Landfilling of Waste

Annex A: Multi-level Test Programme for the Assessment of Waste for Landfills

This Annex contains a review of the methods necessary for the testing of a given type of waste at levels 1, 2 or 3 in relation to the acceptance criteria for waste categories I-III as listed in sect. 4.3 of these Guidelines.

Reference is otherwise made to the Danish Environmental Protection Agency’s working report "Characterisation of Waste", which is due to be published in 1997.

A.1 Sampling

If a test of the waste implies the drawing of a sample, the same procedure is to be followed - regardless of the level at which the test is being performed.

Until a proper standard method for the drawing of samples of solid waste is available within the framework of CEN, the following provisional procedures should be followed.

Homogeneous waste

"Homogeneous waste" means solid waste the composition of which is uniform throughout the waste matrix as determined by visual inspection.

Samples of homogeneous waste are taken by drawing four times the quantity of waste necessary to complete the test (subject, however, to a minimum of 1 kg). This sample is drawn and shredded in accordance with the principles in ISO 8213-1986 (E).

Heterogeneous waste

"Heterogeneous waste" means all waste that cannot be characterised as homogeneous.

Samples of heterogeneous waste are taken by drawing a representative sample - wherever this is practicable. Parts of the sample that are too large to test and whose identity and properties are known are separated (but are weighed and included in the description of the sample). The rest of the sample is shredded.

Twelve times the quantity of waste necessary to complete the test are drawn (subject, however, to a minimum of 3 kg). Otherwise the sampling procedure is carried out in accordance with the principles in ISO 8213-1986 (E).

A.2 Test programme

For each of waste categories I-III the test programme consists of three test levels. The choice of the necessary level depends on the advance knowledge of the type of waste to be assessed.

Below is a listing of the extent of the test levels for categories I-III followed by proposals for the use of test methods.

A large part of the test methods are being standardised within the framework of CEN and NORDTEST, respectively. The test methods proposed in this Annex will therefore be amended when the standardisation is complete.

Depending on the advance knowledge of the type of waste to be landfilled in a landfill unit for inert waste, the following levels should be used:

Acceptance on the positive list

For waste desired to be accepted on the positive list for Category I, a characterisation test of the waste must be carried out. The characterisation test must include all the surveys I.1 - I.7 (cf. the following section on test methods) and be assessed in relation to the requirements applying to Category I waste.

Periodical documentation

To substantiate that a type of waste corresponds to a type of waste on the positive list for Category I, an acceptance test must be carried out regularly. Acceptance tests include I.1, I.2 and I.6 (cf. the following section on test methods). For waste received regularly from the same source, the interval between tests could be fixed as 12 months.

Routine investigation

For all loads of waste received at a landfill an identification test must be performed. This test may consist of a visual inspection of the waste. In special cases, random samples may be drawn for testing of I.1 and, as the case may be, I.2 (cf. the following section on test methods).

For levels 1 and 2 the test must be performed before the waste is brought to the landfill. For level 3 the test is carried out at the landfill.

Test methods

For the assessment of inert waste the following tests I.1 - I.7 may be used:

Ignition loss determination

The content of organic matter is determined as ignition loss at 550⁰C for two hours.

Determination of environmentally harmful substances

The content of environmentally harmful organic substances may be determined by gas chromatographic screening analyses, see Note at the end of the annex.

The content of environmentally harmful inorganic substances may be determined as a total analysis.

Accessibility test

The quantitative content of pollutants in the waste and its identity may be determined by an "accessibility test" which should reflect the upper limit of leaching of substance through simulation of natural leaching behaviour. This may be done, e.g., by a pH-static leaching of crushed material at pH = 7 and 4, at a high liquid/solids ratio (L/S ratio), for example 2 x L/S = 100-200 litres per kg. The identity and concentration of the pollutants (expressed in mg per kg) are determined by analysis of specific parameters on the leached eluate. (The development of the method is not yet complete).

Total chemical composition, (95%)

The total chemical composition (95% knowledge) may be determined by a

chemical analysis based on the total analyses made under I.2. The extent of the analysis is determined on the basis of knowledge of the nature and origin of the waste.

The chemical state in the short term and the long term (for example, redox potential, acid/base ratio) must be described.

Leaching behaviour / reference test

The expected leaching behaviour of the waste as a function of time should be determined, in the case of granular waste, on the basis of column tests. These must describe the leaching behaviour of relevant pollutants at an L/S ratio of 0.1 litres per kg - a maximum of L/S 10 litres per kg. The results should form the reference frames for the leaching behaviour of a waste product. Batch extractions may be added as needed.

NORDTEST has drawn up a description of leaching tests (NORDTEST report No. 272).

Alternatively, for waste in the monolithic form, a tank leaching test may be performed. This is a test method which determines the rate at which a given substance passes from the solid phase to the liquid phase.

Simplified test

With I.5 as reference, a simplified and less time-consuming test must be performed. For granular waste this test should be the (expected) standardised CEN test, which consists of two serial batch extractions, first at L/S = 0-2 litres per kg (6 hours’ contact time) and then at L/S = 2-10 litres per kg (18 hours’ contact time) with an extraction medium of artificial rainwater. The result of this test will be two points on a leaching graph, and the results can then be related directly to the reference leaching behaviour found in I.5.

There is not yet any simplified standard method for waste in the monolithic form.

Ecotoxicological test

For the determination of the ecotoxicological effect of the leachate from a waste product, a duckweed test (or a freshwater gammarus test) may be carried out on the eluate found in I.5 - with the highest concentrations of pollutants.

Depending on the advance knowledge of the type of waste to be landfilled in a landfill unit for mineral waste, the following levels should be used:

Acceptance on the positive list

For waste desired to be accepted on the positive list for Category II, a characterisation test of the waste must be carried out. The characterisation test must include all the surveys II.1 - II.7 (cf. the following section on testing methods) and be assessed in relation to the requirements applying to Category II waste.

Periodical documentation

To substantiate that a type of waste corresponds to a type of waste on the positive list for Category II, an acceptance test must be carried out regularly. Acceptance tests include II.1, II.2 and II.6 (cf. the following section on test methods). For waste received regularly from the same source, the interval between tests could be fixed as 12 months.

Routine investigation

For all loads of waste received at a landfill an identification test must be performed. This test may consist of a visual inspection of the waste. In special cases, random samples may be drawn for testing of II.1 and, as the case may be, II.2 (cf. the following section on test methods).

For levels 1 and 2 the test must be performed before the waste is brought to the landfill. For level 3 the test is carried out at the landfill.

Test methods

For the assessment of mineral waste the following tests II.1 - II.7 may be used:

Ignition loss determination

The content of organic matter is determined as ignition loss at 550⁰C for two hours.

Determination of environmentally harmful substances

The content of environmentally harmful organic substances may be determined by gas chromatographic screening analyses.

The content of environmentally harmful inorganic substances may be determined as a total analysis.

Accessibility test

The quantitative content of pollutants in the waste and its identity may be determined by an "accessibility test" which should reflect the upper limit of the leaching of substance through simulation of natural leaching behaviour. This may be done, e.g., by a pH-static leaching of crushed material at pH = 7 and 4, at a high liquid/solids ratio (L/S ratio), for example 2 x L/S = 100-200 litres per kg. The identity and concentration of the pollutants (expressed in mg per kg) are determined by analysis of specific parameters on the leached eluate. (The development of the method is not yet complete).

Total chemical composition, (95%)

The total chemical composition (95% knowledge) may be determined by a   chemical analysis based on the total analyses made under II.2. The extent of the analysis is determined on the basis of knowledge of the nature and origin of the waste.

The chemical state in the short term and the long term (for example, redox potential, acid/base ratio) must be described.

Leaching behaviour / reference test

The expected leaching behaviour of the waste as a function of time should be determined, in the case of granular waste, on the basis of column tests. These must describe the leaching behaviour of relevant pollutants at an L/S ratio of 0.1 litres per kg - a maximum of L/S 10 litres per kg. The results should form the reference frames for the leaching behaviour of a waste product. Batch extractions may be added as needed.

NORDTEST has drawn up a description of leaching tests (NORDTEST report No. 272).

Alternatively, for waste in the monolithic form, a tank leaching test may be performed. This is a test method which determines the rate at which a given substance passes from the solid phase to the liquid phase.

Simplified test

With II.5 as reference, a simplified and less time-consuming test must be performed. For granular waste this test should be the (expected) standardised CEN test, which consists of two serial batch extractions, first at L/S = 0-2 litres per kg (6 hours’ contact time) and then at L/S = 2-10 litres per kg (18 hours’ contact time) with an extraction medium of artificial rainwater. The result of this test will be two points on a leaching graph, and the results can then be related directly to the reference leaching behaviour found in II.5.

There is not yet any simplified standard method for waste in the monolithic form.

Ecotoxicological test

To determine the ecotoxicological effect of the leachate from a waste product on the leachate treatment plant, a sludge inhibitor test and a nitrification inhibitor test should be carried out on the eluate found in II.5 - with the highest concentrations of pollutants.

Depending on the advance knowledge of a type of waste to be landfilled in a landfill for mixed wastes, the following levels should be used:

Acceptance on the positive list

For waste desired to be accepted on the positive list for Category III, a characterisation test of the waste must be carried out. The characterisation test must include all the surveys III.1 - III.6 (cf. the following section on test methods) and be assessed in relation to the requirements applying to Category III waste.

Periodical documentation

To substantiate that a type of waste corresponds to a type of waste on the positive list for Category III, an acceptance test must be carried out regularly. Acceptance tests include III.1 and III.5 (cf. the following section on test methods). For waste received regularly from the same source, the interval between tests could be fixed as 12 months.

Routine investigation

For all loads of waste received at a landfill an identification test must be performed. In most cases this test will consist only of a visual inspection of the waste.

For levels 1 and 2 the test must be performed before the waste is brought to the landfill. For level 3 the test is carried out at the landfill.

Test methods

For the assessment of the acceptance criteria for mixed wastes the following test methods III.1 - III.6 may be used:

Organic matter determination

The content of organic matter must be determined, basically, as ignition loss at 550⁰C for two hours.

Where it is not possible to draw a representative sample for the determination of ignition loss, the waste should be shredded so that an assessment in terms of volume may be made of the proportion of organic waste as a ratio of the total volume of waste.

Organic matter in the waste should be described, and the biological half-life of the waste should be estimated.

Accessibility test

The qualitative and quantitative content of pollutants in the waste may be determined by an "accessibility test" which should reflect the upper limit of the leaching of substance through simulation of natural leaching behaviour. This may be done, e.g., by a pH-static leaching of crushed material at pH = 7 and 4, at a high liquid/solids ratio (L/S ratio), for example 2 x L/S = 100-200 litres per kg. The identity and concentration of the pollutants (expressed in mg per kg) are determined by analysis of specific parameters on the leached eluate. (The development of the method is not yet complete).

Heterogeneous types of waste from which it is not possible to draw a representative sample on which an accessibility test can be made must be divided into fractions. Thereupon, each fraction must be described with regard to origin, nature, properties and, if possible, chemical composition.

Environmentally harmful substances in each fraction must be identified and, if possible, quantified.

If necessary, an accessibility test must be made on each of the fractions in the waste, whereupon an estimate is made in relation to the proportion that the fractions represent of the total waste matrix for the type of waste.

Main composition of the fractions

The waste must be divided into fractions the chemical composition of which should be described (95% knowledge). The extent of the description should be determined on the basis of the nature and origin of the waste.

The chemical state of each fraction in the short term and the long term (for example, redox potential, acid/base ratio) should be described.

An assessment should then be made of the waste in relation to the proportion that the fractions represent of the total waste matrix for the type of waste.

Leaching behaviour / reference test

The expected leaching behaviour of the waste as a function of time should

be determined, in the case of granular waste, on the basis of column tests describing the leaching behaviour of relevant pollutants at an L/S ratio of 0.1 litres per kg - a maximum of L/S 10 litres per kg. The results should form the reference frames for the leaching behaviour of a waste product. Batch extractions may be added as needed.

NORDTEST has drawn up a description (NORDTEST report No. 272).

Alternatively, for waste in the monolithic form, a tank leaching test may be performed. This is a test method which determines the rate at which a given substance passes from the solid phase to the liquid phase.

Simplified test

With III.4 as reference, a simplified and less time-consuming test must be performed. For granular waste this test should be the (expected) standardised CEN test, which consists of two serial batch extractions, first at L/S = 0-2 litres per kg (6 hours’ contact time) and then at L/S = 2-10 litres per kg (18 hours’ contact time) with an extraction medium of artificial rainwater. The result of this test will be two points on a leaching graph, and the results can then be related directly to the reference leaching behaviour found in III.4.

There is as yet no simplified standard method for waste in the monolithic form.

Ecotoxicological test

To determine the ecotoxicological effect of the leachate from a waste product on the leachate treatment plant, a sludge inhibitor test and a nitrification inhibitor test should be carried out on the eluate found in III.4 - with the highest concentrations of pollutants.

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³ Total analysis means a chemical analysis to determine the sample’s total content of all significant components (the content of oxygen can be calculated if it is known that the material is available in oxydised form, such as Al₂O₃, NaO, etc.). It should be stressed that chemical analyses based on partial digestion of the waste matrix cannot be used, i.e., for types of waste that contain silicates, AAS or ICP/ICP-MS may be used - for example - on samples that were digested with nitric acid according to DS 259. Such samples must be analysed after total digestion with, e.g., hydrofluoric acid and aqua regia, or they must be analysed by means of non-destructive methods such as X-ray fluorescence or neutron activation. If the silicate matrix is not completely digested, misleading results may be obtained for, i.a., a number of trace elements that may be contained in it. Such figures are useless for mass balances, etc.