5th 6th month final Flashcards
1
Q
Acid rain is formed by the evaporation of acid waters from mine drainage.
A
false
2
Q
the link between water demands and pumping costs is a driving force behind water conservation programs
A
true
3
Q
both plant life and animal life depend on water for survival
A
true
4
Q
sources of contamination include
A
intrusion of seawater
mineral residue from irrigation
acid rain
tce
5
Q
sources of groundwater contamination include
A
human activities
intrusion of seawater
seepage from septic tanks and leaching systems
agricultural drainage systems
sanitary landfills and dumps
surface runoff into poorly constructed wells
6
Q
tress basic types of water rights
A
riparian
appropriative
prescriptive
7
Q
surface water supplies may be divided into which of the following classes
A
lakes
reservoirs
rivers
8
Q
diseases that may spread through a water supply
A
dysentery
giardiasis
typhoid fever
9
Q
clear water is safe drinking water
A
false
10
Q
running water purifies itself
A
false
11
Q
some cities draw drinking water from a stream or river into which the treated wastewater from upstream cites has been discharged
A
true
12
Q
lake and reservoirs are susceptible to algal blooms when
A
temperature is right
enough nutrients are in water
13
Q
what are the general water quality characteristics of surface water supplies
A
suspended solids
turbidity
14
Q
before selecting a location and constructing a water supply intake in a river or stream, careful consideration must be given to
A
the stream bottom
degree of stream scour
the settling out of silt
15
Q
the process by which water vapor is released to the atmosphere by living plants
A
transpiration
16
Q
typical use of reclaimed water
A
food crop and nonfood crop irrigation
landscape irrigation industrial reuse
landscape impoundments
17
Q
laboratories are able to adequately detect all potentially toxic chemicals
A
false
18
Q
when conducting a sanitary survey, which of the following items would pertain to a ground water supply
A
distance of local sources of pollution
nature of soil
slope of water table ground surface
well construction
19
Q
when conducting a sanitary survey, which of the following items would pertain to a water supply in a lake
A
safe yield algae growth potential detention time protective measures according to the use of the watershed drift of pollution wind direction
20
Q
items requiring protective measures in watershed that serve as the source of a water supply include control of
A
disposal of brines fishing swimming ice cutting sanitary landfills
21
Q
precipitation is high in bacteria count
A
false
22
Q
agents which alter the quality of water as it moves over or below the surface of the earth may be classified under four headings
A
physical
chemical
biological
radiological
23
Q
the amber color in water could indicate the presence of
A
acid waters from mine drainage
humic substances
24
Q
turbidity can be characterized as
A
suspended material
finely divided organic material
plankton
25
color in water is mainly objectionable from the standpiont of health
false
26
most individuals find that water having a temp between _____ is most pleasing
50--60
27
specific disease producing organisms present in water are not easily isolated and identified
true
28
a public water system is
has at least 15 service connections which are used at least 60 days out of the year
serve an average of at least 25 people at least 60 days out of the year
29
in the operation of water treatment plants, three basic objectives are
production of safe drinking water
production of aesthetically pleasing drinking water
production or drinking water at a reasonable cost
30
when referring to a clock
under generation = ____
over generation = _____
slow time error
fast time error
31
all load can be divided into two types
non motor load ( non spinning load)
motor load ( spinning load)
32
according to the load/frequency relationship, a 1% change in frequency will lead to what approx. magnitude of load change in a typical 10000mw system
9800mw (2% change in total)
33
if the voltage falls enough it will cause the motor to speed up
false
34
electric generators use ___ to control shaft speed
governor control systems
35
list three types of utility generators that use governor control systems
hydro turbines
combustion turbines
steam turbines
36
_____ is common on older generating unit
centrifugal ballhead governors
37
a governor with 0% speed droop is called ____
isochronous control
38
steam turbine generators typically have better response than hydro-electric generatos
false
39
the north american power system is divided into areas called interconnections
true
40
what is not a control mode for agc operation
isochronous control
41
a control areas frequency bias setting is equal to
the control areas frequency response characteristics
the natural response of the control area
the agc system bias value
42
a control area has a bias of -150mw . frequency falls to .5hz due to an external disturbance. how many mw will the control area provide towards the disturbance
+150mw
43
if the system frequency ran at 60.02hz for 2hrs, how much positive time error would occur
2.4 seconds. 1.2 seconds per hour
44
what element of power system is typically most susceptibe to damage from prolonged operation at frequencies above or below 60hz
the long blades of low pressure steam turbines
45
in which stage of a generators response to a system disturbance is the powerflow supported primarily by the generators excitation system
the electromagnetic energy state
46
complex power is a vectorial difference
false
47
a transmission line is rated at 1000mva. the power flow is 0mw and 1001mvar. is the line overloaded
yes
mva = √(〖0MW)〗^2+(〖1001MVAR)〗^2=1001MVA
48
A distribution line is rated at 50MVA. The line’s power flow is 50MW and -50MVAR. The distribution line is overloaded.
true
49
The Greek letter Theta with no subscript Θ is used to represent:
phase angle
50
The larger the power angle (up to approx. 90°) the larger the active power flow between two points.
true
51
. A synchroscope is used to compare what three things:
1. Frequency
2. Phase
3. Magnitude
52
Three factors affecting active power flow:
1. Power angle
2. Voltage magnitude
3. Path impedance
53
A phase shifting transformer’s primary function:
b) Adjust system active power flows.
54
. MVAR flow is influenced more by system and torque angles than by reactive power
false
55
At what line power angle does MW transfer across a transmission path equal ½ of the path’s PMAX ?
c) Power angle of 30 degrees.
56
. Max continuous active power transfer between two buses:
d) Power angle of 90 degrees.
57
Maximum MVAR flow occurs at an angle:
e) Power angle of 180 degrees
58
Thermal limits are the direct result of:
a) The thermal capability of power system equipment
59
Angle stability limits are the result of:
b) High power and torque angles
60
The TTC (Total Transfer Capability) has been determined to be 1000MW from east to west. 500MW is sold of the TTC. What is the ATC (Available Transfer Capability)?
c) 500MW
61
100MW total flow and path A-B has 10% distribution factor (figure 3-27). How many MW is the distribution factor:
d) 20MW
62
1. Methods of managing lakes and reservoirs used for domestic water supplies vary widely depending on:
a) Local situations
63
2. The amount and type of public use allowed on reservoirs has been standardized by laws and regulations:
False
64
3. Many of the conditions which adversely affect water quality in domestic water supply reservoirs result from overuse of the environment
True
65
The impact of our activities within a given reservoir’s drainage area affects the water quality by:
a) Agricultural run off
b) Grazing of livestock
c) Drainage from mining areas
d) Run off from urban areas
e) Logging operations
66
a) Nutrients act as a ___ in a lake.
a) Fertilizer
67
b) Reservoirs and lakes that are rich in nutrients and thus very productive in terms of aquatic animal and plant life:
b) Eutrophic
68
Common water quality problems in domestic water supply reservoirs:
a) Taste and odor problems
b) Shortened filter runs increased PH
c) Dissolved oxygen depletion
d) Organic loading
69
Objectionable tastes and odors in the domestic water supply are often related to algal blooms.
True
70
Chlorination can either reduce or increase the taste and odor in the water supply.
True
71
. Many conventional water treatment plants are capable of reducing or eliminating tastes and odors when properly operated
True
72
Overturn in water supply reservoirs can cause:
a) Algal blooms
b) Plankton
c) Hydrogen sulfide
73
Algae can die of oxygen starvation
True
74
Fish kills can result from algae clogging the gills of fish.
True
75
The organic loading resulting from algal blooms is often associated with high trihalomethane levels following free residual chlorination
True
76
In a monolithic lake, the water temperature during winter months is uniform from top to bottom.
True
77
Mixing occurs between the epilimnion and hypolimnion zones in thermally stratified lakes.
False
78
Anaerobic conditions in the hypolimnion of a reservoir can cause:
a) Fish kills
b) Iron and manganese problems
c) Rotten egg odors
79
. Purpose of reservoir management programs:
a) Improvement and maintenance of fishery, recreational and property values
b) Reduction of water treatment costs
c) Control frequency and intensity of algal blooms
d) Control dissolved oxygen depletion
80
Proper lake management can increase recreational values of a reservoir by:
a) Controlling man’s activity on the water shed
b) Reduce large mats of algae
c) Reduce scums of algae
d) Remove vegetation before flooding
81
trees and brushes should be removed from areas to be flooded by reservoirs to reduce the:
a) Nutrient loading
| b) Organic loading
82
once vegetation is accomplished regrowth must be controlled by mechanical means until the reservoir is filled.
True
83
. Factors affecting watershed management programs:
a) Size
b) Topography
c) Vegetative conditions
d) Water quality problems
84
In most cases, the best tool for managing watershed is probably the regulatory process.
True
85
Watershed practices that can affect water quality in a water quality supply reservoir:
a) Septic tank leeching systems
b) Fertilization practices
c) Oil and gas explorations
d) Livestock grazing
86
Destratification always increases the number of algal bloom in reservoirs.
False
87
important water quality indicators that should be considered in a lake destratification program include:
a) Dissolved oxygen
| b) Temperature
88
With complete destratification, temperatures in a reservoir will be nearly uniform from top to bottom.
True
89
Through proper design and operation, destratification systems can be used to adjust temperatures as well as dissolved oxygen levels
True
90
The small system operator must be able to manage a water supply as well as a large system operator
True
91
Water quality lab analysis which may be best performed by commercial labs include:
a) Trihalomethanes
b) Radio activity
c) Pesticides
d) Temperature
92
Records are very valuable only when they are completed and filed by lab personnel.
False
93
Intake facilities should be constructed in such a manner that they prevent:
a) Algal scums
| b) Fish
94
The single level intake is usually located in the deepest portion of the stream or reservoir so that water service can still be provided even when the body of water is down to its minimum operating level
True
95
Anaerobic water entering the inlet may contain high concentrations of:
a) Iron
b) Manganese
c) Hydrogen sulfide
96
Various types of screens include:
a) Vee wire
b) Woven wire
c) Slotted plates
97
Techniques for cleaning screens:
a) Bristle brushes
b) High pressure water spray
c) Reverse flow
98
What are the two types of power produced by system generators
active power and reactive power
99
Given a purely inductive load, what can be said about the MVA this load draws from the power system
draws only MVAR
100
Name 4 common causes of low voltage
heavy power transfers
transmission line outages
reactive equipment outages
failure to get ahead of the voltage
101
a 345kv transmission line operates at various voltage levels throughoutthe day. at what voltage level will the transmission line produce more reactive power
360kv
102
A transmission lines ____ is the MW loading at which the Mvar from the line's natural capacitance is equal to the mvar the line needs to suppor its voltage
surge impedance loading
103
Generators are the primary means of controlling power system voltages
true
104
what is the mavr production of a 50mvar shunt capacitor that is energized at 90% of its nominal voltage
mvar output = 50mvar * (.90 rated votage)squared
40.5 mvar
105
Excessively high voltages on the power system are less dangerous then low voltages
false
106
three general time frames for overvoltage
long term overvoltage
short term overvoltage
transient over voltage
107
The sudden loss of a major load can lead to short term excessive generator production of active and reactive power
true
108
a 5% change in voltage will lead to what change in total load magnitude
3%
109
Transformers are very susceptible to damage from sustained _____ hig voltages
high
110
a transformer can be overexcited if exposed to
high voltages
| low frequency
111
A transmission line has 50ohms of inductive reactance. 25ohms of capacitive reactance is inserted. what is the line's series compensation
[((50Ω-25Ω))/50Ω ]×100=50%
112
what is the approximate mvar/mile production for a 345kv overhead line
3/4mvar per mile
113
what is the approximate mvar/mile production for a 500kv overhead line
2mvar per mile
114
a generator with spare mvar is always a source of dynamic reactive reserve
false
115
how are dams classified
according to their use, hydraulic design or the materials in which they are constructed
116
what is the purpose of a detention dam
to retard flood run off and minimize the effect of sudden floods
117
what is the membrane of a rock filled dame made of
upstream facing of impervious soil, a concrete slab, asphaltic concrete paving, steel plates, other impervious elements or interior thin core of impervious soil
118
why is a timber dam not economical for construction
the amount of labor involved along with the short life of the structure makes it uneconomical for modern construction
119
The investigation for a potential dam site primarily consists of three stages or areas of study, what are they
appraisal, feasibility and design investigations.
120
what is the primary criteria for rip-rap
quality and size
121
why is it important to have an effective reservoir geologic map
for planning and conducting investigations
122
in construction of foundation and earth work for dams, why are the physical properties of soil important
of primary importance are the physical properties of soil such as unity weight, permeability, shear strength, compressibility, and the soil's interaction with water.
123
in field classification, if the soil is gravel it can be identified as clean or dirty, what does dirty mean
containing an appreciable amount of fines
124
what are the mechanisms that develop soil deposits on the surface of soils
water, ice and wind action for transported soils; mechanical-chemical action of weathering for residual soils.
125
what are the non accessible exploration methods for subsurface materials
auger, rotary and core drilling
126
why is the earthfill dam the most common type of dam
its construction involves using material in their natural state with little processing
127
what is the purpose of grouting a dam foundation
grouting acts as a binder and fills in the voids in the foundation
128
what is the purpose of toe drains
to collect seepage discharging from the embankment and foundation of a dam and discharge it at an elevation below the dam
129
what are the methods of treating silt and clay foundations based on
soil type, location of water table, and the density of the soil
130
in reference to dams, what does the term freeboard mean
the vertical distance between the crest of the embankment and the reservoir water surface
131
what type of rock should be used for rip rap
metamorphic, igneous, limestone and sandstone.
132
what are the three conditions that must occur before a rock fill dam can prove to be exonomical
large quantities of rock are readily available, earthfill materials are difficult to obtain and short construction seasons prevail
133
does uplift pressures and erosion caused by seepage through rockfill dam generally cause problems
no
134
name three materials that are used as impervious material in rockfill dam
earth materials, concrete , steel, asphaltic concrete and wood
135
name two advantages of using an internal membrane in a rockfill dam
less total area exposed to water and protection from the effects of weathering and external damage
136
what type of foundation requirements are the most desirable for a rockfill dam
bedrock foundations that are hard and erosion resistant
137
how are outlet works classified
purpose, physical and structural arrangement and their hydraulic operation
138
why is the outlet works position in relation to the reservoir storage level so important
in order to obtain required discharge capacity, the outlet must be placed sufficiently below the minimum reservoir operating level to provide the head required for outlet works flow
139
if a trash rack is accessible for cleaning, what can the ft/sec be through the trashrack
5ft/sec
140
what is the formula to calculate flow
q=cdl square root 2gh
141
what is the most accepted shape for earthen canals
trapezoidal in shape
142
what range of permissible velocities is considered for sizing of a canal water section
1.5 feet per second for smaller laterals and 3fps for the larger canals
143
why are steel flumes seldom used today
costly maintenance
144
where are concrete bench flumes most commonly used
mostly on difficult steep sidehill terrain
145
what shape of flumes gives the maximum velocity for a given area
one which has a bottom width of twice the water depth
146
what are the most common types of construction for siphon services
buried precast concrete pipe, monolithic concrete pipe, and overhead or elevated steel pipe on concrete piers
147
why is concrete pipe predominately used for canal siphons
hydrostatic heads encountered are generally less than 150ft bridges supporting canal sections across drainage channels, over highways and railroads are generally more expensive. sizes from 12 to 96 inches are available for most localities
148
when is monolithic construction generally considered
for siphons larger than 96 inches in diameter
149
what essential design features, in additions to the pipe itself must be considered for inverted siphons
inlet and outlet transitions, blow off structures
150
what purpose do the inlet and outlet transition serve
allow appreciable change in velocities to occur at inlet and outlet of the siphon. minimizes head losses and erosion damage
151
name three types of blow off structures
pump type, gravity type, and pressure turnout type
152
when feasible where should blow offs be located
low points of siphon where water is drained inot natural drainage channels.
153
what is the purpose of a chute (drop)
to convey water over relatively steep slopes in order to lower the water surface in canals
154
what purpose do the controlled notch of stoplogs serve in the inlet transitions of drops and chutes
to prevent drawdown velocities at the entrance of the chute that would result in erosion of the canal banks
155
what is the preferred shape of a monolithic reinforced concrete chute
rectangular
156
besides stoplogs, what device are used to control water levels at the inlet transition of monolithic reinforced concrete drops and chutes
a series of notch controls or a check structure
157
what purpose do cross drain structures serve
to protect canals and laterals from damage from storm waters
158
when are culverts used for cross drainage
where the canal is carried across the drainage channel upon an embankment
159
for large canals, what storm frequency is used to develop culvert size
100 year storm frequency
160
what purpose do pipe collars serve in culvert construction
to prevent seepage from the canal from piping along the top of the culvert and causing the canal bank to fail. also to prevent burrowing animals from making tunnels along the culvert
161
what is the purpose of an overchute
it is an elevated flume for carrying drainage water over canals
162
what basic functions must a turnout provide
flow control and flow measurement
163
what devices are generally employed for flow control at turnouts
vertical lift cast iron gates are usually used for the control gates for pipe turnouts and radial steel gates are used for larger turnouts
164
what two measuring structures are predominately used in small turnouts
the parshall flume and weir and the ciplletti weir
165
what purpose do checks serve
to control the water level in the canal and to maintain proper levels to make turnout deliveries
166
describe two general types of checks used in small canals
flashboards for regulation and combination of flashboard and gates for regulation
167
do radial gates checks of the California aqueduct employ overflow wirs? why?
no. controlled volume concept of aqueduct operations requires total regulation of water flows through known openings that cannot be achieved utilizing overflow weirs
