Internal Guidance Note 2 LEAD Generic Assessment Criteria [GAC] September 2015

YAHPAC IG 2.2 Internal Guidance Note 2 LEAD Generic Assessment Criteria [GAC] September 2015 Purpose This internal guidance note has been prepared for use by YAHPAC local authorities to assist in the reviewing of reports where the former lead Soil Guideline Value [SGV] of 450mg/kg has been used and submitted through the planning regime. Caveat This guidance is intended to serve as an informative and helpful source of advice. The contents of this internal guidance note are not binding to any of the individual YAHPAC local authorities. The final decision regarding the subject matter of this note rests solely with each individual authority. Site specific communication with an individual authority should be undertaken to establish their position. Readers must note that legislation, guidance and practical methods are inevitably subject to change and therefore should be aware of current UK policy and best practice. This note should be read in conjunction with prevailing legislation and guidance, as amended, whether mentioned here or not. Where legislation and documents are summarised this is for general advice and convenience, and must not be relied upon as a comprehensive or authoritative interpretation. Ultimately it is the responsibility of the person/company undertaking the risk assessment to apply up-to-date working practices and requirements. Background The former soil guideline value [SGV] of 450 mg/kg, as a generic screening value for lead in soil was withdrawn in 2009, when the Environment Agency released a new version of the Yorkshire & Humberside Pollution Advisory Council Howard Building, College Lane, Rotherham, S65 1AX Tel: 01709 823105 Fax: 01709 823147 CLEA model and amended technical guidance. Although some SGVs were reproduced by the EA using the new approach, they did not include lead. The UK Government has now published Category 4 Screening Levels (C4SLs), to help identify land where the level of risk from contamination is acceptably low, in accordance with the revised Part 2A Contaminated Land Statutory Guidance. C4SLs have been developed using the latest version of the CLEA model as well as up to date toxicology data. The C4SLs for lead are as follows: RESIDENTIAL RESIDENTIAL WITH WITHOUT ALLOTMENT COMMERCIAL POS [RESI] POS [PARK] HOMEGROWN HOMEGROWN PRODUCE PRODUCE 200mg/kg 310mg/kg 80mg/kg 2300mg/kg 630mg/kg 1300mg/kg The withdrawn SGV for lead was based on a blood lead concentration of 10ug/dL. However, since then there has been uncertainty over the relationship between environmental lead exposure and blood lead concentrations, and also the level of exposure which can cause measurable health effects, particularly in children. There is now a consensus in the international toxicology community that a threshold of 10ug/dL is no longer considered health protective. The new C4SL is based on a more precautionary blood lead level of 3.5ug/dL. The Government’s Impact Assessment agreed during the revision of the Part 2A Statutory Guidance was developed on the basis that C$SLs could be used under the planning regime, as well as within Part 2A. This intent is reflected within the Planning Practice Guidance on Land Affected by Contamination. Exceeding a C4SL does not necessarily mean that the land is contaminated, only that further investigation or assessment may be required. Whereas SGVs represent minimal risk levels, C4SLs represent a more pragmatic 'low' level of risk, which is still strongly precautionary. Given that the C4SLs have been published by the UK Government, these are considered to be authoritative and robust, and appropriate to use as screening values for planning purposes. Other organisations have derived their own generic screening values for lead, using the updated CLEA model, and these are commercially available (e.g. Atrisk soil screening values from Atkins). Advice 1. Given these developments, it is felt that the withdrawn SGV for lead is not appropriate for use as a generic screening level, and that a value which has been derived using the up to date CLEA model and toxicology data should be used. 2. Exceeding a GAC (e.g. C4SL) for lead and other contaminants does not necessarily mean a site needs remediating, but that further assessment or justification is required. Yorkshire & Humberside Pollution Advisory Council Howard Building, College Lane, Rotherham, S65 1AX Tel: 01709 823105 Fax: 01709 823147 3. The Normal background concentrations (NBC’s) for lead and other contaminants, as defined in the Defra research project undertaken by the British Geological Survey (ref. SP1008), should not usually be considered within a planning context. They are intended to give guidance on what are normal levels of contaminants in English soils for the purposes of the revised Part 2A Contaminated Land Statutory Guidance. Further information is available at http://www.bgs.ac.uk/gbase/NBCDefraProject.html Yorkshire & Humberside Pollution Advisory Council Howard Building, College Lane, Rotherham, S65 1AX Tel: 01709 823105 Fax: 01709 823147 .

Load more