Advanced Geotechnical Engineering
ES4D8
Contaminated Land (Lecture 2)
Mohaddeseh Mousavi-Nezhad
Room:D211
Email:m.mousavi-nezhad@warwick.ac.uk
31/05/2016
The University of Warwick
1
Review
• Why is Contaminated Land important to YOU?
 Risk of hazard to human health & environment
 Contaminants in the ground can change the mechanical
properties of soil
• Basics & definitions & legislation
Classification of Lands
Status
status
Historical
 Brownfield Land
Vacant
 Greenfield Land
Under-used
Government encouraging redevelopment of Brownfield sites
31/05/2016
The University of Warwick
2
Review
• Pollution,
• Contamination
• Contaminated Land
Part IIA Responsibilities:
• Local authorities responsible for identifying potentially contaminated
sites in their area and investigating to determine if “contaminated land”
as defined in Part IIA. There is a public “record” / “register”.
• Local authorities can then serve a remediation notice.
• Mechanisms in legislation for forcing polluters to remediate or
• Local authorities may undertake remediation themselves and recoup
costs later.
• Environment Agency (EA) responsible for severely contaminated sites
i.e. “special sites”.
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The University of Warwick
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Introduction-Topics to be covered
• Concepts
• Legislation
• Parties involved
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Basics & Terminology
Most contamination is dealt with by the planning process.
Most planning permissions have a condition to investigate
contaminated land.
A typical example:
“No development shall commence on site until a risk based contaminated land
assessment has been submitted to and approved in writing by the Local Planning
Authority. The assessment should be carried out in accordance with BS 10175: 2001
“Investigation of Potentially Contaminated Sites Code of Practice” and CLR 11 “Model
Procedures for the Management of Land Contamination” issued by the Environment
Agency. Thereafter, the development shall be implemented in accordance with the
approved details and retained in perpetuity, unless otherwise agreed in writing by the
Local Planning Authority.”
Reason: To ensure the land is fit for purpose and to accord with the
aims and objectives of PPS 23.”
Basics & Terminology
Developers’ responsibility
 to demonstrate the site is NOT contaminated
 or demonstrate that significant harm is NOT being caused or there is
NO significant possibility of such harm being caused and that pollution
of controlled waters is NOT being, or un-likely to be, caused.
If this cannot be demonstrated, developer has to remediate the site.
This may be necessary even on greenfield sites.
Basics & Terminology
1st concept of “risk assessment”:
If naturally occurring compounds, or compounds from man’s
activities, are present in the ground or GW, there needs to be a
mechanism to determine whether they pose hazardous and
present a risk.
“risk assessment” is that mechanism.
Risk assessment can be:
 qualitative: without use of numbers, e.g. “low, medium or high”
risk
 semi-quantitative
 quantitative: assigning numbers to quantify the hazard and
exposure.
Basics & Terminology
2nd concept of “potential to cause harm”:
A substance is considered hazardous if it has the potential to cause harm.
Some every day examples:
• too much salt;
• too much alcohol;
• playing rugby;
• driving a car.
Some good or essential in small quantities.
But hazardous in larger quantities – they have potential to cause
harm.
Basics & Terminology
3rd concept of “harm”:
The legal definition of harm is:
“harm to the health of living organisms or other interference with
the ecological systems of which they form part and, in the case of
man, includes harm to his property”. [ Source: EPA (1990), Part IIA,
78A Preliminary ]
Significant harm to human health is defined as:
“death, disease, serious injury, genetic mutation, birth defects or
the impairment of reproductive functions”.
Basics & Terminology
4th concept of “source, pathway, receptor & a pollutant linkage”
a substance [ or contaminant ] that is in, on or under the land and
has the potential to cause harm [ to people, living organisms,
ecological systems ] or to cause pollution of controlled waters.
• e.g. contaminants in soil, groundwater and gaseous phase
Source: is the location or feature from which contamination is, or
was, derived. NB This could be the location of the highest
concentration of the contaminant in either the soil or groundwater.
• e.g. chemical containers, tanks, pipelines, spills, fuels etc
Controlled waters: are defined by the Water Resources Act 1991,
Part III, Section 104, which includes all groundwater, inland waters,
estuaries and coastal water to three nautical miles from the shore.
Basics & Terminology
4th concept of “source, pathway, receptor & a pollutant linkage”
Pathway: is a route, means or mechanism by which a contaminant
comes into contact with, or otherwise affects, a receptor.
e.g. potential pathways, natural and man made, could be:
• ingestion, inhalation, direct contact, dermal contact;
• consumption of home grown vegetables etc.;
• through roots into plants;
• vapour and gas migration;
• migration through the ground, horizontally, preferential pathways;
• migration through the ground, vertically, capillary action, gravity;
• movement with and through groundwater.
Basics & Terminology
4th concept of “source, pathway, receptor & a pollutant linkage”
Receptor: is something that could be adversely affected by a
contaminant, such as; people, living organisms, ecological systems,
controlled waters, atmosphere, structures and utilities.
e.g. potential sensitive receptors could be:
• temporary site or construction workers;
• end users, future residents, home owners; adults & children;
• neighbours;
• shallow perched groundwater;
• deeper groundwater;
• surface waters;
• the ecological system;
• services, (e.g. water supply pipes, phenols penetrate plastic water pipes)
• property (e.g. buildings, land, crops etc)
Basics & Terminology
4th concept of “source, pathway, receptor & a pollutant linkage”
• In UK legislation, the concept of a “source-pathway-receptor” linkage, also known as a
“pollutant linkage” underpins the way in which land affected by contamination is
assessed, and the associated risks are managed.
Basics & Terminology
4th concept of “source, pathway, receptor & a pollutant linkage”
• On any individual site, there may be only a single pollutant linkage or there may be
several. Different pollutant linkages may be related, for example, the same contaminant
may be linked to two or more distinct types of receptor by different pathways, or
different contaminants and/or pathways may affect the same receptor. Not all receptors
will be relevant in every context, and new pollutant linkages may be created by changes
over time. Each pollutant linkage needs to be separately identified, understood and dealt
with if appropriate.
• In UK legislation, the concept of a “source-pathway-receptor” linkage, also known as a
“pollutant linkage” underpins the way in which land affected by contamination is
assessed, and the associated risks are managed.
• For there to be a risk presented to a certain receptor, both a source (referred to as a
'contaminant' in many pieces of guidance) and a pathway must be present.
• Alternatively, for a source to present a risk, a pathway and a receptor must be present.
So the key rule to remember is:
Source => Pathway => Receptor
Missing link = no risk
Basics & Terminology
4th concept of “source, pathway, receptor & a pollutant linkage”
• In UK legislation, the concept of a “source-pathway-receptor” linkage, also known as a
“pollutant linkage” underpins the way in which land affected by contamination is
assessed, and the associated risks are managed.
• On any individual site, there may be only a single pollutant linkage or there may be
several. Different pollutant linkages may be related, for example, the same contaminant
may be linked to two or more distinct types of receptor by different pathways, or
different contaminants and/or pathways may affect the same receptor. Not all receptors
will be relevant in every context, and new pollutant linkages may be created by changes
over time. Each pollutant linkage needs to be separately identified, understood and
dealt with if appropriate.
• For there to be a risk presented to a certain receptor, both a source (referred to as a
'contaminant' in many pieces of guidance) and a pathway must be present.
• Alternatively, for a source to present a risk, a pathway and a receptor must be present.
So the key rule to remember is:
Source => Pathway => Receptor
Missing link = no risk
Basics & Terminology
5th concept is “suitable for use concept”
• UK regulations embrace the concept that land should be “suitable for
use”.
• To ensure that the level of contamination is safe level for the end use.
• Remediation should be to a level commensurate with the end use.
• More sensitive the receptor => More clean-up or control.
• Domestic garden – receptor => More clean-up or control.
• Tesco car park – receptor
=> Less clean-up or control.
• Commercial land use (such as for an office) is viewed as less sensitive
than domestic garden because the time spent in the home tends to be
greater than time spent at the office.
• Typically, residential sites affected by land contamination will require a
greater level of clean-up or remediation than a similar commercial
site.
Basics & Terminology
5th concept is “suitable for use concept”
Terminology, just a brief warning:
“Suitable for use” vs “Fit for purpose”
Suitable for use is a slightly different concept = remediation
appropriate for the proposed end use.
Basics & Terminology
6th concept is “polluter pays principle ”
Once a site has been “determined” [ by the LA under Part IIA ] that
a site presents a risk, the question “who is responsible?” must be
asked.
• This introduces a further concept in UK law, known as the “polluter
pays” principle.
• Put simply, the party who caused or knowingly allowed the pollution,
or contamination, to occur at a site, or allowed a new pollutant
linkage to be formed, is seen as the legally responsible party in UK
law.
• This is sometimes the landowner, but in other cases will be a previous
occupant of the site, or others!!!
Basics & Terminology
7th concept is “step by step or phased approach ”
The investigation of contaminated land [ and also geotechnical investigations
even on uncontaminated sites ] should be a step by step or phased process.
• Questioning, challenging, exploring. understanding, gathering information,
decision making.
• A bit like medical investigation.
• Information gained at each step / phase should be used to determine the
next
• most appropriate step or phase.
– Preliminary
– Supplementary
– Additional
– Detailed
– For final design purposes
– etc
Parties involved
List the parties that may be involved ?
work in a group
Parties involved
Many parties involved, many interested “stakeholders”. Each one likely to have a
different agenda. You need to understand their role / agenda for the best
possible outcome.
• Landowner / Developer / Client
Parties involved
Landowner / Developer / Client
• Is my site contaminated / polluting?
• What are my liabilities?
• Will I be prosecuted, under Part IIA?
• What is the remediation cost, duration etc?
• Is someone else polluting my site?
• Can I sell it?
• How can I mitigate / reduce my remediation / development costs?
Parties involved
Many parties involved, many interested “stakeholders”. Each one likely to have a
different agenda. You need to understand their role / agenda for the best
possible outcome.
• Landowner / Developer / Client
• Consultant/s
Parties involved
Consultants
• Experts in the field, hopefully?
• Bid for the work, in advance.
• Not so easy when it’s a “step by step” process.
• Is it straightforward? Is it time consuming and complex?
• Don’t know what needs to be done till you start looking at it.
• Still, in my opinion, required a multidisciplinary team.
• Depends on the brief, and the purpose [Under Part IIA or the Planning
process] but ideally should be a Geo-Environmental investigation.
• Conflict between being cost effective and efficient vs not missing anything or
being “negligent” and getting sued. Also H&S issues.
• A potentially risky.
Parties involved
Many parties involved, many interested “stakeholders”. Each one likely to have a
different agenda. You need to understand their role / agenda for the best
possible outcome.
• Landowner / Developer / Client
• Consultant/s
• Local Authority; Contaminated Land / Environmental Health Officer
Planners, Building Control, Archaeologists, Ecologists etc
Parties involved
Local Authority; Contaminated Land / Environmental Health Officer Planners,
Building Control, Archaeologists, Ecologists etc
• LA is the primary decision maker.
• Protect human health; but also regeneration, sustainability etc.
• Generally want to encourage remediation, clean up, redevelopment.
• Redevelopment of, blighted, brownfield sites seen as a good thing.
Parties involved
Many parties involved, many interested “stakeholders”. Each one likely to have a
different agenda. You need to understand their role / agenda for the best
possible outcome.
• Landowner / Developer / Client
• Consultant/s
• Local Authority; Contaminated Land / Environmental Health Officer
Planners, Building Control, Archaeologists, Ecologists etc
• Environment Agency
• Other Government Agencies
Parties involved
Environment Agency;
• Generally a consultee to the LA.
• Controlled waters protection.
• However responsible for LA determined Special Sites.
Other Government Bodies:
• Natural England.
• Health Protection Agency.
Parties involved
Many parties involved, many interested “stakeholders”. Each one likely to have a
different agenda. You need to understand their role / agenda for the best
possible outcome.
• Landowner / Developer / Client
• Consultant/s
• Local Authority
Planners, Building Control, Archaeologists, Ecologists etc
• Environment Agency
• Other Government Agencies
• Contractor/s; Principal Contractor & Specialist Remediation Contractor
Parties involved
Contractor/s; Principal Contractor & Specialist Remediation Contractor
• As with Consultants, they bid for work with the associated challenges.
• I suggest, generally Consultants do not, should not, appoint Contractors
directly.
• Client should employ Contractor directly.
• Otherwise Consultant could become liable for Contractor’s work, when it
goes wrong, may not be insured for “fitness for purpose” etc
Parties involved
Many parties involved, many interested “stakeholders”. Each one likely to have a
different agenda. You need to understand their role / agenda for the best
possible outcome.
• Landowner / Developer / Client
• Consultant/s
• Local Authority
Planners, Building Control, Archaeologists, Ecologists etc
• Environment Agency
• Other Government Agencies
• Contractor/s; Principal Contractor & Specialist Remediation Contractor
• Local Community
Parties involved
Local Community
• Concern, worry, lack of understanding, think their kids will all die !!!
• Blight, reduced value of their land, homes.
• Poor communication is often the root of problems.
Parties involved
Many parties involved, many interested “stakeholders”. Each one likely to have a
different agenda. You need to understand their role / agenda for the best
possible outcome.
• Landowner / Developer / Client
• Consultant/s
• Local Authority
Planners, Building Control, Archaeologists, Ecologists etc
• Environment Agency
• Other Government Agencies
• Contractor/s; Principal Contractor & Specialist Remediation Contractor
• Local Community
• Financiers / Funders / Banks
Parties involved
Financiers / Funders / Banks
• What is their interest, agenda???
• Money £££££
• What more can I say???
Parties involved
Many parties involved, many interested “stakeholders”. Each one likely to have a
different agenda. You need to understand their role / agenda for the best
possible outcome.
• Landowner / Developer / Client
• Consultant/s
• Local Authority
Planners, Building Control, Archaeologists, Ecologists etc
• Environment Agency
• Other Government Agencies
• Contractor/s; Principal Contractor & Specialist Remediation Contractor
• Local Community
• Financiers / Funders / Banks
• Utilities
Parties involved
Utilities
• The only utility that I can recall that has an interest in contaminated land are
the Water Companies. Phenol was considered at one time to be able to
permeate through plastic potable drinking water pipes and taint the drinking
water.
• But also consider the corrosive effects of contaminants on services, pipes,
concrete, foundations etc buried in the ground.
Parties involved
Many parties involved, many interested “stakeholders”. Each one likely to have a
different agenda. You need to understand their role / agenda for the best
possible outcome.
• Landowner / Developer / Client
• Consultant/s
• Local Authority
Planners, Building Control, Archaeologists, Ecologists etc
• Environment Agency
• Other Government Agencies
• Contractor/s; Principal Contractor & Specialist Remediation Contractor
• Local Community
• Financiers / Funders / Banks
• Utilities
• SOLICITORS