8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 2/266
A handbook prepared under contract for theCommission of the European Communities,Directorate-General for Energy byEuropean Small Hydropower Association (ESHA)
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 5/266
D I R ED I R ED I R ED I R ED I R E CCCCC T O R AT O R AT O R AT O R AT O R A T ET ET ET ET E G E N E R A LG E N E R A LG E N E R A LG E N E R A LG E N E R A L F O RF O RF O RF O RF O R E N E R GE N E R GE N E R GE N E R GE N E R G YYYYY ( D G X V I I )( D G X V I I )( D G X V I I )( D G X V I I )( D G X V I I )
E U RE U RE U RE U RE U R O P EO P EO P EO P EO P E A NA NA NA NA N C O MC O MC O MC O MC O M MMMMM I S II S II S II S II S I OOOOO NNNNN
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 6/266
AUTHOR
Celso Penche
Dr Ingeniero de Minas (U.Politécnica de Madrid)
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 15/266
1.0 A free fuel resource potentially everlasting.
1. Introduction
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 16/266
1.1 Definition of small hydropower
1.2 Site configurations
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 17/266
1.2.1 Run-of-river schemes
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 19/266
1.2.2 Schemes with the powerhouse at the base of a dam
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 20/266
1.2.3 Schemes integrated with an irrigation canal
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 21/266
1.2.4 Schemes integrated in a water abstraction system
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 22/266
1.3 Planning a small hydropower scheme
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 25/266
2.0 Introduction
2.1 Water flow in pipes
g
g
=
ν
n
2. Fundamentals of Hydraulic Engineering
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 27/266
2.1.1 Los of head due to friction
=
F H G
I K J
= = µ
ρ
= × × =
µ ρ
µ ρ
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 28/266
=F
H G
I
K J
=
F H G
I K J
= − +F
H GG
I
K J J
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 30/266
p
u u
= × × × =
α =
α α = − +F H G
I K J
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 32/266
m
µ =
µ ν
=
m
= − +F
H GI
K J
µ
µ
m
m
µ = × ×
× ×= ×
−
= − × × ×
+× ×
F
H G
I
K J = ×
−
= =
×= =
ν
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 36/266
=
F H G
I K J
2.1.2 Loss of head due to turbulence
2.1.2.1 Trash rack (or screen) losses
= F H G I K J
F H G
I K J
Φ
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 37/266
b b
β β =
2.1.2.2 Loss of head by sudden contraction or expansion
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 38/266
=
F H G
I K J
=
−= −
F H G
I K J
= −F H G
I K J
= −F H G
I K J
b g
a
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 39/266
=
−
2.1.2.3 Loss of head in bends
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 40/266
2.1.2.4 Loss of head through valves
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 41/266
2.1.3 Transient flow
=
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 43/266
= ×
+
−
= ∆
D
∆
= + +F
H G
I
K J
=
F H G
I K J
ρ
r
D
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 44/266
2.2 Water flow in open channels
2.2.1 Clasification of open channel flows
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 45/266
2.3.2 Uniform flow in open channels
=
=
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 46/266
=
=
2.2.3 Principles of energy in open channel flows
g
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 47/266
γ γ γ = = − = +
g
= + α
a a a
= +
= +
a
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 50/266
Φ Φ−
+ + φ
−b g
+
+
+ +
b g
−
F H G
I K J
Φ
Φ
+
+
b g
Φ Φ
Φ
−F
H
GGG
I
K
J J J
+
+
b g
θ θ
θ
−
b g
Ψ
F H G
I K J
Ψ
F H G
I K J −
F
H G
I
K J Ψ
YYYYY aaaaa
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 51/266
2.3 Computer programs
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 55/266
3.0 Introduction
g
g
3 The water resource and its potential
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 57/266
3.2 Evaluating streamflows by discharge measurements
3.2.1 Velocity-area method
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 59/266
=
−
+ −
3.2.1.1 Measuring the cross-sectional area
= × + + +
3.2.1.2 Measuring the velocity
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 63/266
D
Q V
T
V
v
c
c= × ×
* *
'
∆
∆
D
∆
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 64/266
3.2.3 Weir method
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 65/266
3.2.4 Slope-area method
=
D i s c h a r g e m / s
3
Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 66/266
3.3 Streamflow characteristics
3.3.1 Hydrograph
3.3.2 Flow Duration Curves (FDC)
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 68/266
3.3.3 Standardised FDC curves
3.3.4 Evaluating streamflows at ungauged sites
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 70/266
3.3.5 European Atlas of Small Scale Hydropower Resources
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 72/266
3.3.6 FDC’s for particular months or other periods
3.3.7 Water pressure or ‘head’
3.3.7.1 Measurement of gross head
3.3.7.2 Estimation of net head
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 74/266
3.4 Residual, reserved or compensation flow
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 75/266
3.5 Estimation of plant capacity and energy output
h h h h g
h
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 77/266
h
h
h
h
D
h h h h
g
g
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 78/266
3.5.1 How the head varies with the flow and its influence on the turbinecapacity
=
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 79/266
3.5.2 Another methodology to compute power and annual energy output
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 80/266
h
D
3.5.3 Peaking operation
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 81/266
Qop
24 QR Qres tpQP
top
Qmin
= − −
>b g
3.6 Firm energy
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 85/266
4.0 Introduction.
4.1 Cartography
4. Site evaluation methodologies
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 86/266
4.2 Geotechnical studies
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 87/266
4.2.1 Methodologies to be used
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 88/266
4.2.2 Methodologies. The study of a practical case.
4.2.2.1 The weir
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 90/266
4.2.2.2 The open channel
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 92/266
4.2.2.3 The channel in tunnel.
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 94/266
4.2.2.4 The powerhouse
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 96/266
4.3 Learning from failures
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 103/266
5.1 Structures for storage and water intake
5.1.1 Dams
5.1.2 Weirs
5. Hydraulic structures
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 105/266
5.1.2.1 Devices to raise the water level.
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 111/266
5.1.4 Energy dissipators
5.1.5 Low level outlets
5.1.6 River diversion during construction
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 112/266
5.2 Waterways5.2.1 Intake structures
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 113/266
5.2.1.1 Water intake types
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 115/266
5.2.1.2 Intake location
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 116/266
5.2.2 Power intake
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 119/266
5.2.3 Mechanical equipment5.2.3.1 Debris management in intakes
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 121/266
=
+F H G
I K J
α
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 123/266
α α =
F H G
I K J
a a
a
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 124/266
5.2.3.2 Sediment management in intakes
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 126/266
5.2.3.3 Gates and valves
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 129/266
5.2.4 Open channels
5.2.4.1 Design and dimensioning
= =
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 131/266
S QnP
A
Qn
AR=
F H G
I K J
= F H G
I K J
2 3
5 3
2
2 3
2 /
/ /
=
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 134/266
A 1.5 0.5 1 1 2m ; P 1 .5 2 1 0.5 3.736m2 2= + × × = = + × + =b g
Q 1
0.015
25/ 3
3.7362/ 3 0.001 2.78 m3 /s; V
2.78
21.39m/s= × × = = =
= ××
F H G I K J =
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 135/266
AR nQ
S
2 3 0 012 11
0 0014174 / .
..= =
×=
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 137/266
5.2.4.2 Circumventing obstacles
5.2.5 Penstocks
5.2.5.1 Arrangement and material selection for penstocks.
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 141/266
5.2.5.2 Hydraulic design and structural requirements
gh
g
h
=
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 142/266
=F
H GI
K J
= F
H
G I
K
J
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 143/266
= ×
+× × =
= ×F H G
I K J
××
× =
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 144/266
= × ×
× =
=
σ
s
= +
σ
s
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 145/266
= ×
F H G
I K J
=
Pc ≤ 0 49. kgN / mm2 =
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 146/266
= ∆
D
= ×
+ × ×
× ×
=
= ×
+ × ×
× ×
=
= ×
=
= ×
=
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 147/266
=
F H G
I K J
D
= ×
+ × ×
× ×
=
= ×
×=
π
= ×
× ×
F H G
I K J
=
∆
= ± +
F
H G
I
K J = + −
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 148/266
= ×
×+ =
Pc = F H G I K J =882500 5
10000 11
3
. kN / mm2
d = =7 47 3
0 1122 46.
.. cm
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 151/266
5.2.5.3 Saddles, supporting blocks and expansion joints
F W W L cosF1 p w= +c h
Wp W
w
L F
L 182.61D 0.0147
4D43
P= ×
+ −b g
5.2.6 Tailraces
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 153/266
6.0 Powerhouse
6 Electromechanical equipment
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 155/266
6.1 Hydraulic turbines
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 157/266
6.1.1 Classification criteria
6.1.1.1 On the basis of the flow regime in the turbine
6.1.1.1.1 Impulse turbines
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 159/266
6.1.1.1.2 Reaction turbines
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 164/266
6.1.1.2 On the basis of the specific speed
= × =
F H
I K
= = F
H
I
K
= =
= = × = F H G
I K J
×
= =F H
I K
F H
I K
F H
I K
F H
I K
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 165/266
=
=
F H G
I K J
F H G
I K J
=
F H G
I K J
=
=
Ω ρ
b g
W r
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 167/266
= = =
= ×
=
π
π
d Q
v
Q
H
j
j
= =4
3 37π .
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 168/266
d P
H j =
2807 3 2
. /
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 170/266
=
6.1.2 Turbine selection criteria
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 177/266
6.1.3 Turbine efficiency
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 179/266
6.1.4 Turbine performance characteristics
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 180/266
6.1.5 Turbine performance under new site conditions
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 182/266
= = F H G
I K J
= F
H G I
K J
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 183/266
= = F H G
I K J
F H G
I K J
=
= F
H G I
K J
6.2 Speed increasers
6.2.1 Speed increaser types
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 184/266
6.2.2 Speed increaser design
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 185/266
6.2.3 Speed increaser maintenance
6.3 Generators
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 187/266
6.3.1 Generator configurations
6.3.2 Exciters
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 188/266
6.3.3 Voltage regulation and synchronisation
6.3.3.1 Asynchronous generators
6.3.3.2 Synchronous generators
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 189/266
6.4 Turbine control
6.4.1 Speed Governors
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 192/266
= =
Ω
=∑
6.5 Switchgear equipment
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 194/266
6.6 Automatic control
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 195/266
6.7 Ancillary electrical equipment
6.7.1 Plant service transformer
6.7.2 DC control power supply
6.7.3 Headwater and tailwater recorders
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 197/266
6.7.4 Outdoor substation
6.8 Examples
h = 1.5
= =
= = × × =
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 198/266
= =
×=
π π
= × × × ×
=
π
= × × × ×
=
π
σ = × × =−
= − − × = −
s
hhhhh
= = =
= =
× ×=
γη
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 199/266
= = =
= = =
= = =
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 201/266
7.0 Introduction
7. Environmental impact and its mitigation
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 202/266
7.1 Burdens and impacts identification
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 203/266
7.2 Impacts in the construction phase
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 204/266
7.2.1 Reservoirs
7.2.2 Water intakes, open canals, penstocks, tailraces, etc.
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 205/266
7.3 Impacts arising from the operation of the scheme
7.3.1 Sonic impacts
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 206/266
7.3.2 Landscape impact
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 214/266
7.3.3 Biological impacts
7.3.3.1 In the reservoir
7.3.3.2 In the streambed
7.3.3.2.1 Reserved flow
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 216/266
7.3.3.2.2 Fish passes (upstream fish)
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 224/266
7.3.3.2.3 Fishpasses (downstream fish)
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 232/266
7.3.3.3 In the terrain
7.3.4 Archaeological and cultural objects
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 233/266
7.4 Impacts from transmission lines
7.4.1 Visual impact
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 234/266
7.4.2 Health impact
7.4.3 Birds collisions
7.5 Conclusions
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 237/266
8.0 Introduction
8.1 Basic considerations
8 Economic Analysis
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 240/266
8.2 Financial mathematics
=
+
F
H GG
I
K J J b g
×
+=
b g
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 242/266
a v v v vn
n= + + + +
1 2 3 ...
= −
= + −
+=
− + −
b gb g
b g
an
a a3
3
3
1 1 0 08
0 082 577 200 515 42=
− += × =
−.
.. ; .
b gthen ECU
8.3 Methods of economic evaluation
8.3.1 Static methods (which do not take the opportunity cost intoconsideration)
8.3.1.1 Pay-back method
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 243/266
8.3.1.2 Return on investment method
8.3.2 Dynamic methods
8.3.2.1 Net Present Value( NPV) method
= − + +
++
=
=
∑
b gb g
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 244/266
8.3.2.2 Benefit-Cost ratio
= +
+ +
+
∑
∑
b gb g
b g
8.3.2.3 Internal Rate of Return method
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 246/266
NPV =i= 4
i=36 R O M
r
I
r
i i i
i
i
i
i
i− +
+−
+=
=
∑∑ b g
b g b g1 10
3
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 248/266
8.4 Financial analysis of some European schemes
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 253/266
9.0 Introduction
9.1 Economic issues
9. Administrative procedures
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 256/266
9.3 How to support renewable energy under deregulation*
9.5.1 Set asides
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 258/266
9.2.2 Emission Taxes, Caps and Credits
9.2.3 Green pricing.
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 259/266
9.2.4 Imposed tariffs
9.2.5. Miscellaneous
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 260/266
9.3 Technical aspects
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 261/266
9.4 Procedural issues
8/13/2019 Layman Guidebook
http://slidepdf.com/reader/full/layman-guidebook 263/266
9.5 Environmental constraints