WREXHAM COUNTY BOROUGH COUNCIL

GUIDANCE ON THE DEVELOPMENT OF SITES WITH POTENTIAL LAND CONTAMINATION

1st Edition, October 2002

Prepared by the:Public Protection Department (Environmental Services Directorate)

The information in this leaflet has been provided in good faith, it should be borne in mind that the status of information may change, become out of date and that new working practices may develop. Ultimately it is the responsibility of the

person/company involved in the development and assessment of potentially contaminated land to apply up to date working practices in assessing the contamination status of a site and in determining the remediation requirements.

CONTENTS

Section Subject Page

1. Introduction 1

2. Assessing Contamination for the Development 2of Sites with Potential Land Contamination

3. Potentially Contaminated Sites 3

4. Summary of Procedures for Assessing 5Potential Land Contamination for Development Purposes

5. Phase 1 – A Desk Study 6

6. Phases 2 & 3 – Further Site Investigation 8

7. Phase 4 – A Remediation Strategy 9

8. Wrexham CBC’s Viewpoint 10

9. Contacts 11

10. Sources of Further Information 12

FURTHER COPIES OF THIS LEAFLET ARE AVAILABLE TO DOWN LOAD ON WREXHAM COUNTY BOROUGH COUNCIL’S WEB-SITE: www.wrexham.gov.uk

1. INTRODUCTION

This leaflet has been prepared by Wrexham County Borough Council (Wrexham CBC) to provide information which may assist in the preparation of planning applications and/or building regulations applications concerning the development of potentially contaminated land.

Land can be affected by contamination in the form of chemicals or gases in the soil and/or water, buildings, or other material on a site. Such sites are likely to be brownfield sites i.e. those which have been previously developed, often for commercial or industrial use.

As a result of the requirements to develop brownfield sites it is possible that some developments will take place on potentially contaminated sites. It is essential to ensure that potential contamination is adequately dealt with upon a change of land use, thereby ensuring the land is made suitable for its new use and presents no danger to the health and safety of people who come into contact with it. In some cases certain types of development (which are likely to be the most sensitive types e.g. housing) may not be suitable for sites with a certain type of contamination. In such cases the site may be better developed for another type of use, e.g. commercial or industrial. It is hoped that this leaflet, together with the Local Planning Guidance Note No 22 – Development of Sites with Land Contamination will go some way to ensuring that developed land remains safe.

This leaflet highlights the type and extent of investigations that need to be undertaken to ensure Wrexham CBC fulfils its statutory obligations under planning, building and environmental health legislation. In addition, this leaflet briefly explains the ‘link’ between the planning regime and the new contaminated land regime under Part IIA of the Environmental Protection Act, 1990 and Contaminated Land (Wales) Regulations, 2001.

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2. ASSESSING CONTAMINATION FOR THE DEVELOPMENT OF SITES WITH POTENTIAL LAND CONTAMINATION

Wrexham CBC aims to ensure that the development of brownfield sites will be carried out in an appropriate way. During development control procedures the planning department will require that prospective developers give appropriate consideration to any potential contamination issues at their sites.

Once potential contamination issues are thought to exist at a site, the assessment of the site will be to at least the level of that required under Part IIA (see below). Therefore, no further assessment of contamination issues on the site would be required under Part IIA provided that at a later date, (after the development) there is no subsequent change in the environment/development situation on and in the vicinity of the site.

Part IIA

Part IIA provides a framework for Council’s to manage potential contamination issues on sites where development is not taking place (i.e. not under the planning regime) with the object of ensuring that:‘by reason of substances in, on or under the land:-significant harm is being, or is likely, to be caused;-or pollution of controlled waters is being or is likely to be caused’.

The meaning of ‘substances’ and ‘significant harm’ should be in accordance with the statutory guidance provided by the National Assembly for Wales for the Part IIA regime.

This means that where land is identified as contaminated (under the strict definition detailed in Part IIA) Council’s are required to ensure that remediation takes place to return the land to a state that is suitable for its current use i.e. significant harm is not being caused or likely to be caused and it is not and will not cause pollution of controlled waters. Therefore, where contamination has not been addressed under the planning regime, sites will be assessed under Part IIA.

With regard to contamination site investigations and remediation of contaminated land, Wrexham CBC will consult and have regard to comments made by other statutory bodies, principally the Environment Agency.

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3. POTENTIALLY CONTAMINATED SITES

There are many former land uses that are potentially contaminating and some sites may have had a number of potentially contaminating uses, occurring either all at one time or at separate times. The (former) Department of Environment identified a number of such uses, see List 1. For each type of use, a profile is available which describes the: type of activities which may have taken place on the site; potential contaminants and locations where they may be found; factors that may affect the contamination; and migration and persistence of contamination.

In addition, the Construction Industry Research and Information Association (CIRIA) RP440 guidance lists potentially contaminative uses, as detailed in List 2.

Additional industries that the Council recognise may be contaminative are detailed in List 3. However, none of these lists are complete, but the information which is available is useful in designing site investigations, assessment of risk and remediation requirements.

List 1 - Department of Environment Industry Profiles

1. Airports2. Animal and animal products processing works3. Asbestos manufacturing works4. Ceramics, cement and asphalt manufacturing works5–18 Chemical works of various types19 Dockyards and dockland20–24 Engineering works: of various types26 Gas works, coke works and other coal carbonisation plants27-31 Metal manufacturing works of various types32 Oil refineries and bulk storage of crude oil and petroleum products33 Power stations (excluding nuclear power stations)34 Pulp and paper manufacturing works35 Railway land36 Road vehicle fuelling, service and repair: garages and filling stations37 Road vehicle fuelling, service and repair: transport and haulage centres38 Sewage works and sewage farms39 Textile works and dye works40-41 Timber products manufacturing works and Timber treatment works42 Waste recycling, treatment and disposal sites: drum and tank cleaning and recycling plants43 Waste recycling, treatment and disposal sites: hazardous waste treatment plants44 Waste recycling, treatment and disposal sites: landfills and other waste treatment or waste disposal sites45 Waste recycling, treatment and disposal sites: metal recycling sites46 Waste recycling, treatment and disposal sites: solvent recovery works49 Profile of miscellaneous industries incorporating:

Charcoal worksDry-cleanersFibreglass and fibreglass resins manufacturing worksGlass manufacturing worksPhotographic processing industryPrinting and bookbinding works

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List 2 - CIRIA RP440 Industry/Site Profiles

1. Iron and steel industry2. Metal processing industry3. Mining and extractive industries4. Non-ferrous metal smelting and refining5. Power stations (Gas/Oil/Coal)6. Shipbuilding sites7. Animal processing works8. Asbestos works9. Gas works 10. Paper Manufacture11. Printing industry12. Textile industry13. Wood treatment works14. Chemical plants15. Garages/Petrol stations16. Oil refineries/Storage sites17. Biocide production plants18. Incineration facilities19. Landfill sites20. Sewage works and farms21. Dockland sites22. Ministry of Defence land (munitions manufacture)23. Railway land24. Scrap yards

List 3 - Additional potentially contaminative uses not listed above:

1. Brickworks;2. Food processing industry;3. Laboratories for educational or research purposes;4. Premises housing dry cleaning operations; 5. Intensively cultivated agricultural land or buildings used for the storage of agro-chemicals; 6. Canal basins and wharves; 7. Waste heaps (including colliery spoil, lagoons, metalliferous waste etc…);8. Electricity supply industries;9. Industries using radioactive substances; and10. Demolition of buildings, plant or equipment used for any of the activities listed in Appendix A.

There are normally a series of 3 to 4 phases involved in assessing potential contamination issues at a site:

Phase 1 – Desk StudyPhase 2 – Further site investigation worksPhase 3 – Further more detailed site investigation worksPhase 4 – Remediation works

It may be that the findings of a Phase 1 investigation show that a Phase 2 assessment is not needed. Or following a Phase 2 investigation, Phases 3 and/or 4 are not needed.

IT IS IMPORTANT TO NOTE THAT ALL CONTAMINATION INVESTIGATIONS SHOULD BE CARRIED OUT ON A ‘SITE SPECIFIC’ BASIS SINCE NO ONE SITE IS THE SAME AS ANY OTHER.

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4. SUMMARY OF PROCEDURES FOR ASSESSING POTENTIAL LAND CONTAMINATION FOR DEVELOPMENT PURPOSES

YES NO

YES NO

YES

NO YES

YES NO

NO

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No further works are required.

Attempt to determine the past history of the site and surrounding area.

Does the site or area within influencing distance have an industrial history (see p3-4)?

Are there any known or suspected hazards at or within influencing distance of the site?

Does Wrexham CBC have any information on the site?

Carry out a Phase 1 contamination investigation (see p6)

Do the findings of the Phase 1 investigation require a further site investigation works (Phase 2)?

Carry out a Phase 2 contamination investigation (see p8)

Do the findings of the Phase 2 investigation require further site investigation works?

Do the findings of the Phase 2 investigation show that remediation is required.

No contamination investigation is required at this stage. However, if during site works evidence of contamination is uncovered, or further information comes to light, then Wrexham CBC should be contacted for advice since a Phase 1 investigation may now be needed.

No further contamination investigation works (i.e. Phase 2) are required.

Carry out a Phase 3 contamination investigation.

Do the findings of the Phase 3 investigation show that remediation is required?

Carry out remediation. No further

works are required.

5. PHASE 1 – A DESK STUDY

A desk study investigation of the site and land within influencing distance of the site should be undertaken by a suitable person. The desk study should comprise a report which assesses at least the following information in terms of potential contamination on or within influencing distance of the site:

Current and former uses of the site and the surrounding area, identifying in particular potential contamination hazards, potential receptors and pathways;

Geology (superficial deposits and solid (rock)); Hydrology (surface water); Hydrogeology (groundwater); and Pollution incidents on and within influencing distance of the site.

The information to be assessed can typically be obtained from the following sources:

Local history information e.g. historical maps (Ordnance Survey maps. often dating from the late 1800’s onwards), trade directories, books – found in libraries, county records offices, Landmark Information Group, museums and other local history sources;

Groundwater, surface water, pollution incidents, authorised processes and landfill site information can be provided by the Environment Agency;

Wrexham CBC can provide information on planning and environmental health issues; A mining report can be obtained from the Coal Authority which will detail, past, current and proposed mining

activities; The British Geological Survey may have maps and other information such as borehole logs for the site and

surrounding area and soil survey data; Aerial photographs; Information from the current site owner and/or vendor of the site; and A walkover survey.

A walkover survey of the site and the surrounding area should be undertaken by a suitable person. The inspection should identify:

Indications of potential contamination, for example: signs of chemical containers, tanks, odour, signs of spillages, made ground;

Topography and associated features; Soil type and condition; Surface water features and their condition (e.g. dis-colouration), including ponding, waterlogged ground,

water loving plants (e.g. reeds); Vegetation and its condition e.g. sparse, dead, stunted growth, species; Structures and site access, including evidence of services (e.g. overhead cables), signs of

movement/instability; and Historical features e.g. road names, local knowledge.

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Upon assessment of the above information, a conceptual model should be developed indicating potential pollutant linkages.

A Pollutant Linkage will comprise:

Source Pathway Receptor(a substance or group (a route by which a (that which could be substances with the potential source could reach a significantly harmed byto cause significant harm) receptor e.g. direct skin contact) the source e.g. a person)

The final desk study report should at least include: dated site plans showing the current, previous and proposed uses of the site; the sources of information investigated; the conceptual model; and the conclusions of the assessment. The following documents: 1, 2, 5, 11, 12 13, 15, 18 and 23 listed in Section 10 – Sources of Further Information, provide recognised best practice guidance on desk study investigations.

Failure to demonstrate familiarity with a sites former uses and land within influencing distance of the site and thus the potential for contamination to exist on the site will be regarded as

insufficient information. The Planning Department will usually expect a Desk Study report to accompany a planning application for a potentially contaminated site. If such a report is not

provided, the department may request the information before considering the application further, or alternatively a condition requiring an investigation may go on the planning

permission.

‘SUITABLE PERSONS’, ‘CONSULTANTS’ AND ‘SPECIALISTS’

A suitable person, consultant and/or specialist would require the following skills and knowledge to competently carry out any level of contamination investigation: have extensive experience in land contamination issues and possibly a suitable qualification (e.g.

environmental degree); have an understanding of the contaminated land regime (Part IIA) and its associated concepts; have experience in identifying the types of hazards that may affect a development; have experience in carrying out a desk study investigation, including a walkover survey and reporting the

findings of the study; be able to determine when further investigation is required i.e. Phase 2 investigation, and/or specialist advice

is required; and have experience in carrying out intrusive investigation works, risk assessments and report on the findings of

such works.

The person/company carrying out the contamination investigation works should have: appropriate professional indemnity insurance; an appropriate quality management system in place; use accredited laboratories; and an awareness of all occupational hygiene issues and health and safety legislation. For further advice on this matter see Section 9.

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6. PHASES 2 & 3 – FURTHER SITE INVESTIGATION

If the desk study indicates that contamination has occurred or is suspected, the developer should commission further site investigation works. Phase 2 works are generally intrusive however generally new methods, such as geophysical investigations, are becoming increasingly popular to give an initial indication of ground conditions.

In order to ensure that potential contamination issues at a site have been adequately addressed, Wrexham CBC will normally require that the objectives, scope and execution of the Phase 2 investigation is agreed prior to the works commencing. The report on the findings should then be provided to Wrexham CBC for consideration.

The design, methods and procedures available for Phase 2 works are numerous and should be entirely site specific, therefore, only a brief indication of what may be expected is detailed in this leaflet. It is advisable for the developer and person carrying out the investigation works (i.e. consultant) to consult the relevant best practice documents, most of which are listed in Section 10 – Sources of Further Information.

Generally Phase 2 works involve the collection of soil, leachate and/or water samples for analysis and long term gas and water monitoring (and sample collection) may also be carried out. These works can be done by various means and to varying degrees and cost. Where extensive and heavy contamination is suspected the further investigation works may be limited with a view to a more detailed and specific investigation subsequently being carried out (Phase 3) once the Phase 2 works have provided a general overview of the contamination. Typical Phase 2 works are:

Trial pits 4 - 5m deep holes often excavated by a digger in superficial deposits i.e. not rock. Useful to visually inspect ground conditions and collect soil and water samples.

Boreholes Boreholes can be drilled to almost any depth in any material, there are various drilling methods to suit most

types of ground, including rock. Can be designed for the long-term monitoring of water and gas. Soil samples for analysis can also be collected, although a reliable indication of ground conditions may be

difficult to determine (due to limited visibility) unless a large number of boreholes are drilled. In addition, there can be difficulties in determining the depth a soil sample has been collected from, although this is likely to be dependant on the type of drilling method employed.

The design of the investigation should take into account the findings of the desk study, services (e.g. underground electricity and gas facilities) etc… Samples should be collected based on good practice working methods and laboratory analysis should be conducted according to accredited

methods.

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The results of the site investigation should be detailed in a report and the following information should be included:

Plan of sample locations (to scale); Site investigation methodology (e.g. reasons for type of investigation, design of the investigation, sample

locations and depths, sample collection, storage and analysis procedures, field measurements and instruments used, laboratory used, rationale for choice of chemical analysis)

Ground conditions e.g. trial pit, borehole logs and an interpretation of the data; Results of any monitoring and laboratory tests; Significance of the results, including standards used for the assessment of the results and any risk assessment

procedures; Conclusions – including uncertainties; and Recommendations – including remediation proposals (if necessary).

The conclusions and recommendations of the report may indicate that further detailed site investigation works (Phase 3) are required. For example, it may not have been possible for the Phase 2 works to quantify/show the extent of the contamination or provide sufficient data to research/assess possible remediation works.

An inappropriate/incomplete assessment that fails to show the degree, extent of contamination, and/or the remediation (if any), that is required to ensure that:

‘by reason of substances in, on or under the land: - significant harm is being, or is likely, to be caused; - or pollution of controlled waters is being or is likely to be caused’

will be deemed as inadequate. As a result the Planning Department is likely to request further information before determination of an application for a proposed development, alternatively a

condition may be set on the planning permission.

7. PHASE 4 – A REMEDIATION STRATEGY

Following Phase 1 (and possibly Phases 2 & 3) contamination investigation works Wrexham CBC may agree that the proposed use for the site is suitable but subject to remediation works.

Wrexham CBC will require that any remediation works are carried out by a suitably qualified company and that the details of the works are approved prior to their commencement. Written quality assurance and a detailed written record of the remediation works carried out will be required by Wrexham CBC and we will expect these records (which are a means for demonstrating compliance) to be agreed in advance.

Failure to demonstrate that the remediation works have been carried out to the agreed standard will be regarded as insufficient and the site may be investigated under Part IIA at a later date – this may mean the site is designated as ‘contaminated land’ and further remediation works required as a result. Communication between the developer, Planning Department and Public Protection Department should prevent this occurring.

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8. WREXHAM CBC’S VIEWPOINT

At the pre-application stage or on receipt of a planning application, Wrexham CBC will have regard to the following issues:

1. Has the site or the surrounding land been statutorily classified as contaminated land by Wrexham CBC (Public Protection Department) under Part IIA of the EPA, 1990?

2. Is the site or the surrounding land recognised by Wrexham CBC (Public Protection Department) as potential contaminated land under Part IIA of the EPA, 1990?

3. As a result of current or previous land uses, or land uses within influencing distance of the site, is the site known or suspected to have contaminated ground?

4. Has the developer carried out a suitable contamination investigation of the site or are they in possession of information on contamination issues on or within influencing distance of the site?

5. Does the site require investigation prior to the determination of the planning application?

6. Does the site require remediation to ensure that by reason of substances in, on or under the land:- significant harm is being, or is likely, to be caused;- or pollution of controlled waters is being or is likely to be caused?

7. Has the developer carried out suitable remediation of the site or prepared suitable remediation proposals for the site?

On completion of works required by a planning condition and prior to development of the site, Wrexham CBC will have regard to the following issues:

1. Were the site investigation works suitable and complete?

2. Did the site investigation works identify the need for remediation works?

3. Were the remediation works suitable and carried out in accordance to the approved standard required – has the developer demonstrated compliance with the required standards?

4. Have any post monitoring works been completed in accordance with the approved requirements?

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9. CONTACTS

For further information or advice regarding planning issues please contact the Development Control section in the Planning Department at:

Lambpit Street 01978 292470PO Box 1290WREXHAMLL11 1WL

bob.dewey@wrexham.gov.uk

For further information or advice regarding contamination issues, including a list of environmental consultants (the list is not a comprehensive list and other sources of contact are suggested, nor is it an ‘approved list’ and clients should undertake their own checks to verify the suitability of a consultant) please contact the Scientific Officer in the Environmental Protection section of the Public Protection Department at:

Crown Buildings 01978 297041Chester RoadWREXHAMLL13 8ZE

angela.thompson@wrexham.gov.uk ORtoni.slater@wrexham.gov.uk

OR look for ‘land contamination’ on the web-site: www.wrexham.gov.uk

For further information or advice regarding funding issues please contact the Welsh Development Agency (WDA) at:

Jeff Porter MRICS 01745 586239Environment ManagerWelsh Development AgencyUnit 7, St Asaph Buisness ParkSt AsaphDenbighshireLL17 0LJ

jeff.porter@wda.co.uk

Sites designated as Contaminated Land under Part IIA are not eligible for WDA funding.

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10. SOURCES OF FURTHER INFORMATION

The following documents should be referred to where necessary, it should be noted that other documents exist and some are currently in preparation which are not listed here and may also be useful references.

1. British Standards Institution (BSI) ‘Code of Practice for Site Investigations: BS5930’, 1999

2. British Standards Institution (BSI) ‘Code of Practice for the Investigation of Potentially Contaminated Sites: BS10175: 2001’, 2001

3. Building Research Establishment (BRE) ‘BRE Report – Measurement of gas emissions from contaminated land’, 1987

4. Building Research Establishment (BRE) ‘BRE Report – Construction of new buildings on gas contaminated land’, 1991

5. Construction Industry Research and Information Association (CIRIA) ‘Special Publication 103 – Remedial Treatment for Contaminated Land – Volume III: Site investigation and assessment’, 1995

6. Construction Industry Research and Information Association (CIRIA) ‘Report 149 – Protecting development from methane’, 1995

7. Construction Industry Research and Information Association (CIRIA) ‘Report 150 – Methane investigation strategies’, 1995

8. Construction Industry Research and Information Association (CIRIA) ‘Report 151 – Interpreting measurements of gas in the ground’, 1995

9. Construction Industry Research and Information Association (CIRIA) ‘Report 152 – Risk assessment for methane and other gases from the ground’, 1995

10. Department of the Environment ‘Waste Management Paper No.27 – Landfill Gas’: 2nd Edition’, 1991

11. Department of the Environment ‘Contaminated Land Research Report – CLR No. 1 Volumes 1 & 2 - A framework for assessing the impact of contaminated land on groundwater and surface water’, 1994

12. Department of the Environment ‘Contaminated Land Research Report – CLR No. 2 Volumes 1 & 2 – Guidance on preliminary site inspection of contaminated land’, 1994

13. Department of the Environment ‘Contaminated Land Research Report – CLR No. 3 – Documentary research on industrial sites’, 1994

14. Department of the Environment ‘Contaminated Land Research Report – CLR No. 4 – Sampling Strategies for Contaminated Land’, 1994

15. Department of the Environment ‘Industry Profiles’ various titles, 1995

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16. Department of the Environment and The Welsh Office ‘The Building Regulations 1991 – Site Preparation and resistance to moisture, Approved Document C, 1992 Edition

17. Environment Agency National Groundwater and Contaminated Land Centre ‘Decommissioning Redundant Boreholes and Wells’

18. Environment Agency ‘Technical Aspects of Site Investigation: Volumes I and II – Research and Development Technical Report P5-065/TR’, 2000

19. Environment Agency ‘Secondary Model Procedure for the Development of Appropriate Soil Sampling Strategies for Land Contamination – Research and Development Technical Report P5-066/TR’, 2000

20. Environment Agency ‘Guidance on the Disposal of “Contaminated Soils”’, Version 3, April 2001

21. Environment Agency ‘Technical advice to third parties on pollution of controlled waters for Part IIA of the Environmental Protection Act’, 2002

22. Environment Agency ‘Contaminated Land Research Reports 7-10 and the CLEA Model’, 2002

23. Environment Agency/National House Builders Corporation (NHBC) ‘Guidance for the Safe Development of Housing on Land Affected by Contamination’, 2000

24. Environment Agency/Building Research Establishment (BRE) ‘Protective Measures for housing on gas-contaminated land’, 2001

25. Interdepartmental Committee on the Redevelopment of Contaminated Land (ICRCL) ‘Guidance on the assessment and redevelopment of contaminated land: ICRCL 59/83, 2nd Edition’, July 1987

26. National Assembly for Wales ‘Statutory Instruments 2001 No. 2197 (W.157) Environmental Protection, Wales – The Contaminated Land (Wales) Regulations, 2001

27. National Assembly for Wales ‘Remediation of Contaminated Land – National Assembly for Wales guidance to enforcing authorities under Part IIA of the Environmental Protection Act 1990’, November 2001

28. Statutory Instrument 1989 No. 1147 & 2000 No. 3184 ‘The Water Supply (Water Quality) Regulations, 1989 and 2000

29. Statutory Instrument 1996 No. 3001 ‘The Surface Waters (Abstraction for Drinking Water) (Classification) Regulations, 1996

30. Statutory Instrument 1998 No. 2746 ‘The Groundwater Regulations, 1998

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