Construction activities carried out on uncontaminated soils solely for the purpose of improving geotechnical properties are not generally regarded as waste treatment operations and do not require a permit. These include:

• Lime/Cement Stabilisation: Stabilisation of soils with high moisture content to improve their compaction characteristics by mixing with lime cement or cement only. If the lime is considered to be a waste material, or if the treatment is required specifically to recover a discarded material this may need to be reconsidered.
• Vibro Compaction: Vibratory techniques to improve the bearing capacity of weak soils (often made ground). These techniques use a vibratory poker that is lowered into the ground under its own weight. In most cases, stone is introduced into the ground either down the centre of the poker or into the hole when the poker is removed. The poker applies further compactive effort until adequate resistance is achieved. The combined effects of the vibration and the introduction of the stone result in an increase in the density of the soil and a consequent improvement in bearing capacity. This activity must be carried out in accordance with requirements of the EA published guidance "Piling and Penetrative Ground Improvement Methods on Land Affected by contamination: Guidance on Pollution Prevention. NC/99/73".
• Dynamic Compaction: This technique involves dropping a heavy weight from considerable height to compact weak soils (often made ground). A series of ‘footprints’ are formed which are subsequently filled with granular fill. This may either be a primary aggregate or a recycled material. Dynamic compaction is not a waste treatment activity (unless it is being done on a landfill site for example) and any risk to controlled waters must be addressed during the assessment of the Planning permission.
• Surcharging: This technique involves placing soils in a mound to compress weak soils thus reducing future settlement potential. If the material used for the surcharging is generated and then reused (in line with the CoP) on the site it should not require a WFD permit or Exemption. However, if the material is to be imported or exported from the site after use there may be requirements for waste permitting.
• Piling: There are various forms of piling which are used to transfer structural loads through weak soils to more competent materials at depth. These range from driven displacement, bored and continuous flight auger bored piles. A WFD permit will not be required for this activity. The piling activity must be carried out in accordance with requirements of the EA published guidance "Piling and Penetrative ground Improvement Methods on Land Affected by contamination: Guidance on Pollution Prevention. NC/99/73".
• Soil Reinforcement: This technique involves the introduction of geotextiles or ‘geogrids’ to layers of soil (often made ground) to improve load distribution and bearing capacity. This technique is also often applied to improve the slope stability of soils to facilitate construction of steep sided embankments. A variation, to improve the stability of cuttings, is the use of ‘soil nailing’ whereby rods are ‘fired’ into the ground at regular intervals.
• Reinforced Concrete Raft Foundations: This is a common foundation solution used on weak or potentially expansive soils. Certain ground conditions, in particular expansive clay soils require the foundation to be constructed on a bed of compacted granular material made from primary aggregate.

The removal of more than or equal to 20m3 /day water may require the granting of an Abstraction Licence under the Water Resources Act 1990. However, the current Environment Agency position is not to require a permit for pumping water that has gathered in an excavation if the water is to be disposed of solely to prevent interference with building operations. Any changes to this position will be publicized via the EA or DEFRA websites.

Dewatering of excavations: Where extractions have to penetrate below standing groundwater levels, dewatering will be required. A number of techniques ranging from sump pumping, to the use of external well points or deep wells can be used. Discharge of the pumped water may require a permit but the activity does not fall within the remit of the WFD.

Infiltration Drainage: Sustainable urban drainage solutions (SUDS) often call for infiltration of collected surface water to maintain surface water discharges from a developed site as closely as possible to the rates prior to development. This can occur on greenfield and brownfield sites, although we would not encourage this on contaminated sites. Discharge consents may be required but these activities do not fall within the WFD.