The Ground Risk Bands are an indication of the effort needed to conduct a preliminary risk assessment and any subsequent intrusive site investigation, quantitative risk assessment and remediation. The higher the Band the greater the severity of the potential contamination and the higher the financial investment likely to be required to manage any risk to ensure the site is suitable for its intended end use. Where groundwater could be affected, additional risk assessment and potentially remediation effort may be required. The need for any site remediation is established during the assessment of the potential risks any contamination on could pose to people and water. Past experience has shown that remediation is more likely to be needed for the higher Ground Risk Bands.
Band I sites have previous potentially contaminative land uses limited to land use category A and B with very limited influences from formal records of pollution and/or pathways through which deep contamination can migrate (boreholes and mine entries). The sensitivity of the water environment is minimal represented mainly by low to medium groundwater vulnerability and limited surface water and/ or shallow groundwater present at or near to the site.
Band II sites have previous potentially contaminative land uses mainly in land use category A and B with some category C sites. Formal records of pollution and/or pathways through which deep contamination can migrate (boreholes and mine entries) show the Sites are only influenced in a limited way. The sensitivity of the water environment is negligible for land use category A and B sites and minimal for land use category C sites, characterised by medium to high to low groundwater vulnerability respectively. Land use category A and B sites sometimes have surface water features and/ or shallow groundwater on or close to the site, but this is not the case on land use category C sites.
Band III sites have previous potentially contaminative land uses comprising mainly land use category B and C with some category D sites. Some sites are characterised by multiple records of C or D land use categories. Sites are influenced by pathways through which deep contamination can migrate (boreholes and mine entries) but records do not indicate they are particularly influenced by documented pollution. The sensitivity of the water environment is medium to high for land use category A and B but low to medium for land use category C and D sites. Surface water is usually present and shallow groundwater is sometimes present for land use category A and B sites. Surface water is much less significant for category C site and is not present on or near land use category D sites.
Band IV sites have previous potentially contaminative land uses consisting mainly of category C and D sites with some characterised by multiple records of category C or D land uses. Sites are influenced by pathways through which deep contamination can migrate (boreholes and mine entries) but not particularly by recorded pollution. The sensitivity of the water environment is medium to high for land use category B and C but generally low to medium for category D sites. Surface water is present and shallow groundwater is sometimes present at land use category B sites. Surface water is mostly present for C sites and sometimes present for D sites.
Band V sites have previous potentially contaminative land uses consisting mostly of category D sites with most being characterised by multiple records of C or D land uses. Sites are influenced by pathways through which deep contamination can migrate (boreholes and mine entries) and by recorded pollution. The sensitivity of the water environment is medium to high with surface water present with/without shallow groundwater at most sites.
For further information about land contamination and risk assessment consult the Environment Agency guidance Land Contamination: Risk Management first published in October 2020.
Historical land use influences whether soil and groundwater contamination might be present at a site. Former land uses include a variety of activities and processes that result in surplus, by-product and/ or waste materials. Each of these has the potential to contaminate soil and groundwater if they are not managed properly. Four land use categories have been defined for the purpose of this tool (A to D) and assigned to land uses that appear on historical ordnance survey maps. Category A sites represents a lower potential for contamination and Category D sites represent a higher potential for contamination. The severity of potential contamination increases from A to D. Indicative land uses for each category are shown below: