These FAQs may be subject to change periodically.
DoWCoP FAQs - General
Article 14 of the Waste Framework Directive requires necessary measures to be taken to ensure that waste is recovered or disposed of without endangering human health and without using processes or methods which could harm the environment, and in particular:
- without risk to water, air or soil, or to plants or animals;
- without causing a nuisance through noise or odours;
- without adversely affecting the countryside or places of special interest.
In assessing the suitability of materials (and hence waste status) one has to consider not only the circumstances in which they arise but also the circumstances in which they are to be used. When considering “Site of Origin” scenarios, an acceptable level of risk to the environment is defined in the context of the sites current/baseline condition. This enables the re-use of otherwise contaminated materials on the basis of waste minimisation; land quality is being maintained or enhanced, thus achieving the objectives of the Waste Framework Directive.
When considering the importation of foreign materials to a site it is important to ensure that the materials will be used in a way that achieves the same goals. If materials were imported to a site so that new hazards were created, or existing hazards increased the net effect would be to increase the level of risk posed to human health and the environment. This would be contrary to the objectives of the waste framework directive. It should be remembered that land-use can and does change over time meaning that any new hazards created by importation of materials will have to be dealt with in due course. The net effect is that land quality would have been degraded rather than maintained or enhanced; this is not considered sustainable.
The differential between the costs of disposal of hazardous vs. non-hazardous materials also make it attractive to criminals to undertake “sham recovery” operations whereby the development itself is secondary to the profits to be made in circumventing legal controls on disposal. By providing clear guidance in the DoWCoP regarding such matters the Environment Agency hope to dissuade its potential exploitation in this manner.
The following simple approach can be used to ensure that you do not inadvertently introduce new hazards to a receiver site OR significantly increase the hazards that are already present:
- Define the quality of the material you need at your receiver site by reference to a site specific risk assessment as normal. Remember that in order to be suitable, materials must not cause pollution or harm to human health / environment (including controlled waters) at the location where they are to be used.
- Check whether the values derived would fall above the current thresholds used for hazardous waste classification purposes.
- If any of the values are above these thresholds then alter the materials specification to limit the allowable levels of these substances to below the thresholds.
In most cases this conservative approach will be sufficient to prevent the importation and reuse of materials in a way that the Regulator may consider to be “Sham Recovery”. It should also prevent the inadvertent creation of any significant problems for any future regeneration of the site.
In the unlikely event that the concentration of some substances at the receiver site are already above the hazardous waste classification thresholds but are not posing any unacceptable risks (as demonstrated by your site specific risk assessment agreed with the regulators), then raise the issue with the Environment Agency when seeking approval for the Cluster Project. In exceptional circumstances you may be allowed to import materials with levels of substances equal to or below the levels already existing at the receiver site. To do this the Environment Agency will need to be satisfied that the proposal is not unnecessarily substituting hazardous materials for non-hazardous alternatives (i.e. Sham Recovery).
Material placed beneath buildings and hard standing such as car parks and roads within the land being developed is not waste, if the material is demonstrated to be non-waste by evidence of suitability for use and the works are carried out in accordance with the requirements of the CoP.
Where there is any dispute regarding the use of material in this way then readers are referred to the Environment Agency guidance “Defining Waste Recovery: Permanent Deposit of Waste on Land”.
Where excavated material is not suitable for the proposed use it will be waste and hence the CoP will not be applicable. For example if the material has to be placed in an engineered cell and managed to prevent harm to human health or pollution of the environment then this would be viewed as having been discarded as waste. This will be a landfill and require an environmental permit. There is a distinction between this scenario and that relating to cover layers above.
The need to distinguish between “contaminated” and “uncontaminated” soils is no longer considered necessary. These are self-defining terms on a site specific basis having regard to the risk assessment, e.g. some soil may not be considered contaminated for a given land use, but would be for a more sensitive land use, on the same site.
No it is not likely to be waste. Typical uses of recovered aggregate include pipe-bedding and selected backfill to sewer excavations; carriageway sub-base construction; and the construction of vertical, granular filled drains to aid consolidation of compressible clays.
Bentonite slurry cut-off walls: Bentonite / cement slurries are used to construct vertical barriers in the ground to prevent groundwater movement or to contain contaminants.
Depending upon the site-specific circumstances, this would either not require an Environmental permit or may comply with the EA Enforcement Prosecution Policy Functional Guidelines. Reference should be made to the EA Remediation Position Statement Guidance for details.
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 affects 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 re-cycled 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 geo-textiles 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.
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