The 1999 EU landfill Directive introduces new waste acceptance requirements, according to a three-level hierarchy of basic characterisation by waste producers, compliance testing by landfill operators and verification as waste arrives at the landfill. In the UK, the new rules are expected to be introduced in July 2005 at landfills for hazardous waste and on a site-by-site basis for other sites as new permits are issued between now and 2007.
All waste producers will have to obtain characterisation data to determine for which class of landfill, if any, their wastes are suitable. These data will also help in determining whether further pre-treatment is required before acceptance at a landfill.
The waste acceptance criteria were completed by a technical committee in 2002 (ENDS Report 336, pp 50-51 ). In the main, they comprise a set of limits on a waste's leachability and organic carbon content.
Last year, the Government consulted on draft regulations to apply the criteria in the UK, but the consultation left many critical issues up in the air (ENDS Report 345, pp 44-45 ). In particular, Ministers have yet to decide whether to take advantage of the option to allow weaker acceptance criteria to apply at certain landfills where site-specific assessments indicate that there would be no risk to groundwater.
In its new guidance, issued for consultation in January, the Agency says that most waste types will require some testing to determine the relevant properties. The exceptions will be wastes for which a comprehensive dataset already exists, and those for which the composition may be predicted from a knowledge of the process producing the waste.
The Agency will also compile a list of certain non-hazardous wastes - such as municipal solid waste - for which no testing will be required.
While recognising the commercial sensitivities, the Agency recommends a partnership approach between waste producers and contractors to encourage the free exchange of data on waste characterisation. "The exercise will be made easier in the context of reliable, publicly available data on generic waste streams."
The guidance also stresses that there will be benefits to those who collect reliable data "well ahead" of the introduction of the full EU criteria in July 2005. For example, if the analysis indicates that wastes are borderline, or that hazardous waste limits are being exceeded, there may be time to modify the production process or waste handling.
Conversely, "a waste producer with little knowledge of the characteristics of his waste, who has invested in only the bare minimum of testing, may be faced with limited or no landfill disposal options," the Agency warns, "should routine compliance monitoring conducted by the landfill operator indicate even occasional failure."
It will be important to gain an understanding of the variability of a particular waste stream, and the factors contributing to the variability, so as not to be caught unawares.
The document underlines that it is the waste producer, rather than the contractor, who is likely to be best placed to understand the scope for variability of the waste stream. Factors include the quality of feedstock, cyclical operations, shut downs and shift changes and sampling scale.
Where a waste producer wishes his waste - or waste from a range of similar plants - to be included on a national list of wastes requiring a reduced level of testing, a detailed set of characterisation data will be required, covering all the points in the operational cycle.
The Agency says there is an opportunity for trade associations to set up structured programmes of testing in sectors producing generic industrial waste streams, such as slags, foundry sands, incineration residues, coal-fired power generation residues or water utility waste streams. The costs can then be shared.
The operator of the treatment process will have to follow the same approach to information gathering as the primary waste producer. A full characterisation of the treated wastes will be needed to demonstrate suitability for landfill acceptance.
In addition, the inherent variability of the process will need to be established with respect to process inputs and operating condition. Where the treatment plant is located at a third party site, there will be an even greater need for reliable data on the quality and consistency of the treated waste, says the Agency.
In same cases, the treatment operator may be looking for treatment methods to remove hazard characteristics so as to render the waste "non-hazardous". Alternatively, the site chemist might be seeking to render the material stable and non-reactive - in line with the waste acceptance criteria for hazardous cells within non-hazardous landfills.
An advantage of using treatment plants belonging to the landfill operator is that there is more likely to be a free exchange of information between the two.
An operator's primary responsibility will be to test compliance with the acceptance criteria for his landfill. "He will be looking particularly for assurance that there will be no appreciable hot spots - abnormal or unusual runs/batches/episodes in the production process - which might generate wastes that would fail the test," the Agency says.
The surest way of gaining such assurance is by seeing all relevant findings from the producer's characterisation programme. The Agency will also require the landfill operator to provide an annual compliance report, to be copied to the waste producer.
But there is no legal obligation on the waste producer to share his data and process knowledge with the waste contractor. The Agency issues a plea for cooperation at this juncture: "It would be most cost-effective for both the waste producer and landfill operator to view the data collection as a partnership and share the information, as far as is commercially possible."
Where the landfill operator receives no characterisation data, he will probably have to commission testing on behalf of the waste producer and include the costs in the disposal charges. Where there is no evidence on a waste stream's consistency, the landfill operator will seek assurances that data do not overlook worst-case situations.
In general, landfill operators are recommended to adopt a targeted worst-case approach to sampling, focusing on circumstances where limits are most likely to be breached. It will be necessary to have information from the top-level work on waste characterisation so as to understand the factors affecting waste quality.
The guidance includes a model to help operators understand the statistical power of their sampling programmes. A minimum of six targeted samples per year will generally be required for each waste stream.
Where there is good reason to believe that a waste stream is homogeneous over time, it may be possible to pursue random or representative sampling instead of targeted worst-case sampling. It may then be possible to justify scaling back the testing parameters and frequency.
However, where a particular consignment is found to be non-compliant, it means that the whole year's waste from that producer will be deemed to have failed. It may be necessary to ban the waste from the site. Alternatively, the producer might be required to undertake a new characterisation exercise, with greater emphasis on identifying the factors leading to variability or hot spots.
Landfill operators will face an obligation to inform the waste producer of any failures, and the producer will be required to explain the reasons for the failure and how he is going to prevent a recurrence.
"If the waste producer is unable to provide this information, any further consignments of the waste should be refused." The Agency will also require landfill operators to make regular returns on compliance monitoring. "Repeated failure will lead to enforcement action."
The lowest tier of the waste testing procedure is on-site verification, consisting of a visual inspection of each load delivered to the landfill before and after unloading, together with document checks. The guidance says that visual checks prior to unloading will not be required where the waste is not accessible. For wastes deposited at landfill sites operated by waste producers, verification can take place at the point of dispatch.