EN 12255-10:2023

SLOVENSKI STANDARD
01-maj-2023
Nadomešča:
SIST EN 12255-10:2001
Čistilne naprave za odpadno vodo - 10. del: Varnostna načela
Wastewater treatment plants - Part 10: Safety principles
Kläranlagen - Teil 10: Sicherheitstechnische Baugrundsätze
Stations d’épuration - Partie 10 : Principes de sécurité
Ta slovenski standard je istoveten z: EN 12255-10:2023
ICS:
13.060.30 Odpadna voda Sewage water
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 12255-10
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2023
EUROPÄISCHE NORM
ICS 13.060.30 Supersedes EN 12255-10:2000
English Version
Wastewater treatment plants - Part 10: Safety principles
Stations d'épuration - Partie 10 : Principes de sécurité Kläranlagen - Teil 10: Sicherheitstechnische
Baugrundsätze
This European Standard was approved by CEN on 6 February 2023.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12255-10:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Symbols and abbreviations . 6
5 Requirements . 6
5.1 General . 6
5.2 Confined spaces . 7
5.3 Hazardous substances . 8
5.4 Warning systems for the safety of persons . 8
5.5 Open water . 8
5.6 Vehicular and pedestrian traffic routes . 9
5.6.1 Access considerations . 9
5.6.2 Operational considerations . 9
5.6.3 Passageways. 10
5.6.4 Steps and ramps. 10
5.7 Fixed ladders, manhole steps and staircases . 10
5.8 Manholes and manways . 10
5.9 Falling preventions and covers . 11
5.10 Emergency exits . 11
5.11 Work places, work platforms and maintenance platforms . 12
5.12 Lifting equipment . 12
5.13 Electrical installations . 12
5.14 Ventilation . 12
5.15 Areas at risk from explosions . 13
5.16 Hygienic facilities . 13
5.17 General warning signs . 14
6 Special requirements . 15
6.1 Systems for separating solids from wastewater . 15
6.2 Wastewater pumping stations . 15
6.3 Aeration tanks . 16
6.4 Digestion tanks, low-pressure gasholders . 16
6.5 Digester gas pipes . 16
6.6 Desulphurizing plants . 17
6.7 Gas engine rooms and gas engines . 17
6.8 Gas flares . 18
6.9 Sludge dewatering . 18
6.10 Installations for storage and handling of chemicals and hazardous substances . 18
Annex A (informative) Relevant standards containing safety requirements . 19
Annex B (informative) Relevant EC Directives that contain safety requirements . 22
Bibliography . 24
European foreword
This document (EN 12255-10:2023) has been prepared by Technical Committee CEN/TC 165 “Waste
water engineering”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by September 2023, and conflicting national standards
shall be withdrawn at the latest by September 2023.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 12255-10:2000.
This is the tenth part prepared by Working Group CEN/TC 165/WG 40 relating to the general
requirements and processes for treatment plants for a total number of inhabitants and population
equivalents (PT) over 50.
The EN 12255 series, Wastewater treatment plants, consists of the following parts:
— Part 1: General construction principles
— Part 2: Storm management systems
— Part 3: Preliminary treatment
— Part 4: Primary treatment
— Part 5: Lagooning processes
— Part 6: Activated sludge process
— Part 7: Biological fixed-film reactors
— Part 8: Sludge treatment and storage
— Part 9: Odour control and ventilation
— Part 10: Safety principles
— Part 11: General data required
— Part 12: Control and automation
— Part 13: Chemical treatment — Treatment of wastewater by precipitation/flocculation
— Part 14: Disinfection
— Part 15: Measurement of the oxygen transfer in clean water in aeration tanks of activated sludge
plants
— Part 16: Physical (mechanical) filtration
NOTE Part 2 is under preparation.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Introduction
Differences in wastewater treatment throughout Europe have led to a variety of systems being
developed. This document gives fundamental information about the systems; this document has not
attempted to specify all available systems. A generic arrangement of wastewater treatment plants is
illustrated below in Figure 1:

Key
1 preliminary treatment
2 primary treatment
3 secondary treatment
4 tertiary treatment
5 additional treatment (e.g. disinfection or removal of micropollutants)
6 sludge treatment
7 lagoons (as an alternative)
A raw wastewater
B effluent for re-use (e.g. irrigation)
C discharged effluent
D screenings and grit
E primary sludge
F secondary sludge
G tertiary sludge
H stabilized sludge
I digester gas
J returned water from dewatering
Figure 1 — Schematic diagram of wastewater treatment plants
The primary application is for wastewater treatment plants designed for the treatment of domestic and
municipal wastewater.
NOTE For requirements on pumping installations at wastewater treatment plants see EN 752, Drain and
sewer systems outside buildings and the EN 16932 series, Drain and sewer systems outside buildings — Pumping
systems:
— Part 1: General requirements;
— Part 2: Positive pressure systems;
— Part 3: Vacuum systems.
1 Scope
This document defines minimum safety requirements to be observed in the planning, construction or
reconstruction of wastewater treatment plants.
The purpose of this document is to ensure the protection of people.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 476, General requirements for components used in drains and sewers
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— IEC Electropedia: available at https://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
confined space
space in which the ventilation is restricted to the extent that special safety precautions need to be taken
[SOURCE: EN 16323:2014, term number 2.1.3.4]
3.2
manway
tightly lockable access opening in containers, tanks, vessels, boilers, bunkers etc. through which a
person can enter to perform inspection or repair work
4 Symbols and abbreviations
ATEX Explosive Atmospheres (ATEX) Directives (2014/34/EU and 1999/92/EC)
LEL lower explosive limit
5 Requirements
5.1 General
Compliance with safety regulations is an integral part of the design and construction of the facilities.
National or local regulations can exceed the requirements laid down in this document. In those
jurisdictio
...