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 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

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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 )

6

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

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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

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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

ENVS402 EIA by Dr. Subodh Sharma

9/16/2011