Chapter 5 - Water Treatment & Purification Flashcards
(188 cards)
1
Q
What are water sources developed for military use referenced as?
A
Water points.
2
Q
What are examples of surface water?
A
Streams, lakes and rivers.
3
Q
What does the amount of precipitation, the size of the drain area, geology, ground surface, evaporation, temperature, typography, and artificial controls determine?
A
This determines the amount of water that collects in any surface source.
4
Q
How many gallons of water are in a cubic foot?
A
7.5 gallons of water.
5
Q
How many gallons of water are in a cubic foot that has to account for error and stream measurement?
A
6.4 gallons.
6
Q
What formula would you use to calculate a flowing streams quantity of water in gallons per minute?
A
Q= 6.4 x A x V
7
Q
What does the Q stand for in the formula that determines GPM in a flowing stream?
A
Q = quantity of water in gallons per minute.
8
Q
What does the A stand for in the formula that determines GPM in a flowing stream?
A
A= Area of the stream.
9
Q
How would you obtain the area (A) of a stream in square feet?
A
By multiplying the width times the average depth of the stream.
10
Q
What does the V stand for in the formula that determines GPM in a flowing stream?
A
The velocity of the stream in feet per minute.
11
Q
How would you obtain the velocity (V) of the stream and feet per minute?
A
By measuring the time it takes for a floating object to travel a known distance, such as a twig flowing at 13.3 ft./m.
12
Q
A stream having an average depth of 2 feet, a width of 16 feet, and a twig is noted to flow at 13.3 ft./m. Calculate the quantity of water and gallons per minute flowing in the stream.
A
Q= 6.4 x A x V Q= 6.4 x (2x16) x 13.3 Q= 6.4 x 32 x 13.3 Q= 2,723.84 gpm
13
Q
What are three factors you must consider when selecting a water source?
A
Quantity, quality, and reliability.
14
Q
What formula would you use to calculate the quantity of water in a lake or pond having little or no run off?
A
Q= A x D x 7.5
15
Q
What does the A stand for in the formula that determines GPM in a Lake or pond having little or no run off?
A
Surface area.
16
Q
What does the D stand for in the formula that determines GPM in a Lake or pond having little or no run off?
A
Average depth.
17
Q
How many gallons per cubic feet are inside of a pond or lake that has little to no run off?
A
7.5 gallons per cubic foot.
18
Q
What does the Q stand for in the formula that determines GPM in a Lake or pond that has little to no run off?
A
Q = quantity of water in gallons per minute.
19
Q
If a pond or lake has an average depth of 7 feet and a surface area of 2864 ft.² how many gallons is inside of this pond or lake?
A
Q= A x D x 7.5 Q= 2,864 x 7 x 7.5 Q= 150,360 gallons
20
Q
What bodies of water are usually located within the water table?
A
Lakes and ponds.
21
Q
How would you calculate the quantity of water that can be supplied from newly constructed or existing wells?
A
By making a drawdown test.
22
Q
When conducting a drawdown test how many feet would you draw down the static water level to record it’s recovery time?
A
1 to 2 feet.
23
Q
What is a static water level inside of a well?
A
It’s when the level inside of the well is the same level as the water table.
24
Q
What is the water table?
A
It is the water beneath the ground.
25
How would you obtain a static water level?
By measuring the distance of the ground surface to the static water level.
26
If a water level in a well is 25 feet below ground what is the static water level for this well?
The static water level for this well is 25 feet.
27
When a water well is pumping for several hours at a constant rate it stabilizes itself in a lower position what is this called?
This is called the pumping level.
28
What is another name for the pumping level?
Dynamic water level.
29
When water beneath the ground is lowered by pumping what is this distance called?
The distance the water is lowered by pumping is called the drawdown.
30
What is the drawdown inside of a well?
It is the difference between the static water level and the pumping level.
31
When drawdown occurs inside of a well resulting from pumping what does this do to the water pressure in the well?
It lowers the water pressure inside of the wall.
32
If water pressure is lowered inside of a well what happens to the surrounding water beer in formation pressure?
It retains its original pressure.
33
When the water bearing formation pressure is different from the water pressure inside of the well what does this result in?
It makes water flow out of the pores from the formation into the well.
34
What is a term used to describe the characteristics of a porous material?
Permeability.
35
What are the factors that would affect the rate of flow within a water well?
The frictional resistance to flow developed within the aquifer formation a.k.a. the permeability of the formation to give out water.
36
What factor affects the quantity of water a formation can supply to a water well?
The amount of water and aquifer can supply is directly proportional to the permeability of the formation (aquifer).
37
What does the volume of water pumped per minute or per hour, the depth to the static water level before pumping is started, the depth to the pumping level at one or more constant rates of pumping, the recovery of the water level after pumping is stopped, and the length of time the well is pumped at each rate provide you with when working with waterwells?
The measurements that should be made in testing water wells for its hydraulic characteristics.
38
What should the pump and power unit used for testing a well be capable of?
Continuous operation at a constant and variable-rate a pump which for a period of over 24 hours.
39
At a minimum how long should pumping tests of water well occur?
The test should run at least 24 hours.
40
How would you be able to verify the adequacy of a water well formation?
By running longer pumping tests, up to several weeks in duration.
41
By ensuring that the pump will operate at a rate that will case only about 50% of the maximum possible drawdown what are you doing?
You are determining the safe yield of a well.
42
Inside of a water well the drawdown should not exceed a point of how many feet above the top most screen slot?
5 feet.
43
What includes initial static water levels, pumping right at least every hour, drawdown data at least every hour and rate of recovery?
The complete water well test report.
44
What is the safe pumping yield for water wells?
A withdrawal rate that doesn't cause a lowering of the water table and goes no more than 50% of the maximum drawdown.
45
When using a catch tank to record gallons per minute from water wells how many minutes at a minimum should just catch tank be rated for?
At least two minutes.
46
When using a catch tank with a capacity of storing two minutes of water to record gallons per minute from a water well what is the limitation to this method?
Since attached tank is so small you can only use it for small wells.
47
What instrument offers a definite advantage and measuring water being pumped from water well?
Water meters.
48
What instrument has the capability of recording the total discharge for any individual phase of a drawdown test?
Water meters.
49
What is the most accurate way to measure depth to the static level and to the pumping level in a water well?
With chalked tape.
50
How many feet of chalked tape should be submerged when measuring the depth of the static level to the pumping level inside of a water well?
1 to 2 feet of the tape is submerged.
51
What are you trying to find when you divide the water wells yield or discharge in gallons per minute divided by the drawdown and feet?
You're trying to find the specific capacity of the well.
52
What is more dangerous to health when found in water, suspended or dissolved impurities?
Suspended impurities are usually more dangerous to health.
53
Mineral matter, disease organisms, salt, bacteria and algae are all examples of what inside of water?
Suspended impurities.
54
How would you find an impurity in the water that cannot be seen by the naked guy?
By conducting laboratory tests only.
55
What calcium and magnesium based impurities cause alkalinity hardness in water?
Bicarbonate
| Carbonate.
56
What calcium and magnesium based impurities cause hardness within water?
Sulfate.
57
What calcium and magnesium based impurities cause harness that is corrosive to boilers?
Chloride.
58
What sodium based impurities cause alkalinity within water?
Bicarbonate
| Carbonate.
59
What impurity causes foaming in steam boilers?
Sulfate.
60
What impurity inside of water causes mottled enamel teeth?
Fluoride.
61
What dissolved in purity causes a salty taste inside of water?
Chloride.
62
What dissolved in purity causes Redwater and encrusts on metals?
Iron.
63
What dissolved impurity causes black or brown water?
Manganese.
64
What does all the purity causes color and acidity?
Vegetable dye.
65
What dissolved gas based impurity inside of water causes corrosion of metals?
Oxygen.
66
What gas based impurity cause acidity and corrosion of metals?
Carbon dioxide.
67
What dissolved gas impurity causes odor, acidity and the corrosion of metals?
Hydrogen sulfide.
68
What gas based impurity has no effect within water?
Nitrogen.
69
Why would you forward water samples to a laboratory?
For complete mineral or bacteriological analysis.
70
How would you know what variations to expect at water sources?
By studying the hydrological data.
71
What may control the amount of water flowing and the rate of flow within a water well?
Geological layers.
72
What level is the title to ground and surface water in the United States usually regulated at?
The state level.
73
What type of waters are under federal control?
Navigable waters having interstate traffic.
74
A total of how many gallons per minute or flowing stream that is 10 feet wide and has an average depth of 3 feet when the water is flowing at a velocity of 15 ft./m?
```
Q= A x V x 6.4
Q= (10x3) x 15 x 6.4
Q= 2,880 GPM
```
75
What sources are used to increase the quantity and quality of water?
Dams, floats, galleries, and similar improvements may be used.
76
True or false? When developing a water source all intake hoses and pipes should be equipped with an intake strainer regardless of the clearness or water source.
True.
77
When working with suction lines and strainers how would you prevent loss of prime, punctured or kinked lines, and damage strangers?
By properly anchoring them.
78
How many inches should you place a strainer underneath the water level?
4 inches.
79
What is a cause for losing prime when pumping liquids with pumps?
Air getting into the suction line.
80
What are you trying to accomplish when you dam up streams or rivers, when you use the flow from streams, when you pump directly from surface dreams, by collecting water from the roofs or buildings, by providing catchment areas for the collection of rainwater into specially constructed cisterns, by solar distillation, by power distillations, by freezing and by getting electrodialysis?
You're trying to collect water supply from surface sources.
81
For normal field water supply what is the most accessible type of water source?
Surface water.
82
When you place an intake strainer into a water source what is the proper way to place it?
By securing it with a rock or if the water source a shallow than securing the intake pipe onto a post or pile.
83
When selecting a water source what would you do if the water source is so shallow that the intake screen isn't covered by at least 4 inches of water?
You should dig a pit into the water source and secure the intake strainer with a rock or board at the bottom of the pit.
84
What should you do if you dig a pit into a water source that has a lot of clay or silt at the bottom where your placing your intake strainer?
You should line your intake strainer with gravel, This prevents dirt from entering the line.
85
How would you be able to raise the water level in small streams so that the intake strainer is covered by at least 4 inches of water?
By building a dam.
86
When would you want to build a wing or baffle damn to protect intake screen without impounding water?
In swiftly flowing streams and water sources.
87
If the quality of the water varies across the width of the source or if the water isn't deep enough near the banks to cover the intake strainer how would you support the intake strainer to get to those parts of the water that you want to collect?
You would support the intake strainer house by using floats.
88
When supporting an intake strainer hose what can you use to make floats?
Floats can be made of logs, lumbar, sealed cans, or empty fuel drums.
89
What type of advantage would you gain when using floats to support the hose of your intake system?
The intake strainer can be adjusted vertically with ease.
90
How would you improve the quality of water from muddy streams?
By digging a trench around the bank of that stream deep enough to where you can see the water, placing your strainer inside the trench then surrounding it with gravel. This is (aka a gallery)
91
What way can you reduce the use of chemicals to coagulate water sources, reduce backwashing the filter, and obtain higher water quality when collecting water through your intake line?
By building galleries. (A trench filled with gravel alongside the water source that is deep enough to collect water running off from the source).
92
The zone of soil moisture, the zone of aeration/percolation beneath the soil or, the zone of saturation are all examples of what?
The three zones were moisture is held beneath the surface of the earth.
93
In groundwater development this is the zone where water is temporarily held in pore spaces by capillary action or other soil conditions.
This is the zone of soil moisture.
94
In groundwater development this is the zone where both water and air are present in the pore spaces.
The zone of aeration/percolation beneath the soil layer.
95
In groundwater development this is the zone were all spaces are filled with water.
This is the zone of saturation.
96
If water quality (not pressure) is coming out very hard inside of an underground water supply what may be the cause of this?
Mineral deposits within the underground water source that contain water hardeners. I.E. Calcium.
97
What is issued and 2 inch diameters and 54 inch lengths?
Well points.
98
When driving a well into the ground what would you place over the threads?
A drive cap.
99
When you're driving a well into the ground how long are each sections of pipe?
5 feet long.
100
How would you know when you're done driving in sections of pipe when making a well?
You would drive it until the screen is well within the water bearing media.
101
What is the practical limit of suction left for pumps issued with field equipment?
22 to 25 feet at sea level.
102
What should be used within the suction limit lift or 22 to 25 feet below the position of the pump?
A suction lift pump.
103
At 5000 feet above sea level what is the practical limit of suction lift?
20 feet.
104
What would you do to make sure that a suction lift pump for water wells creates a partial vacuum in the suction line?
You would make sure that the line is absolutely airtight for the pump to function properly.
105
How many gallons of water per minute would you need if you were using springs as a source of field water?
20 gallons per minute or more.
106
True or false? Digging is a more positive and more economical method of developing a spring than blasting.
True.
107
Should you develop thermal (Hot) Springs?
No because the waters are highly mineralized.
108
Why shouldn't you ventilate spring structures?
To keep the spring from becoming contaminated.
109
What are the five types of Wells?
Dug, bored, driven, jetted, drilled.
110
In the event of chemical, biological, and radiological operations would groundwater become contaminated by airborne or surface dissemination?
Groundwater would not be affected but surface water would be.
111
What variables contribute to the rise and the lowering of the groundwater table?
Rainfall, tides and pumping right from the wells.
112
What type of well is seldom less than 3 feet in diameter, excavated with hand tools, lined with brick, stone, steel, wood cribbing, or tile and is easily polluted by surface wash.
Dug Wells.
113
What type of well has a depth that ranges from 25 to 60 feet, does not cave and is constructed in soft water bearing formations?
Bored wells.
114
What type of well has an inner tube, outer tube and uses a power driven pump with suitable house attachments supply continuous water pressure during drilling?
Jetted Wells.
115
What type of well usually ranges in diameter from 1 1/4, 2 inches, and 4 inches?
A driven well.
116
What type of well has a point that consists of a perforated pipe with a mild steal point at its lower level to break through pebbles or thin layers of hard material?
Driven well.
117
What limits the depth of a driven well?
Formations found in the ground and the type of pump being used.
118
When developing small driven wells with suction pumps how many feet must the ground water level be within the surface?
Within 25 feet.
119
When developing driven wells with small, self priming, centrifugal pumps the lift must be less then how many feet?
It must be less than 25 feet.
120
If you're developing a driven well with 2 inch or larger pipes what would you use to lift the water from a greater depth?
You would use a cylinder type pump near the water level.
121
What type of well is suitable in soft, unconsolidated, alluvial deposits?
Jetted Wells.
122
When developing a well what should you clear around the pump screen?
Fine sediment.
123
What are the two methods of drilling wells?
Hydraulic rotary and cable tool percussion.
124
When collecting water how far should a catchment area be located away from any source of subsurface contamination and sources of pollution?
At least 100 feet away.
125
What does rainwater absorb as it hits the earth?
Dust and gases such as carbon dioxide and oxygen.
126
What would you use it for location has water that is hard to get or polluted?
Water barges or mobile tanks.
127
Where can water barges or mobile tanks be filled from?
They can be filled from ships, tank trucks or other well points located some distance away.
128
Why would you use ice over snow as a water source?
Because ice has a higher volume of water contained within it.
129
How many cubic feet of snow is required to yield 1 ft.³ of water?
5 ft.³.
130
In an emergency how would you injest snow to prevent chapped or cut lips?
By placing it in the mouth rather than sucking it.
131
Factors such as surf action, salt water corrosion, suspended sent and silt in the water, living organisms, surface oil along beaches, and the rise and fall of the water level with the tides help you in developing what?
Sea water sources.
132
When would you be able to use the same builder is fresh water surface and takes on salt water?
When the equipment is located on sheltered base, harbors, lagoons or estuaries.
133
What type of Wells would you use when collecting water on beaches?
Driven, jetted and beach Wells.
134
What would you use to collect water if you don't have the time or resources to build wells on beaches?
You would use offshore intakes.
135
What are the types of offshore intakes?
Rigid pipe and float type.
136
Where should you position rigid pipe and float type offshore intakes inside of the water?
They should be located in deepwater beyond the surf.
137
How should you position rigid pipe and float type offshore intakes?
Vertically and off of the bottom but still beneath the water surface at low tide.
138
How would you support secure the position of rigid pipe intakes?
On timber supports by piling or riprap.
139
What would you use to connect the rigid pipe on the seabottom to the pipe supported beneath the float?
A rubber section hose.
140
How would you detect biological contamination?
By testing for chloroform organisms.
141
How would you detect radiological contamination?
By using radiac equipment and by conducting special laboratory field tests.
142
What type of impurity in the water is either suspended or dissolved?
Physical impurities.
143
Which is more dangerous to health suspended or dissolved physical impurities?
Suspended.
144
This type of physical on impurity includes mineral matter, disease organisms, salt, bacteria, and algae.
Suspended impurities.
145
What are the most important physical impurity characteristics?
Turbidity, color, odor, taste, and temperature.
146
How would you determine by looking if there's a chemical agent physical impurity inside of the water?
Dead or mottled vegetation and presence of dead fish frogs and so forth.
147
You would use copper sulfate, chlorine, or activated carbon to prevent this from forming in raw water supply points.
Algae.
148
In water what is true color?
TrueColor is due to substances in true solution a.k.a. dissolved substances.
149
In water what is apparent color?
Apparent color includes TrueColor and substances in suspension rather than dissolved.
150
How can industrial wastes and turbidity affect water?
These can change the color of water.
151
What is turbidity?
Turbidity is muddy or the unclear condition of water caused by particles of sand, Clay or organic matter being held in suspension.
152
What two things remain suspended in water for the longest period of time because of their particle size and specific gravity's?
Clay and silt.
153
How would you reduce water contamination, extend the time between backwashing the filters, decreased chlorine demand, improve disinfection, and enhance user acceptability of the finished water?
By removing turbidity.
154
Why would you use coagulation and sedimentation in water?
To remove turbidity.
155
Where would you determine dosages of coagulant chemicals?
At each water point.
156
After coagulation and settling, the water should not have more than how many percent of the original turbidity?
20%.
157
What type of test will help check the optimum chemical dosage required to meet a certain standard of coagulation?
Daily jar test.
158
How would you determine the type of chemicals needed for coagulating raw water?
By using the results from jar tests, plant tests, or the optimum pH range for common coagulant table.
159
What does pH in relation to water mean?
The term pH is used to describe the acid or base properties of water solutions.
160
What does a pH scale range from?
0 to 14
161
What is a neutral pH value?
7.
162
What is an acidic pH level?
Less than 7.
163
What is an alkaline pH value?
Above 7.
164
What would a pH value of less than seven in the wastewater plant influence indicate about the waste water?
It may indicate septic conditions of the wastewater.
165
What does a pH value of less than 5 and more than 10 indicate in waste water?
It may indicate industrial waste in the waste water which are not compatible with biological wastewater operations.
166
What can damage biological treatment units?
Industrial waste with extreme pH values.
167
What pH range would you use aluminum sulfate as a coagulant?
5.0 to 7.0
168
What pH range would you use Ferrous sulfate as a coagulant?
9.5 and above.
169
What pH range would you use chlorinated copper us as a coagulant?
4.0 to 6.5 and above 9.5
170
What pH range would use use ferric chloride as a coagulant?
4.0 to 6.5 and above 9.5
171
What pH range would you use ferric sulfate as a coagulant?
4.0 to 10.0
172
What would you do when determining proper coagulant dosages when treating water?
You would do a jar test.
173
How would you determine which chemical to use as a coagulant when treating water?
By doing more than one jar test.
174
When determining which coagulant to use by doing a jar test how many grams of coagulant would you use with 1 L of distilled water?
You would use 10 g of coagulant to 1 L of distilled water.
175
How many liters and how many samples would you divide raw water into?
6, 1 liter samples.
176
If you divide raw water into 6, 1 liter samples how much coagulant would you add into each of those samples?
5, 10, 20, 30, 40, 50mg
177
How long would you let the coagulant in raw water samples settle?
30 minutes after stirring.
178
What instrument would you use to determine the turbidity of water?
Turbidometer.
179
The smallest amount of coagulant that produces the lowest turbidity represents what?
The optimum dosage.
180
How would you get the correct chemical feed in pounds per million gallons?
Multiply the coagulant dosage in mg/1 by 8.33.
181
Tastes and odors of water are caused by what?
Algae
Decomposing organic material
Dissolve gases
Industrial wastes
182
How do you prevent or remove unacceptable tastes and odors from treated water?
Using free available chlorine
Aeration
Activated carbon
183
What is an effective agent to use to get rid of organic color in water?
Activated carbon.
184
What would you add to activated carbon when it is being used in continuous flow equipment?
Add to Limestone feeder with limestone slurry.
185
Activated carbon can be added with chemicals in a coagulation tank with what type of equipment?
Batch type equipment.
186
Activated carbon affects pH values and chemical characteristics of water, true or false?
False.
187
What is the minimum and maximum amount of carbon to be used per 1000 gallons of water?
1 ounce to 1 pound.
188
What type of treatment consists of adding oxygen by exposing water to air?
Aeration treatment.
