The end for dig and dump?
19 July 2005, News release from Leyden Kirby Associates Ltd
Dr Scott Elliott, Technical Director, Leyden Kirby Associates Ltd, looks at the implications of the Landfill Directive on the redevelopment of brownfield sites.
The 16 July 2004 was a landmark day for the future of the redevelopment of brownfield sites within the UK. This day marked the implementation of the Landfill Directive across the European Union. There are three fundamental objectives within the Landfill Directive that directly impinge on the redevelopment of Brownfield Land:
1) The end to co-disposal of hazardous and nonhazardous waste;
2) The requirement of any waste destined for disposal to land to undergo 'Basic Characterisation' and comparison against new EU-wide Waste Acceptance Criteria (WAC); and
3) The requirement for the pre-treatment of waste before entering a landfill site.
All three of these requirements are inevitably going to increase the cost of the remediation and redevelopment of brownfield sites, as well as potentially substantially increasing the time taken to complete the remediation exercises. The affect of the introduction of this directive will be widespread across the whole community of public and private landowners. In particular, it is likely to have a sizeable affect on the following:
o Developers and housebuilders with large landbanks of brownfield sites;
o Regional Development Agencies responsible for flagship schemes (eg: The Avenue Coking Works);
o Government Departments (eg: English Partnerships, MoD)
o Local Authorities who may have in their possession large tracts of brownfield land.
In addition, the multi-million-pound investment Pathfinder and Housing Market Renewal schemes, a government-led initiative, will be likely to feel the full brunt of this directive - a directive on which the government department DEFRA has been so slow to provide advice and guidance.
THE END OF LANDFILL AS WE KNOW IT
The UK practice involving the co-disposal of Non- Hazardous and Hazardous Wastes has now ceased to be legal (see sustain' Vol 5 No 3 p42). Over 200 landfill sites around the UK will no longer be able to accept hazardous waste. At present, at the time of writing less than a dozen sites in the whole of the UK had applied for licences to accept hazardous waste. Crucially, none of these sites was within London, Wales or the Midlands. This has particular strategic importance to sites such as the Thames Gateway redevelopment and the remediation of the Avenue Coking Works.
In addition, 30 non-hazardous waste sites have made applications to operate 'mono cells'. This will enable stable non-reactive hazardous wastes to be deposited within a non-hazardous landfill. However, the pre-treatment/stabilisation will have to be rigorous to meet the appropriate WAC. This will again substantially increase the cost of landfilling this waste.
At present, it is estimated that over 2.5M tonnes of hazardous waste is landfilled annually in England and Wales. Construction and demolition operations mainly associated with brownfield redevelopment are estimated to contribute over 20 per cent of this hazardous waste. It has also been estimated that 90 per cent of this material is currently disposed of using Civil Engineering techniques dominated by the 'dig and dump' approach. This simple approach to the remediation of hazardous waste arising from brownfield sites will become untenable after 16 July 2004 deadline.
CHARACTERISATION AND PRE-TREATMENT OF CONTAMINATED SOILS
All wastes destined for disposal to land require 'Basic Characterisation', also known as Level 1 Testing. (Environment Agency, 'Guidance on Sampling and Testing of Wastes to Meet Landfill Waste Acceptance Procedures (STWAP)' Dec 2003).
This 'Characterisation' testing is more onerous than current practices and likely to be more expensive. The Level 1 test will determine the properties of the waste, which in turn will define whether it will be classed as Hazardous or Non-Hazardous, once the European Waste Catalogue (EWC) code has been checked, (Environment Agency WM2, 2003).
If the waste is classified as hazardous, then the Landfill Directive gives a hierarchy of treatment objectives, which are to either:
(a) Reduce the volume of the waste; or
(b) Reduce the hazardous nature of the waste; or
(c) To facilitate the handling of the waste; or
(d) To enhance the recovery of the waste.
Having treated the waste, the person responsible for its management will be required to test the waste under Level 2 compliance testing (EA, STWAP 2003). Only then will a decision be able to be made on whether the waste can be accepted within a 'Mono-Cell' within a Non-Hazardous landfill or within the more expensive and isolated Hazardous landfill sites.
EFFECT ON THE SITE INVESTIGATION OF BROWNFIELD SITES
The evolution of compliance with the Landfill Directive and the Hazardous Wastes Directive will have a profound effect on the brownfield land industry. The time taken to prepare a basic waste characterisation for the more complex contaminated land and demolition jobs, together with the need for a much greater degree of certainty as to the variability within the wastes, will be significant. This work should ideally be performed at the same time as the contaminated-land appraisal and risk assessment Phase II investigation works.
TIME FOR FORESIGHT, GUIDANCE AND INVESTMENT
One factor that has so far been overlooked in this article has been the fantastic opportunity that the Directive offers for the development and use of insitu and ex-situ remediation techniques across the UK. The increase in gate fees at hazardous sites (currently estimated to treble in cost) means that a new generation of remedial technologies can cost-effectively compete with the soon to be unconventional method of dig and dump. However, it has to be seriously questioned whether there are enough established techniques operating in the UK with the ability to step up to the plate and adequately deal with the anticipated contaminant hazards. These techniques will need to be both proven and cost effective and have the EA's backing with a relevant mobile-plant licence. In addition, to fill the gap soon to be left by the removal of the dig-and-dump option, these techniques will also be required to deal with the contaminant hazards in a relatively short period of time.
A CLEAR, CONCISE AND SENSIBLE APPROACH
The adoption of central remediation hubs as operated in many EU countries would seem an obvious and sensible way forward. However, a recent exSite Research Ltd report (Entec UK Ltd, April 2004) on such opportunities has raised serious limitations over the implementation of such schemes, mainly because of the confusion of when the treated material ceases to become a waste.
These central remediation hubs are seen as being fundamental to the successful implementation of the landfill directive but cannot proceed without a clear, concise and sensible approach to the designation of waste following treatment of the material to acceptable standards. If this information is provided, then we should see a surge of investment from sectors such as the Landfill Operators and Remediation Contractors. This investment into the treatment techniques is considered essential to ensure that compliance with the Landfill Directive is achieved and that our brownfield sites are redeveloped in a sustainable and cost-effective manner.
Failure by DEFRA and the EA to provide this guidance and information will see many brownfield-redevelopment sites shelved across large tracts of the country. This may particularly be so in a number of strategically important regeneration areas across the UK, thus making the government target of achieving 60 per cent of new housing on brownfield land look increasingly remote.
'Technical Guidance WM2: Interpretation of the Definition & Classification of Hazardous Waste' Environment Agency (June 2003)
'Guidance on Sampling & Testing of Wastes to meet Landfill Waste Acceptance Criteria Procedures' Environment Agency (December 2003)
ExSite Research Ltd - Cluster Project: Soil Treatment Hubs for Off-site Treatment, Recovery & Re-use of Contaminated Soils (April 2004)
For further information please email Leyden Kirby Associates Ltd