Controlled Waste For Landfill

Marjorie Bark and Steve Penn of Applied Environmental Research Centre Ltd review the regulatory issues affecting the use of inert waste in quarry restoration

Recent changes in legislation affect the use of both on-site and imported materials in the restoration of mineral workings. Inert waste has frequently been used as a source of fill material in the restoration of quarries to the original topographic profile. This has provided an economic and effective material for this purpose but many types of material historically used for restoration are now classified as waste. The use of waste is subject to a series of regulations designed to protect the environment from the potential pollution caused by waste disposal. Waste activities are regulated according to the level of environmental protection required to prevent harm to the environment, which is usually dependant on the form and content of the waste involved and whether it is defined as inert, non-hazardous or hazardous. Inert wastes are defined as those wastes that are biologically, chemically and physically inactive and comprise waste concrete, bricks, soil and stones, and ceramics among other similar materials.

There have been three important changes in waste-management regulation in recent years that affect the restoration of quarries using inert wastes:

• The introduction of the PPC regime to inert landfill sites has increased the level of regulatory pressure for quarries that are large or complex enough to meet the PPC criteria.
• The tightening of the registration process for exemptions from waste-management licensing now excludes them as an option for many quarry restoration projects.
• Under the Waste Management Licensing Regulations 2006¹, quarry and mining by-products are ‘controlled wastes’. Consequently, they have become subject to the requirements of the EU Waste Framework Directive in line with other commercial and industrial wastes. This means that the management of such materials must comply with the ‘duty of care’ regime, waste carrier registration and the appropriate site licence of permit.

Unnecessary regulatory burdens and delays can be avoided if site operators are certain about the type of activity that they intend to operate and, importantly, are capable of demonstrating that the use of inert waste will not have an adverse effect on the environment. Quarry activities are a significant source of inert waste in the form of process residues, overburden, interburden and silt from gravel washing. These inert wastes are used as a readily available source of restoration fill.

Site operators using inert materials (not inert waste) for restoration work must be able to demonstrate that the material was produced for use in restoration and cannot be classified as waste. The definition of waste and non-waste has generated a lot of legal activity and is a separate subject for discussion. Any uncertainty over the categorization of a material as waste or non-waste should be clarified though professional or legal advice.

USE OF INERT WASTE FOR RESTORATION

The use of waste for quarry restoration is a technically and commercially well established activity to re-establish a profile similar to that of the land prior to development. Planning permissions for quarries often contain a condition for full profile restoration before the expiry of the planning consent. Waste materials can be used to fill the void space left by quarries, and a certain level of revenue can be generated from the waste-management activities. There are also monitoring and aftercare costs because of the risk of pollution from the use of waste, and all waste-management activities require some degree of regulatory inspection, which incurs charges from the Environment Agency (EA). The restoration of quarries using waste is categorized as either:

• landfill – where waste is used to fill a void and the properties of the waste are irrelevant to this purpose; this is a ‘disposal’ operation
• landspreading – where the waste is used because it has beneficial properties; this is a ‘recovery’ operation.

Both the use of landfill and landspreading activities for quarry restoration have been subject to the recent changes to waste-management regulations.

If a site is to use inert waste, there are three options for regulatory control:

• Exemptions from waste management licensing – which are permitted for waste activities that are too small, temporary or innocuous to require licensing under the EU Waste Framework Directive
• Waste Management Licensing – which implements the environmental protection measures for all waste storage, treatment and recovery activities under the Waste Framework Directive
• Pollution and Prevention Control (PPC) – which implements the environmental protection measures for landfill activities under the EU IPPC and Landfill Directives.

All waste activities in England and Wales are regulated by the EA. All operational landfill sites are regulated under the Pollution and Prevention Control (PPC) permitting system. Older, non-operational landfills are still regulated under the waste-management licensing regime, as are ‘landfill for recovery’ operations, where the filling of a void space can be classified as a recovery operation. Landspreading activities are covered by exemptions from Waste Management Licensing if the operator can demonstrate that the waste provides a benefit to agriculture or ecological improvement.

Determining which permit or licence is required for a site can often involve detailed discussions with the EA where both sides have to seek technical, or even legal, advice. Table 1 summarizes the criteria for each regulatory mechanism that relate to the use of inert waste in quarry restoration.

The purpose of the waste-management regulatory system is to allow the regulatory bodies to maintain fair and proportional regulation of all waste-management activities.

The regulator charges fees to recover the cost of inspecting and administering each site in accordance with the ‘polluter pays principle’. Operators of sites with complex environmental or operational issues are subject to higher costs because of the level of regulatory effort. Similarly, those sites with a negligible environmental impact incur lower charges and are inspected less frequently. Under the Waste Management Licensing system, exemptions were created to exclude the activities that were small, innocuous or temporary from applying for a waste-management licence. Operators did not incur any costs from the EA because of the benefit to agriculture or ecological improvement provided by landspreading activities.

Application of the regulatory options

All three types of regulatory control for waste-management facilities are subject to the requirements of Article 4 of the Waste Framework Directive 91/156/EC, which states that waste is recovered or disposed of without causing pollution, harm to human health or adversely affecting the countryside. The type of regulatory control required for a quarry restoration operation depends on the level of control required to protect the environment. The regulatory mechanism for environmental protection may not be reflected in the planning consent for a site. Some planning permissions may differentiate between landfill and restoration as two types of activity. The EA will make a determination of landfill, recovery and landspreading based on their own assessment of the proposed waste activities rather than referring to the planning permission.

WASTE-MANAGEMENT LICENSING AND ITS EXEMPTIONS

There are two regulatory options for the use of inert waste within the Waste Management Licensing system, licences and exemptions.

Exemptions

Waste Management Licensing Regulations 1994² contains a schedule of exemptions. Before October 2005, there were three exemptions relating to spreading waste on land, one of which, paragraph 9, permitted the spreading of waste to benefit agriculture or ecological improvement, which could be applied to quarry restoration. The exemptions were free, rarely inspected by the EA and never expired. In the late 1990s the national press reported allegations from within the waste industry that exemptions were being abused by operators of ‘cheap disposal’ or ‘sham recovery’ sites that had the same potential to cause environmental harm as landfill activities ³.

The system has been reformed through the Waste Management Licensing Regulations 2005 ⁴ to reduce the opportunities to abuse the exemptions, and there is now a charging scheme and an application process for exemptions. Exemptions under paragraph 9A expire after 12 months (although they can be renewed), and a fee is due to the EA with each application and renewal.

The application process for exemptions is now more stringent. Under paragraph 9A, the applicant has to provide evidence of the benefit to agriculture and ecological improvement through laboratory analysis and a certificate submitted with the application. There are also strict limits on the spreading of waste. In particular, the waste cannot be used to raise the level of the land and deposits must be less than 2m deep at any cross section of the site and cannot exceed 20,000m³ per hectare. It is still possible to register a paragraph 9A exemption for a quarry restoration process if the restoration meets the relevant criteria, although the criteria are more likely to exclude quarry restoration activities because of restrictions on the waste depth and proximity to environmentally sensitive areas.

Licences

The other option under the Waste Management Licensing system is to apply for a waste-management licence for a recovery operation. Restoration activities can be described as recovery operations (rather than waste disposal) if there is a demonstrable link between the use of waste for restoration and replacing the need for a particular raw material. For example, using imported overburden where there is a benefit to use imported inert waste for restoration rather than non-mineral, on-site materials.

POLLUTION PREVENTION AND CONTROL

The PPC regime has three classifications for landfills according to the type of waste disposed at the site. Inert waste landfills are restricted to only accepting wastes that are chemically, biologically and physically inactive, and will therefore pose the lowest risk of pollution. Non-hazardous and hazardous sites are required to maintain site engineering and additional infrastructure to control, contain and treat the potentially polluting leachates and landfill gas created from the waste pile.

If a quarry restoration project involves a landfill operation, the operator has to apply for a PPC permit. The cost of maintaining a PPC permit includes the provision for engineering controls, maintenance of management systems and waste-acceptance procedures, environmental monitoring, landfill restoration and aftercare.

For a quarry restoration activity to be excluded from the requirements of the PPC regime, the site operator has to produce evidence that the restoration activity is ‘landspreading’, not a ‘landfill’. Paragraph 4(b) of the Landfill Regulations 2002 excludes ‘the use of suitable inert waste for redevelopment, restoration and filling-in work or for construction purposes’ from the definition of landfill.

CONCLUSION

Activities that involve the use of inert waste to restore a quarry to its original profile are either landspreading or landfill activities. Quarry restoration as ‘landfill’ or ‘landspreading’ will incur some form of regulation by the EA and therefore requires careful design to control the financial impact. The level of regulation depends on potential environmental costs and benefits of the use of inert waste.

Discussions with the EA may not be consistent with the terminology used by other regulatory bodies such as local planning authorities. As a regulator of the waste industry and having a responsibility to protect groundwater, the EA make decisions based on their own assessments of the type of activity and its potential benefits and costs.

All types of regulation have associated costs and benefits to quarry operators. The use of PPC permits, waste-management licences or exemptions are designed to reflect the potential environmental impacts of the restoration projects and have different implications for costs and restoration designs. Operators need to consider the potential effects of using inert waste for quarry restoration projects, if they are to avoid unnecessary inconvenience or delay to their projects.

References

1. Waste Management Licensing Regulations 2006, HMSO SI.937
2. Waste Management Licensing Regulations 1994, HMSO SI.1056
3. FEARY, M. et al: ‘Pollution Concerns Associated with Disposal Options Exemptions from the UK Waste Management Licensing System’, Proceedings of the 9th EngD Conference in Environmental Technology, University of Surrey, January 2002
4. Waste Management Licensing Regulations 2005, HMSO SI.894

Applied Environmental Research Centre Ltd, Tey Grove, Elm Lane, Feering, Colchester, Essex CO5 9ES; tel: (01376) 572582; fax: (01376) 572700