disposal and recycling routes for sewage sludge 14...

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Disposal and recycling routes for sewage sludgePart 4 – Economic report

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ISBN 92-894-1801-X

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Environment

Disposal and Recycling Routesfor Sewage Sludge

Economic sub-component report29 January 2002

European CommissionDG Environment � B/2

2

Table of Contents

1. EXECUTIVE SUMMARY AND MAIN CONCLUSIONS ......................................8

2. OBJECTIVES OF THE SUB-COMPONENT REPORT.........................................13

3. GENERAL METHODOLOGY ..................................................................................13

4. UNITARY COSTS AND BENEFITS OF SLUDGE ROUTES................................15

4.1 Unitary internal costs.....................................................................................................154.11 Methodology........................................................................................................154.12 Results .................................................................................................................174.13 Sensitivity analysis ..............................................................................................18

4.2 Unitary internal benefits ................................................................................................204.21 Methodology........................................................................................................204.22 Results .................................................................................................................214.23 Sensitivity analysis ..............................................................................................22

4.3 Summary of internal costs and benefits.........................................................................224.4 External costs and benefits: general overview ..............................................................23

4.41 Definition ............................................................................................................234.42 Objectives of this chapter....................................................................................234.43 Identification of impacts......................................................................................234.44 General valuation methods .................................................................................254.45 Feasibility of landfilling impacts valuation ........................................................274.46 Feasibility of incineration impacts evaluation....................................................324.47 Land use ..............................................................................................................364.48 Other recycling to land options...........................................................................414.49 Transport (all routes)..........................................................................................414.410 Other disamenities ..............................................................................................424.411 Conclusion ..........................................................................................................43

4.5 Quantifiable external costs and benefits........................................................................454.51 Methodology........................................................................................................454.52 Results .................................................................................................................474.53 Sensitivity analysis ..............................................................................................51

4.6 Global costs and benefits (internal and quantifiable external) ......................................53

5. SCOPE AND GENERAL ASSUMPTIONS...............................................................55

5.1 Sludge system and routes ..............................................................................................555.11 Part 1: the sewer system .....................................................................................555.12 Part 2: the waste water treatment plant (including dehydration).......................565.13 Part 3: treatment and disposal of sludge (including transportation)..................56

5.2 Time period ...................................................................................................................565.3 Stakeholders ..................................................................................................................575.4 Business-as-usual scenario ............................................................................................57

6. SCENARIOS.................................................................................................................61

6.1 Objectives......................................................................................................................616.2 Identification of the main changes to be introduced in the revised directive ................61

6.21 Scenarios definition.............................................................................................62

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6.22 Limit values for heavy metals in sludge ..............................................................636.23 Limit values for organic compounds in sludge ...................................................716.24 Pollution prevention policies and sludge quality ................................................776.25 Limit values for heavy metals in soil ...................................................................826.26 Obligation of treatment .......................................................................................896.27 Implementation of a quality assurance system....................................................926.28 Inclusion of industrial sludge..............................................................................946.29 Accession Countries ............................................................................................98

7. RESULTS......................................................................................................................100

7.1 Quantities (urban sludge in Member States) .................................................................1017.2 Unit costs.......................................................................................................................1027.3 Total costs and benefits (urban sludge in Member States) ............................................103

7.31 Scenario n°1 (efficient pollution prevention policy or PPP) ..............................1047.32 Scenario n°2 (No PPP) .......................................................................................105

7.4 Comparison of scenarios ...............................................................................................1067.41 Comparison of total cost .....................................................................................1067.42 Comparison of allocation of cost among stakeholders .......................................107

7.5 Repartition of total costs between Member States ........................................................1087.6 Weight of sludge management costs compared to overall water management costs ....1107.7 Sensitivity analysis ........................................................................................................1127.8 Other results (industrial sludge and Accession Countries)............................................114

7.81 Industrial sludge..................................................................................................1147.82 Accession Countries ............................................................................................115

7.9 Recommendations .........................................................................................................116

8. GLOSSARY ..................................................................................................................117

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List of tables

Table 1: Detail of the steps performed for the economic study 13

Table 2: Detail of the representative sample of sludge route analysed 14

Table 3: Groups of routes according to their internal costs 17

Table 4: Sensitivity factors and their impact on internal costs (%) 19

Table 5: Impacts of sludge disposal and recycling according to emission (Italic: not for use insilviculture and in land reclamation) � source: Scientific sub-component report 24

Table 6: Examples of methods to value external costs and benefits 25

Table 7: Impacts of sludge disposal and recycling (Italic: not for use in silviculture and in landreclamation) 27

Table 8: Valuation estimates of air emissions (� per kg emission) [COWI 2000]. 28

Table 9: Impacts of sludge disposal and recycling 43

Table 10: Unit emissions of sludge routes (unit g/tDM unless otherwise stated) 47

Table 11: Unitary external cost by route and pollutant (Euro/tDM) 48

Table 12: Sensitivity analyses of the main factors influencing external costs (%) 51

Table 13: Total costs and benefits (internal and external) of sludge routes (in � / t DM) 54

Table 14: Three proposed periods of time 56

Table 15: Detail of the main stakeholders supporting costs and benefits depending on their nature(prevention, remediation or external) 57

Table 16: Forecast of sludge production in the 15 Member States after the implementation of UrbanWaste Water Directive, initially forecasted to be in 2005 (source: EC, 1999 and ADEME, 1999for Italy and Sweden, ktDM/year) 59

Table 17: Percentage of sludge recycled in the European Member States as a percentage of total sludgeproduction since 1992. Source: European Commission, 1999. 60

Table 18: Key factors affecting implementation costs of the revised directive 61

Table 19: Definition of the scenarios 62

Table 20: Proposed limit values (short, medium and long term) compared with directive 86/278/EEC(mg/kgDM). 63

Table 21: Proposed limit values (short, medium and long term) expressed as a percentage of the lowerlimit values of directive 86/278/EEC (mg/kgDM). 63

Table 22: Number of national limits on heavy metals less strict than the proposed new limit values(short, medium and long term). Source: calculated from regulatory sub-component report 64

Table 23: Categories of countries according to available data on sludge quality. Source: adapted fromscientific sub-component report. 65

Table 24: Percentage of sludge failing to comply with the proposed new limit values (on the basis ofavailable annual average sludge quality, No PPP option) 68

Table 25: Quantities of sludge concerned by the proposed limit values (based on available informationon annual average sludge quality) 68

Table 26: Quantities of sludge failing to comply with the proposed new limit values to be implementedin the revised directive (on the basis of available annual average sludge quality, ktDM /year) 69

Table 27: Average internal and external unitary costs of switching from landspreading (route n°2) to

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incineration (route n°6) in the Member States (source: unitary costs and benefits) � Euro/tDM70

Table 28: Proposed limit values for organic compounds in sludge (mg/kg DM) compared to thenational limit values (source: adapted from the regulatory sub component report) 72

Table 29: available data on organic compounds concentration in sludge � mg/kg DM unless otherwisestated (Source: Scientific sub-component report) 73

Table 30: Percentage of sludge failing proposed limit values on heavy metals and organic compoundsin sludge 75

Table 31: Provisional potentially toxic element load from different sources entering urban wastewaterin EU countries (% of total input) Source: ICON 2000. For each metal, the major contributor ishighlighted in grey. 77

Table 32: Importance of sources of organic compounds (commercial, domestic and urban). Source:ICON 2001. High contributors are highlighted in grey. 78

Table 33: Category, sources and priority measures for reducing metal discharges into urbanwastewater. Source: adapted from ICON, 2001, Pollutant in urban waste water and sewagesludge 78

Table 34: Main costs, nature and stakeholder supporting the cost of pollution prevention 79

Table 35: Pollution prevention costs supported by industrials in the UK (source DETR-WRc, 2001) 80

Table 36: Comparison of proposed limit values on heavy metals in soil with directive 86/278/EEC(6<pH<7), (mg/kg DM). 82

Table 37: Categories of countries according to the current severity of national legislation on soilquality. Source: Regulatory sub-component report. 83

Table 38: Estimated proportion of soil failing to comply with the limit values on heavy metals (metalstaken individually). Source: JRC 2001 84

Table 39: Estimated proportion of soil failing to comply with the limit values on heavy metals (allmetals taken together) 84

Table 40: Estimated proportion of failing soil (%) 85

Table 41: Estimated proportion failing soil and related percentage of failing sludge 86

Table 42: Percentage of sludge failing proposed limit values in sludge and soil according to thevarious scenario 87

Table 43: Percentage of sludge production with �no treatment�. Source WRc-SEDE, 1994 90

Table 44: Quantities of sludge concerned by the obligation of treatment (ktDM/year) 91

Table 45: Quantities of sludge concerned by the quality insurance (ktDM/year) 93

Table 46: Sludge analysis costs and costs of analysis by type of sewage plant (Euro/tDM) 94

Table 47: Industrial waste recycled to land in Member States, by countries and by industrial sectors.Source: SEDE - WRc 2001, (ktDM/year) 96

Table 48: Percentage of industrial sludge failing proposed limit values on heavy metals - source:calculated from information in SEDE-WRc [2001] 96

Table 49: Assessment of quantities of industrial sludge failing limit values on heavy metals (tDM).Source: calculated from WRc � SEDE, 2001 97

Table 50: Comparison on mean values of organic compounds contents between European industrialsludge, European urban sludge and proposed limit values. Source: WRc � SEDE, 2001 97

Table 51: Sludge production and quantities of sludge recycled in ten Accession Countries (Source:Andersen Questionnaires and ETCIW, �Implementation of the urban waste water treatmentdirective in the ten Accession Countries�, scenario B or C, Final report, June 1999) 98

Table 52 : Quantities of sludge failing (and not failing) limit values in sludge and soil in Accession

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Countries (tDM/year) 99

Table 53: Quantities of sludge concerned by each key factor (ktDM/year) and percentage of the totalquantities of sludge spread on land 101

Table 54: Unit costs (Euro/tDM) and type of sludge concerned by the change in unit cost 102

Table 55: List of unit costs (Euro/tDM) and corresponding quantities of sludge (ktDM/year) concernedby the change in unit cost 103

Table 56: Detail of total costs of scenario n°1 (PPP), k�/year 104

Table 57: Detail of total costs of scenario n°2 (PPP), k�/year 105

Table 58: Comparison of total cost of scenario, k�/year 106

Table 59: Total costs (average of PPP and No PPP, medium scenario , kEuro/year) divided by totalquantities of sludge recycled (ktDM/year) 109

Table 60 : Comparison of maximum sludge management costs with overall water management cost(average EU 15, Source: OECD, The Price of Water; Trends in OECD Countries; 1999) 110

Table 61: Maximum costs of sludge management compared to overall water costs (Source: OECD,The Price of Water in 1999; Trends in OECD Countries, 1999) 111

Table 62: Sensitivity analyses of the main factors (based on the medium scenario cost evaluation) 112

Table 63: detail of total cost for industrial sludge in Member States (kEuro/year) 114

Table 64: Assessment of total costs due to new requirements in Accession Countries (k�/year) 115

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List of figures

Figure 1: Average internal costs of sludge disposal and recycling in Europe (Euro / tDM) 17

Figure 2: Range of variation of the internal costs of the selected routes in Member States (minimum,average and maximum, Euro / tDM) 18

Figure 3: Internal benefits of sludge recycled to land (Euro/tDM, average of EU 15) 21

Figure 4: Average internal costs and benefits for sludge recycling or disposal in Europe (average EU15, Euro/tDM) 22

Figure 5: Exposure of the population when disposing sludge to landfill 29

Figure 6: Exposure of the population when sludge is incinerated 33

Figure 7: Exposure of the population when sludge is used in agriculture 37

Figure 8: Quantifiable unitary external costs of sludge disposal or recycling (Euro/tDM, average EU15) 49

Figure 9: Quantifiable external costs and benefits of sludge disposal and recycling (Euro/tDM, averageEU 15) 50

Figure 10: Average net costs (internal and quantifiable external) of sludge disposal or recycling inEurope (average EU15, in � / t DM) 53

Figure 11: Detail of the three parts of the scope 55

Figure 12: Decrease of heavy metals content in sewage sludge in Upper Austria, 1980 � 2000[Aichberger, 2000] concerns 80 to 140 rural, urban and industrial plants, of which capacitiesvary between <1000 and 500 0000 inhabitants equivalent. 66

Figure 13: Decrease of heavy metals content in sewage sludge in Germany, 1977 � 1992/93 [ATV1996] 66

Figure 14: Evolution of the Cadmium content in the Nottingham, UK WWTP sludge since 1960.Source: Rowlands 1992 in Smith 1996. 67

Figure 15: Percentage of sludge failing new requirements on heavy metals in sludge in MS (short,medium and long term limits) 69

Figure 16: percentage of sludge failing limit values on heavy metals and organic compounds in sludgeaccording to the various limit values (short term, medium term, long term) 75

Figure 17: percentage of sludge failing limit values in sludge and soil according to the variousscenarios 87

Figure 18: allocation of costs among stakeholders (medium cost estimates, % of total, keuro/year) 107

Figure 19: Repartition of total costs among Member States, medium cost estimate (%) 108

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1. Executive summary and main conclusions

What are the economic impacts of new regulatory requirements for the disposal andrecycling of sewage sludge?

Evaluating and comparing different disposal and recycling options for sewagesludge

Landspreading routes rank best overall, landfilling and incineration routes worst

Landspreading of solid and landspreading of semi-solid sludge entail on average the lowest cost(110-160 �/ton of dry matter) from an overall economic point of view, i.e. accounting for bothinternal and external costs and benefits.

Landfilling, mono-incineration and co-incineration of sludge with other wastes entail the highestcosts (260-350 � /on of dry matter) from an overall economic point of view.

Landspreading of composted sludge, use of sludge in land reclamation, and use of sludge insilviculture record intermediate total costs (210-250 � /ton of dry matter).

Total costs are mainly composed of investments and operating costs of sludge treatment. However,the quantifiable environmental impacts (external costs) can make a difference as regards routeswhose internal costs are similar.

Whatever the sludge route investigated, total costs are mainly composed of investment and operatingcosts (internal costs and benefits) of infrastructure and of operations required for sludge treatment.The internal costs of landspreading of composted sludge, use of sludge in land reclamation and useof sludge for silviculture are among the highest.

Quantifiable environmental impacts, however, can be a factor in differentiating routes with similarinternal costs. For example, the environmental benefits associated with landspreading of compostedsludge make this route more attractive than the co-incineration of sludge with other waste, whereastheir net internal costs are similar.

Quantifiable environmental impacts (external costs and benefits) represent less than 15% of totalcosts. However, many environmental impacts such as impacts on soil biology, ecosystems and somelong-term effects on human health could not be quantified. Thus, the importance of environmentalcosts and benefits is in fact larger than estimated in this study.

The agronomic or farm value of sludge, assessed in terms of savings resulting from reduction infertiliser use, can represent between 10% and 30% of the cost of landspreading.

Farmers' interest in sludge can be increased due to treatments which enhance the fertiliser andenriching agent content of the treated sludge, e.g. tertiary treatment of nitrogen or phosphorus,liming, or mixing with a carbonated substance. However, such treatments lead to additional costs forsludge producers, which therefore means they may be of less general economic interest.

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Evaluating and comparing scenariosCosts of compliance with new requirements in terms of:

- More stringent limit values on heavy metals in sludge- New limit values on heavy metals in soils- New limit values on organic compounds in sludge- More stringent obligation of treatment- New requirements on sludge quality assurance system

range from 0.8 billion �/year in the short term to 1.0 billion �/year in the long term for the15 Member States of the European Union.The best estimates of costs necessary to meet new regulatory requirements of more stringent limitvalues on heavy metals in sludge, new limit values on heavy metals in soils and new limit values onorganic compounds in sludge, more stringent obligation of treatment and new requirements onsludge quality insurance systems amount to 0.8 billion �/year in the short term, 0.9 billion �/year inthe medium term (after 2015) and 1,0 billion �/year in the long term (after 2025) for the 15 MemberStates of the European Union.

The analysis shows that the �worst-case scenario�, where no sludge is able to meet new regulatoryrequirements without an efficient pollution prevention policy, leads to costs as high as 1.2 billion�/year for the 15 Member States of the European Union.

The share of the costs between Member States is approximately proportional to the relativequantities of sludge produced in each Member State.

Estimated percentages of sludge failing to comply with new requirements on heavy metalsand organic compounds are high if no pollution prevention policy is implemented.

According to our estimates, 67% of sludge in the short term, and 83% in the long term, fails tocomply with limit values on heavy metals or organic compounds in sludge or in soil, if no pollutionprevention policy is implemented.

If an efficient pollution prevention policy is implemented, then this percentage could drop down to25% (minimum due to proposed limit values on heavy metals in soil).

The integration of a Pollution Prevention Policy into the policy package leads to similaroverall costs.

- The integration of the necessary pollution prevention measures to minimise the diverting ofsludge from recycling, the so-called called the Pollution Prevention Policy scenario, leads to avery limited increase (less than 15%) in the overall costs of the policy.

- However, the evaluation of the costs of the measures required for the Pollution Prevention Policyscenario is difficult. As the costs used in the present study have been obtained from a single study(carried out in a United Kingdom context), cost estimates of such measures remain to beconfirmed and further analysed.

However, the Pollution Prevention Policy changes the allocation of the costs amongstakeholders: the Pollution Prevention Policy scenario shifts majority of the cost-burdenfrom the local authorities, farmers and citizens to the industry.

While the cost of an efficient pollution prevention policy is mostly borne by industries (around 60%for the medium term estimates), the local authorities (20%) and water companies (8%), the costwithout such a policy is borne mainly by local authorities (up to 60%, for the cost of switching fromlandspreading to incineration), farmers (up to 20%, for the loss of compounds of agricultural value)and citizens (up to 16%, for environmental and health impacts).

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This change in the cost-burden, however, should not mask the fact that costs allocated to localauthorities and water operators (costs of switching from landspreading to incineration and up to 70%of the costs of a quality insurance scheme) are ultimately borne by water consumers.

Sludge management costs remain low compared to the overall water management costsbut must be kept to a minimum

Sludge management costs remain relatively marginal when compared to the overall costs ofmanaging water and urban wastewater: internal costs of managing sewage sludge represent, onaverage for the 15 Member States, less than 6% of the total costs of water service (production,delivering and treatment).

However, consumer sensitivity to increases in water prices resulting from the significant increase inprices during the past decade may impose constraints on ensuring sludge treatment costs are kept toa minimum.

Compliance costs for industrial sludge should be lower than those for urban sludge

Whatever the scenario, costs of compliance with regulatory requirements that would also apply toindustrial sludge should be lower than those for urban sludge. This is mainly due to the lowerestimated production and better sludge quality.

Costs are estimated to range from 0,1 billion �/year in the short term to 0.2 billion �/year in the longterm.

Compliance costs in Accession Countries should be much lower than those borne byMember States.Costs of compliance with new regulatory requirements in ten European Union Accession Countries,i.e. Bulgaria, Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, Slovakia,Slovenia, should be significantly lower than those borne by the Member States. This is mainly due tothe lower quantities of sewage sludge currently produced and recycled in these countries, forecast tobe much lower than the quantities recycled in the Member States.

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Sensitivity, uncertainties and limitations of the study resultsThe estimation of costs associated with the various scenarios are very sensitive to forecasts ofquantities of sludge recycled, quantities of sludge not meeting new regulatory requirements andpollution prevention costs

The most sensitive factors for the analysis of scenarios are the forecasts of the quantities of sludgerecycled, the quantities of sludge not meeting new regulatory requirements and, for the PollutionPrevention Policy scenario, the costs of pollution prevention measures. Any variation in one of thesefactors leads to an almost proportional variation in the total costs of any scenario.

Sensitivity is relatively lower for other factors such as unit costs of switching from landspreading toincineration, quality assurance costs, sludge treatment obligations, nutrient concentration in sludge,and external cost coefficients.

Impacts of uncertainties on cost estimates for the scenarios are very highUncertainties regarding basic factors are very high overall. Thus, overall uncertainties for estimatesof costs associated with scenarios are high. Clearly, the results obtained in the present study are to beused very cautiously and remain indicative only.

Uncertainties that have the strongest impacts on the study results are the quantities of sludge notmeeting new regulatory requirements and pollution prevention management and costs. Otheruncertainties that were identified should have a more limited impact on the total costs estimated forthe different scenarios.

Evaluation of environmental and social costs is limited to airborne emissions and mayunderestimate the external costs and benefitsQuantifiable environmental and social costs were limited to airborne emissions. Thus, the impactson other natural environments (water and soil) have not been quantified.

As described in the scientific and technical report and in the social acceptance report, otherenvironmental effects or social issues may have significant impacts on the comparison of routes andscenarios. In particular, the lack of knowledge on how to economically quantify the impacts on soilbiology or the ecosystems, exposure to pollutants and their long-term effects on public health leadsto a limitation of the evaluation of external costs.

Moreover, the social costs and benefits such as unpleasant odours, the fears associated with theperception of environmental or health risks, the acceptance of sludge by the farming world or by thefood industry etc, are key factors to be considered in assessing the overall impact and costs ofdisposal and recycling options and scenario. These factors have however, not been quantified.

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Improving the economic analysis of sludge disposal and recycling: ideas for the wayforward

Improving the information base is necessary to increase the certainty of cost estimatesTo reduce uncertainties and improve the reliability of results, information is required on:

Sludge composition

A more precise evaluation of the percentage breakdown of sludge not meeting requirements wouldrequire a precise and updated percentage breakdown of pollutants (heavy metals and organiccompounds) in the quantities of sludge produced for all 15 Member States.

From general categories of sludge disposal and recycling routes to detailed databases with sludgequality, routes and treatments

More reliable results can be obtained if the database containing the details of sludge quality(percentage breakdown) were to include the type of treatment (conventional, advanced etc) and adetailed allocation of sludge to different disposal and recycling routes. The description of detailedcategories of disposal and recycling routes should be standardised among Member States.

Defining Pollution Prevention Policy measures and costTo obtain more reliable results on the impact of Pollution Prevention Policy measures on the costsfor scenarios, more analysis is required to better define the types of measures required for suchPolicy Prevention Policy in the various Member States. Also, better estimates of the costs associatedwith these measures are required.

Quantifying unknown external costs: human health, ecosystem degradation etc.To make a better evaluation of external costs, it would be necessary to improve knowledge on theeconomical quantification of impacts on soil biology, ecosystems, the exposure to pollutants andlong-term effects on health (see chapter on "gaps in knowledge" in the scientific and technicalreport).

Information databases should also be developed for industrial sludge and for AccessionCountries to the European UnionAt the present time, even less information is available on industrial sludge and the situation inAccession Countries than on urban sludge in Member States: for instance, basic information such assludge quantities and routes are not known. Therefore, more precise and reliable information shouldbe gathered on industrial sludge in Accession Countries in order to allow a comprehensive cost andbenefits analysis.

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2. Objectives of the sub-component report

The present report aims to:

- assess the economic impact of the main disposal and recycling routes for sewage sludge,

- perform an economic cost-benefit analysis of the revision of directive 86/278/EEC, in order toassess the economic implications of the changes that would be introduced.

3. General methodology

To meet the objectives stated above, the following steps have been performed:

# Step Chapter1 Evaluation of the internal unitary costs and benefits for a selected

sample of sludge routes4

2 Assessment of the environmental impacts and evaluation of theexternal unit costs of the selected sample

4

3 Definition of the scope (time frame, sludge routes,�) and generalassumptions

5

4 Identification of the main players and the type of costs and revenuesinvolved

6

5 Definition of the business-as-usual scenario 76 Selection of a limited number of scenarios 77 Comparison of the different scenarios and policy options 88 Sensitivity analysis 8

Table 1: Detail of the steps performed for the economic study

This study includes the treatment of sludge, after dehydration has been performed, and until its finaldisposal. Three main routes are currently performed for sludge disposal or recycling, which havebeen described in the Scientific sub-component report of this study: landfilling, landspreading andincineration. However, each one of those may present a great variety of options (such as the level ofdehydration, the kind of sludge treatment performed etc.), and we will therefore focus in this part ona selected sample of detailed and representative routes for identifying their costs.

The routes are representative of the actual and forecasted situation in Member States according tothe available literature (see scientific sub component report), the information collected in eachMember State from the ministry in charge of the issue and experts review.

All the routes and processes have been precisely described (dry matter, technologies�) in thescientific report. The assumptions made as representative of the existing situation in Member Stateshave been detailed in appendix 1.3.

For each representative route, we detailed in the table below:

- its importance (% of total production in average, with minimum and maximum percentage inMember States, source: Member States� Environment Ministries and EPA),

- the usual size of wastewater treatment plants that use this route.

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Route % of total sludgeproduction (2005forecasted, EC,

1999)

Detailed route1 Routenumber

Landfilling 51% Landfilling of solid sewage sludge # 1Landspreading of semi-solid sludge (nodigestion) # 2

Landspreading of solid sewage sludge(anaerobic digestion) # 3

Landspreading of composted sewage sludge # 4Landspreading of semi-solid sewage sludge(aerobic digested sludge) # 5

Use of sludge in land reclamation or green areas # 9

Recycling toland

23%

Use of sludge in silviculture # 10

Mono-incineration of sewage sludge # 6Co-incineration of sewage sludge # 7Incineration 21%Wet oxidation of sewage sludge # 8

Table 2: Detail of the representative sample of sludge route analysed

Note: Data concerning silviculture and wet oxidation routes are at the present time scarce and not as reliable as the one available for other routes. As in those casesquantities of sludge following those routes are not significant:

- Costs of silviculture were extrapolated from landspreading routes.

- Costs of wet oxidation have been only qualitatively compared to the ones of the incineration route.

1 More precision is available in appendix 1.3

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4. Unitary costs and benefits of sludge routes

The aim of this intermediate part is to assess both internal and external unitary costs (costs per tDMof sludge) and benefits of sludge disposal or recycling, for a representative sample of differentsludge routes.

These unitary costs and benefits will be used afterwards as a base for calculating the costs andbenefits of each scenario considered herein.

For each route taken into consideration, the following costs and benefits have been detailed:

- internal costs,

- internal benefits,

- external costs and benefits.

4.1 Unitary internal costs

4.11 MethodologyThe methodology applied for determining unitary costs details hereafter:

- the nature of costs included,

- the annualization of investment costs,

- the extrapolation of missing data.

It must be stressed that this methodology provides costs that are independent of:

- the type of management (public or private),

- the level of subsidies granted by public bodies.

The costs include:

- investment costs,

- operating costs.

Investment costs are assessed and annualised. The depreciation duration will be based on thephysical duration of the investment so that annuities include provisions for renewal. According towater operators, duration of investment can be defined as follows:

- 8 years for sensitive equipment (pumps, furnace�),

- 15 years for other investments (civil works and other equipment�).

The discount rate of 6% was used and sensibility analyses have been conducted with discount rate of4% and 2%.

Operating costs includes the following items:

- labour, energy and other consumables required for operating the various processes

- transportation, landspreading, and information requirements,

- disposal of residues (sludge or ashes�)

These costs will be evaluated using current European market prices.

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4.111 Methodology of data collection and processing

CollectionCosts are based when possible on European market prices and originate from different sources:statistics, documentary sources available in the literature (publications, proceedings of meetings�),and interviews made with European constructors / operators.

However, the quantity, precision and reliability of data collected were very heterogeneous betweenMember States. Therefore, we needed to perform an estimation of costs when data was incompleteor the assumptions not detailed.

ProcessingFollowing discussions with experts in wastewater treatment plant construction and operationindustry, we made the assumption that some items may have similar cost among Member States(mainly equipment, consumables,�), whereas other items costs may vary greatly among countries(civil work, work force, energy�).

The indices, assumptions and sources used to extrapolate costs from one country to another aredetailed in appendix (Group 2).

Average internal costs in Europe of the different sludge routes considered herein (expressed inEuro/tDM) are presented below.

Overall reliability

Considering the large variety of sludge routes, technologies, constructors, operators and the rapidchanges occurring, figures obtained should be viewed as �order of magnitude�, with an accuracy nobetter than 20-30%.

17

4.12 ResultsAccording to the assumptions retained and the methodology followed, average internal costs ofsludge disposal or recycling in the Member States are the following ones:

0

50

100

150

200

250

300

350

route

# 2 (la

ndsp

readin

g of s

emi-s

olid)

route

# 5 (la

ndsp

readin

g of s

emi-s

olid d

igeste

d)

route

# 3 (la

ndsp

readin

g of s

olid)

route

# 10 (

Silvicu

lture)

route

# 7 (c

o-inc

inerat

ion w

ith ot

her w

astes

)

route

#1 (la

ndfilli

ng)

route

#9 (la

nd re

claim

ation

)

route

# 4 (la

ndsp

readin

g of c

ompo

sted)

route

# 6 (M

ono-i

ncine

ration

)

Euro

/ tD

M

Landspreading (includingtransport and informationrequirement)

Incineration (includeddisposal of residus)

lanfilling of sludge(included transport to thelandfill)

composting (included co-product)

Extra deshydratation

investments (annuities)

Figure 1: Average internal costs of sludge disposal and recycling in Europe (Euro / tDM)

- It appears that the average costs of the different sludge routes considered herein vary from 160Euro/tDM to more than 300 Euro/tDM. Routes can be classified into three groups according to theiraverage costs:

- Range ofvalues (�/t

DM)

- Routes

- 160-210 - # 2, 5 (landspreading of semisolid sludge inagriculture,)

- 210- 300 - # 3 landspreading of solid sludge- #10 silviculture- #7 co-incineration with other wastes- #1 landfilling,- # 9 land reclamation

- 300-330 - # 4 landspreading of composted sludge- # 6 specific incineration

Table 3: Groups of routes according to their internal costsNote: Concerning the developing route of wet oxidation, not enough reliable data was available.

For each route, internal costs are detailed for each item (investments, operations, transport,landspreading, landfilling�) and for each Member State in appendix (group 2). The average,maximum and minimum costs in Member States are indicated in the figure below.

18

050

100150200250300350400450500

route

#2 (

lands

pead

ing of

semi-s

olid)

route

#5 (

lands

prea

ding

of se

mi-s

olid d

igeste

d)

route

#3 (

lands

pead

ing o

f soli

d)ro

ute #

10 (

sylvi

cultu

re)

route

#7

(co-

incine

ratio

n)ro

ute #

1 (lan

dfill)

rout

e #9

(land

recla

mation

)

route

#4

(land

spre

ading

of co

mposte

d)

rout

e #6

(mon

o-inc

inera

tion)

internal costs (min EU 15)

internal costs (max EU 15)

Euro

/tDM

internal costs (min EU 15)internal costs (average)internal costs (max EU 15)

Figure 2: Range of variation of the internal costs of the selected routes in Member States(minimum, average and maximum, Euro / tDM)

For all routes, with the sole exception of route #1 (landfilling), differences between the highest (orlowest) unit cost and the average are lower than 25% and the standard deviation is lower than 10%of the average. Those differences are mainly explained by the differences of the labour and civilwork costs in the Member States across the European Union.

For route #1 (landfilling of sludge), difference between the maximum cost and the average can reach80%. These differences are du to costs of landfilling that are highly variable among Member Statesor even, for each Member States, between sites.

4.13 Sensitivity analysisSensitivity analyses have been conducted for the following key factors:

- Type of process and technologies used,

- Storage duration,

- Specific equipment concerning the treatment of odours,

- Transport distances.

4.131 Process and technology used

These costs must be taken as an order of magnitude, especially for relatively fast evolving processessuch as composting. Therefore, costs should not be considered to have a better precision than 20-30%.

Besides some operators of municipal wastes incinerators may accept only sludge with a dry matterof 60% in order to have a similar behaviour than other wastes (co-incineration of dehydrated sludgewith 20% DM content may disturb the operation of the incinerator and in particular the flue gastreatment). In this case, sludge would need to be dried before being mixed with other wastes andcost would be higher and closer to that of mono-incineration.

19

4.132 Design specificity

Incinerators may be designed with an extra standby capacity, in order to be able to incinerate evenduring periods of heavy maintenance (usually one month per year). Costs are very sensitive to thisparameter - in the case of a 100% extra capacity, the cost of incineration would increase by almost50% (+140 Euro/tDM), due to the high investment costs.

4.133 Storage

Costs of recycling to land routes are very sensitive to the type and duration of storage that isnecessary when landspreading is directly not possible (especially in winter):

- if the storage (9 months) was not necessary for land use routes, costs of the landspreading routescould decrease significantly by more than 30% (-50 Euro/tDM),

- on the contrary, if storage has to be more sophisticated (cover, odour treatment ), costs of theseroutes could increase by 30% (50 Euro/tDM).

4.134 Local factors

(i) Odours

One of the most sensitive local acceptance issues is that of odour.

If the problem of odours is locally important (sensitive neighbourhood, sludge with high organicmatter content,�) deodorization treatment could increase the cost of landspreading routes whichinvolve transport and/or processing of unstabilised sludge.

As the incineration route is usually not affected by odour problems, the difference betweenincineration and landspreading route disposal costs would be smaller or even reversed.

(ii) Composting co-products

If the co-products necessary for composting sludge (green waste for instance - see scientific sub-component report) is available free of charge, then the cost of composting can be reduced by around10% (-34 Euro/tDM)

4.135 Transportation distancesInternal costs are not very sensitive to changes in transportation distance as most of the cost isrelated to loading/downloading of the sludge. Transportation costs represent less than 30% of totalcost.

Sensitivity factors are summarised in table below:

Sensitivity factors Routes concerned Impacts on internalcost of routes (%)

Process and technology used All routes ±30%

Design specificities Route # 6 (mono-incineration) +50%

Storage type and capacity Landspreading routes (#2, 3, 4, 5) ±30%

Local factors (co-products) Landspreading of composted (route # 4) -10%

Transportation distances All routes Not significant

Local factors (odours) All routes Not quantifiable

Table 4: Sensitivity factors and their impact on internal costs (%)

20

4.2 Unitary internal benefits

Internal benefits may come from:

- the savings of fertilisers (recycling routes),

- the recovery of energy during incineration or burning of biogas recovered in landfills or producedby digestion.

Market prices from operators of incinerator or landfill already take into account benefits from energyrecovery and thus are already accounted for in internal costs. Therefore, this section will onlyconcentrate on benefits that have not been taken into account yet and due to the savings of fertilisers.

As mentioned in the scientific sub-component, a sludge application of 10 tDM/ha onto soil isnecessary in order to observe detectable effects of organic matter on soil physical properties.Considering current regulatory limitations for sludge application onto soil in European MemberStates, this benefit do not occur, and cannot be considered as an internal benefit for the agriculturalproduction.

It may also be recalled that sludge contains water that is also applied onto land and can therefore beconsidered as an internal benefit, especially for Southern Member States. However, this benefitshould not be significant as:

- the quantities of water involved are limited: 5m3 / tDM for a typical dehydrated sludge(20%DM).

- the price of water paid by farmers for irrigation should be far less than the average price paid byindividual users2.

4.21 MethodologyInternal revenues were estimated by evaluating the savings of fertiliser, considering essentially thenutrients P, N, K, Mg, S, CaO (if lime treated) and the stable organic matter (if composted) contentof sludge.

The following steps have been performed:

- Estimation of the nutrients content of sludge (N, P, CaO), stable organic matter for different typesand uses of sludge,

- Evaluation of the market price of the nutrients and stable organic matter,

- Estimation of the savings in fertiliser, lime, and stable organic amendments (quantities and costs),

For N, P, K, S, CaO and Mg we used the methodology followed by WRc taken from a specific UKstudy3. The main assumptions are:

- benefit of K, S, Mg were evaluated to 18% of N+P benefits,

- availability of nutrients for plants was supposed to be 30% for N, 70% for P and 100% for CaO,

- a 10% yield increase was assumed when using sludge against supplying all N and P by usinginorganic fertiliser.4

2 Source: Syprea, (no data available.)3 Soulsby and al, 2000, Southern Water, UK, The Environmental and Agricultural Economics of Recovering Value from

Recylcing Treated Biosolids to Land.

21

Other assumptions are:

- lime treated sludge was added at a rate of 0,3 tCaO/tDM.

- the content of stable organic matter was assumed to be 40% for compost and 0% for raw sludge(stable organic matter is coming mainly from the co-product)5,

- for land reclamation, it was assumed that all the stable organic matter was valuable whereas thenutrient content was not of interest6,

- no specific information was found on fertiliser substitution for land use in silviculture. It wasassumed to be 50% of the ones for agriculture use.

4.22 ResultsAverage Results are illustrated in the figure below (note: benefits are expressed as negative figures).Figures and calculations are detailed in appendix (group 2).

-90

-80

-70

-60

-50

-40

-30

-20

-10

0Slud

ge (a

verag

e com

posit

ion)

Lime t

reated

slud

ge

Sludge

used

in si

lvicult

ure

Compo

st

Compo

st us

ed fo

r land

recla

imati

on

Euro

/tDM

Benefit from stable organicmatter (compost)

Benefit from lime at 0,3tCaO/tDM

Benefits from increase cropyield (=P)

Benefits from K, S, Mg (18%of N+P)

Benefit from P

Benefit from N

Figure 3: Internal benefits of sludge recycled to land (Euro/tDM, average of EU 15)

For sludge used in agriculture, internal benefits range from -54 Euro / tDM for a sludge with averagecomposition to -76 Euro / tDM for lime treated sludge and -78 Euro / tDM for composted sludge.

For sludge not used in agriculture, these benefits drops down to �27 Euro/tDM for silviculture and-24 Euro/tDM for compost used for land reclamation, as the nutrient content (N, P mainly) are not asuseful as in the case of agricultural use.

4 Source: WRc-Soulsby et al.. This yield increase was explained to come from soil conditioning properties of

sludge and/or to its micronutrient content5 Source: SYPREA6 Source: SYPREA

22

4.221 Differences between Member States

According to the methodology applied, internal benefits are directly proportional to theconcentration of nutrients in the sludge (N and P mainly). As nutrient concentrations can varysignificantly among Member States according to the available data (+/- 50% compared to theaverage), we identified high differences in these figures between Member States (+/- 50%).

4.23 Sensitivity analysisTertiary treatments may be performed in order to remove higher loads of nitrate and phosphoruscontained in wastewater. This may increase the N and P levels in sludge, and thus their agronomicvalue.

If we assume7 that the content of sludge from tertiary treatment is typically 4 %DM for N and 6%DM for P (compared with 3,6% and 4% average values for sludge), than the absolute agriculturalvalue can increase by 100% up to 100 Euro / tDM.

4.3 Summary of internal costs and benefits

Internal costs and benefits are summarised for each route in the figure below:

-100

-50

0

50

100

150

200

250

300

350

rout

e #2

(lan

dspe

ading

of s

emi-s

olid)

rout

e #5

(lan

dspr

eadin

g of

sem

i-soli

d dig

este

d)

rout

e #3

(lan

dspe

ading

of s

olid)

rout

e #1

0 (s

ylvicu

lture

)ro

ute

#7 (

co-in

ciner

ation

)ro

ute

#1 (l

andf

ill)ro

ute

#9 (

land

recla

mat

ion)

rout

e #4

(lan

dspr

eadin

g of

com

poste

d)

rout

e #6

(mon

o-inc

inera

tion)

Euro

/ tD

M Internal costs

Internal benefits(savings offertilizers)

Figure 4: Average internal costs and benefits for sludge recycling or disposal in Europe(average EU 15, Euro/tDM)

It appears that depending on the route, internal benefits range from -25 �/t DM to -78 �/t DM. Onthe contrary, internal costs are in average always higher than 150 �/t DM. Those figures show thatinternal benefits can represent between 10% to 30% of internal costs.

7 Source: OTV

23

4.4 External costs and benefits: general overview

The purpose of this chapter is to review and to monetise8 (where feasible) the externalitiesassociated with the recycling and disposal of sludge.

4.41 Definition

4.411 ExternalitiesExternalities can be defined9 as: "costs and benefits which arise when the social or economicactivities of one group of people have an impact on another, and when the first group fail to fullyaccount for their impact". They are not systematically valued as they concern non-marketable goodssuch as air quality, for which no market prices apply.

4.412 ImpactAn impact will be considered here as any change to the environment or to human health, whetheradverse or beneficial, wholly or partially due to the disposal or recycling of sludge.

We will distinguish direct impacts that can affect their targets directly following their emission intoone environmental media (air, water�) from indirect impacts, that can affect their target followingtransfers in the environment and the food chain (vegetables, animals�).

4.42 Objectives of this chapterThe current state of knowledge does not always enable us to evaluate or monetise impacts.Therefore, the purpose of this chapter is to assess the feasibility of impacts valuation for each routeand therefore to determine if related costs can be quantified, even partially, or not. If not, aim of thischapter will be to assess whether these costs are:

- low, considering the respect of regulations or codes of good practices,

- low, considering that current practices or the use of fertilisers may have a similar impact,

- highly variable depending on sociological criteria and local situations,

- impossible determine.

4.43 Identification of impactsIn this chapter, for each route taken into consideration, all possible impacts of sludge recycling ordisposal are summarised and described. This work is based on the Scientific and Technical Sub-component Report. It is then be possible to determine the necessary data for valuating those impacts,and assess the related cost or benefit when possible. Table below presents the impacts that arefurther analysed.

8 i.e. to assess the economic value in monetary terms.9 ExternE Project [1995]

24

Routes Emissions Impacts

Emissions of landfill gas to airHuman health (direct and indirect)Ecosystems degradationClimate change

Emissions of leachate to soilHuman healthSoil micro-organisms reductionDecrease in groundwater quality

Emissions of untreated or treatedleachate to water

Human health (direct and indirect)Ecosystems degradationDecrease in surface water quality

Landfilling

Noise, Odour, Visual intrusion Social acceptancePublic anxiety

Energy production Displaced emissions of pollutants toair

Emission of pollutants to air via smokestack

Human health (direct and indirect)Ecosystems degradationClimate changeBuildings degradation

Emissions of wastewater to surfacewater

Human healthDecrease in surface water quality

Emissions of leachate to soil(landfilling of ash)

Human healthSoil micro-organisms reductionDecrease in groundwater quality

Emission of leachate to water(landfilling of ash)

Human health (direct and indirect)Decrease in surface water quality

Incineration

Visual intrusion Social acceptancePublic anxiety

Pollutant volatilisation to air Human health (direct and indirect)Ecosystems degradation

Emissions of pollutants to surface water Decrease in surface water qualityHuman health (direct and indirect)

Emissions of pollutants to soil

Human health (Direct and Indirect)Decrease in soil valueDecrease in crop yieldLivestock health(Direct and Indirect)Decrease in groundwater qualityEcosystem degradationSoil micro-organisms reduction

Recycling toland

Odour Social acceptancePublic anxiety

Exhaust gas

Climate changeHuman healthEcosystems degradationBuildings degradation

Transport (allroutes)

Noise, Road traffic Social acceptance

Table 5: Impacts of sludge disposal and recycling according to emission (Italic: not for use insilviculture and in land reclamation) � source: Scientific sub-component report

25

4.44 General valuation methodsThe impact pathway approach defined within the ExternE project will be applied wherever possible.The different steps involved in this methodology are presented below:

Evaluation of the impact�

Evaluation of the pollutant dispersion�

Quantification of the exposure of the stock at risk�

Assessment of the impact using dose-response functions�

Conversion into monetary terms

According to the impact, several methods have been developed in Environmental Economics tovalue external costs. They either rely on relevant market prices or on preference revelationtechniques. Some examples are given in the table below.

Impact Detail of the impact Valuation Methods

Impact on MorbidityValue of year of life lostHospitalisation costsValue of Working Day lost

SPM10

MPM11

MPMHuman Health

Impact on Mortality Value of Statistical life SPM

Ecosystems Impact on the Existence ofecosystems (�Disamenity effects�)

Contingent Valuation MethodTransport Costs MethodHedonic Prices Method

SPMSPMSPM

Climate Global impacts on the ecosystems(Biodiversity, Human Health, �)

Discounting of each relevant costs SPM / MPM

Building materials Impact on the quality and thematerials

Replacement and maintenance costsValue of decrease of tourism

MPMSPM

Social utility Public anxiety, noise, odour, visualimpacts

Contingent Valuation MethodTransport Costs MethodHedonic Prices Method

SPMSPMSPM

Table 6: Examples of methods to value external costs and benefits

It appears from the previous table that the valuation of each cost or benefit is based on the valuationof each individual impact.

Following table summarises the possible cause of each impact, and the impacts that will be furtherconsidered for each route.

10 States preference methods11 Market price methods

26

Route Impact Emission

Human health (direct and indirect)

Emissions of landfill gas to airEmissions of leachate to soilEmissions of untreated or treated leachateto water

Ecosystems degradationEmissions of landfill gas to airEmissions of untreated or treated leachateto water

Climate change Emissions of landfill gas to air

Soil micro-organisms reduction Emissions of leachate to soil

Decrease in groundwater quality Emissions of leachate to soil

Decrease in surface water quality Emissions of untreated or treated leachateto water

Landfilling

Social acceptance, public anxiety Noise, odour, visual intrusion

Displaced emissions Energy recovery from incineration

Human health (direct and indirect)

Emission of pollutants to soilEmission to air via smoke stackEmission of leachate to water(landfilling of ash)Emissions of wastewater to surface water

Ecosystems degradation Emission to air via smoke stack

Soil micro-organisms reduction Emissions of leachate to soil(landfilling of ash)

Climate change Emission to air via smoke stackBuildings degradation Emission to air via smoke stack

Decrease in groundwater quality Emissions of leachate to soil(landfilling of ash)

Decrease in surface water qualityEmissions of wastewater to surface waterEmission of leachate to water(landfilling of ash)

Incineration

Social acceptance, public anxiety Noise, visual intrusion

Decrease in soil value Heavy metal application onto soil

Human health (direct and indirect)Pollutant volatilisation to airEmissions of pollutants to soilEmission of pollutants to water

Decrease in crop yield Emissions of pollutants to soilLivestock health (Direct and Indirect) Emissions of pollutants to soil

Ecosystems degradation Pollutant volatilisation to airEmissions of exhaust gas to airEmissions of pollutants to soil

Climate change Emission of exhaust gas to airSoil micro-organisms reduction Emissions of pollutants to soil

Buildings degradation Pollutant volatilisation to airEmissions of exhaust gas to air

Decrease in surface water quality Emissions of pollutants to surface water

Decrease in groundwater quality Emissions of pollutants to soil

Recycling toland

Social acceptance, public anxiety Noise, Odour

27

Route Impact EmissionClimate change Exhaust gasHuman health Exhaust gasEcosystems degradation Exhaust gasBuildings degradation Exhaust gas

Transport (allroutes)

Social acceptance Road traffic

Table 7: Impacts of sludge disposal and recycling (Italic: not for use in silviculture and in landreclamation)

4.45 Feasibility of landfilling impacts valuation

4.451 Climate change

Description of the impact

As mentioned above, landfill gas is mainly composed of carbon dioxide and methane, which areconsidered to be greenhouse gases. When landfill gas is not collected and recovered, it is emittedinto the atmosphere and contributes to climate change.

Valuation methodology

Assessment of the contribution of greenhouse gas emissions originating from disposal of sludge tolandfill implies performing the following steps:

- Assessment of greenhouse gases emissions due to sludge landfilling:

- amount of landfill gas produced per ton of sludge disposed of to landfill

- concentration of greenhouse gases in landfill gas- Assessment of the increase in the greenhouse effect due to sludge-borne landfill gas

- Assessment of the impact of climate change (impacts on water resources, human health,ecosystems etc. due to climate change)

- Costs assessment: as the impacts are very different, market prices as well as contingent valuationare used to value these costs.

COWI [2000]12 summarised the studies that performed a valuation estimate for air emission. Thesestudies are few in number, use different methods and do not valuate the same impacts. In some caseshealth and environmental effects are included in the valuation. As no other data is available, thosedata will however be used herein and are presented below.

12 A study on the economic evaluation of environmental externalities from landfill disposal and incineration of

waste, a study for the European Commission, DG Environment. 2000

28

Best estimate Low estimate High estimateEmission type � / kg emission

Estimatebased on

Relevantfor I/L *

CO2 0.004 0.003 0.005 Study 3 and 4 I & L

CH4 0.150 0.070 0.303 Study 3 and 4 LN2O 1.500 1.500 1.500 Study 3 LParticulates 24.000 12.501 32.575 Study 1,2 and 3 I & LSO2 9.000 4.079 13.196 Study 1,2 and 3 I & LNOx 16.000 3.290 21.455 Study 1,2 and 3 I & LVOC 1.500 0.757 2.960 Study 1 and 2 ICO 0.005 0.002 0.009 Study 1 and 3 I & LAs 600 162 1,168 Study 1 and 2 ICd 50 20 95 Study 1 and 2 ICr 500 133 958 Study 1 and 2 INi 10 3 20. Study 1 and 2 IDioxins 10,000,0000 2,339,717 17,630,080 Study 1 and 2 I & L

Table 8: Valuation estimates of air emissions (� per kg emission) [COWI 2000].Note *: The value is used for emissions from I: Incineration, L: Landfill disposal.

Studies:1) Rabl, A., J. V. Spadaro and P. D. McGavran (1998): Health Risks of Air Pollution from

Incinerators: A Perspective

2) EC (1996e) Economic Evaluation of the Draft Incineration Directive

3) EC (1996d) Cost-Benefit Analysis of the Different Municipal Solid Waste ManagementSystems: Objectives and Instruments for the Year 2000

4) CSERGE et al (1993) Externalities from Landfill and Incineration

The first three studies are all based on ExternE estimates of conventional pollutants. Studies 2 and 3include both health and environmental effects whereas study 1 only includes health effects.Therefore, the highest priority has been given to studies 2 and 3 in the benefits transfer.

Conclusion

Assessment of the contribution of sludge disposal to greenhouse gases emissions is possible usingthe COWI methodology and results. This methodology may also be used for other routes and otherimpacts linked with air pollution (health effects, building materials�)

4.452 Human health (direct and indirect)


Following sludge disposal to landfill, three main exposure routes may directly and indirectly affecthuman health. Firstly, human beings may be directly affected by landfill gas inhalation, or indirectlyfollowing ingestion of contaminated vegetal or animal products. Human health may also be affectedby leachate if this is emitted to surface or groundwater. Exposure routes are summarised in the figurebelow.

29

Pollutant Exposure route Exposure mode Worker Neighbour Consumer

Inhalation of volatilecompounds and dust � �

Air Consumption ofcontaminated foodstufffollowing air deposition

�

Water ingestion � �

Surface andGround Water

Consumption ofcontaminated foodstuff � �

Soil Dermal contact orinhalation �

Dermal contact �

PathogensHeavy metalsOrganic pollutants

SludgeManipulation Inhalation of sewage

sludge particles � �

Figure 5: Exposure of the population when disposing sludge to landfill


In order to assess the economic costs of the impacts of sludge disposal to landfill on human health,the following steps are to be performed:

- Assessment of the amount of sludge disposed of in �old� landfills where landfill gas and leachateare not collected

- Assessment of the amount of pollutants released into the environment:

- amount of leachate and landfill gas produced per ton of sludge landfilled- pollutant concentration in gas and leachate

- Determination of the pollutant concentration in the air or in the surface water, and of thepollutants transfer in the food chain

- Exposure of human beings to pollutants

- Assessment of health diseases according to dose-response functions:

- number of hospitalisation days- number of years of life lost

- Economic valuation (cost of the hospitalisation, of the restricted activity days, of the years oflife lost etc.)

30

Limits

Even if the assessment of health diseases and the economic valuation step could be achieved, nostudy is available in the literature enabling to assess the sludge-borne pollutant�s concentration in thesurface water and the soil, the resulting increased concentration in the food chain, and the humanexposure to those pollutants.

Conclusion

No further evaluation or quantification was conducted as:

- the COWI coefficients already used to value impacts on air already take into account impacts onhuman health,

- It may be reasonably assumed that these risks are limited when landfills comply with the actualEuropean directive13 and using the best available technologies with gas and leachate collectionand treatment (although many older landfills may not comply with this assumption yet.)

4.453 Ecosystems degradation


Some emissions following disposal of sludge to landfill may have an impact on ecosystems. Thoseconsidered herein are the emissions of landfill gas to air, or the emission of leachate to surface water.Impacts due to climate change following greenhouse gas emissions are described in a separatesection, as well as the impact on soil micro-organisms, which is assumed to be one of the mainconsequences of leachate emission to soil.

Landfill gas contains pollutants that may have an impact on plants and crops due to air depositionand/or absorption. It may further contaminate livestock and wild fauna after ingestion ofcontaminated plants. Emission of leachate to surface water may also have an impact on wild faunaand flora, especially on aquatic organisms. In addition to those direct impacts on species, emissionsmay induce changes in their biotope following eutrophication or acidification.

This impact arises mainly in old landfill without a bottom liner to retain and collect leachate andwithout gas collection and treatment. It may however be considered as negligible when consideringlandfills complying with regulatory requirements and using best available technologies.


When considering crops or livestock, economic evaluation of such an impact may be performed byusing market prices. When considering wild fauna and flora, the Hedonic prices method applies.However, the same requirements are necessary as in the case of the impact on human health:

- Assessment of the amount of sludge disposed of in �old� landfills where landfill gas and leachateare not collected

- Assessment of the amount of pollutants released into the environment:

- amount of leachate and landfill gas produced per ton of sludge landfilled

- pollutant concentration in gas and leachate- Determination of the pollutant concentration in the air or in the surface water, and of the

pollutants transferred to the fauna and flora

- Exposure of plants and animal

- Assessment of phytopathology (dieback or yield decrease) for plants and diseases for animalsaccording to dose-response functions

- Economic valuation

13 Council Directive 1999/31/EC of 26 April 1999 on the landfill of waste

31

Conclusion

Some external costs linked to air pollution may however be taken into account in COWI results.However, the economic evaluation of this impact may not be performed as steps of the methodology(1 to 4) can not be completed due to missing data.

4.454 Soil micro-organisms reduction


Disposal of sludge to landfill generates a leachate containing pollutants such as heavy metals ororganic compounds. As described in the scientific sub-component report, heavy metals are assumedto have long term impacts on soil micro-organisms� survival and diversity.


It may be assumed that this impact will mainly be observed on micro-organisms under the landfillsite, without impacting any agricultural production. Therefore only the Hedonic Price Methodshould be used in order to monetise the loss of biodiversity in landfill soil. As no data is available inorder to use this method, it may be assumed that the cost of biodiversity loss in soil is included in theremediation costs. However, a calculation would require information on the number of landfill inwhich sludge is disposed of and where leachate is not collected, to assess the volume of soil whichshould be remediated depending on the size of the landfill, and the costs of soil remediation in thedifferent Member States. Such data is not available, and this assessment is therefore not possible inthe scope of this study.

4.455 Decrease in groundwater and surface water quality

When considering landfill not corresponding to the �state of the art� design, leachate may be emittedto soil and by this mean reach the water table, or it may be emitted to surface water. This impactmay however be greatly reduced when considering landfills complying with regulatory requirementsand using best available technologies.

It appeared from the scientific and technical sub-component report that only minor quantities ofheavy metals and organic compounds are assumed to reach the groundwater following applicationonto soil. This conclusion could however be different when considering an �old� landfill site,depending on the soil type, the depth of the water table, and the pollution load in the leachate.

Consequences of a decrease in the groundwater and surface water quality induce the possible impacton human health and ecosystems which have been considered in the previous part of this chapter.Therefore, the only externality which is to be monetised here is the loss of existence value of theclean ground- or surface water. It is possible to use the Hedonic Price Method, or to assess theremediation costs, when remediation is achievable for groundwater. This necessitates an assessmentof the decrease in the water quality due to sludge borne pollutants following sludge disposal tolandfill, and a monetary evaluation of the damage caused. COWI [2000] estimated that it is currentlynot possible to cite any cost figures for emissions to soil and water. Insufficient scientific data isavailable to assess the impact caused by this emission. Therefore, at the present time, an economicevaluation is not possible.

32

4.456 Conclusion on landfill impacts

In addition, it can be reasonably assumed that these risks due to landfilling, especially for impactslinked with leachate, are limited when landfills comply with the actual European directive14 usingthe best available technologies with landfill collection and leachate collection and treatment.However, many older landfills may not yet meet this assumption.

4.46 Feasibility of incineration impacts evaluation

4.461 Energy recovery

Incineration of sludge and/or wastes generates excess heat which may be used as such or convertedinto electricity. Energy recovery could therefore be considered as an external benefit of sludgeincineration, considering the saving of non-renewable resources. However, considering the watercontent of sludge,

- either dewatered sludge is burnt, and in this case the energy generated during combustion willcontribute to remove the remaining water contained in sludge,

- or sludge may be dried before incineration, and in this case the energy recovered willcounterbalance the energy used to the purpose of drying.

In any case, the energy recovery of sludge incineration will be counterbalanced by the energy usedfor reducing the water content of sludge. This benefit may therefore be considered as negligible.



When sludge is incinerated, flue gas is produced, containing greenhouse gases, such as CO2 andNOx. Their relative contribution on climate change is described by global warming potentials givenin the scientific sub-component report. The NOx level in the gas emitted to the atmosphere may bereduced by using flue gas treatment methodologies. As previously observed, despite the high contentof nitrogen in sludge, NOx emissions are much lower than experienced from coal combustion[Werther and Ogada 1999].


The valuation methodology is the same as the one described previously in this chapter for disposalof sludge to landfill, taking into account the variation in composition of green house gases. Thismethodology will use the same COWI coefficients.

4.463 Human health (direct and indirect impacts)


Human health may be directly and indirectly affected by two main exposure routes following sludgeincineration. Firstly, human beings may be directly affected by flue gas inhalation, as it containscompounds such as heavy metals, dioxins, HCl, NOx, SO2, or particulate matter, or indirectlyfollowing ingestion of vegetal or animal contaminated products. Human health may also be affectedby waste water produced during the wet treatment of flue gas if this is emitted to surface orgroundwater. Exposure routes of human beings to sludge-borne pollutants are summarised below.


33


Inhalation of volatilecompounds and PM � �

AirConsumption of

contaminated foodstufffollowing air deposition

�

Surface andGroundwater

Consumption ofcontaminated water � �

Dermal contact withcontaminated soil � �

Soil

Consumption ofcontaminated foodstuff �

Dermal contact �

Pathogens

Heavy metals

Organic pollutants

SludgeManipulation

Inhalation of sewagesludge particles � �

Figure 6: Exposure of the population when sludge is incinerated

It may be assumed that those risks are reduced when sludge is incinerated in plants corresponding tothe state of the art design, that is where high level treatment of flue gas is performed, and wherewaste water is collected and treated.

It must be recalled here that, as documented by Ogada [1999]15 the emissions of dioxins and furansare lower from sludge incineration plants than from waste incineration and mercury emissions arebelow the limits. Despite its high content of nitrogen, NOx emissions are much lower thanexperienced from coal combustion, whereas N2O and CO are easily reduced at higher combustiontemperatures.


The assessment of the economic costs of the impacts of sludge incineration on human health may beperformed by using the same methodology as in the case of landfilling. In the case of incineration,the following data is needed:

- the amount of flue gas and waste water produced per ton of sludge incinerated,

- the pollutant concentration in waste water and gas.

15 Werther J.; Ogada T.; Sewage sludge combustion; Progress in Energy and Combustion science 25, 55-116,

1999

34

Conclusion

As stated in the previous chapter on climate change, the COWI coefficients partially take intoaccount health risks linked to air emissions. A more accurate assessment of the external costs relatedto health risks, taking all exposure routes into account, is however not feasible, as part of thenecessary data is missing. In particular, no average data is available to assess the transfer ofpollutants in the food chain and the exposure of the population without using very precise modelswhich have to be used for very specific cases.

It may however be reasonably assumed that risks are limited for recent incinerators complying withthe new European Incineration Directive 2000/76/EC and using the best available technologies withhighly efficient gas treatment.



Ecosystems may be impacted following sludge incineration by the emission of flue gas to air, or bythe emission of wastewater following the wet treatment of flue gas. Impacts due to climate changefollowing greenhouse gas emissions are described in a separate section.

Flue gas contains pollutants which may have an impact on plants and crops due to air depositionand/or absorption. These are, for instance, heavy metals, dioxins, NOx, SO2, HCl, and particulatematter. These may further contaminate livestock and wild fauna via ingestion of contaminatedplants. Emission of waste water to surface water may also have an impact on wild fauna and flora,especially on aquatic organisms. In addition to those directs impacts on species, emissions mayinduce changes in their biotope following eutrophication or acidification.


The same methodology as the one explained in the description of the impact on ecosystemsfollowing sludge disposal to landfill applies here. However, for the same reasons as for theassessment of impacts on human health (especially concerning step 3 and 4), no economic valuationis at the present time feasible.

Conclusion

As stated in the previous chapter on climate change, the COWI coefficients partially take intoaccount impacts linked to air emissions. However, it is not certain that all impacts related to thisimpact is included in these coefficients.

Again risks can be limited for recent incinerator complying with the new European directive andusing the best available technologies with highly efficient gas treatment.

4.465 Buildings degradation


Flue gas produced following sewage sludge incineration contains SO2 and NOx which are known tohave an impact on buildings due to acidic deposition on materials.

35


Gas emissions can be translated in term "loss of thickness" of building materials, and valued usingmaintenance and replacement costs. In addition, regarding building of aesthetic or cultural merit, theamenity value of historical stone should be added to calculate the total value of the impact of airpollution on building materials. The valuation methodology necessitates performing the followingsteps:

- Assessment of the amount of sludge-borne SO2 and NOx emissions

- Assessment of the gas concentrations in the air

- Assessment of the increase in the fragility of buildings (mass loss) and of the decrease in theesthetical/cultural value of the building

- Economic valuation: repair and maintenance costs, and contingent value

However, we will consider the amenity value of the material as non-significant in comparison toother impacts of air pollution. The costs of this specific impact will therefore not be included for thisevaluation.

Conclusion

As stated in the previous chapter on climate change, the COWI coefficients may take into accountpart impacts linked to air emissions. However, it is not certain that all information related to thisimpact is included in these coefficients.

Again risks can be limited for recent incinerator complying with the new European directive andusing the best available technologies with high standards of gas treatment.

4.466 Landfilling of ash

Ash remaining after sludge incineration may be used in road construction or disposed of to landfill.Therefore the impacts described before concerning landfilling of sludge also apply here. Theeconomic evaluation however necessitates performing an additional step, in which the amount of ashproduced by sludge incineration and its concentration in pollutants is assessed.

However, externalities related to the landfilling of incineration ash are assumed to be lower thanlandfilling of conventional waste, as sites suitable for ash disposal have to comply to tighterconstraints. Risks of emissions to soil and water are therefore reduced and related costs areconsidered here as low.

36

4.47 Land use

4.471 General considerationSludge is usually used for its agricultural value, i.e. as a substitute for fertilisers. This implies thateach impact have to be assessed relative to that which would occur when conventional mineralfertiliser is used.

4.472 Decrease in soil value

Sludge application onto agricultural land could lead to a loss of its value because of two mainreasons:

- sludge spreading increases the heavy metals concentration in soil, and could lead to levelsnearing current regulatory limit values imposed in the Member States (see Scientific sub-component report). As a consequence, products grown on this soil could potentially be refused bythe food industry.

- the perception of the landspreading practice in some countries could be used as a reason forreducing the price of land during a transaction. This is not related to a potential risk but to theperception the public may have of it. It is not always a rational reaction corresponding to thescientific evidence.

The agricultural land could therefore lose part of its value, which can be expressed as a proportion ofthe price of the land per hectare. According to the European Landowner Organisation (ELO), thisprice ranges in Europe from 2 500 to 25 000 �/ha. The magnitude of this potential loss of value ofthe agricultural land is however impossible to assess, as:

- it depends on the level of contamination of the land, and the time remaining before reaching alimit value for heavy metal in soil, which is highly variable from one soil to another. Anassessment performed in the scientific indicates that this time could range from 80 years to over600 according to the type of soil, the crop grown and the metal taken into consideration.

- it depends on the perception of the landspreading practice, which varies over time in eachMember State, even in each region, and is therefore not predictable.

It must be stressed that from the point of view of heavy metal addition to soil, fertilisers alsogenerate heavy metal increase in soil, without generating such suspicion.16

16 No reliable data is available concerning the comparison of quantities of heavy metals brought on soil by

different sources (sludge, fertiliser, manure�)

37

4.473 Human health (direct and indirect)


As described in the Scientific sub-component report, human health may be affected by sludge bornepollutants through several exposure routes. Those are summarised in the table below.


Dermal contact withsoil or volatile

compounds inhalation�

SoilConsumption of

contaminated foodstuff(animal and vegetal)

�

Water ingestion � �

Surface andgroundwater Consumption of

animal products �

Dermal contact withsludge or compost � �

PathogensHeavy metalsOrganic pollutants

Sludgemanipulation Inhalation sludge

particle or pollutants � �

Figure 7: Exposure of the population when sludge is used in agriculture

According to the conclusion of the scientific sub-component report, consumption of vegetal productsgrown on soil to which sludge has been applied could lead to human exposure to heavy metals. Themain exposure route to organic compounds would be the consumption of contaminated animalproducts. In those cases, exposure to sludge borne pollutants is not known. However, it must beobserved that the surface area to which sludge is applied corresponds at the European level to lessthan 7% of the utilised agricultural area17. It may therefore be assumed that the proportion offoodstuffs in human diet containing sludge borne pollutants is very low. An example of such anexposure calculation is given by Wild et al. [1994]18 for PCDD/Fs and reported in the Scientific sub-component report. This has also been documented by Nilsson [1996]19 for other organic compounds.

17 Source: ADEME � Arthur Andersen, 1999, Situation du recyclage agricole des boues d�épuration urbaines

en Europe. This report calculated the necessary surface area and the proportion of the used agricultural areafor the spreading of all sludge produced in the Member States, without taking into account its quality. Itcorresponds therefore to a theoretical worst case scenario. In all Member States, the proportion of the usedagricultural area would be below 10% with the exception of Germany. 20% would be necessary in this Statefor the spreading of all the sludge produced. However, at the present time, only 40 % of the sludge arerecycled to agriculture in Germany.

18 Wild et al.; The influence of sewage sludge applications to agricultural land on human exposure topolychlorinated PCDDs and PCDFs, Environmental pollution 83 357-369; 1994

19 Nilsson C., Swedish environmental protection agency; Organic pollutants in sewage sludge, contribution tohuman exposure to certain estrogen-perturbing compounds; 1996

38

Human beings may also be exposed to sludge borne pollutants if these are transferred to surface orgroundwater. However, according to the conclusions of the scientific sub-component report,pollutant transfers to groundwater are assumed to be low. Transfer to surface water heavily dependson local conditions and should be limited by the implementation of agricultural good practices.

It must be stressed that in the case of heavy metals provision to soil, they are also present in mineralfertilisers and animal manure. The assessment of their impact should therefore be performed in theperspective of a comparison of all products. Such a work cannot be performed accurately at thepresent time, as no reliable data is available on the level of heavy metals in fertilisers.

If the sludge application rate does not correspond to plant requirements, leaching of nitrate to thegroundwater may also occur, which may impact human health. The amount of nitrate released intowater tables due to sludge application is however impossible to assess, as it depends on each specificcase (crop, application rate, nitrate balance) and local conditions (soil types, depth of the water table,meteorological conditions). This risk may however be avoided if sludge spreading complies withagricultural good practices.

Human health could be affected after exposure to pathogens. This may be of concern whenconsidering other recycling-to-land options (such as sludge application in silviculture or on greenareas), but exposure of the public following landspreading onto agricultural land is reduced,considering that pathogens applied to soil mostly remain within the area where they have beenapplied. Moreover current regulatory provisions and recommendations of codes of practice areassumed to reduce the risk of exposure to pathogens.


As described previously for landfilling and incineration, the economic evaluation of this impactnecessitates first to assess the amounts of pollutants and pathogens released to the environmentfollowing sludge spreading, which can be done using statistical data provided by Member States.Then, it is necessary to assess the transfer of those pollutants in the environment media beforeassessing the exposure of human beings to those pollutants through the different routes describedabove. The following calculation would be to determine the importance of the health effect due tothose pollutants using exposure-response functions. The final step is the conversion of those healtheffects into costs, corresponding to the cost of human life, the number of hospitalisation days, thenumber of years of life loss, etc.

Conclusion

As stated above, the human exposure to sludge borne pollutants is impossible to assess withsufficient precision considering current state of the knowledge, as part of the necessary data ismissing. The economic evaluation of this impact is therefore impossible to perform. It may howeverbe assumed that this exposure is low and induces reduced costs, considering the low proportion ofthe utilised agricultural area on which sludge is applied and the few exposure assessments mentionedabove (see scientific sub-component report).

4.474 Decrease in crop yields

Scientific literature reports that excessive levels of metals in soil could lead to plant phytotoxicity,resulting in a yield decrease. However, current limitations concerning metal levels in sludge and insoil avoid the occurrence of levels high enough to provoke such phytotoxicity phenomena, and nodecrease in yield following sludge application has yet been described in the scientific literature,when complying with agricultural good practices. On the contrary, sludge is used for the nutrients itprovides to soil and crop, leading to a yield improvement. Moreover, metals are also present inmineral fertilisers usually applied on agricultural soils. This impact may therefore be considered asnegligible. It will not be further analysed in this study.

39

4.475 Livestock health


As described in the Scientific sub-component report, livestock may be exposed to pollutants andpathogens contained in sludge through two main exposure routes, which are the ingestion ofcontaminated soil, or the ingestion of contaminated feed. It must be stressed that livestock exposureto heavy metals may also originate from mineral fertiliser application to soil, as those also containssuch pollutants.

Valuation of the impact

The economic evaluation of such an impact may be performed by using the replacement cost of theanimals, corresponding to the market price of livestock.

Conclusion

However, livestock death which could have been related to the use of sludge in agriculture has neverbeen reported. It may also be assumed that current regulatory provisions and codes of practice havereduced the risk of exposure to pathogens. Therefore, the cost related to this impact will be assumedto be negligible, and will not be further analysed in this study.



Because sludge contains heavy metals, pollutants and pathogens, sludge landspreading may have animpact on ecosystems. Wild fauna and flora may be contaminated by heavy metals and organicpollutants released into the environment. Aquatic organisms could also be affected by thosepollutants if they are transferred to surface water following run-off. It must be recalled that mineralfertilisers also contain heavy metals, which may have the same impact on ecosystems as thosecontained in the sludge-borne ones. Pathogens may affect animals and plants as well, since sludgecontains plant pathogens. In addition to those directs impacts on species, emissions may inducechanges in their biotope following eutrophication or acidification.

Impacts due to climate change following greenhouse gas emissions are described in a separatesection, as well as the impact on soil micro-organisms, which is assumed to be one of the mainconsequences of metals release in soil.

It may be assumed that current regulatory provisions and codes of practice implemented in MemberStates reduce the risk of exposure to pathogens. In particular, plant pathogens have in general lowoptimum growth temperature, so that disinfection will be achieved at a lower temperature than formammalian pathogens. Sludge treatment will therefore reduce the application of plant pathogens tosoil. We will concentrate here on the impact of heavy metals and organic pollutants on ecosystems.


The valuation methodology is the same as that previously described for incineration or landfilling.

Conclusion

However, data needed to assess the distribution of sludge borne pollutants in the environment overtime is not available. Therefore the exposure assessment of wild fauna and flora cannot be achieved.For this reason, the economic evaluation of this impact may not be performed.

Furthermore, this impact should be similar to the impacts of fertiliser that sludge replaces,considering the content of heavy metals in sludge and fertiliser (see scientific sub-componentreport). Perception of externalities by the population is included in the section �social acceptance�.

40


The main impact sludge may have on climate change when spread onto land is caused by theemission of exhaust gas due to sludge transportation to the field and landspreading. This has alreadybeen described previously in this chapter.

Taking into account savings of fertiliser (from production to final use) may reduce (or on balanceinduce negative) net emissions of greenhouse gases.

4.478 Soil micro-organisms reduction


Soil micro-organisms may be affected by the addition of heavy metals on land following sludgelandspreading. As reported in the scientific sub-component report, heavy metals in particular areassumed to cause long term damages to soil micro-organisms� survival and diversity. This couldaffect the fertility of soil and have an impact on the value of the agricultural land on which sludgehas been applied. As mentioned previously, it must be recalled that mineral fertilisers also containheavy metals, which may have the same impact on ecosystems as those contained in sludge.However, compounds of agricultural value contained in sludge may compensate such an impact onsoil fertility.


If affecting soil fertility and therefore crop yields, the economic valuation of this impact is possibleby using the market price of the crop production which has been affected by microbial soilpopulation reduction. However, as mentioned before, microbial soil population and biodiversity maybe affected, and this should not only be considered from the point of view of soil fertility. Therefore,the Hedonic Price Method should be applied to valuate the loss of microbial biodiversity in soil.

Conclusion

This impact is a long-term impact whose importance is not known at the present time. Moreover,this impact has not been monetised: no price for microbial diversity loss is proposed in the literature,and remediation costs are inadequate for agricultural land. Therefore, the economic valuation of thisimpact is not possible for the purpose of this study.

Again, this impact should be similar to impacts of fertiliser that sludge replace, considering thecontent of heavy metals in sludge and fertiliser (see scientific sub-component report). Perception ofexternalities by the population is included in the section �social acceptance�.

4.479 Buildings degradation


Exhaust gas emitted to the air following sludge transportation contains compounds which are knownto have an impact on buildings due to acidic deposition on materials.


The valuation methodology described for incineration also applies here. As sludge transportation isassumed to contribute to a very low proportion of the total road traffic, those impacts will beconsidered as negligible. They will therefore not be further considered in this study.

41

4.4710 Decrease in water quality

Groundwater and surface water quality may be affected by sludge application on soil if sludge bornepollutants reach the water table through leaching or the surface water following runoff. Groundwatercould also be impacted by nitrate leaching. This could lead to further impacts on human health andecosystems which have been considered above. Therefore, only the value of the loss of water qualityis considered here.

It has been reported in the Scientific sub-component report that leaching of metals as well as oforganic pollutants to groundwater are assumed to be low. Concerning water quality, the importanceof the runoff phenomenon is not known, and is in any case highly dependent on local conditions butbeing limited if codes of good practices are respected.

4.48 Other recycling to land options

4.481 Use of sludge in forestry and silvicultureThe different impacts described concerning sludge spreading on agricultural soil also apply here.Some differences arise due to the fact that:

- Forestry or silviculture products contribute for a very low proportion to the human diet.Therefore costs of this impact should be even more limited than in the case of landspreading.

- Impacts on wild fauna and flora could be higher than in the case of landspreading, leading to anincrease in the cost of this externality.

- Impacts on surface water could also be more important because of nitrate leaching followingsludge application.

4.482 Use of sludge in land reclamation and green areas

The same remark applies here. It must however also be observed that risks may be higher due to theamounts usually applied onto land for land reclamation purpose. When using sludge in amenityareas, exposure of children could also be increased via soil contact or ingestion.

4.49 Transport (all routes)Whatever the disposal or recycling route, sludge has to be transported following its production at theWWTP. Transportation is the cause of several externalities on climate change, human health,ecosystems etc.

4.491 Climate changeExhaust gas is source of the emission of greenhouse gases contributing to climate change. Themethodology which has previously been described applies here. It is however necessary to assess anaverage transportation distance, the emission of exhaust gas per ton of sludge and kilometre, and theexhaust gas composition.

4.492 Human healthGases and particles contained in exhaust gas may also have an impact on human health. Themethodology for assessing impacts on human health described previously also applies here. As it isimpossible to assess the human exposure to exhaust gas originating from sewage sludgetransportation, the economic valuation of this externality is impossible to perform. It may beassumed that this could be low, considering the low contribution of sludge transportation to the totalroad traffic.

42

4.493 Ecosystems

Exhaust gases may have an impact on ecosystems following pollutants� deposition. The samemethodology as described above applies here. This externality can however not be assessed, as theexposure and impact on wild life due to exhaust gas originating from sludge transportation isimpossible to assess. For the same reason as for human health, it may be assumed that this impactcould be low.

4.410 Other disamenitiesIn some cases, externalities may not be linked to emission of pollutants but to the route in general asin the case of visual intrusion, noise, odour, and related road traffic. In addition, an importantexternality deals with the public anxiety: each route may be a matter of worry for the neighbouringinhabitants, or for the food consumers.

The externalities dealing with impact on the amenity (the �social utility�) can be valued using�States Preference� methods such as the �Contingent Valuation Method�, the �Transport CostsMethod� and the �Hedonic Prices Method�.

The purpose of these methods is to encourage the householders to reveal their preferences inmonetary terms, i.e. to express their willingness to pay (or to be paid) when changes in their amenityoccur. These methods are not general evaluation methodologies, and are usually based onquestionnaires. They shall be applied for each specific context in a defined area. More detail aboutstakeholders general preferences are detailed in the sub component social acceptance of sludgeroutes.

43

4.411 ConclusionFollowing table lists the impacts and related costs which have been described above, summarising ineach case in they may be quantified and, if not, if they are assumed to be low, highly variabledepending on local situations, or unknown.

Not quantified.Estimated asRoute Impact Quantified

Limited Unknown Highlyvariable (3)

Exhaust gas �TransportSocial acceptance �(3)Human health (direct and indirect) �(1) �(4)Ecosystems degradation �(2�)Climate change �

Soil micro-organisms reduction �(2�)Decrease in water quality �(2�)

Landfilling

Social acceptance, public anxiety �(3)Energy recovery �

Human health (direct and indirect) �(1) �(2)Ecosystems degradation �(2 )Climate change �

Buildings degradation �(1) �(2)Impacts from landfilling of ash �(1) �(2)Social acceptance, public anxiety �(3)

Incineration

Landfilling of ash � (2�)Fertiliser and organic matter supply �(1�)Decrease in soil value �(2��)Human health (direct and indirect) �(1) �(2��)Decrease in crop yield �(2��)Livestock health (direct and indirect) �(2��)Ecosystems degradation �

Climate change �

Soil micro-organisms reduction �

Buildings degradation �(1) �

Decrease in water quality �(2��)

Recycling toland

Social acceptance, public anxiety �(3)

Table 9: Impacts of sludge disposal and recycling

44

Notes:

Impacts quantified in the following parts of the report (external costs)(1) External costs are quantified partially through COWI coefficients for health effects due to airpollution.

(1�) Estimated with the replacement costs of fertilisers (see unitary internal benefits).

Impacts costs estimated as limited

(2) Could be considered as low if state-of-the-art technology is used for incineration (highly efficientflue gas treatment)

(2�) Could be assumed to be low, especially for impacts linked with leachate, when landfills complywith the actual European directive20 and using the best available technologies with landfill gascollection, leachate collection and treatment. However, many older landfills may not comply withthese assumptions yet.

(2��) Considered as low if regulation and code of good practices are respected. These impacts couldbe compared to those of the fertiliser that sludge replaces, considering that heavy are brought as wellby other sources (fertilisers, manure�). The impact and its related external cost seems thereforemainly due to the perception of the risk by the population rather than by the risk itself.

Impacts costs estimated as highly variable(3) Highly variable depending on several criteria that may differ for each stakeholder and on thelocal situation (see the social acceptance sub-component report).

Impacts costs unknown(4) Unknown for effects that would not be taken into account in COWI coefficients.


45

4.5 Quantifiable external costs and benefits

As stated in the previous chapter, only externalities linked with airborne emissions can be assessed,using coefficients from [COWI,2000].

4.51 Methodology

4.511 ScopeThe analysis of external cost covers the full life cycle of the disposal routes considered, from theinitial thickening process to the final disposal of solid residuals, including combustion ashes. Theanalysis also fully accounts for the environmental impact caused by the transport of sludge and theconsequent external cost associated with it.

4.512 Costs and benefitsWe will distinguish external benefits (emissions avoided) from the use-of-fertiliser from externalcosts due to direct process emissions, transport, energy consumption and production.

4.513 Methodology

External cost methodologyExternal cost of each routes were calculated through the following formula

Quantifiable (air borne emissions) external Costs and benefits (Euro/tDM)

=

Air Impacts (g /tDM) x Cost coefficient (Euro/g)

Where:

- Air emissions are impacts on air of pollutants (CO2, CH4, SOx, NOx�) evaluated with a LCA(Life Cycle Analyses) model (detailed below).

- Cost coefficients adopted to evaluate unitary costs (per gram of pollutant emitted) are based onbest available estimates, according to the review presented in COWI [2000] that summarises thestate-of-the-art design from several sources. Cost coefficients have been differentiated acrossMember States for all pollutants that have a local impact.

46

External benefits methodology

Benefits from the use of fertiliser are due to the avoidance of emissions of the fertiliser productionprocess. Assumptions made for the evaluation include:

- Nitrate fertilisers are assumed to be produced locally. Hence, indirect energy emissions havebeen computed from national energy production mixes.

- Fertilisers containing phosphorus and potassium are assumed to be produced in Morocco, asalmost 80% of European P or K fertilisers are imported and 65% (i.e. 85% of those 80%) areimported from Morocco and Tunisia together [OECD 1988, UN 1997].

- In the average scenario retained for the N-P content of sludge, the use of 1 tonne (DM) of sludgein agriculture as a fertiliser enables the substitution of 148 kg of N-fertiliser, 51 kg of P-fertiliserand 5 kg of K-fertiliser. Since the net external cost of all the routes that include a land applicationprocess is directly dependent on this value, a sensitivity analysis has been conducted to quantifythe relative impact of this parameter by considering the minimum, maximum and the averagevalues observed within Member States.

- For use in silviculture (respectively Land reclamation), the quantities of fertiliser (N, P, K)replaced are assumed to be 50% (respectively 0%) of that of agriculture.

The Life Cycle Analysis (LCA) model

Air impacts have been evaluated through an LCA model. This model has been adapted to the currentsituation in Europe from the model developed previously in France for the French Water Agenciesin 1999:

In particular, this model has been adapted to take into account of:

- new sludge routes (in particular land reclamation and silviculture),

- differences and specificity of European countries (energy mix, external cost coefficient percountry, sources of fertiliser �),

- new constraints (air and water discharge limit values) of European regulations, in particular thenew directive on incineration and on landfilling,

- updated information on processes (composting, incinerators, landfills�).

The full description of the initial model (sources, methodology, assumptions) is available in thepublication �Audit environnemental et économique des filières d�élimination des boues d�épurationurbaines�, Agences de l�Eau, 1999.

The full description of adaptations done to the initial model is available in appendix 3.2.

47

4.52 Results

4.521 Emissions (quantifiable air borne)For each route, the quantifiable air-borne emissions have been calculated with the model:

Pollutants[g/tDM]

TOTALROUTE 1

TOTALROUTE 2

TOTALROUTE 3

TOTALROUTE 4

TOTALROUTE 5

TOTALROUTE 6

TOTALROUTE 7

TOTALROUTE 9

TOTALROUTE 10

CO 57 49 90 151 90 331 610 151 51CO2 [kg/tDM] 791 18 632 618 1 398 1 397 1 435 618 19SO2 -10 104 103 373 106 1 005 841 373 105HC 382 177 370 567 371 20 1 394 567 188NOX 3 39 44 146 45 1 253 1 233 146 40PST 26 22 42 77 42 85 216 77 24H2S [kg/tDM] 10 0 10 0 0 0 0 0 0CH4 [kg/tDM] 23 0 0 0 0 0 0 0 0NH3 [kg/tDM] 0 0 0 42 101 0 0 42 0HCl 4 0 0 0 0 50 50 0 0HF 1 0 0 0 0 5 5 0 0Cd 0 0 0 0 0 0 0 0 0Cr 0 0 0 0 0 1 1 0 0Cu 0 0 0 0 0 1 1 0 0Hg 0 0 0 0 0 0 0 0 0Ni 0 0 0 0 0 1 1 0 0Pb 0 0 0 0 0 1 1 0 0Zn 0 0 0 0 0 1 1 0 0Dioxins 0 0 0 0 0 0 0 0 0

Table 10: Unit emissions of sludge routes (unit g/tDM unless otherwise stated)

48

Using the COWI best estimates unitary costs detailed in appendix 3.3, unitary external costs are the following ones:

Pollutants(Euro/tDM)

External costcoefficient(Euro/g)

route #2(landspreading of

semi-solid)

route #10silviculture)


solid)

route #1(landfilling)


semi-soliddigested)

#4(landspreading of

composted)

route #9 (landreclamation)

#6 (Incineration) #7

(co-incineration)

NOX 0,016 1 1 1 0 1 2 2 20 20SO2 0,009 1 1 1 1 1 3 3 9 8CO2 0,004 0 0 3 3 6 2 2 6 6PST 0,024 1 1 1 1 1 2 2 2 5Cr 0,5 0 0 0 0 0 0 0 0 0Dioxins 100000 0 0 0 0 0 0 0 0 0HC 0,0015 0 0 1 1 1 1 1 0 2Cd 0,05 0 0 0 0 0 0 0 0 0Ni 0,01 0 0 0 0 0 0 0 0 0CO 0,000005 0 0 0 0 0 0 0 0 0Zn 0 0 0 0 0 0 0 0 0 0Pb 0 0 0 0 0 0 0 0 0 0NH3 0 0 0 0 0 0 0 0 0 0Hg 0 0 0 0 0 0 0 0 0 0HF 0 0 0 0 0 0 0 0 0 0HCl 0 0 0 0 0 0 0 0 0 0H2S 0 0 0 0 0 0 0 0 0 0Cu 0 0 0 0 0 0 0 0 0 0CH4 0,15 0 0 0 3 0 0 0 0 0

Total N/A 2 3 6 8 9 11 11 37 41

Table 11: Unitary external cost by route and pollutant (Euro/tDM)

49

0

5

10

15

20

25

30

35

40

45

route

#2 (la

ndsp

eadin

g of s

emi-s

olid)

route

#10 s

ilvicu

lture)

route

#3 (la

ndsp

eadin

g of s

olid)

route

#1 (la

ndfilli

ng)

route

#5 (la

ndsp

readin

g of s

emi-s

olid d

igeste

d)

#4 (la

ndsp

readin

g of c

ompo

sted)

route

#9 (la

nd re

clamati

on)

#6 (In

cinera

tion)

#7 (c

o-inc

inerat

ion)

Euro

/ tD

M

CH4 [kg]

Cu

H2S [kg]

HCl

HF

Hg

NH3 [kg]

Pb

Zn

CO

Ni

Cd

HC

Dioxins

Cr

PST

CO2 (kg)

SO2

NOX

Figure 8: Quantifiable unitary external costs of sludge disposal or recycling (Euro/tDM, averageEU 15)

Landspreading routes present the lowest external costs

Almost all the landspreading route routes display the lowest external cost (between 2 and 12 Euro/tDM).Routes using compost have the highest external cost of land use routes.

Transport

The main external costs of landspreading routes are due to transport (up to about 50% of the total externalcost). Furthermore, the contribution of transport is even more significant for the routes that transport largeamount of moisture (small WWTP), that transport sludge mixed with other material (compost) or on longdistances (large WWTP).

Digestion

If coupled with gas recovery systems, the process of anaerobic digestion also produces favourableoutcomes in terms of external cost reduction both when compared to an aerobic digestion process and,also, when compared to a similar route where no digestion stage is performed.

In particular, a sensitivity analysis carried out specifically for route n° 3 suggests that including ananaerobic digestion stage decreases the overall external costs of the route by about 15% (for the averagescenarios retained). This benefit would increase proportionally with the increase in the rate of recovery ofthe biogas.

50

Incineration display the highest external costs

The routes that include an incineration process display the highest external costs (between 37 and 41Euro/tDM in the best estimate scenario.

The main contributors to external cost of this route are due to the NOx and SOx emitted during theincineration process.

The minor cost differences that occur between mono-incineration and incineration (less than 10%) areprimarily due to the different transportation distances involved in the two routes.

Landfill display intermediate external costs

The external cost of landfilling is between that of land use routes and that of incineration (roughly thesame external costs as composted sludge). In the scenario used for landfilling, which includes the partialrecovery of landfill gas, the route benefits originate from the fact that the recovery of landfill gasproduces a net environmental benefit that was accounted for. The external costs for this route rangebetween about 4 and 13 Euro per ton with 8 Euro/ton being the best estimate.

4.522 BenefitsThe identified benefit (saving of fertilisers)21 only applies to recycling to land routes. Compared toexternal costs, they are as follows:

-10

0

10

20

30

40

50

rout

e #2

(lan

dspe

ading

of s

emi-s

olid)

rout

e #1

0 (s

ylvicu

lture

)

rout

e #3

(lan

dspe

ading

of s

olid)

rout

e #

9 (l

and

recla

mat

ion)

rout

e #5

(lan

dspr

eadin

g of

sem

i-soli

d dig

es...

rout

e #4

(lan

dspr

eadin

g of

com

poste

d)ro

ute

# 1

(land

filling

)ro

ute

#6 (m

ono-

incine

ratio

n)ro

ute

#7 (

co-in

ciner

ation

)

Euro

/ tD

M

Quantifiable externalcosts (EU 15 average)

quantifiable externalbenefits (use offertilizer)

Figure 9: Quantifiable external costs and benefits of sludge disposal and recycling (Euro/tDM,average EU 15)

For the average content of nutrient used for sludge, the impact of fertiliser substitution typically rangesbetween 20% and 100% of the total external cost of each route (with the sole exception of route #2landspreading of semi-solid sewage sludge for which it reaches about 2 times its total cost.).

21 As for internal benefits, energy recovery has already been taken into account into external costs

51

Furthermore, a sensitivity analysis applied to the nutrient content in sludge (that varies by +/- 50%between Member States) shows that the net benefit of this practice varies proportionally with the nutrientcontent of the sludge (+/- 50%)

Within this group, the routes that use landspreading in agriculture are more advantageous than those inwhich the sludge is used for land reclamation or silviculture because of their more favourable fertilisersubstitution rates.

4.523 Differences between Member StatesDifferences in external costs across countries are relatively small. This is mainly due to the fact that mostof the emissions associated with the disposal routes considered have global environmental effects forwhich the cost coefficients used to quantify externalities are identical across different Member States(C02, CH4�) Therefore, most of the resulting differences across countries are primarily the consequencesof different amounts of displaced emissions and � ultimately � of the different energy mix of eachMember State.

The contribution of displaced emissions to the reduction of total external costs is proportionally larger inthose countries that have an energy mix mainly based on carbon-intensive technologies. Conversely, thebenefits associated with the recovery of landfill gas are less significant or tend to disappear in thosecountries whose energy mix is mainly based on nuclear or renewable energies (ex. France and Sweden).

4.53 Sensitivity analysisResults of the sensitivity analysis performed are summarised in the table below:

Type ofcosts Sensitivity factors

Routesconcerned Uncertainties on

factors

Relative impacton external

costExternalnet costs

External Costs coefficients All routes +/- 60% +/- 50%

Landfilltechnology

Recovery of biogas Route #1 (landfilling) +/- 100% +/- 50%

(+/- 4 Euro /tDM)

Table 12: Sensitivity analyses of the main factors influencing external costs (%)

4.531 Cost Coefficients

In order to account for the uncertainty associated with the underlying valuation methodology and theaccuracy of the available data, the quantification of external costs has been repeated for three levels ofcost coefficients (medium, best and maximum) in accordance with other definitive studies on theevaluation of environmental externalities [COWI 2000]. These different coefficients reflect theuncertainties still existing in the scientific literature with respect to the economic evaluation ofenvironmental damages. As a consequence, three different values for the total external cost have beenreported for each route, according to the three cost coefficients used.

Results are sensitive to the assumptions made regarding costs coefficients (best estimates, minimal ormaximum) When cost coefficients vary, on average, by around 60% (from +/- 25% for CO2 to more than100% for CH4), external costs vary around the best estimates by around 50% (from 30% to 65%depending on the route).

52

4.532 Landfill technologyIn a less optimistic scenario, where the landfill is not equipped with gas recovery and leachatecontainment systems, the total external cost of the route would be larger (mainly as a result of thecontribution of the gas produced by the landfill and not recovered).

4.533 LimitationsThe following conclusions only apply to the case of state-of the-art incinerators and landfills, bothequipped with state-of-the art systems for energy recovery, air and water emission control. This may beapplicable to recent and modern installations but is probably not yet representative of the actual situationin all European countries, especially for old landfills.

As stated previously, due to lack of knowledge, the quantification of external cost has been restricted toairborne emissions. As a consequence, the results obtained tend to underestimate the external costs ofthose disposal routes for which the largest impact is caused by pollutants that are released to differentenvironmental media (for instance direct emissions of heavy metals to soil due to landspreading or due tospillovers of landfill leachate).

However the conclusion should remain the same if we consider that emissions to water and soil are lowfor a state of the art installation (incineration, landfill) and comparable to fertiliser for land use routes.

53

4.6 Global costs and benefits (internal and quantifiable external)

Net internal and external costs have been detailed for each route in the figure below:

0

50

100

150

200

250

300

350

400

rout

e #2

(lan

dspe

ading

of s

emi-s

olid)

rout

e #5

(lan

dspr

eadin

g of

sem

i-soli

...

rout

e #3

(lan

dspe

ading

of s

olid)

rout

e #1

0 (s

ylvicu

lture

)

rout

e #4

(lan

dspr

eadin

g of

com

poste

d)ro

ute

# 9

(lan

d re

clam

ation

)ro

ute

# 1

(land

filling

)ro

ute

#7 (

co-in

ciner

ation

)ro

ute

#6 (m

ono-

incine

ratio

n)

Euro

/tDM

Net externalcosts (costs-benefits)

Net internal cost

Figure 10: Average net costs (internal and quantifiable external) of sludge disposal or recycling inEurope (average EU15, in � / t DM)

54

All the figures corresponding to the data are summarised in table below:

Costs (Euro / tDM)ro

ute

#2(la

ndsp

read

ing

ofse

mi-s

olid

)ro

ute

#5(la

ndsp

read

ing

ofse

mi-s

olid

dige

sted

)ro

ute

#3(la

ndsp

read

ing

ofso

lid)

rout

e #1

0

(silv

icul

ture

)

rout

e #4

(lan

dspr

eadi

ng o

fco

mpo

sted

)

rout

e #

9 (l

and

recl

amat

ion)

rout

e #

1(la

ndfil

ling)

rout

e #7

(co-

inci

nera

tion)

rout

e #6

(mon

o-in

cine

ratio

n)

Internal costs 164 164 211 237 310 260 255 247 318Internal benefits (savingsof fertilisers) -54 -54 -54 -27 -78 -24 0 0 0

Net internal cost 110 110 157 210 232 236 255 247 318Quantifiable externalcosts (EU 15 average) 2 9 6 3 11 11 8 41 37

quantifiable externalbenefits (use of fertiliser) -5 -5 -6 -3 -5 0 0 0 0

Net external costs(costs-benefits) -3 4 0 0 6 11 8 41 37

Net internal andexternal costs 107 114 157 210 238 247 263 288 355

Table 13: Total costs and benefits (internal and external) of sludge routes (in � / t DM)

The analysis of this table leads to the following conclusions:

Landspreading of semi-solid and landspreading of solid sludge entail on average the lowest total cost(107-160 �/ton of dry matter).

Landfilling, mono-incineration and co-incineration of sludge with other wastes entail the highest costs(260-360 � /on of dry matter).

Landspreading of composted sludge, use of sludge in land reclamation and use of sludge in silviculturerecord intermediate total costs (210-250 � /ton of dry matter).

Whatever the sludge route investigated, total costs are mainly composed of investment and operatingcosts (internal costs and benefits).

Quantifiable environmental impacts, however, can be a factor in differentiating routes with similarinternal costs. For example, the environmental benefits associated with landspreading of compostedsludge make this route more attractive than the co-incineration of sludge with other waste.

Quantifiable environmental impacts (external costs and benefits) represent less than 15% of total costs.However, many environmental impacts such as impacts on soil biology, ecosystems and some long-termeffects on human health could not be quantified. Thus, the importance of environmental costs and benefitsis in fact larger than estimated in the present study.

55

5. Scope and general assumptionsThis part defines the scope and general assumptions that will be valid for all scenarios, including thebusiness-as-usual scenario.

General assumptions relate to:

- The sludge �system� and the sludge �routes�,

- The quantities of sludge and time period considered.

Other assumptions that may vary between scenarios will be detailed in each of the scenario definitions.

5.1 Sludge system and routes

The scope of the study includes all steps from the discharge of pollutants into the wastewater collectionsystem up to the final use22. For the purpose of the economic analysis, three parts may be distinguished:

Part 1 Part 2 Part 3

Final disposal ortreatment(includingtransportation)

Waste watertreatmentplant

( includingdehydration )

Sewer system

Figure 11: Detail of the three parts of the scope

5.11 Part 1: the sewer systemAs regulations concerning sludge should not affect the main costs of part I (pipes, pumps�), we willfocus only on the costs of pollution prevention policies.

The two options that will be considered are the following:

- no effort is made, and the sludge quality remains the same as the current sludge quality (scenario n° 2),

- important steps are taken to implement a pollution prevention policy which maintain the maximumquantities of sludge to be used on land (scenario n° 1).

22 up to the final accumulation of the substances and elements in the different media (air, soil, water) and living

organisms (plants, animals, human beings). Source: Terms of Reference

56

5.12 Part 2: the waste water treatment plant (including dehydration)The choices of wastewater treatment and sludge treatment are, in most cases, independent: almost allsludge treatment routes are possible, with similar additional costs, with all types of WWTP (primary,secondary or tertiary). In other terms, the choice of a WWTP treatment (primary, secondary, and tertiary)does not generally influence the choice of sludge route (landfilling, landspreading or incineration).

Furthermore, we will consider that a standard wastewater treatment plan treats the sludge with a typicaldehydration process producing sludge with a 20% of DM.

If a route requires a different dehydration process with a higher (respectively lower) dry matter content,we will take into account additional costs (respectively savings) of dehydration.

5.13 Part 3: treatment and disposal of sludge (including transportation)This part corresponds to the scope previously studied in detail on unitary cost and benefits, i.e. from thedehydration process until final disposal of the sludge.

5.2 Time period

As no recommendation23 concerning the time period to consider is specified in the �Guidelines onCosting Environmental Policies� published by the European Commission, we used a time period longenough to take into account:

- the increase in sludge production until the full implementation of the Urban Waste Water Directive of1991 (forecasted by 2005),

- short, medium and long term targets that could be introduced in the revised directive24,

Therefore, we propose to take into account three periods of time, detailed in table below:

Period Short term Medium term Long term

Forecasted date <2015 2015-2025 >2025

Table 14: Three proposed periods of time

If no delay occurs, quantities and costs evaluated hereafter will correspond to the date initially forecasted(i.e. Y=2005); if there is a N25 years delay in a country, estimates (quantities and costs) will correspondthe year Y=2005+N.

23 We have identified only recommendations concerning the speed of implementation24 as defined in the working document on sludge-3rd draft (medium and long term target being forecasted about

2015 and 2025 respectively)25 Note: Delays could not be quantified by the EC, despite our specific question.

57

5.3 Stakeholders

Stakeholders supporting the costs are different according to the type of the cost. For each type of cost orbenefits (prevention, remediation, external), the main stakeholders supporting the costs are summarised inthe following table:

Nature of Cost or benefit Type of cost Stakeholder

Reduction of pollutants loads in thesewer Industries

Pollution prevention costsPolicy implementation and control Local authorities

Investments and operational cost(internal cost)

Local authorities andindustries

Loss of use of sludge as a fertiliser(internal benefit) Farmer

Costs of switching fromlandspreading to incineration(sludge failing)

External net cost Citizens

Quality assurance (sludge notfailing) Internal cost Water and sludge management

operators

Obligation of treatment (sludge notfailing) Internal cost Water and sludge management

operators

Table 15: Detail of the main stakeholders supporting costs and benefits depending on their nature(prevention, remediation or external)

5.4 Business-as-usual scenario

5.411 General DefinitionThe business-as-usual scenario is defined as the scenario that �would emerge if the policy were notimplemented�26. It is therefore the scenario that would emerge if the directive 86/278/EEC was notrevised and was still in force during the considered period of time.

5.412 Regulatory situationAs almost half of the Member States adopted a national regulation that is significantly more stringent thanthe actual directive 86/278/EEC (see the regulatory sub-component report), we will consider the business-as-usual scenario as the current regulatory situation in each Member State, in accordance with eachnational legislative regime.

Even if it some Member State legislation (in particular MS whose national legislation is currently as strictas the directive 86/278/EEC) may change their national legislation in the future, even if the directive86/278/EEC is not revised, no other assumption may safely be done concerning a possible evolution ofnational legislation in the coming years.

26 Guidelines on Costing Environmental Policies, DG Environment, Draft February 2000, §4.2 Establishing a

baseline or �business as usual scenario�

58

5.413 Quantities of sludge concerned

5.414 Sludge production key factors

Sludge production is mainly linked to the following factors:

• human factors: the size of the population,

• technical factors:

- proportion of population having access to the public sewer system,- efficiency of the sewer system (no treatment, primary, secondary or tertiary treatment),

• other factors: size and number of industries connected to sewerage system.

5.415 Sludge production evolutionThe implementation of the UWW Directive 91/271/EEC lead and will lead to a very important increase ofWWT capacities and hence of sludge production.

During the same period the sludge production in the EC was forecasted to increase more than ten timesfaster than the rate of population increase (almost by 70%27 between 1992 and 2005, whereas thepopulation increased by 6 %28 within the same period). Considering the uncertainties linked with sludgeproduction (delays and quantities�) we will consider the human factor as negligible.

In addition, we will consider the contribution of industries as steady, as two phenomena should haveopposite effects. On the one hand, the size of industries is growing due to economical growth, on otherhand, quantities discharged by industry should decrease due to process improvement and pollutionprevention, and the rate of industries connected to the sewer should decrease, due to increasing industrialonsite wastewater treatments.

Therefore, we can consider that sludge production will be steady once the UWW directive will be fullyimplemented

Sludge production considered for each Member State will be as follow:

27 Source: European Commission, 1999, report on implementation of council directive 91/271/EEC28 source: Eurostat, 2001

59

Country Total production(ktDM/y)

Austria 195Belgium 159Denmark 200Finland 160France 1.172Germany 2.787Greece 99Ireland 113Italy 959Luxembourg 14Netherlands 401Portugal 359Spain 1.088Sweden 323UK 1.583EU15 9.611

Note: For Sweden and Italy, the increase between 1998 and 2005 is assumed to be the average increase of the 13other Member States

Table 16: Forecast of sludge production in the 15 Member States after the implementation ofUrban Waste Water Directive, initially forecasted to be in 2005 (source: EC, 1999 and ADEME,

1999 for Italy and Sweden, ktDM/year)

5.416 Proportion of sludge concernedAs the directive only concerns �the protection of the environment, and in particular of the soil, whensewage sludge is used in agriculture� the revision of the directive should only affect the quantities ofsludge that are recycled on land. Therefore, we will focus on quantities of sludge of the �re-use� category,which represent around half of the total production.

Besides, it appears from the data on sludge disposal and recycling in the Member States that in most casesthe proportion of sludge recycled has been constant since 1992 (see table hereafter). We have thereforemade the assumption that this would remain true in the business as usual scenario, although the analysisof the social acceptance of sludge showed increasing reluctance in some countries.

60

Country 1992 1995 1998 2000 (e) 2005 (e)Austria 33% 33% 35% 35% 35%Belgium 29% 28% 29% 31% 30%Denmark 63% 65% 63% 63% 63%Finland 58% 54% 57% 60% 72%France 63% 64% 65% 65% 65%Germany 46% 46% 48% 49% 50%Greece 2% 2% 5% 6% 7%Ireland 11% 18% 58% 65% 74%Italy NA NA NA NA NALuxembourg 56% 70% 69% 69% 64%Netherlands 41% 26% 26% 27% 27%Portugal 30% 30% 30% 30% 30%Spain 52% 52% 52% 54% 54%Sweden NA NA NA NA NAUK 47% 56% 56% 69% 71%

(e) : estimations.Table 17: Percentage of sludge recycled in the European Member States as a percentage of total

sludge production since 1992. Source: European Commission, 1999.

Therefore, sludge production and recycled quantities that will be considered are the ones forecasted afterthe implementation of the urban waste water directive and are detailed in table below:

Country Recycled

(ktDM/y)

Totalproduction(ktDM/y)

Recycled

(%)Austria 68 195 35%Belgium 47 159 30%Denmark 125 200 63%Finland 115 160 72%France 765 1.172 65%Germany 1.391 2.787 50%Greece 7 99 7%Ireland 84 113 74%Italy 189 959 20%Luxembourg 9 14 64%Netherlands 110 401 27%Portugal 108 359 30%Spain 589 1.088 54%Sweden 167 323 52%UK 1.118 1.583 71%EU15 4.893 9.611 51%

Table 17: Forecasted quantities of sludge recycled in the 15 Member States after theimplementation of Urban Waste Water Directive, (source: EC, 1999 and ADEME, 1999 for Italy

and Sweden, ktDM/year)

61

6. Scenarios6.1 Objectives

The objective of this section is to assess both internal and external costs and benefits of the revision ofdirective 86/278 when introducing the requirements that would be set in the revised directive29 byperforming the following steps:

- Definition of the business-as-usual scenario (see previous chapter),

- Identification of the main changes that would be introduced in the revised directive compared to thebusiness-as-usual scenario,

- Definition of scenarios and key factors,

- Calculation of the quantities concerned by each key factor and the unit costs associated

- Calculation of the total costs and benefits for each scenario,

- Comparison of scenarios,

- Sensitivity analysis.

6.2 Identification of the main changes to be introduced in the revised directive

In order to define the scenarios that will be evaluated, we have identified the following main changes(called hereafter key factors) that could affect the costs of the implementation of the revised directive:

# Key factor

1 Limit values for heavy metals in sludge

2 Limit values for organic compounds in sludge

3 Pollution prevention policy

4 Limit values for heavy metals in soil

5 Obligation of treatment

6 Implementation of a quality assurance system

7 Extension of the scope to industrial sludge

8 Extension of the scope to Accession Countries

Table 18: Key factors affecting implementation costs of the revised directive

29 See working document on sludge (3rd draft) in appendix 1.1.

62

6.21 Scenarios definitionFour scenarios have been defined and evaluated. They correspond to:

• The business-as-usual scenario (scenario n°0)

• The implementation of the provisions that would be introduced in the revised directive30, assumingthat:- there is an efficient pollution prevention policy (scenario n°1), allowing the maximum quantities of

sludge to be used on land with additional constraints (treatment obligations, quality assurancesystem),

- there is no efficient pollution prevention policy (scenario n°2) resulting in the diversion of a part ofthe sludge currently spread on land to incineration, the rest of sludge being spread on land withadditional costs.

Each scenario is detailed in the table below:

Main scenarios

Options n°0(business-as-

usual)

n°1(PPP31)

n°2(no PPP)

1. Limit values on heavy metals (sludge)

2. Limits values on organic compounds (sludge)

Proposed requirements for the revision ofthe directive (short term, medium term

and long term values)

4. Pollution prevention policy (PPP)

Nationallegislation

Yes No

3. Limit values on heavy metals on soil Proposed requirements for therevision of the directive

5. Obligation of treatmentYes32

6. Implementation of a quality assurance system Yes33

Table 19: Definition of the scenarios

Besides, the �worst case scenario� has been also evaluated34, assuming that no sludge can meet the newrequirements of the revised directive if no pollution prevention policy is implemented.

First, we assessed the quantities concerned by each factor and the unit costs associated. Once allquantities and unit costs are identified, we will calculate the total costs (see chapter on results).

30 as given in the working document on sludge (3rd draft) see appendix31 PPP: Pollution Prevention Policy32 Yes for the quantities of sludge still recycled on land33 Yes for the quantities of sludge still recycled on land34 As for the other scenarios, the cost of the �worst case scenario� can be evaluated by two methods, assuming there

is a pollution prevention policy or not

63

6.22 Limit values for heavy metals in sludgeThe proposed limit values on heavy metals are the ones that could be introduced in the revised directive35

and coming into force as soon as the directive is implemented (short term), in the medium term(forecasted in 2015) and in the long term (forecasted in 2025).

Proposed limit values, compared with actual directive 86/278, are detailed in table below:

Proposed valuesMetal

mg / kg DMDirective

86/278/EEC Short termMedium term

target(about 2015)

Long termtarget

(about 2025)Cd 20-40 10 5 2Cr - 1000 800 600Cu 1000-1750 1000 800 600Hg 16-25 10 5 2Ni 300-400 300 200 100Pb 750-1200 750 500 200Zn 2500-4000 2500 2000 1500

Table 20: Proposed limit values (short, medium and long term) compared with directive86/278/EEC (mg/kgDM).

Expressed as a percentage of the lower limit value of directive 86/278/EEC, the proposed limit values areas follows:

Proposed values

mg / kg DMDirective

86/278/EEC Short termMedium term

target(about 2015)

Long termtarget

(about 2025)

Cd 100% 50% 25% 10%Cr NA NA NA NACu 100% 100% 80% 60%Hg 100% 63% 31% 13%Ni 100% 100% 67% 33%Pb 100% 100% 67% 27%Zn 100% 100% 80% 60%

Table 21: Proposed limit values (short, medium and long term) expressed as a percentage of thelower limit values of directive 86/278/EEC (mg/kgDM).

Quantities of sludge failing to meet regulatory requirements (called hereafter �sludge failing�) depend on:

- the severity of existing national legislation, compared to the proposed limit values: the stricter nationallegislation already is, the less it will be impacted by the proposed limit values (a country whosenational legislation is already stricter than the proposed new limit values would not be affected by theproposed limit values),

- the quality of sludge (the better the quality of sludge of one Member State is, the less quantity ofsludge will be diverted from recycling route.

35 see working document on sludge (3rd draft) in appendix

64

National limit valuesIn the table below, we estimated the severity of current national legislation by estimating the number oflimits on heavy metals that are less strict than the limit values that would be implemented in the newdirective36 .

Member State Short term Medium term Long termAustria 0 0-337 0-4 38

Belgium 0 2 239-440

Denmark 1 2 2

Finland 0 0 1

France41 2 6 7

Germany 1 5 7

Greece 6 6 6

Ireland 3 7 7

Italy 2 6 7

Luxembourg 7 7 7

Netherlands 0 0 0

Portugal 2 7 7

Spain 7 7 7

Sweden 0 0 1

UK 7 7 7

Table 22: Number of national limits on heavy metals less strict than the proposed new limit values(short, medium and long term). Source: calculated from regulatory sub-component report

Two cases are possible for Member States:

1 All national limits on heavy metals are already stricter than the proposed new limit values. In thiscase, the national legislation will not be affected with respect to this aspect. This applies toNetherlands, Finland and Sweden (for short and medium term limit values for heavy metal insludge), Austria and Belgium (for short term limit values only).

2 If national limits on heavy metals are less strict (totally or partially), then we need the detailedpercentile sludge quality distribution to evaluate the quantity of sludge failing to meet requirements.This is the case for all other Member States.

36 see working document on sludge (3rd draft) (annex 3, medium term and long term values)37 Austria: depends on the Länder.38 Austria: depend son the Länder.39 Flanders region40 Walloon region41 For Cadmium, limit values from January 1st, 2004 have been considered.

65

Sludge qualityThe quantity of sludge that would fail requirements has been estimated using a percentile-distribution(when available) of annual mean concentrations.

As the percentile distribution is available only for 5 Member States (FR, DK, AT, FI, UK), for one yearwithin the [1990 � 1997] period, three country categories have been defined according to their annualmean quality: when the percentile repartition is not available for one country, we consider the percentilerepartition of its category.

National sludgemean quality

category

Countries Data available on percentilerepartition of heavy metals

1

NetherlandsSwedenAustriaBelgiumDenmark

NoNoYesNoYes

2

FinlandFranceGermanyLuxembourgItalyGreeceSpain

Yes42

YesNoNoNoNoNo

3IrelandPortugalUK

NoNoYes

Table 23: Categories of countries according to available43 data on sludge quality. Source: adaptedfrom scientific sub-component report.

42 Sludge percentile repartition of Finland has not been further considered due to incoherent data between average

values and percentile repartition43 Current quality based on the most updated data available on sludge quality (refer to the technical and scientific

sub-component report)

66

Sludge quality evolution

During the last 20 years, sludge quality has considerably improved. Some examples are provided infigures below (source: scientific report)

0

500

1000

1500

2000

2500

3000

3500

1980 1985 1990 1995 2000

mg/

kg D

M

Zn

Cr

Ni (x10)

Pb (x10)

Cu (x10)

Cd (x100)

Figure 12: Decrease of heavy metals content in sewage sludge in Upper Austria, 1980 � 2000[Aichberger, 2000] concerns 80 to 140 rural, urban and industrial plants, of which capacities vary

between <1000 and 500 0000 inhabitants equivalent.

0

500

1000

1500

2000

2500

3000

3500

1977 1982 1987 1992

mg/

kg D

M

ZnCrNi (x10)Pb (x10)Cu Cd (x100)Hg (x100)

Figure 13: Decrease of heavy metals content in sewage sludge in Germany, 1977 � 1992/93 [ATV1996]

67

Cd

cont

ent i

n sl

udge

(mg/

kg D

M)

Figure 14: Evolution of the Cadmium content in the Nottingham, UK WWTP sludge since 1960.Source: Rowlands 1992 in Smith 1996.

Those figures show that, for most of the pollutants considered, after a significant improvement in the firstdecades, the level of pollutants is nearing a base level.

It has therefore been assumed that the sludge quality would be constant in the Member States over time,unless additional prevention pollution measures are taken.

More accurate assumptions would require statistical data on sludge produced in Member State, at least ona representative sample. Such detailed historical data is however not available yet in any Member State.

Quantities and percentage of sludge failingAccording to the methodology followed, the table below gives our assumptions on the maximumpercentage of sludge produced that exceeds any limit values for heavy metals in sludge (Cd, Cr, Cu, Hg,Ni, Pb, Zn), according to available information on sludge quality. These percentages are evaluated withthe available percentile repartition of sludge at national level in some countries44. For each heavy metal,data has been compiled on the concentrations in sludge by percentile.

We also consider that the percentile repartition of sludge recycled is the same as that of the sludgeproduced. This assumption is probably pessimistic and overestimates quantities and costs of sludgefailing, as sludge recycled should have a lower pollutant concentration than for other routes, due to morestringent regulatory requirements and more frequent quality controls. However, no quantitativeinformation was available to estimate sludge quality differences according to sludge routes.

44 year: UK 1996-1997, France 1992, Denmark 1990, Austria 1995

68

No PPP scenario PPPscenarioCate

goryRepresentative

countryBusiness as

usual45

Shortterm

Mediumterm Long term Worst case All

limits

1Denmark

Austria0% 10% 20%

50%

(40%46-60%47)100% 0%

2France 0% 10%48 30% 50% 100% 0%

3 UK 0% 20 % 50% 80% 100% 0%

Table 24: Percentage of sludge failing to comply with the proposed new limit values (on the basis ofavailable annual average sludge quality, No PPP option)

Therefore, if we combine the available information on national legislation and sludge quality, we obtainthe following percentages of sludge failing for each Member State:

No PPP scenario PPP scenarioMember State Sludge

quality type Short term Medium term Long term All limits

Austria 1 0% 20% 50% 0%Belgium 1 0% 20% 50% 0%Denmark 1 10% 20% 50% 0%Finland 2 0% 0% 50% 0%France 2 10% 30% 50% 0%Germany 2 10% 30% 50% 0%Greece 2 10% 30% 50% 0%Ireland 3 20% 50% 80% 0%Italy 2 10% 30% 50% 0%Luxembourg 2 10% 30% 50% 0%Netherlands 1 0% 0% 0% 0%Portugal 3 20% 50% 80% 0%Spain 2 10% 30% 50% 0%Sweden 1 0% 0% 50% 0%UK 3 20% 50% 80% 0%

Table 25: Quantities of sludge concerned by the proposed limit values (based on availableinformation on annual average sludge quality)

45 Percentage of sludge failing is zero in the business-as-usual scenario as we assume that all sludge recycled is in

compliance with national legislation on the recycling of sludge.46 Denmark47 Austria48 Observed data would be 5%. This has been increased to 10% to be coherent with data from category n°1.

69

On this basis, absolute quantities of sludge failing to comply with the proposed limit values (short,medium and long term), are as follows:

No PPP scenario PPP scenarioktDM/year short term medium term long term worst case All limits

Austria 0 14 34 68 0Belgium 0 9 24 47 0Denmark 13 25 63 125 0Finland 0 0 58 115 0France 77 230 383 765 0Germany 139 417 696 1 391 0Greece 1 2 4 7 0Ireland 17 42 67 84 0Italy 19 57 95 189 0Luxembourg 1 3 5 9 0Netherlands 0 0 0 110 0Portugal 22 54 86 108 0Spain 59 177 295 589 0Sweden 0 0 84 167 0UK 224 559 894 1 118 0EU 15 570 1 588 2 784 4 893 0% of total 12% 32% 57% 100% 0%

Table 26: Quantities of sludge failing to comply with the proposed new limit values to beimplemented in the revised directive (on the basis of available annual average sludge quality, ktDM

/year)

Quantities of sludge failing limit values on heavy metals are described in figures below, according to thevarious scenarios:

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

BAU

No PPP (S

hort

term)

No PPP (M

edium

term

)No P

PP (Lon

g term

)No P

PP (Wor

st ca

se)

PPP (all l

imits

)

sludge not failing limitvalues on heavy metals onsludge

heavy metals (in sludge)

Figure 15: Percentage of sludge failing new requirements on heavy metals in sludge in MS (short,medium and long term limits)

70

For quantities of sludge failing limit values on heavy metals, two scenarios are possible:

- specific pollution prevention measures are taken to reduce heavy metals loads in the sludge, reducingthe quantities of sludge initially failing to zero (PPP scenario n°1).

- no specific pollution prevention measure are taken: the quantities of sludge failing will not be fit foruse in agriculture, and will have to be disposed of by another route (No PPP scenario n°2),

Unit cost of switching from landspreading to incineration (No PPP scenario)Due to increasing restrictions on sludge landfilling in the coming years, we consider that the fraction ofsludge failing will be treated by incineration (mono- incineration or co-incineration with other wastes). Inthis case, costs will be related to the incineration of this fraction of sludge and savings with respect tolandspreading.

As the detail of sludge routes repartition within the �reuse� category and within the �incinerationcategory� is not available with homogenous data and precise definition among Member States, we willconsider the maximum estimated costs, corresponding to the switch from landspreading of semi-solidsewage sludge (route n°2) to mono-incineration (route n°6).

Average internal and external unitary costs in Member States of switching from route n°2 to route n°6 aregiven in table below:

�/t DM

Type of cost Nature of cost

#2(la

ndsp

read

ing

of se

mi-s

olid

)

#6 (M

ono

Inci

nera

tion)

Switc

h of

rou

te(r

oute

n°6

-ro

ute

n°2)

Investment and operationalcosts Internal costs 164 318 154

Loss of agronomic value Internal benefits -54 0 54Additional quantifiableExternalities (airborneemissions)

Net external costs -3 37 40

Total Net internal and externalcosts 107 355 248

Table 27: Average internal and external unitary costs of switching from landspreading (route n°2)to incineration (route n°6) in the Member States (source: unitary costs and benefits) � Euro/tDM

71

Sensitivity analysis and definition of non-complianceResults are very sensitive to the quantity of sludge not in compliance, since costs are directly proportionalto the quantities of sludge failing requirements. For instance, if the percentage of sludge failingrequirements increases from 20% to 30%, the quantities of sludge (and the related additional costs) willincrease by 50%.

Definition of non-compliance in the revised directive is as follows: �Sludge shall be assumed to conformto the concentration limit values for heavy metals, organic compounds, dioxin and micro-organisms if,for each concentration limit considered individually, the 90-percentile of the sample within a twelve-month period are at or below the threshold value and if the 10-percentile of the sample exceeds only onethreshold value by less than 50%.�

By lack of data concerning sample results within a twelve-month period, the quantity of sludge that wouldnot be in compliance has been estimated using a percentile-repartition (when available) of annual meanconcentrations.

A more precise approach, followed by WRc for the UK DETR, estimated the amount of sludge in the UKwhich would fail to comply with the various limit values which would be set in the revised directive,based on a database that contained the results of every sample analysed (and not only the annual mean).

This approach lead to a higher amount of sludge being diverted from the agricultural route: whereas lessthan 10% of sludge quantities in the UK had an annual mean average failing the proposed limits, almost20% to 40%49 of sludge was failing the requirements when using this methodology.

Therefore, the approach by annual mean seems to underestimate the quantities of sludge not incompliance with the exact definition.

A similar study50 was carried out in France in 2001 with the AGHTM (Association générale deshygiénistes et techniciens municipaux) restricted to a representative sample of around 60 wastewatertreatment plans in France. This study concludes that respectively 5%, 20% and 100% of sludge of thesample was failing limit values on heavy metals respectively in the short, medium and long term.

According to this study, the assumption made on the percentage of sludge failing limit values on heavymetals (see table n° 25) may be overestimated (by 5% to 10%) in the short and medium term but may beunderestimated in the long term (by 20%).

Therefore, we consider that the uncertainties associated with the percentage of sludge failing limit valueson heavy metals can be as high as +/- 30%.

6.23 Limit values for organic compounds in sludge

6.231 Objectives

The objectives of this chapter are to assess the quantities of sludge failing to reach the proposed new limitvalues on organic compounds and to assess the associated costs.

6.232 MethodologyThe same methodology is applied for organic compounds as for heavy metals.

49 20% estimated by WRc and 40% by the UK Environmental Agency depending on the database used and other

assumptions.50 AGHTM, France, F. Ducray and A. Huart, Impact du futur projet européen sur la valorisation des boues en

agriculture, campagne d�analyse sur les boues de STEP, présentation des travaux, réunion du 05/09/2001

72

In order to assess the percentage of sludge that would fail to reach the proposed limit values on organiccompounds, we analysed:

- the severity of legislation of each European country, and compared each legislative regime with theproposed new limit values which would be introduced in the revised directive51, (again, the stricter anational legislation already is, the less it will be affected by the revised directive).

- available data on concentration of organic compounds.

6.233 National regulationsThe following table compares the proposed new limit values for organic compounds with each nationallegislation in the Member States:

PCDD/PCDFs PCBs AOX LAS l DEHP p NPE q PAH r Toluene

ng TE/kg DM mg/kg DMDirective 86/276 NL NL NL NL NL NL NL NL

Proposed limitvalues 100 0,8 500 2 600 100 50 6 NL

Denmark- from 1/07/2000- from 1/07/2002

NL NL NL260013001300

1005050

503010

633

NL

Sweden NL 0,4 NL NL NL 100 3 5

Austria 100 a, b, d

50 f 0,2 a, b, d 500 a, b, f NL NL NL 6 f NL

Germany 100 0,2s 500 NL NL NL NL NL

France NL 0,8 m NL NL NL NL 2 � 5 n1.5 �4 o

NL

Other MemberStates k NL NL NL NL NL NL NL NL

a Lower Austriab Upper Austriac Burgenlandd Vorarlberge Steiermarkf Carinthia

k Except for Flanders where limit values for approximately30 organic compounds have been fixed

l Linear alkyl-benzene sulphonates,m Sum of 7 principal PCBs (PCB 28, 52, 101, 118, 138,153, 180)n Fluoranthene, Benzo(b)fluoranthene, Benzo(a)pyreneo When used on pasture landp Di (2-ethylhexyl)phtalateq Includes nonylphenolr Poly aromatic hydrocarbonss For each one of the six congeners

NL: No limit values

Proposed limit value more stringent than national limit value

Table 28: Proposed limit values for organic compounds in sludge (mg/kg DM) compared to thenational limit values (source: adapted from the regulatory sub component report)

51 see working document on sludge (3rd Draft) in appendix

73

This table shows that for every52 Member State, at least one proposed limit value on organic compound ismore stringent that the national limit value, mainly because proposed limit values concern new categoriesof organic compounds that are rarely addressed by national legislation..

Therefore, we need to analyse sludge quality to estimate the percentage of sludge failing newrequirements on organic compounds.

6.234 Sludge qualityAvailable data in Member States on organic compounds concentration in sludge is presented below:

PCDD/Fs PCBs AOX LAS DEHP NPE PAHng TE/kg DM mg/kg DM

Proposed limitvalues

100 0,8 500 2600 100 50 6

Austria 8,1-38 - - - - - -Belgium - - - - - - -

Denmark 0,7-55 <0,005-0,14 <0,02 374 24 8,1 1,8

Finland 0,006-0,018 0,038-0,243 - - 23-270 - 0,018�

11,9France - - - - - - -Germany 15-45 0,01-0,04 140-280 - 20-60 - 0,1�0,6Greece - - - - - - -Ireland - 0,067 - - - - -Italy - - - - - - -Luxembourg - - - - - - -Netherlands - 0,008 - - - - 9,7Portugal - - - - - - -Spain 64 - - - - - -Sweden 0,02-115 0,1 - - 25-660 22,8 1,8UK 9-192 0,01-21 - - - - 1-10

-: Not available

Table 29: available data on organic compounds concentration in sludge � mg/kg DM unlessotherwise stated (Source: Scientific sub-component report)

This table shows that, for the same compound category, concentrations are highly variable, not onlyamong Member States, but also among waste water treatment plants in each Member States: high valuescan be more than 100 times higher than low values.

This could be explained either by different organic compounds concentrations among wastewatertreatment plants and/or by a lack of harmonised measurement methodologies. For instance, no method isproposed in the revised directive53 for measurement of LAS, DEHP, NPE or PCDD/F.

Wide ranges often exceed proposed limit values, and sometimes (as in the Netherlands for PAH) meanvalues exceed these limit values. In this case more than 50% of the sludge would not meet limit values.

52 With the possible exception at Flanders53 See working document on sludge (3rd draft), Annex VII on sludge for AOX, LAS, DEHP, NPE, PCDD/F

74

In addition, the study54 performed by the UK Department of the Environment, Transport and Regions,Water Quality Division concluded that almost all sludge produced in the UK would fail to meetrequirements, mainly because of limit values on PAHs, PCDD/Fs, phthalate, nonylphenol and LAS, eventhose originating from rural/domestic WWTPs.

In France, the recent study55 carried out by the AGHTM found, based on a representative sample of 60treatment plants, that more than 50% of the sample considered would fail limit values on organiccompounds, in particular NPE.

Therefore, without more detailed information on sludge quality, we will consider that the percentage ofsludge failing limit values on organic compounds will be as high as 50% for all Member States56 .

However, a significant part of the sludge failing limit values on organic compounds may also fail limitvalues on heavy metals.

To avoid double counting quantities of sludge failing both organic compounds and heavy metals limitvalues, we made assumptions regarding the relationship between sludge failing limit values on heavymetals and organic compounds.

In this study, we consider that the origin of heavy metals and organic compounds pollutants in sludge aredifferent. In this case, sludge failing limit values on heavy metals and organic compounds areindependent57.

Therefore, the percentage of sludge failing limit values on organic compounds only (and not on heavymetals) will be equal to 50% of the percentage of sludge not failing limit values on heavy metals.

For example, if the percentage of sludge failing limit values on heavy metals equals 20%, then :

� Percentage of sludge not failing limit values on heavy metals equal 1-20% = 80%

� Percentage of sludge failing limit values on organic compounds equals : 50% x 80% = 40%

� Therefore, percentage of sludge failing limit values on organic compounds or on heavy metals equals20% + 40% = 60%

54 UK DETR- Lancaster University , December 2000, Organic Contaminants in Sewage Sludge, a Survey of UK

Samples and a Consideration of their Significance55 AGHTM, F. Ducray and A. Huart, Impact du futur projet européen sur la valorisation des boues en agriculture,

campagne d�analyse sur les boues de STEP, présentation des travaux, réunion du 05/09/200156 Due to the lack of reliable information on organic compounds, no differentiation can be made among Member

States as it was done for heavy metals.57 More precise assumptions would require the existence of a common database with the heavy metals and organic

compounds percentile repartition, which is currently not available in any Member State.

75

Therefore, the total percentage of sludge failing the new requirements on heavy metals and organiccompounds is indicated in the Figure below:

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%BAU

No PPP (S

hort

term)

No PPP (M

edium

term

)No P

PP (Lon

g ter

m)No P

PP (Wor

st ca

se)

PPP (all l

imits

)

sludge not failing limitvalues on sludge

organic compounds (insludge)


Figure 16: percentage of sludge failing limit values on heavy metals and organic compounds insludge according to the various limit values (short term, medium term, long term)

Data used in the figure above are detailed in the table below :

No PPP PPP

Quantities of sludge failing (ktDM/year)limit values on

BAU

Shortterm

Mediumterm

Longterm

Worstcase

alllimits

Heavy metals (in sludge) 0% 12% 32% 57% 100% 0%

Organic compounds (in sludge) 0% 44% 34% 22% 0% 0%

Total sludge failing limit values in sludge 0% 56% 66% 79% 100% 0%

Table 30: Percentage of sludge failing proposed limit values on heavy metals and organiccompounds in sludge

76

The UK DETR study58 considered that composting would reduce the concentration of most organiccompounds below the limit. The ICON study59 confirmed that aerobic sludge treatment (such ascomposting) would destroy most of the LAS, NPE or DEHP. However, persistent organic compoundssuch as PAHs, PCBs, PCDD/Fs would probably not be sufficiently destroyed by composting, leading usto a more prudent approach.

Therefore we will assume, as for limit values on heavy metals, that two scenarios are possible:

- specific pollution prevention measures are taken to reduce organic compounds loads in the sludge,which enable in fine the same quantities of sludge initially failing to be spread on land (PPP scenarion°1).

- either no specific pollution prevention measure are taken: the quantities of sludge failing will not be fitfor use in agriculture, and will have to be disposed of by another route (No PPP scenario n°2).

Uncertainties

Uncertainties concerning the quantities of sludge failing proposed limit values on organic compounds arevery uncertain, considering the general lack of basic knowledge in this field (for instance averageconcentration on organic compounds).

58 UK-DETR-University of Lancaster, Organic contamination in sewage sludge : a survey of UK samples and a

consideration of their significance, December 2000.59 European Commission-IC Consultant, Pollution in Urban Water and Sewage Sludge presentation, Sludge

conference, October 2001

77

6.24 Pollution prevention policies and sludge quality

The evolution of sludge quality over time depends on the assumptions made regarding the efficiency ofthe pollution prevention policy (PPP). The two options that were considered are the following:

- important steps are taken to implement a pollution prevention policy that improves sludge quality andallows the maximum quantities of sludge to be used on land (scenario n°1).

- no effort is made, and the sludge quality remains similar to the current sludge quality (scenario n°2).

Note: Pollution prevention may be implemented through a variety of measures and policy. We assumedthat additional cost of pollution prevention policy would be totally supported by the new requirements onthe use of sludge, though pollution prevention may be the consequence of several regulation (for instancethe water framework Directive or the IPPC directive).

6.241 Sources of pollutionThe sources of potentially toxic element and organic compounds contamination in the wastewater systemhave been identified as originating from60

- domestic wastewater,

- commercial effluents,

- urban runoff.

The importance of each category (measured by the % of total input) is detailed in table below:

Heavy metal CommercialWastewater

DomesticWastewater

UrbanRunoff

Cd 30-60% 20-40% 3-40%Cr 35-60% 2-20% 2-20%Cu 3-20% 30-75% 4-6%Hg 50-60% 4-5% 1-5%Ni 30% 10-50% 10-20%Pb 2-20% 30-80% 30%Zn 5-35% 30-50% 10-20%

Table 31: Provisional potentially toxic element load from different sources entering urbanwastewater in EU countries (% of total input) Source: ICON 2000. For each metal, the major

contributor is highlighted in grey.

60 Source: ICON, 2000

78

Organiccompound

CommercialWastewater

DomesticWastewater

UrbanRunoff

LAS High High LowNPE High High Low

DEHP High Medium LowPAHs Low Low HighPCBs Low Low High

PCDD/Fs Low Low HighPharmaceuticals High High Low

Table 32: Importance of sources of organic compounds (commercial, domestic and urban). Source:ICON 2001. High contributors are highlighted in grey.

Measures of Pollution prevention

The main sources, priority measures and recommendation of the ICON report is detailed for all categoriesand summarised in table below:

Source Pollutantsconcerned

Main sources Priority measures and recommendations

All All

- Domestic (see below)- Commercial (see below)

- Improve knowledge and information onsources on local level

- Regulatory, economic, voluntary andeducational measures or instrument

Commercial

CdCrHgNi

LASNPE

DEHP

- health establishments (Hg forinstance)

- manufacturing industry- hotel/catering

- Industrial on site pre-treatment (largeindustrials)

- process reformulation ( source reduction)

Domestic

CuPbZnNi

LASNPE

- Body care products- Pharmaceutical- Cleaning products- Liquid wastes (e.g. paint).- Plumbing (for Cu for hard water

area and Pb if used for drinkingwater)

- Proper disposal of household waste- Reduce metal content in product (may be

impractical)- Product re-formulation- Eco-labelling- Voluntary collection schemes (liquid

waste)

Run-off

PAHs,PCBs,

PCDD/FCd, Pb

- Rain run-off,- Surface degradation- Roads and vehicle emissions

(brake, tire)

- Source reduction for primary sources oforganic pollutants (incineration,heating�)

Table 33: Category, sources and priority measures for reducing metal discharges into urbanwastewater. Source: adapted from ICON, 2001, Pollutant in urban waste water and sewage sludge

6.242 Steps of pollution prevention

Steps of pollution prevention may be separated as follows:

79

Steps Main Costs Nature of costs Stakeholder supporting the cost

1Main polluter identification anddischarge convention negotiationwith industrial operators

Time spent by local authorities Local authorities in charge ofsewage sludge quality

2 Reduction of pollution loads

Implementation of onsiteindustrial waste water treatmentplans or pollution preventiontreatment systems (ionexchange�)

Industries

3 Reduction of pollutant loads Production substitution Producers (industries) andproducts users

4 Reduction of primary sourceemissions Air discharge limit values Primary source operator

Table 34: Main costs, nature and stakeholder supporting the cost of pollution prevention

6.243 Costs of pollution prevention

Very little information is available in Member States on pollution prevention and in particular on costs.Some costs were identified in the UK by the DETR and WRc (for heavy metals) through strongassumptions that are detailed below.

Estimation of pollution prevention costs for industrial sources of metals in the UK: source DETR-WRc, March2001

This study estimated costs associated with the reduction of heavy metals discharges so as to maintain fullcompliance with the proposed values in the short, medium and long term of all sludge that is currentlyused in agriculture.

This estimate was made by using the UKWIR61 database on sludge quality, which contains the results ofevery sample of sludge that was analysed for heavy metals in the UK over a recent one-year period,broken down by Water Company.

For each site in the database and for each metal giving rise to a compliance failure, the required reductionto maintain full compliance was calculated. It was then assumed that the site concerned would have toremove that level of that metal plus 50% to ensure compliance (costs do not include costs of pollutantresearch by local authorities).

The following assumptions were made:

- The reduction of discharge of metals by industries would be sufficient to maintain compliance with thelimits,

- Number of industries concerned (and costs) is proportional to the total quantity of metal to be removedfrom the sludge,

- Each industry would reduce the concentration of heavy metals by 90% with ion exchange technology.

- A typical industry was considered to discharge 100 m3/day, with a 5mg/l concentration of heavymetals.

61 UKWIR: UK Water Industry Research

80

Following this methodology, the resulting estimates are presented in the table below:

Levels Shortterm

Mediumterm

Longterm

Worstcase

Costs (Millions �/year) 68 107 195 NA% of sludge �failing� in the UKwithout a PPP 18% 50% 91% 100%

Quantities of sludge �failing�(tDM/year) in the UK 241 670 1220 1 340

Unit cost per sludge failing (�/tDM)without a PPP 281 160 160 NA

Table 35: Pollution prevention costs supported by industrials in the UK (source DETR-WRc, 2001)

6.244 Limits of the evaluationHigh uncertainties are linked with these results. In particular:

- assuming that the reduction of discharge of metals by industries would be sufficient to maintaincompliance with the limits simplifies a complex issue and will probably underestimate the costs ofpollution prevention, in particular those linked with domestic sources and run-off.

- the technology used (ion exchange) is expensive and may overestimate the costs.

- these pollution prevention costs do not concern organic compounds, which may be probably requirespecific and costly additional measures.

- these costs do not include costs supported by local authorities to identify sources of majors pollutersand, in case of industry, negotiate conventions.

6.245 Extrapolation of the results to other Member States

Pollution prevention for heavy metals

It can be assumed, as per the UK study, that the cost of pollution prevention is proportional to the quantityof metal that must be removed from the sludge.

However, the quantity of metal that must be removed from sludge depends both on the quantity andquality of the sludge. As the detailed quality of sludge is not known with enough reliability and precisionin other Member States, we cannot use the same methodology for other European countries.

Nevertheless, to obtain an order of magnitude of these costs in other Member States, we will consider thatquantities of metals to be removed will depend only on the quantity of sludge failing requirements (andnot on the sludge quality).

Therefore, we will consider that the ratio (unit cost / tDM of sludge failing without a pollution preventionpolicy) will be constant among Member States.

In the UK- WRc study, this ratio varies between 160 and 280 Euro per ton (DM) of sludge failing,depending on the limits (see table above). We will consider in the rest of the report an average value of200 Euro/tDM.

81

Pollution prevention for organic compoundsAs no data was found concerning organic compounds pollution prevention, we used the samemethodology and ratio than for heavy metals (200 Euro / tDM of sludge failing limit values on organiccompounds).

As for heavy metals, high uncertainties are linked with these costs. In particular:

- these costs may be underestimated as domestic sources or run-off can represented a high source ofpollution, in particular for PAHs, PCBs or PCDD/Fs.

- these costs may be overestimated because other policy measures may reduce pollutants from importantsources (IPCC directive, product substitution�).

Pollution prevention for pathogens

It was assumed that the removal at source was not possible for pathogens, because they are due to normalhuman biological activity.

Pollution prevention for heavy metals in soilIt was assumed that the removal of metals in the soil was not feasible at reasonable cost.

Prevention pollution supported local authoritiesNo national information was found in Member States concerning costs of pollution prevention supportedby local authorities.

Therefore, we used the ratio of 10 Euro/tDM, based on figures reported from two case-studies62,assuming that pollution prevention requires one full-time employment for identifying sources ofpollution, negotiating conventions with industrials and controlling industrial discharges for a large wastewater treatment plant (200.000 PE, producing around 4.000 tDM/year).

62Case of the SAN d�Evry (Syndicat d�Agglomération Nouvelle) quoted by the French Environmental Ministry and

the Communauté d�Agglomération d�Hénin Carvin, France, 2001.

82

6.25 Limit values for heavy metals in soilAs limit values for heavy metals in soil would lowered compared to directive 86/278/EEC (see tablebelow), a greater proportion of soil might not meet the legal requirements to receive sludge.

mg/kg DM86/278/EEC

Directive6<pH<7

Proposed values6<pH<7 (annex V)

Cd 1-3 1

Cr - 60Cu 50 � 140 50Hg 1 � 1,5 0,5Ni 30 � 75 50Pb 50 � 300 70Zn 150 - 300 150

Table 36: Comparison of proposed limit values on heavy metals in soil with directive 86/278/EEC(6<pH<7), (mg/kg DM).

6.251 ObjectiveThe objectives of this chapter are to assess the proportion of soil that might not meet the legalrequirements to receive sludge and to evaluate associated costs.

6.252 Methodology

The proportion of soils failing requirements depends on:

- the severity of the existing legislation: the stricter a national legislation already is, the less it will beimpacted by the revised directive (i.e. a country whose national legislation is already stricter than theproposed new limit values would not be affected by it),

- the heavy metal concentration of soils (the lower the heavy metals concentration of soils of oneMember State is, the less surface area and the less quantity of sludge will fail to meet requirements).

6.253 National regulations

Member States have been categorised into 4 categories (A, B, C and D) according to the severity of theirnational regulations concerning heavy metal levels in soils. The severity of national legislation has beenassessed by the number of limit values (heavy metals) in soil that are less stringent than the proposedones63.

63 See working document on sludge, 3rd draft

83

Category Countries

Number of limit values onheavy metals in soil less

stringent than the proposedones

Metals ofconcern

% of soil failingrequirements

A

DenmarkIrelandNetherlandsSpainSweden

0 No metal 0%

BFinlandAustria64

BelgiumGermany

1 Cd, Cr, Hg

C FranceItaly 2-3 Cd, Cr, Ni Zn

DLuxembourgPortugalGreeceUK

6-7 All

Depends onconcentration of

heavy metals in soil

Table 37: Categories of countries according to the current severity of national legislation on soilquality. Source: Regulatory sub-component report.

Two cases are possible for Member States:

1. All national limits for heavy metals in soil are already stricter than the proposed ones. In this case,this aspect will not affect national legislation. This applies to countries of category A (Denmark,Ireland, Netherlands, Spain, and Sweden).

2. Some (or all) national limits on heavy metals in soil are less stringent than the proposed ones - wethen need to evaluate the percentage of soil that would fail the proposed limit values usinginformation on the average content of heavy metals in sludge.

6.254 Heavy metals content in soilsData on heavy metals content of soil (from topsoil sample) is available only for three European countries(France, Germany and United Kingdom)65. The comparison of these data with the proposed new limitvalues requires an assessment of the percentage of soil samples analysed that are over the limits for eachmetal taken separately. If we consider the limit values of all metals together, two assumptions can bemade:

- Exceedence occurs for all heavy metals at the same place. Then the quantity of land failingrequirements is the maximum value of each of the metals considered individually (minimalassumption).

- Exceedence occurs at different places. Then the quantity of land failing requirements is the sum ofeach proportion of land considered individually (maximum assumption).

64 Depends on the Länder65 Heavy Metal (Trace Element) Contents of European Soils � Results of Preliminary Evaluations for 4 memberstates published by the Joint Research Centre of the European Commission.

84

MemberStates

% of land samples failing foreach metal taken

separately[estimated from JRC 2000]

% of land failing forall66 metals

[min and max]

France 5% (Pb, Hg)10%(Cd, Cu, Ni, Zn, Cr67)

10%-60%

Germany 5%(Hg)10% (Cd, Cu, Cr, Ni, Zn)15% (Pb)

15%-70%

UnitedKingdom

15% (Cu, Ni)20% (Pb, Zn, Hg68)25% (Cd, Cr)

25%-100%

Table 38: Estimated proportion of soil failing to comply with the limit values on heavy metals(metals taken individually). Source: JRC 2001

This methodology leads to broad ranges of value of land failing requirements for all metals.

The �Regulatory Impact Assessment for the Proposed Revisions to the Sludge to Land� made by WRchas concluded (using a national database on soil quality) that 40% of the totality of agricultural land in theUnited Kingdom would not be available for sludge recycling.

As the case of UK leads to higher percentage of land failing than for France or Germany, we considerthat, for countries other than the UK, only 30% of land would fail.

Based on this result, we consider the following percentage of land failing for the three countries:

Member States% of failing land for

all metals[min and max]

% of failing landconsidered

France 10%-60% 30%Germany 10%-70% 30%United Kingdom 25%-100% 40%

Table 39: Estimated proportion of soil failing to comply with the limit values on heavy metals (allmetals taken together)

According to these assumptions, percentages of soil and sludge failing to meet proposed requirements onsoils used for the purpose of this study are presented below:

66 All metals: Cd, Cr, Cu, Hg, Ni, Pb, Zn.67 Pessimist assumption (No data available on Cr)68 Pessimist assumption (No data available on Hg)

85

Category Countries % of failing landconsidered

A


0%

BFinlandAustria69

BelgiumGermany

30%

C FranceItaly 30%


40%

Table 40: Estimated proportion of failing soil (%)

If a soil is not available for landspreading, then the water operator can:

- either find a new area for landspreading or;

- withdraw the quantities of sludge concerned from landspreading.

If the operator had to find new area for landspreading, than the water operator would face additional costsand new negotiation with farmer and probably more reluctance from neighbours and local population.According to the Syprea and the study conducted in the UK by the DETR-WRc70, if the area failing newlimit values on soil is significant, the operator would probably withdraw these quantities fromlandspreading. In this case, as for limit values in sludge, we will assume that quantities of sludgewithdrawn from landspreading will have to be incinerated.

69 Depends on the Land70 The DETR-WRc took a even more conservative assumption, considering that if, for one operator, the % of soil

failing is locally over 50%, than the water operator would withdraw completely from the landspreading route.

86

Category Countries % of failing sludgeconsidered

A


0%

BFinlandAustria71

BelgiumGermany

30%

C FranceItaly 30%


40%

Total EU 15 25%

Table 41: Estimated proportion failing soil and related percentage of failing sludge

However, a significant part of the sludge failing to comply with limit values in soil may fail at the sametime limit values in sludge.

To avoid double counting quantities of sludge failing both limit values in soil and in sludge, we considerthat sludge failing limit values in soil and sludge are independent.

Therefore, the percentage of sludge failing to comply with limit values in soil only (and not limit values insludge) will be equal to 25% of the percentage of sludge not failing limit values in sludge.

For example, if the percentage of sludge failing limit values in sludge equals 60%, we consider that theadditional percentage failing limit values on soil will be equal to 10% = 25% x (1-60%).

71 Depends on the Land

87

Therefore, the total percentage of sludge failing the new requirements on sludge (heavy metals andorganic compounds) and on soil is indicated in the figure and graph below:

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

BAU

No PPP (S

hort

term)

No PPP (M

edium

term

)No P

PP (Long

term

)No P

PP (Wor

st ca

se)

PPP (all l

imits

)

sludge not failing limit valueson sludge ans soil

limit values on heavy metals(on soil)

organic compounds (insludge)


Figure 17: percentage of sludge failing limit values in sludge and soil according to the variousscenarios

Figures used in the figure above are detailed in table below:

No PPP PPP

Quantities of sludge failing (ktDM/year)limit values on

BAU

Shortterm

Mediumterm

Longterm

Worstcase

alllimits

Heavy metals (in sludge) 0% 12% 32% 57% 100% 0%

Organic compounds (in sludge) 0% 44% 34% 22% 0% 0%

Heavy metals (on soil) 0% 11% 8% 5% 0% 25%

Total sludge failing 0% 67% 74% 83% 100% 25%

Table 42: Percentage of sludge failing proposed limit values in sludge and soil according to thevarious scenario

88

6.255 UncertaintiesUncertainties are high with respect to this key factor due to the fact that:

- data concerning concentration in soils are available only partially and only for three Member States,

- a precise evaluation covering all metals together is only possible when a database on soil quality isavailable (as is the case in the UK).

In addition, these costs may be underestimated, as having a high proportion of soil failing limit values onheavy metals (for instance higher than 50% for one operator) might influence an operator to withdrawcompletely from the landspreading option.

89

6.26 Obligation of treatment

6.261 Objective

The objectives of this section are to assess quantities of sludge not meeting the new requirementsconcerning treatment obligations72 and the associated costs.

6.262 Methodology

In order to assess the percentage of sludge failing to comply with this criteria, we:

- study the level of legislation of each European country, and compare this with the requirements thatwould be introduced in the revised directive,

- analyse the existing situation in terms of sludge treatment in each European country.


Countries such as Belgium (Flanders), Denmark, Finland, Germany, Greece, Italy, the Netherlands,Portugal and Spain prohibit the use of untreated sludge, while other countries have no specificrequirements concerning the treatment of sludge.

However, the definition of �treated� or �untreated sludge� is not as precise as that which would beintroduced in the revised directive73 and therefore, it is possible that the prospect of new treatmentobligations has not been fully anticipated by most of the Member States.

In Finland, sludge must be treated by digestion or lime stabilisation before being used in agriculture. Weconsider therefore that no sludge will fail requirements with regard to treatment obligations in Finland.

In the UK, according to WRc and the DETR, a new regulation should come into force before 2005 withsimilar specifications for treatment obligations. Therefore the additional costs of the proposed newrequirements in the UK should be zero.

72 As defined in the working document on sludge, 3rd draft.73 See working document on sludge, 3rd draft

90

6.264 Existing situation in terms of sludge treatmentThe proportion of sludge that has �no stabilisation�74(i.e. : other than anaerobic and aerobic digestion,lime addition, composting) represents around 25% of the total sludge amount produced in the EU, withvalues varying from 0% to 89% among Member States, as detailed in table below:

Countries % of sludge with notreatment

Austria 30%Belgium 25%Denmark 29%Finland 0%France 20%Germany 21%Greece 0%Ireland 89%Italy 27%Luxembourg 20%Netherlands 12%Portugal 10%Spain 10%Sweden 30%UK 0%EU 15 25%

Table 43: Percentage of sludge production with �no treatment�. Source WRc-SEDE, 199475

If we assume that all categories of treatment other than �no stabilisation� (i.e. anaerobic and aerobicdigestion, lime addition and composting) are conducted in compliance with definitions given in therevised directive76, then the quantities of sludge failing requirements are the same as those within the �notreatment� category.

74 According to the study SEDE and WRc; Waste management � Sewage sludge, Part 1, Survey of sludge

production, treatment, quality and disposal in the European Union, October 1994. No update has been publishedthen.

75 No update had been published since then.76

91

6.265 ResultsConsidering previous assumptions, quantities of sludge concerned by the obligation of treatment andrequiring additional treatment are detailed by country in the following table :

Quantities of sludgeconcerned (k tDM/year)

No PPP scenario PPPscenario

Countries % of sludgeconcerned77

*BAU

Shortterm

Mediumterm

Longterm

Worstcase

All limits

Austria 30% 0 10 8 5 0 20Belgium 25% 0 4 3 2 0 8Denmark 29% 0 16 15 9 0 36Finland 0% 0 0 0 0 0 0France 20% 0 48 37 27 0 107Germany 21% 0 92 72 51 0 204Greece 0% 0 0 0 0 0 0Ireland 89% 0 30 19 7 0 75Italy 27% 0 16 13 9 0 36Luxembourg 20% 0 1 0 0 0 1Netherlands 12% 0 7 7 7 0 13Portugal 10% 0 3 2 1 0 8Spain 10% 0 27 21 15 0 59Sweden 30% 0 25 25 13 0 50UK 0% 0 0 0 0 0 0EU 15 25% 0 279 221 145 0 618

% of total recycled 0% 6% 5% 3% 0% 13%

Table 44: Quantities of sludge concerned by the obligation of treatment (ktDM/year)

77 Sludge concerned by the obligation of treatment and requiring additional treatment. The percentage is calculated

on the percentage of sludge still spread on land (i.e. percentage of sludge not failing previous requirements onsludge and soil)

92

Unit costIt was assumed that the fraction of sludge that is not yet stabilised would have to be stabilised. One of themost practical courses of action would be to treat the sludge by digestion or addition of lime. For thispurpose, we estimate the costs as being those involved with switching from route n°2 (landspreading ofunstabilised sludge) to route n°3 (landspreading of stabilised sludge). In this case, additional internal costs(average EU 15) are 47 Euro/tDM 78.

Additional internal benefits and external costs can be neglected (see chapter on unit costs).

UncertaintiesUncertainties linked with the unknown quantities of sludge which are subject to treatment obligations aredue to the absence of knowledge of quantities treated according to the type �conventional�, �advanced�,as defined by the working document on sludge, 3rd draft.

Therefore, if the quantities of sludge not treated with �conventional� or �advanced� treatment are larger(respectively smaller) than the quantities of sludge with �no treatment�, then quantities of sludgeconcerned by the obligation of treatment and thus associated costs are overestimated (respectivelyunderestimated).

6.27 Implementation of a quality assurance system

6.271 ObjectiveThe objective of this section is to assess the cost of the implementation of a quality assurance system(certification, information requirement, and analysis�.) as it could be required in the revised directive79.


Member States have generally transposed into national legislation the information requirement of thecurrent 86/278 Directive, whereas certification procedures, such as product or service qualitycertification, are not specified in national legislation on the use of sludge for the time being. (seeregulatory sub-component report).

Therefore, we assume that operating costs will increase in every Member State, except for Sweden, whereit has been agreed to set up a voluntary quality certification scheme (see regulatory sub componentreport).

78 See chapter on unit costs and benefits79 See working document on sludge, 3rd draft.

93

6.273 Results

Quantities concerned

Quantities of sludgeconcerned (k tDM/year)

No PPP scenario PPPscenario

Countries % of sludgeconcerned80

BAU

Shortterm

mediumterm

Longterm

worstcase

all limits

Austria 100% 0 34 27 17 0 68Belgium 100% 0 16 13 8 0 33Denmark 100% 0 56 50 31 0 125Finland 100% 0 40 40 20 0 81France 100% 0 241 187 134 0 536Germany 100% 0 438 341 243 0 974Greece 100% 0 2 2 1 0 5Ireland 100% 0 34 21 8 0 84Italy 100% 0 60 46 33 0 133Luxembourg 100% 0 3 2 2 0 6Netherlands 100% 0 55 55 55 0 110Portugal 100% 0 30 19 8 0 76Spain 100% 0 265 206 147 0 589Sweden 0% 0 0 0 0 0 0UK 100% 0 268 168 67 0 671EU 15 0 1 543 1 178 775 0 3 489% of total quantities of sludge

recycled0% 32% 24% 16% 0% 71%

Table 45: Quantities of sludge concerned by the quality insurance (ktDM/year)

Unit costAccording to the SYPREA81, implementing quality assurance system (certification, informationrequirement, and analyses�.) would increase operation costs by 10% to 15% on average. Taking intoaccount all these elements, we will consider that the increase of operating costs for landspreading isaround 15 Euro/tDM, (including sludge analyses).

80 % of sludge still meeting proposed limit values in sludge or soil81 Syndicat des professionnels du recyclage agricole French professional organisation for the recycling of wastes to

land

94

Unit costs of sludge analysisHere we estimate the maximum costs of sludge analyses, before conducting a more precise investigationby Member State. For this purpose, it is necessary to assess the costs of analyses that would be required inthe revised directive. These are presented below.

Quantities of sludgeproduced

(tDM/year/plant)Minimum number of analyses per year Total costs

(�/tDM)

low range highrange

Agronomicparameters

Heavymetals

Organiccompounds

Dioxins Micro-organisms

Total Total costs(�)

low range highrange

<250 250 2 2 0 0 2 6 471 >1,9 1,9250 1 000 4 4 1 0 4 13 1 957 7,8 2,0

1 000 2 500 8 4 2 0 8 22 3 695 3,7 1,52 500 4 000 12 8 4 1 12 37 7 761 3,1 1,94 000 >4 000 12 12 6 1 12 43 10 011 2,5 <2,5Unitary costs of

analysis(� per sample)

40 55 1 016 1 094 141

Table 46: Sludge analysis costs and costs of analysis by type of sewage plant (Euro/tDM)

According to these estimations, costs of sludge analyses are around 3 �/tDM (between 1,5 and 7,8 �/tDMaccording to the size of the waste water treatment plant), thus representing less than 25% of the cost ofquality assurance.

6.28 Inclusion of industrial sludge

6.281 ObjectiveThe objective of this section is to assess the costs related to the possible new requirements of the reviseddirective concerning industrial sludge.

6.282 MethodologyFor this purpose, we:

- analysed the level of requirements of the legislation in each Member State, and compared each onewith the possible provisions of the revised directive82,

- analysed the existing situation in terms of sludge treatment in each Member State, by comparison withnational provisions and the provisions that could be introduced in the revised directive.

82 See Working Paper on sludge, 3rd Draft

95

6.283 National regulationsAccording to the national legislation of each Member State, we can categorise each of them in one of thethree following categories (Source: Regulatory report)

- Category 1: Countries that have a similar regulation concerning industrial and urban sludge (Denmark,Belgium, Italy, and the Netherlands),

- Category 2: Countries that have regulations other than the one concerning sewage sludge, mostly localregulations (Austria, Germany, Ireland, Spain, Sweden, UK, Finland, France),

- Category 3: Countries that have no specific regulation concerning disposal of sewage sludge (Portugal,Luxembourg, Greece).

As in the Netherlands, all limit values for heavy metals both for sewage and industrial sludge are stricterthan those that could be introduced in the revised directive, it may be assumed that there are no quantitiesof industrial sludge concerned and no costs associated in this country.

6.284 Limit values on heavy metals in sludgeExtension of the revised directive to sludge produced by industrial sectors83 should strongly increase thequantity of sludge covered by the directive: sludge production of the industrial sector is estimated to be4 Mt of DM per year 84, that is almost half of the one of urban sewage sludge.

In most countries surveyed by WRc-SEDE [2001], the available information on the quality of industrialsludge recycled to land is limited and is based on very limited sets of samples analysed for a limited rangeof parameters.

We have chosen here to analyse the information by industrial sectors and by countries. Data concerningthe composition of sludge, by industrial sectors, are available in the �Survey on waste spreading on land�,[WRc, 2001]. The available data concerning the quality of industrial sludge are only based on the heavymetals values (no information on organic compounds).

The industrial sectors have been classified into four categories, according to the �Survey of wastes spreadon land � draft final report� (January 2001) from WRc:

83 Sectors listed in Annex VIII of the draft working document84 Source: WRc � SEDE, June 2001. Data does not take into account missing information that is not available for

some countries or some industrial sectors.

96

kt DM Abattoirs Food anddrink

Pulp andpaper

Leather,textile andtanneries

Total % of total

Austria - - - - - -Belgium 3 218 51 1 273 7 %Denmark 10 50 0 0 60 2 %Finland - 100 - - 100 2 %France 136 1 118 740 36 2 030 49 %Germany - 795 - - 795 19 %Greece - - - - - -Ireland 18 82 0 0 100 2 %Italy 21 138 13 1 173 4 %Luxembourg - - - - - -Netherlands - - - - - -Portugal - - - - - -Spain - - - - - -Sweden - 164 - 0 164 4 %UK 300 93 24 0,7 418 10%Sludge production(tDM/year) 488 2 758 828 38,7 4 112 100%

% of total 12 % 67 % 20 % 1 % 100 %

Table 47: Industrial waste recycled to land in Member States, by countries and by industrialsectors. Source: SEDE - WRc 2001, (ktDM/year)

As no information is available on the detailed composition of industrial waste, we will assume that allwaste spread on land is composed of sludge.

Table below gives estimate on the maximum percentage of industrial sludge produced that exceeds thelimit values for heavy metals in sludge, by industrial sectors and according to available information onindustrial sludge quality.

Industrial sectors Problematicmetals

Shortterm

Mediumterm

Longterm

Worstcase

Abattoirs Hg 0% 0% 5% 100%Food and drink Cd, Hg 0% 5% 10% 100%Pulp and paperwaste sludge Cd 0% 0% 10% 100%

Leather andtannery - 0% 0% 0% 100%

All sectors 0% 3% 9% 100%

Table 48: Percentage of industrial sludge failing proposed limit values on heavy metals - source:calculated from information in SEDE-WRc [2001]

97

6.285 ResultsFor each country and by sector, we multiplied the quantities of industrial sludge by the relevantpercentages. Adding the results for each country, we obtained the total quantity of industrial sludgeconcerned. The quantities concerned are summarised below:

Quantities of sludge concerned(tDM)Member States

short term medium term long term worst caseAustria - - - -Belgium 0 11 27 273Denmark 0 3 6 60Finland 0 5 10 100France 0 56 193 2 030Germany 0 40 80 795Greece - - - -Ireland 0 4 9 100Italy 0 7 16 173Luxembourg - - - -Netherlands - - - -Portugal - - - -Spain - - - -Sweden 0 8 16 164UK 0 5 27 418Total EU 15 0 139 384 4 112% 0% 3% 9% 100%

Table 49: Assessment of quantities of industrial sludge failing limit values on heavy metals (tDM).Source: calculated from WRc � SEDE, 2001

It was assumed that the fraction of industrial sludge that would have to be disposed by another routewould be disposed of by incineration. In this case, costs will be related to the costs of undertakingincineration and savings will be those made by not having to undertake land spreading.

6.286 Organic compoundsVery little information is available concerning the level of organic compounds in industrial sludge. Itseems however that their concentration should be below the limit values that would be introduced in therevised directive in all Member States. The table below presents the mean values for HAPs and PCBs,where available, and compares them to the possible new limit values and to the range of values ofEuropean urban sludge:

Sector HAP (ppm) PCB (ppm)Abattoirs 0,3 0,1Food and drink 0,1 0,1

Pulp and paper wastesludge 0,05 0,05

Leather and tannery 0,05 0,013European urban sludge 0,1 - 10 0,001 � 21Proposed limit values 500 0,8

Table 50: Comparison on mean values of organic compounds contents between European industrialsludge, European urban sludge and proposed limit values. Source: WRc � SEDE, 2001

98

6.287 Other costs (quality assurance, obligation of treatment)

Concerning the obligation of treatment, no information is available on the quantity of stabilised /unstabilised sludge. Therefore, we will use the same percentage than for urban sludge.

We assume that the unitary costs for the implementation of a quality assurance system and analyses andobligation of treatment are similar to those calculated for urban sludge.

6.29 Accession Countries

6.291 Objective

The objective of this section is to assess the costs of the application of the revised directive in the tenAccession Countries. (Estonia, Latvia, Poland, Bulgaria, Czech Republic, Hungary, Lithuania, Romania,Slovakia and Slovenia).

6.292 MethodologyThe same methodology has been applied as for Member States, with a ten-year delay, that is:

- studying the level of requirements of each Accession Country, and comparing each one with thepossible requirements of the revised directive,

- analysing the existing situation in terms of quality of sludge (heavy metals and organic compounds),quality of soils, obligation of treatment and implementation of a quality assurance system in eachAccession Country, by comparison with the possible requirements of the revised directive.

6.293 Sludge production

The forecasted quantities of sludge produced in the ten Accession Countries after implementation of theUWWT Directive, and quantities of sludge recycled, are summarised in the table below:

CountriesQuantities of

sludge produced(tDM/year)

Quantities ofsludge recycled

(tDM/year)

%recycled

Bulgaria* 138 000 42 780 31%Czech Republic 152 000 104 880 69%Estonia 23 000 4 600 20%Hungary 156 000 156 000 100%Latvia 34 000 10 880 32%Lithuania 56 000 17 920 32%Poland 571 000 0 0%Romania* 313 000 97 030 31%Slovakia 84 800 60 208 71%Slovenia 12 000 2 400 20%Total AC 1 539 800 496 698 31%

% of total AC 100% 31%

*Quantities of sludge recycled for Romania and Bulgaria have been assessed by multiplying the quantity of sludgeproduced with the average ratio (sludge recycled / sludge produced) calculated for the 8 other Accession Countries.

Table 51: Sludge production and quantities of sludge recycled in ten Accession Countries (Source:Andersen Questionnaires and ETCIW, �Implementation of the urban waste water treatment

directive in the ten Accession Countries�, scenario B or C, Final report, June 1999)

99

6.294 Specific regulationsSpecific legislation related to the production, disposal and recycling of sewage sludge is very limited inAccession Countries. Specific legislation exists in Estonia, Latvia, Poland and Slovenia (concerningheavy metals levels in sludge and heavy metals levels in soils).

- In Estonia, the national legislation provides limit values for heavy metal in sludge and soils that aresimilar to those of the directive 86/278/EC.

- In Latvia, the national legislation provides limit values for heavy metals in sludge that are similar tothose of directive 86/278/EC, and limit values for heavy metals in soils, depending on types of soils,that are similar to those that could be introduced in the revised directive. This national legislationrequires also the implementation of a soil and sludge analysis system.

- In Poland, the national legislation provides limit values for heavy metal in soils and sludge, which aresimilar to those that could be introduced in the revised directive. This national legislation requires alsothe implementation of a soil and sludge analysis system.

- The limit values set by the legislation in Slovenia for heavy metals levels in sludge as well as formaximal annual loads are more stringent than the 86 directive�s requirements. In addition, Slovenianlegislation prohibits the use of sludge on agriculture if it contains pathogens.

6.295 Sludge failing new requirements on sludge and soil

Quantities failing

Considering the lack of reliable data in Accession Countries, we assumed that the percentage of sludgefailing limit values of sludge and soil would be similar than the ones in Member States (EU 15 average).

Therefore, quantities of sludge failing (and not failing) in Accession Countries are the following ones :

No PPP scenario PPPscenarioQuantities (tDM/year)

Short term Mediumterm

Long term Worst case All limits

Quantities of sludge failing 332 787 367 556 412 259 496 698 124 175

% of sludge failing 67% 74% 83% 100% 25%

Quantities of sludge not failing 163 910 129 141 84 439 0 372 523

% of sludge not failing 33% 26% 17% 0% 75%

Table 52 : Quantities of sludge failing (and not failing) limit values in sludge and soil in AccessionCountries (tDM/year)

Unit costs

Since the lower cost of workforce and the bigger cost gap between traditional landspreading and newpractices considered in the scenarios should have opposite effects, we have considered that the unitarycosts of changing the route for sludge currently recycled in agriculture in the Accession Countries was thesame as the average costs concerning sludge of the Member States used in part 7.3.1.

100

7. Results

Results concerning urban sludge in the Member States are detailed here

Results concerning industrial sludge and Accession Countries are given separately, considering thatuncertainties are much higher than for urban sludge in Member States.

Results are detailed step by step with three tables summarising:

1. Quantities of sludge concerned by each key factor (i.e. sludge failing limit values in sludge or soil andquantities concerned by the obligation of treatment and quality assurance), expressed in ktDM/year and asa percentage of total quantities recycled,

2. Unit costs associated with each key factor, expressed in Euro/tDM,

3. Total cost obtained by multiplying each unit cost by the quantities concerned, expressed in kEuro/year.

101

7.1 Quantities (urban sludge in Member States)

Quantities of sludge concerned by each key factor 85 are detailed in the table below, expressed in ktDM/year and as a percentage of the total quantities ofsludge spread on land in the business as usual scenario:

Quantities concerned (ktDM/year) % of total quantities of sludge recycled on land86

No PPP PPP No PPP PPP

Quantities of sludge concerned

Key factor modifying cost

BAU

Shortterm

Mediumterm

Longterm

Worstcase

Alllimits

BAU

Shortterm

Mediumterm

Longterm

Worstcase

Alllimits

a Limit values on heavy metals (in sludge) 0 570 1 588 2 784 4 893 0 0% 12% 32% 57% 100% 0%

b Limit values on organic compounds (in sludge) 0 2 162 1 652 1 054 0 0 0% 44% 34% 22% 0% 0%

a + b Limit values on heavy metals and organiccompounds (in sludge),

0 2 732 3 240 3 838 4 893 0 0% 56% 66% 79% 100% 0%

c Limit values on heavy metals (in soil) 0 535 391 237 0 1 237 0% 11% 8% 5% 0% 25%

a + b+ c

Limit values in sludge and in soil 0 3 266 3 631 4 076 4 893 1 237 0% 67% 74% 83% 100% 25%

d Quality assurance system 0 1 543 1 178 775 0 3 489 0% 32% 24% 16% 0% 71%

e Obligation of treatment 0 279 221 145 0 618 0% 6% 5% 3% 0% 13%

Table 53: Quantities of sludge concerned by each key factor (ktDM/year) and percentage of the total quantities of sludge spread on land

85i.e. quantities of sludge failing limit values in sludge or soil and quantities of sludge concerned by the obligation of treatment and quality assurance86 Quantities defined in the business as usual scenario (i.e. 100% = 4.893 ktDM/year)

102

7.2 Unit costs

Unit costs (Euro/tDM) and type of sludge concerned by the change in unit cost are detailed in table below:

Type of sludge concerned by the change in unit cost

Nature of cost Type of cost Stakeholder bearingthe cost

Unitcost

(Euro /tDM)

No PPP scenario PPP scenario

Industries(removing

pollutants fromprocesses)

200Pollution prevention

cost Internal cost

Local authorities(policy) 10

NA

Sludge failing if the PPP werenot implemented :

- limit values on heavymetals in sludge

- limit values on organiccompounds in sludge

Investment andoperation costs(Internal costs)

Local authorities 154

Loss of agronomicvalue (internal

benefit)Farmers 54

External costs Citizens 40

Switch fromlandspreading to

incineration

Total cost - 248

Sludge failing:- limit values on heavy metalsin sludge

- limit values on organiccompounds in sludge

- limit values on heavy metalsin soil

Sludge failing limit valueson heavy metals in soil

Quality assurancesystem Internal cost

Water and sludgemanagement

operators15

Sludge still spread on land (i.e.not failing previous limit values)

Sludge still spread on land(i.e. not failing previous limit

values)

Obligation oftreatment Internal cost

Water and sludgemanagement

operators47

Sludge still spread on land withno sufficient treatment

Sludge still spread on landwith no sufficient treatment

Table 54: Unit costs (Euro/tDM) and type of sludge concerned by the change in unit cost

103

7.3 Total costs and benefits (urban sludge in Member States)

Replacing the type of sludge presented in table 53 by the corresponding quantities presented in table 52 (ktDM/year), we obtain the following table:

Quantities of sludge concerned by the change in unit cost (ktDM/year)

No PPP scenario PPP scenarioNature ofcost Type of cost Stakeholder

bearing the cost

Unitcost

(Euro /tDM) Short

termMediumterm

Longterm

Worstcase

Shortterm

Mediumterm

Longterm

Worstcase

Industries(removing

pollutants fromprocesses)

200

2 732 3 240 3 838 4 893Pollution

preventioncost

Internal cost

Local authorities(policy)

10

0 0 0 0

Investment andoperation costs(Internal costs)

Local authorities154

Loss of agronomicvalue (internal

benefit)Farmers

54

External costs Citizens 40

Switch fromlandspreading

toincineration

total cost - 248

3 266 3 631 4 076 4 893 1 237 1 237 1 237 1 237

Qualityinsurance

systemInternal cost Water and sludge

managementoperators

15 1 543 1 178 775 0 3 489 3 489 3 489 3 489

Obligation oftreatment

Internal cost Water and sludgemanagement

operators

47 279 221 145 0 618 618 618 618

Table 55: List of unit costs (Euro/tDM) and corresponding quantities of sludge (ktDM/year) concerned by the change in unit cost

Multiplying unit cost with the quantities of sludge concerned by the variation of unit cost detailed in previous table, we obtain total costs, as described inthe two tables hereafter for scenario n° 1 (PPP scenario) and scenario n° 2 (No PPP scenario).

104

7.31 Scenario n°1 (efficient pollution prevention policy or PPP)Total cost of scenario n°1 (PPP scenario) is detailed in table below:

SCENARIO N°1 (PPP)

Categories Costs (k�/year)

Nature of Cost Description of cost Stakeholder bearingthe cost

Unit costs(Euro/tDM)

Shortterm

Mediumterm Long term Worst case

Reduction of pollutantsloads in the sewer

Industries 200 546 217 648 076 767 692 978 523

Pollution prevention costsPolicy implementation and

controlLocal authorities 10 27 311 32 404 38 385 48 926

Investments andoperational cost (internal

cost)


154 190 444 190 444 190 444 190 444

Loss of use of sludge as afertiliser (internal benefit)

Farmer 54 66 779 66 779 66 779 66 779

Switching fromlandspreading to

incineration

External net cost Citizens 40 49 466 49 466 49 466 49 466

Quality assurance system Internal cost Water and sludgemanagement operators

15 52 333 52 333 52 333 52 333

Obligation of treatment Internal cost Water and sludgemanagement operators

47 29 050 29 050 29 050 29 050

TOTAL (in keuro/year) NA 961 599 1 068 552 1 194 148 1 415 521

Table 56: Detail of total costs of scenario n°1 (PPP), k�/year

105

7.32 Scenario n°2 (No PPP)Total cost of scenario n°2 (No PPP) is detailed in table below:

SCENARIO N°2 (No PPP)

Categories Costs (k�/year)

Nature of Cost Description of cost Stakeholder bearingthe cost

Unit costs(Euro/tDM) Short term Medium

term Long term Worst case

Reduction of pollutantsloads in the sewer

Industries 200 0 0 0 0Pollution prevention costs

Policy implementation andcontrol

Local authorities 10 0 0 0 0

Investments and operationalcost (internal cost)


154 502 968 559 194 627 655 753 463

Loss of use of sludge as afertiliser (internal benefit)

Farmer 54 176 365 196 081 220 087 264 201Switching fromlandspreading to

incineration

External net cost Citizens 40 130 641 145 245 163 027 195 705

Quality assurance system Internal cost Water and sludgemanagement operators

15 23 145 17 669 11 627 0

Obligation of treatment Internal cost Water and sludgemanagement operators

47 13 095 10 380 6 837 0

TOTAL (in kEuro/year) NA 846 215 928 568 1 029 234 1 213 369

Table 57: Detail of total costs of scenario n°2 (PPP), k�/year

106

7.4 Comparison of scenarios

7.41 Comparison of total costDifferences of total cost between the two scenarios (scenario n°2-scenario n°1) are as follows:

Total Cost (k�/year)

N° Scenario Short term Mediumterm Long term Worst case

(1) Scenario n°1 (PPP) 961 599 1 068 552 1 194 148 1 415 521

(2) Scenario n°2 (No PPP) 846 215 928 568 1 029 234 1 213 369

(1-2) Difference 115 384 139 983 164 914 202 152

(1-2) / (1) % 12% 13% 14% 14%

Table 58: Comparison of total cost of scenario, k�/year

This table shows that the difference of total costs between the two scenarios is lower than 15%, whatever thetime period is (i.e. short, medium or long term).

This limited difference is mainly explained by the relatively small difference between unit costs of pollutionprevention and unit costs of switching from landspreading to incineration (respectively 210 Euro/tDM and248 Euro/ tDM).

Considering uncertainties linked with such data, in particular those of pollution prevention (see chapter n°7.7on uncertainties and sensitivity analyses), we can consider that this difference is not significant.

107

7.42 Comparison of allocation of cost among stakeholdersThe figure below compares the allocation of costs among stakeholders between the two scenarios :

61%

21%

8%

21%

6%16%

5%

60%

3%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%No

PPP PP

P

% o

f tot

al

Citizens

Farmers

Water company

Local authority

Industry

Figure 18: allocation of costs among stakeholders (medium cost estimates, % of total, keuro/year)

While the cost of scenario n°1 is mostly borne by industries (around 60% for the medium term estimates),local authorities (20%) and water companies (8%), the cost of scenario n°2 is borne mainly by localauthorities (up to 60%, for the cost of switching from landspreading to incineration), farmers (up to 20%, forthe loss of compounds of agricultural value) and citizens (up to 16%, for environmental and health impacts).

This figure shows that the Pollution Prevention Policy scenario shifts the main part of the cost-burden fromthe local authorities, farmers and citizens to the industry.

Note: costs allocated to local authorities and water operators (costs of switching from landspreading toincineration and the costs of a quality insurance scheme) are ultimately borne by water consumers.

108

7.5 Repartition of total costs between Member States

The repartition of total costs87 between Member States is as follows:

UK26%

Denmark2%

Ireland2%

Portugal2%

France16%

Spain11%

Germany29%

Italy4%

Sweden2%

Finland2%

Netherlands2%

Greece0%

Luxembourg0%

Belgium1%

Austria1%

Figure 19: Repartition of total costs among Member States, medium cost estimate (%)

This figure shows that four Member State (Germany, UK, France, and Spain) support more than 80% of thetotal cost.

87 Total cost of medium term scenario (average of PPP and No PPP)

109

Ratio

Member States that bear the highest costs are also Member States that recycle the largest amount of sludge.

Therefore, we compared the ratio of total cost88 divided by the total production recycled on land amongMember States. Results are described in the table below:

CountriesTotal cost

(average PPP andNo PPP),

kEuro/year

Quantityrecycled,

ktDM/year

Ratio total cost /total quantity

recycled,Euro/tDM

Germany 293 252 1 391 211UK 267 621 1 118 239

France 161 108 765 211Spain 95 505 589 162Italy 40 202 189 212

Portugal 24 502 108 227Sweden 20 903 167 125Finland 20 490 115 178

Denmark 19 680 125 157Ireland 17 411 84 207

Netherlands 14 298 110 130Austria 10 728 68 158Belgium 9 522 47 203

Luxembourg 1 895 9 211Greece 1 443 7 206

Total EU 15 998 560 4 893 204

Max EU 15 293 252 1 391 239

Min EU 15 1 443 7 125

Table 59: Total costs (average of PPP and No PPP, medium scenario , kEuro/year) divided by totalquantities of sludge recycled (ktDM/year)

This table shows that the average unit cost is around 200 Euro/tDM, with variation of �40% to +20%depending on the quality of sludge in each country (countries with better sludge quality have lower unit cost).

This table confirms that total costs of scenario are almost proportional to the quantities of sludge recycled.

88 Total cost of medium term scenario (average of PPP and No PPP)

110

7.6 Weight of sludge management costs compared to overall water management costs

As sludge management cost are mainly supported by water consumers through the water bill, we estimatedthe maximum weight of sludge management costs compared to overall water management costs (watertreatment, production and delivering).

To calculate the maximum relative weight of sludge management cost, we made the following assumptions:

(1) Sludge management costs include all internal costs after dehydration (cf. part n°3 of the scope defined inchapter 4.511),

(2) The maximum internal cost of sludge management corresponds to a situation where all sludge productionis incinerated (see chapter 4.1 on unitary internal costs),

(3) 1 tDM corresponds to a water consumption of 2700 m3 (based on an average water consumption of150 l/PE/day and an average sludge production of 55 gDM/PE/day),

(4) Overall water management costs are equal to the total water service price (�full cost recovery� principle).

Following previous assumptions, the relative weight of sludge management is as follows:

Part of water cost Euro/m3

Relative weight (%of total water

management costs)

Sludge management (max) 0,12 5%

Water treatment 0,87 40%

Total water service cost 2,2 100%

Table 60 : Comparison of maximum sludge management costs with overall water management cost(average EU 15, Source: OECD, The Price of Water; Trends in OECD Countries; 1999)

This table shows that even if sludge management can involve high costs (particularly when all sludge isincinerated) these costs represent an average proportion of only 6% of the total cost water service (includingwater production, and treatment).

111

Costs are detailed for each Member State (when the information is available) in the table below:

Total waterservices cost Sludge management cost (max)

Country�/m3 �/tDM89 �/m3 90 % of total

costAustria N/A 343 0,13 N/A

Belgium 91 2,1 322 0,12 6%Denmark 3,0 339 0,13 4%Finland 2,6 319 0,12 5%France 2,9 343 0,13 4%

Germany N/A 340 0,13 N/AGreece 1,1 344 0,13 12%Ireland N/A 331 0,12 N/A

Italy 0,8 307 0,11 14%Luxembourg N/A 300 0,11 N/ANetherlands 3,0 263 0,10 3%

Portugal N/A 282 0,10 N/ASpain 1,0 296 0,11 11%

Sweden 2,4 326 0,12 5%UK (England &Wales) 2,9 311 0,12 4%

Average EU 15 2,2 318 0,12 7%Max EU 15 3,0 344 0,13 14%Min EU 15 0,8 263 0,10 3%

Table 61: Maximum costs of sludge management compared to overall water costs (Source: OECD, ThePrice of Water in 1999; Trends in OECD Countries, 1999)

Importance of sludge management costs ranges from 3% to 14 % according to the Member State. Differencesmay be explained by the fact that higher values correspond to the lower water price, corresponding to thesouthern countries of Europe, where water treatments are less developed than in Northern countries at thepresent time.

89 See chapter 4.1 on unitary internal costs90 See assumptions of previous table91 Average value of Flanders, Brussels and Wallonia

112

7.7 Sensitivity analysis

The main uncertainties and sensitivity factors are summarised in the table below:

Applicable toscenarioType of costs Sensitivity factors

PPP NoPPP

Uncertainties on the factor Relative impact onmedium scenario

Sensitivity92

Forecast of sludge production andquantities recycled

✔ ✔ +/- 20*% +/- 20*% ~100%

% of sludge not meetingrequirements

✔ ✔ +/- 50% +/- 50% ~100%

All

Discount rate ✔ ✔ +/- 50% (From 2% to 6%) +/-6% (PPP)+/- 2% (No PPP)

~10%

Pollutionprevention

Cost of evaluation ✔ Estimated to vary by afactor of 10, i.e.

from -90% to +1000%

-45% to +1000% ~50-100%

Unit cost of sludge routes✔

-30% to +50% -15% to +50% ~50-100%

Nutrients concentration in sludge(mainly N and P) (internal benefits)

✔ ✔ +/- 50% +/-10% ~20%

External costs coefficients ✔ ✔ +/- 60% +/- 9% ~20%

Switching fromlandspreading to

incineration

External cost valuation ✔ ✔ Unknown Unknown NA

Quality insurance Unit cost of quality assurance ✔ ✔ -50% to +100% -2% (No PPP)+/-5% (PPP)

~4-10%

Obligation oftreatment

Unit cost of obligation oftreatment

✔ ✔ +/-50% +/-0,5% (No PPP)+/- 1,5% (PPP)

~1%-3%

*: estimationTable 62: Sensitivity analyses of the main factors (based on the medium scenario cost evaluation)

92 Sensitivity of a factor is defined by the ratio : variation of total cost / variation of the factor (in %)

113

Costs are most sensitive to the following factors:

Forecasted quantities of sludge recycledCosts of scenarios are sensitive to the forecasts for quantities of sludge recycled, as scenario costs aredirectly proportional to the quantities of sludge recycled. A variation of the forecast quantities ofsludge recycled (for instance ±20%) would make the costs of scenario vary by the same percentage(for instance by ±20%).

Percentage of sludge not meeting proposed requirementsCosts of scenarios are very sensitive (+/- 50%) to the percentage of sludge not meeting requirements(limit values in sludge and in soil), which present also high relative uncertainties (+/- 50%).

Pollution prevention costs (PPP scenario)The estimation of the cost of a pollution prevention policy (PPP scenario) is very uncertain, due to thegeneral lack of information on pollution prevention policies. Therefore, we can estimate that costs ofthis factor can vary by a factor of ten (i.e. -90%;+1.000%), and therefore costs of the PPP scenariocan vary by almost the same range (-45%;+ 1000%).

Internal unit cost of switching from landspreading to incinerationFor the No PPP scenario, costs are relatively sensitive (-15% to +50%) to uncertainties regarding unitcost of switching from landspreading to incineration (due to assumptions on design or technologyspecificities, or on storage conditions�).

Other factorsCosts of scenarios are not very sensitive to uncertainties regarding other factors such as unit cost on qualityinsurance (less than ± 20%), nutrient concentration (internal benefits), external costs coefficients (quantifiableexternal costs), unit cost on obligation of treatment, and the discount rate (less than 6%), although there canbe high uncertainties on these type of data (higher than ± 50%).

External cost valuation method

As already mentioned earlier, uncertainties are also linked with the limits of external cost valuation: onlyairborne emission have been quantified, although other impacts (soil, water, ecosystems�) which areimpossible to assess, may have significant impacts.

114

7.8 Other results (industrial sludge and Accession Countries)

Other results concern industrial sludge and Accession Countries

As the objective is to estimate an order of magnitude of the costs involved and given that cost differencesbetween PPP and No PPP scenarios for Member States were not significant, we made estimations concerningthe No PPP scenario only.

7.81 Industrial sludgeTotal costs obtained for industrial sludge in Member States are detailed in table below (No PPP scenario):

Total cost (kEuro/year)

Type of cost Unit cost(Euro/tDM)

Shortterm

Mediumterm

Long term Worst case

Switching from landspreadingto incineration

248 0 34 199 94 984 1 019 751

Obligation of treatment 47 48 315 46 695 43 815 0

Quality insurance system 15 61 679 59 610 55 934 0

Total NA 109 993 140 504 194 732 1 019 751

Table 63: detail of total cost for industrial sludge in Member States (kEuro/year)

This table shows that total cost for industrial sludge would range between 0,1 and 0,2 billion Euro/year, with amaximum cost of 1 billion in the worst case scenario. These costs are lower than for urban sludge due tolower estimated production and better sludge quality.

UncertaintiesUncertainties linked to industrial sludge are higher than the ones for urban sludge as basic information such assludge production, quantity recycled or sludge quality is not available or reliable in every Member State.

115

7.82 Accession CountriesTotal costs obtained for Accession Countries are detailed in table below (No PPP scenario) :

Total cost (kEuro/year)

Type of cost Unit cost(Euro/tDM)

Shortterm

Mediumterm

Long term Worst case

Switching from landspreadingto incineration

248 82 531 91 154 102 240 123 181

Obligation of treatment 47 7 704 6 070 3 969 0

Quality insurance system 15 2 459 1 937 1 267 0

Total NA 92 694 99 161 107 475 123 181

Table 64: Assessment of total costs due to new requirements in Accession Countries (k�/year)

This table show that total cost for Accession Countries would range from 92 kEuro/year in the short term to107 kEuro /year in the long term. These cost are much lower than those for Member States, mainly becausethe sludge production forecast and quantities recycled are much lower than for Member States.

Uncertainties

There are very high uncertainties with respect to Accession Countries, in terms of sludge production, disposaland recycling, quality, treatments performed etc. due to the lack of accurate and reliable information.

116

7.9 Recommendations

To reduce the level of uncertainties associated with previous results and improve their overall reliability, theinformation base needs to be to improved, in particular with respect to the following aspects:

Sludge compositionA more precise evaluation of the percentage breakdown of sludge not meeting proposed requirements wouldrequire a precise and updated percentage breakdown of pollutants (heavy metals and organic compounds) inthe quantities of sludge produced and recycled for all 15 Member States.

Detailed databases with sludge quality, routes and treatmentsMore reliable results can be obtained if the database containing the details of sludge quality (percentagebreakdown) were to include the type of treatment (conventional, advanced etc) and a detailed allocation ofsludge to different disposal and recycling routes. The description of detailed categories of disposal andrecycling routes should be standardised among Member States.

Pollution Prevention Policy measures and costTo obtain more reliable results on the impact of Pollution Prevention Policy measures on the costs of scenario,more analysis is required to better define the types of measures required for such Pollution Prevention Policyin the various Member States. Also, better estimates of the costs associated to these measures are required.

Unknown external costs: human health, ecosystem degradation, etc.To make a better evaluation of external costs, it would be necessary to improve knowledge on the economicalquantification of impacts on soil biology, ecosystems, the exposure to pollutants and long-term effects onhealth (see chapter on "gaps in knowledge" in the scientific and technical report).

Industrial sludge and Accession CountriesAt the present time, even less information is available on industrial sludge and the situation in AccessionCountries than on urban sludge in Member States: for instance, basic information such as sludge quantitiesand routes are not known. Therefore more precise and reliable information should be gathered on industrialsludge and in Accession Countries in order to allow a comprehensive cost and benefits analysis.

117

8. Glossary

AC Accession CountriesADEME Agence de l�Environnement et de la Maîtrise de l�Energie (French EPA)AGHTM Association générale des hygiénistes et techniciens municipaux (French Professionnal

Organisation of municipal technicians)AOX Adsorbable Organohalogen (Organochlorine) CompoundsBAU Business as usual scenarioDEHP Di (2-ethylhexyl) phthalateDETR Department of environment, transport and regions (UK)DM Dry matterEC European CommissionEPA Environment Protection AgencyETCIW European topic center Inland WatersEU European UnionJRC Joint Research CenterLAS Linear alkyl-benzenesulphonateLCA Life Cycle AnalysisMPM Market Price MethodMS Member StatesNP NonylphenolNPE Nonylphenol ethoxylatesOECD Organisation for Economic Co-operation and Developmentp.e. population equivalentPAHs Polyaromatic hydrocarbonsPCBs Polychlorinated biphenylsPCDD Polychlorinated dibenzodioxinesPCDF Polychlorinated dibenzofuransPPP Pollution prevention policySPDE Syndicat Professionnel des Distributeurs d�Eau (French Professionnal Organisation of

Water Producers)SPM State preference methodSYPREA Syndicat professionnel du recyclage en agriculture (French Professionnal Organisation for

Recycling in Agriculture)ToR Terms of ReferenceUBA Umweltbundesamt (German and Austrian EPA)UKWIR United Kingdom Water Industry Research LtdUN United NationsUS EPA United States Environment Protection AgencyUWWD Urban Waste Water DirectiveVOC Volatile Organic CompoundsWWT Waste Water TreatmentWWTP Wastewater treatment plant

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Member States Accession countries

AT Austria BG BulgariaBE Belgium CY CyprusDE Germany EE EstoniaEI Ireland HU HungaryDK Denmark LV LatviaES Spain LT LithuaniaFI Finland MT MaltaFR France PL PolandGR Greece CZ Czech RepublicIT Italy RO RomaniaLU Luxembourg SK SlovakiaNL Netherlands SI SloveniaNO NorwayPT PortugalSE SwedenUK United Kingdom

SEWAGE SLUDGE 2/1/02 17:27 Pagina 4

Compuesta

C M Y CM MY CY CMY K

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