
|
|
Over-lubrication of pump or motor bearings can result in this.
|
bearing failure |
|
|
Misalignment of the motor and pump shafts can result in this. |
vibration and premature failure of pump and/or motor bearings |
|
|
These conditions can cause a centrifugal pump to discharge at a reduced rate. |
plugged or worn impeller
wrong pump speed partial plug on suction or discharge side of pump |
|
|
Used to prevent severe drop in pressure on the suction side of a booster pump. |
low pressure cut-out switch |
|
|
This should be replaced each time a chlorine cylinder is changed. |
Lead gasket Lead gasket Lead gasket |
|
|
Change in flow that occurs when a second identical pump is turned on and pumps into a common header. |
the flow will increase, but never equal twice the capacity of the single pump |
|
|
Intersection of the head-capacity curve and the system curve. |
pump operating permit |
|
|
The point on a pump performance head-capacity curve where efficiency is highest. |
best efficiency point (BEP) |
|
|
The schedule rating on plastic pipe indicates this. |
pipe wall thickness |
|
|
Initial signs of failure of a gear drive mechanism. |
noise vibration excess heat |
|
|
This may be happening if the pump sounds like it is pumping "rocks," or makes a pinging sound. |
the pump may be cavitating |
|
|
Surrounds the pump impeller. |
volute case |
|
|
Used to remove the calcium deposits on hypochlorinator equipment. |
dilute acid solution |
|
|
Apparatus used to measure the flow rate from a fire hydrant. |
pitot meter |
|
|
Basic unit of electrical power. |
watt |
|
|
Electricity: Current flow Electrical potential |
current flow: amps (I) electrical potential: volts (E) |
|
|
Location of chlorine cylinder fusible plug. |
150 lb cylinder: in the cylinder valve 1-ton cylinder: three plugs located on each end of the cylinder |
|
|
Suction lift for a centrifugal pump, at sea level: Practical lift Theoretical lift |
practical: 15-20 ft theoretical: 33.9 ft |
|
|
Function of wearing rings in a centrifugal pump. |
prevents pump internal recirculation |
|
|
The "C" factor for a pipe indicates this. |
the internal roughness of the pipe |
|
|
Excessive withdrawal of gas chlorine from a cylinder may result in this. |
formation of chlorine "ice" in the line between the cylinder and the chlorinator |
|
|
Hazards associated with the handling or storage of powered activated carbon (PAC). |
fire or explosion hazard suffocation hazard due to displacement of oxygen |
|
|
A self contained breathing apparatus (SCBA) should be located here. |
on a wall just outside of the chlorine facility |
|
|
Exhaust vents for chlorine handling facilities should be located here. |
near the floor of the chlorine facility |
|
|
Exposure to chlorine can result in these life threatening conditions. |
suffocation secondary respiratory infection leading to pneumonia pulmonary edema (water on the lungs) |
|
|
Chlorine gas is visible at this concentration in the air. |
100 ppm |
|
|
Use this to detect small chlorine leaks. |
ammonia soaked rag or squeeze bottle containing cotton soaked with ammonia |
|
|
These are used to repair chlorine container leaks. |
A kit - 150 lb cylinder B kit - 1 ton cylinder C kit - railcars |
|
|
Water can do this to a chlorine cylinder leak. |
cause the leak to become worse |
|
|
Density of chlorine gas. |
2.5 times as dense as air |
|
|
This must be done if an accident occurs. |
the accident must be reported immediately |
|
|
Hazardous gases that may be encountered in a confined space. |
hydrogen sulfide - H2S carbon dioxide - CO2 methane - CH4 carbon monoxide - CO |
|
|
Hazards associated with hydrogen sulfide. |
explosion hazard respiratory and nervous system toxin |
|
|
Hazard associated with shock by low voltage. |
heart fibrilation |
|
|
Minimum amperage considered lethal. |
1/3 amp |
|
|
Hazard created by mixing chlorine and ammonia solutions. |
toxic gas is produced |
|
|
Safety precaution that should be used whenever working on electrical equipment. |
the electrical panel that energizes the equipment should be properly locked out and tagged |
|
|
Area or enclosure with limited ventilation and/or restricted or limited entrance and exit. |
confined space |
|
|
The way that acid and water should be added together. |
always add acid to water, while stirring |
|
|
Recommended initial response to serious chlorine leak. |
move to high ground, up-wind of the chlorine gas cloud |
|
|
Individual who is trained to recognize the hazards associated with trenches and excavations, and who is authorized to implement proper safety procedures. |
competent person |
|
|
Oxygen concentrations: normal atmosphere minimum safe level maximum safe level |
normal: 21% minimum: 19.5% maximum: 23.5% |
|
|
Common hazards associated with confined spaces. |
explosive atmospheres (methane, gasoline, vapors, etc.) toxic atmospheres (hydrogen sulfide, carbon monoxide, etc) low oxygen atmospheres |
|
|
Safety precautions to take when there is a requirement to work in a confined space. |
-provide continuous ventilation before entering, and during work in a confined space -test the atmosphere in the confined space before entry, and during the time that work is being done in the confined space -complete a confined space entry form, and comply with all required safety precautions |
|
|
Why odor detection of hazardous atmospheres is not reliable? |
some poisonous gases are odorless some poisonous gases deaden the sense of smell lack of oxygen cannot be detected |
|
|
Protective clothing required when handling dry fluoride chemical. |
dust mask goggles gloves |
|
|
Hazard created when dry chlorine is contaminated with organic material such as oil, rags, paper, etc |
fire or explosion |
|
|
Classification of fires; used to determine the type of extinguisher - wood, paper, rubbish, etc - oil, solvents, gasoline, etc - electrical |
Class "A" Class "B" Class "C" |
|
|
The exposure limits for chlorine gas: PEL (permisable exposure limit) REL (recommended exposure limit) TLV (threshold limit value) |
PEL - 1.0 ppm REL - 0.5 ppm TLV - 0.5 ppm |
|
|
The purpose of the fusible plug(s) in chlorine cylinders. |
prevents the rupture or explosion of cylinders due to high pressure |
|
|
Powdered activated carbon fires are of special concern because of these factors. |
there is no detectable flame there is no detectable smoke |
|
|
Hard water scale is usually caused by? |
calcium carbonate CaCO3 |
|
|
What bolt do you adjust on a sludge collector/bar screen? |
vertical capstan |
|
|
What is the most probable cause of a pinging sound from a pump? |
cavitation |
|
|
What is the primary function of couplings on a pump? |
compensate for alignment changes |
|
|
What tools are used to check for parallel and angular alignment of the coupling on a pump or motor? |
a feeler gauge; dial indicator calipers |
|
|
High rate filtration gpm/ft2 for iron and turbidity removal |
4 gpm/ft2 |
|
|
Media depths for dual media filters. |
Total depth - 30 inches Sand - 10 to 12 inches Anthracite - 18 to 20 inches |
|
|
Contact time |
Surface water: 30 minutes minimum Ground water: 15 minutes minimum |
|
|
A chlorine evaporator maintains a water bath at? |
170-180oF |
|
|
How much alkalinity is required for each mg/L of alum added to raw water? |
0.5 mg/L |
|
|
At what temperature does the fusible plug in a gas cylinder melt? |
158-165oF |
|
|
Indigo test |
used to test ozone residual |
|
|
Stratification |
formation, due to temperature, of separate layers in a lake or reservoir |
|
|
A mixture of air and gas is considered hazardous when the mixture exceeds what percentage of the LEL? |
LEL - lower explosive limit 10% |
|
|
Filter disinfection |
Cl2 residual > 25 mg/L after 12 hours contact time, concentration should not be < 15 mg/L |
|
|
When head loss is such that no water will not pass through the filter. |
terminal head loss |
|
|
What is the titrant for amperometric titration? |
PAO - phenlyarsine oxide |
|
|
Membrane CIP (clean-in-place) chemicals |
acids oxidants surfactants |
|
|
What is the usual strength of sodium hypochlorite? |
5 - 15% |
|
|
Why control iron and manganese sMCLs? |
- they stain plumbing fixtures and clothes - they can promote the growth of bacteria which can cause taste and odor problems Mn - 0.05 mg/L Fe - 0.3 mg/L |
|
|
What determines a water plant's classification? |
amount of water produced and processes used in the treatment process |
|
|
What is cavitation? |
the creation of vapor bubbles due to partial vacuum created by incomplete filling of the pump caused by rapid change in velocity of the water can cause pitting |
|
|
Chlorine leaks can be detected by using |
ammonia chlorine detector |
|
|
Most important fact about lubricating equipment is? |
flash point of the lubrication |
|
|
UV disinfection solarization results in? |
decrease in UV effectiveness due to clouding of the glass |
|
|
Alkalinity - chemicals for test - end points - significance |
The capacity of a water to neutralize acids OR a water's capacity to resist a change in pH. - sodium thiosulfate phenolphthalein alkalinity - 8.3 end point methyl orange - 4.5 end point determines efficiency of coagulation |
|
|
95% of all turbidity measurements each month for a 10,000+ population system must be less than or equal to? |
0.3 ntu |
|
|
What is the minimum Cl2 level in the distribution system? |
0.2 mg/L |
|
|
Rotameters measure what? |
chlorine gas flow |
|
|
Apparent color vs true color |
apparent color will filter out true color will not filter out |
|
|
If the pump flows starts backwards on a 3 phase alternating current motor what should be done? |
shutdown and switch any two leads |
|
|
In membrane filtration, what chemical is used as a scale inhibitor? |
sodium hexametaphosphate |
|
|
All dead end's shall have? |
blow off valves or flush mechanisms |
|
|
When both chlorine and polyphosphates are added to a well, which should be added first? |
polyphosphate to sequester the the iron and manganese before the chlorine oxidizes it |
|
|
What are the 4 zones of the sedimentation basin? |
inlet settling sludge outlet |
|
|
What is the smallest of all contaminants? |
virus |
|
|
When chlorine is added to water what two acids are formed? |
hypochlorous acid (HOCl) and hydrochloric acid (HCl) |
|
|
What is a representative sample? |
a sample which contains basically the same constituents as the body of water from which it is taken |
|
|
How long must biological records be maintained? |
5 years |
|
|
Lead and copper records must be kept for how long? |
12 years |
|
|
What causes air binding? |
when air comes out of solution as a result of a decrease in pressure and increase in temperature |
|
|
What is the Piezometric surface? |
height that water rises in a confined aquifer |
|
|
What are the 5 means of preventing backflow (in order of effectiveness)? |
air gap (AG) reduced pressure valve assembly (RPV) double check valve (DCV) pressure vacuum breaker (PVB) atmospheric vacuum breaker (AVB) |
|
|
MCL for trihalomethanes and haloacetic acids 5 |
THM - 0.08 mg/L HAA5 - 0.06 mg/L |
|
|
What is the minimum time and residual for disinfection of a new water line? |
starting residual of 25 mg/L; after 24 hours there must be a detectable residual |
|
|
As a general rule, water pipes should be separated from sewer lines by what distance? |
horizontal - 10 ft vertical - 18 inches with the water line above |
|
|
What is the maximum detention time for a flash mix basin? |
30 seconds |
|
|
What is the detention time for flocculation basins? |
30 minutes with 45 minutes recommended |
|
|
List three ways of removing odors from water. |
1. conventional treatment 2. oxidation 3. adsorption with granular activated carbon compounds |
|
|
What is the area between the scum on the water surface and the sludge on the bottom of a basin? |
supernatant
|
|
|
What is an adit? |
intake structure |
|
|
What is sweep coagulation? |
achieving the desired pH range by overdosing the coagulant |
|
|
Bacteriological sample on a new line must be taken where? |
at each end every 1500 feet at every tee |
|
|
How much chlorine will the sodium thiosulfate in a bacteriological bottle remove? |
up to 10 parts |
|
|
This is a system that pumps water into a sealed tank that also contains compressed air and is typically used by small systems.
|
hydropneumatic system |
|
|
What is water hammer? |
a rapid increase (surge) in pressure in a water system |
|
|
What is a ball valve (curb stop)? |
a device that starts and stops flow by means of a ball with a whole in it |
|
|
Chemical analysis records must be kept for how long? |
10 years |
|
|
What does EOP stand for and how often should it be updated? |
emergency operation plan; should be changed when there is a -change to the water system configuration -and at least every two years |
|
|
Hydrogen sulfide gas can be a problem in what type of water and is recognizable by? |
ground water rotten eggs |
|
|
Ca(OH)2 |
- calcium hydroxide - lime - used for raising the pH of the water |
|
|
NaHCO3 |
- sodium bicarbonate - baking soda - used for pH and alkalinity adjustment for corrosion control - if pH is low and alkalinity is adequate or high, do not use to baking soda to adjust the pH |
|
|
Na2CO3 |
- sodium ash - sodium carbonate - will raise pH |
|
|
NaOH |
- sodium hydroxide - caustic soda - used to raise pH |
|
|
Which laboratory tests are used to monitor the coag/floc process? |
- jar test - pH test - turbidity |
|
|
Record retention time for MOR. |
monthly operations report 5 years |
|
|
Record retention time for SDS. |
safety data sheet 30 years |
|
|
Record retention time for plant SOP. |
standard operating procedure keep updated |
|
|
Record retention time for sanitary surveys. |
10 years |
|
|
Record retention time for storage tank inspection records. |
5 years recommended life of the tank |
|
|
Record retention time for tank maintenance records. |
life of tank |
|
|
Record retention time for turbidity analysis. |
5 years |
|
|
What is a lantern ring? |
a perforated ring placed around the pump shaft in the stuffing box that uses water from the pump discharge to form a liquid seal around the shaft and lubricate the packing |
|
|
Calcium and magnesium will precipitate out of solution at what pHs? |
Ca - 9.4-9.6, when calcium carbonate is formed Mg - 10.8, when magnesium hydroxide (Mg(OH)2) is formed |
|
|
What is a globe valve? |
a small disk is raised and lowered onto a seat to start, stop or throttle flow |
|
|
What is MBAS sMCL? |
0.5 mg/L |
|
|
Iron bacteria is called? |
Gallionella |
|
|
Aeration effectiveness is dependent on? |
air to water ratio |
|
|
During a membrane integrity test, the module is pressurized to approximately ______ psi on from the feed side. |
15 psi |
|
|
In a membrane integrity test, what is maximum loss of head pressure? |
1 psi every 5 minutes |
|
|
Public notification rule |
Tier 1: notify within 24 hours - radio, tv, hand delivery Tier 2: notify within 30 days - mail or direct delivery Tier 3: notify within 1 year - annual notice (CCR) |
|
|
Raw water turbidity must be less than _____ for direct filtration. |
25 ntu |
|
|
If the couplings are not parallel and vertical on a centrifugal pump what problem occurs? |
every rotation throws tremendous extra load on bearings and will shorten the pump lifespan |
|
|
What is the difference between a direct and indirect cross connection? |
direct - subject to backpressure and backsiphonage indirect - subject to backsiphonage only |
|
|
What information is on the lock out/tag out when equipment is locked out? |
signature of person that performed the lock out |
|
|
Who is responsible for communicating with the media and public on water issues? |
designated spokesperson |
|
|
Which type of fire extinguisher should be used on an electrical fire? |
carbon dioxide extinguisher (type C) |
|
|
When draining an in-ground water tank or sedimentation basin for cleaning, what should be considered? |
water table level |
|
|
Which is the best aerator for VOC removal? |
packed tower aerator |
|
|
All community water systems serving 50 or more connections must have ________ of distribution storage based on the past _________ . |
24 hours 12 months |
|
|
List 4 factors that influence disinfection. |
pH temperature contact time concentration of disinfectant |
|
|
In order to make a fluoride "slurry" the water must be softened to _______. |
< 75 mg/L |
|
|
At what temperature and pressure should an autoclave be set? |
121oC and 15 psi |
|
|
What is the sMCL for manganese? |
0.05 mg/L |
|
|
What is the MCL for fluoride? |
4.0 mg/L |
|
|
What is the sMCL for fluoride? |
2.0 mg/L |
|
|
What is the recommended fluoride concentration in Tennessee? |
0.7 mg/L |
|
|
What does a float valve do? |
controls reservoir tank levels by relying on a float to start/stop inflowing water |
|
|
What is temporary hardness? |
- carbonate hardness - hardness that can be removed by boiling or by using lime alone |
|
|
What is permanent hardness? |
- noncarbonate hardness - cannot be removed by heat - must use lime and soda ash to remove |
|
|
What preservative is required for a fluoride sample? |
none is needed |
|
|
All vents on storage tanks shall be screened by? |
#24 mesh non-corrodible steel mesh screen
|
|
|
How does a coagulant aid affect the production of floc? |
- fewer pieces of large floc - less overall floc |
|
|
What are the two types of dry chemical feeders? |
volumetric and gravimetric |
|
|
What is the best method for prevent backflow? |
air gap |
|
|
What is the voltage on a high voltage transformer? |
440 volts or higher |
|
|
What are the categories of membrane filters by pore size in order from largest pore size to smallest? |
microfiltration (MF) ultrafiltration (UF) nanofiltraiton (NF) reverse osmosis (RO) |
|
|
What are wear rings? |
rings placed on the impeller and/or casing of a centrifugal pump to control the amount of water that is allowed to leak from the discharge to the suction side of the pump |
|
|
What is the maximum filtration rate for a high rate filter? |
4.0 gpm/ft2 |
|
|
What does the Langlier Index measure? |
measure of a solution's ability to dissolve or deposit calcium carbonate |
|
|
Plankton causes what in the distribution system? |
taste and odors |
|
|
Odor complaints start at what level? |
5 TON |
|
|
What is TON? |
threshold odor number; used to measure the odor level of a sample |
|
|
What group of algae are usually associated with "blinding filters?" |
diatoms |
|
|
What is the major cause of short circuiting in a sedimentation basin? |
poor inlet baffling |
|
|
What color does the oxidant potassium permanganate turn at its endpoint? |
yellow |
|
|
When air is used to generate ozone, an air dryer should be used to reduce the ? |
nitrous oxide |
|
|
Disposal of sludge from alum and lime to the sewer system can cause? |
sewer blockages |
|
|
What is the minimum and maximum air to water ration for packed tower aerators? |
minimum - 25:1 maximum - 80:1 |
|
|
What is an altitude valve? |
a valve in water storage tanks used to regulate the level by using the water level and pressure to open and close |
|
|
What percent of ozone is produced by ozone generators? |
dry air 1-3% ozone pure oxygen 5-7% ozone |
|
|
sMCL for iron |
0.3 mg/L |
|
|
sMCL for manganese |
0.05 mg/L |
|
|
Action level for lead |
0.015 mg/L |
|
|
Action level for copper |
1.3 mg/L |
|
|
MCL for nitrate |
10.0 mg/L |
|
|
MCL for nitrite |
1.0 mg/L |
|
|
MCL for total nitrate and nitrite |
10.0 mg/L |
|
|
Slaked lime versus unslaked lime |
slaked lime - Ca(OH)2 - increase pH & alkalinity unslaked lime - CaO |
|
|
What does a pressure relief valve do? |
responds to pressure variations at the valve's inlet and opens rapidly when pressure increases to above the setpoints |
|
|
What compound is measured and what titrant is used in the hardness titration |
calcium carbonate CaCO3 titrant - EDTA |
|
|
UV lamp output decreases this much. |
30-40% in the first 7,500 hours
|
|
|
In a dual media filter, what is the grain size for the sand and anthracite coal? |
sand: 0.35 - 0.55 mm anthracite: 0.8 - 1.2 mm |
|
|
What is the purpose of air valves in a system? |
allows air to vent from a water system |
|
|
List 5 properties of chlorine gas. |
1. greenish yellow 2. 2.5 times heavier than air 3. liquid volume expands 460 times in volume to a gas 4. non flammable 5. supports combustion |
|
|
Residual ozone can be measured by what test? |
Indigo test |
|
|
What is zeolite? |
another name for the ion exhcanger |
|
|
What measures the amount of residual of the oxidizing agent ozone? |
iodometric method |
|
|
When supplied with air, ozone generators will produce approximately _______ percent ozone. |
1 to 3% |
|
|
What are 2 reagents that can be used to test for chlorine residual in a colorimetric test? |
DPD ferrous ammonium sulfate (FAS) |
|
|
What is the Van der Waals force? |
natural force that pulls particles of opposite charge together |
|
|
Which chemical increases the bicarbonate alkalinity when added to water? |
sodium bicarbonate (NaHCO3) |
|
|
What does TISAB stand for? |
Total Ionic Strength Adjustment Buffer |
|
|
What test is TISAB used for and what purpose does it serve? |
ties up aluminum and phosphate interferences while testing fluoride with an electrode |
|
|
What problem do down-sloping suction pipes cause in centrifugal pumps? |
air pockets could be draw into the pump and cause an loss of suction |
|
|
List 3 things that indicate the need to backwash. |
filter run time effluent turbidity head loss (terminal head loss=8.0 ft) |
|
|
What is the maximum flow rate for a rapid sand filter used for turbidity removal? |
2.0 gal/min/ft2 |
|
|
What is the maximum flow rate for a rapid sand filter used for iron removal? |
3.0 gal/min/ft2 |
|
|
What is the uniformity coefficient for the media in a rapid sand filter? |
0.35-0.55 mm |
|
|
________ of UV light bulbs causes the glass to lose its ability to transmit light? |
Solarization |
|
|
The rotating set of vanes that force water through the pump is called a(n) ________. |
impeller |
|
|
What are 4 common causes of short filter runs? |
- filter aid overdosing - excessive filtration rates - excessive mudball formation - clogging of the underdrain system |
|
|
What are the 4 categories of contaminants? |
physical - temp, taste, color, odor, turbidity chemical - inorganics, organics, mineral biological - virus, bacteria, protozoans radiological |
|
|
Ozone generators must be supplied with what in addition to electricity? |
Extremely dry air |
|
|
Icing or freezing of a chlorine gas cylinder is caused by what? |
Too high feed rate |
|
|
What piece of equipment will allow a higher feed rate of chlorine gas without causing icing? |
evaporator |
|
|
Which laboratory tests are used to monitor the coagulation process? |
turbidity jar test pH |
|
|
Recarbonation basins are used to stabilize water after _______? |
softening |
|
|
Which chemical is used to soften water through chemical precipitation? |
calcium hydroxide |
|
|
What is the optimal maximum water velocity through pipes under normal operating conditions? |
5 ft/sec |
|
|
The amount of water in a water-bearing formation depends on the _________. |
porosity of the formation |
|
|
What is the primary origin of coliform bacteria in water supply? |
fecal contamination by warm blooded animals |
|
|
What is the primary type of ductile iron pipe joint is used in water systems? |
ball and socket |
|
|
How are slow sand filters cleaned? |
scraping off approximately 1 inch of sand off the top of the filter |
|
|
Wen is the best time to conduct and audio leak survey on a water main? |
nighttime |
|
|
What is the killing or inactivation of pathogenic organisms in water treatment? |
disinfection |
|
|
Carbon dioxide is used to reduce what? |
pH |
|
|
What is the galvanic series? |
a list of metals presented in the order of their corrodibility |
|
|
When lime and sulfuric acid are combined, the reaction forms a _______. |
salt |
|
|
If a 3 phase motor runs backwards when started, what is the best remedy? |
switch any two legs of the circuit |
|
|
Which chemical is used to remove residual chlorine from water? |
sodium thiosulfate (Na2S2O3) |
|
|
When using a saturator to add fluoride to water, what chemical is used and why? |
sodium fluoride (NaF) because it has a constant solubility point |
|
|
Tiny indentations on the shoulder of a bearing or race is called ________. |
brinelling |
|
|
What is the range of wavelengths for a UV system? |
250-265 nm |
|
|
Which repair kit us used for a 150 lb chlorine gas cylinder? |
repair kit A |
|
|
What level in a stratified water source is most likely to incur algal blooms? |
eurotropic (top layer) |
|
|
How can the removal of H2S from water best be accomplished? |
lowering the pH and aeration |
|
|
Turbidity measurements must be reported within _______ days after the end of each month? |
10 days |
|
|
What are the 3 types of water rights? |
riparion appropriative prescriptive |
|
|
How long must individual filter bed turbidity logs be maintained? |
3 years |
|
|
What broth is used in the membrane filter technique when testing for total coliform? |
m-endo |
|
|
What is the time and time temperature for incubating total coliform samples when using the membrane filter technique? |
35oC +/- 0.5 for 24 hours |
|
|
When present, what color will total coliform colonies be when using the membrane filter technique? |
red with a green-gold metallic sheen |
|
|
List 3 physical methods of disinfection. |
UV light heat ultrasonic waves |
|
|
At what temperature does the fusible plug in a chlorine gas cylinder melt? |
158-165oF |
|
|
Which of the following is not considered to be an unethical act? a) accepting bribes b) accepting gifts c) providing false or misleading information d) whistle blowing |
whistleblowing |
|
|
What is the maximum residual disinfectant level (MRDL) for chlorine? |
4.0 mg/L |
|
|
What kind of device can be used to protect against backflow for direct and indirect connection if the water contains a contaminant or a pollutant and is in continuous service? |
reduced pressure backflow prevention assembly (RPBP) |
|
|
What is the MCL for odor? |
3 TON (threshold odor number) |
|
|
What is the sMCL for the contaminant manganese? |
0.05 mg/L |
|
|
How long is the minimum detention time for conventional sedimentation basins used for turbidity removal? |
4 hours |
|
|
What is the main purpose of priming a pump? |
to replace the air inside the pump with water |
|
|
What is the primary health risk of consuming trihalomethanes? |
cancer |
|
|
What main characteristics of a raw water enables blue-green algae to grow? |
presence of nutrients (nitrogen and phosphorus) |
|
|
What type of level sensor is required on an air supply? |
bubbler tube |
|
|
What contributes to the creation of algae blooms? |
increased nutrients in the raw water |
|
|
A 2 inch tap can be made through a saddle on which ductile-iron pipe size? |
6 inch |
|
|
Free chlorine residual times are based on a contact time of ______. |
10 minutes |
|
|
The ability of a water or chemical solution to resist a change in pH is called what? |
buffering capacity |
|
|
What is the odor detection limit for chlorine gas? |
0.3 ppm |
|
|
A foul, rotten egg odor from an aeration unit is an indication that the source water contains what? |
hydrogen sulfide (H2S) |
|
|
How long should a new tank be disinfected before sample is collected for coliform bacteria if using AWWA method 1? |
24 hours |
|
|
The most common water complaints are taste, odor, and __________. |
colored water |
|
|
What do long filter runs tend to cause? |
slime growths |
|
|
What type of pipe is generally use din the construction of very large water mains? |
steel |
|
|
What is a cathode? |
negative pole of an electrolytic cell or system |
|
|
What metals are most likely to leach from household plumbing and cause a health hazard? |
lead and copper |
|
|
Samples collected at regular intervals and combined in equal volume with each other? |
time composite sample |
|
|
A main break may cause a loss of pressure which, in turn, may result in what? |
contamination of the system due to backsiphonage |
|
|
What style of curb box fits loosely over the curb stop and meter? |
arch style |
|
|
What is a schmutzdecke? |
sticky mat of matter that forms on the surface of a slow sand filter |
|
|
Copper sulfate is used in surface water reservoirs to control what? |
algae |
|
|
THMs are usually associated with what? |
water containing organics that has been chlorinated |
|
|
Fire hydrants should generally be set back from the curb at least how far? |
2 feet |
|
|
Chlorine neutralization is necessary when a treated sample is to be analyzed for which contaminant? |
bacteria (coliform and e. coli) |
|
|
What is the name of the pipe that serves as the inlet and outlet to an elevated tank? |
riser |
|
|
A utility annual average day demand is determined by |
dividing the water use for a year by 365 days |
|
|
As water temperature increases, the disinfection action of chlorine will ______. |
increase |
|
|
Push joints should not be used if the following condition exists? |
the pipe must be pushed on at an angle |
|
|
Which substances pose an immediate health threat whenever standards are exceeded? |
coliform and nitrate |
|
|
What is the minimum pipe diameter of a water main form a fire hydrant? |
6 inches |
|
|
True or false: Coagulation, flocculation, and filtration is the best means to remove Giardia lamblia. |
True |
|
|
Which chemical oxidant would be most effective in removing color and controlling taste and odors? |
ozone |
|
|
Excessively hot bearings are most probably due to __________. |
Improper lubrication |
|
|
Which oxidant is a bluish toxic gas with a pungent odor? |
ozone |
|
|
What are the weights of chlorine cylinders both empty and full? |
50 lb cylinders: 250 lb 1 ton cylinder: 3700 lb rail car: 6000 lb |
|
|
Chlorine gas supply line should be replaced how often at a minimum? |
annually |
|
|
pH ranges of alum coagulant |
5.8-8.5 |
|
|
What is nitrification? |
ammonia is transformed to nitrites and then to nitrates |
|
|
How long should new tap records be maintained? |
3 years or until the next sanitary survey |
|
|
The primary purpose of check valves is to prevent what condition? |
water flowing in two directions |
|
|
What is the maximum operating temperature of a mechanical seal? |
160oF or 71oC |
|
|
How often should tanks be professionally inspected? |
every 5 years |
|
|
Insufficient recarbonation during the lime-soda process can cause this filter problem.
|
encrustation of calcium carbonate on the filter media causing growth in the size of the filter grains.
|
|
|
This ion is added to water during zeolite ion exchange softening.
|
Sodium, Na
|
|
|
Manganese greensand iron removal filters are re-generated with this.
|
potassium permanganate, KMnO4
|
|
|
Metaphosphate added to control iron “red water” should be added to the water before this.
|
before the addition of chlorine
|
|
|
This can be used to keep iron and manganese in solution.
|
metaphosphate
|
|
|
Amount of salt required to regenerate a zeolite softener.
|
0.2 – 0.5 lb salt / 1000 grain capacity
|
|
|
Pink water in the effluent of a permanganate / green sand iron treatment system indicates this.
|
the permanganate dose is too high.
|
|
|
Recarbonation of lime-soda soften water is done for this reason.
|
to reduce the scale and incrusting characteristics of the water
|
|
|
Iron in this form causes “red water” problems.
|
ferric iron
|
|
|
Nitrate can be removed from potable water with these methods.
|
ion exchange; reverse osmosis
|
|
|
THMs can be removed from water with this treatment.
|
activated carbon adsorption
|
|
|
This occurs during the regeneration of zeolite ion exchange resin.
|
hardness ions are displaced and sodium ions are replenished on the surface of the resin
|
|
|
Problems that may occur in the operation of an ion exchange softener.
|
insoluble iron and manganese deposits on the resin beds
|
|
|
This softening process does not significantly change the total dissolved solids (TDS) content of the water.
|
ion exchange process; calcium and magnesium ions are simply replaced with sodium ions, which leaves the TDS of the water about the same
|
|
|
Purpose of recarbonation.
|
stop continued precipitation of calcium carbonate
|
|
|
Replacement of granular activated carbon is required at this point.
|
when removal of soluble organic material is inadequate. The adsorption sites on the carbon eventually become filled.
|
|
|
Activated carbon has this effect on chlorine residual.
|
the chlorine residual will be reduced to zero
|
|
|
This causes water to move across a semipermeable membrane during reverse osmosis treatment.
|
water pressure
|
|
|
Bacteria and other microorganisms can cause these problems for reverse osmosis treatment and equipment.
|
membrane fouling; membrane breakdown or deterioration; module plugging
|
|
|
These may be used to raise the pH and/or alkalinity of water.
|
quick lime – CaO; hydrated lime - Ca(OH)2; caustic soday – NaOH; soda ash – Na2CO3
|
|
|
Free or “aggressive”CO2 can cause this problem.
|
corrosion in the distribution system
|
|
|
These can be used to coat distribution system piping to reduce corrosion.
|
silicate compounds; phosphate compounds; calcium carbonate
|
|
|
Optimum pH for the removal of iron and manganese by aeration.
|
8 – 9
|
|
|
Removes these forms of hardness: carbonate hardness; non-carbonate hardness
|
removes carbonate hardness: hydrated lime Ca(OH)2; removes non-carbonate hardness: soda ash Na2CO3
|
|
|
When phosphates are used for iron control, and chlorine is used for disinfection, this is the order to add them to water.
|
add the phosphate before the chlorine
|
|
|
Chlorine formulations used in the water industry.
|
molecular chlorine (gas) Cl2; sodium hypochlorite (liquid solution) NaOCl; calcium hypochlorite (solid) Ca(OCL)2
|
|
|
Type of chlorine residual that appears after the “breakpoint.”
|
free residual chlorine
|
|
|
Major factors that determine the effectiveness of chlorine.
|
concentration of residual chlorine – higher residual = better disinfection; time chlorine is in contact with water – higher contact time = better disinfection; temperature of water - higher temperature = better disinfection; pH of water – low pH = better disinfection; residual type – free residual = better disinfection
|
|
|
Cl2 + H2O =
|
HOCl + HCl hypchlorous acid + hydrochloric acid |
|
|
These can cause chlorine demand.
|
iron, ferrous+2; manganese, Mn+2; hydrogen sulfide, H2S; organic material
|
|
|
HOCL (free chlorine) + NH3 (ammonia) react to form
|
NH2Cl + H2O (monochloramine + water)
|
|
|
Customer complaints about chlorine taste and odor in water are due to small concentrations of this form of chlorine.
|
nitrogen trichloride (tri-chloramine) NCl3
|
|
|
The pH of water has this effect on free residual chlorine.
|
pH below 7.5 – hypochlorous acid present, improved disinfection; pH above 7.5 – hypochlorite ion present, decreased efficiency
|
|
|
Approved disinfectants for public water systems.
|
free chlorine; chloramine; ozone; chlorine dioxide
|
|
|
Methods used to measure chlorine residual.
|
colorimetric (DPD), amperometric titration, starch-iodine titration
|
|
|
Definition of coliform bacteria group.
|
gram negative, rod shaped, non-spore forming, facultative anaerobic and aerobic bacteria able to ferment lactose to gas within 48 hours at 35oC
|
|
|
Types of coliform bacteria.
|
fecal coliform bacteria, that live in the intestine of warm blooded animals; non-fecal coliform bacteria, that live in soil and decaying vegetation
|
|
|
EPA approved methods for determining the presence of coliform bacteria in water.
|
multiple tube fermentation; membrane filter method; presence absence broth; MMO-MUG, colilert
|
|
|
Most common fecal coliform bacteria.
|
E. coli
|
|
|
Media used in the multiple tube fermentation test.
|
presumptive step: lauryl tryptose broth (LTB); confirmed step: brilliant green lactose bile broth (BGLBB)
|
|
|
Meaning of “facultative anaerobe.”
|
able to live in the presence or absence of molecular oxygen
|
|
|
Avoid these when taking bacteriological sample.
|
swivel faucet; water cooler; faucet with aerator (remove aerator); garden hose; hose bib that is too low to the ground or is close to vegetation
|
|
|
Method for disinfecting distribution mains before they are placed into service.
|
disinfect with chlorine at 50 mg/L for 24 hours; at least 25 mg/L must remain after 24 hour period
|
|
|
Pathogenic
|
disease causing
|
|
|
Definition: Disinfection; Sterilzation
|
disinfection – destruction of harmful or undesirable microorganisms; sterilization – complete destruction of all life
|
|
|
Enteric
|
associated with the intestinal tract of animals
|
|
|
Bacteriological samples that require more that 1 hour of transport to the laboratory require this.
|
maintain at approximately 4oC on ice
|
|
|
Free chlorine residual composition.
|
hypochlorous acid (HOCl) + hypochlorite ion (OCl-)
|
|
|
Sample volume needed for coliform bacteria test.
|
100 mL +/-2 mL
|
|
|
These react to form chlorine dioxide.
|
chlorine (Cl2) and sodium chlorite (ClO2)
|
|
|
This indicates a positive fermentation tube during the coliform test.
|
gas in the fermentation tube
|
|
|
Presence of coliform bacteria indicates this. Total coliform bacteria; Fecal coliform bacteria
|
total - bacteria of intestinal or soil/vegetation origin, which may indicate the presence of disease causing microorganisms; fecal - bacteria that originate in the intestinal tract of humans or animal, indicating fecal contamination and may indicate the presence of disease causing microorganisms
|
|
|
Chlorine can have this effect on the taste and odor of water.
|
increase or exaggerate taste and odor due the formation of chlorinated organic compounds
|
|
|
This is destroyed during breakpoint chlorination.
|
combined residual, chloramines
|
|
|
Chlorine dose =
|
demand + residual
|
|
|
The number of bacteriological samples required each month is based on this.
|
population size
|
|
|
Chlorine left after the demand has been met.
|
chlorine residual
|
|
|
Waterborne infectious diseases
|
typhoid; cholera; dysentery; giardiasis; polio; gastroenteritis; cryptosporidiosis
|
|
|
“Rule of thumb” for disinfection power of chlorine residual forms.
|
hypochlorous acid is 100 times more effective than hypochlorite ion; hypochlorous acid is 1000 times more effective than mono chloramine
|
|
|
Advantages of chlorine dioxide over free chlorine.
|
does not react with organic material to form THMs; effective over a wide pH range, including pH above 7.5; effective oxidation of taste and odor compounds
|
|
|
Characteristics of ozone.
|
power disinfectant; does not form stable residual in water; disinfection properties not affected by the pH of water
|
|
|
Bacteria shapes.
|
bacillus “rod”; coccus “sphere”; spirillum “cork screw”
|
|
|
When using solid chlorine tablets to disinfect water mains, the tablet should be placed here.
|
at the top of the pipe
|
|
|
This material reacts with free chlorine to form THMs.
|
organic material, especially humic material from decaying vegetation
|
|
|
Chemicals produced with the reaction of chlorine and ammonia.
|
monochloramine – NH2Cl; di chloramine – NHCl2; nitrogen trichloride – NCl3
|
|
|
Disinfection CT.
|
disinfection concentration (mg/L) x contact time (minutes)
|
|
|
Inactivation requirements for Cryptosporidium; Giardia cysts; Viruses
|
crypto - 2 log inactivation or 99%; giardia – 3 log inactivation of 99.9%; viruses – 4 log inactivation or 99.99%
|
|
|
Characteristics on enteric viruses in water.
|
smallest living organisms; cause certain waterborne infections such as hepatitis A and polio; may be more resistant to disinfection than coliform bacteria
|
|
|
Manner of reporting coliform bacteria in drinking water samples.
|
coliform present or coliform absent
|
|
|
Minimum repeat samples required in response to a positive coliform sample.
|
three, one at the original tap, one at a tap within 5 connections downstream, and one at a tap within 5 connections upstream
|
|
|
Turbidity can have these effects on disinfection.
|
react to produce chlorine demand; “hide” bacteria and other microorganisms from disinfectant action
|
|
|
Method used to disinfect tank or reservoir walls.
|
spray or brush a 100-200 mg/L chlorine solution on the surface of the tank and allow to react for 3 hours
|
|
|
Steps to insure a proper bacteriological sample.
|
allow the tap to run for 1-5 minutes in order to sample from the main; do not rinse the bottle; do not touch any part of the bottle that will come in contact with the sample; do not over-fill the sample bottle, fill to approximately 80% full; transport the sample immediately to the lab; store on ice if longer than 1 hour transport time; properly label the sample
|
|
|
Distribution system bacteriological sampling should be located here.
|
at representative locations throughout the distribution system
|
|
|
Color reaction of chlorine and DPD.
|
pink to red
|
|
|
Minimum free chlorine residual to be maintained throughout the distribution system.
|
0.2 mg/L
|
|
|
Characteristics of chlorine gas.
|
greenish yellow gas; non-flammable, but supports combustion; 2.5 times heavier than air
|
|
|
One volume of liquefied gas chlorine will produce this volume of gas.
|
approximately 460 volumes of gas
|
|
|
Destroys chlorine in a bacteriological sample bottle.
|
sodium thiosulfate Na2S2O3
|
|
|
MCL
|
maximum contaminant level
|
|
|
EPA approved methods of surface water filtration.
|
conventional rapid sand filtration; direct filtration; slow sand filtration; diatomaceous earth
|
|
|
This indicates an “acute” coliform violation.
|
fecal coliform or E. coli positive sample followed by a total coliform positive repeat sample OR; total coliform positive sample followed by a fecal coliform or E. coli positive repeat sample
|
|
|
Contaminants indicated by the following acronyms: SOC; VOC; IOC
|
synthetic organic compounds; volatile organic compounds; inorganic compound
|
|
|
Bacteriological samples that test positive for total coliform bacteria must also be tested for this.
|
E. coli
|
|
|
Examples of inorganic contaminants.
|
cadmium; asbestos; chromium; mercury; fluoride; nitrate/nitrite
|
|
|
Examples of volatile compounds.
|
benzene; ethyl benzene; toluene; xylene
|
|
|
Action level: Lead; Copper
|
lead: 0.015 mg/L or 15 ppb; copper: 1.3 mg/L
|
|
|
Health concern of lead in drinking water.
|
nervous system impairment that can affect the mental development, especially in children
|
|
|
Health concern of nitrate in drinking water.
|
met-emeglobinemia or blue baby syndrome
|
|
|
Vents on covered water storage tanks should be protected in this manner.
|
pointed down and screened
|
|
|
MCL for common water contaminants: THM; Nitrate; Fluoride
|
THM: 0.08 mg/L; Nitrate: 10.0 mg/L; Fluoride: 4 mg/L
|
|
|
Backflow can occur due to these hydraulic conditions.
|
backpressure and backsiphonage
|
|
|
This provides the highest level of backflow protection.
|
air gap separation
|
|
|
Cross connection
|
any actual or potential physical connection between a potable water pipe and pipe, vessel or machine containing a non-potable fluid so that it is possible for the non-potable fluid to enter the potable system by backflow
|
|
|
SDWA definition of a Public Water System. |
a facility that provides water to 15 or more service connections or 25 or more people 60 or more days of the year |
|
|
Conditions that may produce backpressure backflow.
|
elevated piping, for example, a water service to a multi-story building; potable water connection to the discharge side of a pump, for example, a potable interconnection with an irrigation well pump; thermal expansion, for example, a potable water make-up line to a boiler
|
|
|
These can be used to protect potable water from high hazard cross connections.
|
air gap; reduced pressure backflow assembly (RPBA)
|
|
|
These protect against back siphonage only.
|
atmospheric vacuum breaker (AVB); pressure vacuum breaker (PVB)
|
|
|
Plumbing code prohibits this connection.
|
potable water connection to a sewer connected waste
|
|
|
This backflow assembly is for low hazard applications only.
|
double check valve assembly (DCVA)
|
|
|
The surface water treatment rule requires that all cryptosporidium, giardia, and viruses be inactived to this level.
|
crypto: 2 log
giardia: 3 log viruses: 4 log |
|
|
In order to determine the disinfection contact time, it may be necessary to do this to a tank or reservoir.
|
perform a tracer study on the tank or reservoir
|
|
|
These methods can be used to measure the fluoride concentration in drinking water.
|
fluoride specific ion electrode; colorimetric (SPADNS)
|
|
|
These situations require the water supplier to make public notification.
|
an MCL has been exceeded; there has been a sampling or reporting violation; the water system is operating under a variance or waiver
|
|
|
This entity must approve a water system bacteriological sampling plan.
|
approval by the state (TDEC) or other agency having jurisdiction is required
|
|
|
The health concerns of excess fluoride in drinking water.
|
mottled (discolored) teeth; skeletal fluorosis (misshaping) of the bones
|
|
|
What is the MCL for Coliform?
|
more than one positive sample per month (0-40 samples/month); more than 5% positive samples per month (more than 40 sample/month)
|
|
|
Radioactive gas regulated in drinking water.
|
radon
|
|
|
Units of expression used for radioactive contaminants.
|
pico curries / liter, pCi/L
|
|
|
Units of expression used for asbestos in drinking water.
|
million fibers / liter, MFL
|
|
|
Water service to a home or facility where there is an auxiliary water system requires this.
|
a backflow prevention assembly at the service connection to the home or facility
|
|
|
Most of the lead in drinking water comes from this source.
|
corrosion of plumbing materials
|
|
|
Plumbing materials that may contribute lead to drinking water.
|
lead based solder used on copper plumbing; brass or chrome plated brass faucets; galvanized (zinc plated) pipe and fittings; lead service pigtails
|
|
|
Sources of SOC’s in drinking water.
|
industrial solvents; agricultural pesticides
|
|
|
General health concern for VOC’s and SOC’s in drinking water.
|
cancer
|
|
|
Carcinogenic means this.
|
cancer causing
|
|
|
Primacy
|
authority for state to implement and enforce a federal regulation such as the SDWA
|
|
|
Contaminants that are not regulated under the federal SDWA and have no specific health affect.
|
secondary contaminants (secondary MCLs)
|
|
|
Drinking water contaminants regulated because of a health concern.
|
primary drinking water standard
|
|
|
Normal startup amps for a pump motor.
|
3 to 5 times the running amps
|
|
|
Pumping term for the vertical distance from inlet water level to discharge water level.
|
total static head
|
|
|
Slow opening valves on high pressure pumps are important to avoid this problem.
|
water hammer when the pump starts
|
|
|
Define pump shutoff head.
|
the maximum head that can be developed by a centrifugal pump operating at a set speed
|
|
|
Operating a centrifugal pump at or near shut-off for an extended period can cause these problems.
|
pump damage due to overheated water or impeller vibration; very poor pump efficiency
|
|
|
Define pump runout.
|
the maximum flow that can be developed by a centrifugal pump without damaging the pump
|
|
|
Operating a centrifugal pump near runout on the pump curve can cause these problems.
|
motor damage due to excessive amp draw; very poor pump efficiency
|
|
|
Stages or bowls are added to a centrifugal pump to increase this.
|
increase the total head that the pump can produce
|
|
|
Cause of pump cavitation.
|
too high suction lift; plugged suction line; too high pump speed; warm water temperature; throttled suction valve; significant drop in pump discharge head
|
|
|
Air leaking into the suction piping of a centrifugal pump can cause these problems.
|
loss of prime; air lock of the pump
|
|
|
Most common liquid chemical dosing pumps.
|
positive displacement piston pump; positive displacement diaphragm pumps
|
|
|
Materials used to make pump packing.
|
jute, hemp, cotton, teflon, graphite
|
|
|
Lubrication materials used on equipment should conform to this.
|
manufacturer’s specifications
|
|
|
This can protect steel tanks and pipes from galvanic type corrosion.
|
cathodic protection
|
|
|
A gauge on the discharge side of an operating centrifugal pump measures this.
|
dynamic discharge head (static discharge head + discharge friction losses)
|
|
|
A gauge on the suction side of an operating centrifugal pump measures this.
|
dynamic suction head
|
|
|
Function of seal water supplied to the stuffing box of a centrifugal pump.
|
cools packing and shaft; lubricates shaft; flushes grit and other debris away from the shaft
|
|
|
Provides proper tension on pump packing.
|
packing gland, which is adjusted with gland nuts
|
|
|
Pumps that discharge into a common header pump.
|
connected in parallel
|
|
|
When one leg of three phase power to a motor is lost, the pump motor will do this.
|
single phasing
|
|
|
Amp readings when a three phase motor operates under single phase.
|
amperage in one leg is very high, and the amperage on the other two legs is zero
|
|
|
This can be done to change the rotation direction of a three phase pump motor.
|
switch any two of the three motor leads
|
|
|
The function of a pump lantern ring.
|
distribute seal water to the pump packing
|
|
|
“Rule of thumb” for leakage from pump packing.
|
one drip per second for each inch of shaft diameter
|
|
|
Rotating component in a centrifugal pump.
|
impeller
|
|
|
Check valve used to maintain centrifugal pump prime.
|
foot valve
|
|
|
This can be adjusted to change the output of a positive displacement feed pump.
|
pump stroke length; pump speed; pump “on” time interval
|
|
|
Loss of vacuum to a gas cylinder could be caused by these problems.
|
plugged injector head; reduced water flow rate to injector head
|
|
|
“Rule of thumb” for maximum daily removal of chlorine from a cylinder. 150 lb cylinder; 1-ton cylinder
|
approximately ¼ of full tank net weight per 24 hours, or; - 40 lb/day for 150 lb cylinder; 400 lb/day for 1-ton cylinders
|
|
|
Temperature that melts the chlorine cylinder fusible plug.
|
approximately 158oF
|
|
|
Failure of a hypochlorinator could result from this condition.
|
build-up of mineral deposits within the hypochlorinator
|
|
|
Short circuiting in tanks and clarifiers can be reduced with these.
|
baffles, placed in strategic locations
|
|
|
Term for build-up of oxide deposits in steel or iron pipes.
|
tuberculations
|
|
|
Corrosion that occurs due to the contact of dissimilar metals.
|
galvanic corrosion
|
|
|
Method to calibrate the output of a dry chemical feeder.
|
weigh the output of the feeder at various auger speeds, develop a calibration graph from the data collected
|
|
|
Method to calibrate the output of a liquid chemical feeder pump.
|
use a volumetric container on the suction inlet to the solution pump to determine the output at various settings, develop a calibration graph from the data collected
|
|
|
Tubercule formation in distribution system piping can do this to the Hazen and Williams roughness coefficient for the pipe.
|
the Hazen and Williams “C” factor will be lowered
|
|
|
Symptoms of a plugged gas chlorine injector head.
|
the chlorine flow is zero; the chlorine cylinder pressure is normal; the vacuum is low
|
|
|
This material is often used as the “sacrificial anode” in cathodic protection of steel tanks and pipes.
|
magnesium
|
|
|
Problems associated with pump cavitation.
|
pitting damage to impeller and pump volute case; poor pump efficiency
|
|
|
Closing or opening a valve too quickly can cause this problem.
|
water hammer
|
|
|
The principle operation of a reduced pressure backflow assembly.
|
water will not flow from a zone of low pressure to a higher pressure
|
|
|
Amperage draw on a pump motor as the pump discharge valve is closed.
|
the amperage draw will go down
|
|
|
Unit installed in pump stuffing box in a water treatment plant.
|
mechanical seal
|
|
|
This can interfere with accurate dispensing of a dry chemical.
|
moisture build-up in the dry chemical, which interferes with the free flow of the chemical
|
|
|
These conditions may result in loss of filter media. (3)
|
too high backwash rate; air binding in the filter; improper location of backwash troughs
|
|
|
Over-lubrication of pump or motor bearings can result in this.
|
plugged or worn impeller; wrong pump speed; partial plug on suction or discharge side of pump
|
|
|
Fluoridation is primarily fed to prevent caries in |
children |
|
|
Exposure to high concentrations of fluoride causes |
mottling |
|
|
The secondary MCL for fluoride is |
2 mg/L |
|
|
_____ requires water to have a decent buffering capacity as alkalinity. |
Fluorosilicic acid |
|
|
_____ is the chemical formula for sodium fluoride. |
NaF |
|
|
Saturators are used to feed |
sodium fluoride |
|
|
When fluoride is fed using a saturator, a constant concentration of _______ will be produced, regardless of the amount of chemical in the saturator. |
4 g/100 mL |
|
|
A _____ pump cannot be run against a closed valve or pressure will build up until the line bursts. |
positive displacement |
|
|
When determining the proper fluoride feed rate, it is important to take into account |
the natural fluoride content of the water |
|
|
_____ can interfere with the lab testing procedure and give an erroneous high reading for fluoride when using the probe method. |
Aluminum |
|
|
_____ can give erroneous ____ reading of fluoride when using the SPADNS method. |
Polyphosphates; high |
|
|
The level of sodium fluoride crystals in a feeder should be kept at least |
6 inches |
|
|
_____ is the only type of fluoride that should be used in a down flow saturator. |
Crystalline NaF |
|
|
Lead leaches easily into the water from pipes especially when connected to _____. |
copper |
|
|
An electrolyte is |
a conducting solution |
|
|
The Lead and Copper rule is governed by the |
USEPA |
|
|
A first draw sample must be taken after the water has sat in the customer's line for |
6 hours |
|
|
The action level for copper is |
1.3 mg/L |
|
|
Action levels are based off of |
state mandates |
|
|
As dissolved oxygen levels increase |
corrosion increases |
|
|
For lime to be fed, the alkalinity must be at least |
40 mg/L as CaCO3 |
|
|
A major safety concern for unslaked lime is |
contact with moisture resulting in extreme heat |
|
|
Red water is caused by |
high iron concentrations in the water |
|
|
1 mg/L of hydrated lime will produce |
1.35 mg/L of CaCO3 |
|
|
Chemical precipitation is |
coming out of solution into the solid form |
|
|
The MCL for iron is |
there is no MCL for iron |
|
|
The secondary MCL for manganese is |
0.05 mg/L |
|
|
Ferric oxide is |
oxidized Fe |
|
|
The oxidized state of manganese is |
manganese hydroxide |
|
|
_____ is the first step in iron/manganese removal. |
Oxidation |
|
|
If the iron level is below _____, then the water can go straight to the filters without sedimentation for iron removal. |
5 ppm |
|
|
Manganese greensand filters are recharged with _____ for _____. |
KMnO4; 1 hour |
|
|
The flow rate of a greensand filter is |
2-3 gpm/ft2 |
|
|
If chlorine is used to recharge a greensand filter, the pH must be below |
9 |
|
|
Solubility of sodium fluorosilicate will _____ as water temperature decreases. |
decrease |
|
|
If water hardness is greater than _____ when using a fluoride saturator, the water must be softened. |
75 mg/L as CaCO3 |
|
|
What does TISAB stand for? |
Total Ionic Strength Adjustment Buffer |
|
|
TISAB contains what chemical to sequester metals that may interfere with fluoride probe readings? |
CDTA |
|
|
What is the action level for lead? |
0.015 mg/L |
|
|
What is the action level for copper? |
1.3 mg/L |
|
|
First draw samples should be collected at ________ in the distribution system. |
high risk sites |
|
|
The connection of two or more dissimilar metals in an electrolyte such as water is referred to as _____. |
galvanic corrosion |
|
|
How does water velocity affect the aggressiveness of water? |
High velocity will increase the agressiveness (higher DO) Lower velocities lead to water stagnation and corrosion. |
|
|
Iron bacteria is also called _____. |
Gallionella |
|
|
Sulfate reducing bacteria in a system can produce ______ and ______. |
iron sulfide (Fe2S2) hydrogen sulfide (H2S) |
|
|
_____ can be used with lime if more alkalinity is needed. |
Soda ash |
|
|
To create a coating of calcium carbonate on distribution mains can be accomplished by adjusting the pH to _________ the saturation point of CaCO3. |
just above |
|
|
Polyphosphates inhibit corrosion by ______. |
sequestering |
|
|
Orthophosphates will create a ______ in a system. |
pipe coating |
|
|
What is unslaked lime? |
Quicklime (CaO) contact with moisture will start slaking process and generate tremendous heat |
|
|
What is slaked lime? |
hydrated lime (Ca(OH)2) best fed using dry chemical feeder |
|
|
What is soda ash? |
sodium carbonate (Na2CO3) will generate carbon dioxide when joined with acids |
|
|
What is baking powder? |
sodium bicarbonate (NaHCO3) |
|
|
What is caustic soda? |
sodium hydroxide (NaOH) |
|
|
The difference between direct filtration and conventional filtration is |
direct filtration does not utilize sedimentation |
|
|
Specific gravity is |
the ratio of a substance's density in comparison to the density of an equal mass of water |
|
|
Specific gravity is most closely linked to |
filter media stratification |
|
|
The most important factor in filtration is |
adsorption |
|
|
Deep bed gravity single media filters range in depth from |
48-72 inches |
|
|
_____ filters are cleaned by scraping off the top inch of media. |
Slow sand |
|
|
Diatomaceous earth filter media is made up of |
fossilized algae |
|
|
A major disadvantage of pressure filtration is |
inability to see inside the filter |
|
|
_____ filters do not use a chemical pretreatment. |
Slow sand |
|
|
The _____ is a biologically active sticky mat on top of a filter. |
schmutzdecke |
|
|
_____ filter media is fed into the water creating a slurry that is collected and screened on porous walls. |
DE (diatomaceous earth) |
|
|
Filter run times depend primarily on |
influent water quality and filtration rate |
|
|
A properly operating filter should produce a UFRV of |
5000 (unit filter run volume) |
|
|
Mudball formation can be prevented by |
proper backflow rates and agitation |
|
|
Filter stratification is created and maintained by |
specific gravity |
|
|
Air binding is caused by |
low filter bed pressure |
|
|
The average filtration rate of a slow sand filter is |
0.5 gpm/ft2 |
|
|
Conventional rapid sand filters have an average filtration rate of |
2 gpm/ft2 |
|
|
A sand boil is |
an area in the filter where the media has been displaced |
|
|
Filters that are air binded must be backwashed carefully to prevent |
media loss |
|
|
Coagulant is added _____ when using in-line treatment. |
right before the filter |
|
|
Disinfection is |
the destruction or inactivation of pathogenic organisms. |
|
|
The chlorine residual in the distribution system should at not time fall outside the levels of |
0.2 - 4.0 mg/L |
|
|
The majority of all pathogenic microbes originate from |
the digestive tract of warm blooded mammals. |
|
|
The MCL for pathogenic organisms |
there is no MCL for pathogenic organisms |
|
|
Coliform bacteria are |
a commonly found group of bacteria |
|
|
Cholera is a disease caused by pathogenic |
bacteria |
|
|
_____ are smallest biological contaminants. |
bacteria |
|
|
_____ is a physical method of disinfection. |
UV light |
|
|
There is a mandatory _____ removal for cryptosporidium. |
4 log |
|
|
There is a mandatory _____ removal for giardia. |
3 log |
|
|
Boiling water is a |
disinfection method. |
|
|
UV light alone provides_____ crypto removal. |
2-3 log |
|
|
The contact time needed for UV light is |
instant |
|
|
The specs for an autoclave are |
121 degrees celsius, 15 psi, 15-20 minutes |
|
|
_____ is the most effective chemical to use against crypto. |
Ozone |
|
|
_____ is a very effective pre-treatment chemical used to oxidize metals, algae control, and zebra muscles. |
KMnO4 |
|
|
Ozone generation requires |
extremely dry air |
|
|
KMnO4, when used in conjunction with Cl2, will |
lower your DBPs |
|
|
O3 (ozone) gas is |
corrosive |
|
|
BrO3 is |
a carcinogenic compound formed from ozone and bromide |
|
|
The dew point of an ozone generator is |
-51 degrees celsius |
|
|
If air is the feed gas for an ozone generator, then |
1-3% O3 will be produced |
|
|
The purpose of the water circling and ozone generator is |
to cool the generator |
|
|
Gerimcical UV is between the wavelength? |
200-280 nm |
|
|
Chlorine gas is |
2.5 times as dense as air |
|
|
_____ and_____ are the most important factors in chlorination. |
Contact time and concentration |
|
|
A well must be disinfect for_____ with free chlorine. |
24 hrs at 25 mg/L
|
|
|
The two most common chlorine residuals are |
HOCl and OCl- |
|
|
At pH above 8.5, all HOCl turns into |
OCl- |
|
|
The basic formula for feeding chlorine gas is |
Cl2 + H2O --> HOCl + HCl |
|
|
Chlorate is |
produced by chlorine dioxide |
|
|
NaOH is |
sodium hydroxide |
|
|
The most accurate method of measuring chlorine residual is |
amperometric titration |
|
|
The maximum withdrawal rate of a chlorine container requiring an emergency repair kit A is |
42 lb/day |
|
|
If a pin leak is located in a ton chlorine cylinder, then |
the leak should be rotated to the top |
|
|
A 150 lb chlorine cylinder should be moved by |
a hand cart with a chain |
|
|
Chlorine gas can be detected by smell at |
0.3 ppm |
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Chlorine leaks can be located by |
using 26% ammonia |
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Hospitals must be notified when using |
chlorine dioxide and chloramines |
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The wrench used to open a chlorine valve should never be above |
6 inches long |
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Fusible plugs on chlorine gas cylinders are designed to melt at |
70-74 degrees celsius |
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NH3 is the chemical formula for |
ammonia |
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The most common place for a chlorine leak to occur is |
the pressurized chlorine supply line |
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If chlorine gas is pulled too quickly from the cylinder |
freezing of the lines can occur |
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SCBA with a 30 minute air pack give a low pressure alarm when |
5 minutes of air is remaining |
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SCBAs must be certified by |
NIOSH |
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A minimum of _____ operators are required to change a chlorine tank. |
2 |
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Residual disinfectant concentration cannot be less than 0.2 mg/L for more than |
4 hours |
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The chlorine residual cannot be lower than 0.2 mg/L in more than _____ of all samples collected in 2 consecutive months. |
95% |
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The lowest chlorine residual must be recorded |
daily |
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Chlorine gas _____ the pH of water. |
lowers |
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FAS stands for |
ferrous ammonium sulfate |
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_____ is used as the titrant in the DPD titrimetric method to test for chlorine residual. |
FAS |
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Chlorine dioxide (ClO2) can cause taste and odor complaints at above |
0.4 - 0.5 mg/L |
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Sodium hypochlorite and calcium hypochlorite will _____ pH. |
raise |
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What is an evaporator on a chlorine gas cylinder? |
Heats (170-180F)the chlorine liquid to a gas to increase the feed rate and prevent freezing |
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How do you fix a hypochlorinater that has a line clogged with calcium carbonate? |
pump 5% HCL (muriatic acid) through the system |
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Drawing water from the top of a container without stirring up sediment at the bottom is known as |
decanting |
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_____ is the largest of the four zones in a sedimentation basin. |
Settling zone |
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A self-cleaning tube settler will be angled at |
50-60 degrees |
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Chemicals are "recycled" in this type of sedimentation basin. |
solids contact basin |
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The main cause of short circuiting is |
inlet baffling |
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The collection trough for water after sedimentation is known as |
launder |
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A _____ is used to determine if short circuiting is occurring. |
dye test |
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DAF is effective for |
algae control |
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What percentage of clarifier water is recycled and super saturated with a gas and introduced in the DAF process? |
10% |
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Plate and tube settlers should be angled a minimum of |
7 degrees |
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_____ are especially prone to disruption when sudden changes occur in source water. |
Up-flow clarifiers |
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_____ is the feed gas in a DAF system when oils are being removed. |
Nitrogen |
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Which is a physical method of slime removal? |
dewatering |
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_____ is the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface. |
Adsorption |
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DAF will provide a |
2 log removal of crypto |
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The weir overflow rate of an up-flow clarifier is |
greater than or equal to 10 gpm/ft of weir |
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Detention time equals |
volume/flow |
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The minimum recommended detention time of a conventional sedimentation basin is |
4 hours |
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Pulsators are used for |
low turbidity, high color water |
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Shallow depth plates should be installed at |
45 degrees |
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The goal of basin inlets is to |
reduce velocity and provide even distribution |
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The goal of DAF is to provide |
small pin-sized floc |
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Alum sludge concentrations normally range from |
0.25-10% |
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Drying beds and lagoons for alum sludge provide a solids content of |
30-50% |
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Aeration is normally the |
first step in the treatment process |
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Effective gas exchange in aeration is a result |
high surface area |
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CO2 is most soluble in water at temps of |
68 degrees F |
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Carbon dioxide will keep iron in solution at concentrations of |
5-15 mg/L |
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_____ can turn silverware black. |
H2S |
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CH4 is the chemical formula for |
methane |
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0.1% by volume in air can kill in 30 minutes
|
H2S |
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This can cause a garlic taste in water. |
methane |
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_____ is formed by the breakdown of uranium. |
radon |
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_____ is an example of an air into water aerator. |
Diffuser |
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The minimum air to water ratio of a packed tower aerator is |
25:1 |
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Hydrogen sulfide is best removed at a pH of |
less than 6 |
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Clogging of blowers is most commonly caused by |
over lubrication |
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Hydrogen sulfide is explosive at |
4.3% |
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The MWCO (molecular weight cutoff) is measured in |
Daltons |
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High pressures and temperatures is likely to cause membranes to |
compact |
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The operating pressure of microfiltration membranes is |
5-30 psi |
|
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The inside fiber is known as the |
lumen |
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The MWCO for ultrafiltration is |
80,000 - 100,000 |
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Magnetic ion exchange is used to remove |
TOCs |
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One milligram of calcium removed in the ion exchange process will increase the TDS |
0.15 mg/L |
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Hardness is measured in _____ in ion exchange softening. |
grains per gallon (gpg) |
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_____ are most common in cation exchange. |
Strong acid resins |
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Weak acid resins operate a pH of |
4 |
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Strong base resins operate over |
entire pH range |
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_____ or_____ salt is used for ion exchange regeneration. |
Rock; pellet |
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_____ is a major problem in the ion exchange process and should be removed before treatment. |
Iron |
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Any person in charge of a water treatment plant, wastewater, distribution or collection must be certified_____. |
in a grade equal to or greater than the grade of the plant/system/facility that they are running. |
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A system must notify the Division of Water Supply within _____ of losing its certified operator in direct charge. |
30 days |
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_____ is responsible for keeping the state updated on a certified operator's current address. |
The operator |
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An operator found guilty of falsifying records can face |
revocation of license for 5 years and civil penalties |
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An operator found guilty of negligence/failure to use reasonable judgement can face |
revocation of license for 1 year and possible civil penalties |
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In the event of an emergency, _____ should address the public regarding problems. |
a designated spokesperson |
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The addition of water to a strong acid can cause |
rapid generation of heat |
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The incubator for total coliform and e. coli tests should be kept at a constant |
35 degrees C |
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The membrane filtration method is a_____ hour test. |
24 |
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All community water systems must maintain a positive pressure of _____. |
20 psi |
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After a bacteriological sample tests positive for coliform bacteria, a repeat set of samples must be collected within _____. |
24 hours |
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A class C fire is described as |
energized electrical |
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What type of fire extinguisher would you use on an electrical breaker? |
CO2 |
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A paper fire would require what kind of fire extinguisher? |
Type A |
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A methane (CH4) gas fire would be classified as |
class B |
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What is the immediate action upon noticing the small of chlorine in a chlorine room? |
leave the room immediately |
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The only reliable method of determining Cl remaining in storage is |
weight |
|
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The most common instrument used to determine a flow of gas is the |
rotameter |
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The density of the chemical being fed must be known when using this type of dry feeder. |
volumetric |
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The desired change in color being reached in a titration test is known as |
the end point |
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The only reliable method of determining Cl remaining in storage is |
weight |
