ISO 16075-3:2015

INTERNATIONAL ISO
STANDARD 16075-3
First edition
2015-08-15
Guidelines for treated wastewater use
for irrigation projects —
Part 3:
Components of a reuse project for
irrigation
Lignes directrices pour l’utilisation des eaux usées traitées en
irrigation —
Partie 3: Éléments d’un projet de réutilisation en irrigation
Reference number
ISO 16075-3:2015(E)
©
ISO 2015

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ISO 16075-3:2015(E)

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© ISO 2015, Published in Switzerland
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ISO 16075-3:2015(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, and abbreviated terms . 1
3.1 General . 1
3.2 Use of treated wastewater (TWW) . 3
3.3 Wastewater quality . 4
3.4 Irrigation systems . 5
3.5 Wastewater system related components . 7
3.6 Abbreviated terms . 8
4 Storage reservoir . 8
4.2 Reservoir types . 8
4.3 Storage time . 9
4.4 Problems and strategies. 9
5 Additional treatment facilities .10
5.2 Filtration .10
5.3 Additional disinfection .11
6 Distribution systems .11
6.1 Pumping stations .11
6.2 Pipelines .11
6.3 Accessories .12
6.3.2 Valves .12
6.3.3 Blowoffs .13
6.3.4 Flowmeters .13
6.3.5 Hydrants .13
6.4 Resistance of irrigation material to pH and fertilizers .13
6.5 Maintenance of distribution networks to prevent bacterial regrowth .14
6.6 Design and operation of distribution network to protect drinking water sources .14
6.6.2 Stipulating a protective radius .15
6.6.3 Principles of TWW irrigation above (underground or surface) drinking
water pipelines .15
6.6.4 Principles of cross-connection .15
6.6.5 Principles of painting and marking TWW irrigation pipelines and systems .16
7 Irrigation systems .17
7.1 Classification .17
7.2 Pressurized irrigation systems .17
7.2.1 Sprinkler systems .17
7.2.2 Micro-irrigation systems .19
7.2.3 Filtration .19
7.2.4 Automation of the irrigation .20
7.3 Instructions for preventive treatments, regular maintenance, and handling
pressurized irrigation system failures subject to TWW quality .20
7.3.1 General.20
7.3.2 Water quality parameters required for the treatment and maintenance of
irrigation systems, for micro-sprinklers and drip irrigation systems .20
7.3.3 Required equipment and treatments for micro-sprinklers and drip
irrigation systems .21
7.3.4 Restoring working order of an irrigation system after failure .24
Annex A (informative) Guidelines for injecting chlorine into drip irrigation systems .25
Annex B (informative) Guidelines for acid use in drip irrigation systems .27
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ISO 16075-3:2015(E)

Annex C (informative) Guidelines for injecting hydrogen peroxide into drip irrigation systems .29
Annex D (informative) Guidelines for sampling drip irrigation pipes .34
Annex E (informative) Appropriated chemicals .36
Bibliography .38
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ISO 16075-3:2015(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 282, Water reuse, Subcommittee SC 1, Treated
wastewater use for irrigation.
ISO 16075 consists of the following parts, under the general title Guidelines for treated wastewater use
for irrigation projects:
— Part 1: The basis of a reuse project for irrigation
— Part 2: Development of the project
— Part 3: Components of a reuse project for irrigation
The following parts are under preparation:
— Part 4: Monitoring
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ISO 16075-3:2015(E)

Introduction
The increasing water scarcity and water pollution control efforts in many countries have made treated
municipal and industrial wastewater a suitable economic means of augmenting the existing water
supply, especially when compared to expensive alternatives such as desalination or the development
of new water sources involving dams and reservoirs. Water reuse makes it possible to close the water
cycle at a point closer to cities by producing “new water” from municipal wastewater and reducing
wastewater discharge to the environment.
An important new concept in water reuse is the “fit-to-purpose” approach, which entails the production
of reclaimed water quality that meets the needs of the intended end-users. In the situation of reclaimed
water for irrigation, the reclaimed water quality can induce an adaptation of the type of plant grown.
Thus, the intended water reuse applications are to govern the degree of wastewater treatment required
and inversely, the reliability of wastewater reclamation processes and operation.
Treated wastewater can be used for various non-potable purposes. The dominant applications for the
use of treated wastewater (also referred to as reclaimed water or recycled water) include agricultural
irrigation, landscape irrigation, industrial reuse, and groundwater recharge. More recent and rapidly
growing applications are for various urban uses, recreational, and environmental uses, and indirect
and direct potable reuse.
Agricultural irrigation was, is, and will likely remain the largest reuse water consumer with recognized
benefits and contribution to food security. Urban water recycling, landscape irrigation in particular,
is characterized by fast development and will play a crucial role for the sustainability of cities in the
future including energy footprint reduction, human well-being, and environmental restoration.
It is worth noting again that the suitability of treated wastewater for a given type of reuse depends
on the compatibility between the wastewater availability (volume) and water irrigation demand
throughout the year, as well as on the water quality and the specific use requirements. Water reuse
for irrigation can convey some risks for health and environment depending on the water quality, the
irrigation water application method, the soil characteristics, the climate conditions, and the agronomic
practices. Consequently, the public health and potential agronomic and environmental adverse impacts
are to be considered as priority elements in the successful development of water reuse projects for
irrigation. To prevent such potential adverse impacts, the development and application of international
guidelines for the reuse of treated wastewater is essential.
The main water quality factors that determine the suitability of treated wastewater for irrigation
are pathogen content, salinity, sodicity, specific ion toxicity, other chemical elements, and nutrients.
Local health authorities are responsible for establishing water quality threshold values depending on
authorized uses and they are also responsible for defining practices to ensure health and environmental
protection taking in account local specificities.
From an agronomic point of view, the main limitation in using treated wastewater for irrigation arises
from its quality. Treated wastewater unlike water supplied for domestic and industrial purposes
contains higher concentrations of inorganic suspended and dissolved materials (total soluble salts,
sodium, chloride, boron, and heavy metals), which can damage the soil and irrigated crops. Dissolved
salts are not removed by conventional wastewater treatment technologies and appropriate good
management, agronomic, and irrigation practices are intended to be used to avoid or minimize potential
negative impacts.
The presence of nutrients (nitrogen, phosphorus, and potassium) can become an advantage due to
possible saving in fertilizers. However, the amount of nutrients provided by treated wastewater along
the irrigation period is not necessarily synchronized with crop requirements and the availability of
nutrients depends on the chemical forms.
This guideline provides guidance for healthy, hydrological, environmental and good operation, monitoring,
and maintenance of water reuse projects for unrestricted and restricted irrigation of agricultural crops,
gardens, and landscape areas using treated wastewater. The quality of supplied treated wastewater has
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ISO 16075-3:2015(E)

to reflect the possible uses according to crop sensitivity (health-wise and agronomy-wise), water sources
(the hydrologic sensitivity of the project area), the soil, and climate conditions.
This guideline refers to factors involved in water reuse projects for irrigation regardless of size,
location, and complexity. It is applicable to intended uses of treated wastewater in a given project even
if such uses will change during the project’s lifetime as a result of changes in the project itself or in the
applicable legislation.
The key factors in assuring the health, environmental, and safety of water reuse projects in irrigation
are the following:
— meticulous monitoring of treated wastewater quality to ensure the system functions as planned
and designed;
— maintenance and design instructions of the irrigation systems to ensure their proper long-term
operation;
— compatibility between the treated wastewater quality, the distribution method, and the intended
soil and crops to ensure a viable use of the soil and undamaged crop growth;
— compatibility between the treated wastewater quality and its use to prevent or minimize possible
contamination of groundwater or surface water sources.
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INTERNATIONAL STANDARD ISO 16075-3:2015(E)
Guidelines for treated wastewater use for irrigation
projects —
Part 3:
Components of a reuse project for irrigation
1 Scope
This part of ISO 16075 covers the system’s components needed for the use of TWW for irrigation which
relate to various pressure and open irrigation systems specifically drip irrigation as this method
represents an efficient method of water delivery and water saving. Despite the fact that water quality
and filtration of treated wastewater (herein TWW) using drip irrigation are critical, open irrigation
systems are more popular and are frequently used for irrigation with TWW and therefore are covered
in this part of ISO 16075.
This part of ISO 16075 will cover the issues related to the main components of a TWW irrigation project,
including the following:
— pumping station;
— storage reservoirs;
— treatment facilities (for irrigation purposes): filtration and disinfection;
— distribution pipeline network;
— water application devices: irrigation system components and treatment.
None of the parts of this part of ISO 16075 are intended to be used for certification purposes.
2 Normative references
There are no normative references.
3 Terms, definitions, and abbreviated terms
3.1 General
3.1.1
aquifer
underground layer of water-bearing permeable rock or unconsolidated materials (gravel, sand, or silt)
from which groundwater can be extracted
3.1.2
background water
freshwater (3.1.10) supplied for domestic, institutional, commercial, and industrial use from which
wastewater (3.1.22) is created
3.1.3
barrier
any means including physical or process steps that reduces or prevents the risk of human infection by
preventing contact between the TWW and the ingested produce or other means that, for example, reduces
the concentration of microorganisms in the TWW or prevents their survival on the ingested produce
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3.1.4
environment
surroundings in which an organization (3.1.13) operates including air, water, land, natural resources,
flora, fauna, humans, and their interrelation
3.1.5
environmental aspect
element of an organization’s (3.1.13) activities, projects, or products (3.1.15) that can interact with the
environment (3.1.4)
3.1.6
environmental impact
any change to environmental quality, whether adverse or beneficial, wholly or partly resulting from an
organization’s (3.1.13) activities, projects, or products (3.1.15)
3.1.7
environmental parameter
quantifiable attribute of an environmental aspect (3.1.5)
3.1.8
fodder crops
crops not for human consumption such as pastures and forage, fiber, ornamental, seed, forest, and turf
crops
3.1.9
food crops
crops which are intended for human consumption, often further classified as to whether the food crop
is to be cooked, processed, or consumed raw
3.1.10
freshwater
naturally occurring water on the Earth’s surface (in ice, lakes, rivers, and streams) and underground as
groundwater in aquifers (3.1.1)
Note 1 to entry: Freshwater includes desalinated seawater and desalinated brackish water, but excludes seawater
and brackish water.
3.1.11
irrigation project
design, development, construction, selection of equipment, operation, and monitoring of works to
provide suitable TWW irrigation
3.1.12
non-potable water
NPW
water that is not of drinking water quality
Note 1 to entry: It generally refers to wastewater (3.1.22) or TWW, but can also include other waters of non-
drinking quality.
3.1.13
organization
group of people and facilities with an arrangement of responsibilities, authorities, and relationships
3.1.14
process
set of interrelated or interacting activities which transform inputs into outputs
Note 1 to entry: Inputs to a process are generally outputs of other processes.
Note 2 to entry: Processes in an organization (3.1.13) are generally planned and carried out under controlled
conditions to add value.
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3.1.15
product
any goods or services
Note 1 to entry: This includes interconnected and/or interrelated goods or services.
3.1.16
public health aspect
element of an organization’s (3.1.13) activities, projects, or products (3.1.15) that can interact with the
public health
3.1.17
public health impact
any change to public health, whether adverse or beneficial, wholly or partly, resulting from an
organization’s (3.1.13) activities, projects, or products (3.1.15)
3.1.18
public health parameter
quantifiable attribute of a public health aspect (3.1.16)
3.1.19
soil
layer of unconsolidated material consisting of weathered material particles, dead and living organic
matter, air space, and the soil solution (3.1.20)
3.1.20
soil solution
liquid phase of the soil (3.1.19) and its solutes
3.1.21
stakeholder
individual, group, or organization (3.1.13) that has an interest in an organization or activity
Note 1 to entry: Usually, a stakeholder can affect or is affected by the organization or the activity.
3.1.22
wastewater
wastewater collected principally by municipalities that can include spent or used water from domestic,
institutional, commercial, or industrial sources and can include storm water
3.1.23
water reuse
use of treated wastewater (3.1.22) for beneficial use
Note 1 to entry: Water reuse is synonymous to water reclamation and water recycling.
3.2 Use of treated wastewater (TWW)
3.2.1
agriculture
science or practice of farming, including cultivation of the soil (3.1.19) for the growing of crops and the
rearing of animals to provide food or other products (3.1.15)
3.2.2
landscape
all the visible features of an area of land, often considered in terms of their aesthetic appeal such as
public and private gardens, parks, road vegetation including lawns and turfed recreational areas
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3.2.3
restricted irrigation
use of TWW for non-potable applications in settings where public access is controlled or restricted by
physical or institutional barriers
3.2.4
restricted urban irrigation
irrigation of areas in which public access during irrigation can be controlled such as some golf courses,
cemeteries, and highway medians
3.2.5
unrestricted irrigation
use of TWW for non-potable applications in settings where public access is not restricted
3.2.6
unrestricted urban irrigation
irrigation of areas in which public access during irrigation is not restricted such as some gardens
and playgrounds
3.3 Wastewater quality
3.3.1
category A: very high quality TWW
raw wastewater (3.3.6) which has undergone physical and biological treatment, filtration (3.5.3) and
[1]
disinfection (3.5.2), and its quality is according to the description in ISO 16075-2 , Table 1, row A
3.3.2
category B: high quality TWW
raw wastewater (3.3.6) which has undergone physical and biological treatment, filtration (3.5.3) and
[1]
disinfection (3.5.2), and its quality is according to the description in ISO 16075-2 , Table 1, row B
3.3.3
category C: good quality TWW
raw wastewater (3.3.6) which has undergone physical and biological treatment and its quality is
[1]
according to the description in ISO 16075-2 , Table 1, row C
3.3.4
category D: medium quality TWW
raw wastewater (3.3.6) which has undergone physical and biological treatment and its quality is
[1]
according to the description in ISO 16075-2 , Table 1, row D
3.3.5
category E: extensively TWW
raw wastewater (3.3.6) which has undergone natural biological treatment process with long (minimum
[1]
10 d to 15 d) retention time and its quality is according to the description in ISO 16075-2 , Table 1, row E
3.3.6
raw wastewater
wastewater (3.1.22) which has not undergone any treatment
3.3.7
thermo-tolerant coliforms
group of bacteria whose presence in the environment (3.1.4) usually indicates faecal contamination
(previously called faecal coliforms)
Note 1 to entry: In order to determine the quality of TWW, one can test for Escherichia coli (E. coli) or for faecal
coliforms, since the difference in values is not significant.
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3.4 Irrigation systems
3.4.1
boom sprinkler
mobile sprinkling machine (3.4.11) composed by two symmetrical pipes (booms) with sprinkler nozzles
distributed in one of the pipes and the sprinkler action complemented by a gun sprinkler placed at each
end of both pipes; the nozzles work through a reaction effect (similar to a hydraulic tourniquet) which
drives the boom rotation at a desired speed
3.4.2
center-pivot and moving lateral irrigation machines
automated irrigation machine consisting of a number of self-propelled towers supporting a pipeline
rotating around a pivot point and through which water supplied at the pivot point flows radially
outward for distribution by sprayers or sprinklers (3.4.24) located along the pipeline
3.4.3
emitter
emitting pipe
dripper
device fitted to an irrigation lateral and intended to discharge water in the form of drops or continuous
flow at flow rates not exceeding 15 l/h, except during flushing
3.4.4
gravity flow irrigation systems
irrigation systems (3.4.8) where water is applied directly to the soil (3.1.19) surface and is not under
pressure
3.4.5
in-line emitter
emitter (3.4.3) intended for installation between two-lengths of pipe in an irrigation lateral
3.4.6
irrigation gun
large discharge device being either a part circle or full circle sprinkler
3.4.7
irrigation sprayer
device which discharges water in the form of fine jets or in a fan shape without rotational movement of
its parts
3.4.8
irrigation system
assembly of pipes, components, and devices installed in the field for the purpose of irrigating a
specific area
3.4.9
micro-irrigation system
system capable of delivering water drops, tiny-streams, or mini-spray to the plants
Note 1 to entry: Surface and sub-surface drip irrigation and micro-spray irrigation (3.4.10) are the main types
of this system.
3.4.10
micro-spray irrigation systems
this system is characterized by water point sources similar to sprinkler’s miniatures (micro-sprinklers)
which are placed along the laterals with a flow rate between 30 l/h and 150 l/h at pressure heads of
15 m to 25 m and the corresponding wetted area between 2 m and 6 m
3.4.11
mobile sprinkling machine
sprinkling unit which is automatically moved across the soil surface during the water application
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