ENVS402 – Environmental Impact Assessment
Chapter 6: Executing the EIA Process 1. 2 2. 3. 4 4. 5. 1
Alternative Analysis T Types off Impacts I Metho...
Chapter 6: Executing the EIA Process 1. 2 2. 3. 4 4. 5. 1
Alternative Analysis T Types off Impacts I Methods of identifying impacts Impact prediction techniques Impact evaluation 9/16/2011 ENVS402 EIA by Dr. Subodh Sharma
Alternative Analysis Analysis carried out on the basis of various biophysical Analysis carried out on the basis of various biophysical and socioeconomic parameters including: 1. technical feasibility, 2. economic viability and 3. environmental acceptability of the project. This analysis provides information about the advantages and disadvantages of each alternative considered. It can be done during the scoping process or report It can be done during the scoping process or report preparation.
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ENVS402 EIA by Dr. Subodh Sharma
9/16/2011
Types of Alternatives Two types of alternatives are taken: 1. Do‐nothing or no action or status quo alternative • No change in the socioeconomic conditions or the services to the society, and in some area environmental degradation will y, g continue. 2. Implementation of the project (with multiple alternatives) 2. Implementation of the project (with multiple alternatives) • Favors implementation of the project by considering alternatives in terms of site selection, design and operational methods, project scale and timing of the project. methods, project scale and timing of the project. • Example of the alternatives to be considered can be alternative access roads, reducing vehicular emission or traffic, reduction in surface run off etc surface run off etc 3
ENVS402 EIA by Dr. Subodh Sharma
9/16/2011
Alternative Analysis Considering Alternatives
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ENVS402 EIA by Dr. Subodh Sharma
9/16/2011
Alternative Analysis – legal Provisions Section 4 of EPR 1997 requires the proponent to consider the following aspects as alternatives in an EIA study the following aspects as alternatives in an EIA study‐ • Design, Project site, • Technology, operational procedure, time schedule and raw materials • Environmental management systems • Acceptance of the risks p • Other matters • Magnitude, extent and duration of the impacts should be considered for comparison of alternatives considered for comparison of alternatives • These impacts can be evaluated quantitatively, qualitatively or by using ranking, rating or scaling approach 5
ENVS402 EIA by Dr. Subodh Sharma
9/16/2011
Methods of Alternative Analysis 1. Unranked Paired Comparison Technique – Simple Technique Unranked Paired Comparison Technique Suppose there are four decisive factors in the plan such as; F1 = Relating to the degree of achieving overall objective; F2 = Relating to the economic efficiency; F3 = Relating g to the social concerns; F4 = Relating to the environmental concerns; and F5 = Dummy factor
Decision Factors
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Assignments of Weights
Sum
FIC
F1
1
1
1
1
4
0.4
F2
0
1
0
1
2
0.2
F3
0
0
0
1
1
0.1
F4
0
1
1
1
3
0.3
F5
0
0
0
0
0
0.00
Total
1
3
2
4
10
1.00
ENVS402 EIA by Dr. Subodh Sharma
9/16/2011
Methods of Alternative Analysis 1. Unranked Paired Comparison Technique – Complex Situation
F1 has three scenarios (A1 , A2 A2, A3); F2 has three scenarios F3 has three alternatives; F4 has three alternatives Decision F t Factors A1
A2
F1
Achieve greatest degree of f lf ll fulfillment off needs d andd objectives
Achieve least degree Achieve medium off needs d andd d degree off meeting objectives needs and objectives
F2
Medium economic efficiency
Low economic efficiency
High economic efficiency
F3
Undesirable social impacts expected
No social impacts expected
Beneficial social impacts expected
Decrease overallll D environmental quality by 10%
Decrease overallll D environmental quality by 10%9/16/2011
F4 7
Alternative Proposals
ENVS402 EIA
Decrease overallll D environmental quality by by Dr. Subodh Sharma 20%
A3
Methods of Alternative Analysis Scaling/Rating g g /Ranking g of Alternatives Relative to F1,, F2,, F3 and F4 Alternatives F1
Sum
ACC
Alternatives F2
3
0 50 0.50
A1
1 0
1
0.17
A2
0
1 2
0.33
A3
0 0 0
0.00
A4(dummy)
6
1.00
Grand Total
Sum
ACC
Alternatives F4
1
0.17 A1
0 0
2
0.33 A2
1
1 3
0.50 A3
Assignments of Desirability
A1
1 1
A2
0
A3
1 0 1
0
A4(dummy)
1 0
Grand Total Alternatives F3
Assignments of Desirability
A1
0 0
A2
1
A3
0 1 1
A4(d A4(dummy) ) Grand Total ENVS402 EIA 8
1 1
0 0 0 0
0 00 A4(dummy) 0.00 A4(d )
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1.00 Grand Total
by Dr. Subodh Sharma
Sum
ACC
2
0 33 0.33
1
0.17
1 3
0.50
0
0.00
6
1.00
Sum
ACC
1
0.17
2
0.33
1 3
0.50
0 0 0
0 00 0.00
6
1.00
Assignments of Desirability 1 0 1 1
1 0
0
Assignments of Desirability 1 0 1 1
1 0
9/16/2011
Alternative Analysis FIC (Factor (F t Important I t t Coefficient) C ffi i t) and d ACC (Alternative Choice Coefficient) values for Decision problems Decisi on Factor
FIC Value
ACC values of alternatives
A1
A2
A3
F1
0.40
0.50
0.17
0.33
F2
0.20
0.33
0.17
0.50
F3
0.10
0.17
0.33
0.50
F4
0.30
0.17
0.33
0.50
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ENVS402 EIA by Dr. Subodh Sharma
Decision Factor
ACC values of alternatives
A1
A2
A3
F1
0 200 0.200
0 068 0.068
0 132 0.132
F2
0.066
0.034
0.100
F3
0.017
0.033
0.050
F4
0.051
0.099
0.150
0.334
0.234
0.432 9/16/2011
2. Impact Ranking and Alternative Comparison
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• • •
Melamchi River intake capacity = 1o cumec Melamchi River intake capacity = 1o cumec Sedimentation tank 27 km long tunnel with a diameter of 2.5m
• • • •
Treatment plant at Sundarijal p j Balancing reservoir of 5 m cumec Diversion canal Access road of 60 km length
ENVS402 EIA by Dr. Subodh Sharma
9/16/2011
2. Impact Ranking and Alternative Comparison • • • • • • • •
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Roshi Khola – Located 20 km east of Kathmandu One 116 m high dam to provide storage of 58 million cumec Pressure tunnel 150 m in length Storage reservoir with capacity 3.3 million cumec within the valley Water treatment plant Access road of 5.5 km in length d f k l h 3,000 person workforce Resettlement of 310‐600 households
ENVS402 EIA by Dr. Subodh Sharma
9/16/2011
2. Impact Ranking and Alternative Comparison The Ranking method follows the National EIA Guidelines of Nepal An example p is from Melamchi Water Supply pp y Scheme Issues
Water Supply Scheme Melamchi
Mod Melamchi
Lower Roshi Khola
R d d ddownstream Reduced t water t supply l
5
5
10
Reduced downstream water quality
5
5
10
Increased downstream sediment transport
5
5
10
Increased downstream scouring
0
0
10
Deteriorating reservoir water quality
18
36
54
Increased c ease erosion e os o in general ge e a due ue to project
40
40
200
Total
73
91
114
Melamchi scheme was the most feasible with score 73 12