CEN/TR 15809:2008

SLOVENSKI STANDARD
01-maj-2009
Karakterizacija blata - Higienski vidiki - Priprava
Characterization of sludges - Hygienic aspects - Treatments
Charakterisierung von Schlämmen - Hygienische Aspekte - Schlammbehandlung
Caractérisation des boues - Aspects hygiéniques - Traitements
Ta slovenski standard je istoveten z: CEN/TR 15809:2008
ICS:
13.030.20 7HNRþLRGSDGNL%ODWR Liquid wastes. Sludge
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL REPORT
CEN/TR 15809
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
November 2008
ICS 13.030.20
English Version
Characterization of sludges - Hygienic aspects - Treatments
Caractérisation des boues - Aspects hygiéniques - Charakterisierung von Schlämmen - Hygienische Aspekte -
Traitements Schlammbehandlung
This Technical Report was approved by CEN on 25 August 2008. It has been drawn up by the Technical Committee CEN/TC 308.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 15809:2008: E
worldwide for CEN national Members.

Contents Page
Foreword.3
Introduction .4
1 Scope .5
2 Normative references .5
3 Terms and definitions .5
4 Hygienic considerations .6
4.1 General.6
4.2 From concept to good practice .6
4.3 Aspects of microbiology, virology and parasitology.7
4.4 Aspects of epidemiology .7
4.5 Definition of the hygienic objective of treatment .8
5 General methodologies and tools to define the hygienic effect of treatment, and to
manage the hygienic safety.9
5.1 General.9
5.2 Health risk assessment.10
5.2.1 Hazard identification .10
5.2.2 Dose-response assessment .10
5.2.3 Exposure assessment.10
5.2.4 Risk characterisation .10
5.3 Quality Assurance and Hazard Analysis and Critical Control Point (HACCP) for use in
sludge .11
6 Treatments available: efficiency and drawbacks .14
6.1 General.14
6.2 Biological treatment .16
6.2.1 Anaerobic digestion .16
6.2.2 Composting.16
6.2.3 Thermophilic aerobic digestion (TAD) or Aerobic thermophilic stabilisation (ATS).17
6.2.4 Long term storage .17
6.2.5 Reedbeds.17
6.3 Chemical treatment.18
6.3.1 Treatment with lime .18
6.3.2 Other chemical methods.18
6.4 Physical treatment.19
6.4.1 Pasteurisation of sludge .19
6.4.2 Thermal drying.19
6.4.3 Thermal hydrolysis.19
6.5 Combined treatment and other methods .19
Annex A (informative) Micro organisms which could be found in sewage sludge .21
Bibliography .24

Foreword
This document (CEN/TR 15809:2008) has been prepared by Technical Committee CEN/TC 308
“Characterization of sludges”, the secretariat of which is held by AFNOR.
The status of this document as CEN/TR has been chosen because much of its content is not completely in
line with the practice and regulations in each member state.
This document gives general principles about hygienic aspects. Other guides on good practice for the use of
sludge (Guides 2, 4, 5, 6, 7, 8) contain the specific recommendations based on the hygienic aspects
described in this guide.
Introduction
This Technical Report has been prepared within the framework of CEN/TC 308 on characterization of sludges.
This document concentrates on hygienic aspects for good practice concerning treatment of sludge, but
acknowledges that existing national regulations remain in force.
The use of sewage sludge on land is controlled within the EU by the sludge directive (86/278/EEC [1]) “on the
protection of the environment, and in particular of the soil, when sewage sludge is used in agriculture”.
Regarding the purpose of the directive, it states:
 whereas the aim of this Directive is to regulate the use of sewage sludge in agriculture in such a way as
to prevent harmful effects on soil, vegetation, animals and man, while encouraging its correct use;
Regarding hygiene, it requires:
 whereas sludge must be treated before being used in agriculture; whereas Member States may
nevertheless authorize, on certain conditions, the use of untreated sludge, without risk to human or
animal health, if it is injected or worked into the soil;
 whereas a certain period must elapse between using the sludge and putting stock out to pasture or
harvesting fodder crops or certain crops which are normally in direct contact with the soil and normally
consumed raw;
 whereas the use of sludge on fruit and vegetable crops during the growing season, except for fruit-tree
crops, must be prohibited.
86/278/EEC defines 'treated sludge' as:
 sludge which has undergone biological, chemical or heat treatment, long-term storage or any other
appropriate process so as significantly to reduce its fermentability and the health hazards resulting from
its use;
EU Member States have enacted the directive into their national legislations with conditions that are no less
stringent than the directive. In many cases they have more detailed treatment requirements than those written
in the directive.
The European Commission has said repeatedly that 86/278/EEC, which was the first soil protection directive,
has been a success because there have been no cases of adverse effect where it has been followed.
Sludge treatments and practices that control health risks can also affect odour; in the public’s mind they are
linked.
When making choices in sludge management the hygienic aspects should be considered alongside the
environmental impacts of the treatment such as energy use or emissions and the benefits of the final product.
1 Scope
This CEN Technical Report gives information about principles to be followed in different sludge treatment
processes to reach specified hygienic requirements.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 1085:2007, Wastewater treatment — Vocabulary
EN 12832:1999, Characterisation of sludges — Utilization and disposal of sludges — Vocabulary
CEN/TR 15473, Characterization of sludges — Good practice for sludges drying
EN ISO 22000, Food safety management systems — Requirements for any organization in the food chain
(ISO 22000:2005)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 12832:1999, EN 1085:2007 and the
following apply.
3.1
Critical Control Point (CCP)
step [in a process] at which control can be applied and is essential to prevent or eliminate a hazard or reduce
it to an acceptable level
3.2
HACCP (hazard analysis and critical control point)
system that identifies, evaluates, and controls hazards which are significant for safety
3.3
HACCP plan
document prepared in accordance with the principles of HACCP to ensure control of hazards which are
significant for safety in the segment of the chain under consideration
3.4
hazard
potential source of harm
3.5
hazard analysis
process of collecting and evaluating information on hazards and conditions leading to their presence to decide
which are significant for safety and therefore should be addressed in the HACCP plan
3.6
hygienic safety
intended degree of safety
3.7
hygienisation
process that leads to reduced levels of pathogens in order to prevent infections, and their spreading in the
exposed human, animal or plant population
3.8
monitor
act of conducting a planned sequence of observations or measurements of control parameters to assess
whether a CCP is under control
3.9
risk
combination of the probability of occurrence of harm and the severity of that harm
3.10
safety
freedom from unacceptable risk
3.11
validation
obtaining evidence that the elements of the HACCP plan are effective
3.12
verification
application of methods, procedures, tests and other evaluations, in addition to monitoring to determine
compliance with the HACCP plan
4 Hygienic considerations
4.1 General
Untreated sludge from wastewater treatment may contain different types and species of pathogens for
humans, animals and plants. The occurrence of such pathogens depends on the type and origin of the raw
materials and on the health situation with respect to the presence of diseases in the involved populations. This
does not only apply to sewage sludge, but also to wastewater, biogas residues, animal manure and other
organic fertilisers and compost of human, animal and plant origin. Environment per se is not sterile. Soil is
more than a mineral support on which plants grow, it is an ecosystem with its own indigenous flora and fauna.
Among this microflora are several potential pathogenic as well as toxigenic bacteria and fungi that can be
found in varying concentrations such as Listeria monocytogenes or Clostridium tetani. There are also
competitors and predators of the pathogens with which this guide is concerned. Hygienic considerations
include aspects of microbiology, virology, parasitology and epidemiology.
4.2 From concept to good p
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