University of Dar es Salaam

Environmental Impact Assessment

Presenter: Dr. Juma Mohamed (PhD)

B.Sc., M.Eng. Mngt, PhD Eng. Mngt

January 2021
 Environmental
Impact Assessment
 Outline of the Talk

3.2.1.Introduction: Recall: What is Environment?

:What is environmental impact?
3.2.2 What is environmental Impact Assessment?
3.2.3 Historical Background of EIA
3.2.4 The Process of Environmental Impact Assessment
3.2.5. Tools and Methods
3.2.6 EIA and Project Life Cycle
3.2.7 Environmental impact statement
3.2.8 Limitations and benefits of EIA
 3.2.1What is Impact and
Environmental Impact?

• An impact is the effect of one thing

upon another

• change in an environmental
parameter, over a specified period
and within defined area, resulting
from a particular activity compared
with the situation which would have
occurred if the activity had not been
initiated

• negative or positive, direct or

indirect, short term or long term,
Nature of environmental impact
 3.2.2 What is Environmental Impact
Assessment?

• -the process having ultimate objective of providing

decision makers with an indication of the likely
consequences of their actions (Davies et al., in
Wathern, 1998).

• the official appraisal of the likely effects of a

proposed program or project on the environment,
alternatives to the proposal and measures to be
adopted to protect the environment( Gilpin, 2000)

• -The process of identifying the likely consequences

for the biogeochemical environment and for man’s
health and welfare of implementing particular
activities and for conveying this information, at a
stage when it can materially affect their decision, to
those responsible for functioning the proposals.
(Munn 1979 in Wathern, 1998).
 Therefore Environmentally
Impact Assessment is
A formal process for identifying:
• likely effects of activities or projects on the
environment, and on human health and
welfare.
•means and measures to monitor & mitigate
these impacts

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 Objectives of EIA
• Protection and management of the environment
for sustainable development;
• Integration of environmental management and
economic decisions at an early planning stages;
• To predict the consequences of a proposed
project in terms of environmental, social,
economic and cultural and propose mitigation
measures.
• To compare available alternatives for a
particular project and determine the optimum mix
of environmental and economic costs and benefits;
• To involve public, proponents, private and
government agencies in assessment and review
of a proposed project in an open, transparent and
participatory approach.
 Elements of EIA

• Screening:- decide if EIA is

required based on the data
collected.
• Scoping:- identify key issues and
concerns of interested parties.

• Identifying and Evaluating

Alternatives:- list alternative sites,
techniques and impacts of each.
• Mitigating measures:- review
 3.2.3 Historical Background of EIA
Cuyahoga River burns in
1966 (3rd time). Cleveland,
Ohio, U.S.
1960s & 70s:
Environmental crisis
affects all industrialized
economies
EIA is one response:
1952 “Killer fog” kills 4,000 in
London
First national EIA
1963 Silent Spring documents
the effects of DDT
requirements:
Etc. . . 1969 US National
Environmental Policy Act
(NEPA) requires EIA for US 10
3.2.3 Historical Background of EIA
CONT..
• 1972, the UN Stockholm conference
on Human Environment- declaration
of 26 principles on sustainable
development and EIA

• The 1992, UN conference on

environment and development in Rio
de Janeiro. The declaration of 27
principles was endorsed whereby
principle 17 is devoted to the
National Instrument of EIA.
 3.2.4.The Process of EIA

1. Project or Investment/Development
description
– Describe the nature, scope and purpose of
the project/investment;
– Describe physical characteristics (size, number of
employees, infrastructure required) of a project;
– Describe operational properties (type and quantities
of raw materials, energy used and other natural
resources);
– Describe nature of emissions (liquid, gaseous and
solid waste).
2. Alternative considered
– Describe all alternative sites and reasons for final location;

– Focus on alternative plant design and explain reasons for

final selection;

– Describe on product and process design.

3. The Baseline Environmental
Criteria
– Collect human population and their properties;
– Describe present human use of the site;
– Nature of fauna, flora and habitats;
– Explain quality and quantity of surface and
groundwater;
– Air, soil quality and climatic factors;
– Explain landscape and topography of the site;
– Explain nature of the built environment;
– Any other relevant environmental features.

4. Assessment of Environmental
Impact
– Assess effects on physical, social and economic;
– Assess all direct and indirect effects;
5. Mitigating Measures
Could be in terms of:
– Site location and orientation;
– Type of process selected;
– Any equipment incorporated to control, contain and
treat wastes;
– Any measures taken to protect surroundings.

6. Contingency Measures
– Risk assessment such as accident;
– Indicate preventive measures to be adopted in such
accidents;
– Assessed in terms of technology and techniques used.

7. Assessment of Difficulties
– Offer difficulties associated in data collection and
analysis, prediction of effects and assessment of risks
in the whole exercise of EIA.
8. Environmental Impact
Statement (EIS)
– Results of EIA are presented within EIS;
– EIS include findings of environment impact of a
proposed project and/or alternatives and mitigating
measures (and their assessment);
– EIS is required for discussion from both competent
authorities and public.
9. Public Comments
– Invite public comments on the proposed project;
– Incorporate public opinions into the proposed project
design;
– Modify the proposed project design in case of
disagreements relating to development. A
compromise between developers and public is vital.
10. Planning Authority
– Planning authorities have mandate to accept or reject any
development based on EIA conducted;
 Steps in the EIA Process

- Project Screening - is an EIA needed?

- Scoping - which impacts and issues to be considered?
- Description of the project/action and alternatives
- Description of the environmental baseline
- Identification of key impacts

- Prediction of impacts
- Evaluation and assessment of significance of impacts - Public Consultation
- Identification of mitigation measures

- Presentation of findings in an Environmental Statement

(including a non-technical summary)

- Review of Environmental Statement

- Decision-making

- Post-decision monitoring
- Auditing of predictions and of mitigation measures
Step by Step
Flowchart
 REGISTRATION

No EIA Preliminary EIA PRELIMINARY

Required
SCREENING Required ASSESSMENT
SR

IMPACT ASSESSMENT
PER for Scoping
full EIA TOR
EIA Study
PER
Revised EIS

Public Hearing Required

REVIEW
EIS
Revision EIS, SR
PER Public Hearing Report PUBLIC
HEARING

EIS/PER Revision PERMITTING EIS/PER Not Approved

DECISION

EIS/PER EP
Approved DECLINED

EIS FINALIZED

NEMC Action

EP
ISSUE Proponent Action

Public Action
IMPLEMENTATION
NEMC Decision

ER SR Screening report
MONITORING PER Preliminary Environmental Report
TOR Terms of Reference
EAR EIS Environmental Impact Assessment
AUDITING EP Environmental Permit
ER Environmental Report
EAR Environmental Auditing Report
DR
DECOMMISSIONING DR Decommissioning Report

Figure 4.1 EIA Procedure in Tanzania, (NEMC)

Assessment of Environmental Impacts
• Type and nature - from biophysical to socio-economic
• Significance - sometimes small impacts can be highly
significant - e.g. disturbance of nesting of pair of endangered
birds
• Extent - local to global
• Timing - immediate or some time later (e.g. exposure to
carcinogenic chemicals can be responsible for cancers 30 years
later)
• Duration - short term (e.g. construction noise) to permanent
(e.g. relocation of a village)
• Uncertainty - depends on the likelihood and consequences of
the impact occurring
• Reversibility - some impacts are reversible (e.g. rehabilitation
following decommissioning), others may be irreversible (e.g.,
CO2 emissions from vehicles)
Assessing Significance
e.g, Loss of
e.g. Loss of
a Nationally
a local
important
Nature
Site of
Conservatio
Special
n area
Scientific
Interest

e.g., Indirect
impact on
national
SSSI
 3.2.5 EIA Tools and Methods
• Checklists,
• Matrices,
• Networks,
• Overlays (GIS-Geographical Information Systems)
• Expert systems
• Professional judgment

The choice of methodology can depend upon a

number of factors including; the type and size of the
project; the type and number of alternatives being
considered; the nature of the likely impacts; the
availability of impact identification methods; the
experience of the EIA team with their use; and the
resources available – cost, information, time,
personnel
 Checklist

• Checklists annotate the environmental

features or factors that need to be
addressed when identifying the
impacts of projects and activities.
• Simple checklist

• Structured methodology or system

– assign significance by scaling and weighting the
impacts, such

• Sectoral checklists- certain type of

projects.
 Matrices

• A matrix is a grid – like table that is used

to identity the interaction between
project activities, which are displayed
along one axis, and environmental
characteristic, which are displayed along
the other axis.

• impact severity = {ticks or symbols can

identify impact type (such as direct
indirect, cumulative) pictorially; numbers
or a range of dot sizes can indicate scale;
and descriptive comments }
 A Sample of Impact Matrix
DIRECTION DURATION LOCATION MAGNITUDE EXTENT SIGNIFICANCE

ACTIVITY/IMPACT Indire
Pos Neg Long Short Direct c Major Minor Wide Local Large Small
t

1. Wastewater
Treatment

Odour x x X x x x

Solid waste x x X x x x

Air pollution x X X x x x

2. Effluent

Water quality x X X x x x

Overloading of the
drainage x x x x x x
canal

Overloading of the
Msimbazi x X X x x x
River
 Networks

• For illustrating impacts relationships and

consequences .={ the causal-effect relationships
of project activities and environmental
characteristic}

• Useful in identifying and depicting secondary

impacts =impact hypotheses

• When used in conjunction with other methods,

simplified networks help to ensure that
important second-order impacts are not omitted
from the investigation.

• More detailed networks are visually

complicated, time-consuming and difficult to
produce unless a computer programme is used
for the task.
 Overlays-GIS
• Map impacts spatially and display then
pictorially= environmental sustainability analysis

• Topographic features, ecological value and

resource constraints = individual transparencies
and then aggregated into a composite
representation of potential impacts.

• significant for comparing site and planning

alternatives, for routing linear developments to
abstain environmentally sensitive areas and for
landscape and habitant zoning

• GIS=The computer – based - a modern version of

the overlay method. = stores, retrieves,
analyzing, modeling and and displays
environmental data in a spatial format.
Core impact area (CIA) & Area of Influnce (AF)
528600 528800 529000 529200 529400 529600 529800 530000 530200 530400
9246800

9246800
N

W E
9246600

9246600
S
9246400

9246400
9246200

9246200
#
9246000

9246000
LEGEND
9245800

9245800
0 - 250

250 - 500

500 - 1000
9245600

9245600
Contour

Stream

Roads/Path

#
9245400

9245400
Sound source

528600 528800 529000 529200 529400 529600 529800 530000 530200 530400

400 0 400 800 Meters

Noise Surface Map
 Expert systems

• computerized knowledge-based systems, used to

assist diagnosis, problem solving and decision-
making
• screening and scoping procedures = automated
using a number of rules and a data system that
encodes expert knowledge and judgment
• The user has to answer a series of questions that
have been systematically developed to identify
impacts and determining their mitigability and
significance
• expert systems are information – intensive, high
investment method of analysis.
 Professional judgment

• Professional judgment or expert opinion is

widely used in EIA, although not strictly a
formal method

• Knowledge and expertise gained in EIA work

can be used to systematically develop data
banks, technical manuals and expert systems,
=assisting in future projects.

• the successful application of the formal

methods of impact identification explained
above rests upon profession experience and
judgment.
 Advantages and Disadvantages of EIA
Methods
METHODOLOGY ADVANTAGES DISADVANTAGES
Checklists -Easy to understand and use -Don’t distinguish between
-Good for site selection and direct and indirect impacts
priority setting -Don’t link action and impact
-Simple ranking and The process of incorporation
weighting values can be controversial
Matrices -Link action to impact -Difficult to distinguish direct
-Good method for displaying and indirect impacts
EIA results -Have potential for double
counting of impacts
Networks -Link action to impact -Can be become very complex if
-Useful in simplified form for used beyond simplified
checking for second version
order impacts
-Handles direct and indirect
impacts
Overlays- GIS -Easy to understand -Can be cumbersome
-Focus and display spatial Poorly suited to address impact
impacts duration or probability
-Good siting
Computer Expert -Excellent for impact -Heavy reliance on knowledge
system identification and spatial -Often complex and expensive
 Resource requirements

• Qualified multi-disciplinary staff

skilled manager ,
trained specialists(-environmental science,
development planning, economics, waste and
pollution control, process engineering, landscape
design, social workers, environmental information

• Information about the environment

Biophysical Economic and social data

• Technical Guidelines
agreed with the competent authority; for carrying out
the various phases

• Other Resources
laboratory , library research, data manipulation and
processing, administrative resources the
 3.2.6 EIA AND THE PROJECT LIFE CYCLE
EIA occurs across the project
lifecycle proactively

1.Implementing mitigation measures

2. Build capacity for environmentally sound operation

Operate
Feasibility Design Construct
(may include handover) Reinvestment

1. Implement & maintain proper

operation
Environmental screening,
2.Environmental Monitoring and post
initial assessment and
scooping and detailed audit
EIA

33
 3.2.7 Environmental Impact
Statement (EIS)
• =A document prepared by a proponent, consultant, or
developer describing a proposed policy, program or project,
alternatives to the proposal and measures to be adopted to
protect the environment

• EIS is required before a new project can proceed.

• EIS for national environmental agency or authority, the

donor's environmental team, environmental consultants, the
implementing agency, the borrower and the general public

• EIS= maps, plans, tables, graphs diagrams = easy

appreciation of contents
 EIS CONTENTS-
• Executive Summary,
• Introduction,
• Compliance with policy, legal and administrative
framework,
• Project description and description of the
environment.
• public participation,
• Analysis of environmental impacts
• Environmental management and Monitoring plan
• Conclusion and recommendations
• References , appendices of relevant materials.
3.2.8. Benefits of Environmental impact assessment
• Maximum environmental and financial
benefits if EIA was carried out voluntarily
• Operational benefits e.g. improved
environmental performance, basis for
development of physical needs
• Short payback periods of the project
• EIA can be used to modify and improve
project design.
• Can ensure that project related resources
are used effectively/efficiently
• EIA ensures incorporation of social and
health aspects (e.g. worker migration,
housing, education impacts, etc.)
• Helps with identification of measures for
monitoring and managing impacts (including
mitigation).
3.2.9. limitations of Environmental
impact assessment
• Scientific expertise → may not
be available internally thus
external expertise which is
expensive
• Increased costs of a project
• Full range of alternatives
(including no development)
not always considered
• Difficult to develop effective mitigation
 Making EIA effective
EIA is undertaken early enough to
–a integral part of the affect project design

project development Mitigation and monitoring

developed in the EIA process is
cycle. implemented.

The full EIA study must consider real

–Honest alternatives
Impacts must be assessed honestly.

–Transparent & accessible The EIA products must be clear and

accessible to key actors.

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Questions and discussions !!!!!

Thank You