4.1 Land quality – managing ground conditions

4.1.3 Initial Assessment – walkover survey (all sites)

To assess ground conditions, a walkover survey of the site and the surrounding area shall be undertaken by a suitable person.

A walkover survey is a direct inspection of the site and the surrounding area carried out in conjunction with the desk study. Indications of any potential hazards should provide a basis for the investigation. A photographic record of the site can help in the reporting of the walkover survey.

Table 2: Potential hazards

Source of informationItems to be taken into account
Topography• abrupt changes in slope
• valley bottoms or depressions which may be soft or filled
• evidence of overburden on slopes
• excavations at the base of the slope
• signs of landslip, eg tilting trees, posts or walls
• signs of subsidence
• evidence of imported soil including local surface depressions, tipped material or rubbish, particularly if it is hot or has an odour
Soils and rocks• the basic ground type
• evidence of peat, silt or other highly compressible material at or below the surface
• cracking or stickiness of the surface which may indicate a shrinkable sub-soil
• sudden changes in conditions, eg clay to chalk or soil to rock
Surface water and vegetation• a high water table indicated, eg by waterlogged ground
• signs of flooding
• reeds or water-loving plants
• springs, ponds, wells, ditches or streams
• the source of any discoloured water
Vegetation• vegetation which may indicate the nature of the soils
• sparse dead or dying vegetation
• type and condition of vegetation on land adjoining the site
• species, height and condition of the trees
• species, height, spread and condition of hedges and scrub on clay
• evidence of former trees, hedges or scrub on clay
Structural information• damage to structures, eg cracking in buildings, on or around the site
• other evidence of movement, eg tilting or distortion
• any structures or services below ground
Local information • local knowledge of the site, eg mining, refuse tipping or flooding
• local industrial history records indicating past and present uses of the site
• place names and street names that may give clues to previous site usage,
eg Brickfield Cottage, Water Lane, Tin Shop Hill

Last updated: 2nd January 2024

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