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Waste Incineration (Scotland) Regulations 2003: Practical Guidance: Edition 2



2.1 Waste Incineration Installations

All waste incineration installations are subject to the Regulations. Regulation 6(a) inserts a definition of "waste incineration installation" into the PPC Regulations. In effect, the definition means that all plants incinerating or co-incinerating waste are captured by the regulations unless the plant does not fall within the definitions of "incineration plant" or "co-incineration plant".

The Regulations also define certain "excluded plant" which incinerate only specific categories of waste. If an incinerator or co-incinerator falls within this definition, it does not need to comply with the technical requirements of the Waste Incineration Directive. However, in these cases, Best Available Techniques ( BAT) will apply.

The Regulations define incineration plant and co-incineration plant as follows:

Incineration plant

"Incineration plant means any stationary or mobile technical unit and equipment dedicated to the thermal treatment of wastes with or without recovery of the combustion heat generated. This includes the incineration by oxidation of waste as well as other thermal treatment processes such as pyrolysis, gasification or plasma processes insofar as the substances resulting from the treatment are subsequently incinerated."

The Regulations also record the range of related operations/equipment around the plant that will also be covered by the above definition, viz:

"This definition covers the site and the entire incineration plant including all incineration lines, waste reception, storage, on site pre-treatment facilities, waste-fuel and air-supply systems, boiler, facilities for the treatment of exhaust gases, on-site facilities for treatment or storage of residues and waste water, stack, devices and systems for controlling incineration operations, recording and monitoring incineration conditions"

Co-incineration plant

"Co-incineration plant means any stationary or mobile plant whose main purpose is the generation of energy or production of material products and:

  • which uses wastes as a regular or additional fuel; or
  • in which waste is thermally treated for the purpose of disposal."

However, if co-incineration takes place in such a way that the main purpose of the plant is not the generation of energy or production of material products but rather the thermal treatment of waste, the plant shall be regarded as an incineration plant."

As with incineration plant, the definition of a co-incinerator extends to related operations and equipment around the plant.

Interpretational examples of which plants fall within the scope of the Regulations are given in Section 2.8 of this guidance.

2.2 Thermal treatment of waste

One of the key terms used in the definitions is "thermal treatment of waste". The following explanations will assist in deciding if a thermal treatment plant is subject to the Regulations.

WID Thermal Treatment: The thermal treatment results in a change to the chemical structure of the original waste, and the change is not reversible. For example, incineration is a thermal treatment in which the carbon and hydrogen present in the original waste gets changed to carbon dioxide and water respectively. Similarly, in pyrolysis and gasification, molecular structure of the original waste is transformed resulting in substances that are physically and chemically different from the original waste.

Non- WID Thermal Treatment: The treatment incorporates the application of heat but without a change in the chemical structure of the waste. Moreover, any physical change is reversible. e.g. drying of sewage sludge removes water - put the water back and you get your original mixture. Similarly, take the case of distillation of waste to separate different fractions. Again, heat is applied and different fractions are collected but there is no change in the chemical structure. Another example will be heating where phase change occurs e.g. there will be a need to heat the tallow in current storage before it can be shipped. However, there is no chemical change and tallow will go solid again when cooled.

Therefore, if a gasification or pyrolysis plant that is treating waste produces a number of waste substances, one or more of which are subsequently burnt on that site, then the Regulations apply to the whole plant. In cases where the waste is gasified (using non-waste gas) and the resultant gas is injected into fuel gas transmission system and that gas is burnt away from the site then those subsequent sites will not be classed as falling under the Directive.

Pyrolysis and gasification plants that are treating waste and which dispose of all their products and residues without thermal treatment (for example by landfill or use as raw materials in other processes) would not be covered by the Regulations. These operations are themselves tightly regulated by the PPC Regulations, the Landfill Regulations or Part II of the EPA.

Thermal treatment plants are those whose main purpose is the disposal of waste. They do not include manufacturing processes. To fall within the scope of the Regulations, a gasification or pyrolysis plant:

  • must involve thermal treatment of waste, and
  • must lead to combustion of gas, residues, char or other substance resulting from the thermal treatment at the incineration plant.

2.3 Technical Unit

Another important aspect of the WID definition of an incineration plant is that the thermal treatment must take place in a 'technical unit'. The definition of installation in the PPC Regulations also refers to a technical unit. There is no definition of technical unit in the Regulations or related EC Directives, but the following provides a guide to the interpretation that will be used by SEPA in determining whether a plant will be subject to the Regulations:

Any piece of equipment that has been specifically designed or adapted for combustion of materials will be regarded as falling within the meaning of technical unit.

This definition will cover virtually all combustion plants, including air curtain destructors. However, it ensures that incineration in non-technical units, bonfires, open burning etc are not subject to the Regulations. These activities may, nonetheless, be subject to enforcement action under separate legislation if they cause nuisance or safety hazards. Disposal of waste in this way may also be contrary to duty of care provisions under Part II of EPA.

2.4 Purpose of the plant

The Executive is aware of plants other than incineration or co-incineration which may involve the burning of a small quantity of waste material as part of a process which is not a waste incineration process. These plants may be excluded from WID by virtue of their purpose rather than the definition of a "technical unit".

It is not possible to provide a complete list of these plants and it may be necessary for SEPA to consider each process on an individual basis. However, some examples are:

  • The cleaning of paint from jigs. Although the paint will be burnt off, the purpose of the process is to clean the jig for reuse;
  • Spent granular activated carbon (for example, as used in some water treatment processes) may be regenerated by heating to remove the adsorbed contaminants. Here, burning of the vapours evolved is for abatement and the process leaves the bulk of the carbon regenerated and ready for further use;
  • The drying of swarf to make the metal waste suitable for feeding into the furnace. Small amounts of oily contaminants present will be burnt but the purpose of the plant is not the incineration of waste;
  • The injection of RFO into a steel furnace to provide carbon for the reduction of iron ore;
  • The use of an afterburner for the abatement of gaseous emissions from plant which is not an incineration plant.

2.5 Which Wastes are covered by the Regulations?

The regulations define waste as any solid or liquid waste as defined in Article 1(a) of the Waste Framework Directive (Directive 75/442/ EEC). This provides that waste shall mean any solid or liquid substance or object in the categories set out in Annex I to the Directive which the holder discards or intends, or is required, to discard.

Burning of gaseous waste is not covered by the Regulations. In this context, gaseous waste includes entrained droplets. Coating processes using solvents with thermal oxidiser to burn waste gas containing VOCs will not be subject to the Regulations. In deciding if the Regulations cover the combustion activity it is also important to consider the state of the original waste. If this original waste is a solid or liquid then the Regulations will apply. For example, pyrolysers treating waste with gas combustor will be covered by the Regulations. The state of the waste considered should be that of the material at ambient temperature and pressure.

Wastes falling within the scope of the regulations include, inter alia, municipal waste, clinical waste, hazardous waste, industrial and commercial waste and waste-derived fuels. Certain plants that burn only specified waste are excluded from the scope of the Regulations (see Section 2.8).

2.6 Definition of Waste

The decision whether a material is waste in a particular situation has to be based on the facts of individual cases. The definition of waste in the Waste Framework Directive has been tested in a number of landmark cases in the European Court of Justice, which have helped to clarify the definition. The key cases are:

(a) Joined Cases C-206/88 and C-207/88 ( Vessoso and Zanetti [1990] 2 LMELR 133) and C-359/88 ( Zanetti and Others) (28 March 1990);

(b) Case C-442/92 Commission of the European Communities v Federal Republic of Germany (10 May 1995);

(c) Joined Cases C-304/94, C-330/94, C-342/94 and C-224/95 (Criminal proceedings against Euro Tombesi and Others) (25 June 1997);

(d) Case C-129/96 ( Inter-Environnement Wallonie v Région Wallonne) (18 December 1997);

(e) Joined Cases C-418/97 and C-419/97 ( ARCO Chemie Nederland Ltd etc) (15 June 2000);

(f) Case C-9/00 ( Palin Granit Oy and Vehmassalon kansanterveystyön kuntayhtymän hallitus) (18 April 2002); and

(g) R v the Environment Agency ex parte Castle Cement Limited (22 March 2001).

Based on the definition of waste in the Waste Framework Directive and interpretation of the above ECJ judgements, the following materials are likely to be considered 'wastes' for the purposes of the regulations. The list provides examples of waste types only: operators should note that the list is not intended to be comprehensive and that the final judgement on what can be considered waste in a particular case lies with the courts.

  • Municipal waste;
  • Clinical waste;
  • Hazardous waste;
  • Sewage sludge;
  • Animal by-products e.g. meat bone meal ( MBM), tallow, specified risk material ( SRM);
  • Waste oils, including recovered fuel oils;
  • Waste vegetable oils;
  • Used drums requiring to be burnt out;
  • Contaminated wood;
  • Waste derived fuels;
  • Production residues;
  • Out of spec and out of date products;
  • Chicken litter;
  • Decommissioned explosives;
  • Sludge from recycled paper pulp production.

Any cleaning or processing of the material prior to its disposal at an incinerator or a co-incinerator is unlikely to alter its status, i.e. in most cases it will remain a waste. This means that process industries that produce residues including contaminated batches of products, which can be used as fuel substitutes in on-site boilers, will fall within the scope of the Regulations.

2.7 Hazardous and Non-Hazardous Waste

The Regulations cover both hazardous and non-hazardous waste. However, some of the technical requirements of the Regulations are different depending on whether the waste is hazardous or non-hazardous.

Hazardous waste

For the purposes of the Regulations, 'hazardous waste' means any solid or liquid waste as defined in Article 1(4) of Council Directive 91/689/ EEC on hazardous waste. Since 1 January 2001 this, in practice, means a solid or liquid waste included in the European Waste Catalogue (Commission Decision 2000/532/ EC, published in OJ L 226, 6.9.2000, p3) and marked there with an asterisk (*).

However, the requirements of the Regulations that apply to hazardous waste are disapplied to the categories of hazardous waste set out below. These requirements include those relating to the reception, sampling, analysis and combustion temperatures applying to hazardous waste.

(a) combustible liquid wastes, including waste oils as defined in Article 1 of Council Directive 75/439/ EEC of 16 June 1975 on the disposal of waste oils, provided that they meet the following criteria:

(i) the mass content of polychlorinated aromatic hydrocarbons, e.g. polychlorinated biphenyls ( PCB) or pentachlorinated phenol ( PCP) amounts to concentrations not higher than those set out in the relevant Community legislation;

(ii) these wastes are not rendered hazardous by virtue of containing other constituents listed in Annex II to Directive 91/689/ EEC in quantities or in concentrations which are inconsistent with the achievement of the objectives set out in Article 4 of Directive 75/442/ EEC; and

(iii) the net calorific value amounts to at least 30 MJ per kilogramme.

(b) any combustible liquid wastes which cannot cause, in the flue gas directly resulting from their combustion, emissions other than those from gasoil as defined in Article 1(1) of Directive 93/12/ EEC or a higher concentration of emissions than those resulting from the combustion of gasoil as so defined.

Non-hazardous waste

These constitute wastes other than those that fall under the definition of hazardous waste.

2.8 Exclusions

The Regulations provide that plants incinerating or co-incinerating certain types of waste ("excluded plants") are not waste incineration installations within the meaning of the Regulations. This means that they do not need to comply with the technical requirements of the Waste Incineration Directive. Excluded plants with a capacity of 1 tonne or more per hour will be regulated as Part A installations under PPC. Excluded Plants with a capacity of 50kg or more per hour but less than 1 tonne per hour will be regulated as Part B installations under PPC and those with a capacity of less than 50kg per hour will be regulated under the Waste Management Licensing regime.

The capacity of an installation will be determined by SEPA on a case by case basis. The starting point will be the operator's description of the installation, the manufacturer's nameplate capacity, and the operating regime used by the operator.

Operators should take a view in the first instance whether their plant is excluded or not. The final decision, however, on whether a particular installation meets the criteria stipulated in the Regulations and, therefore, whether the plant is an excluded plant, is for SEPA to take.

Excluded plants fall into two principal categories. The first covers plants treating only specified wastes; the second covers experimental plants.

It should be noted that even when an incinerator is deemed to be an excluded plant the activity may still require a PPC permit to operate, and the plant will be subject to BAT consideration. The benchmark for the BAT consideration will be indicated by the requirements and standards within the PPC Regulations. As new techniques become available, or are refined, BAT may require a plant to operate to standards tighter than those in the Regulations. It should also be noted that the requirements of the Regulations only cover part of the BAT assessment. The operator will need to demonstrate BAT across the full range of areas covered by it, as detailed in the PPC Regulations.

Plants treating only specified wastes

The technical requirements of the Waste Incineration Directive do not apply to plants provided they treat only the wastes specified below. It should be noted that a plant may burn one (or more) of these wastes, alone or in combination with conventional non-waste fuels, and still be regarded as an excluded plant. However, if a plant uses any other wastes in combination with any of the specified wastes, the exclusion does not apply and the plant will be regulated as a waste incineration installation.

Vegetable waste from agriculture and forestry

Plants treating vegetable waste from either agricultural or forestry industry are excluded plants. No definition of the word vegetable is given in the Directive. This exclusion was not intended to cover substances manufactured from vegetable matter, and so for the purposes of this part of the Regulations 'vegetable' should be interpreted as covering naturally occurring, non-manufactured substances. This includes vegetable waste from horticulture, but will not include the container in which the plant was grown.

For example, a plant burning raw vegetable waste from a farmers' market would be covered by the exclusion, but a plant burning rape seed oil would not be covered as this is from a commercial operation, not an agricultural activity.

Vegetable waste from the food processing industry

Plants treating vegetable matter from the food processing industry are excluded plants providing the heat generated is recovered. The treatment and heat generation activity that can benefit from this exclusion is not restricted to the site of the food processing industry producing the waste. This exclusion does not apply to waste which contains material of animal origin.

Fibrous vegetable waste from pulp-making

Plants treating fibrous vegetable wastes from virgin pulp production and from production of paper from pulp are excluded plants provided this happens on the site of the waste generation and the heat generated is recovered. Wastes from pulp production plant are excluded only if the pulp production is from virgin materials. However, plants treating fibrous vegetable waste from paper production are excluded whether the pulp used is from virgin or recycled sources.

Wood waste

Plants treating only wood waste, with the exception of wood waste which may contain halogenated organic compounds or heavy metals as a result of treatment with wood-preservatives or coating, are excluded plants.

For example, a plant that burns only waste sawdust from a saw mill that only handles virgin wood products and does not apply any wood preservatives or coatings is likely to be able to demonstrate that it can fall within this exclusion. For clarity, fibre board can be classed as wood, for the purposes of this exclusion.

The Executive recognises that some manufacturers producing fibre board do not use chemicals containing halogens or heavy metals in the manufacturing process. In this case, a plant burning only such fibre board would be excluded from WID. However, if the wood waste used for the manufacture of the fibre board was already contaminated, then the final product may be also contaminated (note: the WID does not specify at what point the contamination has to take place), consequently the exclusion might not be applicable. However, this is a question of fact and the onus is on the operator of the incineration or co-incineration plant to demonstrate that the wood waste originally used did not arise from treated wood.

There are three issues to note in relation to wood waste:

  • Wood cannot be taken to include paper and card;
  • Some untreated wood products, such as wood pallets, may become unintentionally or accidentally contaminated during their normal use with organic chemicals and/or heavy metals. However, the WID exclusion would still apply because the contamination is not "as a result of treatment with wood preservatives or coating". Operators wishing to take advantage of this exclusion will have to demonstrate to the regulator that the contamination is accidental and not as a result of a treatment process; and
  • Particular care is needed concerning wood waste originating from construction and demolition waste. The exception does not mean that wood waste originating from construction and demolition waste will always be deemed to contain halogenated organic compounds or heavy metals. However, particular attention shall be paid to such waste as it may well contain halogenated organic compounds and heavy metals. It will be for the operator to demonstrate that such wood waste is not contaminated.

Operators wishing to take advantage of this exclusion will have to demonstrate that their source of supply is such that there is no possibility of treated wood being mixed with untreated wood.

Cork waste

Plants treating only cork waste are excluded plants. Untreated cork products that become contaminated during their normal use are not excluded.

Radioactive waste

The Regulations do not apply to plants that burn only radioactive waste.

Animal carcasses

Incinerators that burn only animal carcasses as regulated by Regulation ( EC) No 1774/2002 ("the Animal By-Products Regulation")* are excluded from the scope of the WID. For this purpose, the Executive considers as being excluded from the WID, incinerators which burn only animal carcasses, including those carcasses which have been cut, for example, to ease transportation or to facilitate incineration at the point of disposal.

In this context, "animal carcasses" mean carcasses or parts of carcasses (as described above). This means that incineration plants that burn only this material will be considered to be excluded from the WID. This will include low capacity incinerators in relation to pet crematoria.

Unprocessed animal by-products are potentially excluded from the WID to the extent that arrangements for dealing with them are regulated by the ABPR. This approach does not extend to any unprocessed animal by-products which are not regulated under the ABPR (because they are unable to meet the criteria set out therein).

However, this approach does not extend to any processed animal by-products such as tallow or MBM or to products of animal origin such as former foodstuffs or catering waste.

* Article 12 as read with Annex IV, both of Regulation ( EC) No 1774/2002 in particular make provision for the incineration of animal by-products. This Regulation is enforced in Scotland by the Animal By-Products (Scotland) Regulations 2003 ( SSI 2003 No 411).

Experimental plant

Experimental plants used for research, development and testing are also excluded plants. However, for this exclusion to apply two further conditions must be met:

  • The research, development or testing must be in order to improve the incineration process; and
  • The plant must treat less than 50 tonnes of waste per year.

This exclusion would not apply to substitute fuel trials (e.g. at cement kilns), as these types of plants are not experimental plant but are production plant being used to trial a fuel mix. In addition, the trialing of such fuels is likely to exceed the 50 tonnes limit of this exclusion.

Section 5.1 of Schedule to the Pollution Prevention and Control Regulations.

Operators should be aware that although plant may be excluded from the WID this does not mean that they are also excluded from Section 5.1 (Incineration and Co-incineration of Waste) of Schedule 1 to the Pollution Prevention and Control (Scotland) Regulations 2000 (the PPC Regulations).

2.9 Interpretational Examples

From the above, it can be seen that there are a number of factors which influence whether a plant is considered a waste incineration installation or an excluded plant. A number of examples are provided below to set these criteria in a practical context.

Roadstone coating

Roadstone coating plant where waste oil, or recovered oil, is burned as a fuel in the rotary dryers would fall under the definition of a co-incineration plant and would, therefore, be regulated as a WID plant under Part A , sub-paragraph (e) of the amended Section 5.1 of Schedule 1 to the PPC Regulations.

Small waste oil burners

Small waste oil burners ( SWOBs) are those appliances with a net rated thermal input of less than 3 megawatts, and were regulated as a Part B process under the EPA or PPC regime. These appliances are commonly used to dispose of waste oils from vehicle servicing on garage premises.

SWOBs are considered to fall within the scope of WID because:

  • They constitute a 'technical unit' (see Section 2.3);
  • The process involves thermal treatment of a waste (see Section 2.2); and
  • Although the scale of the activity is normally small, there is no de-minimus threshold within the Regulations (this is a direct read-across from the Waste Incineration Directive).

The interpretation of technical unit is, in this context, one that has been specifically designed or adapted for combustion of materials.

Production residues and off-cuts

Certain factories and manufacturing processes will produce residues and/or off-cuts during the production process. In many cases these materials will be waste materials.

If the waste materials were utilised in a boiler that generates steam or energy, for use on or off the site, then the boiler would fall within the definition of a co-incineration plant. The Regulations would then apply unless the plant fell within the definition of excluded plant as a result of the waste it burns (see Section 2.8).

Wood wastes

Combustion plants treating only certain wood wastes are excluded plants (see Section 2.8). However, the combustion of wood waste that may contain halogenated organic compounds or heavy metals as a result of treatment with wood preservatives or coating is not excluded. For clarity, unless an operator can guarantee that the source of the waste wood being combusted could not include wood containing such halogenated organic compounds or heavy metals, then the plant will be treated as a waste incineration installation.

Furthermore, any plant combusting off-cuts from a manufacturing process after wood preservative or coating containing halogenated organic compounds or heavy metals has been applied must be regarded as falling outwith the exclusion.