The document outlines the Environmental Impact Assessment (EIA) procedure, detailing three key elements: impact identification, evaluation, and mitigation planning. It specifies six steps in the EIA process including preparatory works, data collection, analysis, impact evaluation, mitigation planning, and report preparation, emphasizing the importance of assessing both positive and negative impacts on the environment. Various methods for conducting EIA are discussed, including checklists, matrices, flowcharts, and mathematical modeling, with considerations for project type, impact nature, and public involvement.

1. EIA Procedure
9 August 2018

2. EIA Procedure
2
Three sequential elements: EIA process
 Identifying of all positive and negative impacts on Nature and Human
Environment resulting from the proposed project.
 Evaluation or assessment which includes quantification of the identified
impacts with respect to a common base and with respect to impacts from
other project actions.
 Preparation of a mitigation plan which upon implementation will reduce or
offset the potentially significant negative impacts of the project to acceptable
levels.

3. Three overlapping stages of Impact Analysis
Identification-

identifying impacts associated with each phase of the project and the
activities undertaken
Prediction-

forecasting the nature, magnitude and extent and duration of the major
impacts
Evaluation-

determining the significance of the residual impact i.e., after taking into
account how mitigation will reduce the significant impacts.

4. 5
Information required to establish baseline conditions
 current conditions (baseline)
 current and expected trends
 effects of proposals already being implemented
 effects of other proposals yet to be implemented
Introduction to Impact Analysis

5. 6
Impact characteristics can vary in:
 nature (positive/negative, direct/indirect)
 magnitude (severe, moderate, low)
 extent/location (area/volume covered, distribution)
 timing (during construction, operation etc., immediate, delayed)
 duration (short term/long term, intermittent/continuous)
 reversibility/irreversibility
 likelihood (probability, uncertainty)
 significance (local, regional, global).
Introduction to Impact Analysis

6. EIA Procedure: Steps
7
Step 1: Preparatory Works
 Study the IEE report carefully
 Identifying the area of influence by the project
 Delineate the major environmental parameters required in-depth study
 Identifying the criteria for measurement of environmental alterations.
Step 2: Data Collection
 Collect information related to the project from all possible secondary sources
 Conduct field survey to collect primary data regarding existing physical, ecological
and socio-economic conditions
 Collect opinion of well informed local people and beneficiaries (Public
Consultation)
 Develop questionnaires to acquire necessary field data.
Step 3: Data Analysis
 Convert qualitative and quantitative field assessment to values indicating
magnitude of environmental changes
 Make independent quantification, if EIA team consists of more than one member
and then make the average value.

7. 8
EIA Procedure: Steps
Step 4: Impact Evaluation
 Put the values indicating magnitude of environmental changes from Fig 4.1 and
corresponding importance or weight of environmental parameters influence by the project
from Fig. 4.2 in the appropriate columns in Table 4.2, 4.3 and 4.4 depending on the type of
projects and multiply them to obtain positive and negative impact of the parameters.
 Sum up all these impacts as illustrated in Table 4.2 to obtain the Environmental Impact
Values (EIVs) of major components or of the total project.
 Also complete evaluation of impacts of all project alternatives.
Step 5: Mitigation and Monitoring Plans
 Put more attention to parameters producing negative EIVs and identify the mitigation
measures to be incorporated in the planning and implementation stags of the project to
eliminate, reduce and offset the negative impacts and thereby enhancing the net positive EIV
(benefit of the project)
 Plan a EMP including the monitoring plan.
 A list of mitigation measures against potential impact need to be developed.
Step 6: Preparation of the Report
Following the specific format as mentioned in the ToR or as per Standard Format.

8. 9
Figure 4.1. Magnitude of Environmental Changes

9. 10
Relative
importance of
environmental
parameter

10. 11

11. Example: EIV
-19
-13
12

12. Example: EIV (continued)
+27
-3
13

13. 14
Example
To find out the possible environmental impacts an EIA was performed for a “Lather Industry” which will be
established near Turag river. A total no of 150 people were participated in the survey. Find out the Total EIV in a
tabular form from the following information and comment about the results whether it should be established or
not. In parentheses relative importance factor are given.
Ecological Impact:-
Fisheries [10]: 55 people answered severe negative impact, 50 people answered higher negative impact, 30
people answered moderate negative impact and 15 people answered very low negative impact.
Tree plantation [5]: 40 people answered higher negative impact, 60 people answered very low negative impact,
and others answered no change of environment.
Wetland [1]: 100 people answered no change, 20 people answered moderate negative impact, and 30 people
answered very low positive impact.
Physio-chemical:-
Drainage Congestion [5]: 45 people answered low negative impact, 65 people answered very low negative impact,
and the remaining people answered no change.
Obstruction to waste water flow [4]: 60 people answered moderate negative impact, 20 people answered very
low negative impact and remaining answered no change.
Human Interest:-
Employment opportunities [8]: 75 people answered severe positive impact, 30 people answered higher positive
impact and 25 people answered low positive impact, and remaining answered no change.
Industrial activities [3]: All the people answered very low positive impact.

14. 15
EIA Methods
 Approach developed to identify, predict and value changes of an action
 Mechanisms by which information is collected and organized, evaluated and
presented
 Concerned with predicting the future states of environmental parameters and
may involve mathematical modeling.

15. 16
EIA Methods
Some common methods are:
 Checklists
 Matrices
 Networks/Flowcharts
 Cost Benefit Analysis
 EES (Environmental Evaluation System)
 Overlays/GIS

16. 17
Choice of a particular EIA method depends on:
 Type and size of proposed project
 Types of alternatives being assessed
 Nature of the likely impacts
 Experience in using the EIA method
 Time and resource availability for an individual EIA
 Nature of public involvement
 Experience of the proponent
 Procedural/administrative requirements
 Size, type and environmental structure of the area.

17. 18
Checklists
 Standard lists of the types of impacts associated with a particular type of project
 Primarily organizing information to ensure that no potential impact is overlooked.
 Should enable identification of impacts on
– Soil
– Water
– Air
– Flora
– Fauna
– Resources
– Recreation
– Cultural

18. 20
Example of a checklist

19. Questionnaire checklists:
Based on a series of questions to be answered related to the potential impacts of the
project. They may provide a scale for classifying the estimated impacts from highly
negative to highly beneficial. There are no guidelines or information on how the various
factors are to be measured.
Example of a questionnaire checklist
Disease vectors
–
Are there known disease problems in the project area transmitted through
vector species such as mosquitoes, flies, snails, etc.? (yes, no, or not known)
Are these vector species associated with:
–
aquatic habitat? (yes, no, not known)
–
forest habitats? (yes, no, not known)
–
agricultural habitats? (yes, no, not known)
Will the project provide opportunities for vector control through improved standards
of living? (yes, no, not known).

20. Example of a questionnaire check list for a hydropower project

21. Example of a descriptive checklist
Data Required Information Sources & Predictive Techniques
Nuisance
* Change in occurrence of odour, smoke,
haze, etc., and number of people affected.
Water quality
* For each body of water, changes in water
use, and number of people affected.
Noise
* Change in noise levels, frequency of
occurrence, and number of people bothered.
* Expected industrial processes and traffic
volumes, citizen surveys.
* Current water quality, current and expected
effluent.
* Current noise levels, change in traffic or
other noise sources, changes in noise
mitigation measures, noise propagation
model, citizen surveys.

24. Matrices
 Matrix methods identify interactions between various project actions and
environmental parameters and components
 Allow for the identification of cause-effect relationships
 Can address impact severity and significance
 Qualitative or quantitative estimates can be used
 A matrix of potential interactions is produced by combining these two lists (placing one
on the vertical axis and other on the horizontal axis).

25. Matrices
Is a grid-like table which shows interaction between:
–
project activities-displayed along one axis, and environmental indicators-displayed
along other axis.
“Entries” are made in the cells to highlight features related to the nature of the impact,
–
ticks or symbols can identify impact type
–
numbers or a range of dot sizes to indicate scale; or
–
descriptive comments can be made.

26. Types of matrices
Simple matrices
–
indicate that an impact is expected to occur, without reference to
magnitude or significance.
Complex /Interaction matrices
–
provide quantitative estimates of impact magnitude and
significance, and
–
can be combined with a weighting scheme leading to a total "impact
score" (used for significance as well)

27. Simple Matrix for the Pangani Falls Redevelopment Project (Tanzania)
Activity Impacts
Land clearance,
bulldozing
visual intrusion, acceleration of run-off, dust, noise,
diesel fumes, soil erosion, soil compaction, exposure
of sub-soil, silt to river, destruction of vegetation.
Stone crushing dust, noise, soil erosion, lethal hazard to workers
Traffic oily waste run-off, noise, hazard to pedestrians and
animals, dust to roadside
Impoundment of the
headpoint
inundation of swamp, loss of wetland vegetation, loss
of habitat for wildlife especially passerine birds;
desiccation of the riverbed between the headrace and
tailrace, alteration of the aquatic and riparian ecology,
scoring of riverbed downstream - changing the
environment for aquatic life
Road making, trenching noise, visual intrusion, dust, fumes, hard surfacing
causing alteration of drainage, acceleration of run-off
and reduced infiltration, soil erosion, soil compaction,
exposure of sub-soil, silt to river, contamination of
groundwater.

28. Simple matrices are useful:
 early in EIA processes for scoping the assessment;
 for identifying areas that require further research;
 for identifying interactions between project activities and specific environmental
components.
However, matrices also have their disadvantages:
 they tend to overly simplify impact pathways,
 they do not explicitly represent spatial or temporal considerations,
 they do not adequately address synergistic impacts.

31. Interaction matrix (Leopold Matrix)
An abstract presentation of an interaction
matrix.
Rows represent environmental elements.
Columns show the different project activities
for the construction and the operation phase
of the proposed project.

32. Leopold Matrix
A typical well-known example of an interaction matrix
The magnitude and importance of impacts can be expressed
using different symbols, colors or hatchings.

34. Networks / Flowcharts
Illustrate the cause-effect relationship of activities and environmental characteristics
Useful in identifying and depicting secondary impacts (indirect, cumulative, etc.)
Networks are capable of identifying
– direct and indirect impacts,
– higher-order effects and
– interactions between impacts and,
– hence are able to identify and incorporate mitigation and management
measures into the planning stages of a project.
Network diagrams may be used to illustrate linkages and higher order effects in the system.
Figure illustrates how secondary and higher order effects may be evaluated in cause effect chains.
A problem with this kind of diagrams is that it tends to become large and complex.
There are no quantitative measures on impact magnitude or significance.

35. Features of Network Method
The network analysis assessment method is based on the concept that there are links and
interaction pathways between individual elements of the environment, and that where one
element is specifically affected this will also have an effect on those elements which
interact with it identifies the pathway of an impact using a series of chains (networks) or
webs (system diagrams) between a proposed action and the receptor of an impact.
Cumulative impacts can also be identified in network and systems diagrams where
different actions or developments can affect the same environmental element or
receptor.

36.  The network approach was developed to consider the secondary, tertiary and higher-
order impacts that can arise from an initial impact.
 Impact networks are also useful to show cumulative impacts.
 The major strength of a network is its ability to identify pathways along which both
direct and indirect effects are produced, and its usefulness is in the consideration of
mitigating measures during the early stages of the project.
 Impact networks may become very complicated for large projects.
 Impact networks or graphs consist of logic operations.
Network Approach

37. A Network Diagram

38. A Network Diagram:

39. Networks/Flowcharts
Advantages:
 integrated assessment, instead of discipline by discipline
 inter-relations between causes and effects, including indirect impacts
 cumulative impact assessment – communication (when simple).
Disadvantages:
 complexity (especially visually complex)
 difficult to distinguish and quantify magnitudes (and importance) of different impacts

40. 42
Illustrates the geographical extent of different impacts using GIS mapping.
Each overlay is a map of a single impact.

saline effected areas, deforested areas, limit of a groundwater
pollution plume, etc.
The magnitude of the impact could be expressed using different shading
intensities, with darker shading representing a greater impact.
With such a composite of overlaid map sheets both the spatial distribution
and the magnitude of impacts could be easily demonstrated and
comprehended by interested parties.
Overlays- Geographical Information System (GIS)

42. Overlays and GIS

43. Mathematical Modelling
Is most useful for impact prediction
assesses both flow quantities and qualities
 (e.g, salt/water balances, pollution transport, changing flood
patterns)
 But, depend of quality data inputs.

44.  Expert systems or knowledge-based computer systems are
particularly useful when there is a shortage of expertise to conduct
the assessment.
 Such systems may also have potential for improving public
involvement.
 The approach is based on a computer programme that stores a
body of knowledge, the knowledge base.
 Special computer programmes called 'ínference engines' are used
to process this knowledge base and apply it to a particular problem
('knowledge rules')
Expert systems

45. 47
 A user helps to perform tasks that usually demand input from a
human expert. The user is presented with ‘questions’ developed
from existing knowledge, through an (user) interface.
 The expert system reviews the answer given to each question.
 If some of the information needed comes from existing data
instead of the user, a data base has to be connected to the system.
 The data base can also be used to store the output from the
system.
 Expert systems can be useful but cost a lot of time and expertise
to develop.
Expert systems

46. General structure of an expert system
Expert systems

47. 49
Main advantages and disadvantages of impact identification
methods

49. 51
Evaluation of Ecological Impact
 Ecological consequence of the activity
 Likelihood of occurrence of the activity
 Calculating the product of these two parameters.
Impact Significance
The significance of ecological impact is determined by calculating the
consequence and likelihood of occurrence of the activity, expressed as follows
Significance = Consequence × Likelihood

50. 52

51. 53