Land Contamination Management &

Site RemediationBy :

Mr Manas Orpe

(BE Chemical Engineering)

Under the supervision of:

Prof K N Bawankar

Department of Chemical Engineering,

AISSMS College of Engineering, Pune-1

By :

Mr Manas Orpe

(BE Chemical Engineering)

Under the supervision of:

Prof K N Bawankar

Department of Chemical Engineering,

AISSMS College of Engineering, Pune-1

12/04/23 1

Contents

• Pollution and Contamination• Land Contamination• Health Effects• Site Remediation Steps• Risk Assessment• Options Appraisal• Verification Plans• Implementation of Strategy• Remediation Technologies• PIL• Conclusions• References

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Pollution and Contamination

• In short, there is very little difference between Pollution and

Contamination, especially in environmental terms.

• Pollution can be considered to be something which is not

welcomed in the environment. Contamination is more often

used to refer to a substance which has been introduced to

another substance, generally giving an adverse affect.

• Pollution clean-up / remediation of soils or water would

involve exactly the same actions as Contamination clean-up /

remediation.12/04/23

3

Land Contamination

• Defined as the introduction of a substance into the land so that its quality and function are adversely affected.

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Health Effects

• Chronic exposure to chromium, lead and other metals,

petroleum, solvents, and many pesticide and herbicide

formulations can be carcinogenic.

• Chronic exposure to benzene at sufficient concentrations is

known to be associated with higher incidence of leukemia.

• Organophosphates and carbomates can induce a chain of

responses leading to neuromuscular blockage.

• Mercury linked to higher incidences of kidney damage.

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Site Remediation Steps

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Risk Assessment

• The purpose of preliminary risk assessment is to develop an

initial conceptual model of the site and establish whether or

not there are potentially unacceptable risks.

• Information collection may include:

i. Desk study

ii. Site reconnaissance

iii. Additional desk study and exploratory site investigation

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Options Appraisal

• A feasible remediation option is one that is likely to meet

defined, site-specific objectives relating to both the pollutant

linkage and the wider management context for the site as a

whole.

• The purpose of this stage of options appraisal is to develop a

remediation strategy capable of practical implementation on

the site and to describe in broad terms the characteristics of

that strategy.

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Verification Plan

• It is a document that gives requirements for gathering data to

demonstrate that remediation meets the remediation

objectives and remediation criteria.

• It includes sampling and testing criteria( eg. field monitoring

data, analytical data, level surveys above and below capping

layers).

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Implementation Of The Remediation Strategy

• Deals with all aspects of the design, preparation,

implementation, verification, and long-term monitoring and

maintenance of remediation.

• Elements of design are passed onto the specialist sub-

consultants or contractors, the design needs to also be

subject to proper checking and quality assurance procedures.

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Remediation Technologies

• Remediation technologies are many and varied but can be

categorized into ex-situ and in-situ methods.

• The more traditional remediation approach consists primarily

of soil excavation(disposal to landfill “dig and dump”)

and groundwater(pump and treat).

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Excavation or dredging

• Excavation processes can be as simple as hauling

the contaminated soil to a regulated landfill.

12/04/23 12Fig. 1 Excavated Area

SEAR-surfactant enhanced aquifer remediation

• Also known as Solubilization and recovery, the Surfactant

Enhanced Aquifer Remediation process involves the injection

of hydrocarbon mitigation agents into the subsurface.

• In geological formations that allow delivery of hydrocarbon

mitigation agents, this approach provides a cost effective and

permanent solution.

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• This technology is also successful when utilized as the initial

step in a multi faceted remedial approach.

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Contd.

Solidification and Stabilization

• Stabilization - involves the addition of reagents to a

contaminated material (e.g. soil or sludge) to produce more

chemically stable constituents.

• Solidification - involves addition of reagents to impart

stability to contain contaminants in a solid product and

reduce access by external agents (e.g. air, rainfall).

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However, the uptake of S/S technology has been relatively modest, and a number of barriers have been identified including:

•the lack of authoritative technical guidance on S/S;

•uncertainty over the durability and rate of contaminant release

from S/S-treated material;

•experiences of past poor practice in the application of cement

stabilization processes used in waste disposal in the 1980s and

1990s; and

•residual liability associated with immobilized contaminants

remaining on-site, rather than their removal or destruction.12/04/23 16

12/04/23 17Fig. 2 Solidification and Stabilization

Pump and Treat

• Pump and treat involves pumping out contaminated

groundwater with the use of a submersible or vacuum pump

and then treating it.

• For petroleum-contaminated sites this material is

usually activated carbon in granular form.

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• It is expensive and a very slow process.

• Other methods include trying to increase the dissolved

oxygen content of the groundwater to support microbial

degradation of the compound.

12/04/23 19Fig. 3 Pump and treat

Soil vapor extraction

• SVE utilizes different technologies to treat the off-gas volatile

organic compounds (VOCs) generated after vacuum removal

of air and vapors (and VOCs) from the subsurface.

• Carbon is used for low (<500ppm) VOC concentration,

oxidation is used for moderate (up to 4,000 ppm) VOC

concentration, and vapor condensation is used for high

(>4,000 ppm) VOC concentration.

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• Vapour condensation involves cryogenically cooling the vapor

stream to below 40 degrees C such that the VOCs condensate

out of the vapor stream and into liquid form where it is

collected in steel containers.

• This recovered chemical can then be reused or recycled in a

more environmentally sustainable or green manner.

• This technology is also known as cryogenic cooling and

compression (C3-Technology).

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12/04/23 22Fig. 4 Soil Vapour Extraction Technique

Public Interest Litigation

• Riverine pollution by tanneries, industrial effluents, and

untreated sewage;

• Soil and groundwater pollution;

• Indiscriminate mining;

• Protection of forests;

• Fencing of parks and sanctuaries;

• Preservation of monuments of archaeological and historical

significance and their protection from vandalism; and

• Automobile pollution.12/04/23 23

Fines and Closure Notices

Examples :

•Manufacturer of potassium and sodium bichromate (Gujarat)

•Dyeing units located in Tirupur, Tamil Nadu

•Steel manufacturing facility, Kalmeshwar, Maharastra

•Manufacturing facility located in Aurangabad

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Conclusions

• Despite the absence of a concise regulatory framework to

deal with polluted sites in India, PILs have given the judiciary

enormous scope for intervening in environmental matters

and passing severe penalties against companies that have

been found guilty.

• As for the technologies for remediation, they are expensive

but need to be done for the environmental health and safety.

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References

1. Mary Harris, Judith Lowe, Phil Crowcroft & Casella Stanger, “Contaminated land report, Model Procedures for Management of Land Contamination”, 2008

2. The Water Act (Prevention and Control of Pollution) 19743. Hazardous Wastes (Management & Handling)

Amendment Rules, 20034. Ravi Costa and Sanjay Sampath, “India: Environmental

Liability and Contamination Regulations”, EHS Journal, 2011

5. Snyder C., "The dirty work of promoting "recycling" of America's sewage sludge“, Int J Occup Environ Health, Issue(4)(2005), 415–427

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THANK YOU

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