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1

JUNE 2023
Reuse of Treated Wastewater in
Urban/Peri-Urban Agriculture in India 2

Reuse of Treated Wastewater in Urban/Peri-Urban Agriculture in India
Publisher
NATIONAL INSTITUTION FOR TRANSFORMING INDIA (NITI) AAYOG, NEW DELHI
This document is prepared by Water & Land Resources vertical, NITI Aayog, Govt. of
India.

Authors:
Avinash Mishra, Adviser
Arunlal K., Associate
Dr. Shikha Anand, Young Professional
Dr. Snigdha Goel, Young Professional

Disclaimer
This document is intended as Reuse of treated wastewater in urban/peri-urban
agriculture in India. While every effort has been made to ensure the correctness of
data/information used in this report, NITI Aayog does not accept any legal liability for
the accuracy or inferences drawn from the material contained therein or for any
consequences arising from the use of this material. NITI Aayog does not claim
copyright for any images produced in the report. No part of this report may be
reproduced in any form (electronic or mechanical) without prior permission from or
intimation to NITI Aayog.

The report should be referenced as follows:
Avinash Mishra, Arunlal K., Dr. Shikha Anand, Dr. Snigdha Goel. 2023. Reuse of
treated wastewater in urban/peri-urban agriculture in India, NITI Aayog, Govt. of India,
New Delhi.

Text from this can be quoted provided the source is acknowledged.

Contact
NITI Aayog
NITI Aayog Bhawan
Parliament Street, New Delhi -
110001
India
Website: www.niti.gov.in
Write to us: amishra-pc@gov.in i

Preface
As the country steadfastly progresses to a multi-trillion dollar economy, water is the
one of the key resources which can catalyze the growth. On the other hand, the very same
resource – water – can hinder the growth if it is not managed judiciously. One of the least
addressed aspects, despite being the most challenging, is the productive reuse of treated
wastewater. Generation of wastewater is common to places where there is plenty of water, and
where it is scarce. The impact of unmanaged wastewater is manifold as it pollutes freshwater
sources in water plenty zones while it raises water security concerns in arid regions. However,
it is a fact there are hardly any incentives or motivation to treat and reuse wastewater for
productive purposes. As Hon’ble Prime Minister has urged in the State Water Ministers’
conference, a vision on water is an important dimension of the journey of Amrit Kaal. Water
Vision will not be complete unless the wastewater is given the due importance it deserves. It is
in this context, NITI Aayog has decided to shed light on reuse of treated wastewater for
productive purposes. Agriculture being the largest user of freshwater, it will be the most
appropriate sector where treated wastewater could be impactful; and the urban and peri-urban
areas are important because of the availability of wastewater.
This document highlights the scope of reuse of treated wastewater for urban/peri-
urban agriculture, its challenges and the way forward. The potential of reusable treated
wastewater keeps on increasing as the urban centers grow out to accommodate the fast pace
of urbanization. Moreover, the Nitrogen and Phosphorous contained in treated wastewater
gives it an advantage over the raw freshwater, while using for agriculture. It is heartening to
observe that many States have been coming forward with specific policy for reuse of treated
wastewater. This publication is expected to augment the ongoing efforts, and encourage
interested stakeholders in making effective reuse of the valuable resource. Today, we have
GIS tools and satellite images to make the planning easier and quicker. We have also
presented a few examples in this direction.
I am thankful to Prof. Ramesh Chand, Hon’ble Member, NITI Aayog for his much
valuable guidance, suggestions and directional inputs. Support and motivation by Shri. B.V.R.
Subrahmanyam, CEO, NITI Aayog is deeply acknowledged. I appreciate my team members in
NITI Aayog for their sincere efforts. Mr. Arunlal K., Associate has made remarkable contribution
through wide research reflecting the technical know-how, and coordinating the works with
other team members. Dr. Shikha Anand and Dr. Snigdha Goel, Young Professionals were
instrumental throughout the preparation of this document, and have demonstrated their niche
skills by providing significant inputs. I am also grateful to many who have helped me and team
directly and indirectly.
I am confident that this document will trigger a new paradigm of thinking and
practicing making the maximum out of treated wastewater.

AVINASH MISHRA ii

Contents

Preface ............................................................................................................................... i
Introduction ................................................................................................................... - 1 -
Water availability and demand .................................................................................... - 2 -
Wastewater generation ................................................................................................ - 4 -
Challenges in managing waste water ......................................................................... - 4 -
Reuse of treated wastewater ....................................................................................... - 7 -
Reuse of treated wastewater in urban/peri-urban agriculture ................................. - 8 -
Examples of reuse of treated wastewater in agriculture ........................................ - 10 -
Policies, Standards and Regulations ....................................................................... - 13 -
Way forward ............................................................................................................... - 16 -
Conclusion .................................................................................................................. - 25 -
References ................................................................................................................. - 26 -
Appendix ......................................................................................................................... 27

iii

This page has been kept blank
- 1 -

Introduction
As the nation progresses at a fast pace to achieve its development objectives,
and strives to be a multi-trillion dollar economy in short span of time, the resources will
be consumed at an equally vigorous rate. For leap-frogging in any sector, water is the
first and foremost requirement amongst all the natural resources. Water has its
footprint associated with all products right from the inception, throughout the life cycle
and even after its useful life. Unlike other raw materials or resources, water is an
integral element in all sectors of the economy with certain variations in the extent and
way of utilization. The National Commission for Integrated Water Resources
Development (NCIWRD) estimated India’s water demand at a range of 973 to 1180
billion cubic metre (BCM) for the year 2050, while the utilizable fresh water remains
pegged at around 1140 BCM. The commission, while submitting the report in 1999,
has highlighted the importance of reducing water requirement to low demand
scenario.
In India three major areas of fresh water use, in the order of volume of usage,
are agriculture, domestic, and industry. The undesirable commonality among all types
of use is the fact that water once used becomes “waste” and is being “thrown/flowed
/flushed out” of the system. Agriculture sector bears the blame of diverting the single
largest share of close to 90% of fresh water supplied at a significantly low efficiency
less than 40%. However, besides the runoff from the fertilizer/pesticide mixed farms, a
significant share of the water supplied for irrigating the farm land is still fit and
available for uses, either as surface water in near-by water courses or in sub-surface
water storages or as ground water. The major Indian industries are also water-
conscious and most of them are meticulous in recycling and reusing, partly because of
process efficiency and partly due to the wide acceptability of green-marketing. But the
Indian urban centres that are growing at an annual rate of 2.38% (average during the
period 2010-2021), and consuming about 28 BCM of water annually, discharges 80%
of the fresh water supplied in used/waste/non-reusable forms. As per the estimates of
Central Pollution Control Board (CPCB), based on population for the year 2020 and
taking sewage generated per person per day as 148 litres (i.e. 80% of per capita water - 2 -

supply at a rate of 185 litres per day), Indian urban centers generate sewage of 72368
million litres per day (MLD) which works out to be 26.41 BCM annually.
Water availability and demand
Every year on an average, India receives nearly 4000 BCM of water through
rainfall, of which about 1999 BCM forms available water resources in rivers, lakes,
reservoir, ground water and glaciers. However, the distribution of this quantity is not
uniform across the country; apparently some river basins are acutely drought prone,
while some are frequently devastated by flood. For example, the most flood prone
basin of Brahmaputra & Barak, have an annual average water availability of 614 BCM,
drains its major share into Bay of Bengal. At the same time, basins like Cauvery and
East Flowing Rivers (EFR) between Pennar and Kanyakumari are facing water
deficiency (Avinash Mishra and Arunlal K., 2022). On the other hand, India’s
development requirements grow at an optimistically positive rate. Population growth is
also not an exception. The UN’s population projection for India by 2050, which was
relied upon by the NCIWRD while assessing the water demand for 2050, was 1500
million. But, we are about to cross this figure in 2030 itself. In addition, there is a
surge in migration to urban centres leading substantial growth in urban water demand.

Figure 1: Projection of Indian Urban Population till 2050
Source: World Bank’s DataBank
https://databank.worldbank.org/source/population-estimates-and-projections#
487.7
543.78
608.15
676.85
747.32
816.4
882.7
0
100
200
300
400
500
600
700
800
900
1000
2015 2020 2025 2030 2035 2040 2045 2050 2055
India's Urban Population Projection
(in million) - 3 -

Studies show that urbanizing countries are rapidly converging to those diets which
raise concerns such as greater use of land, water, and energy resources, greenhouse
gas emissions, inequitable access to healthy food, and food security. Based on these
trends and linkages, impending urbanization and associated dietary changes pose
significant human health and environmental sustainability challenges (Pandey, B.,
2020). Estimates suggest that percentage of urban population will grow from the
current 35% to 36% to about 52% to 53% by 2050.

Figure 2: Projected percentage of urban population in India
Source: World Bank’s DataBank
https://databank.worldbank.org/source/population-estimates-and-projections#

This indicates that the rise in urban population is not just because of the overall
population growth, but contributed by migration to urban centres as well. Evidently,
there will be a proportionate increase in water consumption by urban centres.
Sometimes, urbanization comes at the cost of extinction of water bodies, shrinking of
wet lands and disturbance of water balance. This often leads to long-hauling of fresh
water from rural fresh water sources and subsequent conveyance losses.
37.38
40.14
43.17
46.37
49.60
52.84
20.00
25.00
30.00
35.00
40.00
45.00
50.00
55.00
2025 2030 2035 2040 2045 2050
% Urban population - 4 -

Wastewater generation
The population projection data suggests that the wastewater generation will
increase by about 75% to 80% in the next 25 years, which by volume works out to be
50000 MLD to 55000 MLD , and thus taking the total estimated wastewater
generation to 1.3 lakh MLD. At this rate, about 0.8 BCM of wastewater will be
generated additionally every year, and thus the total annual wastewater volume is
expected to reach close to 48 BCM by 2050. This volume is about 3.5 times the
existing installed treatment capacity, which testifies the necessity of scaling up of
treatment capacity, robust system for wastewater collection, and a well-accepted
framework for reusing the treated wastewater (TWW).
Table 1: Estimated wastewater generation till 2050
Year Projected urban
population
(in million)
Estimated
wastewater
generation* (MLD)
Annually
generated
quantity (BCM)
2025 543.78 80479.44 29.37
2030 608.15 90006.2 32.85
2035 676.85 100173.8 36.56
2040 747.32 110603.36 40.37
2045 816.4 120827.2 44.10
2050 882.7 130639.6 47.68
*Estimated @ 145 lpcd (i.e. 80% of 185 lpcd fresh water supplied)

Challenges in managing waste water
Managing wastewater is quite challenging in India on account of variety of
reasons including mixing up of all kinds of used water, lack of sewage networks, issues
related to improper/lack of maintenance, giving less importance than it deserves, and
misconception on abundance on freshwater availability and many more. However, two
most important challenges are the significant gap in existing treatment capacity, and
the less penetration of advanced treatment technology.
Gap in treatment capacity
Owing to the gap in treatment capacity, only one third of this sewage load, i.e.
26869 MLD, is being treated, which works out to be 9.81 BCM annually. This scenario - 5 -

is going to aggravate as the water demand grows. Moreover, the treatment capacity is
not growing in the same pace as that of urbanization, and there is significant gap
between installed capacity and actual utilization. According to the United Nation’s
report, on average, high-income countries treat about 70% of the municipal and
industrial wastewater they generate. That ratio drops to 38% in upper middle-income
countries and to 28% in lower middle-income countries. In low-income countries, only
8% undergoes treatment of any kind. (UN WWD, 2017).
As of 2020, the country has 1469 STPs with total installed capacity of 31841
MLD. Further there are 162 STPs proposed with a capacity of 4827 MLD, which would
bring the total installed capacity to 36668 MLD. Thus, we can treat volume of about
13.38 BCM annually, while the projected wastewater generation is 47.67 BCM as
shown in Table 1. While analysing the treatment capacity between 2014 and 2020 it
is seen that there is a growth of about 50% in the six-year period. Installed capacity
grew from 22648 MLD at 2014 to 31841 MLD by 2020, that is an addition of 1532
MLD every year. But, to cope with the projected demand of 130639 MLD by 2050,
annual growth rate should be 3132 MLD, which is double the existing pace.
The capital cost required to address the gap in the treatment capacity is
justifiable. The benefits to society of managing human waste are considerable, for
public health as well as for the environment. For every USD 1 spent on sanitation, the
estimated return to society is USD 5.5 (UN WWD, 2017). The gap existing in the
treatment capacity is the biggest challenge in effectively managing the wastewater.
The un-treated water finds its way to freshwater sources or aquifer and thus adding
stress to freshwater availability. It is also pertinent that even the installed capacity is
not fully utilised. Out of the operational capacity of 26869 MLD actual utilization is
20235 MLD, and only capacity of 12200 MLD is complying with the consented norms
prescribed by the SPCBs/PCCs (CPCB, 2021). In addition to this, lack of sewer
network, issues in connectivity, problems associated with handling peak loads and
improper maintenance affect efficacy of sewage collection.
Treatment technology
Next important parameter is the treatment technology used in STPs. Sequential
Batch Reactor (SBR) and Activated Sludge Process (ASP) are the prevalent and
adopted technologies all across the country. Various treatment technologies used in - 6 -

India are tabulated in Table 2 and list of commonly used technologies across the globe
and its potential usability for irrigation are mentioned in Table 3.

Table 2: Technologies used in the sewage treatments plants (STPs) in India
Technology Technology type Number Capacity
(in MLD)
Activated Sludge Process (ASP) Conventional 321 9,486
Sequencing Batch Reactors (SBR) Conventional 490 10,638
Extended Aeration (EA) Advanced 30 474
Fluidized Aerobic Bed Reactor (FAB) Advanced 21 242
Moving Bed Biofilm Reactor (MBBR) Advanced 201 2,032
Upflow Anaerobic Sludge Blanket (UASB) Advanced 76 3,562
Oxidation Pond (OP) Natural 61 460
Waste Stabilization Pond (WSP) Natural 67 789
Others (Aerated Lagoon (AL), Trickling Filter (TF), Bio-Tower,
Electro Coagulation (EC) etc.)
364 8,497
Data Source: National Inventory of Sewage Treatment Plants, CPCB

Table 3: Commonly used technologies and its potential usability for irrigation (Jean-
Martin, 2022)
Technology Restrictive uses
(Fruit trees, industrial
crops, cooked food crops)
Non-Restrictive use
Aerated lagoons Fit Requires disinfection
Single stage constructed
wetlands
Fit Not fit
Constructed wetlands hybrid Fit Not fit
Extended Aeration:
Sequencing Batch Reactor
Fit Requires disinfection
(Filtration and disinfection
for reuse by drip irrigation)
Trickling Filter (TF) Fit Requires disinfection
Rotating Bio-Contractor Fit Requires disinfection
UASB Followed by Waste
stabilization pond
Fit for reuse Fit
Due to high algae
production, use through
drip irrigation requires
filtration to remove the
suspended solids.
UASB Followed by TF Fit Not fit
Disinfection with UV Fit Fit - 7 -

Disinfection with Chlorine Fit Fit
Rotary Disc Filter Fit Requires disinfection
Fluidized Aerobic Bed Reactor
(FAB)
Fit Requires disinfection
Moving Bed Biofilm Reactor
(MBBR)
Fit Requires disinfection
Phytorid Technology
6
Fit Fit
UV photocatalysts
7
Fit Fit

Reuse of treated wastewater
The treated wastewater (TWW), in almost entirety, is either discharged to the
watercourses or being used for irrigating parks, lawns or public places. Its reuse for
non-potable purposes, such as crop irrigation, industrial processes, and groundwater
recharge, is still relatively uncommon. Only a small fraction of treated wastewater finds
its way back into productive use, representing an untapped resource that could
alleviate water scarcity concerns. As inferred from the inventory of STPs published by
CPCB, just less than 1000 MLD, which is about 3% of treated wastewater and 1% of
wastewater generated, is being reused for some valuable purposes. Non-utilization of
TWW is wastage of resource, capital cost of treatment facility, and the expense
incurred in treating the used water.
Safe Reuse of Treated Wastewater (SRTW) is beneficial on multiple grounds.
Firstly, on the water quality front, it curbs the issue of soil degradation and
groundwater contamination. Secondly, it reduces human health hazards while dealing
with contaminated water and consuming food items grown from untreated water.
Thirdly, it could replace or supplement groundwater or surface water (or freshwater)
irrigation and help to curb alarming issues such as the over-extraction of groundwater
(NITI Aayog, 2022). While considering the options for reuse of TWW for valuable
purposes, peri-urban agriculture stands first for various reasons. As cities continue to
grow and consume more water, there is added pressure on elements for agricultural
production such as water, land, energy. In parallel, climate change impacts are
affecting the availability and distribution of water resources due to extreme floods and
droughts. This implies urgent need to wisely use the water resources we have for
productive purposes. - 8 -

Reuse of treated wastewater in urban/peri-urban agriculture
FAO defines urban and peri-urban agriculture (UPA) as practices that yield food
and other outputs through agricultural production and related processes
(transformation, distribution, marketing, recycling etc), taking place on land and other
spaces within cities and surrounding regions. It involves urban and peri-urban actors,
communities, methods, places, policies, institutions, systems, ecologies and
economies, largely using and regenerating local resources to meet changing needs of
local populations while serving multiple goals and functions. UPA offers a fundamental
strategy for building the resilience of a city’s food supply.
Use of TWW for irrigation in farm fields in the proximity of treatment plants,
which was otherwise being irrigated from a much farther water source, can reduce
distribution losses. Further, the TWW could be clubbed with micro irrigation methods
for horticulture crops. Thus, the actual saving on fresh water will be much more than
the quantity of TUW used for irrigation.
There are varying estimates on the irrigation potential of treated wastewater
from 6 ha per MLD to 90 ha per MLD as listed in Table 4
Table 4: Estimates on area that could be irrigated per unit of treated wastewater
Area per MLD Source Remarks/Assumptions
6 ha
Adapted from Winrock International
India; Institute for Studies and
Transformations; Jadavpur
University. Department of
Economics; Eco Friends; Spatial
Decisions; Youth for Unity and
Voluntary Action (YUVA), 2006.
Direct irrigation
39 ha
Indirect irrigation after mixing
with freshwater sources
45 ha FAO 8000 cum per ha
6.4 to 19.2 ha
Authors’ estimate
80 to 200
ha/MCM
40% efficiency
240 days irrigation
90 to 40 ha
Micro irrigation
4000 to 9000 cum per ha
(depending on crops)

According to FAO, 368 million ha of land are actually irrigated globally
(AQUASTAT, 2020). Approximately 317 km³ of municipal wastewater generated every
year could potentially irrigate close to 40 million hectares (with approx. 8,000 m³ per
hectare), or 10% of all irrigated lands. The low percentage of wastewater that is being - 9 -

used by agriculture in a planned manner – and its unsafe application in most cases –
confirms the vast potential for improving and increasing the application of used water
(from municipal, industrial and agricultural sources) to meet the water demand for
global food production. (UN WWD, 2017). In Indian context, the irrigated area is close
to 100 million ha and the annual wastewater generation is about 29 km
3
which can
irrigate 3.6 million ha. Considering a cost of INR 4 lakh per ha, the development cost
per hectare of culturable command area in surface minor irrigation projects, it would
cost INR 1.44 lakh crore (USD 18 billion) to create an irrigation potential of this extent.
Water erosion and other land degradation issues have depleted nutrients from
the soil, thus reducing its quality. A majority of the states have soils deficient in macro
nutrients such as NPK (nitrogen, phosphorous, potassium) and essential micro
nutrients such as zinc. This causes crop yields to suffer and necessitates higher
artificial fertiliser use (McKinsey, 2013). Nutrient rich treated wastewater can be
carefully used to address this issue to some extent and thus offset chemical fertiliser
use to a certain degree. Typical estimate of estimate ranges of nitrogen, phosphorus
and organic carbon potentially contained in municipal wastewater globally is presented
in Table 5.
Table 5: Typical composition of raw municipal wastewater of different strengths
(Mateo-Sagasta and et.al., 2015)
Contaminants/resources Unit
Concentration
Weak Medium Strong
Nitrogen (total as N) mg/L 20 40 85
Phosphorus (total as P) mg/L 4 8 15
Total organic carbon (TOC) mg/L 80 160 290
Quantity of Nitrogen and Phosphorus contained in the wastewater generated in
India in a year is given in Table 6. Consumption, Production and Import of Nitrogen and
Phosphorus is presented in Table 7.
Table 6: Quantity of N&P contained in wastewater generated at present and projected
in 2025 (in Lakh Tonnes)
Year
Component Weak Medium Strong
2021 Nitrogen (total as N) 5.28 10.56 22.45
Phosphorus (total as P) 1.06 2.11 3.96
2030 (Projected) Nitrogen (total as N) 6.57 13.14 27.92
Phosphorus (total as P) 1.31 2.63 4.93 - 10 -

Table 7: Consumption, Production and Import of N & P (in Lakh Tonnes)
Year 2018-19 2019-20 2020-21 Average
Category N P N P N P N P
Consumption 179 69 191 77 204 90 191 78
Production 133 46 137 48 137 47 136 47
Import 47 32 52 24 56 25 52 27
Even for a weaker concentration sewage, the N and P contained is 10% and 4%
of the import quantity respectively.
Examples of reuse of treated wastewater in agriculture
There are many countries which have included treated wastewater reuse as an
important dimension of water resource planning, using high-cost technology for urban
areas (such as activated sludge, membrane reactor) and low-cost ones for the rural
areas (natural lagoon, constructed wetland etc.), taking into consideration the eco-
friendly vision.
Reuse of treated waste water in Morocco (Adapted from UNESCO, 2020)
Morocco, a country known for its rapid population growth, urbanization and
increasing economic growth, is suffering from water deficit and pressure on water
resources. Water management is the key issue for Morocco as the country regularly
faces extreme environmental events. In 2016, a sudden severe drought negatively
impacted agricultural activity and production, during which the country’s GDP
decreased by 3.3%. According to the FAO, 83% of agricultural lands are not irrigated in
Morocco, which is a percentage that needs to be reduced in the future. In addition, the
country is suffering from significant variations in rainfall and droughts. One of the best
alternatives to deal with this problem is treated wastewater reuse especially in
agriculture. Forty-five percent (45%) of the total quantity of wastewater issued from
wastewater treatment plants (WWTP) is now reused for agriculture in Morocco, which
is a volume of 80 Mm
3
and could irrigate 4,000 hectares in 2020. The national water
strategy (NWS), adopted by the Moroccan government in 2010, considers treated
wastewater to have great potential in terms of facing water scarcity and facing the
increasing demand for water, food and energy (UNESCO, 2020)
In 2004, only 8% of wastewater was treated, the rest was discharged directly into the
sea (52%), the surface freshwater system (32%) and septic systems, causing serious - 11 -

pollution of the coastline, rivers and groundwater. This wastewater treatment rate was
increased in 2012 to 28%. By 2009, over 100 WWTPs are installed, mainly in small
and medium size towns in the interior of the Moroccan country.
The economic gain generated by the reuse of treated wastewater compared to
irrigation with conventional water is reported to be very positive and attractive. This
gain is due to the supply of treated water as an alternative water resource and to the
nutrients provided by these waters. A 100 mm clean water slide (1,000 m3/ha) would
provide crops with a fertigation equivalent of 40 kg of mineral nitrogen/ha, 11 kg of
assimilable phosphorus/ha and 28 kg potassium/ha.

The Mas Pijoan Ranch, Spain (Adapted from Mateo-Sagasta, J. and et.al, 2010)
The Mas Pijoan Farm uses 0.137 Mm3/yr of reclaimed water. The farm is
located in Solius, a community belonging to Santa Cristina d’Aro municipality. The farm
has 300 cattle on 150 ha, 40 ha of which are irrigated for barley, rye, oats and corn for
fodder. Until 2003, the farm irrigated 35 ha from the local aquifer. The yield of wells at
the beginning of the summer could reach 150 m
3
/h, but would decrease during the
season to 20m
3
/h, thus water could not be guaranteed at crucial crop growing stages.
Competition for water in the area was always high. Managers of the nearby golf
courses shifted in 1998 to the use of reclaimed water due to recurrent shortages in
their groundwater supplies and the prohibition on the use of groundwater for irrigation.
The Mas Pijoan Farm found that connecting to the reclaimed water pipeline of the
Costa Brava Golf Course was a reasonable solution. The Golf Course irrigation is in
operation from 9 pm to 7 am, and the water is supplied to agriculture during the rest
of the day. The agreement between the golf course and the farmer includes the
operation of a reversible pumping station to ensure that the golf course can be
supplied from the storage pond of Mas Pijoan using well water if necessary. The
arrangement has provided mutual reliability and flexibility to both users. The cost of
connecting the existing pipeline to the storage pond was 70% funded by the European
Agricultural Fund for Rural Development (EAFRD). Total private investment was 80,000
€. The farmer signed a 25-year service contract to share the use and associated
operation and maintenance cost of the reclaimed water pipeline from the Golf course.
Between 2003 and 2006 this arrangement enabled the farmer to increase total
irrigated land from 35 ha to 41.6 ha, due to the reliability of the reclaimed water, - 12 -

amounting to 136,000 m
3
/yr in 2006, or 65% of his water needs. The balance of
water used by the farm is drawn from groundwater supplies. Overall, the ranch is
irrigated partly with reclaimed water, partly with well water and partly with a mixture of
the two.

There are examples within India, though in a relatively small scale, which reuse
the treated wastewater for agriculture purposes.

Delhi
In 2016, New Delhi Municipal Council started promoting decentralised STPs to deal
with the wastewater load in the city and promote recycling of used water for
horticulture and irrigation. To supplement drinking water demand, Delhi Jal Board
supplies around 89 MGD treated effluent for no drinking purposes i.e. irrigation,
Horticulture, cooling of Power Plants and Industrial use etc. (Tyagi, 2022)

Chandigarh
Chandigarh is fully covered with sewerage facility and provided with the 100%
sewerage treatment facility. As per 2020 estimates, utilizable treatment capacity of
the city is 25% more than the quantity of sewage generated. Recognizing the
importance of water, Chandigarh had, earlier in 1991, initiated tertiary treatment of
wastewater at Diggian STP (45 MLD) and later supplied it for the non-potable uses
such as irrigation of gardens, green belts & lawns, washing cars etc., to different
sectors. Presently, the installed capacity for tertiary treatment is 90 MLD at Diggian
STP which is treating 45 MLD water on average.
The Tertiary Treated (TT) Water SCADA project is being implemented to monitor the
quantity and quality of recycled water to save the precious water resources being used
for irrigation purposes in the city. Presently, the TT Water is being supplied to all the
sectors without any automatic monitoring resulting in the non-equitable distribution of
TT Water. The proposed SCADA system will include monitoring of BOD, COD, TSS, pH,
DO, residual chlorine, as well as flow measurement, pressure measurement, etc. by
installing various analyzing equipment and sensors (NIUA, 2023). - 13 -

Policies, Standards and Regulations
In the absence of specific standards and guidelines, the wastewater reuse for
irrigation is practiced informally in India. Local governments and industries in several
parts of the country earn income by selling treated or untreated wastewater to local
farmers. However, a lack of comprehensive standards and policy framework is
hindering the development of a formal market, appropriate technology and sustainable
business/financial models (Mahreen, 2022). Some states have already formulated
policies on reuse of treated wastewater.
West Bengal has a policy titled “Treated wastewater re-use policy of urban West
Bengal” published on June 2020. The policy highlights need of sustainable
management of water resources by way of establishing an effective system of re-use of
treated wastewater by the urban citizens of West Bengal thereby reducing dependency
on fresh ground/surface water resources, and bringing reforms in the areas of
Planning, Institution, Finance, Technology and Legal & Regulation. Advantage and
need of reusing treated wastewater in agriculture is accepted in the document.
Gujarat’s “Policy for reuse of treated wastewater” (May, 2018) envisions to maximise
the collection and treatment of sewage generated and sustainable reuse of treated
water thereby reducing dependency on freshwater sources. The policy puts forward an
ambitious target of reuse of 70% of treated wastewater by 2025, and 100% reuse by
2030.
In December 2017, Karnataka approved “Policy for urban wastewater reuse” with a
goal to establish an enabling environment for the reuse of municipal wastewater to
maximize efficient resource use, protect the environment, address water scarcity and
enhance economic output. Agriculture is one of the major categories of reuse in this
policy. Pricing of water and operational cost recovery of wastewater treatment plant
are also outlined.
Chhattisgarh’s Urban Administration and Development Department has come up with
Wastewater Recycle and Reuse policy with the objective of promoting reuse of treated
wastewater with stipulated quality for non-drinking purpose. The document envisions
that water reuse is for co-existence of domestic, agriculture and industrial sectors and - 14 -

for the growth of state to avoid any conflict with each other for precious water
resources.
Jharkhand Wastewater Policy, 2017 considers wastewater as a perennial water source
recognizes it as an integral part of renewable water resources. Policy urges that urban
local bodies shall develop and manage wastewater systems, its treatment and reuse.
However, there is cautious approach towards the reuse for agricultural purposes owing
to the lack of wide social acceptance and apprehension of health risks.
The Department of Urban Development & Housing, Madhya Pradesh has prepared
“Govt. of M.P. State Level Policy (2017) for Waste Water Recycle & Faecal Sludge
Management (FSM)” to accomplish the objectives of ‘The National Urban Sanitation
Policy 2008’ and ‘Atal Mission for Rejuvenation and Urban Transformation Scheme’.
Though the policy identifies agriculture as one of the potential areas for reuse, it limits
the use in public parks, golf courses, urban green belts, freeway medians, cemeteries,
and residential lawns citing that agriculture land is hardly available in urban area.
Andhra Pradesh’s policy on wastewater reuse and recycle for urban local bodies
encourages to substitute groundwater with treated wastewater. It also prioritizes use
of reclaimed water for industry and agriculture as much as possible in order to save
the fresh water for domestic uses. Policy also outlines institutional arrangements,
participatory approach and legislative measures in this regard.
In 2016, Rajasthan’s Local Self Government Department published State Sewerage
and Wastewater Policy to ensure improved health status of urban population,
especially the poor and under privileged, through the provision of sustainable
sanitation services and protection of environment. As per the policy, treatment of
wastewater shall be targeted towards producing an effluent fit for reuse in irrigation in
accordance with WHO guidelines as a minimum requirement. Possible financial
models and approach for incentivization are also included.
Haryana notified policy on reuse of treated wastewater in October 2019 keeping in
view the limited availability of water resources in the State and also issues relating to
quality of water. The priority of reuse in the decreasing order is Thermal Power Plants,
Industrial Units, Construction Activities, Dual water supply system in
houses/offices/business establishments, large commercial use, municipal use, and
agriculture/irrigation. Policy specifies “TWW shall be used for agriculture/irrigation - 15 -

purposes provided surplus quantity is available after meeting the demands of the
above-mentioned uses.”
Punjab has notified Treated Wastewater Policy in 2017 which prioritizes agricultural
reuse of treated effluent for unrestricted irrigation. Policy states that crops to be
irrigated with treated effluent or blend thereof with freshwater resources shall selected
to suit the irrigation water, soil type and chemistry, and the economics of the reuse
operations.

Figure 3: States having policy on reuse of treated water

Maharashtra’s State Water Policy encourages recycling or reuse of treated wastewater
and mandates penal action of the polluter of water resources. The policy considers
that at least 80% of the water used for domestic purpose will be available for reuse. - 16 -

Therefore, it is the obligation of local bodies to make available, entire quantity of
generated sewage, for reuse after treating it to the standards prescribed by the
Maharashtra Pollution Control Board (MPCB). There is no separate policy for
wastewater reuse.
Tamil Nadu has policy to reuse treated waste water for industrial and agriculture uses.
Memorandum of Understanding (MoUs) are signed between Urban Local Bodies and
user agency for reuse of secondary treated effluent water. Jammu and Kashmir’s
“State Policy for Wastewater Reuse” was formulated in 2017 (before formation of UT
of Ladakh and UT of J&K). Uttar Pradesh also has a draft policy on reuse of treated
waste water.
National framework on reuse of treated waste water
National Mission for Clean Ganga (NMCG) has come up with a National Framework for
Safe Reuse of Treated Wastewater, in November 2022, in consultation with NITI Aayog
and various other organizations as part of India-European Union water partnership.
The framework envisions that a sustainable circular economy approach is required for
widespread and safe reuse of treated water to reduce pressure on surface water
resources, pollution on the environment and risk of public health. It presents a brief
information about existing polices and standards, and a model framework for State
SRTW policy.
Way forward
Demand creation is the paramount in ensuring sustainability of reuse of treated
wastewater. When the freshwater is almost free, it is very difficult to sell the treated
wastewater at a price. There should be clearly visible and convincing advantages for
using the TWW, or there should be a reasonable pricing for the freshwater. While the
latter option may not be quite easy to implement, the former option could be tried out
in select and specific areas where there is no bounty of free freshwater. Treated
wastewater could be used in three ways.
1. Direct supply to the farm fields through pipes or existing channels
2. Discharge to a pond or surface body which is used as an irrigation source
3. Managed aquifer recharge - 17 -

The indirect uses have certain disadvantages such as threat of polluting freshwater
sources, repetitive consumption of energy consumed in pumping water from aquifer
storage, non-quantifiable benefits etc. Moreover, it does not add to the productive use
of treated wastewater. So, there should be some sort of incentivization for urban/peri-
urban farmers to encourage the use of treated wastewater. The reuse of treated
wastewater in agriculture may not be seen as a revenue recovery system, rather the
primary agenda should be the effective utilization of the investments already made for
treatment infrastructure, and operation and maintenance. However, the industries
operating and drawing freshwater from the same hydrological unit may be asked to
compensate the financial gap arising out of supplying treated wastewater to
urban/peri-urban agriculture.
Economic feasibility of treated wastewater use could only be assessed from a broader
perspective at river basin level or watershed level; it cannot be confined to a single
sector such as agriculture. An integrated approach of water resource management
(IWRM) that considers all water-related issues and their interdependencies, as far as
possible, is required. (Mateo-Sagasta, J. and et.al., 2010).
Use of GIS tools in planning - 18 -

Since each State/UT and each STPs location has unique advantages and limitations,
the re-use strategy should be formulated to suit the local conditions. Site specific
planning is essential to harness the full potential and to device customized strategies
to address challenges. This could be done with the help of freely available and user
friendly GIS tools to identify the potential farm fields around an STP which could be
irrigated using the treated wastewater. On a conservative scale, an extent of 6 ha per
MLD could be used for planning (the least value form Table 4: Estimates on area that
could be irrigated per unit of treated wastewater). This will help to identify if there are
potential scope of reuse of TWW in agriculture; distance to the prospective farm fields;
need and extent of distribution infrastructure; extent of farm fields; proximity with
market centres; further scope of expansion etc.

Figure 4 Google Earth image showing STP in Haryana and farm fields in its proximity - 19 -

Figure 5 Google Earth image showing STP in Telangana and farm fields at a distance,
at downstream of nearby river

Figure 6 Information palette of STP and farm fields at distance of about 2 km - 20 -

Figure 7: 27 MLD capacity STP in Uttarakhand, and prospective area at 1.5 km
proximity

Figure 8: 45.7 MLD capacity STP in Tamil Nadu with potential irrigable area of 274.2
ha

- 21 -

Figure 9: 345 MLD capacity in Uttar Pradesh with potential to irrigation 2070 ha area

Figure 10: STP and potential area of reuse in Daman and Diu & Dadra and Nagar
Haveli - 22 -

Present fresh water irrigated area need not be converted to treated wastewater
irrigation, while exploring the scope of reuse of TWW. The area deprived of irrigation
should be the first priority to irrigate using treated wastewater, then the areas not
having sufficient water for irrigation.
Use in conjunction with drip irrigation method is suitable since drip irrigation limits the
direct contact with TWW as it is directly taken to the root zone area through pipe
networks, and thereby reduces health risks to farmers to a great extent. This could be
combined with precision farming/fertigation methods where farmer can customize the
fertilizer to suit the characteristics of output water quality from the treatment plants.
The following points require attention while using the treated wastewater for irrigation:
i. Wastewater has relatively high sodium adsorption ratio (SAR) in comparison
with fresh water. High SAR of irrigation water could have adverse impacts on
crops and soil.
ii. Wastewater irrigation could lead to temporal and long-term salinization due to
its salts (cations and anions) content. This can also cause an adverse impact
on soil structure.
iii. Return water from farm fields: Since the quality of treated wastewater is
dependent on the source of the water, type of usage and the treatment
technology, the treated wastewater may still contain some pollutants or
contaminants. This has the potential of polluting surface/ground water
sources while flowing back from the farm fields.
iv. Risk of pathogen exposure: There are possibilities of pathogen being present
even after treatment of waste water, if disinfection or advanced filtration
treatment such as membranes are not part of the treatment system.
v. Bio accumulation: Heavy metals present in the waste water can accumulate in
the environment and enter the food chain. Even at the low concentration
levels, long term irrigation can pose risk for environment and human health.
vi. Weeds and mosquito: A rise in weeds is observed in fields using wastewater
for agriculture, thereby, increasing the amount of pesticide applied. This can
be reduced by using drip irrigation. Also, the practice of storing the wastewater - 23 -

before applying to the fields creates breeding grounds for the disease carrying
mosquitoes.
The presently treated wastewater, if reused for urban/peri-urban agriculture, is
sufficient to irrigate a minimum extent of 1.23 lakh ha taking into account all losses,
while it can go up to 9.25 lakh ha and beyond if distributed and used efficiently.
Table 8: States generating more than 1000 MLD and approximate irrigation potential
State
Sewage
Load (MLD)
Treated quantity
(MLD)
Irrigation potential (ha)
@ 6 ha/MLD @ 45 ha/MLD
Andhra Pradesh 2882 309 (11%) 1854 13905
Gujarat 5013 2687 (54%) 16122 120915
Haryana 1816 1284 (71%) 7704 57780
Jharkhand 1510 15 (1%) 90 675
Karnataka 4458 2712 (60%) 16272 122040
Kerala 4256 47 (1%) 282 2115
Madhya Pradesh 3646 536 (15%) 3216 24120
Maharashtra 9107 4242 (47%) 25452 190890
NCT Delhi 3330 2412 (72%) 14472 108540
Odisha 1282 50 (4%) 300 2250
Punjab 1889 1360 (72%) 8160 61200
Rajasthan 3185 478 (15%) 2868 21510
Tamil Nadu 6421 995 (15%) 5970 44775
Telangana 2660 706 (27%) 4236 31770
Uttar Pradesh 8263 2510 (30%) 15060 112950
West Bengal 5457 213 (4%) 1278 9585
Total 123336 925020
Data Source: CPCB, 2021

Standards for reuse of treated wastewater
The essential step in implementing reuse of treated wastewater in agriculture is
the formulation of standards. According to the International Organization for
Standardization (ISO), the important concept in water reuse is the “fit-for-purpose”
approach, which entails the production of reclaimed water quality that meets the
needs of the intended end-users. The ISO has published guidelines for treated
wastewater use for irrigation projects which 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. ISO 16075:2020 specifies
guidelines for treated wastewater use for irrigation projects intended to prevent public - 24 -

health risks within the population that has been in direct or indirect contact with the
TWW or with any product that has come in contact with the TWW.
In order to expand the group of crops for irrigation purposes that can be
irrigated with the different qualities of TWW, the concept of creating “barriers” has
been developed. The barriers are methods to minimize the possibility of pathogens
passing from the TWW to the vegetables or ingestion by the consumers. Irrigation
barriers may be used to prevent contact between pathogens in TWW and humans who
ingest irrigated food crops or may inhale aerosols produced during irrigation.
The barriers should include the following:
a. disinfection of the TWW;
b. appropriate physical separation of the TWW and the vegetables or the fruits;
c. installation of a physical barrier (such as a sun-resistant cover sheet) between
the TWW and the fruit;
d. use of subsurface drip irrigation so that contaminated water does not ascend
to the ground surface by capillary action;
e. irrigation under the foliage when the fruit is at an appropriate distance from
the TWW.
f. cessation of irrigation ahead of harvesting to allow pathogen die-off.
The characteristics of crops that can be considered as preventing the pathogens from
being ingested by the consumer should include the following:
a. fruit with an inedible skin (such as citrus fruits, banana, and nuts);
b. crops that are always cooked before consumption (such as potatoes);
c. fruit and cereals undergoing a very high-heat treatment prior to ingestion
(such as wheat).
Relevant tables from ISO 16075:2020 depicting categories of treated wastewater
quality according to chemical, physical and biological parameters, and the specified
barriers are given in Appendix-A.
A set of proposed set of actions and timelines is presented in Table 9.
Table 9: Timeline and actions for implementation
Timelines Steps/actions
Immediate
(Within 2 months)
Finalization of standards in consultation with CPCB
Testing of effluent water quality of all STPs - 25 -

Identification of non-complying STPs
Short-term
(Within 6 months)
Retrofitting/modernization of non-complying STPs
Identification of STPs where urban/peri-urban agriculture is
present/feasible within 10 km
Formation/revival of beneficiary associations
Estimation, feasibility analysis and site selection
Implementation and monitoring groups comprising of CPCB,
Agriculture Dept, Irrigation Dept., Health Dept, FSSAI, and ULBs.
Mid-term
(Within 1 year)
Land acquisition wherever necessary
Laying of pipelines/construction of leading channels form STPs
to farms
Establishing micro-irrigation infrastructure
Long-term/ continuous TWW quality monitoring (bi-weekly/monthly)
Health monitoring of farmers, farmworkers and surrounding
population
Quality testing of agriculture produce
Sharing of monitoring reports with the implementation and
monitoring groups

Conclusion
There is a wide consensus on the need, necessity and advantages of reusing the
treated wastewater for productive purposes. Many States have devised policies in this
direction with a vision on encouraging the reuse of treated wastewater. Though all
policies are not quite encouraging about reuse of treated wastewater in agriculture,
there is no blanket ban either. The significant addition of treatment capacity in the
country and the growth of urbanisation underlines the importance of reuse of treated
wastewater in urban/peri-urban agriculture. However, there needs to be a concerted
effort to overcome the social stigma associated with this. This could be achieved only
through forming quality standards for reuse of treated wastewater specific to the
purpose it is meant for. Further to this, there should be a monitoring mechanism to
ensure the quality of treated wastewater, and the quality of agricultural produce
harvested from the crops irrigated using it. There could be provisions for third-party
testing as well. The plans for reuse of TWW need to be tailor-made for each of the STPs
with the help of GIS tools, wide consultation and clearly chalked-out plan for operation
and maintenance. Treated wastewater is a wealth that none can ignore in the coming
decade where water becomes scarce and the needs increase manifold.

- 26 -

References
1) Avinash Mishra and Arunlal K., Equitable Water Resources Management,
Kurukshetra, Vol. 70, July 2022, pg. 5 to 9.
2) Brault, Jean-Martin, Konrad Buchauer, and Martin Gambrill. 2022. “Wastewater
Treatment and Reuse: A Guide to Help Small Towns Select Appropriate
Options.” World Bank, Washington, DC.
3) CPCB (Central Pollution Control Board) 2021, National Inventory of Sewage
Treatment Plants (STPs), Ministry of Environment, Forest and Climate Change,
Government of India.
4) Mahreen Matto, Wastewater a resource: Plugging water supply and demand
gap, Elets g-gov, September 2022, Vol. 18, Issue 10, pg. 44 to 26.
5) Mateo-Sagasta, J. and Burke, J. 2010. Agriculture and Water Quality
Interactions: A Global Overview. SOLAW Background Thematic Report-TR08.
Rome, Food and Agricultural Organization of the United Nations (FAO).
6) Mateo-Sagasta, J., Raschid-Sally, L. and Thebo, A. 2015. Global wastewater and
sludge production, treatment and use. P. Drechsel, M. Qadir and D. Wichelns,
Wastewater: Economic Asset in Urbanizing World. Springer Netherlands.
7) McKinsey, 2013, India as an agriculture and high value food powerhouse: A
new vision for 2030, Food and Agriculture Integrated Development Action 3.
8) National Institute of Urban Affairs (NIUA), 2023, Case Study A22, Case Studies
of Innovative Projects of Smart Cities Mission: Part-A Urban Management.
9) NITI Aayog, 2022, Urban Wastewater Scenario in India, Govt. of India
10) Pandey, B., Reba, M., Joshi, P.K. et al. Urbanization and food consumption in
India. Sci Rep 10, 17241 (2020).
11) R.S. Tyagi, Water use efficiency: Steps taken by Delhi Jal Board, Elets g-gov,
November 2022, Vol. 18, Issue 12, pg. 24 to 26.
12) UNESCO and UNESCO i-WSSM. 2020. Water Reuse within a Circular Economy
Context (Series II). Global Water Security Issues (GWSI) Series – No.2, UNESCO
Publishing, Paris.
13) Winrock International India; Institute for Studies and Transformations; Jadavpur
University. Department of Economics; Eco Friends; Spatial Decisions; Youth for
Unity and Voluntary Action (YUVA). 2006. Urban wastewater: Livelihoods, health
and environmental impacts in India. Research report submitted to
Comprehensive Assessment of Water Management in Agriculture. New Delhi,
India: Winrock International India. 27

Appendix A: Relevant tables from ISO 16075:2020

Table A-1: Categories of treated wastewater quality according to chemical, physical and biological parameters
Cat. Type of TWW BOD TSS Turbidity Thermo-tolerant
coliforms
Intestinal
nematodes
Potential uses without
barriers
Potential corresponding treatment
mg/l mg/l NTU no./100 ml Egg/l
Avg. Max Avg. Max Avg. Max 95 %ile Max Avg. Max
A
Very high quality
TWW
≤5 10 ≤5 10 ≤3 6
≤10
or below
the
detection
limit
100 — —
Unrestricted urban irrigation
and agricultural irrigation of
food crops consumed raw
Secondary, contact filtration or
membrane filtration and disinfection
B High quality TWW ≤10 20 ≤10 25 — — ≤200 1000 — —
Restricted urban irrigation
and agricultural irrigation of
processed food crops
Secondary, filtration and disinfection
C
Good quality
TWW
≤20 35 ≤30 50 — — ≤1000 10000 ≤1 —
Agricultural irrigation of non-
food crops
Secondary and disinfection
D
Medium quality
TWW
≤60 100 ≤90 140 — — — — ≤1 5
Restricted irrigation of
industrial and seeded crops
Secondary or high-rate clarification with
coagulation, flocculation
E Extensively TWW ≤20 35 — — — — — — ≤1 5
Restricted irrigation of
industrial and seeded crops
stabilization ponds and wetlands
Source: ISO 16075-2:2020 - Guidelines for treated wastewater use for irrigation projects
28

Table A-2: Suggested number of barriers (degree of barriers) that are needed for irrigation with TWW according to their quality
Type of treated wastewater Category Irrigation of
private
gardens and
gardens
landscape
with
unrestricted
public
access
Irrigation of
gardens and
landscape
with
restricted
public
access
Irrigation of
vegetables
consumed
raw
Irrigation of
vegetables
after
processing
and
pastures
Irrigation of
food crops
other than
vegetables
(orchards,
vineyards)
and
horticulture
Irrigation of
fodder and
seeded
crops
Irrigation of
industrial
energy crops
and in areas
where the
public has
no access
Very high-quality treated
wastewater
A 0 0 0 0 0 0 0
High quality treated wastewater B 1 0 1 0 0 0 0
Good quality treated wastewater C Forbidden 1 3 2 1 0 0
Medium quality wastewater D Forbidden 2 forbidden forbidden 3 1 0
Extensively treated wastewater E Forbidden 2 forbidden 2 2 0 0
Raw wastewater — Forbidden forbidden forbidden forbidden forbidden forbidden Forbidden
Source: ISO 16075-2:2020 - Guidelines for treated wastewater use for irrigation projects

29

Table A-3: Suggested types and accredited number of barriers
Type of barrier Application
Pathogen
reduction (log
units)
Accredited number of
barriers (Degree of
barrier)
Irrigation and food crops
Drip irrigation
Drip irrigation of low-growing crops such as 25 cm or more above from the ground 2 1
Drip irrigation of high-growing crops such as 50 cm or more above from the ground 4 2
Subsurface drip irrigation where water does not ascend by capillary action to the ground
surface
6 3
Spray and sprinkler irrigation
Sprinkler and micro-sprinkler irrigation of low-growing crops such as 25 cm or more from
the water jet
2 1
Sprinkler and micro-sprinkler irrigation of fruit trees such as 50 cm or more from the
water jet
4 2
Additional disinfection in field
Low level disinfection 2 1
High level disinfection 4 2
Sun resistant cover sheet In drip irrigation, where the sheet separates the irrigation from the vegetables 2 to 4 1
Pathogen die-off Die-off support through irrigation cessation or interruption before harvest 0.5 to 2 /day 1 to 2
Produce washing before selling to the
customers
Washing salad crops, vegetables, and fruits with drinking water 1 1
Produce disinfection before selling to the
customers
Washing salad crops, vegetables, and fruits with a weak disinfectant solution and rinsing
with drinking water
2 1
Irrigation of fodder and seeded crops
Access control
Restricting entry into the irrigated field for 24 h and more after irrigation, for example,
animal entering in pastures or entering of field workers
0.5 to 2 1
Restricting entry into the irrigated field five days and more after irrigation 2 to 4 2
Sun drying of fodder crops Fodder crops and other crops that are sun-dried and harvested before consumption 2 to 4 2
Irrigation of public gardens
Access control
Irrigation by night when the public does not enter the irrigated parks, sport fields, and
gardens
0.5 to 1 1
Irrigation where the public has no access (Interchange on the side of the road) 2 to 4 2
Spray irrigation control
Spray irrigation at distances greater than 70 m from residential areas or places of public
access
1 1
Note on log reduction: 0.5-log = 66.6%; 1-log = 90%; 2-log = 99%; 3-log = 99.9%; 4-log = 99.99%; 5-log = 99.999%
Source: ISO 16075-2:2020 - Guidelines for treated wastewater use for irrigation projects
30

31