Contaminated Land

Contaminated land
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Information on Panshanger airfield

Contaminated land guide

Aim

This guide is intended to assist developers and their consultants in meeting the requirements of Planning Permissions where conditions relating to contaminated land are attached. It does not form part of any Planning Permission and is intended only to assist in complying with the planning condition. A glossary of terms is contained at the back of the document.

Liaison with the local authority

An early and close liaison should be established between the developer, his consultant, the Council's Environmental Health and Planning Departments and the Environment Agency. This is crucial in creating an efficient and open process where delays are minimised and the site risk assessment can be incorporated into the development timetable at the outset.

Failure to comply with the planning condition may have the following consequences:-

Delay in progressing the development.
Enforcement action by the Planning Authority
Increase in costs if further investigation is required.
The land being determined as contaminated land and placed on the public register, under Part IIA of the Environmental Protection Act 1990.
Problems with the future sale of the land or buildings.

The assessment of contaminated land

Official guidance relating to contaminated land in the UK promotes a risk-based approach to dealing with soil and groundwater contamination. The aim is to protect human health and the environment on a "suitable for use" basis. Fundamental to the risk-based approach is the source – pathway – receptor (or target) concept. Put simply, before a source of contamination can pose a risk to a receptor ( e.g. a human being or groundwater) there has to be a pathway by which the receptor can come into contact with the contamination. Such pathways can include, migration in groundwater (or in the case of gas, through the ground, service pipe conduits, etc.), vapour inhalation, ingestion and skin contact. If no pathway exists, the contamination itself may well be a hazard, but as it does not pose a risk, no remediation is required. If source – pathway – receptor conditions exist at a site, the significance of the risk posed must be assessed and appropriate remedial measures considered as a result of that assessment.

Where official guidance has been produced, the investigation and remediation of land should be carried out in accordance with those standards and recommendations. The need for care when selecting a competent and suitably experienced consultant is fundamental to producing a credible and appropriate assessment. The Council will reject reports and/or require further information in cases where work has not been carried out in accordance with good practice or fails to establish confidence in the findings and conclusions reached. Work is most often rejected where:

Work starts without establishment of effective dialogue and the Council’s specific agreement to the proposals
Work deviates from agreed methods without prior agreement
The development begins before all assessment work and remediation proposals are agreed with the Council

The Council wishes to avoid these circumstances and recommends most strongly that developers maintain close and effective dialogue at all stages of the process. It must also be stressed that the responsibility for completing work and providing information rests entirely with the developer and their advisors where appropriate.

Environmental risk assessment

It is normal practice for an environmental site assessment to be carried out in 3 distinct phases.

Phase One:

The purpose of a phase one risk assessment is to

establish whether there have been any potentially contaminative uses on the site itself or nearby land;
identify the presence of any receptors, existing and proposed;
establish whether the potentially contaminative use could impact on receptors at the site or its neighbourhood;
design a phase two risk assessment. (if appropriate) A phase one risk assessment report should indicate all sources of research and consist of: Historical Research of the Site: Relevant sources of information include:- historical and current OS maps trade directories planning records libraries archives local knowledge

A phase one risk assessment report should indicate all sources of research and consist of:

Historical Research of the Site

Relevant sources of information include:

historical and current OS maps
trade directories
planning records
libraries
archives
local knowledge

Environmental Setting

Relevant subjects include:

geology
hydrogeology
surface water features
designated ecological areas
water abstraction points
discharge consents, etc.
landfills within 250m of site

Initial Site Walkover/Survey

This should include:-

site layout neighbouring properties – nature and location
sources of obvious contamination such as signs of stressed flora and fauna
structures indicating potential contamination, e.g. fuel tanks or asbestos lagging inside buildings

Conceptual Model

This will show the potential sources of contamination, the nature of the contamination, the potential receptors and potential migration pathways. It will identify any potential contamination of the site and the subsequent design of the phase two investigation, (if this is then deemed necessary). A brief should now be agreed between the client and contractor.

Accepted procedures are laid down in “Guidance on Preliminary Site Inspection of Contaminated Land” CLR Report No. 2 volumes 1 and 2.

Phase Two:

The purpose of a phase two risk assessment is to characterise the risk through a site specific survey and so determine the need for remediation. The report should include details of:

A Copy of the Brief between the Client and Contractor
Objectives of Investigation: These should be drawn from the findings of phase one.
Investigation Strategy:

Field Testing

sampling locations marked on a site plan, targeted to those areas of the site where contamination is likely
nature and number of samples for chemical, hydrogeological and gas testing
procedures for sampling, handling, storage, collection and transport
use and calibration of appropriate equipment
A written justification of the proposed sampling regime in respect of the requirements of BS10175:2001 Code of Practice on the Identification of Potentially Contaminated Land and its Investigation.

Laboratory analysis

Use of UKAS/MCERTS accredited procedures.
Original authorised results and any laboratory interpretation of results

Risk Assessment

This is based upon the results of sampling in the context of the proposed end use. Use of authoritative guideline values such as the UK Soil Guideline Values* (in conjunction with CLR 7-10 Reports) must be qualified and appropriate. The contaminant concentration used for comparison must also be stated i.e. average, maximum, appropriate percentile.

Where Soil Guideline Values (SGVs) are not available for the appropriate pollutants, suitable site specific criteria must be derived in accordance with CLR9, Collation of Toxicological Data and Intake Values for Humans, and submitted for approval. Or alternatively, if it can be shown that CLEA is not the appropriate model, then other packages (with the Council’s agreement) can be used, for example SNIFFER, RBCA, RISC – Human, Risk Assistant. Use of such models must be qualified and appropriate. All model uncertainties and assumptions must be stated and the risk estimate produced by the model fully explained. Your Environmental Consultant will be able to advise you further on these requirements.

Risk Evaluation

The risk must be quantified and its acceptability determined in the context of the proposed site use. A decision can then be reached as to the need for risk management or remedial action.

Accepted and Authoritative procedures are included in:

BS 10175:2001 Code of Practice on the Identification of Potentially Contaminated Land and its Investigation.
Sampling Strategies for Contaminated Land CLR Report No. 4.
Environment Agency (EA)/NHBC 2000 Guidance for the Safe Development of Housing on Contaminated Land
EA Secondary Model Procedures for the Development of Appropriate soil Sampling Strategies for Land Contamination (2001).
DETR 2000 Guidelines for Environmental Risk Assessment and Management.
Methodology for the Derivation of Remedial Targets for Soil and Groundwater to Protect Water Resources. Environment Agency R and D Publication 20.
Waste Management Paper 27 – Landfill Gas.
CLEA ( Contaminated Land Exposure Assessment Model)
The UK Approach for Evaluating Human Health Risks from Petroleum Hydrocarbons in Soils (EA Report P5-080/TR3)

Phase Three:

Phase three is the Remediation Strategy, the objectives of which should be agreed with the Council's Planning Department via the Environmental Health Officer and where necessary, the Environment Agency. The report should include:

a full description of the contamination issues on site with reference to the conceptual model.
A full evaluation of remedial options.
the remediation objectives and remediation plan.
a health and safety plan (you may need to take appropriate action under the CDM Regulations 1994 more information can be obtained from www.hse.gov.uk)
a work plan
a verification/completion report to include waste transfer notes for any exportedmaterial and analysis of all soil bought onto site.  details of any required long term monitoring/maintenance measures

Other considerations

Unexpected Discoveries

These may come to light during remediation or development and may include underground structures such as fuel storage tanks or other sources of contamination. The remediation strategy should make contingencies to deal effectively with unexpected discoveries including notification to the Council and any other interested agencies such as the Environment Agency, Health and Safety Executive, etc. If necessary, a specific risk assessment, or additional sampling, may also be needed.

Sustainability

This authority is committed to the principles of sustainability. All Phase Three reports should include an evaluation of available options. Reports that only consider removal from site without carrying out a full evaluation of all available remedial options will not be accepted.

Record Keeping

The need for comprehensive and accurate record keeping is fundamental to safe and effective remediation and must be included in the strategy. These records will also form the basis of a contaminated land review by the Council in the future under Part IIA of the Environmental Protection Act 1990. If the site records can demonstrate that appropriate and durable remediation works have been carried out and they remain effective, the Council will not proceed with further regulatory action under Part IIA.

Useful Contacts and Addresses for Consultants and Associated Services

Association of Consulting Engineers:

Alliance House

12 Caxton Street

Westminster

London

SW1H OQL

Tel: 0207 222 6557

Fax: 0207 222 0750

Web: http://www.acenet.co.uk

Provides a free listing of all its members categorised by way of 18 specialism’s, one of which is contaminated land.

Association of Geotechnical and Geoenvironmental Specialists:

Forum Court

83 Copers Cope Road

Beckenham

Kent

BR3 1NR

Tel: 0208 658 8212

Fax: 0208 663 0949

Web: http://www.ags.org.uk/

Members are both consultants and contractors involved in the geo-environment offering services in ground investigation, contaminated land assessment and remediation, laboratory testing and analysis, environmental audits, hydrogeology and pollution control. Copies of membership list and details of publications are available from the Administrator.

British Consultants Bureau:

1 Westminster Palace Gardens

1-7 Artillery Row London

SW1P 1RJ

Tel: 0207 222 3651

Fax: 0207 222 3664

Web: http://www.bccb.co.uk/

A non-profit making multidisciplinary organisation of almost 300 independent consultancy firms and individuals. It has an environmental group representing engineers, architects, environmentalists, lawyers, economists and other disciplines. Direct enquiries are accepted to assist in identifying appropriate consultants.

Environmental Data Services (ENDS):

40 Bowling Green Lane

London

EC1R 0NE

Tel: 0207 814 5300

Fax: 0207 415 0106

Web: http://www.ends.co.uk

Holds a detailed database of consultants and offers a free service to anyone (including Non-members); searches usually provide a minimum of five consultants meeting the criteria provided. ENDS directory of Environmental Consultants is a detailed directory of over 400 consultancies which includes information on choosing a consultancy. ENDS also publish an analysis of the environmental consultancy market.

UK Accreditation Services:

21-47 High Street

Feltham

Middlesex

TW13 4UN

Tel: 0208 917 8400

Web: http://www.ukas.com/

Technical enquiry office answers specific questions/enquiries relating to laboratories involved in chemical analysis of contaminated land. Directory of accredited laboratories revised annually

Specialist in Land Condition: (SiLC)

Institute of Environmental Management & Assessment

St Nicholas House

70 Newport

Lincoln

LN1 3DP

Tel: 01522 540069

Web: http://www.silc.org.uk

A SiLC Professional and Technical Panel (PTP) established to develop a system for the registration of individuals completing the Land Condition Record (LCR). The use of a registered SiLC will give the highest level of credibility to the information provided. The above web site address gives a list of registered SiLC’s. The Council does not recommend any of the consultancies listed, but is aware that they provide services in relation to contaminated land

Contaminated Land