The document discusses environmental remediation. It explains that remediation projects generally involve 5 phases: investigating contamination, characterizing the nature and extent of impacts, evaluating cleanup alternatives, implementing remedial actions, and documenting goal achievement. It notes complicating technical, political, and economic factors can make remediation difficult. The document also describes the 4 phases that environmental contaminants can partition into: vapor, adsorbed, free product (NAPL), and dissolved phases. Contaminants exist in these different phases depending on their physicochemical properties and site characteristics, determining their distribution, fate, transport, and difficulty of removal.

1. CE-355 environmental Management
Lecture# 03
(7th semester Civil)
By: Engr. Hayat Hussain
Lecturer Saidu polytechnic institute saidu sharif Swat

2. Content
• Fundamental of Environmental Remediation
• Four Phases of Environmental Contamination

3. Fundamental of Environmental Remediation
The remediation projects are often categorized by legislative program under
which they are being performed.( i.e. RCRA,CERCL, or voluntary cleanup
program). The type of activities that must be performed are essentially the same
for each type of project, yet the names of the various projects stages and tasks
change based on the legislative program. regardless of the name applied to
various project tasks, they are performed in order to
1. Determine if any release have occurred with required further investigation
2. Characterized the nature and extent of impact as well as the rate of
contaminant migration
3. Evaluate cleanup alternative, including cleanup standard, and select
appropriate remediation technologies.
4. Implement remedial actions, including system installation and operation (if
necessary).
5. Documents that intended goals have been achieved and discontinue remedial
actions( project closure).

4. On the surface, it would appear that this would be rather straightforward
process. Individuals relatively new to environmental remediation might be able
to guess the areas of potential project saving such as:
▪ Performed only enough investigation to characterize the site physically and
understand the nature and extent of environmental impacts.
▪ Establish clean up targets which protective of human health and environment
; do not clean up any more than is necessary.
▪ Select the remediation technologies that are most cost efficient in achieving
established cleanup goals.
▪ Implement remediation technologies in the most cost-efficient manner
possible.

5. Unfortunately, industry experience indicates that is much easier said
than done due to number of complicating factors. These complicating
factors, which include technical, political, and economic components.
Before discussing these complicating factors, it is necessary to review
some fundamental concepts regarding the fate and transport of
environmental contaminants and the relative ease by which they can
removed or destroyed. In addition, a brief review of investigation
techniques and remediation technology is provided.
5

6. The four phases of environmental contamination
The variety of contaminants that can be released to the subsurface environment include
organic compounds ( volatile and semi-volatile), inorganic compounds, and elements. Each
contaminant has its own distinct set of physicochemical characteristics that govern its behavior
in the environment. In addition, each site has its own set of subsurface characteristics,
hydrogeological and geochemical, which interact with the contaminant characteristics to
ultimately determine contaminant distribution, fate, transport, and ease of removal/destruction.
An important fundamental concept in environmental remediation is contaminant partitioning.
Contaminants partitioning refers to the separation of the total mass of release contaminants
into the various phases in which they may exist in the environment. Before continuity, the
word “phase” and “component” should be defined. For our purposes, a phase can be define as:
Any physically distinct part of a system that is separated from the other parts of the system
define bounding surfaces.
Therefore gasoline floating on the top ground water can be referred as a separate liquid phase.
The word “component refers to
The individual constituent which sum together to compose a phase.
Referring again to gasoline, although a separate liquid phase may be observed, this phase is
made up of large number of organic component.

7. Four phases of environmental contamination
When organic compounds are released to environment, they will
partition themselves into four distinct phases:
❖Vapor phase, within the nonliquid-filled pore space of soil or distinct
bubbles within the liquid-filled pore spaces.
❖Adsorbed phase, adhered to the soil particles.
❖Free product, or non aqueous- phase liquid (NAPL), not adhere to soil
and as a distinct separate phase.
❖Dissolved phase, with in the ground water.

9. QUESTIONS & ANSWERS

10. Thanks