BIOLOGICAL TREATMENT OF BIODEGRADABLE WASTE

Transcription

1 EUROPEAN COMMISSION DIRECTORATE-GENERAL ENVIRONMENT Directorate E - Industry and environment ENV.E.3 - Waste management Brussels, 20 October 2000 DG ENV.E.3/LM/biowaste/1 st draft WORKING DOCUMENT BIOLOGICAL TREATMENT OF BIODEGRADABLE WASTE 1 st draft This working document is intended as a basis for preliminary discussions. It represents the opinion of DG ENV.E.3 only and does not necessarily engage the Commission The document can also be found on the Commission web site Europa:

2 WORKING DOCUMENT BIOLOGICAL TREATMENT OF BIODEGRADABLE WASTE An EU-initiative to improve the present situation for biodegradable waste management and help meeting the targets of the Landfill Directive 1999/31/EC could be based on Articles 95 and 175 EC Treaty and should include the following elements: Objectives To promote the biological treatment of biodegradable waste by harmonising the national measures concerning its management in order to prevent or reduce any impact thereof on the environment, thus providing a high level of environmental protection. To ensure the functioning of the internal market and to avoid obstacles to trade and distortion and restriction of competition within the Community. To protect the soil and ensure that the use of biologically treated biowaste enhances soil quality. Scope The collection and treatment of biodegradable wastes as listed in Annex I as well as the production, trade and shipment of compost and stabilised biodegradable waste. Definitions The following definitions are proposed: (1) waste means any substance or object which is covered by Directive 75/442/EEC; (2) biodegradable waste means any waste that is capable of undergoing anaerobic or aerobic decomposition; (3) green waste means vegetable waste from gardens and parks, tree cuttings, branches, grass, leaves (with the exception of street sweepings), saw dust, wood chips and other wood waste not treated with heavy metals or organic compounds; (4) compost means the odourless, stable and humus-like material rich in organic matter as well as proteins and carbohydrates issued from the composting process of biodegradable waste; (5) digestate means the solid, fibrous fraction resulting from the anaerobic digestion of biodegradable waste that has to be further composted before being spread on land; (6) liquor means the liquid fraction from the anaerobic digestion of biodegradable waste that has to be suitably treated to comply with the requirements of Directive 91/271/EEC before being released into surface water; (7) biogas means the mixture of carbon dioxide, methane and trace gases resulting from the anaerobic digestion of biodegradable waste, with the exclusion of landfill gas; 2

3 (8) stabilised biodegradable waste means the waste resulting from the mechanical/ biological treatment of unsorted waste or residual municipal waste; (9) composting means the aerobic decomposition of biodegradable waste under controlled conditions and their reconstitution into humus by the action of micro- and macro-organisms, involving the bonding of as much as possible nitrogen onto carbon molecules, fixing proteins and carbohydrates in forms readily available to plants in order to produce compost; (10) in-vessel composting means the composting of biodegradable waste in a closed reactor with minimised thermal exchange with the atmosphere and where the composting process is accelerated by an optimised air exchange, water content and temperature control; (11) home composting means the composting of the biodegradable waste as well as the use of the compost in a garden belonging to a private household; (12) on-site composting means the composting of the biodegradable waste as well as the use of the compost on the site itself where the waste is generated; (13) community composting means the composting of biodegradable waste by a group of people in a locality with the aim at composting their own and other people s biodegradable waste in order to manage the supplied biodegradable waste as close as possible to the point at which it was produced; (14) anaerobic digestion means the anaerobic decomposition and biodegradation of biodegradable waste under controlled conditions by the action of micro-organisms (methanogenic bacteria) in order to produce methane in the form of biogas and, as residue, a fibre fraction (digestate) and a liquid fraction (liquor); (15) mechanical/biological treatment means the stabilisation of residual municipal waste, unsorted waste or any other biodegradable waste unfit for composting or anaerobic digestion in order to reduce the fermentability and volume of the waste; (16) plant means any technical unit and equipment dedicated to the treatment of biodegradable waste via composting, anaerobic digestion or mechanical/biological stabilisation as well as any equipment dedicated to the treatment of air emissions and waste water; (17) separate collection means the collection of biodegradable waste separately from other kind of wastes in such a way as to prevent the different waste fractions or waste components from being mixed, combined or contaminated with other potentially polluting wastes, products or materials; (18) municipal waste means waste from households, as well as commercial, industrial, institutional and other waste which, because of its nature or composition, is similar to waste from households; (19) residual municipal waste means the unsorted fraction of municipal waste left over after source separation and unsuitable for the production of good quality compost because is mixed, combined or contaminated with potentially polluting products or materials; 3

4 (20) producer means the person legally responsible for carrying out composting, anaerobic digestion or mechanical/biological stabilisation of biodegradable waste; (21) hygienisation means the treatment of biodegradable waste aiming at killing vegetative forms of pathogenic micro-organisms during the production of compost and biogas in such a way that the risk of carrying disease in connection with further treatment, trade and use is minimised; (22) impurities means the presence in compost and digestate of fragments of plastic, glass, metals or similar non-biodegradable materials, with the exclusion of sand, gravel and small stones. General principle An improved management of biodegradable waste in the Community should encourage whenever environmentally justified and taking into consideration the costs the following management options, in this order: (1) the prevention or reduction of biodegradable waste production (e.g. sewage sludge) and its contamination by polluting substances and impurities, (2) the reuse of biodegradable waste (e.g. cardboard), (3) the recovery of separately collected biodegradable waste into the original material (e.g. paper and cardboard) whenever environmentally justified, (4) the composting or anaerobic digestion of separately collected biodegradable waste that is not recovered into the original material, (5) the mechanical/biological stabilisation of unsorted biodegradable waste, (6) the use of biodegradable waste as a source for generating energy. Home and on-site composting A specific place would have to be guaranteed to home and on-site composting in view of the environmental advantages that these practices may have. In particular, Member States should encourage home and on-site composting whenever there are viable outlets for the resulting compost such as private gardens, community allotments, public parks and farmland. They should ensure that an appropriate information campaign is carried out in order to inform the general public on how to make compost and to illustrate the benefits for the environment from recycling biodegradable waste prior to any action to promote home or on-site composting. Local authorities should be encouraged to compost on site their own biodegradable waste arising such as green waste from cemeteries and public parks. Community composting Member States should encourage the setting up of community composting facilities as a way of involving the general public in the management of their own waste, reducing transport of waste and increasing awareness in waste recycling practices. Compost produced in a community composting scheme and used on the site of production or on the premises of those taking part in the community composting scheme itself and as long as the yearly compost production does not exceed 100 tonnes (fresh weight) [corresponding to about 2,000 people taking part to the scheme] should be exempted from a number of provisions (permit 4

5 requirement, reduced frequency for analyses, labelling). On the contrary, compost produced in a community composting facility that is given away for free or is sold, traded or marketed to people other than those taking part in the community composting scheme should not be exempted from any provision. Separate collection Member States should set up, where they are not already in place, separate collection schemes with the aim at collecting biodegradable waste separately from other kinds of waste in such a way as not to contaminate biodegradable waste with polluting wastes, materials and substances. In particular, the following biodegradable wastes if it can be reasonably expected that their biological treatment will not significantly worsen the quality of the resulting compost and digestate, and unless entailing unreasonable costs if compared to the environmental benefits achievable should be separately collected, unless they are home composted or community composted: (a) (b) (c) (d) (e) (f) food waste from private households; food waste from restaurants, canteens, schools and public buildings; biodegradable waste from markets; biodegradable waste from shops, small businesses and service undertakings; biodegradable waste from commercial, industrial and institutional sources unless used on site; green wastes from private as well as public parks, gardens and cemeteries. Although paper and cardboard are biodegradable waste that could be and, indeed, are quite easily composted, it is felt that paper and cardboard waste should be as a general rule reused or recycled into new paper or cardboard. This should not apply to specific locations such as islands far away from the mainland where it may be more environmentally sensible to compost waste paper and cardboard together with other biodegradable waste. The separate collection schemes should be organised in such a way that any nuisance caused in particular by odours, insects, rodents, dust and noise is minimised during collection, transport and treatment. These separate collection schemes should at least cover: (a) (b) urban agglomerations of more than inhabitants within a given time frame, e.g. three years; urban agglomerations of more than inhabitants within a longer time frame, e.g. five years. Special conditions could be granted to rural or scarcely populated areas with a density of less than 10 inhabitants per square kilometre in which the setting up of separate collection schemes would not be environmentally justified. In these areas special campaigns to particularly promote home and on-site and community composting should take place. 5

6 In order to avoid an unjustified increase in the quantity of sewage sludge, it should be prohibited to shred solid biodegradable waste with a view to evacuating it via the sewer. Residual municipal waste The amount of residual municipal waste that cannot be separately collected should be progressively reduced, to the extent possible. The residual municipal waste that cannot be separately collected should be treated prior to landfilling as required by the Landfill Directive in order to: (a) (b) (c) remove to the extent possible hazardous waste; separate materials suitable for recycling; reduce the organic matter content and its fermentability via a mechanical/ biological stabilisation process with a view to achieving a moisture level of less than 50% and a Respiration index value of less than 400 mg O 2 /kg VS/h. Before being incinerated, residual municipal waste that cannot be separately collected should be treated in order to separate materials suitable for recycling. Composting The composting process of biodegradable waste should have the purpose of transforming this waste into good quality compost suitable for the improvement of the soil and should be carried out in such a way as to minimise the impact on the environment of air emissions and leaching to surface or groundwater as well as to minimise the health impact for aerosols on the workers at the plant. The requirements that have to be complied with in order to ensure a sufficient level of hygienisation of the final compost are in Annex II. Anaerobic digestion The anaerobic digestion treatment of biodegradable waste should have the purpose of reducing the fermentability of this waste, maximise the production of biogas, and ensuring that the digestate can be used for the production of compost. It should be carried out in such a way as to minimise the impact on the environment of air emissions and leaching to surface or groundwater as well as to minimise the health impact for aerosols on the workers at the plant. The liquor from an anaerobic digestion plant shall be suitably treated to comply with the requirements of Directive 91/271/EEC before being released into surface water. The management of biogas from anaerobic digestion plant shall be carried out according to the requirements in Annex VI. Permit requirements The provisions set out in Article 9 of Directive 75/442/EEC should be specified and supplemented, so as to ensure that no biological treatment plant operates without a permit. The permit should take into account the presence of neighbouring buildings, rivers and lakes and set minimum distances accordingly. The application for a permit to the competent authority should include a description of the measures which are envisaged to guarantee that the requirements of Annex V are complied with, in particular that leachates, run-off waters, storm water, waste water and exhaust air are properly treated before being released into the environment. 6

7 The permit granted by the competent authority to a plant should explicitly list, according to the European Waste Catalogue (EWC), the categories of biodegradable wastes which may be treated, and should set the maximum annual quantity of biodegradable waste whose treatment is allowed in the plant. An exemption from the permit requirement could be given to biological treatment plants with a total annual output of 100 tonnes of compost or digestate (fresh weight). Compost Compost should be produced, imported, traded and marketed in the Community according to one of the environmental quality classes set out in Annex III. Compost of class 1 could be used according to best agronomic practice without any specific restriction. Compost of class 2 could be used in a quantity not exceeding 10 tonnes dry matter per hectare per year. Compost of class 3 could be used in a quantity not exceeding 5 tonnes dry matter per hectare per year. Whenever justified for ensuring a higher level of environmental protection or for improving the quality and characteristics of the soil, the competent national authority should be allowed to decide, on a case-by-case basis, on lower or higher maximum allowable quantities per hectare and per year than those mentioned above. Stabilised biodegradable waste The mechanical/biological treatment of biodegradable waste shall achieve a moisture level of less than 50% and a Respiration index value of less than 400 mg O 2 /kg VS/h. Stabilised biodegradable waste could be used as a substitute of virgin soil in those land applications that are not destined to food and fodder crop production, such as final landfill cover with a view to restoring the landscape, landscape restoration in old and dismissed quarries and mines, anti-noise barriers, trenches in road construction, golf course, sky slopes, football pitches and the likes. These uses should be allowed on condition of not being repeated for at least 10 years and for a total quantity not exceeding 200 tonnes of dry matter per hectare for stabilised biodegradable waste of type A and 100 tonnes of dry matter per hectare of stabilised biodegradable waste of type B. The spreading on land of stabilised biodegradable waste should at least be subject mutatis mutandis - to the provisions of Articles 5 (1) [heavy metal limits in soil], 9 [soil analysis & analytical methods] and 10 [record keeping] of Directive 86/278/EEC. Sampling requirements The producer of compost should be responsible for the quality of the compost produced and shall ensure that compost is as less contaminated as possible from pathogens, weed seeds and other substances or materials that could present problems for soils, crops, animals or man. In particular, the producer should guarantee that compost complies with the relevant limit values set in Annexes II and III and has been analysed according to the frequencies and procedures set in Annex IV. 7

8 Labelling and shipment requirements Compost that is imported, produced or marketed within the Community should carry a label bearing the following information: (a) the words EU Compost Class followed by the appropriate number, i.e. 1 or 2 or 3, according to Annex III; (b) (c) (d) (e) (f) (g) (h) the name or trade name or trademark and the address of the person responsible for marketing, established within the Community; the name and address of the site of production; the feedstock for all components that represent more than 10% weight/weight; detailed information on the parameters listed in Annex IV; the certification of the producer that compost respect the limit values set out in Annex II as regards pathogens; guaranteed net weight; specific information to the end user for a correct application and use of compost with special regard to feedstock composition, type of treatment and grade of maturity, and the maximum quantities that can be used on land according to Article 11. The shipment of stabilised biodegradable waste within, into and out the Community should be subject to the relevant provisions of Council Regulation (ECC) No 259/93. Packaging compatible with biological treatment There should be a possibility for adopting provisions for the testing, labelling and entry into the market of packaging deemed to be compatible with the biological treatment of biodegradable waste. In particular, it is proposed that a harmonised packaging logo be adopted at Community level. This logo would allow the general public an informed choice about packaging materials and would help in the separate collection of biodegradable waste. Public procurement Public authorities should use compost as substitute for peat and other raw materials extracted from the environment (such as phosphate rock and sand) whenever possible, in particular as a component in soil improvers, growing media, mulches, potting soil and in soil dressing for landscaping purposes. Appropriate measures to encourage the use of compost in public procurement contracts should be established. 8

9 ANNEX I Biodegradable wastes [this Annex would have to be brought in line with the updated European Waste Catalogue] List of biodegradable wastes in principle suitable for biological treatment. The 6-digit code refers to the correspondent entry in the European Waste Catalogue adopted with Commission Decision 94/3/EC Wastes from agricultural, horticultural, hunting, fishing and aquaculture primary production, food preparation and processing animal tissue waste [only low risk animal waste in the sense of Directive 90/667/EEC] plant tissue waste animal faeces, urine and manure (including spoiled straw), effluent, collected separately and treated off-site Wastes from the preparation and processing of meat, fish and other foods of animal origin sludges from washing and cleaning sludges from on-site effluent treatment Wastes from fruit, vegetables, cereals, edible oils, cocoa, coffee, tea and tobacco preparation, processing; conserve production; tobacco processing materials unsuitable for consumption or processing sludges from washing, cleaning, peeling, centrifuging and separation sludges from on-site effluent treatment Wastes from sugar processing sludges from on-site effluent treatment Waste from the dairy products industry materials unsuitable for consumption or processing sludges from on-site effluent treatment from the dairy products industry Wastes from the production of alcoholic and non-alcoholic beverages wastes from washing, cleaning and mechanical reduction of the raw material wastes from spirits distillation sludges from on-site effluent treatment from the baking and confectionery industry sludges from on-site effluent treatment from the production of alcoholic and nonalcoholic beverages Wastes from wood processing and the production of paper, cardboard, pulp, panels and furniture waste bark and cork sawdust shavings, cuttings, spoiled timber/particle board/veneer bark dregs and green liquor sludge (from black liquor treatment) from pulp, paper and cardboard production and processing

10 fibre and paper sludge from pulp, paper and cardboard production and processing Wastes from the leather and textile industries sludges free of chromium from the leather industry wastes from unprocessed textile fibres and other natural fibrous substances mainly of vegetable origin wastes from unprocessed textile fibres mainly of animal origin Packaging; absorbents, wiping cloths, filter materials and protective clothing not otherwise specified paper and cardboard packaging wooden packaging Wastes from waste treatment facilities, off-site waste water treatment plants and the water industry sludges from the treatment of urban waste water anaerobic treatment sludges of animal and vegetal wastes from anaerobic treatment of wastes Municipal waste and similar commercial, industrial and institutional wastes including separately collected fractions separately collected paper and cardboard from MSW separately collected wood from MSW organic compostable kitchen waste (including frying oil and kitchen waste from canteens and restaurants) compostable waste from gardens, parks and cemeteries waste from markets It shall be prohibited to compost sludge if the sludge does not comply with the limits for sludge use in agriculture as set by the Sewage Sludge Directive 86/278/EEC. 10

11 ANNEX II Hygienisation requirements [this Annex would have to be brought in line with the updated Sewage Sludge Directive] 1. PROCESS VALIDATION TEST An indicator organism shall be used in order to determine the effectiveness of the treatment in hygienising biodegradable waste. This test shall be carried out for each treatment plant within 12 month of its starting up phase. The test shall be repeated if the composition of the biodegradable waste significantly changes or if major modifications to the process treatment are made. The indicator organisms shall be Salmonella senftenberg W775 (H 2 S negative). 2. PROCESS MANAGEMENT 2.1. Composting The composting process shall aim at the aerobic decomposition of biodegradable waste under controlled conditions and its reconstitution into humus by the action of micro- and macroorganisms, involving the bonding of as much as possible nitrogen onto carbon molecules, fixing proteins and carbohydrates in forms readily available to plants in order to produce compost. The composting process shall be carried out in such a way that a thermophilic temperature range, a high level of biological activity under favourable conditions with regard to humidity and nutrients as well as an optimum structure and optimum air conduction are guaranteed over a period of several weeks. Water content should be at least 40% and the ph approximately 7. In the course of the composting process the entire quantity of the biodegradable waste shall be mixed and exposed to a temperature of: 55 C as a minimum for at least two weeks; or 65 C as a minimum for at least one week (60 C in case of in-vessel composting) Anaerobic digestion The anaerobic digestion process shall aim at the anaerobic decomposition of biodegradable waste under controlled conditions, its reconstitution into humus by the action of microorganisms (methanogenic bacteria) as well as the production of biogas. The anaerobic digestion process shall be carried out in such a way that a minimum temperature of 55 C is maintained over a period of 24 hours without interruption and that the hydraulic dwell time in the reactor is at least 20 days. In case of lower operating temperature or shorter period of exposure 11

12 the biodegradable waste shall be pre-treated at 70 C for 1 hour, or the digestate shall be post-treated at 70 C for 1 hour, or the digestate shall be composted. 3. MONITORING The relevant parameters of the biological treatment (temperature for composting and temperature as well as hydraulic dwell time for anaerobic digestion) shall be recorded each day. These records shall be kept for five years and made available to the competent authorities upon request. In order to allow a proper monitoring and the process validation procedure, the biological treatment plants shall have appropriate openings to allow for the insertion and extraction of samples and the recording of the relevant parameters of the process. 4. END-PRODUCT REQUIREMENTS Compost is deemed to be sanitised if it complies with the following: Salmonella streptococchi absent in 50 g of compost/digestate Clostridium perfringens absent in 1 g of compost/digestate If compost or digestate is found to contain Salmonella streptococchi or Clostridium perfringens, this is considered to be indication of inadequate hygienisation. The competent authority shall be immediately informed and opportune actions undertaken to redress the situation. If a second check on compost or digestate gives the same result, the competent authority shall suspend the permit of the plant until the situation is properly addressed. Compost shall also be tested for the following: Germination test (Three different plant species from each category of those listed in OECD Test Guideline 208) Plant biomass (% as reference medium) Germination delay (days) Germination ratio (%) Percentage of compost (mass/mass): 15% Percentage of compost (mass/mass): 45% Percentage of compost (mass/mass): 60% [Cfr. ISO (1995): Determination of the effects of pollutants on soil flora Effects of chemicals on the emergence and growth of higher plants.] Compost shall have less than three germinating weed seeds per litre. Community standards for the process validation test, the end-product requirements and for sampling should be developed. Until these standards are approved, Member States may apply national standards and procedures. 12

13 ANNEX III Environmental quality classes for compost and stabilised biodegradable waste types Compost Stabilised biodegradable waste Organic matter (%) Cd (mg/kg dm) Cr (mg/kg dm) Cu (mg/kg dm) Hg (mg/kg dm) Ni (mg/kg dm) Pb (mg/kg dm) Zn (mg/kg dm) PCBs (mg/kg dm) (*) PAHs (mg/kg dm) (*) Impurities >2mm Class 1 Class 2 Class 3 Type A Type B >30 >30 >25 >20 > <0.5% w/w <0.5% w/w <1% w/w <3% w/w <3% w/w (*): Threshold values for these organic pollutants to be set in consistence with the Sewage Sludge Directive. Compost and stabilised biodegradable waste shall belong to a specified class or type if, for each concentration limit considered individually, the 90-percentile of the samples within a twelve-month period are at or below the threshold value and if the 10-percentile of the samples exceed only one threshold value and by less than 20%. 13

14 ANNEX IV Sampling frequency and methods for analysis and sampling [this Annex would have to be brought in line with the updated Sewage Sludge Directive] (1) In order to inform the end user about the characteristics of compost and stabilised biodegradable waste, the following parameters shall be analysed and declared: Parameter Unit Reference method (*) Dry matter % fresh weight EN Soil improvers and growing media determination of organic matter and ash Organic matter % dm EN Soil improvers and growing media determination of organic matter and ash Water content % fresh weight EN Soil improvers and growing media determination of physical properties Bulk density kg/l fresh weight EN Soil improvers and growing media determination of physical properties Electrical conductivity ms/m EN Soil improvers and growing media determination of electrical conductivity Maturity index ph(h 2 O) ph-unit EN Soil improvers and growing media determination of ph Nitrogen (as total N and NH 4 -N) mg /kg dm pren parts 1 and 2 Soil improvers and growing media total N modified Kjeldahl/Dumas Phosphorus (as P 2 O 5 ) mg /kg dm pren Soil improvers and growing media extraction of aqua regia soluble elements Potassium (as K 2 O) mg /kg dm pren Soil improvers and growing media extraction of aqua regia soluble elements Calcium (as CaO), magnesium (as MgO), boron (B), molybdenum (Mo) mg /kg dm pren Soil improvers and growing media extraction of aqua regia soluble elements C/N - Total impurities % dm Salmonella spp number/50 g dm Clostridium perfringens number/1 g dm Germination test - ISO Determination of the effects of pollutants on soil flora Effects of chemicals on the emergence and growth of higher plants. Germinating weed seeds number/l [ÖNORM S 2023] Heavy metals: cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), zinc (Zn) PAHs mg/kg dm [ISO 13877] PCBs mg/kg dm [CD 10382] (*) Latest available edition. mg/kg dm pren Soil improvers and growing media extraction of aqua regia soluble elements (2) The analyses shall be carried out: (a) every six months for plants producing up to tonnes of compost or stabilised biodegradable waste per year; 14

15 (b) (c) at intervals of at least every tonnes of compost or stabilised biodegradable waste produced or every 3 months, whichever comes first, for plants producing more than and up to tonnes of compost or stabilised biodegradable waste per year; every month for plants producing more than tonnes of compost or stabilised biodegradable waste per year. (3) The competent authority may decrease or increase the frequency of analysis as set in the previous paragraph based on monitoring data, changes in the waste stream or processing techniques, effectiveness of the separate collection of the biodegradable waste or the potential presence for toxic substances. (4) The competent authority may decide on a case-by-case basis and whenever justified on the analysis of parameters other than those listed above. (5) The analyses shall be carried out by a laboratory independent from the producer and certified by the competent authority. Sample collection, preservation and analysis must assure valid and representative results. (6) The results of these analyses shall be printed on the label or on the accompanying information sheet. (7) Other methods for compost, digestate and stabilised biodegradable waste examination to be used are the following: Parameter Unit Reference method (*) Sampling - EN Soil improvers and growing media sampling Odour OU/m³ [CEN/TC 264 /WG 2] Odours - Odour concentration measurement by dynamic olfactometry Salmonella senftenberg (*) Latest available edition. (8) Community standards for the parameters listed in this Annex should be developed. Until these standards are approved, Member States may apply national standards and procedures. 15

16 ANNEX V General requirements for biological treatment plants 1. Location The location of a treatment plant must take into consideration requirements relating to: the distance from the boundary of the site to residential and recreation areas, waterways, water bodies and other agricultural and urban sites, the existence of groundwater, coastal water or nature protection zones in the area, the protection of the nature or cultural patrimony area. 2. Waste water and leachate management Appropriate measures shall be taken, with respect to the characteristics of the biodegradable waste treated on the site and meteorological conditions, in order to: collect contaminated water and leachate from the site. In case of a composting plant treating green waste only, the competent authority may decide that this provision does not apply, treat the contaminated water and leachate collected from the treatment site including liquor from an anaerobic digestion plant to the appropriate standard required for their discharge. 3. Control of odour Measures shall be taken to control odour emissions from those biological treatment plants located near dwellings and processing fermentable biodegradable waste. Plants producing less than 100 tonnes of compost (fresh weight) per year or treating only green waste may be exempted from the obligation of odour emission control. The efficiency of the technical systems for the treatment of the odour shall be assessed following the CEN proposed method of dynamic olfactometry [CEN/TC 264/ WG 2 Odours, Odour concentration measurement by dynamic olfactometry ] and shall achieve an abatement of exhaust air to less than 300 OU/m³ (odour units). 4. Nuisance and hazards Measures shall be taken to minimise nuisances and hazards arising from the treatment plant through: emissions of dust, wind-blown materials, noise and traffic, birds, vermin and insects, formation of aerosols, and 16

17 fires. The treatment plant shall be equipped so that dirt originating from the site is not dispersed onto public roads and the surrounding land. 17

18 ANNEX VI General requirements for biogas use (1) When biogas is used as a fuel in internal combustion engines, the following emission limits shall be complied with: Parameter Unit Limit value Dust mg/m³ 5 NO x mg/m³ 200 SO 2 mg/m³ 100 CO mg/m³ 100 H 2 S mg/m³ 5 HCl mg/m³ 20 HF mg/m³ 5 Pb + Zn +Cr mg/m³ 5 As + Co + Ni mg/m³ 1 Cd mg/m³ 0.1 Hg mg/m³ 0.1 PCDD/F ng TE/m³ 0.1 O 2 % 3 (2) The above-mentioned parameters (excepted PCCD/F) shall be measured once a month in first three months of operation of the combustion engine and every year thereafter (PCCD/F every two years). (3) To prevent the formation of dioxins, the concentration in biogas of total halogenated hydrocarbons (AOX) shall be lower than 150 mg/m³. (4) Biogas that cannot be used on-site or upgraded to natural gas quality shall be flared. When flaring biogas, the outlet temperature of the flue gas shall be at least 900 C and the residence time 0.3 seconds. The maximum concentration of sulphur compounds in biogas shall be 50 ppm or a removal efficiency of at least 98% shall be proven. (5) In case of upgrade of biogas to natural gas standards, the use of the upgraded biogas shall be subject to the Community provisions pertaining to natural gas transport and use. 18

19 (6) Community standards for the parameters listed in this Annex should be developed. Until these standards are approved, Member States may apply national standards and procedures. 19