ENVS402 – Environmental Impact Assessment
7. Environmental Impact
p
Mitigating measures
I.
Benefit enhancing measures (selection
and implementation)
II. Adverse Impact mitigating measures
(selection and implementation)
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9/16/2011
ENVS402 EIA by Dr. Subodh Sharma
7. Environmental Impact
p
Mitigating
g
g measures
The purpose of mitigation measures is to avoid, reduce or minimize unwanted impacts and enhance beneficial impacts
impacts and enhance beneficial impacts
Selection of alternatives is also a form of Selection
of alternatives is also a form of
mitigation in terms of impact, cost and technology
gy
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ENVS402 EIA by Dr. Subodh Sharma
9/16/2011
Definition of mitigation
Mitigation
g
is.. . .
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The implementation of measures
designed to reduce the
undesirable effects of a
proposed action on the
environment
Mitigation is a key part of the
EIA process. It is essential to
achieving environmentally
sound
d design.
d i
Source: ENCAP EA-ESD
Course: Mitigation &
Monitoring
Different types of mitigation measures act in different ways to reduce
adverse impacts:
Type of measure How it works
Fullyy or partially
p
yp
prevent an
impact/reduce a risk by:
Prevention &
Control measures
ƒ Changing means or
technique
ƒ Changing the site
ƒ Specifying operating
practices
Examples
PREVENT contamination of
wells, by SITING wells a
minimum distance from latrines.
Implement health education
program
Initiate public awareness prog.
Compensatory
measures
Offset adverse impacts in
Plant trees in a new location to
one area with improvements COMPENSATE for clearing a
elsewhere
construction site.
Remediation/
Corrective
measures
Repair or restore the
Re-grade and replant a borrow
environment after damage is
pit after construction is finished
done.
ENCAP EA-ESD Course: Mitigation & Monitoring
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Example of Mitigation:
O
Operating
ti practices
ti
t preventt & control
to
t l impacts
i
t
y Irrigation
y Potential impact:
salinization of soils
y Mitigation: avoid
water-logging by using
improvedd on-farm
f
water
management, including
pplacement of drainage
g
structures.
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ENCAP EA-ESD Course: Mitigation & Monitoring
Example of Mitigation:
Change of site to prevent & control impacts
y Rurall road
d construction
y Potential impact: route
traverses nesting area for a
threatened species of bird
y Mitigation:
Re-route roadd to avoidd
nesting site.
Also,, minimize
construction noise and
other disturbance during
nesting season
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ENCAP EA-ESD Course:
Mitigation & Monitoring
Reliability of mitigation measures:
site & technique changes vs. operating practices
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PREVENTION of impacts by
changes to site or technique is
the most reliable approach to
mitigation.
CONTROL of impacts with
operating practices is less
reliable,, because the practices
p
must be continued after handover of the activity.
ENCAP EA-ESD Course:
Mitigation & Monitoring
Do I mitigate EVERY impact?
NOT NECESSARILY.
NECESSARILY
Mitigation is directed at two targets.
1 serious impacts
First, the most serious
impacts
p
identified by
y
the EIA process should
ALWAYS be mitigated.
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2
easily mitigated
impacts
After addressing the
most serious impacts,
there may be small
impacts for which
mitigation is easy and
low-cost. ENCAP EA-ESD Course:
Mitigation & Monitoring
7. Environmental Impact
p
Mitigating
g
g measures
A Framework of Impact Mitigation
Desirable
AVOIDANCE
MITIGATION
COMPENSATION
Alt. Sites/Technology
Actions
Use as last resort
Undesirable
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ENVS402 EIA by Dr. Subodh Sharma
9/16/2011
7. Environmental Impact
p
Mitigating
g
g measures
Characteristics of Impact Mitigation Measures
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Proposed mitigation measures should be able to describe;
1 the impact it will avoid, mitigate or compensate 1.
the impact it will avoid mitigate or compensate
when implemented,
2. an assessment of the effectiveness of protection measures,
3. the next best alternative,
4. the cost of the protection measures,
p
,
5. and the implementation plan for putting the measure into practice.
ENVS402 EIA by Dr. Subodh Sharma
9/16/2011
7. Environmental Impact
p
Mitigating
g
g measures
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ENVS402 EIA by Dr. Subodh Sharma
9/16/2011
7. Environmental Impact
p
Mitigating
g
g measures
Implementation of Mitigation Measures
Implementation of Mitigation Measures:
• should be cost effective and locally applicable and can be proposed during different stages of project implementation
proposed during different stages of project implementation.
•
•
•
•
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Pre‐construction (such as compensation for land acquisition),
Construction (such as planning and designing activities)
Construction (such as planning and designing activities),
Operational stages (such as maintenance activities).
The cost is usually about 10 % of the total cost of the project The
cost is usually about 10 % of the total cost of the project
(although it depends on the nature, size, location etc. of the project)
ENVS402 EIA by Dr. Subodh Sharma
9/16/2011