Environmental Impact Assessment (EIA)
EIA is a tool used for decision-making regarding
projects, developments and programmes
EIA is intended to identify
• environmental,
• social
• economic impacts of a proposed development
prior to decision-making
Environmental Impact Assessment (EIA)
It aims to predict environmental impacts at an early
stage in
• project planning and design
• find ways and means to reduce adverse impacts
• shape projects to suit the local environment
• and present the predictions and options to decision-
makers
Environmental Impact Assessment (EIA)
Environmental impacts may be ‘primary’ or ‘direct’
and ‘secondary’ or ‘indirect’.
Primary impacts are in fact the first round impacts
associated with projects, programmes and other
activities of man such as air pollution, water pollution,
noise, employment, generation, displacement of people
and businesses, etc
Secondary impacts are caused by project outputs. Most
of the socioeconomic environmental changes fall in the
category of ‘secondary’, i.e. induced effects or impacts
Environmental Impact Assessment (EIA)
Environmental impacts can also be classified as ‘short
term’ and ‘long term’ impacts.
Impacts which are felt in the shorter period of time
such as during construction period of a project and its
early phases of operation are ‘short-term’ in nature
Impacts which are felt in the longer period of time are
defined as ‘long-term’ impacts
Environmental Impact Assessment (EIA)
Method should be general enough
• to be applicable in a large number of environmental
impacts
• should at the same time look into an impact in required
details
Moreover, since all impacts cannot be classified as
negative, such as method should also take into
consideration, the positive side of human activity
BASICS OF EIA
Environment include
Biological systems (flora-fauna)
Air
Water
Soil and Geography/Topography
Society
Economy
Aesthetics
BASICS OF EIA
Applications of EIA
• Site selection for a proposed project
• Draft legislation
• Plant expansions
• Demolitions/controlled destructions
• Mining
• Milk processing
• National Parks/reserved forests
• Waste disposal
• Piggery/poultry farms
• Oil exploration/recovery
STEPS INVOLVED IN EIA
Step- 1 Screening
It is the step in which information is collected to
determine whether or not a proposal should be subject
to EIA and, if so, at what level of detail.
Schedule 1 - Environmental Assessments are required
in every case. Schedule 1 projects range from “an
integrated works for the initial melting of cast-iron and
steel”, to “a thermal power station or other combustion
installation with a heat output of 300 MW or more.”
STEPS INVOLVED IN EIA
Schedule 2 - Environmental Assessments are required
if the project is likely to give rise to significant
environmental effects by virtue of factors of their
nature, size or location
List of Schedule 2 projects is greater than that of
schedule 1. It covers projects from “a holiday village”
to “peat extraction” and “pig rearing” to “a shipyard”
STEPS INVOLVED IN EIA
Step- 2 Scoping
This is mainly done to identify the key issues and
concerns of the interested parties. Some of primary
motives of this step are to identify:
• Who is concerned?
• What are their concerns?
• Why are they concerned?
• What is the threshold of concern where change
becomes unacceptable?
STEPS INVOLVED IN EIA
Step-3 Examination of alternatives
• Establish the proper and benign option for choosing
the proposed alternatives
• Chose both the alternative sites and alternative
techniques
STEPS INVOLVED IN EIA
Step-4 Mitigating measures
• Reviews the action taken to prevent, avoid or minimize
the actual or potential adverse effects of a project
• Measure could include the
• abandoning or modifying of a proposal
• substitution of techniques using BATNEEC (Best
Available Technology Not Entailing Excessive
Costs)
• Include various pollution abatement techniques that
would be required to reduce emissions to the legal
limits
STEPS INVOLVED IN EIA
Uncertainty
• If the uncertainties are great, with the possibility of
grave consequences and no mitigating measures then
the development plan is rejected
• If there are uncertainties that might me reduced by
further studies then the applications deferred until
further studies are carried out.
STEPS INVOLVED IN EIA
Step-5 Preparation Of The EIS
EIS is a comprehensive document
• that reports the findings of the EIA
• Practically the final stage of the EIA process
• Is now often required by law before a new project
can proceed
STEPS INVOLVED IN EIA
Step-6 Review of EIS
Review of the EIS is required to determine whether the
report meets its terms of reference
provides a satisfactory assessment of the proposal(s)
contains the information required for decision-making
STEPS INVOLVED IN EIA
Step-6 Decision-Making
This step is done to approve or reject the proposal and
to establish the terms and conditions for its
implementation.
STEPS INVOLVED IN EIA
Step-6 Follow Up
Follow Up is to ensure that the terms and condition of
approval are met;
To monitor the impacts of development and the
effectiveness of mitigation measures
To strengthen future EIA applications and mitigation
measures; and, where required,
To undertake environmental audit and process
evaluation to optimize environmental management
MEASUREMENT OF ENVIRONMENTAL IMPACTS
For quantitative as well as qualitative assessment of
environmental impacts we need a stronger database.
The data will be concerned to various aspects of the
environment, such as
the physical environment: land, air, water, forests,
noise, animals, birds etc.,
economic environment: employment/unemployment,
economic activities, income levels, taxes, etc.
Issues in the implementation of EIA
1. Regulatory vs management tool
2. Legal framework
3. EIA evaluation period
4. Review process
5. Implementation mechanism
6. Baseline data
7. Regular monitoring
8. Institutional coordination
9. Public participation
10. Social acceptability
11. Local government
12. Training
Impact Assessment Methods
Adhoc methods
Simple methods based on unique combination of
experience, training and intuition
Impacts such as short term/long term;
reversible/irreversible are examined on guess basis
Sometimes this is the only required or possible
approach
In other instances, when more scientific methods are
available, it is not sufficient to rely on ad hoc methods
Impact Assessment Methods
Checklist method
Checklists are standard lists of the types of impacts
associated with a particular type of project
Checklists methods are primarily for
• organizing information or
• ensuring that no potential impact is overlooked
Formalized version of ad hoc approaches in that
specific areas of impact are listed and instructions are
supplied for impact identification and evaluation
Impact Assessment Methods
Checklist method
Reasons for using checklist method
1. Useful in summarizing information to make it
accessible to specialists from other fields
Impact Assessment Methods
Matrix method
Method is developed initially by Leopald et. al.,
(1971)
A ‘simple interaction matrix’ is formed
• where project actions are listed along one axis, say,
vertically downward
• and environmental impacts are listed along the other
axis, say, horizontally
Such a matrix allows us to identify the cause-effect
relationships between various actions and the
environmental impacts associated with them
Impact Assessment Methods
Matrix method
The steps involved in this method are:
Identify all the actions that are part of proposed project
and the impacts of these actions
Describe the impact interaction in terms of its
magnitude and interaction
Sum the products of the all ‘magnitude’ and
‘importance’ ranks across the rows and columns of the
matrix
All rows or columns sum will give an overall
measurement of the impact score for the project
Impact Assessment Methods
Matrix method
‘Magnitude’ of an interaction is its extensity or scale
marked in terms of a number from 1 to 10
• where 1 represents a small magnitude
• 10 represents a large magnitude
Scale of importance also varies from 1 to 10
• 1 represents a very low importance
• where 10 represent a severe impact of highest
importance
Impact Assessment Methods
Matrix method
Assignment of magnitude ranks
• will be based on an objective evaluation of facts
related to the anticipated impact
Assignment of importance weights
• will be based on subjective judgment of the
individuals, small groups, or interdisciplinary team
working on the assessment study
Impact Assessment Methods
Matrix method
Adavntage :
An important application of the matrix method is to
evaluate alternatives from the point of view of
decision-making
Limitation
Fails to take into account the incremental
differences in impact magnitudes for ranking
i.e. there is no proportionality in ranks when
magnitudes are changing
Case study: ENVIRONMENTAL IMPACT ANALYSIS : A CASE
STUDY OF ACC CEMENT PLANT
