Environment Agency Remediation position Statements (Version 3, issued 17/11/2010)

Remediation position statements
Operational instruction 226_06
Issued 17/11/2010
This document is for staff at level 2 capability of the Permitting and
Compliance: Issues and maintains permits capability in the GWCL and
National Permitting Service technical development frameworks
What’s this
document
about?
This document sets out our regulatory position on the
different technologies that can be used to remediate
contaminated soil and water.
It provides guidance to staff who deal with land and water
remediation. It is particularly relevant to permitting officers
who issue mobile plant permits 1 and assess mobile plant
permit deployment applications.
It also informs industry and other interested parties on how
we apply risk-based regulation to the remediation of land
and water contamination problems.
Who does this
apply to?
All staff involved in permitting and compliance activities
associated with the remediation of land contamination
and/or water using a treatment technology requiring either a
bespoke or standard rules mobile plant permit.
Document
details
Related
documents
Feedback
This includes:

1
National Permitting Service – permitting officers;
Groundwater and Contaminated Land (GWCL) teams;
Environment Management teams;
Area Waste specialists.
Contact for
queries
Matthew
Whitehead
These were called mobile treatment licences under the Waste Management Licensing Regulations 1994
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Contents
Doc No 226_06
Remediation Position Statements
3
General Permit Information
4
Enforcement Position Statements
8
Remediation Position Statement 1
9
Remediation Position Statement 2
10
Remediation Position Statement 3
11
Remediation Position Statement 3A
13
Remediation Position Statement 3A
14
Remediation Position Statement 4
15
Remediation Position Statement 5
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Remediation Position Statement 5
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Remediation Position Statement 6
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Remediation Position Statement 6
19
Remediation Position Statement 7
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Remediation Position Statement 8
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Remediation Position Statement 8
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Remediation Position Statement 9
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Remediation Position Statement 10
25
Remediation Position Statement 11
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Remediation Position Statement 12
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Remediation Position Statement 12
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Remediation Position Statement 13
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Remediation Position Statement 13
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Remediation Position Statement 14
33
Remediation Position Statement 15
35
Related documents
36
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Remediation Position Statements
Listed
remediation
processes
The joint Environment Agency/DEFRA publication CLR11 (Contaminated
land report 11 - Model procedures for the management of land
contamination) lists fifteen types of land contamination remediation
processes. Each of these has been summarised in this document in the form
of Remediation Position Statements:

What do the
remediation
position
statements
tell us?
Civil engineering methods
1. Cover systems
2. Containment barriers
3. Excavation and disposal
3A. Removal of groundwater for disposal/ recovery
Biological methods
4. Monitored natural attenuation
5. Ex-situ bioremediation
6. In-situ bioremediation
7. Bioventing
Chemical methods
8. Soil flushing
9. Solvent extraction
10. Transformation by chemical treatment
Physical methods
11. Soil vapour extraction
12. Soil washing
13. Permeable reactive barriers
Solidification and stabilisation methods
14. Solidification and stabilisation
Thermal methods
15. Thermal desorption
They provide:
a brief description of the technology;

an overview of how the treatment processes apply to different types of
contaminated materials and contaminant groups. The applicability of
each treatment process has been compiled in accordance with the joint
Environment Agency/DEFRA publication CLR11. The information
contained within the statements is indicative only and not to be taken as
absolute. There may be a wide range of process and site-specific
variations to all of the technologies, which have not been detailed;

a summary of the permitting implications associated with each
technology;

identification of any applicable exemptions from the Environmental
Permitting Regulations 2010;

identification of any particular enforcement positions that the Environment
Agency may take/ apply dependant upon site specific circumstances.
The remediation position statements set out the regulatory requirements
referred to in the Environment Agency’s Guidance for the Enforcement and
Prosecution Policy.
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General Permit Information
Types of
Permit
The treatment of contaminated soil and/ or contaminated waters requires an
environmental permit. These permits can be either ‘site based permits’ or
‘mobile plant permits’.
A mobile plant permit is used to regulate a mobile plant activity which
involves treatment either in-situ or ex-situ. The permit sets out the type and
extent of activities that can be carried out. The mobile plant permit is not
designed to ensure the process will meet any remediation objectives
specified under Planning, Part 2A or other legislative controls. These issues
must be considered by the relevant regulatory body or by the
developer/consultant within their overall site remediation plan. The purpose
of the permit is to control the emissions from the treatment process to avoid
pollution of the environment or harm to human health.
A site based permit has to be used where a mobile plant permit is not
applicable. The environmental permit can be either a standard rules permit or
a bespoke one depending upon the type of treatment and site location. New
standard rules permits for land remediation and waste treatment were
introduced on 6 April 2010. They cover the majority of remediation activities
that are no longer exempt. Standard rules permits that apply to land
remediation activities can be found on our standard permits for waste
operations webpage. A bespoke permit will be required for operations that do
not fit the standard rules.
Mobile plant
permit deployment
application
Operators who want to treat contaminated soil and/ or contaminated waters
using their mobile plant permit at a particular site must submit a site-specific
deployment application (the deployment form and supporting information).
The deployment application details site specific information and potential
impacts arising from the proposed use of the mobile plant. The operator must
demonstrate that the activity will not cause pollution of the environment,
harm to human health or serious detriment to the amenities of the locality.
We must agree the deployment application in writing before treatment
operations can begin at the site.
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CL:AIRE
Definition of
Waste:
Development
Industry Code
of Practice
(CoP)
This is a voluntary Code of Practice (CoP), which provides a framework for
determining whether or not excavated material used in land development is
waste. The CoP has been produced by industry and is supported by the
Environment Agency. Our Definition of Waste Position Statement (PS006)
explains how we will take account of the CoP in regulating development
activities.
Excavated material generated by the development of land may be waste and
subject to waste regulatory controls, which ensure that waste does not harm
human health or the environment.
Whether or not a substance or material is waste depends on whether the
holder of a substance or material is discarding it, or intends to or is required
to discard it. This must be considered in the light of all the specific
circumstances of each case.
The CoP sets out good practice for the development industry to use when
assessing:
What the CoP
applies to
What the CoP
does not
apply to

whether materials can be classified as waste or not; and

determining when treated waste can cease to be waste for a particular
use.
The CoP applies to excavated material, both uncontaminated and
contaminated, from man made and natural sources:

for re-use on the site from which it has been excavated, either without
treatment or after on site treatment, in the development of that land

for re-use in the development of land other than the site from which the
material has been excavated, following treatment 2 at an authorised
treatment hub 3 within a defined cluster agreed with us, and used in the
development of land at a site within the cluster.
The CoP does not currently apply to materials that go directly off site for use
at another site (that is, without being treated at a hub site) or wastes that go
to and from fixed soil treatment facilities unless it operates as a hub within a
defined cluster project.
These materials are waste and the activities remain subject to waste
regulatory control.
2
When using the CoP the only acceptable treatment methods are ex-situ treatments either on the site of production
that is the donor site or off site at the hub site.
3
A treatment facility regulated under Environmental Permitting Regulations 2010 via either a mobile plant permit
or a site based permit.
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Recovery of
waste
contaminated
soil/
groundwater
The treatment of soil/ groundwater for the purpose of reclamation, restoration
or improvement of land is a recovery operation whereby the treated material
replaces other [non waste] materials which would have had to be used for
that purpose. This conserves natural resources.
Any waste (whether inert, non-hazardous or hazardous) is capable of being
used in a recovery operation. Note: the waste must always be suitable for the
purpose it is intended. It must form part of a land remediation scheme and
meet the required remedial objectives.
If excavated materials are recovered via a treatment operation then their reuse at a site may be dealt with by the Development Industry CoP.
Disposal of
waste
contaminated
soil/
groundwater
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All waste activities, other than temporary storage at the place of production,
are classified as either disposal or recovery operations. So where soil/
groundwater is not being recovered it is deemed to be part of a disposal
operation. The disposal of contaminated material by landfill or incineration
requires a site based environmental permit.
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Exemptions
The exemptions system changed on 6 April 2010. All new waste operations
must now be registered as exempt under the new system. If they do not
meet the new exemption definitions then an environmental permit must be
applied for.
Information about the new system of exemptions and transitional provisions
for existing activities is available on our waste exemptions webpage.
Five exemptions applied to land remediation activities under the old system.
These were:

Exemption 7. Spreading of waste on land for benefit to agriculture or
ecological improvement.

Exemption 9. The spreading of waste on any land in connection with the
reclamation and improvement of that land.

Exemption 13. The manufacture and treatment of waste soils.

Exemption 19. Use of waste for ‘relevant works’ (‘relevant works’ includes
construction and maintenance of certain facilities).

Exemption 41. The temporary storage of waste at site of production
The two new exemptions most applicable to land remediation activities are:
U1. Use of waste in construction.
T5. Screening and blending of waste.
There are limits to the amount of material that can be used or treated under
the new exemptions. All activities that were formerly regarded as exemptions
but do not meet the new requirements must obtain an environmental permit.
Operators must apply for a permit for new operations or for existing activities
transferring in to the new system under the transitional timetable. See
Making the steps to permitting.
The non- Waste Framework Directive exemption for temporary storage of
waste at the place of production can be used to temporarily store any waste
on the site pending its collection.
For an activity to be considered exempt the waste must be stored or
recovered without endangering human health and without using processes or
methods which could harm the environment, and in particular without:

risk to water, air, soil, plants or animals;

causing nuisance through noise or odours;
adversely affecting the countryside or places of special interest.
If the concentrations of substances in the waste material lead it to be defined
as hazardous waste then it cannot benefit from exemptions U1 or T5. Where
the waste is not hazardous waste but contains dangerous substances, a risk
assessment must be carried out to demonstrate that the activity does not
pose a threat.
Exempt
groundwater
activities
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There is an exemption under schedule 3, Part 3 of the Environmental
Permitting Regulations 2010 for the discharge of small quantities of
substances for scientific purposes as part of a specified groundwater
remediation scheme. This exemption applies to remediation schemes where
substances are added to the ground/ groundwater to enhance the rate of
remediation of the groundwater. See our Module on small discharges to
groundwater for more information on this exemption.
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Enforcement Position Statements
Pilot trials/
small scale
remediation
schemes
An environmental permit is required for all remedial projects which involve
the treatment of waste. However, applying our Enforcement and
Prosecution Policy and our commitment to proportionate regulation we will
not enforce the requirement for such a permit for use in small scale
remediation schemes or site specific pilot trials of existing techniques
provided that:

the total quantity of contaminated materials being treated doesn’t exceed
1000 cubic metres 4 ;

the following information is supplied to the Environment Agency Area
office at least five working days before the project begins:
site address and contact details of any landowner, developer or
contractor involved in the remediation project;
expected duration of the activity;
details of the specific measures to be employed so as to prevent
pollution of the environment, harm to health or serious detriment to
amenities of the locality; and

we have no subsequent objection to the treatment operation in question
for example, on the grounds we consider the proposed treatment
operation to pose an unacceptable risk to the environment.
Note: We are reviewing the way this enforcement position is applied to small
scale remediation schemes to make sure it is being interpreted properly. The
conditions for complying with this position may be subject to change in the
future. However, we will not retract previously agreed enforcement positions
or licensing/permitting positions for specific sites once they have been
applied.
Regulating
trials of new/
novel waste
management
activities
The Environment Agency has a separate universal enforcement position
(PS004) relating to the trial of new/ novel techniques that may apply to land
remediation activities.
Using the
enforcement
positions
The enforcement positions for pilot trials and small scale remediation and for
trials of new techniques (PS004) relate to treatment, both in-situ and ex-situ.
Note: enforcement position statement PS004 covers trials that may be
relevant to all of the remediation position statements set out in this
document.
Note: An environmental permit is still required for:

re-use of soils treated ex-situ unless a declaration is made in full
accordance with the Development Industry CoP

discharges of treated effluents to groundwater unless the discharge is
excluded from the Environmental Permitting Regulations 2010 under
Schedule 22 (3)(3).
Additional enforcement positions specific to individual remediation
techniques are contained within the remediation position statement
templates.
4
1000m3 is defined for in-situ treatment as the pre-excavated volume of the impacted site to be remediated. For
example 10m x 10m x 10m. For ex-situ treatment it refers to the volume of material excavated or pumped.
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Remediation Position Statement 1
Technology title
Cover systems
Similar techniques
Horizontal barriers, liners
Technology description
Cover systems involve the placement of natural and/ or synthetic materials over the
contaminated ground. They are designed to isolate the contaminated ground from direct
contact by receptors and reduce the transfer of gases and the infiltration of water thereby
reducing or eliminating contaminant migration.
Typical contaminant groups treated
Organic contaminants
Inorganic contaminants
VOCs
9
Heavy metals
9
Halogenated hydrocarbons
9
Inorganics (NO3, SO4)
9
Non-halogenated hydrocarbons
9
Asbestos
9
PAHs
9
Miscellaneous
Dioxins/ furans
9
Corrosives
9
PCBs
9
Cyanides
9
Pesticides/ herbicides
9
Explosives
9
Regulatory position
The placement of a cover system using “clean” material is not effecting the treatment of waste.
Therefore, it does not need to be regulated under an environmental permit and no enforcement
position statements are applicable to this type of remediation.
If the cover system uses ‘waste materials’ in its construction then exemptions U1 and T5 may
apply. If the installation of the proposed cover system does not meet the criteria for registration
of these exemptions the activity may be regulated through a site based permit.
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Remediation Position Statement 2
Technology title
Containment barriers
Similar techniques
Vertical barriers, in-ground barriers, cut-off walls
Technology description
Barriers are used to prevent the lateral migration of contaminants. The techniques available for
the formation of barriers include:

displacement techniques such as sheet pilling, to introduce the barrier into the ground but
where the ground is left relatively undisturbed;
excavation of the ground to construct a trench or similar structure in which the barrier is
formed or installed;
injection of materials into the ground which react/ interact with the soil to change its
properties and create a barrier in-situ but with minimal disturbance of the ground.
Typical contaminant groups treated
Inorganic contaminants
Organic contaminants
VOCs
9
Heavy metals
9
Halogenated hydrocarbons
9
Inorganics (NO3, SO4)
9
Non-halogenated hydrocarbons
9
Asbestos
9
PAHs
9
Miscellaneous
Dioxins/ furans
9
Corrosives
9
PCBs
9
Cyanides
9
Pesticides/ herbicides
9
Explosives
9
Regulatory position
Where the containment barrier is being installed around or through waste and it does not
involve the use/ re-deposit of those materials then it does not need an environmental permit.
Where the construction of a barrier does involve the removal and subsequent re-deposition of
materials, this is normally considered a disposal operation unless fully justified otherwise via
use of the Development Industry CoP. If the deposit is regarded as disposal it must be
regulated through an environmental permit.
Where the construction of the barrier itself involves the recovery/ use of in-situ waste, then the
installation operation should be regulated through a site based or mobile plant permit as
appropriate. If the in-situ recovery operation results in the permanent storage of waste, we will
apply a risk-based decision on whether to require a site based permit for the keeping of this
waste. We will take account of the following aspects when reaching this decision:

the use of treated material is suitable for the purposes of reclamation, restoration or
improvement at that site, and;

off site disposal to landfill
on site disposal to landfill
off site treatment to soil recovery centre
on site treatment for recovery or disposal
on site re-use without treatment under an exemption from the Environmental Permitting
Regulations 2010.
Typical contaminant groups treated
Organic contaminants
Inorganic contaminants
VOCs
9
Heavy metals
9
Halogenated hydrocarbons
9
Inorganics (NO3, SO4)
9
Non-halogenated hydrocarbons
9
Asbestos
9
PAHs
9
Miscellaneous
Dioxins/ furans
9
Corrosives
9
PCBs
9
Cyanides
9
Pesticides/ herbicides
9
Explosives
9
Regulatory position
Excavation
Excavation of contaminated material, substances or products, for the purpose of transportation
is not considered to be a recovery/ disposal activity in its own right; and so does not need an
environmental permit. However, if the overall site remediation scheme is permitted under the
Environmental Permitting Regulations 2010 and excavation is an associated activity then it may
be included and controlled via that permit.
Reducing the amount of material to be excavated
Appropriate levels of site investigation to characterise and delineate contamination on site must
be undertaken to reduce the need for movement or recovery/ disposal of contaminated
materials.
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Remediation Position Statement 3
Classification of materials
It is the responsibility of the operator/ contractor/ developer to establish whether the excavated
material on site is a waste or not. The Development Industry CoP sets out good practice to use
when assessing if materials are classified as waste and determining when treated waste can
cease to be waste for a particular use. If the excavation process involves distinct physical
segregation and sorting activities, which are regarded as treatment, then a site based/ mobile
plant permit may be required.
If the excavated material is directive waste it needs to be classified in accordance with the
European Waste Catalogue to determine whether it is also hazardous waste.
Duty of care
The waste producer or holder of waste must take all reasonable steps to ensure there is no
unauthorised treatment, storage, recovery or disposal of the waste. They must ensure that it
does not escape from their control and is only transferred to an authorised person together with
a written description of the waste. The duty of care requires that:

a full written, accurate description of the waste is provided to the next holder;
where the waste is destined for landfill, holders must establish whether or not it is
hazardous;
the description must include the relevant European Waste Catalogue code(s).
Recovery operations
The recovery of excavated materials must be regulated through an appropriately authorised
waste facility. The treatment of waste soils and groundwater may be regulated through a site
based/ mobile plant permit in accordance with the relevant remediation position statements.
The conditioning of soil (which is not contaminated or does not containing dangerous
substances), on the site where it is to be used to improve its geotechnical properties by the
addition of material which is not itself a waste, is not effecting the treatment of waste. Therefore
there are no environmental permitting implications. So no enforcement position statements are
applicable to this type of activity.
Storage of waste
The temporary storage of excavated waste materials, for the purposes of reclamation,
restoration or improvement of land, is subject to control via either a mobile plant permit, a site
based permit, an exemption from the Environmental Permitting Regulations 2010 or as part of
the pilot trials/ small scale remediation schemes enforcement position statement.
The temporary storage of waste prior to collection for disposal or recovery off site may be
carried out under the non-Waste Framework Directive exemption for temporary storage at the
place of production pending its collection.
Use of treated materials
Waste materials that have been subject to a successful treatment/recovery operation (that is
treated to an agreed standard/ specification) may be re-used in accordance with the
Development Industry CoP.
If materials have not been successfully recovered then they will remain waste. The two
exemptions that could be relevant to the subsequent use of that waste, are U1 and T5. Where
an exemption doesn’t apply then the only other available option is a site based permit.
Disposal operations
The disposal by landfill of excavated materials is regulated through a site based permit. The
excavated material may be disposed of to an inert, non-hazardous or hazardous waste landfill,
whichever is appropriate, and will have to comply with the relevant Waste Acceptance Criteria.
The Environmental Permitting Regulations 2010 require landfill operators to ensure that all
waste accepted at the site has been pre-treated unless it is inert waste, for which treatment is
not technically feasible, or it is a waste other than inert waste and treatment would not reduce
its quantity or the hazards which it poses to human health or the environment.
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Remediation Position Statement 3A
Removal of groundwater for disposal/ recovery
Technology title
Similar techniques
Technology description
Groundwater is removed for treatment above ground (pump and treat) using treatment
methods such as:
chemical treatment;
biological treatment;
air stripping;
filtration;
carbon adsorption.
Typical waste streams include:

process effluents resulting from the treatment;
sludges, free product, filters.
Typical contaminant groups treated
Organic Contaminants
Inorganic contaminants
VOCs
9
Heavy Metals
9
Halogenated hydrocarbons
9
Inorganics (NO3, SO4)
9
Non-halogenated hydrocarbons
9
Asbestos
8
PAHs
9
Miscellaneous
Dioxins/ furans
9
Corrosives
9
PCBs
9
Cyanides
9
Pesticides/ herbicides
9
Explosives
9
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Remediation Position Statement 3A
Regulatory position
Removing or pumping contaminated groundwater for the purpose of remediating land or
controlled waters is not effecting the treatment of waste and so does not need an
environmental permit.
Where the contaminated groundwater is subsequently remediated ex-situ it needs to be
regulated through a mobile plant permit or a site based permit. The process can be considered
under the pilot trials/ small scale remediation schemes enforcement position statement.
The removal of more than or equal to 20 m3/day of water, for the purpose of remedial action,
requires an abstraction licence under the Water Resources Act 1991.
The discharge of treated waters can occur in a number of ways such as:

discharge to foul sewer; this would be subject to consent from the appropriate utility
provider;

discharge to surface water; this would be a water discharge activity under the
Environmental Permitting Regulations 2010 and would require an environmental permit;

discharge to ground or groundwater; this would be a groundwater activity under the
Environmental Permitting Regulations 2010 and would require an environmental permit.
The regulations require that the input of hazardous substances to groundwater is prevented
and the input of non-hazardous pollutants is limited so as to avoid pollution. If after
treatment the discharge is still likely to contain hazardous substances, we may consider the
granting of a permit under Schedule 22 paragraph 8(b) of the Environmental Permitting
Regulations 2010 in circumstances where:
1. the re-injection is solely part of a scheme which is for the purpose of achieving defined
objectives for the clean-up and improvement of ground and/ or groundwater quality;
2. the re-injected water is returned to the same stratum and hydraulic system from which
the water was originally abstracted;
3. the re-injection is within the defined area of contaminated water under remediation;
4. the re-injection will not cause the movement of the contaminated water that is the
subject of remediation such that hazardous substances enter areas of other
groundwater or that other groundwater is polluted by non-hazardous pollutants;
5. the discharge will be subject to the necessary investigations and risk assessment to
ensure that (4) above will be complied with;
6. it can be demonstrated that, in conjunction with other aspects of the remediation
scheme (for example bioremediation), the proposed level (or lack) of treatment of the
abstracted water prior to re-injection is consistent with achieving the overall defined
remedial objectives;
7. the details of the overall scheme of remediation along with the results of investigation
and risk assessment have been provided to us prior to commencement of any
discharge;
8. the re-injection will be subject to sufficient monitoring to ensure compliance with the
requirements of the Environmental Permitting Regulations 2010.
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Remediation Position Statement 4
Technology title
Monitored natural attenuation
Similar techniques
Technology description
Natural attenuation is the effect of naturally occurring physical, chemical, and biological
processes or any combination of these processes to reduce the load, concentration, flux or
toxicity of polluting substances in groundwater.
For natural attenuation to be an effective remedial treatment action, the rate at which these
processes occur, must be sufficient to prevent polluting substances impacting on identified
receptors and to minimize expansion of contaminant plumes into unpolluted groundwater.
Dilution within a receptor, such as a river or borehole, is not natural attenuation. Natural
attenuation therefore describes the effect of natural processes. Monitored natural attenuation is
used to refer to the remedial technique, which by definition is a monitored activity. Monitored
natural attenuation requires sufficient evidence to demonstrate that the attenuation processes
are occurring and will continue to occur so as to achieve the required remedial objectives within
an agreed time frame and that the wider environment is protected.
Typical contaminant groups treated
Inorganic contaminants
Organic contaminants
VOCs
9
Heavy Metals
9
Halogenated hydrocarbons
9
Inorganics (NO3, SO4)
9
Non-halogenated hydrocarbons
9
Asbestos
8
PAHs
9
Miscellaneous
Dioxins/ furans
8
Corrosives
9
PCBs
8
Cyanides
8
Pesticides/ herbicides
9
Explosives
9
Regulatory position
Although natural attenuation is effecting the treatment of waste there is no human intervention
other than monitoring and so it does not need an environmental permit and no enforcement
position statements can be applied.
The design, installation and monitoring regime must be undertaken in line with good practice as
outlined in the relevant Environment Agency science reports.
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Remediation Position Statement 5
Technology title
Ex-situ bioremediation
Similar techniques
Biopiles, windrow turning and landfarming, bioreactors
Technology description
Bioremediation is a process that exploits the ability of natural soil microbial populations (for
example bacteria and fungi) to biodegrade or biotransform toxic environmental organic and
inorganic pollutants to less toxic or innocuous products (for example CO2 and H2O).
Bioremediation processes may be operated under aerobic (with oxygen) and/ or anaerobic (no
oxygen) conditions to restore contaminated soils to a state suitable for use.
A bioremediation process operated as a soil treatment bed is a process in which excavated soil
is placed in an above ground treatment area and stimulated to enhance the biodegradation of
contaminants present. Aeration of the soil and the addition of microbes and nutrients are
effective measures to enhance this process. Soil treatment beds may be either temporary
installation on site or as fixed installations (on site or off site) to which batches of soil are
transported for treatment. Pre-treatment may be necessary to remove objects and to produce a
feedstock of the correct physical form and consistency for biotreatment.
Typical waste streams generated during treatment include:

volatile vapour emissions;
vapour and liquid residual after treatment of waste streams (for example spent GAC
filters);
generation of contaminated soil leachates and process effluents;
generation of toxic intermediates in soils;
solid rejects.
Typical contaminant groups treated
Inorganic contaminants
Organic contaminants
VOCs
9
Heavy Metals
8
Halogenated volatiles
8
Inorganics (NO3, SO4)
8
Non-halogenated semi-volatiles
9
Asbestos
8
PAHs
9
Miscellaneous
Dioxins/ furans
8
Corrosives
8
PCBs
8
Cyanides
8
Pesticides/ herbicides
9
Explosives
9
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Remediation Position Statement 5
Regulatory position
These types of bioremediation processes will generally be waste recovery operations and so
need to be regulated via an environmental permit (mobile plant or site based). No
environmental permitting exemptions apply. The process can be considered under the pilot
trials/ small scale remediation schemes enforcement position statement.
Storage of excavated waste
The temporary storage of excavated waste materials, for the purposes of reclamation,
restoration or improvement of land, is subject to control via either a mobile plant permit, a site
based permit, an exemption from the Environmental Permitting Regulations 2010 or as part of
the pilot trials/ small scale remediation schemes enforcement position statement.
The temporary storage of waste prior to collection for disposal or recovery off site may be
carried out under the non- Waste Framework Directive exemption for temporary storage at the
place of production pending its collection.
Use of treated materials
Waste materials that have been subject to a successful treatment/ recovery operation (that is
treated to an agreed standard/ specification) may be re-used in accordance with the
Development Industry CoP.
If materials have not been successfully recovered then they will remain waste. The two
exemptions that could be relevant to the subsequent use of that waste are U1 and T5. Where
an exemption doesn’t apply then the only other available option is a site based permit.
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Remediation Position Statement 6
Technology title
In-situ bioremediation
Similar techniques
Biosparging, biorestoration, biostimulation, bioaugmentation
Technology description
Bioremediation is a process that exploits the ability of natural soil microbial populations (for
example Bacteria and fungi) to biodegrade or biotransform toxic environmental organic and
inorganic pollutants to less toxic or innocuous products (such as, CO2 and H2O).
Bioremediation processes may be operated in-situ or ex-situ under aerobic (with oxygen)
and/or anaerobic conditions (no oxygen) to restore contaminated soils to a state suitable for
use.
In -situ bioremediation is the enhancement or stimulation of biological processes to degrade,
transform or remove contaminants present in soils and groundwater. This process involves
stimulating the biodegradative activities of soil bacteria by adding nutrients such as nitrogen
and phosphorus as well as oxygen and other electron acceptors to the soil to enhance its
microbial activity. In some cases, microbes are added to the soil to help the degradation
processes. This process is known as Bioaugmentation. In-situ bioremediation processes can
be applied to surface or near-surface soils or at greater depths in the unsaturated zone.
Surface treatment - Application of in-situ bioremediation to surface or near-surface soils may
require amendments to be made using inorganic nutrients (nitrogen, phosphorus, and so on)
and/ or organic materials (manure, sewage sludge). In some situations, more concentrated
nutrient solutions or “specialists additives” (for example surfactants, chelating agents,
enzymes) may be added.
At-depth treatment - In-situ bioremediation techniques to treat contaminated soil at a depth
normally involve the use of water recirculation systems. Aerated water containing nutrient
amendments are percolated through the contaminated zone whilst water containing
degradation products and residual contaminants are simultaneously extracted for further
treatment above ground (see Remediation Position Statement 3).
Typical waste streams generated during treatment include:

volatile vapour emissions;

generation of process effluents;

generation of toxic intermediates in soils.
Typical contaminant groups treated
Organic contaminants
Inorganic contaminants
VOCs
9
Heavy metals
8
Halogenated volatiles
9
Inorganics (NO3, SO4)
8
Non-halogenated semi-volatiles
9
Asbestos
8
PAHs
9
Miscellaneous
Dioxins/ furans
8
Corrosives
8
PCBs
8
Cyanides
8
Pesticides/ herbicides
9
Explosives
8
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Remediation Position Statement 6
Regulatory position
These types of bioremediation processes will generally be waste recovery operations and so
need to be regulated via an environmental permit (mobile plant or site based). No
environmental permitting exemptions apply. The process can be considered under the pilot
trials/ small scale remediation schemes enforcement position statement.
If the in-situ recovery operation results in the permanent storage of waste, we will apply a riskbased decision on whether to require a site based permit for the keeping of this waste. We will
take account of the following aspects when reaching this decision:

the use of treated material is suitable for the purposes of reclamation, restoration or
improvement at that site, and;

the use of treated material is suitable for the purposes of reclamation, restoration or
improvement at that site; and

process effluents resulting from the addition of reagents or following recovery from the
ground;
concentrated sludge, filters, and free product from the effluent treatment plant.
Typical contaminant groups treated
Organic contaminants
Inorganic contaminants
VOCs
9
Heavy metals
9
Halogenated volatiles
9
Inorganics (NO3, SO4)
8
Non-halogenated semi-volatiles
9
Asbestos
8
PAHs
9
Miscellaneous
Dioxins/ furans
8
Corrosives
8
PCBs
8
Cyanides
8
Pesticides/ herbicides
8
Explosives
8
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Remediation Position Statement 8
Regulatory position
These types of processes will generally be waste recovery operations and so need to be
regulated via an environmental permit (mobile plant or site based). No environmental
permitting exemptions apply. The process can be considered under the pilot trials/ small scale
remediation schemes enforcement position statement.
If the in-situ recovery operation results in the permanent storage of waste, we will apply a riskbased decision on whether to require a site based permit for the keeping of this waste. We will
take account of the following aspects when reaching this decision:

the use of treated material is suitable for the purposes of reclamation, restoration or
improvement at that site, and;

the treated material has been tested both physically and chemically to demonstrate that it
will not cause pollution of the environment, harm to human health or serious detriment to
amenities within the overall remediation scheme and that this is consistent with the need
for the regulator to exercise its relevant functions as required by paragraph 4(a) Schedule 9
of the Environmental Permitting Regulations 2010.
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Remediation Position Statement 9
Technology title
Solvent extraction
Similar techniques
Technology description
Solvent extraction is normally an ex-situ based system used for the removal of contaminants
from soil. Contaminated soils are mixed with a solvent in a reaction vessel in order to transfer
the soil-bound contaminants into the solvent, which is then separated from the soil for further
treatment. Typical solvents are organic chemicals (including many common industrial reagents)
and aqueous solutions.
Once separated from the soil the used solvent is normally treated to recover the solvent and
concentrate the contaminants in a sludge or free phase extract in a separate chamber. Process
streams generated during this treatment include concentrated contaminants either as free
phase, concentrated in the solvent, or as a sludge, as well as recycled solvent and liquid
effluent.
Typical contaminant groups treated
Organic contaminants
Inorganic contaminants
VOCs
9
Heavy metals
8
Halogenated hydrocarbons
9
Inorganics (NO3, SO4)
8
Non-halogenated hydrocarbons
9
Asbestos
8
PAHs
9
Miscellaneous
Dioxins/ furans
9
Corrosives
8
PCBs
9
Cyanides
8
Pesticides/ herbicides
9
Explosives
9
Regulatory position
These types of processes will generally be waste recovery operations and so need to be
regulated via an environmental permit (mobile plant or site based). No environmental permitting
exemptions apply. The process can be considered under the pilot trials/ small scale
remediation projects enforcement position statement.
Storage of treated waste
The temporary storage of excavated waste materials, for the purposes of reclamation,
restoration or improvement of land, is subject to control via either a mobile plant permit, a site
based permit, a permit exemption or as part of the pilot trials/ small scale remediation schemes
enforcement position statement.
The temporary storage of waste prior to collection for disposal or recovery off site may be
carried out under the non- Waste Framework Directive exemption for temporary storage at the
place of production pending its collection.
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Remediation Position Statement 9
Use of treated materials
Waste materials that have been subject to a successful treatment/ recovery operation (that is
treated to an agreed standard/ specification) may be re-used in accordance with the
Development Industry CoP.
If materials have not been successfully recovered then they will remain waste. The two
exemptions that could be relevant to the subsequent use of that waste are U1 and T5. Where
an exemption doesn’t apply then the only other available option is an environmental permit.
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Remediation Position Statement 10
Technology title
Transformation by chemical treatment
Similar techniques
Redox reactions, reduction, oxidation, hydrolysis, neutralisation,
dehalogenation
Technology description
Chemical treatment may be applied directly to soils or employed as part of a broader remedial
strategy (for example after thermal desorption, soil washing or soil flushing processes) to
destroy the contaminants, reduce their toxicity, increase or decrease solubility, or to increase
their susceptibility to other forms of treatment (for example biological). Principal chemical
treatment processes include: oxidation, reduction, hydrolysis, dehalogenation and precipitation
which may be operated either in-situ or ex-situ.
Typical waste streams generated during both in-situ and ex-situ chemical treatments include:

emissions of volatile compounds during the pretreatment stages;
vapour and liquid residuals following waste stream treatment (such as, spent GAC filters);
generation of process effluents;
generation of toxic intermediates in soils.
Typical contaminant groups treated
Organic contaminants
Inorganic contaminants
VOCs
9
Heavy metals
9
Halogenated hydrocarbons
9
Inorganics (NO3, SO4)
9
Non-halogenated hydrocarbons
9
Asbestos
8
PAHs
9
Miscellaneous
Dioxins/ furans
9
Corrosives
9
PCBs
9
Cyanides
9
Pesticides/ herbicides
9
Explosives
9
Regulatory position
These types of processes will generally be waste recovery operations and so need to be
regulated via an environmental permit (mobile plant or site based). No environmental permitting
exemptions apply. The process can be considered under the pilot trials/ small scale
remediation schemes enforcement position statement.
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Remediation Position Statement 10
Storage of treated waste
The temporary storage of excavated waste materials, for the purposes of reclamation,
restoration or improvement of land, is subject to control via either a mobile plant permit, a site
based permit, a permit exemption or as part of the pilot trials/ small scale remediation schemes
enforcement position statement.
The temporary storage of waste prior to collection for disposal or recovery off site may be
carried out under the non- Waste Framework Directive exemption for temporary storage at the
place of production pending its collection.
If the recovery operation is in-situ and this results in the permanent storage of waste, we will
apply a risk-based decision on whether to require an application for a site based permit to be
made for the keeping of this waste where it was treated. We will take account of the following
aspects when reaching this decision:

the use of treated material is suitable for the purposes of reclamation, restoration or
improvement at that site, and;

vapour and liquid residuals following waste stream treatment (such as, spent GAC
filters);
free product if system is adapted to remove free product.
The application of soil vapour extraction processes can be adapted in a number of ways
depending upon the site conditions and the contamination present. Volatilisation of
contaminants may be improved by injecting steam into soil and/ or groundwater. The process
of removing a combination of free product, volatile organic compounds and contaminated
groundwater is known as dual phase or multi-phase extraction.
Typical contaminant groups treated
Organic contaminants
Inorganic contaminants
VOCs
9
Heavy metals
8
Halogenated volatiles
9
Inorganics (NO3, SO4)
8
Non-halogenated semi-volatiles
9
Asbestos
8
PAHs
8
miscellaneous
Dioxins/ furans
8
Corrosives
8
PCBs
8
Cyanides
8
Pesticides/ herbicides
8
Explosives
8
Regulatory position
These types of processes will generally be waste recovery operations and so need to be
regulated via an environmental permit (mobile plant or site based). No environmental
permitting exemptions apply. The process can be considered under the pilot trials/ small scale
remediation schemes enforcement position statement.
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Remediation Position Statement 11
If the in-situ recovery operation results in the permanent storage of waste, we will apply a riskbased decision on whether to require a site based permit for the keeping of this waste. We
will take account of the following aspects when reaching this decision:

the use of treated material is suitable for the purposes of reclamation, restoration or
improvement at that site, and;

a recovered soil fraction with lower contamination levels than the bulk material.
a concentrated soil fraction containing higher contamination levels than the bulk
material.
a liquid effluent.
Typical contaminant groups treated
Organic contaminants
Inorganic contaminants
VOCs
8
Heavy metals
9
Halogenated hydrocarbons
9
Inorganics (NO3, SO4)
9
Non-halogenated hydrocarbons
9
Asbestos
8
PAHs
9
Miscellaneous
Dioxins/ furans
8
Corrosives
8
PCBs
9
Cyanides
9
Pesticides/ herbicides
9
Explosives
8
Regulatory position
This type of process will generally be a waste recovery operation and so needs to be
regulated via an environmental permit (mobile plant or site based). No environmental
permitting exemptions apply. The process can be considered under the pilot trials/ small scale
remediation schemes enforcement position statement.
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Remediation Position Statement 12
Storage of treated waste
The temporary storage of excavated waste materials, for the purposes of reclamation,
restoration or improvement of land, is subject to control via either a mobile plant permit, a site
based permit, a permit exemption or as part of the pilot trials/ small scale remediation
schemes enforcement position statement.
The temporary storage of waste prior to collection for disposal or recovery off site may be
carried out under the non- Waste Framework Directive exemption for temporary storage at
the place of production pending its collection.
Use of treated material
Waste materials that have been subject to a successful treatment/ recovery operation (that is
treated to an agreed standard/ specification) may be re-used in accordance with the
Development Industry CoP.
If materials have not been successfully recovered then they will remain waste. The two
exemptions that could be relevant to the subsequent use of that waste are U1 and T5. Where
an exemption doesn’t apply then the only other available option is a site based permit.
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Remediation Position Statement 13
Technology title
Permeable reactive barriers
Similar techniques
Reactive zones
Technology description
A permeable reactive barrier is an engineered treatment zone of reactive material that is
placed within the saturated zone in order to remediate contaminated groundwater as it flows
through it. A permeable reactive barrier has a negligible overall effect on bulk fluid flow rates
in the subsurface strata, which is typically achieved by construction of a permeable reactive
zone, or by construction of a permeable reactive ‘cell’ bounded by low permeability barriers
that direct the contaminant towards the zone of reactive media.
A permeable reactive barrier prevents or reduces contaminant flux whilst allowing
groundwater to flow through the barrier. The reactive materials either immobilise or transform
the pollutants, such that the treated groundwater down hydraulic gradient of the permeable
reactive barrier should not represent an unacceptable risk to water resources or other
receptors.
The most common design of permeable reactive barriers used to date are ‘funnel and gate’
and ‘continuous’ reactive barriers. ‘Funnel and gate’ permeable reactive barriers comprise
impermeable walls, such as sheet piles or slurry walls, which direct contaminated
groundwater to ‘permeable gate(s)’ containing the reactive material. ‘Continuous’ permeable
reactive barriers transect the pollutant plume flow-path with an unbroken wall of permeable
materials, which are combined with the reactive materials (for example a pea-gravel and
reagent filled trench that is constructed across the groundwater flow direction).
Organic contaminants
Typical contaminant groups treated
Inorganic contaminants
VOCs
9
Heavy metals
9
Halogenated hydrocarbons
9
Inorganics (NO3, SO4)
9
Non-halogenated hydrocarbons
9
Asbestos
8
PAHs
9
Miscellaneous
Dioxins/ furans
9
Corrosives
9
PCBs
9
Cyanides
9
Pesticides/ herbicides
9
Explosives
9
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Remediation Position Statement 13
Regulatory position
This type of process will generally be a waste recovery operation and so needs to be
regulated via an environmental permit (mobile plant or site based). No environmental
permitting exemptions apply. The process can be considered under the pilot trials/ small scale
remediation schemes enforcement position statement.
We will apply a site specific risk-based decision on whether to require an application for a site
based permit to be made for the treatment of groundwater in-situ by a permeable reactive
barrier. We will take account of the following aspects when reaching this decision:

a site risk assessment covering emissions to air has been undertaken as part of the
remediation project and full details of that risk assessment are submitted to us where the
remediation project is to take place at least five working days (or such other period as
agreed by us) before that project begins, and;

the treatment of the groundwater will not cause pollution of the environment, harm to
health or serious detriment to amenities, and is consistent with the need for the regulator
to exercise its relevant functions as required by paragraph 4(a) Schedule 9 of the
Environmental Permitting Regulations 2010.
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Remediation Position Statement 14
Technology title
Solidification and stabilisation
Similar techniques
Immobilisation, fixation
Technology description
Solidification and stabilisation are discrete processes that are often used together in order to
reduce the mobility of contaminants in soils. Solidification achieves a reduction in mobility by
converting the soil into a solid monolithic mass thereby reducing the permeability of the
material. Stabilisation reduces the availability of contaminants by changing their chemical
form (for example, precipitating metals in an insoluble compound) or increasing the strength
of their binding to a solid matrix. Solidification and stabilisation processes often involve a
combination of cement, fly ash, lime, clays or asphalt.
Solidification and stabilisation can be applied ex-situ using batch processing or in-drum
techniques, and in situ using a rotating auger or jet injection method.
Process streams generated during solidification/ stabilisation processes include:

gaseous and particulate emissions during mixing and setting;
process effluents during mixing.
Organic contaminants
Typical contaminant groups treated
Inorganic contaminants
VOCs
8
Heavy metals
9
Halogenated hydrocarbons
8
Inorganics (NO3, SO4)
9
Non-halogenated hydrocarbons
9
Asbestos
9
PAHs
9
Miscellaneous
Dioxins/ furans
9
Corrosives
9
PCBs
9
Cyanides
9
Pesticides/ herbicides
9
Explosives
8
Regulatory position
This type of process will generally be a waste recovery operation and so needs to be
regulated via an environmental permit (mobile plant or site based). No environmental
permitting exemptions apply. The process can be considered under the pilot trials/ small scale
remediation schemes enforcement position statement.
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Remediation Position Statement 14
Storage of treated waste
The temporary storage of excavated waste materials, for the purposes of reclamation,
restoration or improvement of land, is subject to control via either a mobile plant permit, a site
based permit, a permit exemption or as part of the pilot trials/ small scale remediation
schemes enforcement position statement.
The temporary storage of waste prior to collection for disposal or recovery off site may be
carried out under the non- Waste Framework Directive exemption for temporary storage at
the place of production pending its collection.
If the recovery operation is in-situ and this results in the permanent storage of waste, we will
apply a risk-based decision on whether to require an application for a site based permit to be
made for the keeping of this waste where it was treated. We will take account of the following
aspects when reaching this decision:

the use of treated material is suitable for the purposes of reclamation, restoration or
improvement at that site, and;

gaseous emissions after desorption and treatment;
solid and aqueous residues from abatement systems.
Organic contaminants
Typical contaminant groups treated
Inorganic contaminants
VOCs
9
Heavy metals
8
Halogenated hydrocarbons
9
Inorganics (NO3, SO4)
8
Non-halogenated hydrocarbons
9
Asbestos
8
PAHs
9
Miscellaneous
Dioxins/ furans
8
Corrosives
8
PCBs
9
Cyanides
9
Pesticides/ herbicides
9
Explosives
8
Regulatory position
This type of process will generally be a waste recovery operation and so needs to be
regulated via an environmental permit (mobile plant or site based). No environmental
permitting exemptions apply. The process can be considered under the pilot trials/ small
scale remediation schemes enforcement position statement.
Section 2.4.3 of Defra’s environmental permitting guidance on directive 2000/76/EC on the
incineration of waste (2nd edition, updated October 2009), states the remediation of
contaminated soil and the use of an afterburner for the abatement of emissions from plant
which is not an incineration plant are excluded from WID as these operations are not
considered incineration processes.
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Remediation Position Statement 15
Storage of treated waste
The temporary storage of excavated waste materials, for the purposes of reclamation,
restoration or improvement of land, is subject to control via either a mobile plant permit, a
site based permit, a permit exemption or as part of the pilot trials/ small scale remediation
schemes enforcement position statement.
The temporary storage of waste prior to collection for disposal or recovery off site may be
carried out under the non- Waste Framework Directive exemption for temporary storage at
the place of production pending its collection.
Use of treated material
Waste materials that have been subject to a successful treatment/ recovery operation (that is
treated to an agreed standard/ specification) may be re-used in accordance with the
Development Industry CoP.
If materials have not been successfully recovered then they will remain waste. The two
exemptions that could be relevant to the subsequent use of that waste are paragraphs U1
and T5. Where an exemption doesn’t apply then the only other available option is a site
based permit.
Related documents
Links
Contaminated land report 11 - Model procedures for the management of land
contamination.
Position Statement PS006 – Definition of Waste : Development Industry
Code of Practice.
Position Statement PS004 – Regulating trials of Waste Management
Activities
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