UNIVERSITY OF EXETER CAMBORNE SCHOOL OF MINES

1. UNIVERSITY OF EXETERCAMBORNE SCHOOL OF MINES CSM M104 LAND MANAGEMENT AND LAW

2. Management of Contaminated Land Importance of contamination for land management and development: important factor in redevelopment of land extensive contamination in industrial areas often in prime development locations risk and uncertainty legal liability site investigation costs remediation (clean up) costs affects land value planning and regulatory aspects constraints on redevelopment options

3. Contaminated land and urban regeneration in SheffieldTop: East Hecla Works, Meadowhall, 1930;Centre: Meadowhall site, 1987Bottom: Meadowhall Shopping Centre, now

4. Contaminated land and rural regeneration in Cornwall

5. Some definitions Contamination represents or potentially represents an adverse health or environmental impact due to the presence in significantly high concentrations of potentially hazardous substances (natural or anthropogenic). Pollution was defined by the Royal Commission on Environmental Pollution (1984) as "the introduction by man into the environment of substances or energy liable to cause hazards to human health, harm to living resources and ecological systems, damage to structures or amenity, or interference with legitimate uses of the environment. Substances introduced into the environment become pollutants only when their distribution, concentration or physical behaviour are such as to have undesirable or deleterious consequences." Derelict land is defined as "land so damaged by industrial or other development that it is incapable of beneficial use without treatment" (Department of the Environment, 1995). Dereliction does not necessarily imply contamination but can mean physical dereliction that requires some kind of physical treatment. Brownfield land: previously developed land.

6. Sources of contamination Chemicals / Petrochemicals Metals Energy Transport Mineral extraction Waste disposal sites Water supply and sewage treatment Miscellaneous sources Summary in Table 1

7. Principal contaminants The Interdepartmental Committee on the Redevelopment of Contaminated Land (ICRCL, 1987) recognised six major groups of contaminants: inorganics, notably heavy metals (As, Pb, Cu, Cd, Cr, Ni, Hg, Zn) and cyanide toxic organic compounds (polynuclear aromatic hydrocarbons (PAH), phenol) anionic species (sulphate, sulphide, chloride) substances with hazardous physical properties (asbestos, radioactive material) gaseous contaminants (especially methane) combustible substances (oil, tar, coal dust etc.) [NB the ICRCL guidelines have been superseded by CLEA/SGV]

8. Hazards associated with contaminated sites direct ingestion of contaminants uptake by food crops phytotoxicity contact hazard corrosion hazard to structures/services explosion risk and dust pollution of surface and groundwater Summary in Table 2

9. Henwythva (Camborne, Cornwall): housing development on the site of a former arsenic mine. High levels of arsenic in the soil created both environmental and health and safety concerns during redevelopment of the site. Here (1997), work is suspended under H&S legislation while H&S concerns are addressed.

10. Henwythva (Camborne, Cornwall): housing development on the site of a former arsenic mine. Here (2004), work has continued, the contaminated soil has been removed to landfill and the development is completed.

11. Legislative background The New Regime for Contaminated Land: Part IIA of the Environmental Protection Act 1990, inserted by Section 57 of the Environment Act 1995, provides a new regulatory regime for the identification and remediation of contaminated land The new regime is described Defra Circular 01/2006 Environmental Protection Act 1990: Part 2A Contaminated Land and the Contaminated Land (England) Regulations, 2000     Further guidance on the New Regime for Contaminated Land a and list of contaminated land publications can be found at the DEFRA 'Contaminated Land' website See also the Environment Agency publication Dealing with Contaminated Land in England

12. Legislative background (2) General environmental legislation also applies during the investigation, remediation and redevelopment of contaminated sites, notably the Environmental Protection Act 1990, Part II Waste to Land (which establishes procedures for handling wastes from contaminated sites and elsewhere), the Water Resources Act 1991 (which protects controlled waters), and the Landfill (England and Wales) Regulations 2002 (which classifies landfills for hazardous, non-hazardous and inert wastes and thus limits the disposal options for waste derived from contaminated sites and elsewhere) (see http://www.netregs.gov.uk for full list) Legislation covering health and safety must also be observed (Health and Safety at Work etc. Act 1974, COSHH Regulations 2002) All UK legislation since 1988 can be accessed online at http://www.legislation.hmso.gov.uk/acts.htm and all statutory instruments since 1987 at http://www.hmso.gov.uk/stat.htm

13. Responsibilities Section 36 of the Circular states that the enforcing authority (the Local Authority except in the case of Special Sites when it is the Environment Agency – see DEFRA Circular 01/2006 p. 158) will have four main tasks: (a) to establish who should bear responsibility for the remediation of the land (the “appropriate person” or persons); (b) to decide, after consultation with the appropriate person, the landowner and the Environment Agency, what remediation is required in any individual case and to ensure that such remediation takes place, either through agreement with the appropriate person, or by serving a remediation notice on the appropriate person if agreement is not possible or, in certain circumstances, through carrying out the work themselves; (c) where a remediation notice is served, or the authority itself carries out the work, to determine who should bear what proportion of the liability for meeting the costs of the work; and (d) to record certain prescribed information about their regulatory actions on a public register.

14. “Appropriate Persons” Under the provisions concerning liabilities, responsibility for paying for remediation will normally follow the “polluter pays” principle. In the first instance, any persons who caused or knowingly permitted the contaminating substances to be in, on or under the land will be the appropriate person(s) to undertake the remediation and meet its costs (‘Class A Person’). If it is not possible to find a Class A Person, responsibility will pass to the current owner or occupier of the land (‘Class B Person’). (This does not apply where the problem is solely one of water pollution, liabilities for which were already established prior to the introduction of Part IIA.) Where there is no appropriate person, the enforcing authority has the power to carry out a remediation action. Responsibility will be subject to limitations (e.g. where hardship might be caused) as set out in Part IIA and in the statutory guidance in the Circular.

15. Management of contaminated materials is particularly important. This gasworks site in Devon was being redeveloped as a swimming pool when work was interrupted by concerns over disposal of the waste. Highly contaminated material (dark material in centre foreground) had been mixed with relatively inert material (pale material in background), preventing landfill disposal of the mixed waste and necessitating high-cost incineration.

17. Hazards and risks Hazard: "the capacity to produce a particular type of adverse health or environmental effect" Risk: "the probability that an adverse outcome will occur in a person, a group or an ecological system [the 'receptor'] that is exposed to a particular dose or concentration of a hazardous agent; i.e. it depends on both the level of toxicity of hazardous agent and the level of exposure" (both definitions from UNEP, 1994). Hazard and risk are different Contaminated land investigations assess risk through determination of ‘pollutant linkages’

18. Pollutant linkages contaminants - pathways - receptors Contaminants: hazardous substances in the environment Pathways: direct geological pathways direct man-made pathways indirect biological pathways dispersion of contaminated dust Receptors: individuals, groups or ecological systems exposed to hazard

20. Site investigation Framework set out in BS10175:2001 Establish objectives (Table 3) Phase 1: Desk Study (next slide) & Site Reconnaissance Table 4 Preliminary Risk Assessment Preliminary Conceptual Model Phase 2: Preliminary Site Investigation (Refinement of Conceptual Model) Non-intrusive and intrusive investigations Main Site Investigation Risk Assessment

21. Phase 1 Desk Study 'Desk Study' - the collation and evaluation of existing information on the site. This information should include (BSI 1988, 2001): history of the site with details of owners, occupiers and uses processes used on the site along with the locations of plant, storage areas for raw materials, products and waste, and methods of waste disposal layout of the site, including roadways and hard cover location of services (past and current) above and below ground, including gas, water, electricity, drains and sewers presence of waste disposal tips, abandoned pits and quarries, with or without standing water mining history including possible locations of shafts, stopes and voids geological, hydrogeological, meteorological and geochemical information information on the distribution and movement of surface and groundwater information on special or unusual characteristics or history of the site presence of any naturally occurring hazardous material constraints on an intrusive site investigation potential receptors of contamination

22. Sources of Information for Desk Study Sources of information, summarised in BSI (1988, 2001), should include: Environment Agency / Scottish Environmental Protection Agency / Environment and Heritage Service (Northern Ireland); local authorities; Health and Safety Executive and Fire Authorities; National Radiological Protection Board; maps, plans and charts published by the Ordnance Survey, British Geological Survey etc., and unpublished sources that might be held at County Record Offices etc.; books and other published reports and technical papers; directories; photographs (including aerial photographs, postcards); site records and reports; meteorological and hydrological records.

23. Phase 2 Non-intrusive Investigations Measurement of environmental parameters using geophysical methods, including: conductivity surveys electrical resistivity surveys ground penetrating radar magnetic profiling microgravity surveys seismic refraction infra-red photography infra-red thermography radiation surveys Use of gamma-ray spectrometer for radiation survey (right)

24. Phase 2 – Intrusive investigations Surface sampling Trial pits Boreholes Groundwater (Table 5) Guidance in BS10175:2001 (Ref. 2)

25. Interpretation of Contaminant Data Interdepartmental Committee on the Redevelopment of Contaminated Land (ICRCL) Trigger concentrations, 1987 (withdrawn and replaced by CLEA/SGV) Contaminated Land Exposure Assessment (CLEA) Soil Guideline Values (SGV)

26. ICRCL Trigger Concentrations Two different trigger concentrations were identified in the ICRCL recommendations for specific end-uses of contaminated sites (Table 6): a threshold value, below which samples are not considered to be contaminated an action value, above which samples are considered to be so contaminated that remediation (cleanup) is required if values are between the trigger and action values, professional judgement is required to decide whether or not the contamination present required remediation This represents a risk-based approach based on the proposed end-use of the site (unlike, for example, the Dutch standards, published in 2000, which are standards-based – the same value for all end-uses) The ICRCL recommendations have been replaced through CLEA by the Soil Guideline Values (SGV)

27. Contaminated Land Exposure Assessment (CLEA) The Contaminated Land Exposure Assessment Model (CLEA) describes the conceptual exposure models for each standard land use Soil Guideline Values are derived for specified end uses (residential with and without vegetable growing, allotments, and commercial / industrial) CLEA sets out the technical basis for modelling exposure

28. Soil Guideline Values (SGV) SGVs help determine if a site represents an actual or potential risk to human health in the context of the existing or intended use of the site If the contaminant concentration is below the guideline value, the site is considered safe; if values are higher than the appropriate guideline, further site investigation is required - SGVs thus represent ‘trigger values’ SGV guidelines, which were updated in 2009, are now available for eleven key contaminants (click here to download) Soil Guideline Values (SGV) have replaced ICRCL recommendations but a full set of SGVs for all contaminants is not yet available

29. Remediation options Monitored natural attenuation (MNA) Removal to landfill or incineration (‘dig and dump’ - less common since Landfill Regulations, 2002). Case Study: asbestos-contaminated mine site On-site containment / encapsulation Soil washing (separation of contaminated/inert fractions) Treatment and stabilisation (with industrial minerals or cement) Bioremediation (of organic contaminants) Others (e.g. vacuum extraction, in situ vitrification) See CL:AIRE Online Library for case studies See Environment Agency Remedial Treatment Data Sheets for bioremediation and MNA

30. References References: (1) British Standards Institution. Code of practice for the identification of potentially contaminated land and its investigation. Draft for Development. BS DD 175 (1988) (now withdrawn; superseded by BS 10175:2001). (2) British Standards Institution. BS 10175:2001. Investigation of potentially contaminated sites. Code of practice. (3) Department of the Environment. Survey of Derelict Land in England 1993. HMSO, London. (1995). (4) Interdepartmental Committee on the Redevelopment of Contaminated Land. Guidance on the assessment and redevelopment of contaminated land. ICRCL Guidance Note 59/83. Second Edition. HMSO (1987).(4) Royal Commission on Environmental Pollution. 10th Report: Tackling Pollution - Experience and Prospects. Cmnd 9194. HMSO, London (1984). (5) Royal Commission on Environmental Pollution. 10th Report: Tackling Pollution - Experience and Prospects. Cmnd 9194. HMSO, London (1984). (6) United Nations Environment Programme. Risk Management of Contaminated Industrial Land. Training Resource Package. UNEP, Paris (1994).