Submitted by:Mouez Gaaloul
The
SociÈtÈ Nationale d'Exploitation et de Distribution des Eaux / SONEDE
(National Water Distribution Utility) was created by the law No. 68-22 of
July, 2nd 1968. It is under the supervision of the MinistËre de
l'Agriculture de l'Environnement et des Ressources Hydrauliques (Ministry
of Agriculture, Environment and Hydraulic Resources). It is a public
entreprise of a non administrative nature.
SONEDE's
object is to supply all the country with drinking water. It is entrusted
with the exploitation, maintenance and renewal of facilities for water
capture, transportation, treatment
and distribution. Its mission covers the following main activities:
*Water production, treatment and transport.
*Water distribution: management
and maintenance of drinking water network and equipment and management of
customers.
*Development:
studies, works and supply.
To achieve these goals The SONEDE started by setting up of structures and
adequate management modes for water resources and supply of large urban
centres with drinking water, the main projects being:
- A
120 km long adduction to bring the waters from the Kasseb dam (north of BÈja)
to Tunis.
- The Tunis - Cap Bon adduction.
- The reinforcement of the network of Bizerte, Beja,
Sahel, Sfax, Gabes, Djerba and the regions of the centre of the country.
- The elaboration of the Master Plan for the Waters of the North in order
to transfer water from the North west to high comsumption centres situated
on the littoral of the country.
- The reinforcement of transfer water facilities in the areas of Sfax and
the South of Tunisia.
- The achievement of several drinking water supply projects in
middle-sized urban cetres and rural villages.
Submitted
by: Ibrahim Chaouch
3- Does scarcity affect the quality of water?
It is
important to note that the southern part of the country with a higher
solar radiation is the region where the problem of fresh water
shortage is most acute.
Recently, a number of
research experiments have been undertaken (or are underway) in Tunisia for
the study of coupling between desalination units and solar thermal Energy.
Safi has coupled a multiple-stage flash distillation (MSF) plant with a
solar pond. Bouguecha et al. Have
performed a feasibility study of coupling between a multiple distillation
and flashing (MDF) plant and
a solar pond for seawater desalination. A cogeneration desalination
project has been conceived and consists of coupling an MSF plant for
desalting seawater (capacity: 2500 m3 / d) to an already
existing 25 Mwe gas turbine electricity generator .The innovative feature
of this cogeneration project is the use of a heat storage pond for storing
the waste heat recovered from the gas turbine generator. Ben Jabrallah and
Belghith have investigated a solar distillation plant with a
multiple-effect distillation configuration. Ben
Becha et al. Have
studied a solar multiple condensation evaporation cycle (SMCEC) plant for
brackish water desalting.
In
Tunisia, a number of places with geothermal spring have been known for a
long time, some of which have been used for bathing and therapeutic
treatments (e.g., korbous, El-Hamma, and Hammam-Zriba). Recently,
geothermal groundwater sources destined for irrigation are a priori used
for heating agricultural greenhouse; as a result, a considerable increase
in greenhouse farming has been recorded in recent years. Most geothermal
sources in Tunisia have low enthalpy with maximum temperatures of 70-90 C.
Nevertheless, the northwestern part of the country is characterized with a
geothermal zone of high energy. Ben Dhia subdivided the country into five
major geothermal districts. Recorded hot spring temperatures range from 21
to 73 C with flow rates of 0.1 to 401/s. Shows the regions of the country
with known geothermal sources. These sources can be found not only in the
northern part of the country where desalination is least needed, but also
along coastal regions and in the south where the fresh water problem is
most acute. Coastal towns, tourist resorts and islands are characterized
with high population factors and huge influxes of summer tourists and
visitors causing a dramatic increase in the demand for potable water.
Southern parts of the country, on the contrary, have a lower population
density. However, available groundwater resources in the south are mostly
brackish.
The geothermal brackish
groundwater of the chott El-Fejij (70 km from the city of Gabes) (2.8
g/l,70 C) is actually dropped down to 30 C by coolers. This brackish water
is used to feed the reverse osmosis desalination plant in the city of
Gabes at a flow of 2000 m3/h. The cooling operation of
groundwater rejects in the atmosphere an important quantity of thermal
energy, estimated to be 8x107 kcal/h.
Submitted
by: Abir Jomaa & Ibtihel Fkih Romdhane
The
distributed water undergoes a double bacteriological control by the
relevant services of SONEDE and the Public Health Ministry. The results of
tests are in accordance with the standards of the World Health
Organisation (WHO).
The quality of the water distributed in the South - East of Tunisia has
been improved thanks to the achievement of the brackish water desalination
plants of GabËs, Zarzis and Djerba.
Submitted
by Olfa Haj Ayeche
4- Are people aware of the importance of saving water?
Thanks to
campaigns and the efforts of national and local authorities, most people
are aware of the water problem in the country. However, many do not care
about it. They are either indifferent or they do not implement what they
learn in their daily practises. In fact, most people care about the water
bill more than the water waste. If they regulate their consumption, it's
not for the sake of saving water but rather to pay less. Luckily they
result in the same practice.
Submitted
by Rahma Bouzwache
5- What efforts are done by authorities to reduce water consumption?
The Water and Sanitation for Health Project (WASH), and the Tunisian
Ministry of Agriculture on a plan to deliver potable water to rural areas.
To encourage ownership and self-management of pump equipment and water
distribution networks, as well as greater awareness of water conservation
and hygiene, we designed and developed a comprehensive communications
program including advertising and broadcast and printed media. The project
was cited in an article in Jeune Afrique as playing an integral role in
extending the life of Tunisia's water reserves.
Submitted
by : Ibtihel Fkih Romdhane
The water conservation strategy that SONEDE is implementing is based on a
set of measures related to technical, organisational and financial
aspects.
The
technical aspect is very important in this strategy. The actions which are
carried out in this framework basically deal with the control of network
technical management, the detection and repairing of pipe leaks and the
generalisation of the use of corrosion-resistant equipment.
At the
organisational level, regional structures have been set up to ensure the
follow up of actions. Night and day duty teams are mobilised to intervene
to repair ruptures and leaks of pipes.
The financial
aspect is concretised by controlling drinking water demand through an
adequate tariff system.
Consciousness
raising campaigns for water conservation are carried out through
mass-media an direct contact.
Training
courses are periodically organised for the personnel in charge of water
equipment maintenance.
Submitted
by: Soumaya
Mahjoub
6- Are there any pilot experiments to preserve or use already consumed
water?
In Tunisia, an
experimental desalination station for brackish and seawater desalination
using renewable energies (mainly solar and wind) was built in 1981 within
the National Institute for Scientific Research (INRST) at its site of
Borj-Cedria on the southern suburbs of Tunis City. This experimental
desalination station includes: ……
a reverse osmosis pilot plant for seawater desalination with a capacity of
0.25 m3 /h.
Wind energy has been
exploited for water pumping for a long time in many parts of the country
using traditional windmills.
Submitted
by: Marwa Mlouka
A pilot experiment has been started in a primary school in a town
called Gafsa by the environment club. It consists in re-using the water
already consumed by students for washing hands and drinking to water the
school garden by buiding canals from the robinets to the plants and lawn
at school. We've heard of the experiment on TV but we haven't had the
chance of visiting the school.
Submitted
by Rahma Baanannou