ISO 20419:2018

INTERNATIONAL ISO
STANDARD 20419
First edition
2018-10
Treated wastewater reuse for
irrigation — Guidelines for the
adaptation of irrigation systems and
practices to treated wastewater
Réutilisation des eaux usées traitées en irrigation — Lignes
directrices pour l’adaptation des systèmes et pratiques d’irrigation
aux eaux usées traitées
Reference number
©
ISO 2018
© ISO 2018
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Published in Switzerland
ii © ISO 2018 – All rights reserved

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Treated wastewater (TWW) . 2
3.2 Filtration . 2
4 TWW quality monitoring for micro-irrigation . 4
4.1 General . 4
4.2 TWW quality monitoring devices . 4
4.2.1 Flushing counter for automated filters . 4
4.2.2 pH level sensor . 4
4.2.3 Clogging capacity meter . 4
4.2.4 Chlorine demand sensor . 5
4.3 TWW quality monitoring procedure . 5
5 TWW reservoirs . 5
5.1 General . 5
5.2 TWW reservoir safety . 5
5.3 TWW reservoir design . 5
5.4 Type of TWW stored in the reservoir . 5
5.5 Quality of TWW stored in the reservoir . 6
5.6 Reservoir processes affecting TWW quality and derived reservoir operation . 6
5.7 Reservoir engineering data and design . 6
5.8 Biological treatment in reservoirs . 6
6 Filtration systems . 7
6.1 General . 7
6.2 Filtration battery manifold structure . 8
6.3 Filtration technology — Filtration media .12
6.4 Flow/filter area ratio .12
6.5 Filtration stations location in accordance with flow direction .12
6.6 Filtration grade .13
6.7 Manual filter cleaning .13
7 Pumping stations .13
7.1 General .13
7.1.1 Bottom pumping chamber .13
7.1.2 Floating suction head .13
7.2 Reservoir stratification prevention .14
8 Adaptation of emitters to TWW .15
8.1 General .15
8.2 Emitters classification .15
8.3 Drippers .15
8.3.1 General.15
8.3.2 On-surface dripper and sub-surface dripper .15
8.4 Durability and longevity of dripper .15
8.5 Functional features of the dripper .15
8.5.1 General.15
8.5.2 Functional features .16
8.6 Sprinkler/centre pivot/frontal pivot .20
8.6.1 General.20
8.6.2 Overhead sprinkler .20
8.6.3 Mini sprinklers .21
8.6.4 Micro sprinklers and sprayers .21
8.6.5 Center pivot sprinklers/sprayers .22
9 Design parameters for TWW irrigation.22
9.1 General .22
9.2 Design parameters for TWW irrigation systems (drippers, sprinkler irrigation
machines) .22
10 Physical treatment .23
10.1 General .23
10.2 Flushing mains, sub-mains and tubes .23
10.3 Collector pipes .23
11 Chemical treatment .24
Annex A (informative) Definition of TWW quality and treatment recommendations for
micro-sprinkler irrigation or drip irrigation .25
Annex B (informative) TWW quality parameters and test methods .26
Annex C (informative) pH effect on Chlorine concentration .27
Annex D (informative) Clogging capacity meter .29
Annex E (informative) Sprinklers spacing according to wind conditions .33
Annex F (informative) Water stratification in reservoirs .34
Annex G (informative) Reservoir inspection and maintenance specification .36
Annex H (informative) Chemical treatments in a reservoir .38
Annex I (informative) Application of filtration systems to protect drip irrigation systems
and spraying systems using TWW: the Israeli experience .39
Bibliography .41
iv © ISO 2018 – All rights reserved

Foreword
ISO (the International Organization for Sta
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