SIST EN 752:2017

Drain and sewer systems outside buildings - Sewer system management

This European Standard specifies the objectives for drain and sewer systems outside buildings. It specifies the functional requirements for achieving these objectives and the principles for strategic and policy activities relating to planning, design, installation, operation, maintenance and rehabilitation.
It is applicable to drain and sewer systems from the point where wastewater leaves a building, roof drainage system, or paved area, to the point where it is discharged into a wastewater treatment plant or receiving water body.
Drains and sewers below buildings are included provided that they do not form part of the drainage system for the building.

Entwässerungssysteme außerhalb von Gebäuden - Kanalmanagement

Diese Europäische Norm legt Ziele für Entwässerungssysteme außerhalb von Gebäuden fest. Sie legt Funktionsanforderungen zum Erreichen dieser Ziele fest sowie Grundsätze für Strategie und Vorgehensweise in Bezug auf Planung, Bemessung, Bau, Betrieb, Unterhalt und Sanierung.
Sie gilt für Entwässerungssysteme von dem Punkt an, an dem das Abwasser das Gebäude bzw. die Dachentwässerung verlässt oder in einen Straßenablauf fließt, bis zu dem Punkt, an dem das Abwasser in eine Kläranlage oder ein aufnehmendes Gewässer eingeleitet wird.
Abwasserleitungen und  kanäle unterhalb von Gebäuden sind hierbei eingeschlossen, solange sie nicht Bestandteil der Gebäudeentwässerung sind.

Réseaux d'évacuation et d'assainissement à l'extérieur des bâtiments - Gestion du réseau d’assainissement

La présente Norme européenne spécifie les objectifs des réseaux d’évacuation et d’assainissement à l’extérieur des bâtiments. Elle spécifie les prescriptions fonctionnelles permettant d’atteindre ces objectifs ainsi que les principes des activités stratégiques et politiques liées à la planification, à la conception, à l’installation, à l’exploitation, à l’entretien et à la réhabilitation.
Elle s’applique aux réseaux d’évacuation et d’assainissement à partir du point où les eaux usées quittent un bâtiment, un système d’évacuation de toiture ou une surface revêtue, jusqu’au point où elles se déversent dans une station d’épuration ou un milieu récepteur aquatique.
Les branchements et collecteurs situés sous des bâtiments sont inclus, à condition qu’ils ne fassent pas partie du réseau d‘évacuation du bâtiment.

Sistemi za odvod odpadne vode in kanalizacijo zunaj zgradb - Upravljanje sistema za kanalizacijo

Ta evropski standard določa zahteve za drenažne in kanalizacijske sisteme zunaj stavb. Določa funkcionalne zahteve za dosego teh ciljev ter načela za strateške in politične dejavnosti, povezane z načrtovanjem, zasnovo, namestitvijo, delovanjem, vzdrževanjem in rehabilitacijo.
Uporablja se za drenažne in kanalizacijske sisteme, ki delujejo zlasti s pomočjo gravitacije, od točke, kjer odpadne vode zapustijo stavbo, strešni drenažni sistem ali tlakovano območje, do točke, kjer se izlivajo v čistilnih naprave za gospodinjske odplake ali sprejemajoče vodno telo.
Zajeti so tudi drenažni in kanalizacijski sistemi, ki ne tvorijo dela drenažnega sistema stavbe.

General Information

• Status: Published
• Public Enquiry End Date: 29-Oct-2015
• Publication Date: 05-Jun-2017
• ICS: 93.030 - External sewage systems
• Technical Committee: IOVO - Water supply and waste water engineering
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 05-May-2017
• Due Date: 10-Jul-2017
• Completion Date: 06-Jun-2017
• Directive: 2000/60/EC - Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy (substitutes Directive Reference 01/991 - Common Position on WFD)
• Directive: 91/271/EEC - Urban waste-water treatment
• Ref Project: EN 752:2017 - Drain and sewer systems outside buildings - Sewer system management

Relations

• Replaces: SIST EN 752:2009 - Drain and sewer systems outside buildings
• Effective Date: 01-Jul-2017
• Amended By: SIST EN 752:2017/oprA1:2025 - Drain and sewer systems outside buildings - Sewer system management
• Effective Date: 26-Feb-2025

Overview

SIST EN 752:2017 - Drain and sewer systems outside buildings - Sewer system management - is a European standard that defines objectives, functional requirements and management principles for external drainage and sewer networks. It applies from the point wastewater leaves a building, roof drainage or paved area, to discharge into a wastewater treatment plant or receiving water body. Drains and sewers under buildings are included only when they are not part of the building’s internal drainage.

This standard supports safe, sustainable and resilient sewer system performance by covering planning, design, installation, operation, maintenance and rehabilitation activities.

Key topics and technical requirements

The standard sets out structured requirements and guidance across these core areas:

• Objectives and performance goals - public health and safety, occupational health, environmental protection and sustainable development.
• Functional requirements - protection from sewer flooding, maintainability, watertightness, structural integrity, prevention of odours/toxic gases, noise control and protection of surface and groundwater.
• Performance determination - environmental, hydraulic, structural and operational performance parameters and how to define them for a network.
• Design criteria - hydraulic design for foul, surface water and combined systems; self‑cleansing conditions; outfalls; combined sewer overflow management; and structural/material selection.
• Integrated sewer system management process - systematic approach including investigation, assessment, planning, implementation and review (inventory update, hydraulic and environmental investigations, asset condition assessment, action planning, work programming and conformity measurement).
• Operational and maintenance requirements - access, inspection, preventive maintenance, rehabilitation planning and testing during construction.
• Health & safety - occupational safety considerations for sewer system work.

Practical applications and who uses it

SIST EN 752:2017 is practical for professionals responsible for the lifecycle of external sewer assets:

• Municipal utilities and water/wastewater operators - for developing sewer management plans, flood risk reduction and maintenance regimes.
• Design engineers and consultants - to set hydraulic, structural and environmental design criteria.
• Asset managers - to prioritise rehabilitation and create performance-based maintenance programs.
• Contractors and site teams - for construction, testing and verifying conformity with functional requirements.
• Regulators and environmental agencies - to assess compliance with public health and receiving-water protection objectives.

Use cases include specifying contract requirements, preparing emergency response plans, assessing combined sewer overflow solutions, and implementing sustainable energy/material choices for networks.

Related standards

SIST EN 752:2017 is intended to be used alongside other European and national standards covering wastewater treatment, pipeline materials, construction and testing, and health & safety - and is published under CEN procedures for use by national standards bodies.

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2017
1DGRPHãþD
SIST EN 752:2009
Sistemi za odvod odpadne vode in kanalizacijo zunaj zgradb - Upravljanje sistema
za kanalizacijo
Drain and sewer systems outside buildings - Sewer system management
Entwässerungssysteme außerhalb von Gebäuden - Kanalmanagement
Réseaux d'évacuation et d'assainissement à l'extérieur des bâtiments - Gestion du
réseau d’assainissement
Ta slovenski standard je istoveten z: EN 752:2017
ICS:
93.030 Zunanji sistemi za odpadno External sewage systems
vodo
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 752
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2017
EUROPÄISCHE NORM
ICS 23.040.05; 93.030 Supersedes EN 752:2008
English Version
Drain and sewer systems outside buildings - Sewer system
management
Réseaux d'évacuation et d'assainissement à l'extérieur Entwässerungssysteme außerhalb von Gebäuden -
des bâtiments - Gestion du réseau d'assainissement Kanalmanagement
This European Standard was approved by CEN on 27 February 2017.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 752:2017 E
worldwide for CEN national Members.

Contents Page
European foreword . 6
Introduction . 8
1 Scope . 10
2 Normative references . 10
3 Terms and definitions . 11
4 Objectives . 14
4.1 General . 14
4.2 Public health and safety . 15
4.3 Occupational health and safety . 15
4.4 Environmental protection . 15
4.5 Sustainable development . 16
5 Requirements . 16
5.1 Functional requirements. 16
5.1.1 Introduction . 16
5.1.2 Protection from sewer flooding . 18
5.1.3 Maintainability . 18
5.1.4 Protection of surface receiving water bodies . 18
5.1.5 Protection of groundwater . 19
5.1.6 Prevention of odours and toxic, explosive and corrosive gases . 19
5.1.7 Prevention of noise and vibration . 19
5.1.8 Structural integrity and design working life . 19
5.1.9 Watertightness . 19
5.1.10 Sustainable use of products and materials . 19
5.1.11 Sustainable use of energy . 19
5.1.12 Maintaining the flow . 19
5.1.13 Not endangering adjacent structures and utility services . 19
5.1.14 Inputs quality. 19
5.2 Determination of performance requirements for the drain and sewer system . 20
5.2.1 Introduction . 20
5.2.2 Environmental performance requirements . 22
5.2.3 Hydraulic performance requirements . 23
5.2.4 Structural requirements . 24
5.2.5 Operational requirements . 24
5.3 Design criteria . 24
5.3.1 Introduction . 24
5.3.2 Hydraulic design criteria . 25
5.3.3 Environmental design criteria . 27
5.3.4 Structural design criteria . 28
5.3.5 Operational criteria. 29
6 Integrated sewer system management . 29
6.1 Introduction . 29
6.2 Investigation . 31
6.2.1 Introduction . 31
6.2.2 Purpose of investigation . 33
6.2.3 Review of performance information . 33
6.2.4 Determine the scope of the investigation . 33
6.2.5 Review existing information . 33
6.2.6 Inventory update . 33
6.2.7 Hydraulic investigation . 34
6.2.8 Environmental investigation . 34
6.2.9 Structural investigation . 34
6.2.10 Operational investigation . 34
6.3 Assessment. 35
6.3.1 Introduction. 35
6.3.2 Assessment of the hydraulic performance . 35
6.3.3 Assessment of environmental impact . 36
6.3.4 Assess structural condition . 36
6.3.5 Assess operational performance . 36
6.3.6 Compare with performance requirements . 36
6.3.7 Identify unacceptable impacts . 36
6.3.8 Identify causes of performance deficiencies . 36
6.4 Planning . 37
6.4.1 Introduction. 37
6.4.2 Develop integrated solutions . 37
6.4.3 Assess solutions . 38
6.4.4 Prepare action plans. 39
6.5 Implementation . 43
6.5.1 Introduction. 43
6.5.2 Development of work programme . 44
6.5.3 Development of work specification . 45
6.5.4 Carrying out work. 45
6.5.5 Measuring conformity . 45
6.5.6 Review performance requirements and update plan . 45
7 Health and safety . 45
8 Design . 47
8.1 General . 47
8.2 Types of system . 48
8.3 Physical layout . 49
8.3.1 Preliminary investigations . 49
8.3.2 Layout and profile . 49
8.4 Hydraulic design . 50
8.4.1 General . 50
8.4.2 Foul drains and sewers . 50
8.4.3 Surface water drain and sewer systems . 50
8.4.4 Combined drain and sewer systems . 51
8.5 Environmental considerations . 52
8.5.1 General . 52
8.5.2 Protection of surface receiving water bodies . 53
8.5.3 Protection of groundwater . 53
8.5.4 Prevention of septicity . 53
8.5.5 Combined sewer overflows and surface water treatment . 54
8.5.6 Surface water outfalls . 55
8.5.7 Emergency overflows . 55
8.6 Structural design . 55
8.6.1 Introduction. 55
8.6.2 Structural design of pipelines . 56
8.6.3 Structural design of other components. 56
8.6.4 Materials selection. 56
8.7 Operational considerations . 57
8.7.1 General . 57
8.7.2 Control of inputs . 57
8.7.3 Self-cleansing conditions . 57
8.7.4 Access to drains and sewers . 58
9 Construction . 58
9.1 General . 58
9.2 Pipelines . 58
9.3 Ancillaries . 58
9.4 Testing . 59
10 Operation and maintenance . 59
10.1 Introduction . 59
10.2 Monitoring . 60
10.3 Data requirements . 61
10.4 Investigation and analysis of operational problems . 61
10.5 Dealing with major incidents . 62
10.6 Techniques for operation and maintenance of components. 62
11 Qualifications and training . 63
12 Sources of additional information . 63
Annex A (informative) Sources of additional information . 64
A.1 National Standards Bodies . 64
A.2 Austria . 64
A.2.1 Regulatory Bodies . 64
A.2.2 Other organizations . 64
A.3 Denmark . 64
A.3.1 Regulatory Bodies . 64
A.3.2 Other organizations . 65
A.4 Finland . 66
A.4.1 Regulatory Bodies . 66
A.4.2 Other organizations . 66
A.5 France . 66
A.5.1 Regulatory Bodies . 66
A.5.2 Other organizations . 67
A.6 Germany . 67
A.6.1 Regulatory Bodies . 67
A.6.2 Other organizations . 68
A.7 Ireland . 68
A.7.1 Regulatory Bodies . 68
A.8 Italy. 68
A.8.1 Regulatory Bodies . 68
A.8.2 Other organizations . 68
A.9 The Netherlands . 69
A.9.1 Regulatory Bodies . 69
A.9.2 Other organizations . 69
A.10 Norway . 70
A.10.1 Regulatory Bodies . 70
A.10.2 Other organizations . 70
A.11 Portugal . 70
A.11.1 Regulatory Bodies . 70
A.11.2 Other organizations . 70
A.12 Sweden. 71
A.12.1 Regulatory Bodies . 71
A.12.2 Other organizations . 71
A.13 Switzerland . 71
A.13.1 Regulatory Bodies . 71
A.13.2 Other organizations . 72
A.14 United Kingdom . 72
A.14.1 Regulatory Bodies . 72
A.14.2 Other organizations . 74
Annex B (informative) Rehabilitation approaches . 75
Annex C (informative) Operation and maintenance techniques . 77
C.1 Pipelines . 77
C.1.1 General . 77
C.1.2 Functional problems . 77
C.1.3 Structural problems. 77
C.2 Manholes and inspection chambers . 78
C.3 Combined sewer overflows . 78
C.4 Detention tanks . 79
C.5 Separators, settling chambers and gullies . 79
C.6 Pumping installations . 79
C.7 Inverted siphons . 79
C.8 Pest control . 80
C.9 Making connections to existing drains and sewers . 80
C.10 Control of disused drains and sewers . 80
C.11 Control of building over or adjacent to sewers . 80
Annex D (normative) Physical layout of the system . 82
D.1 Preliminary investigations . 82
D.1.1 General . 82
D.1.2 Topography . 82
D.1.3 Geotechnical survey . 82
D.1.4 Groundwater . 83
D.1.5 Existing drainage services . 83
D.1.6 Other existing utility services . 83
D.2 Layout and profile . 83
D.2.1 Introduction. 83
D.2.2 Layout . 83
D.2.3 Accessibility . 84
D.2.4 Depth . 85
D.2.5 Need for pumping . 85
D.2.6 Pumping installations . 86
D.2.7 Drains and sewers near water abstraction areas . 86
D.3 Access to drains and sewers . 86
Bibliography . 88

European foreword
This document (EN 752:2017) 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 October 2017, and conflicting national standards shall
be withdrawn at the latest by October 2017.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
This document supersedes EN 752:2008.
The principal changes in this revision are as follows:
a) the terminology has been aligned with EN 16323:2014;
b) all the text relating to the determination of performance requirements and design criteria has been
moved to Clause 5 as these are essentially part of this policy activity and not the design process;
c) Clause 5 has been updated to include references to show the links to the EU Water Framework
Directive (2000/60/EC) together with its daughter directives and the EU Floods Directive
(2007/60/EC);
d) Clause 6 has been updated to align with the latest revision of EN 13508-1 and some text that is
duplicated in EN 13508-1 has been deleted;
e) Clause 6 has been updated to align with EN 14654-2;
f) contingency and emergency planning has been moved from the former Annex C to Clause 6 as it is
part of the integrated sewer system planning process;
g) some additional text from the former Annex D has been added to Clause 7, this has allowed the
former Annex D to be deleted as it largely duplicated Clause 7;
h) additional requirements have been added to Clause 8 on resilience of drain and sewer systems;
i) all physical design requirements in the former Clause 9 have been moved to a new Annex D;
j) all the hydraulic design requirements in the former Clause 9 have been moved to prEN 16933-2 to
provide a more coherent narrative;
k) former Clause 11 (now Clause 10) has been updated to include requirements on dealing with major
incidents;
l) the text of the former Clause 12 has been integrated into 6.5.5, 10.4 (now 9.4) or 11.2 (now 10.2) as
appropriate;
m) the text from the former Annex A has been incorporated either in Clause 5 or Clause 7;
n) a new Annex B on rehabilitation approaches has been added;
o) the text from the former Annex C has been incorporated into Clause 6 (for planning activities),
Clause 11 or the new Annex C;
p) the former Annex F has been deleted as this is superseded by the prEN 16932 series.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Introduction
Drain and sewer systems are part of the overall wastewater system that provides a service to the
community. This can be briefly described as:
— removal of wastewater from premises for public health and hygienic reasons;
— prevention of flooding in urbanized areas;
— protection of the environment.
The overall wastewater system has four successive functions:
— collection;
— transport;
— treatment;
— discharge.
Wastewater can, if necessary after treatment, be discharged to the environment or reused.
Collection and transport of wastewater is provided by drain and sewer systems.
Drain and sewer systems were installed because there was a need to remove the polluted water to
prevent diseases.
Traditionally, drain and sewer systems were constructed to collect and transport all types of
wastewater together irrespective of the initial source. This led to difficulties in handling the peak flows
in times of heavy rainfall and to the introduction of combined sewer overflows, which discharged
polluted water to surface receiving water bodies.
It was later recognized that separate systems, where foul wastewater was kept separate from runoff
derived from surface water, would be an improvement over such combined systems.
Although many drain and sewer systems started out as combined systems there are strong arguments
for considering the separation of foul wastewater and surface water. The pollutant effects are not the
same and the separation of effluents allows for the different treatment for each element of wastewater,
providing more environmentally friendly solutions.
This concept is included in the approach of integrated sewer management.
This European Standard provides a framework for the design, construction, maintenance operation and
rehabilitation of drain and sewer systems outside buildings. This is illustrated in the upper part of the
diagram in Figure 1. This European Standard is supported by more detailed standards for the
investigation, design, construction, organization and control of drain and sewer systems.
Investigation and assessment standards include:
— EN 13508 (all parts), Investigation and assessment of drain and sewer systems outside buildings.
Design and construction standards include:
— prEN 16932 (all parts), Drain and sewer systems outside buildings — Pumping systems,
— prEN 16933-2, Drain and sewer systems outside buildings — Design — Part 2: Hydraulic design,
— EN 1295 (all parts), Structural design of buried pipelines under various conditions of loading,
— EN 1610, Construction and testing of drains and sewers,
— EN 12889, Trenchless construction and testing of drains and sewers,
— EN 15885, Classification and characteristics of techniques for renovation and repair of drains and
sewers.
Management and control standards include:
— EN 14654 (all parts), Management and control of operational activities in drain and sewer systems
outside buildings.
To support these detailed standards information comes from specifications produced by individual
organizations for their own use. Product standards should also take into account the functional
requirements in this European Standard through EN 476, EN 13380 and EN 14457.

Figure 1 — Pyramid diagram
The EU Public Procurement Directive (2014/25/EU) governs the procurement of goods and services by
public authorities. This includes procurement in relation to drain and sewer systems.
The Construction Products Regulation (No 305/2011) provides for uniform assessment methods of the
performance of construction products which are set out in harmonized European Standards.
1 Scope
This European Standard specifies the objectives for drain and sewer systems outside buildings. It
specifies the functional requirements for achieving these objectives and the principles for strategic and
policy activities relating to planning, design, installation, operation, maintenance and rehabilitation.
It is applicable to drain and sewer systems from the point where wastewater leaves a building, roof
drainage system, or paved area, to the point where it is discharged into a wastewater treatment plant or
receiving water body.
Drains and sewers below buildings are included provided that they do not form part of the drainage
system for the building.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. 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
EN 858-1, Separator systems for light liquids (e.g. oil and petrol) — Part 1: Principles of product design,
performance and testing, marking and quality control
EN 858-2, Separator systems for light liquids (e.g. oil and petrol) — Part 2: Selection of nominal size,
installation, operation and maintenance
EN 1295-1, Structural design of buried pipelines under various conditions of loading — Part 1: General
requirements
EN 1610, Construction and testing of drains and sewers
EN 1825-1, Grease separators — Part 1: Principles of design, performance and testing, marking and
quality control
EN 1825-2, Grease separators — Part 2: Selection of nominal size, installation, operation and
maintenance
EN 1990:2002, Eurocode — Basis of structural design
EN 12889, Trenchless construction and testing of drains and sewers
EN 13508-1, Investigation and assessment of drain and sewer systems outside buildings — Part 1: General
Requirements
EN 14654-1, Management and control of operational activities in drain and sewer systems outside
buildings — Part 1: Cleaning
EN 16323:2014, Glossary of wastewater engineering terms
prEN 16932 (all parts), Drain and sewer systems outside buildings — Pumping systems
prEN 16933-2, Drain and sewer systems outside buildings — Design — Part 2: Hydraulic design
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 16323:2014 and the following
apply.
Note 1 to entry: Certain key definitions from EN 16323:2014 have been repeated below for clarity. The
following additional terms used in this European Standard are defined in EN 16323:2014:
aerobic, anaerobic, backdrop manhole,
biochemical oxygen demand, catchment area, collection tank,
combined sewer overflow, combined system, confined space,
dam board, detention tank, domestic wastewater,
drain, dry weather flow, exfiltration,
extraneous flow, foul wastewater, gradient,
gravity system, hydro-biological stress, industrial wastewater,
infiltration (see Figure 2), inspection chamber, inverted syphon,
jetting, maintenance, manhole,
non-domestic wastewater outfall, pumping station,
ramp manhole, receiving water body, rehabilitation,
relevant authority, renovation, repair, replacement,
retention period, rising main, rodding,
runoff coefficient, self-cleansing, self-purifying capacity,
separate system, septic wastewater, sewer, sewer system,
surcharge, tank sewer, time of concentration,
time of flow, wastewater, wastewater treatment plant,
winching.
3.1
backwater level
elevation of the surface of the wastewater predicted or occurring in a drain and sewer system due to the
hydraulic conditions downstream
3.2
design working life
assumed period for which a structure or part of it is to be used for its intended purpose with anticipated
repair and maintenance but without renovation or replacement being necessary
...