Frequently Asked Questions - DoW:CoP General Questions

Yes - See section A3.3 Fixed Soil Treatment Facilities of the Version 2 of the DoW CoP.

Potentially: The Pulverised Fuel Ash would have to constitute made-ground and be excavated and re-used as earthworks materials as part of a defined Hub and Cluster development. However the filling of mineral voids is commonly regarded by the Environment Agency as a landfilling activity which would rule out the use of the DoW CoP.

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:

1. 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.
2. Check whether the values derived would fall above the current thresholds used for hazardous waste classification purposes.
3. 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.

In certain DoW CoP scenarios liaison with the regulators is either required or the most appropriate option. This liaison DOES NOT require the EA or NRW officers to assess / read / approve MMPs. It provides an opportunity for projects to flag the sites intentions to use the DoW CoP and for the regulators to share any concerns they have about the site, operator or neighbourhood.

For reuse on Site of Origin of non-naturally occurring materials the EA / NRW do their responses through the normal planning matrix process on reports, remediation strategies etc. EA / NRW Waste teams and / or GWCL teams should just check, if treatment is involved, that a MTP is deployed appropriately.

EA / NRW Waste officers do not always require consultation for direct transfers of clean naturally occurring materials between two sites, if there is a clearly referenced desk study or site investigation report which confirms the site has no previous contamination issues. The QP is required to review and confirm this by providing the document reference in the Declaration.

Consultation is required for Cluster projects to agree the donor sites and receivers sites ahead of any transfers. This is just agreeing the sites, location  and timeframes NOT the MMPs. The regulators may ask to see MMPs if they so wish.

Our work starts as soon as a declaration is submitted and therefore we do not offer refunds for cancelled declarations.

Yes, with additional requirements: Golf course Receiver sites present a unique challenge for the DoW CoP. This is due to the typically large volumes reused, long project durations, and subjective course design which can result in questionable volume requirements.  Following concerns raised by the Environment Agency / Natural Resources Wales, golf course projects will now be subject to additional checks during the Declaration preparation and submission stage and at Verification report submission.

The project team will be required to have notified the local Environment Agency / Natural Resources Wales waste team of their intent to use DoW CoP for the import of clean, naturally occurring soils, and have allowed 21 days for comment. This is therefore different to other projects using Direct Transfers, which operate on the usual liaison requirement confirmed in Table 2 of the DoW CoP (page 20). The Qualified Person (QP) must review the regulator correspondence and reference this in the Declaration. The Declaration short name should clearly reference the golf course end use. Further, the project team must ensure the Environment Agency / Natural Resources Wales waste team is updated on the project importation progression every 12 months.

During the review of these types of Declaration, CL:AIRE might engage with the regulator and additional processing time should be expected. Therefore, please allow 10 days for the issue of these Declaration Receipts.

These checks have been brought due to some poor performing sites which have:

• not been fully tracking materials imports;
• had discrepancies in Donor site records;
• had material volumes and type not compliant with the original Materials Management Plan specification; or
• included materials that are not clean naturally occurring materials.

It is hoped that this review process and future developments will ensure good practice, as required for use of the DoW CoP, and enables golf course projects to continue making use of the scheme to reuse suitable materials for these types of engineering earthworks.

Colliery waste materials generated subsequent to the Mining Waste Directive (MWD) (2006) are outside the scope of the DoW CoP (see paragraph 1.11 of the DoW CoP).  Historically generated materials are not covered by the MWD and may also fall outside use under the DoW CoP.  It is generally the case that materials termed colliery spoil[1] can include overburden and mixed geology excavated as a part of the process of winning coal.  Colliery spoil can also include coal processing wastes which may have been placed on the site of origin or on nearby sites as backfill after the mining process was completed. 

Certain materials associated with collieries might be eligible for reuse under the DoW CoP:

• overlying soil materials;
• where the colliery spoil forms a minor component of the soil and stones materials that are to be reused, and the materials are otherwise within the scope of the DoW CoP;
• materials on the colliery site that are simply an overlying natural bedrock with no coal materials.

Agreement with the Environment Agency or Natural Resources Wales must be sought in a recognised customer engagement process and full requirements of the DoW CoP must be met. If formal responses are not received from engagement within 21 days, then under published customer engagement policies it can be assumed there is no objection to the specific materials reuse if the engineering works are also approved formally under the planning regime.

Where colliery spoil heaps pose a serious risk to the environment or human health due to instability, a reprofiling of materials may be required to reduce the stability risks. The mechanism to achieve reprofiling may include DoWCoP reuse of spoil materials on site of origin approach where this is agreed formally with the relevant regulator in writing.

[1] Colliery spoil is a colloquial term which refers to the materials in the sedimentary strata that are associated with the coal seam, but which are not the coal seams themselves, or are generated by processing the coal, i.e., burnt shale.  Spoil on colliery sites (like many other naturally occurring geologic materials exposed to the environment) can include heavy metals and other contaminants that can be harmful to human health and the environment, including animals and flora making it unsuitable for certain uses. Combustible materials, which may be present, such as coal and other organic matter can, via a process of oxidation and heating, lead to spontaneous combustion and underground fires. 

Colliery spoil materials can also be subject to erosion and instability, especially if it is not properly managed or stabilised.  

Whether soil stockpiles can be used under DoW CoP is an issue that is frequently raised by users and regulators. Who decides the correct approach is sometimes difficult to determine, but it is easier if one always comes back to the “is it waste?” question and then thereafter what available routes can be followed.

Waste is something that a holder of a material discards, intends to discard or is required to discard. So, stockpiling materials should be looked at in that context.

Examples of Poor Practice

If a site is discarding materials from the outset, the materials are likely to be deemed waste. An example would be a project which plans to carry out excavations to create a basement for a new development. The site is tight for space and there has been no forward plan to find an option to reuse the material anywhere in the project timeframe. The holder just wants the material off-site after the initial excavation and stockpiling at the loading area. This is an indication it is being discarded, so this material is waste and must go, via an authorised waste carrier, to a permitted site. Alternatively, if it is only a small quantity and it meets the requirements it could go to a site with a registered exemption. This material / waste must be removed under the Duty of Care.

If there has been no plan in the project design stage to identify material which could be beneficially used elsewhere, and the material surplus to site requirements is temporarily stockpiled during works ready to be removed from site at the end of excavation works, then there is an apparent intention to discard and hence it is a waste.

The above two examples could be deemed poor practice in material management. The waste hierarchy has not been fully, or properly considered, and excavated material has been stockpiled with no effort to find an option to recover, or reuse the materials excavated. It is being discarded and sent off-site to get it out the way and the project is paying to have it removed.

If material is excavated and there are unexpected issues associated with it (i.e., it has unexpected contamination or poor geotechnical properties), and it is temporarily stockpiled, but the planning requirements or regulatory advice states it must be removed from site, then there is a requirement to remove the material and it is waste and should be treated as such and removed by a registered carrier to a permitted site. It is required to be discarded.

Examples of Good Practice

However, good project management and a genuine intention to have regard to the waste hierarchy from project outset can position the material in a different light. The key issue is “intention.”

A project demonstrating intention not to discard is likely to have several lines of evidence to support this claim. For example, at the design stage, a site excavated Materials Management Plan (MMP) would be in place. This would be informed by a good desk study, site sampling and risk assessment process. Prior to any excavation, the volume and type of materials to be excavated will be known. The site design strategy and MMP document will clearly state the intention to find a way to reuse or recover all the excavated materials.

In this case if material is stockpiled after excavation and stockpiles are managed in accordance with good site practice then this material can be held on site for up to 12 months. The material may be surplus to Site of Origin requirements, but there is not an intention to discard it, as clearly demonstrated in the MMP. A further line of evidence may be that the materials have been registered on the CL:AIRE Register of Materials. When a Receiver Site is identified for this material, it can be moved off-site to the nominated Receiver Site under DoW CoP. Alternative reuse options could also be as waste materials to an exempt site, providing it meets the exemption criteria, or a permitted recovery site.

Clear lines of evidence are required showing how much material will be excavated, what type of material it is, stockpile management so as not to cause any problems (runoff, dust, eyesore etc.) and where it is intended to go. A genuine attempt to identify potential Receiver Sites must be made before excavation and stockpiling. If Receiver Sites are not identified for all the material, this may not be a fundamental problem, providing all lines of evidence regarding intentions are present and efforts to find Receiver Sites can be clearly shown.  The above may also be required under planning in a Construction Environment Management Plan (CEMP).

It is important to note that material stockpiled with an intention to find a Receiver Site for beneficial reuse in this way can only be stockpiled for up to 12 months, under the relevant exemption for storage of material at site of production. Storage for longer may require a waste storage permit, or at the very least formal confirmation from the regulator of an agreed extended period beyond 12 months. This will only be a limited extension, but the maximum for larger projects may be up to three years if the material is intended for reuse or recovery.

Any material stored for longer than 12 months in a stockpile, where there is no clear intention stated to reuse, is likely to be considered waste and must be removed from site under Duty of Care to a registered waste recovery or disposal site. This material is not to be accepted at a DoW CoP Receiver Site and QPs must not sign Declarations that include such material.

Stockpiles at Receiver Sites

The above considerations also apply to stockpiles at Receiver Sites. If material is imported under the DoW CoP and stockpiled, but not used within 12 months, or in a time period agreed with the regulator, it will be considered waste and any subsequent material reuse may require a waste permit for recovery or disposal, or else the material must be removed from site as waste.

The key issue is whether there is an intention to discard, either deliberately, or by default. For example, if a multiphase project has surplus soil arisings on phase 1 and they are stored with intention to be reused under phase 3, but after 12 months they have not been transferred or used, it can be considered abandoned and potentially an illegal waste deposit.

Potentially this material, if covered by a soil stockpile management strategy, may be stored for longer with agreement from the regulators, either on phase 1 or even phase 3, but there must be clear intention for reuse and the materials must be kept suitable for reuse by good stockpile management. Any potential for them to be deemed abandoned by regulators could result in material becoming waste which could result in penalties incurred for an illegal deposit of waste. Such deposits may also be subject to landfill tax penalties and charges.

Recommendations

Good document management is imperative, with high quality and full lines of evidence, relevant agreements with the regulators, and compliance with all good practice guidance and regulatory requirements. There must be ongoing oversight, along with good materials tracking systems.

Conversely, ad hoc material management, stockpiling with no clear intentions, last minute arrangements for material transport and poor attention to timelines and project management will restrict options for material reuse and disapply options like DoW CoP, with possible enforcement actions applied to abandoned or illegally deposited materials.

The principles from which Watch Point 15 (on page 31 of DoW CoP) are derived apply to all projects using the DoW CoP, so it is important to understand what information is required to ensure it is complied with.

Although often discussed in the context of Cluster sites using brownfield soils, Watch Point 15 is equally relevant to Direct Transfer projects. The reuse of materials with naturally occurring contamination needs to be assessed and properly understood under Direct Transfer projects.

Watch Point 15 derives from the Waste Framework Directive (WFD) principles that sites must not be further degraded (in relation to Human Health and/or the environment) by import and reuse activities at Receiver site(s).

Watch Point 15 therefore requires transfer projects (e.g. Cluster and Direct Transfer) to not just assess materials being moved and establish their contaminant profile, or the potential presence of greenfield contaminants such as recalcitrant pesticides. It also requires a baseline understanding of the current status of the Receiver site. As confirmed in the DoW CoP training, naturally occurring contaminants taken from one setting to another can have significant impacts on sensitive Receiver site settings if not properly characterised and understood. This means some level of environmental sampling is required to understand the baseline at the Receiver site and compare this against any import materials test results. The level of testing will depend on soil type and homogeneity within the excavated materials at Donor sites and at the Receiver site deposit areas.

It is not acceptable under the WFD requirement to say that the imported material meets a relevant land use criteria and so is acceptable. Watch Point 15 requires that no degradation occurs to land quality. This means it is not just about risk-based criteria for the Receiver site, it is about benchmarking against the natural site baseline and any discrepancy over that in proposed import materials. Using site-specific risk-based criteria is appropriate for the Site of Origin context, for either anthropogenic or naturally occurring contamination. However, for material transfers to third party sites, the Receiver site baseline must also be used as a relevant benchmark to set import criteria. See diagram below for Watch Point 15 contaminant levels, as shown in the DoW CoP training.

Imported materials must also have regard to source mass as causing an increase in the mass source term at the Receiver site would result in an overall degradation of the site conditions.

No new contamination can be introduced to a Receiver site. This may be especially important for Donor sites with potential emerging contaminants of concern, which may not have previously been part of standard testing suites, such as materials from areas of grassland i.e. airports grounds or fire station premises, which may have been impacted by firefighting runoff.

Therefore Qualified Persons must ensure where materials are transferred, including those using Direct Transfers from greenfield sites, that projects have a proper understanding of Watch Point 15 requirements. Baseline assessment of Receiver sites must be presented as well as appropriate risk assessment to provide a control for any imports.

Whether the DoW CoP can or cannot be used to backfill quarries is a question that must be considered on the specifics of any proposed backfill operation.

As outlined in the Definition of Waste Code of Practice Training, generally, for activities involving the backfill of quarries, it is unlikely the DoW CoP will be the right mechanism to deposit materials to restore the land to original pre-extraction levels (especially in large volumes). This will generally be determined in the first instance by the planning permission originally granted, i.e. many planning permissions for mineral extraction and related activities are applied using minerals and waste planning local plans. These often stipulate where mineral workings are available and restoration of these sites should use waste materials to backfill voids under a relevant landfill permit.

Where large voids will require significant high volumes of potentially mixed wastes, and the long-term impacts of infill should be monitored due to the hydrogeological setting, it is right that an environmental permit, with its protective engineering requirements and monitoring should be employed to cover backfill activities.

The permitting approach also enables commercial arrangements to be brought into play to cover some of these engineering and monitoring costs. Planning requirements and consultation responses to the planning application process will often make it clear that a landfill for waste is to be the suitable management route for quarry backfill activities. In such cases, an Environmental Permit for Recovery or Disposal is required from the relevant regulator. Therefore the parameters of a granted planning permission for the mineral site and subsequent backfill activity are key, as well as consideration of planning consultation responses from the relevant regulator.

However, there may be some backfill activities in old mineral workings that are able to use the DoW CoP for limited materials placement activities, such as the following:

·         where the overall void is not being infilled but cut and fill activities are being used to re-landscape the quarry floor profile to create relevant future use settings.

·         hard development such as warehousing, business estates, shopping centres and similar construction projects.

·         low-level restoration to form habitat creation schemes such as scrapes, lakes, ponds, and wetlands, or for different mosaic soil conditions for biodiversity net gain for instance.

·         the creation of sandy banks for bird nesting sites perhaps to enhance existing cliff faces, or to create more safe, stable landforms.

·         engineering works to stabilise dangerous cliffs, with toe base deposits to support unstable slopes. 

These engineering activities should be carried out under a relevant planning permission for the stated purpose, and may be within the scope of the DoW CoP, providing all the other requirements of the Code are met in full.

The activity must not be a fee-earning deposit activity carried out to enable disposal of waste materials from other sites, that are discarding surplus materials, even if those materials are inert soils and stones.

So, for quarry backfill projects, it is critical that the relevant planning permission frame is understood. The scale of activity must be appropriate, and the relevant consultees must have given approval before any project uses a DoW CoP approach to undertake limited backfill activities in a quarry site setting. Where DoW CoP can be used in principle, all the requirements of the Code must be met in full, and the project managed to achieve the stated aims under the granted planning consent for limited backfill activity.

Published 27 Jun 2024

This can include the area covered:
• By a specific Planning Permission red line boundary.
• By a single detailed Remediation Strategy / detailed Design Statement.
• By an agreed Environmental Permit Deployment Form.
• Other, as agreed with the relevant waste regulators e.g. separate sites close to each other assembled to form a single development scheme , undertaken by the same developer. Agreement with the relevant regulator means this must be evidenced, even if separate parcels of land, or phases of the development are falling under Route B transfers of clean naturally occurring materials.

To align with good practice demanded by the DoW CoP, decisions about defining the Site of Origin for a specific development need to ensure sustainable solutions are achieved in any remediation or earthworks. This can be done by taking into account the principles of the Sustainable Remediation Forum – UK (SuRF-UK) i.e., environmental, social and economic principles, and more generally the Circular Economy aims and objectives for construction activities. Decisions can be guided by what is covered in any overarching outline planning permission for the specific development in question. Consideration should also be given to the Aims & Objectives of the Waste Framework Directive, e.g. the protection of human health and the environment. As the size of the Site of Origin increases, it follows that the risk of undermining this objective can also increase.

For instance, on a long linear project, it may be sensible to separate the site into different sites of origin based on; environmental sensitivities or coherency, contractual arrangements, geographic/geological units, the presence of contamination (anthropogenic or naturally occurring) of different parcels of land, or the timing of work packages . This is similar to the principle for determining how many MMPs are required for a specific large-scale project. Sites where substantive distances are involved for transporting materials between donor and receiver areas are usually better managed under Direct Transfer or Hub and Cluster arrangements unless it can be argued effectively that the alternative is the more sustainable option.

The MMP and Declaration should clearly identify how the Site of Origin has been decided if more than one area, phase, or site is included in a Site of Origin scenario, as outlined above.

Published 27 Jun 2024