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E-mail CONFERENCE
(June 24 –July 5)
AGRICULTURAL USE OF untreated URBAN WASTEWATER IN LOW INCOME COUNTRIES
BACKGROUND
Use
of urban wastewater in agriculture
Globally on an average 47% of the population live
in urban areas. Even at the lower consumption
figures of 100 –150 litres per capita per day the
water consumption in Africa would be 45 mill m3 and
in Asia 200 mill (Water and sanitation assessment
report prepared for the 2nd World Water Forum). Most
of this water returns as waste.
On the other hand agriculture consumes more than 70
percent of exploited water resources globally and
cities are increasingly competing for water with
agriculture.
With increasing water scarcity, it is mandatory to find
alternative sources of water for irrigation. One
such means is to enhance the use of urban wastewater
transforming wastes into a resource to yield
products needed by the population.
The
use of the urban wastewater in agriculture is a
widely established practice, particularly so in
urban and peri-urban areas of arid and seasonally
arid zones.
Wastewater is used as a source of irrigation water
as well as a source of plant nutrients (such as
nitrogen, phosphorus and potassium) and trace
elements (K, Na, etc) allowing farmers to reduce or
even eliminate the purchase of chemical fertilizer
and of organic matter that serves as a soil
conditioner and humus replenisher
Lunven (1992) estimated that one tenth or more of the
world’s population currently eats food produced on
wastewater (but not always in a safe way).
In the developed world planned
use (of treated wastewater) is more common, as
is evident in Israel, Australia, Germany, and the
USA. A
literature review (Haruvy,1997) indicated that
Israel is at the forefront of planned
wastewater use with fully 70 % of the total
agricultural demand for water in 2040 to be met by
treated effluent.
For
developing countries like India,
Pakistan, China and Mexico, to quote a few examples,
wastewater for irrigation originated as an unplanned often spontaneous activity and has been practiced for decades and even centuries by poor
farmers in urban and peri-urban areas. Studies
have concluded that an estimated 80% of wastewater
may be used for irrigation, with China and South
Asia making significant use of untreated waste for
irrigation (Mara and Cairncross, 1989). In Latin
America alone at least 500,000 ha of land is being
irrigated with untreated wastewater, over half of
which is in Mexico (Rodriguez et al, 1994). The
same is the case in Africa where case studies (Bakker
et al, 2000) in major cities in Africa (Accra,
Dakar, Nairobi,) indicate the extensive use of
wastewater.
Current
wastewater use practices in developing countries
includes official distribution of primary or
secondary treated wastewater (i.e. after mechanical
and biological treatment), the use of diluted
wastewater from urban waterways and
farmers accessing raw wastewater from open
drains or buried trunk sewers.
The informal use of untreated wastewater by
intra-urban and peri-urban farmers and gardeners is
the most common situation. For large groups of poor
citizens (as well as for some better off) access to
wastewater is the main factor that determines their
food security and income generating capacity.
Without the wastewater their production would be
limited to the rainy period and productivity would
be minimal.
Health
and environmental risks
However,
irrigating with untreated
wastewater poses serious public health risks, as
sewage is a major source of excreted pathogens
- the bacteria, viruses, protozoa- and the helminths
(worms) that cause gastro-intestinal infections in
human beings.
Wastewater may also contain highly poisonous chemical toxins from
industrial sources.
Relevant
groups of chemical contaminants are heavy metals,
hormone active substances (HAS) and antibiotics. The
risks associated with these substances may, in the
long run, turn out to constitute a greater threat to
public health and be more difficult to deal with
than the risks from excreted pathogens.
Unregulated and continuous irrigation with sewage water may lead to
problems such as soil structure deterioration (soil clogging),
salinisation and
phytotoxicity.
The
abovementioned risks are not limited to official
wastewater but often also apply to rivers and other
open water sources, as indicated by figures gathered
by Westcott: 45% of 110 rivers tested carried faecal
coliforms levels higher than the WHO standard for
unrestricted irrigation (FAO, unpublished, cited in
Birley and Lock, 1999).
Treatment
of wastewater
In order to prevent health risks treatment, is normally
recommended as the main solution. There exists a
large array of technological and process options for
wastewater treatment. Centralised, technologically
complex and capital-intensive treatment systems have
received the most attention to date. Decentralised,
low-cost options, eco-technologies and
eco-sanitation approaches have only recently
received more attention.
However,
in practice most cities in low income countries are
not able to treat more than a modest percentage of
the wastewater produced in the city, due to low
financial, technical and/or managerial capacity, the
quick and unplanned growth of the city and the
multiple and dispersed outlets of the wastewater.
In many cities a large part of the wastewater
is disposed of untreated to rivers and seas, with
all related environmental consequences and health
risks. The perspectives regarding the increase in
wastewater treatment capacity in these cities are
bleak. It may safely be assumed that urban farmers
and gardeners increasingly will use urban wastewater
for irrigation, irrespective of the municipal
regulations and quality standards for irrigation
water.
Alternative
and complementary measures
Against
this background the organisers have chosen to focus
this electronic conference on the strategies that
may be applied to reduce the health risks associated
with the use of untreated, partially treated or
diluted wastewater in agriculture whilst
maintaining or enhancing the social and economic
benefits for the poor urban citizens involved in
irrigated production.
Rather
than focusing on (end of pipe) treatment of
wastewater, we want to discuss:
a. Strategies to ensure proper
health risk management by the users of the untreated
or partially treated wastewater
b. Strategies to prevent and
reduce chemical pollution by industries of domestic
sewage water and rivers that are used for irrigation
Planning
for the improved management of wastewater for reuse
in urban agriculture encompasses a wide range of
aspects and activities. These comprise, among
others, stakeholders involvement (concepts and
operational patterns), strategic water resources
planning, treatment at the source of pollution and
separation of wastewater flows (especially between
household water and industrial wastewater), farmers
education on risk management strategies (e.g.
appropriate choice of crops and appropriate
selection and timing, of irrigation techniques),
improved institutional coordination (especially
between agriculture, health, sanitation sectors);
revision of municipal regulations and standards and
enforcement of regulations at farmers level and vis-à-vis
polluting industries, monitoring of the quality of
wastewater and agricultural products, and training
of professionals on sound alternatives for
sanitation and recycling, among others.
OBJECTIVE
To
exchange, analyse and discuss strategies – as
alternatives or complementary to wastewater
treatment – to reduce the associated health and
environmental risks of using “untreated”[1]
urban wastewater in agriculture, while maintaining
or enhancing the socio-economic benefits
INTENDED PARTICIPANTS
The conference is a platform to
facilitate exchange of experiences and debate
between:
 Urban
planners, representatives of municipal departments
and policy advisors
Researchers (universities, research centres,
thematic networks)
Technical
staff of NGO's, international and local projects,
and other persons that have interest in these
issues.
THEMATIC AREAS and KEY ISSUES
Topic
1: Strategies to ensure proper management by the
farmers of the health and environmental risks
associated with the use of untreated wastewater
Key Issues:
- Is
it meaningful to develop a typology for
wastewater that is being used for urban and
peri-urban agriculture? What categories of
“untreated” urban wastewater should be
distinguished?
- Will
the use of untreated wastewater in agriculture -in the country/city you report on- probably decrease
or increase in the coming decade? Why?
- What
are the health and environmental effects (positive/negative)
of using untreated, partially or unsuccessfully
treated or diluted wastewater in agriculture
that have been documented in your
country/city? Which categories of the population
are mainly affected? Can we speak -in the cases
you report on- of acceptable risks? Why yes or
no?
- What
are the socio-economic costs and benefits
of use of untreated wastewater in agriculture
that have been documented in your
country/city? Who are the main beneficiaries? Do
these costs/benefits justify local government
support and investment? Why yes or no?
- How
effective are the local policies and
regulations (national level, city level)
regarding use of urban wastewater in
agriculture? What policy has proven to work and
which not? Why? What are the main barriers for
the development of more effective policies and
regulations?
- How
effective are the local institutional
mechanisms with respect to the design and
implementation of strategies of wastewater use
in agriculture? What are the main shortcomings
and obstacles? How to improve? What actors
should be involved and in what role? In your
experience will local authorities be more
amenable to formulating realistic regulations if
costs and benefits were quantified?
- What
are the limitations and pre-conditions to the
application of crop restriction as
an effective instrument to reduce health risks
of use of untreated wastewater in agriculture?
What are the pros and cons? When to apply?
- To
what extent are farmer education and technical
assistance effective instruments to reduce
the health and environmental risks related to
reuse of untreated wastewater? When yes, when
no? What are the main issues that require
attention?
- Could
economic incentives and/or farmer
education provide an alternative to legal
restrictions to promote adequate crop choice and
wastewater management?
- Is
periodic monitoring of the quality of the
irrigation water and/or the produce, in the
areas irrigated with wastewater, a useful tool
in helping to reduce the health and
environmental risks? Are the present standards
for irrigation water quality realistic?
- What
are the strategies for improvement recommended
by the local farmers themselves?
- What
other strategies could be applied
effectively? On what experiences is your
recommendation based?
Topic
2. Strategies to ensure prevention and reduction of
industrial contamination of domestic sewage and
rivers that are used for irrigation
Key
Questions:
- Will the industrial discharge of polluted wastewater to rivers and
sewers increase or decrease during the
next decade in the country/city you are
reporting on? Why?
- Have local authorities in the city you report on; the capacity to
detect and monitor the sources of
industrially polluted wastewater, its disposal,
the concentration of hazardous chemicals in
domestic sewage and the levels of contamination
in rivers? What can be done to improve this capacity?
- What are the main barriers for industries to accept
strategies to reduce the generation of hazardous
wastes and to enhance the recycling of
industrial waste water. What are –in your
experience- the most effective strategies to
overcome these barriers?
- Is the provision of information and technical assistance (on
waste minimization and recycling strategies and
technologies) an effective instrument to reduce
the discharge of hazardous wastes in rivers and
sewers and to encourage waste reduction and
waste reuse and recycling? Why yes or no? Under
what circumstances?
- To what extent does the creation and enforcement of regulations
on the generation and discharge of hazardous
wastes constitute an effective control and
regulation instrument? Why yes or no? What
are important pre-conditions? How effective are
the actual regulations and what limits their
enforcement?
- Is –in your experience- the provision of economic incentives
an effective strategy to encourage waste
reduction and waste reuse and recycling? Why yes
or no? When to apply?
- In what ways can the separate disposal of industrial wastewater
and domestic wastewater be enforced? Under
what conditions?
- What are the strategies for improvement recommended by local
industries themselves? What are the
differences between “big” and “small”
polluters?
- What other strategies may be applied effectively? What are
their pros and cons?
- What can be the role and contributions of local NGO’s and
farmer organizations?
PROCESS OF THE DISCUSSIONS
During
the first week of the conference we will
focus the discussions in both topics on the analysis
of the actual situation and trends and the analysis
of the effectivity of certain strategies.
During
the second week of the conference we will
continue that discussion but with more emphasis on
the formulation of recommendations for policy
development and action planning.
REGISTRATION
You
can register
as an e-conference participant in two ways:
1. If
you have access to internet, you can fill in the
registration form available on the Conference
website: www.ruaf.org/conference
2. If
you DO NOT have internet access, then you can
register by sending an e-mail to urban-agriculture@etcnl.nl
with the following information:
* = obligatory information!
a. Language
choice *
(French/English/Spanish)
b. Topic
choice*
(Topic 1 or 2)
i.
Topic 1: Strategies to ensure proper management by farmers
ii.
Topic 2: Strategies to reduce industrial contamination
c. Title
(Mr, Ms, Prof, Dr)
*
d. Initials
of First Names*
e. First
name
f. Surname
*
g. Telephone
h. Fax
i. Email
address *
j. Personal
Profile* :
*
Municipal officer or Councillor
* an employee of a governmental
organisation
* an employee of an NGO
* a researcher
* a student
* other__________
k. Organisation
Name
l. Department
m. Function
n. Street
Address
o. P.O.
Box
p. City
q. Postal
code
r. Country
s. Organisation
Telephone
t. Organisation
Fax
u. Organisation
E-mail
v. Organisation
website
* =
obligatory information
Once
you have registered, you will receive a confirmation
e-mail and the discussion papers.
TO
JOIN THE DISCUSSIONS
The
e-conference will start with an e-mail welcoming
participants to the event and inviting them to take
part in the discussion.
You
can contribute in the following ways:
a.
If you want to make a contribution (up to 3
pages) to one of the discussion groups or want
to react one of the discussion papers, please send
an E-mail to the corresponding list address :
Topic
1: topic1@listserv.ruaf.org
Topic
2: topic2@listserv.ruaf.org
Please
note:
 you
must send your emails from the address you used for
registration, otherwise your message will not be
accepted by the listserv!:
 any
email sent to the listserv with an attachment will
be automatically rejected! You must include your
comments in the text of your message or by
submitting a paper (see point c).
b.
If you want to react on a message sent
by one of the participants, you open the
corresponding e-mail and click the reply button.
Please only quote the relevant parts of the original
message you are reacting on and delete the rest of
it.
c.
If you want to contribute with a more extensive
case study or paper (over 3 pages) you
can click on ‘add a paper’ on the website and
follow the instructions. If you do not have access
to internet, you can send an e-mail (with
your paper as attachment) to the conference
moderators (urban-agriculture@etcnl.nl).
When
you contribute a paper it will be published on the
website in the “case studies” section (see
below).
It
is worthwhile to start your contributions to the
discussion groups
with a brief indication of the type of
situation you will deal with:
In
topic 1: size of the city, type of wastewater used
(partially treated, diluted wastewater, direct use
of fresh wastewater, main source of the wastewater),
type of crops irrigated, irrigation techniques
applied.
In
topic 2: size of the city, type and size of
industries, direct and indirect linkages with
the quality of the irrigation water used in
urban agriculture.
CONFERENCE WEBSITE
During
the conference and a few months afterwards a special
website for the conference will be maintained. See: www.ruaf.org/conference
Here
a list of all participants will be published as well
as all the e-mail contributions in chronological
order of arrival, grouped per topic. The discussion
papers and papers sent by the participants will also
be available on the website (in the section “case
studies”).
OUTPUTS
The moderators will produce a summary of the
discussions in each group at the end of the first
and second week. At the end of the second week also
the conclusions and recommendations emerging from
the discussions will be drafted by the moderators
and send to all participants.
The
results of the E-conference, together with the
results of regional workshops on these topics in
West Africa and South East Asia, will be used to
prepare a policy paper on the use of untreated
wastewater for the World Water Forum in March 2003.
A
selection of the most interesting contributions to
the E-conference will be included in the special
issue of the Urban Agriculture Magazine on
this topic.
MORE INFORMATION
More information
on the e-conference can be obtained from the
moderators at: urban-agriculture@etcnl.nl
About the
organizERs
ETC
- Resource
Centre on Urban Agriculture (RUAF)
ETC
International is an independent professional -but
not-for-profit- organisation, which executes
programmes and projects, implements studies, gives
policy advice and organises training.
ETC’s
main objectives are to encourage and support local
initiatives aimed at sustainable development, to
strengthen local institutions and the participation
of local stakeholders in the formulation and
implementation of adequate policies and programmes
for sustainable rural and urban development.
ETC
has a strong record in natural resource management,
low external input agriculture, sustainable energy,
and integrated land use systems, both in rural and
urban environments.
The
Resource Centre on Urban Agriculture and Forestry (RUAF)
is funded by DGIS (Directorate General for
International Development Cooperation of the
Ministry of Foreign Affairs, the Netherlands) and
IDRC (International Development Research Centre,
Canada).
RUAF
aims at integration of urban agriculture in the
policies and programmes of national and city
governments and international organisations, by:
§
Collecting and disseminating research data and project experiences in the
field of urban agriculture a/o by maintaining
databases, publication of the Urban
Agriculture Magazine and the maintenance of a
website (www.ruaf.org)
§
Promoting networking, exchange of experiences and debate on key issues in
the field of urban agriculture by organising
electronic conferences and international workshops
in collaboration with regional institutes and
networks.
§
Provision of assistance to regional and local partners in the
organisation of policy seminars and training
workshops and the formulation of policies and action
programmes
§
ETC-RUAF closely co-operates with regional institutes that act as
regional focal points on urban agriculture: UMP-Lac
(Latin America), MDP (South and East Africa), IAGU
(West Africa), CEDARE (North Africa and the Middle
East), IWMI-India (South East Asia) and DUR (China).
Contact
Ir.
Henk de Zeeuw, co-ordinator RUAF
ETC,
P.O. Box 64, 3830 AB Leusden, the Netherlands
Phone
+31-33-4326001
Email:
h.dezeeuw@etcnl.nl
http://www.ruaf.org
IWMI-
International Water Management Institute
IWMI is
a non-profit scientific research organization
focusing on the sustainable use of water and land
resources in agriculture and on the water needs of
developing countries. IWMI works with partners in
the South to develop tools and methods to help these
countries eradicate poverty through more effective
management of their water and land resources.
Its mission is: Improving
water and land resources management for food
livelihoods and nature, for which it has set itself
the following objectives:
§ To identify the larger
issues related to water management and food security
that need to be understood and addressed by
governments and policymakers.
§ To develop, test and
promote management practices and tools that can be
used by governments and institutions to manage water
and land resources more effectively, and address
water scarcity issues.
§ To clarify the link
between poverty and access to water and to help
governments and the research community better
understand the specific water-related problems of
poor people.
§ To help developing
countries build their research capacities to deal
with water scarcity and related food security
issues.
IWMI's research is organized
around five themes that are:
§
Integrated
Water Resource Management for Agriculture
§
Sustainable
Smallholder Land and Water Management
§
Sustainable
Groundwater Management
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