elv - eu practice

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EU PRACTICE IN SETTING WASTEWATER EMISSION LIMITVALUES

R.C.Frost

March 2009

1 Introduction and scope

The processes of setting emission limit values (ELVs) for wastewater and treatedeffluent discharged to surface water have evolved over time in EU member statesand are now to a large extent similar. But it wasnt always the case. In the 1970sand 1980s the practice in a number of continental member states was to set standardtechnology-based ELVs to be achieved by all dischargers (within a sector) whilst theUK, for example, tended to set long-term ELVs based on an assessment of theassimilative capacity of the receiving water with shorter-term ELVs based on theachievable performance of existing facilities.

The usual approach nowadays is to set minimum technology-based ELVs exceptwhere considerations of objective surface water quality (SWQ) require furtherreduction in pollutant loads provided this is technologically feasible and the costsare considered not disproportionate. In practice, the concepts of proportionate anddisproportionate cost are usually impossible to apply with confidence; hence theconcepts of reasonable or unreasonable cost usually substitute for them, tacitly atleast, i.e. decisions on whether to adopt stricter standards are the subject ofqualitative judgement rather than quantitative determination.

With regard to technology-based standards for wastewater discharge to surfacewater, two EU Directives are of prime significance: the Urban Wastewater Treatment

Directive (UWTD) and the Integrated Pollution Prevention and Control (IPPC)Directive. Both are referenced in the Water Framework Directive (WFD).

UWTD sets minimum treatment standards to be met by urban wastewater treatmentplants and industrial activities that generate similar effluents. The minimum degreeof treatment to be given and the ELVs to be achieved, depend on the nature of thesurface water that a facility discharges to.

IPPC provides a framework for a comprehensive and integrated regulation of thoseindustrial sectors whose activities are potentially the most polluting. This includeswaste treatment. Industrial sectors that are subject to IPPC are prescribed in theDirective. Production capacity criteria apply to enterprises in some sectors; so thatinstallations whose capacities fall below the sector criterion are excluded from IPPC

control. IPPC embodies the fundamental concepts of Best Available Techniques(BAT) - which includes technology, equipment and operational practices - and BATassociated emission levels (BATAEL). BAT and BATAEL are described in a series ofBAT reference documents known as BREFs. Following from and technicaldiscussions with an industrial operator, regulatory officials set site-specific ELVswhich may be derived from BATAEL. The ELVs are included in the installationsIPPC authorisation (permit).

Subject to safeguards, many industrial activities generate wastewater that can bedischarged to urban sewers for combined treatment with wastewater from domesticand other sources. For much small-scale industry, some larger scale industries afterwastewater pre-treatment, and many trades this disposal route offers the best optionfor cost-effective management of their wastewater. But safeguards in the form oftrade effluent control (TEC) must be in place to protect the workers, physical

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infrastructure, treatment processes, effluent discharge arrangements and sludgedisposal routes employed by the water and sewerage operator.

The WFD identifies of group of 33 substances for which, subject to disproportionatecosts and technical infeasibility constraints, control may be required:

Priority Substances (PS) form the largest sub-set within the group. Theirconcentrations in surface water should be controlled so as to achieve specificSWQ standards defined in EU legislation. Member states should also ensurethere is no deterioration in surface water quality from the current position.

Priority Hazardous Substances (PHS) form a smaller sub-set Theirconcentrations in surface water should be controlled so as to achieve specificSWQ standards defined in EU legislation. Member states must then (i)ensure no deterioration from the current position and (ii) to eliminate allemissions and discharges to water.

Practice in EU member states on the above issues is summarised and illustrated in

the following sections, using selected published information as far as possible.

2 Urban Wastewater Treatment Directive 91/271/EEC

2.1 Scope

Adopted in 1991, the UWTD requires that urban and similar wastewaters be treatedto minimum levels prior to discharge to surface water. This applied throughout theEU member states though, where needed, existing and new member states wereallowed periods of several years to catch up with the minimum requirements. Theapplication of the UWTD to a specific urban wastewater discharge depended (anddepends) on the population equivalent (p.e.) of the urban catchment and the nature

of the receiving water - see Section 2.2. The Directive also requires the regulation ofbiodegradable wastewater discharged to surface water from industrial plants inspecific sectors - see Section 2.3 - where the wastewater from a plant represents ap.e. of 4 000 or more. Relevant definitions of terms are:

'urban waste water' means domestic waste water or the mixture of domesticwaste water with industrial waste water and/or run-off rain water;

'domestic waste water' means waste water from residential settlements andservices which originates predominantly from the human metabolism andfrom household activities;

'industrial waste water' means any waste water which is discharged from

premises used for carrying on any trade or industry, other than domesticwaste water and run-off rain water;

'collecting system' means a system of conduits which collects and conductsurban waste water;

'1 p.e. (population equivalent)' means the organic biodegradable load havinga five-day biochemical oxygen demand (BOD5) of 60 g of oxygen per day.Loads expressed in p.e. shall be calculated on the basis of the maximumaverage weekly load entering a (collecting system and) treatment plant duringthe year, excluding unusual situations such as those due to heavy rain;

'primary treatment' means treatment of urban waste water by a physical

and/or chemical process involving settlement of suspended solids, or otherprocesses in which the BOD5of the incoming waste water is reduced by at

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least 20 % before discharge and the total suspended solids of the incomingwaste water are reduced by at least 50 %;

'secondary treatment' means treatment of urban waste water by a processgenerally involving biological treatment with a secondary settlement or otherprocess in which the requirements established in Table B.2 are respected;

'eutrophication' means the enrichment of water by nutrients, especiallycompounds of nitrogen and/or phosphorus, causing an accelerated growth ofalgae and higher forms of plant life to produce an undesirable disturbance tothe balance of organisms present in the water and to the quality of the waterconcerned;

sensitive area means a water body that falls into one of the following groups:(a) natural freshwater lakes, other freshwater bodies, estuaries and coastalwaters which are found to be eutrophic or which in the near future maybecome eutrophic if protective action is not taken Annex II of the Directivegives factors to take into account; (b) surface freshwaters intended for theabstraction of drinking water which could contain more than the concentration

of nitrate laid down under the relevant provisions of Council Directive75/440/EEC of 16 June 1975 if action is not taken; (c) areas where furthertreatment than that prescribed in Article 4 of this Directive is necessary to fulfilCouncil Directives.

2.2 Application of UWTD to Urban WWTPs

The UWTD applies to wastewater discharges to all surface waters. Table B.1 givesthe minimum specified levels of treatment for wastewater discharges to freshwater,which depend on (i) whether or not the freshwater body is a sensitive area and (ii)the wastewater p.e. For simplicity and relevance, the time periods that memberstates were allowed for meeting UWTD requirements are omitted.

Table B.1 Minimum Urban Wastewater Treatment Required Under UWTD

Wastewater p.e.Surface Water Designation

Freshwater Freshwater in Sensitive Area

2 000 to 10 000Secondary treatment see

Table B.2Secondary treatment see

Table B.2

10 000Secondary treatment see

Table B.2Secondary treatment see

Table B.3(1)

(1)Alternatively, requirements for individual plants need not apply in sensitive areas where it

can be shown that the minimum percentage of reduction of the overall load entering all urbanwaste water treatment plants in that area is at least 75 % for total phosphorus and at least 75% for total nitrogen.

UWTD also requires particular attention is paid to the sampling and analysis ofwastewater discharges to assess their compliance with the ELVs in Tables B.1 andB.2. Specifically:

WWTPs shall be designed or modified so that representative samples of theincoming wastewater and of treated effluent can be obtained before dischargeto receiving waters

Flow-proportional or time-based 24-hour samples shall be collected at thesame well-defined point in the outlet and if necessary in the inlet of thetreatment plant in order to monitor compliance

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Good international laboratory practices aiming at minimizing the degradationof samples between collection and analysis shall be applied

Compliance with the ELV is assessed at the 95 percentile confidence level the UWTD provides look-up tables specifying the maximum permissiblenumber of failures consistent with 95 percentile compliance. The number of

permissible failures varies non-linearly with the number of samples analysedduring the year. The annual number of samples noted in these look-up tablesranges from 4-7 to 351-365.

Table B.2 Minimum UWTD Secondary Treatment Performance

Values for limiting concentration or the percentage of reduction shall apply

ParameterLimiting

ConcentrationMinimum % Load

Reduction(1)

BOD5at 20 C

Biochemical oxygen demand without

nitrification(3,6)

25 mg/l O2 70 - 90

COD (Chemical oxygen demand)(4)

125 mg/l O2 75

Total suspended solids(5, 6)

35 mg/l 90(2)

(1)Reduction in relation to the influent load

(2)This requirement is optional

(3)Reference Method of Measurement: Homogenized, unfiltered, undecanted sample:

determination of dissolved oxygen before and after five-day incubation at 20 C 1 C, incomplete darkness. Addition of a nitrification inhibitor(4)

Reference Method of Measurement: Homogenized, unfiltered, undecanted sample:

potassium dichromate(5)

Reference Method of Measurement: Filtering of a representative sample through a 0.45m filter membrane. Drying at 105 C and weighing Or Centrifuging of a representativesample (for at least five minutes with mean acceleration of 2 800 to 3 200 g), drying at 105C and weighing(6)

Urban waste water discharges to waters situated in high mountain regions (over 1 500 mabove sea level) where it is difficult to apply an effective biological treatment due to lowtemperatures may be subjected to treatment less stringent than that prescribed aboveprovided that detailed studies indicate that such discharges do not adversely affect theenvironment. Table 1 of Annex 1 of the UWTD defines the relaxed limits

Table B.3 Additional Minimum UWTD Treatment Performance for aDischarge to a Sensitive Area

One or both parameters may be applied depending on the local situation.The values for concentration or for the percentage of reduction shall apply.

Wastewater p.e. ParameterLimiting

ConcentrationMinimum % Load

Reduction(1)

10 000 to 100 000Total Phosphorus

(3)

2 mg/l P 80

100 000 1 mg/l P 80

10 000 to 100 000Total Nitrogen

(2,3)

15 mg/l N(4)

70 - 80

100 000 10 mg/l N(4)

70 - 80

(1)Reduction in relation to the influent load

(2)This requirement is optional(3)

Reference Method of Measurement: Molecular absorption spectrophotometry

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(4)Alternatively, the daily average must not exceed 20 mg/l N. This requirement refers to a

water temperature of 12 C or more during the operation of the biological reactor of thewaste water treatment plant.

Taken from the EUs 1998 UWTD implementation review report, Figure B.1 belowshows the planned capacity growth for collecting systems and treatment plants overa thirteen-year period. This covered all 14 member states at that time. Collecting

systems capacity was planned to increase by 22 % and treatment capacity by 69 %over this period.

Figure B.1 Planned Development of Collecting Systems and TreatmentPlants (1 000 p.e.)

It may be noted that in Germany, the implementation of the UWTD necessitated amajor upgrading and expansion of the wastewater infrastructure and triggered verylarge investments. The problems connected with implementation in the new Lnderof eastern Germany were particular severe and of relevance. Similar to the situationin the EECCA, the wastewater infrastructure in the new Lnder was in such a

desolate condition immediately after German reunification that some of the existingsewage disposal systems could not even be rehabilitated. Cost-effective solutionswere therefore sought in order to contain the immense costs required forredevelopment. The efficient upgrading of wastewater collection and treatmentsystems in compliance with UWTD meant targeting financial resources carefully andmore economically in the water protection sector and avoiding local planningmistakes and measures that were regionally uncoordinated.

2.3 Application of UWTD to Industry

Article 11 of UWTD requires that discharges of industrial waste water into collectingsystems and urban waste water treatment plants is subject to prior regulations and/or

specific authorizations by the competent authority or appropriate body, i.e. it requiresthat industrial discharges to sewer be subjected to trade effluent control (TEC). TheTEC approaches adopted by selected authorising bodies in the United Kingdom issummarised in Section 5. Article 11 also states that the (TEC) regulations and/orspecific authorization shall satisfy the following requirements:

protect the health of staff working in collecting systems and treatment plants

ensure that collecting systems, waste water treatment plants and associatedequipment are not damaged

ensure that the operation of the waste water treatment plant and thetreatment of sludge are not impeded

ensure that discharges from the treatment plants do not adversely affect theenvironment, or prevent receiving water from complying with other

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Community Directives

ensure that sludge can be disposed of safety in an environmentallyacceptable manner.

Article 13 of UWTD refers to biodegradable industrial wastewater from plants that (i)belong to the industrial sectors listed below and (ii) (each) represent a wastewaterload of 4 000 p.e. or more. It requires that such wastewater, unless discharged tourban WWTPs, when it would be subject to TEC (see above), shall before dischargerespect conditions established in regulations and/or specific authorization by thecompetent authority or appropriate body. Unlike for urban wastewater discharges, nospecific minimum ELVs are laid down but it would be reasonable to apply the sameor similar ELVs as given in Tables B.2 and B.3. The sectors to which Article 13applies are:

Milk-processing

Manufacture of fruit and vegetable products

Manufacture and bottling of soft drinks

Potato-processing

Meat industry

Breweries

Production of alcohol and alcoholic beverages

Manufacture of animal feed from plant products

Manufacture of gelatine and of glue from hides, skin and bones

Malt-houses

Fish-processing industryIn a 1998 implementation review (7 years after adoption), the EU reported that:

only a few Member States had taken into consideration the threshold of 4 000p.e. Most stipulate in their laws that all discharges of industrial waste watermust, whatever their size, be subject to prior regulations and/or specificauthorisations

regarding the stipulation in paragraph 2 of Article 13 that requirements shouldbe appropriate to the nature of the industry concerned: Austria, Germany,France and Flanders in Belgium incorporate emission standards into theirlaws which vary according to the nature of the industry; the United Kingdom,

Finland, Ireland, the Netherlands, Denmark, Sweden and Luxembourg optedto determine emission standards on a case-by-case basis for each industrialsite, taking account of the principle of the best available technologies (BAT)when issuing discharge authorisations. In Greece, Italy and Portugal,national legislation did not define emission standards in relation to theindustry concerned and the authorisations issued were not based on theprinciple of BAT. Spain had not completed the process of transposing theprovisions of Article 13.

In conclusion, the Commission considered that nine Member States had adoptedprovisions in accordance with Article 13 of the directive. Austrian legislation wasdeemed to be not in conformity in that it did not cover all the industrial sectorsspecified in the directive. Italy had not transposed the directive. Checks were inprogress regarding Greece, Portugal, Belgium and Spain.

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3 Industry IPPC and Princip les of BAT3.1 Integrated Pollution Prevention and Control Direct ive (IPPC)

96/61/EC

Adopted in 1996, the IPPC Directive is concerned with industrial installations whosepotential for causing pollution is significant. Table B.4 lists the industrial activitiesand, where they apply, the threshold capacities or throughputs of installations subjectto IPPC. IPPC applies an integrated approach to pollution prevention, control andpermitting of installations. Releases to water, air and land are considered together inthe authorisation; all appropriate preventive measures are required to be takenagainst pollution, in particular through application of best available techniques (BAT);

and IPPC requires that no significant pollution is caused. Relevant definitionsinclude:

'substance` means any chemical element and its compounds, with theexception of radioactive substances within the meaning of Directive80/836/Euratom (1) and genetically modified organisms within the meaning ofDirective 90/219/EEC (2) and Directive 90/220/EEC (3);

'pollution` means the direct or indirect introduction as a result of humanactivity, of substances, vibrations, heat or noise into the air, water or landwhich may be harmful to human health or the quality of the environment,result in damage to material property, or impair or interfere with amenities andother legitimate uses of the environment;

'installation` means a stationary technical unit where one or more Annex-1activities listed below are carried out, and any other directly associatedactivities which have a technical connection with the activities carried out onthat site and which could have an effect on emissions and pollution;

emission` means the direct or indirect release of substances, vibrations, heator noise from individual or diffuse sources in the installation into the air, wateror land;

'emission limit values` means the mass, expressed in terms of certain specificparameters, concentration and/or level of an emission, which may not beexceeded during one or more periods of time. Emission limit values may also

be laid down for certain groups, families or categories of substances, inparticular for those listed in Annex III.

The emission limit values for substances shall normally apply at the pointwhere the emissions leave the installation, any dilution being disregardedwhen determining them. With regard to indirect releases into water, the effectof a water treatment plant may be taken into account when determining theemission limit values of the installation involved, provided that an equivalentlevel is guaranteed for the protection of the environment as a whole andprovided this does not lead to higher levels of pollution in the environment,without prejudice to Directive 76/464/EEC or the Directives implementing it;

'environmental quality standard` means the set of requirements which must

be fulfilled at a given time by a given environment or particular part thereof, asset out in Community legislation;

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'competent authority` means the authority or authorities or bodies responsibleunder the legal provisions of the Member States for carrying out theobligations arising from this Directive;

'permit` means that part or the whole of a written decision (or several suchdecisions) granting authorisation to operate all or part of an installation,

subject to certain conditions which guarantee that the installation complieswith the requirements of this Directive. A permit may cover one or moreinstallations or parts of installations on the same site operated by the sameoperator;

(a) 'change in operation` means a change in the nature or functioning, or anextension, of the installation which may have consequences for theenvironment;

(b) 'substantial change` means a change in operation which, in the opinion ofthe competent authority, may have significant negative effects on humanbeings or the environment;

'best available techniques` means the most effective and advanced stage inthe development of activities and their methods of operation which indicatethe practical suitability of particular techniques for providing in principle thebasis for emission limit values designed to prevent and, where that is notpracticable, generally to reduce emissions and the impact on the environmentas a whole:

'techniques` shall include both the technology used and the way in which theinstallation is designed, built, maintained, operated and decommissioned

'available` techniques means those developed on a scale which allowsimplementation in the relevant industrial sector, under economically andtechnically viable conditions, taking into consideration the costs and

advantages, whether or not the techniques are used or produced inside theMember State in question, as long as they are reasonably accessible to theoperator

'best` means most effective in achieving a high general level of protection ofthe environment as a whole

'operator means any natural or legal person who operates or controls theinstallation or, where provided for in national legislation, to whom decisiveeconomic power over the technical functioning of the installation has beendelegated

As indicated in Table B.4, the range of industrial activities coming under the IPPC

regime in EU member states is considerable. The application of BAT lies at the heartof IPPC and descriptive guidance on BAT in each industrial sector and sub-sector isprovided in a series of BAT Reference documents normally referred to as BREFs.All BREFs are freely available in English language (only) on the website of theEuropean IPPC Bureau (http://eippcb.jrc.es). The first BREFs became available afew years after the Directive was adopted. The final BREF of this, the first round,appeared in 2006. A process of revision and update to reflect technologicaladvances is currently in place.

Industry was not required to change overnight. Existing installations had severalyears to adapt to the new requirements: new installations were expected to applyBAT in their applications. Provision was also made for the application of BAT whenan existing installation was modified significantly.
http://eippcb.jrc.es/http://eippcb.jrc.es/


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Table B.4 Industrial Installations Subject to IPPC Directive 96/61/EC

The threshold values given below generally refer to production capacities or outputs. Where an operator carries out ssubheading in the same installation or on the same site, the capacities of such activities are added together.

Category Sector Sub-Sector

1. Energy industries 1.1 Combustion installations -

1.2. Mineral oil and gas refineries -

1.3. Coke ovens -

1.4. Coal gasification and liquefaction plants -

2. Production andprocessing of metals

2.1. Metal ore (including sulphide ore) roastingor sintering installations

-

2.2. Production of pig iron or steel (primary orsecondary fusion) including continuous casting

-

2.3. Processing of ferrous metals a) Hot-rolling mills

(b) Smitheries using hammers

(c) Application of protective fused metalcoats

2.4. Ferrous metal foundries -

2.5. Installations (a) production of non-ferrous crudemetals from ore, concentrates orsecondary raw materials bymetallurgical, chemical or electrolyticprocesses

(b) smelting, including the alloyage ofnon-ferrous metals, including recoveredproducts, (refining, foundry casting, etc.)

2.6. Surface treatment of metals and plasticmaterials using an electrolytic or chemicalprocess

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3. Mineral industry 3.1 production of cement clinker and lime Production of cement clinker in rotarykilns

Production of lime in rotary kilns or otherfurnace

3.2. Production of asbestos and themanufacture of asbestos-based products

-

3.3. Manufacture of glass including glass fibre -

3.4. Melting mineral substances including theproduction of mineral fibres

-

3.5. Manufacture of ceramic products by firing:in particular roofing tiles, bricks, refractorybricks, tiles, stoneware or porcelain

-

4. Chemical industry

industrial scaleproduction by processingsubstances or groups ofsubstances listed in 4.1to 4.6

4.1. Basic organic chemicals, such as: (a) simple hydrocarbons (linear or cyclic,

saturated or unsaturated, aliphatic oraromatic)

(b) oxygen-containing hydrocarbonssuch as alcohols, aldehydes, ketones,carboxylic acids, esters, acetates,ethers, peroxides, epoxy resins

(c) sulphurous hydrocarbons

(d) nitrogenous hydrocarbons such asamines, amides, nitrous compounds,nitro compounds or nitrate compounds,nitriles, cyanates and isocyanates

(e) phosphorus-containing hydrocarbons

(f) halogenic hydrocarbons

(g) organometallic compounds

(h) basic plastic materials (polymerssynthet-ic fibres and cellulose-based


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fibres)

4. Chemical industry -continued

(i) synthetic rubbers

(j) dyes and pigments

(k) surface-active agents andsurfactants

4.2 Basic inorganic chemicals, such as: (a) gases, such as ammonia, chlorine orhydrogen chloride, fluorine or hydrogenfluoride, carbon oxides, sulphurcompounds, nitrogen oxides, hydrogen,sulphur dioxide, carbonyl chloride

(b) acids, such as chromic acid,hydrofluoric acid, phosphoric acid, nitricacid, hydrochloric acid, sulphuric acid,oleum, sulphurous acids

(c) bases, such as ammoniumhydroxide, potassium hydroxide, sodiumhydroxide

(d) salts, such as ammonium chloride,potassium chlorate, potassiumcarbonate, sodium carbonate,perborate, silver nitrate

(e) non-metals, metal oxides or otherinorganic compounds such as calciumcarbide, silicon, silicon carbide

4.3. Production of phosphorous-, nitrogen- orpotassium-based fertilisers (simple or

compound fertilisers)

-

4.4. Production of basic plant health productsand of biocides

-

4.5. Installations using a chemical or biologicalprocess for the production of basicpharmaceutical products

-

4.6. Chemical installations for the production of -


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explosives

5. Wastemanagement

- see Directive text forcross-references to other

Directives

5.1. Installations for the disposal or recovery ofhazardous waste and the disposal of wasteoils see Directive text for further guidance

-

5.2. Installations for the incineration ofmunicipal waste

-

5.3. Installations for the disposal of non-hazardous waste - see Directive text for furtherguidance

-

5.4. Landfills excluding landfills of inert waste -

6. Other activities 6.1 Industrial plants for the production of: (a) pulp from timber or other fibrousmaterials

(b) paper and board

6.2. Plants for the pre-treatment (operationssuch as washing, bleaching, mercerisation) ordyeing of fibres or textiles

-

6.3. Plants for the tanning of hides and skins -

6.4 (Food processing) (a) Slaughterhouses

(b) Treatment and processing intendedfor the production of food products from:

- animal raw materials (other than milk)

- vegetable raw materials

(c) Treatment and processing of milk


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3.2 IPPC Permitt ing and ELVs

3.2.1 Principles

Articles 9, 10 and 18 of the Directive refer to the conditions of an IPPC permit andsetting ELVs. Paragraphs 3, 4 and 5 of Article 9 state in part that:

Para. 3: The permit shall include ELVs for pollutants, in particular, those listedin Annex III likely to be emitted from the installation concerned in significantquantities, (i.e. ELVs do not have to set for all the parameters listed below,only if the substances are likely to be emitted in significant quantities) havingregard to their nature and their potential to transfer pollution from oneenvironmental medium to another. Where appropriate, limit values may besupplemented or replaced by equivalent parameters or technical measures.The Annex III indicative list of main polluting substances to be taken intoaccount if relevant for fixing emission limit values for releases to water are:

Organohalogen compounds and substances which may form suchcompounds in the aquatic environment

Organophosphorus compounds

Organotin compounds

Substances and preparations which have been proved to possesscarcinogenic or mutagenic properties or properties which may affectreproduction in or via the aquatic environment

Persistent hydrocarbons and persistent and bioaccumulable organic toxicsubstances

Cyanides

Metals and their compounds Arsenic and its compounds

Biocides and plant health products

Materials in suspension

Substances which contribute to eutrophication (in particular, nitrates andphosphates)

Substances which have an unfavourable influence on the oxygen balance(and can be measured using parameters such as BOD, COD, etc.).

Para. 4. Without prejudice to Article 10, the ELVs and the equivalent

parameters and technical measures referred to in paragraph 3 shall be basedon the best available techniques, without prescribing the use of any techniqueor specific technology, but taking into account the technical characteristics ofthe installation concerned, its geographical location and the localenvironmental conditions. In all circumstances, the conditions of the permitshall contain provisions on the minimisation of long-distance or transboundarypollution and ensure a high level of protection for the environment as a whole.

Para. 5: The permit shall contain suitable release monitoring requirements,specifying measurement methodology and frequency, evaluation procedureand an obligation to supply the competent authority with data required forchecking compliance with the permit.

Article 10 refers to BAT and environmental quality standards, stating that: Where anenvironmental quality standard requires stricter conditions than those achievable by

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the use of BAT, additional measures shall in particular be required in the permit,without prejudice to other measures which might be taken to comply withenvironmental quality standards. This is the so-called combined approach.

Paragraph 1 of Article 18 provides the basis for the setting of ELVs at the Communitylevel, though this has procedure not been invoked. Paragraph 2 states in part that,

In the absence of Community emission limit values defined pursuant to para. 1), therelevant ELVs contained in (15) Directives referred to in Annex II shall be applied asminimum ELVs for the installations listed in the IPPC Directive (Table B.4). TheDirectives referred to include:

Directive 82/176/EEC on limit values and quality objectives for mercurydischarges by the chlor-alkali electrolysis industry

Directive 83/513/EEC on limit values and quality objectives for cadmiumdischarges

Directive 84/156/EEC on limit values and quality objectives for mercurydischarges by sectors other than the chlor-alkali electrolysis industry

Directive 84/491/EEC on limit values and quality objectives for discharges ofhexachlorocyclohexane

Directive 86/280/EEC on limit values and quality objectives for discharges ofcertain dangerous substances included in List 1 of the Annex to Directive76/464/EEC, subsequently amended by Directives 88/347/EEC and90/415/EEC amending Annex II to Directive 86/280/EEC

Directive 76/464/EEC on pollution caused by certain dangerous substancesdischarged into the aquatic environment of the Community

Directive 75/442/EEC on waste, as amended by Directive 91/156/EEC

Directive 91/689/EEC on hazardous waste3.2.2 Summary

In summary, therefore, the Directive envisaged that ELVs for wastewater dischargesto surface water from installations subject to IPPC would be set as follows:

According to the current state of technology BAT subject to defaultmaximum values where defined in other EU Directives

Stricter than BAT where surface water quality would otherwise becompromised

In practice, BAT is interpreted as taking into account the relation of costs and

benefits, hence measures going beyond BAT are usually regarded as breaching theproportionality principle. Certainly this is the view of the Federation of GermanIndustries (BDI), representing 35 industrial sector federations and 100 000 industrialenterprises that employ more than 8 million people. Commenting on a draft proposalto recast the IPPC Directive (and others) to form a unified Industrial EmissionsDirective, the BDI has sought specific assurance that quality standards and nationalemission ceilings will not lead to measures going beyond BAT (Reference: BDI(2007), Position Paper: Proposal of the Commission for a Directive on IndustrialEmissions (IPPC), Document No. D 0163, 24 October 2007. Available at: www.bdi-online.de). By implication, it is normal practice in Germany that ELVs which are setfor IPPC installations are not stricter than those achievable by BAT. The sameapproach applies in the United Kingdom.

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3.3 BAT an Introduction

3.3.1 Considerations when Determin ing BAT

Considerations to be taken into account generally or in specific cases whendetermining best available techniques, as defined in Article 2 (11) of the Directive,

bearing in mind the likely costs and benefits of a measure and the principles ofprecaution and prevention, are:

1. the use of low-waste technology

2. the use of less hazardous substances

3. the furthering of recovery and recycling of substances generated and usedin the process and of waste, where appropriate

4. comparable processes, facilities or methods of operation which have beentried with success on an industrial scale

5. technological advances and changes in scientific knowledge and

understanding6. the nature, effects and volume of the emissions concerned

7. the commissioning dates for new or existing installations

8. the length of time needed to introduce the best available technique

9. the consumption and nature of raw materials (including water) used in theprocess and their energy efficiency

10. the need to prevent or reduce to a minimum the overall impact of theemissions on the environment and the risks to it

11. the need to prevent accidents and to minimise the consequences for the

environment12. the information published by the Commission pursuant to Article 16 (2) or

by international organisations.

The BREF documents and IPPC regulators therefore place great emphasis on theuse of at-source prevention of pollutant generation or where, that is not feasible, atminimising pollutant generation at-source. So a major focus is on the practices andtechniques employed within the industrial production facility this is in distinctcontrast to the older approach of simply regulating the emission to water (or to air orland). The introduction of IPPC and BAT thus requires a significant expansion inprofessional capacity of the regulatory staff that inspect installations, set and enforcepermits.

IPPC regards the treatment of wastewater (and other streams) prior to discharge assubsidiary to or supportive of the primary role played by applying preventive andminimisation techniques. But wastewater treatment is not ignored and BREFs giveguidance on good practice in this area also.

Potential techniques cover a wide range including the monitoring and management ofmaterial, water and energy use; operational good practice; retrofitting equipment toimprove the efficient use of materials, water and energy; investment in less pollutingproduction technologies; recycling of waste streams; replacement where possible ofhazardous substances with those that are more benign; and choosing effectivemethods for the treatment and disposal of the wastewater generated. BAT thereforecomprises a combination of at-source and end-of-pipe techniques. The later BREFs,

in particular, indicate the average level of emissions that an installation should beable to achieve through the application of BAT. This average value of emissions

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level is termed BATAEL (BAT associated emissions level). BATAEL is not the sametherefore as a binding ELV, though it may form a basis for determining the ELV for aninstallation.

3.4 BATAEL vs. ELV

The effluent from any system of industrial production and wastewater treatment willbe influenced by changes in raw material characteristics, fluctuations in productionlevel and efficiency and changes in the performance of the WWTP facility. Effluentquality is bound to be variable to some extent therefore. Actual effluent quality willvary around an average value. And if effluent quality is normally distributed, we mayexpect effluent quality to be worse than average for 50% of the time - the rest of thetime, we may expect effluent quality to be better than average. (The actualdistribution may be skewed to some extent, in which case we should refer to themedian rather than the average.) We shall assume a normal distribution for presentpurposes.

BATAEL represents average effluent quality and is determined empirically, i.e. from

the actual results measured at industrial installations. This being the case, it isirrational and incorrect to set an ELV as a maximum allowable concentration (PDK)equal to BATAEL. Instead, the ELV that is appropriate and consistent with BATAELis that level at which we can say that:

If sampling and analysis indicates that the ELV is satisfied for 95% of thetime then we can be reasonably confident (a) that average effluent quality isconsistent with the BATAEL and (b) that BAT is being applied.

Figure B.2 illustrates the concept, showing a distribution of effluent quality around anaverage value - BATAEL and showing the value of effluent quality which is met for95% of the time the ELV. In practice, ELVs are set by regulators following serioustechnical negotiations with the operator of an existing or proposed installation.

Figure B.2 Concept of BATAEL vs. ELV

95 percentile

Effluent

mg/l

BATAEL ELV

Since the value of BATAEL is determined empirically, its value depends on thespecific characteristics of an installation in a given sector. And since each installation

may be regarded as a unique situation, the reality is that a single BATAEL value isnot necessarily applicable to all installations in a sector. Nor by extension, is it

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necessarily valid to apply a single ELV to all installations within a given sector or sub-sector. Hence BREF documents commonly contain a range of BATAEL values. Itshould also be noted that as IPPC seeks to prevent or minimise pollutant loadreleases, BATAEL values are commonly given as specific pollutant loads (e.g. kgpollutant per tonne of product, m3 wastewater per tonne product etc). If indicativeBATAEL concentration values are not given they may be calculated from the loadvalues.

Commenting on a draft proposal to recast the IPPC Directive (and others) to form aunified Industrial Emissions Directive, the IPPC Alliance of (12) energy intensiveindustries whose constituent fims employed over 7.2 million people provided anexample to illustrate the issue (full submission available at: www.eurofer.org). FigureB.3 illustrates the case where two installations apply the same techniques but, due toother factors such as raw materials, new vs existing installation etc - averageemissions differ. Different ELVs apply, therefore.

Figure B.3 Environmental Performances and ELVs of Two InstallationsApplying the Same Technique

Setting technology-based ELVs for industrial installations is clearly not an easy task,therefore. It requires that both the industrial operator and the regulator or permitissuing/enforcement authority have (a) access to meaningful monitoring andperformance data (b) an in-depth understanding of technical issues and (c) can cometo a reasonably common accord on setting an ELV that may be technicallychallenging this may appear especially demanding initially as major change might

be needed to achieve the desired improvement in environmental performance - but isachievable. Though not an easy procedure, this is the basis on which ELVs are set

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for IPPC installations in EU member states. It requires that permit issuers/enforcersapply judgement and may involve incremental change, potentially including thetightening of ELVs over time as experience and knowledge accumulates.

4 Specif ic Industr ial Sectors BATAEL and Selected ELVs

4.1 Scope

The specific ELVs set for an IPPC installation are or should be made available forpublic information. In the UK, for example, public registers of discharge consents aremade available as public records, open for inspection on appointment at a local officeof the Environment Agency for England and Wales.

BREFs dont contain the ELVs as such, which are set locally, but may contain theBATAEL values agreed by the EIPPCB through the Seville process. BATAELrepresents the typical output from an installation, i.e. after BAT is applied which mayinclude wastewater pre-treatment of treatment. The Seville process entails dialoguebetween representatives of the national regulators, industry and other IPPC

stakeholders; the preparation of draft BREFs; and further consultation and dialoguebefore the BREFs are finalised and adopted.

Though all the BREFs offer a high level of description of the techniques involved inBAT, not all are forthcoming regarding BATAEL values: the later BREFs tend toprovide more detail than did the earlier ones. In due course it may be expected thatthe revised BREFs will provide more comprehensive performance data.

Abstracted from the adopted BREF documents; Tables B.5 to B.11 give BATAELvalues for four selected industrial sectors, the date of BREF adoption is given inparenthesis. They serve as an illustration: some BATAEL values are given asconcentrations, other as loads; some are given as single values, some as range andsome as upper limit values. Potential provision is made for the ELVs for specific

installations in the sector to be inserted from public registers at a later date. Thesectors covered here are:

Food and drink manufacture

Paper making including pulping of recycled paper

Iron and steel coke production

Intensive rearing of pigs.

4.2 Food and Drink Sector Including Milk Processing (2006)

Table B.5 BATAEL and Selected ELVs: Food and Drink Sector

Discharge Parameter BATAEL

ELVs for Selected Installations

Plant A

UK

Plant B

Germany

Plant C

Netherlands

BOD5mg/l 25

COD mg/l 125

TSS mg/l 50

pH value 6 - 9

Oil and grease mg/l 10

Total nitrogen 10

Total phosphorus 0.4 to 0.5

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Note:Better levels of BOD5 and COD can be obtained. It is not always possible or cost effective toachieve the total nitrogen and phosphorus levels shown, in view of local conditions.

Additional BAT for dairies and specific BAT for producing market milk, powderedmilk, butter, cheese and ice-cream address water consumption, energy consumptionand waste prevention. Table B.6 gives the range of consumption and emission

levels indicative of levels that can be achieved by applying in-process BAT they arebased on reported achieved levels. The ranges reflect a variety of operatingconditions. Water consumption and waste water emission levels may vary due to,e.g. different product portfolios, batch sizes and cleaning systems. The waste wateremission level may be lower compared to the water consumption level becausemany dairies measure the intake of cooling water, but discharge it unmeasured. Inwarm climates, more water may be lost due to evaporation.

Table B.6 Addit ional Consumption and Discharge Levels Typical for MilkProcessing

Milk ProcessesEnergy

ConsumptionWater

ConsumptionWastewaterDischarge

Production of market milk from 1litre of received milk

0.07 - 0.2 kWh/l 0.6 1.8 l/l 0.8 1.7 l/l

Production of milk powder from 1litre of received milk

0.3 0.4 kWh/l 0.8 1.7 l/l 0.8 1.5 l/l

Production of 1 kg of ice-cream 0.6 2.8 kWh/kg 4.0 5.0 l/kg 2.7 4.0 l/kg

4.3 Paper and Board Manufactur ing (2001)

Table B.7 gives the BATAEL load values for integrated recovered paper mills, i.e.recovered paper (and cardboard) processing and papermaking are carried out at thesame site. The BATAEL values refer to yearly averages and are presented

separately for processes with and without deinking. Wastewater flow is based on theassumption that cooling water and other clean water are discharged separately, i.e.the values given are for process wastewater only, excluding cooling waterdischarges. Table B.8 gives the equivalent concentration values for (a) integratedRCF paper mills without deinking, assuming the achievable specific wastewaterdischarge volume.

Table B.7 BATAEL Load Values for Integrated Recovered Paper mil ls

Load Parameter

Integrated RCF Paper Mill

(a) Without de-inkinge.g. carton-board etc

(b) With de-inking e.g.newsprint, printing and

writing paper

(c) Tissue mills

Flow m3/t (dry) 7 8 - 15 8 - 25

BOD5kg/t (dry) 0.05 0.15 0.05 0.2 0.05 0.5

COD kg/t (dry) 0.5 1.5 2 - 4 2 - 4

TSS kg/t (dry) 0.05 0.15 0.1 0.3 0.1 0.4

Total N kg/t (dry) 0.02 0.05 0.05 0.1 0.05 0.25

Total P kg/t (dry) 0.002 0.005 0.005 0.01 0.005 0.015

AOX(1)

kg/t (dry) 0.005 0.005 0.005

(1) Adsorbable organic halogenated compounds

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Table B.8 BATAEL and Selected ELVs: Integrated Recovered Paper Mills

(a) Integrated recovered f ibre (RCF) paper mil ls w ithout deinking



Plant A

UK

Plant B

Germany

Plant C

NetherlandsBOD5 mg/l 7 - 21

COD mg/l 70 - 210

TSS mg/l 7 - 21

Total N mg/l 3 - 7

Total P mg/l 0.3 0.7

AOX(1)

mg/l 0.7

(1)Adsorbable organic halogenated compounds

Table B.9 gives the BATAEL load values for non-integrated paper mills. They are

presented for three types of paper product though the differences between the papergrades are not distinct. The BATAEL values refer to yearly averages. Again,wastewater flow is based on the assumption that cooling water and other clean waterare discharged separately, i.e. the values given are for process wastewater only,excluding cooling water discharges.

Table B.9 BATAEL Load Values for Non-Integrated Paper mil ls

Load Parameter

Products of Non-Integrated RCF Paper Mills

(a) Uncoated finepaper

(b) Coated fine paper (c) Tissue

Flow m3/t (paper) 10 - 15 10 - 15 10 25

BOD5kg/t (paper) 0.15 0.25 0.15 0.25 0.15 0.4

COD kg/t (paper) 0.5 2 0.5 1.5 0.4 1.5

TSS kg/t (paper) 0.2 0.4 0.2 0.4 0.2 0.4

Total N kg/t (paper) 0.05 0.2 0.05 0.2 0.05 0.25

Total P kg/t (paper) 0.003 0.01 0.003 0.01 0.003 0.015

AOX(1)

kg/t (paper) 0.005 0.005 0.001

(1)Adsorbable organic halogenated compounds

4.4 Coke Production (2001)

Table B.10 gives BATAEL concentrations for wastewater from coking plants afterbiological wastewater treatment with integrated nitrification and denitrification. Theconcentration values are based on a specific wastewater flow of 0.4 m3per tonne ofcoke.

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Table B.10 BATAEL and Selected ELVs: Coke Production



Plant A

UK

Plant B

Germany

Plant C

Netherlands

COD removal

90%Sulphide mg/l 0.1

PAH mg/l(1)

0.05

CN mg/l 0.1

Phenols mg/l 0.5

Sum of NH4+, NO2

-and NO3

-

nitrogen30

Suspended solids 40

(1) the 6 Borneff substances: Fluoranthene (CAS number 206-44-0), benzo(a)pyrene(CAS number 50-32-8), benzo(b)fluoranthene (CAS number 205-99-2),

benzo(k)fluoranthene (CAS number 207-08-9), benzo(g,h,i)perylene (CAS number191-24-2) and indeno(1,2,3-cd)pyrene (CAS number 193-39-5). See Section 6 also.

4.5 Intensive Rearing of Poultry and Pigs (2003)

Table B.11 gives BATAEL values for effluent following the biological treatment of pigmanure at large farms.

Table B.11 BATAEL and Selected ELVs: Biological Treatment of Pig Manure



Plant A

UK

Plant B

Germany

Plant C

Netherlands

BOD5mg/l 90

COD mg/l 1 800

P mg/l(1)

260

N Kjmg/l 80

5 Industrial Wastewater Discharges to Sewer UK Practiceof Trade Effluent Control

5.1 Objectives

Section 2.2 notes the requirement under the UWTD for EU member states to exertregulatory control over the discharge of industrial wastewaters to sewer. The tradeeffluent control (TEC) practice of water and sewerage companies in England andWales is used here to illustrate TEC. These companies are mandated underlegislation (Water Act 1991) to regulate trade effluent discharges to their seweragesystems. Companies such as Welsh Water and United Utilities publish guidance andapplication forms see, respectively, http://www.dwrcymru.com/English andhttp://www.unitedutilities.co.uk for the use of proposed dischargers. In addition tomeeting the objectives outlined in Section 2.2, setting trade effluent consents hastwo other purposes. In total they are to

protect the health of staff working in collecting systems and treatment plants

ensure that collecting systems, waste water treatment plants and associatedequipment are not damaged

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ensure that the operation of the waste water treatment plant and thetreatment of sludge are not impeded

ensure that discharges from the treatment plants do not adversely affect theenvironment, or prevent receiving water from complying with otherCommunity Directives

ensure that sludge can be disposed of safety in an environmentallyacceptable manner.

prevent an unacceptable frequency of storm sewage discharges towatercourses

ensure that the discharger pays an appropriate charge for the reception,conveyance, treatment and disposal of his effluent.

5.2 Procedures

Each water and sewerage company operates its own procedures but essentially theycomprise the steps indicated in Figure B.4.

Figure B.4 Trade Effluent Control - Application to Discharge to Sewer

An industrial operator or trader is required to complete a number of forms and submita site drainage plan to the sewerage operator in the Stage 1 pre-application. Theseforms are designed to help inform the sewerage operator as to the exact location of

the proposed discharge, the nature of the activities undertaken relevant to effluentvolume and composition, and the substances likely to be present in the effluentabove background concentrations in the water supply. A sewerage company makingan assessment of a Stage 1 pre-application will take into account:

The nature and concentration of the likely constituents of the trade effluentand their potential negative effects on the sewerage system. If consideredacceptable, limits will be set in the consent for each constituent.

Additional analytical information may be requested at this stage.

If any of the constituents declared are prescribed substances under IPPClegislation and are likely to be present in significant quantities then theapplication will be referred to the national competent authority (EnvironmentAgency in England and Wales), who may impose conditions to be included inthe consent

Rationalisation and/or treatment of trade effluent may be required before thesewerage company is able to grant permission to discharge to the publicsewers. For example:

o Drainage amendments may be required to combine a number of tradeeffluent sources into a single waste stream (for monitoring and controlpurposes), or an

o Effluent pre-treatment plant may have to be installed and maintainedin order to remove or reduce certain constituents in the trade effluent

Applicant:Stage1Forms

Applicant:

Stage2Complete&SubmitTEC

Notice

Sewerage Co:GrantorSewerage Co:Assessmentand

DraftingofTECNotice

DeclineTEConsent

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If satisfied with the proposed discharge, the sewerage company will prepare a tradeeffluent notice for the applicant to sign and return with an application fee. The tradeefflunet notice is a formal request to discharge to the sewer and will stipulate:

Sampling point - the Consent requires that a designated trade effluentsampling point be provided through which only trade effluent may pass, that

is, no domestic sewage must be present. This point must be safe and easilyaccessible at all times.

Sampling equipment - in order to obtain accurate representation of the natureand composition of the trade effluent, there may be a requirement for thedischarger to supply and maintain equipment capable of sampling and / ormonitoring the trade effluent discharge.

Wastewater flow recording - it is necessary to be able to accurately determinethe volume and rate of flow of trade effluent passing into the public sewer.This may require the installation of an appropriate measuring device, capableof recording flow rate and totalised volumes of effluent entering the foul watersystem.

Self-monitoring - there may be a requirement for the discharger to carry outsome self-monitoring and keep such records to an auditable standard andmade available for inspection upon request.

Maximum flow rates and, where applicable, wastewater concentration limits.

After Consent is granted, the sewerage company will take compliance samples asappropriate to monitor for the relevant constituents of the effluent. The number ofmonitoring visits by the sewerage companys Trade Effluent Inspectors will bedetermined by the nature and volume of the trade effluent.

If required, they will take additional samples in order to obtain more

representative results for trade effluent billing purposes.

Samples may be analysed by an independent laboratory. The seweragecompanys Trade Effluent Officers will check each completed SampleAnalysis Report for compliance with the Consent conditions before forwardingto the discharger with comments. If necessary, a letter of Breach of Consentwill accompany the report, requesting information on the nature of the incidentand what remedial action is to be taken in future to prevent a recurrence.

Any queries about the detail of a Consent to Discharge may be raised withthe sewerage companys Area Trade Effluent Officer.

The consent granted will remain unchanged for a period of at least 2 years

(under the terms of the Water Industry Act 1991).

Breach of any conditions of a Trade Effluent Consent is a criminal offence and mayrender the discharger liable for prosecution by the water and sewerage company.

5.3 Commonly Imposed Restrictions on the Discharge ofIndustrial Effluent to Sewer

The following non-exhaustive list indicates the number of physical and chemicalparameters that a water and sewerage company may limit in a Trade EffluentConsent this list is taken from a publication of United Utilities, a company thatprovides water and wastewater services in the industrial north west of England.

Dependent on the nature of the industrial activity, the water and sewerage company

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might seek to set limits on other parameters not mentioned below. Any limit valuesgiven below are indicative and not prescriptive:

Ammonia

Ammonia can cause unsafe sewer atmospheres and toxicity problems inwatercourses.

Flammable Substances

Flammable substances or substances which can produce flammable or explosiveatmospheres will be prohibited or controlled to safe levels.

Hydrogen Cyanide

The limit is not greater than 1 mg/l. Hydrogen cyanide is toxic and can inhibittreatment processes.

Hydrogen Sulphide

The limit for substances that can produce hydrogen sulphide upon acidification is

normally 1 mg/l. Hydrogen sulphide is a toxic gas that can build up in the seweratmosphere, leading to hazardous working conditions. Hydrogen sulphide also has avery pungent odour which can cause smell nuisance.

Organic Load

Chemical oxygen demand and biological oxygen demand may be limited to preventoverloading of the wastewater treatment processes.

pH

The normal range of pH allowed is 6 to 10. Extremes of pH can lead to an unsafeworking environment, affect biological treatment systems and damage equipment.Low and high pH can result in damage to the materials of construction of the sewer

network.

Red Lis t Substances

These substances are controlled under international conventions. A list of thesesubstances is included in the preliminary document (Stage 1) and includes themetals cadmium and mercury, chlorinated solvents and a range of pesticides. Thesesubstances are persistent within the environment and can accumulate through thefood chain. They can also inhibit biological treatment processes.

Separable Oil and Grease

Separable oil and grease can build up within the sewer which can lead to smell

problems, blockages and subsequent foul flooding. Oil and grease can also build upon equipment such as pumps and cause operational difficulties at pumping stationsand treatment works.

Sulphate

Sulphate is normally limited to 1 000 mg/l because it can cause damage to concretestructures.

Suspended Solids

Suspended solids can cause siltation and blockages in the sewerage system.

Temperature

This is limited by statute to a maximum of 43.3 oC

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Toxic Metals

This group includes the metals; antimony, beryllium, chromium, copper, lead, nickel,selenium, silver, tin, vanadium and zinc. Metals can cause a range of problems. Thepresence of toxic metals can inhibit biological treatment processes and they mayaccumulate in the environment.

Volume

This parameter is normally limited to a number of cubic metres per 24 hour periodand a rate of discharge in litres per second.

5.4 Charging for Industrial Effluent Discharges to Sewer

Industry discharging effluent to public sewer pays the sewerage company accordingto a widely used formula (known for historical reasons as the Mogden formula). Thisformula has a number of cost-recovery elements:

A charge for the reception and conveyance of the effluent into and by thesewerage system

A charge for the preliminary (screening, grit removal) and primary treatment(sedimentation)

A charge for pumping and settlement of effluent during secondary (biological)treatment

A charge for secondary (biological) treatment excluding pumping andsettlement mainly this is for the aeration tanks, aeration and secondarysludge treatment and disposal

A charge for primary sludge treatment and disposal

Other charge elements may be added if the trade effluent constituentscontribute to the sewerage company incurring significant additional costs e.g.a industrial operator releasing wastewater containing significant quantities ofnitrogenous and phosphorus compounds to a WWTP discharging effluent todesignated sensitive area. The sewerage company would be required toprovide nutrient (N and P) removal prior to discharge and would include N-and P-related components in its charging structure.

The third and fourth charge elements above would be excluded if only preliminaryand primary sewage treatment were provided. The formula takes the general form:

C = R + V + B1+ B2(Ot/Os) + S (St/Ss)

Where:

R = Charge per cubic metre for reception and conveyance

V = Charge per cubic metre for preliminary and primary sewage treatment

B1= Charge per cubic metre for pumping and settlement during biologicaltreatment

B2= Charge per cubic metre for biological treatment (minus pumping andsettlement) and the treatment and disposal of biological sludge

S = Charge per cubic metre for primary sludge treatment and disposal

Os = One-hour settled COD of crude sewage (mg/l)

Ss = Average Suspended Solids of crude sewage (mg/l)

Ot = Average one-hour settled COD of trade effluent at pH 7 (mg/l)St = Average Suspended Solids of trade effluent at pH 7 (mg/l)

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The values of the charge components R, V, B1, B2 and S and of the standardstrength terms Os, Ot, Ss and St - vary from company to company according to theirparticular situation. Values for one of the sewerage companies in 2004/05 are givenbelow for illustration:

R /m3 0.131

V /m3 0.100

B1 /m3 0.015

B2 /m3 0.093

S /m3 0.079

Os mg/l 312

Ss mg/l 230

Two examples are given in Table B.12 to indicate (i) the influence that wastewaterdischarge strength has on the costs incurred and (ii) that upper limits on the content

of oxidisable components may be quite relaxed or not imposed at all dependent onthe capability of the urban WWTP to handle the discharge.

Table B.12 Illustrat ive Trade Effluent Charges

Assuming full treatment and taking the formula values given above

Parameter Plant 1 Plant 2

Volume in charging period (m3) 5 000 5 000

Ot

Chemical oxygen demand (mg/l)

500 3 000

St

Suspended solids (mg/l)

150 900

Charge for the period () 2 260 7 275

6 WFD Priority and Priority Hazardous Substances

For substances considered to be particularly hazardous the WFD requires MemberStates to meet (surface water) Environmental Quality Standards (EQSs) set by theEuropean Commission (in COM(2006)397 and most recently covered in a CommonPosition adopted by the Council). EQSs are set for the priority (PS) and priorityhazardous substances (PHS) identified in Table B.13:

i. Priority Substances: referred to as Annex X in the WFD. A water body will failGood Chemical Status if any of these EQSs are not complied with;

ii. Priority Hazardous Substances: these are a subset of PS. They aresubstances which are considered extremely harmful and, as well as achievingthe EQS, discharges, emissions and losses must cease or be phased out.

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Summary of WFD requirements for Priority Substances

RequirementPriority

substancesPriority hazardous

substances

Meet the proposed EQS by 2015

Progressive reduction of discharges, emissions andlosses (until EQS is achieved)

Cessation or phasing out of discharges, emissions andlosses (20 years from adoption of a proposal) X

However, the WFD allows less stringent, or alternative, objectives to be met where itwould be technically infeasible or disproportionately expensive to achieve theobjectives (by 2015). For example, exemptions may also apply to the objective ofaiming to cease emissions, discharges and losses of PHS and progressive reductionof discharges emissions and losses of Priority Substances on the grounds ofinfeasibility and disproportionate cost. As noted earlier, applying these concepts is

more a matter of judgement and interpretation than mechanistic quantification.

The competent authority in each member state is charged with implementing theWFD by developing River Basin Management Plans (RBMPs) and Programmes ofMeasures to set out the actions needed to meet EQSs and other WFD objectives. InEngland and Wales, the Environment Agency is charged with this responsibility and,in part fulfilment of this, has prepared a series of documents that supplement RBMPsby setting out national pollution reduction plans (PRPs) to meet WFD objectives forPSs and PHSs.

Each PRP outlines what is known about the production, uses and sources;summarises monitoring information on releases and presence in controlled waters;evaluates measures to reduce and where appropriate, to cease discharges,emissions and releases; and identifies an action plan which may be merely tomaintain the status quo if the EQS for a PS is complied with.

Where surface waters are considered to fail the EQS at the 95 percentile level or tobe at risk of failure or, in the case of PHS, where there is a WFD requirement tocease or phase out discharges, emissions and losses, action plans should be moresubstantial. However, the current PRPs largely identify the need for action ratherthan specific measures and, based on the available evidence, the likely targets forinvestigative work. Measures to reduce PS or PHS release beyond currentachievements will be the subject of site-specific investigations and policy decisions.

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Table B.13 WFD Prior ity and Prior ity Hazardous Substances

Priority Substance Priority Hazardous Substance

Alachlor Anthracene

AtrazineBrominated diphenylether

(pentabromodiphenylether)Benzene Cadmium and compounds

Chlorfenvinphos Chloroalkanes c10-13 (sccps)

Chlorpyrifos Endosulfan

1,2-dichloroethane Hexachlorobenzene

Dichloromethane Hexachlorobutadiene

Di(2-ethylhexyl) phthalate (dehp) Hexachlorocyclohexane

Diuron Mercury and its compounds

Fluoranthene Nonyl phenol

Isoproturon Pentachlorobenzene

Lead and compoundsPolyaromatic hydrocarbons (pahs sixberhoff substances excluding fluoranthene)

Naphthalene Tributyltin compounds

Nickel and compounds

Octylphenol

Pentachlorophenol

Simazine

Trichlorobenzenes (1,2,4-tcb)

Trichloromethane

Trifluralin

It should be noted that some PS and PHS are naturally occurring substances - egCd, Pb and Ni - or are present in diffuse releases from essentially uncontrolledsources such as old spoil heaps, old dump sites, the land, surface water run-off andprecipitation.

elv - eu practice

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