Band I sites may be affected by localised geotechnical hazards, including differential settlement, resulting from the presence of artificial ground. Band I sites may be within 250 m of former/ operating landfill sites which present potential ground gas hazards. Band I sites are occasionally influenced by local ground stability hazards caused by ground conditions caused by human activity e.g. coal mining but also occasionally by natural geological conditions e.g. compressible ground.
Band II sites are almost all potentially affected by ground gas hazards, although none within the current portfolio of sites are on or close to former or operating landfill sites. Most Band II sites are affected by localised geotechnical hazards arising from the potential presence of artificial ground and differential settlement. Band II sites are often influenced by ground stability hazards due to natural geological conditions e.g. compressible ground.
Band III sites are often affected by multiple hazards and are almost always located within an area affected by land instability and ground gas from historic coal mining. Some sites are also on or near a former or existing landfill. Band III sites may be affected by localised/ regional geotechnical hazards arising from artificial and in some cases natural ground with the potential to cause significant differential settlement.
Band IV sites are affected by multiple hazards and are within areas affected by land instability and ground gas from historic coal mining. Some sites are also on or near a former or existing landfill. Most Band IV sites may be underlain by artificial and, in some cases, natural ground with the potential to cause significant differential settlement.
Band V sites are affected by multiple hazards and are within areas affected by coal mining land instability, ground gas and historic or current landfilling operations. Most Band V sites may be underlain by artificial and, in some cases, natural ground with the potential to cause significant differential settlement.