LEACHATE TREATMENT IN THE UNITED
KINGDOM & OVERSEAS
During the last 4 or 5 years, the UK waste management industry has been undergoing a substantial reorganisation, as both the large PLCs, and smaller private waste disposal companies have been repositioning themselves in the marketplace to address the many changes imposed by the EU Landfill Directive, and the PPC Regulations etc.
This has resulted in a situation where, after a period of uncertainty, and lack of investment in landfill operations, organisations are now seriously addressing their problem landfill sites and their new landfill developments. This has had an influence on the demand for leachate treatment technologies, which has grown substantially during the last few years.
Another step up in demand, and treatment plant capability, is anticipated in preparation for the August 2006 deadline after which date, all Leachate Treatment Plants above a stated throughput (normally 50 tpd for non-hazardous effluents) will be required to be permitted.
The market for such treatment technology has been characterised recently by the entry of companies who bring to it heavily marketed proprietary systems, which while derived from other effluent treatment and industries, often have no track record of application to landfill leachate.
Knowledgeable and independent advice for selection of appropriate technologies at specific sties has been in short supply.
A common scenario is the release of tender documents asking for "design and build" solutions, which have resulted in submission of schemes based on a whole range of systems (for example; aerobic biological, anaerobic, reverse osmosis, ammonia stripping etc), and combinations of such technologies. The result is that clients commissioning these scheme have, on the return of the tenders, found themselves unable to make an informed choice between wisely differing technologies.
In several instances systems which been adopted as a result have not provided a complete solution, and in some cases there have been failure to comply with process requirements.
In certain other countries, such as the United States, Germany and the Netherlands, much more money has routinely been spent on purchase of leachate systems, although fundamentally there is probably far more expertise and experience available in the UK regarding landfill science and leachate treatment than in any of these countries.
General levels of landfill control in some countries are regularly overstated - for example, in the United States, far from all landfills having sophisticated double liner systems and monitoring, only a dozen years ago less than half of all waste disposal sites even had licences.
Of vital importance to selection of leachate treatment systems is basic understanding of leachate quality at landfills. Unlike other effluent streams, this can vary in all the following respects:-
in quantity: seasonally, and over time; in quality: seasonally, and over time - and not only due to dilution factors, but also with the balance of different chemicals also changing as the wastes progressively decompose.
Research funded by the UK DoE, and by specific waste disposal companies, has added considerably to our knowledge in these areas (eg: Robinson & Lucas, 1985; Robinson, 1989). A major review contract completed for the DoE by Aspinwall (just prior to the creation of Enviros from the merger of 4 consultancies), and in this we co-ordinated a mass of leachate quality monitoring information from UK landfills (over 5,000 samples), and the resulting report was published during 1996 by the Environment Agency (Robinson, 1996a). This has added considerably to knowledge in this area, and provide much-needed assistance in improved design of leachate treatment systems, especially where these have to be specified and constructed in advance of waste disposal operations at new landfill sites.
Call, or contact, Howard Robinson at the telephone number, or email address, below.
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