MIHAI BRETOTEAN

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THE DEVELOPMENT OF A MANAGEMENT SYSTEM OF
GROUNDWATER RESOURCES OF FRATESTI AQUIFER
LAYERS IN THE CITY OF BUCHAREST
MIHAI BRETOTEAN Head of Groundwater Department
- National Institute of Hydrology and Water
Management Bucharest, Romania
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I. THE CURRENT PROBLEMS OF THE EXPLOITATION OF
THE FRATESTI AQUIFER LAYERS IN THE CITY OF
BUCHAREST (1) The depth aquifer system
of the Fratesti Layers (A, B and C), Romanian -
Early Pleistocene in age, represents a strategic
source of water supply of the city of Bucharest.
Due to the structural rising of Fratesti
Layers, from North to South, these layers join
at South of Bucharest the alluvia from the
Neajlov and Arges floodplains, in their
confluence area (Fig. 1). The water of the
phreatic aquifer layer from alluvia of these
rivers is polluted with organic substances, NH4
and NO2 (Fig. 2).
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I. THE CURRENT PROBLEMS OF THE EXPLOITATION OF
THE FRATESTI AQUIFER LAYERS IN THE CITY OF
BUCHAREST (2)
Fig. 1 Lithological sections in the Bucharest
area
Fig. 2 Space distribution of the water quality
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I. THE CURRENT PROBLEMS OF THE EXPLOITATION OF
THE FRATESTI AQUIFER LAYERS IN THE CITY OF
BUCHAREST
(3) As a consequence of the
over-exploitation of the water of the Fratesti
Layers aquifer system from Bucharest area,
especially of the upper aquifer layer A, but
also of aquifer layers B C, found in
hydraulic connection, through about 500 wells,
with a total discharge of about 1600 l /sec,
there were created large depressionary cones,
which determine the attraction of polluted waters
from the South part to the exploitation area of
Bucharest (Fig. 3 and Fig. 4). This is the
reason for which, according to the Water
Framework Directive 60 /2000 /EC, in the
Bucharest area, the Fratesti Layers aquifer
system must be considered at risk from the
quantitative and qualitative point of view.
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I. THE CURRENT PROBLEMS OF THE EXPLOITATION OF
THE FRATESTI AQUIFER LAYERS IN THE CITY OF
BUCHAREST (4)
Fig. 3 The piezometric surface of the A aquifer
layer
Fig. 4 The piezometric surface of the B C
aquifer unit
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II. THE POLLUTION RISK ASSESSMENT
(1)
The pollution risk of the Fratesti Layers
aquifer system, estimated on the basis of a
groundwater dynamic model of double-layer finite
element type (the layers A and B C) in steady
state and a pollutant transport model based on
the transport equation for the miscible
substances in a porous medium as follows
(Marsily, 1986) D seeming dispersion tensor
(m2/day ) C mass concentration of the
dissolved substances (kg dissolved substance /kg
fluid) V filtration velocity (m /day) nc
cinematic porosity (undimensional) t variation
span of the mass concentration (days)
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II. THE POLLUTION RISK ASSESSMENT
(2)
The filtration velocity results from this
relation   K hydraulic conductivity (K T
/M, where T Transmissivity and M aquifer
thickness) in m /day H piezometric head
(m) grad mathematical operator  
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II. THE POLLUTION RISK ASSESSMENT
(3)

• The pollution risk, expressed by the
  calculated evolution of the pollutant relative
  concentration, considered as an ideal tracer (the
  pollutant propagation velocity is equal with the
  water average velocity, in lack of the labeling
  tests), is presented as follows (Fig. 5 and Fig.
  6)
• in the case of the layer A, the relative
  concentration, in the southern part of Bucharest,
  is 25 after 5 years, 50 after 15 years, 75
  after 30 years and 80 after 60 years when the
  process can be considered stabilized in the
  central area of Bucharest, after 60 years, the
  pollutant relative concentration is about 30
• in the case of the complex B C, the pollutant
  transport evolution is much slower, so that after
  30 years, when the process can be stabilized, the
  pollutant relative concentration in the Southern
  part of Bucharest is only 20 , without the
  center of the city being affected by pollution.

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II. THE POLLUTION RISK ASSESSMENT
(4)
Fig. 5 Distribution of the relative
concentration in aquifer layer A, after 60 years
Fig. 6 Distribution of the relative
concentration in aquifer unit B C, after 30
years
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III. MEASURES FOR CREATING A WATER RESOURCES
MANAGEMENT SYSTEM OF THE FRATESTI AQUIFER
LAYERS IN THE AREA OF BUCHAREST CITY
(1)

• Ist stage
• This stage is in progress and consists of
• - the determination of the present situation of
  the Fratesti Layers in Bucharest area and at
  South of it wells inventory, piezometric
  surfaces, yields, hydrogeological parameters
  (which will be determined by pumping and labeling
  tests in existent wells) and water quality
• -  the monitoring wells network settlement, which
  will include both existent wells and, if it is
  the case, new wells, as well as possible
  hydrometric stations in the Neajlov and Arges
  rivers.

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III. MEASURES FOR CREATING A WATER RESOURCES
MANAGEMENT SYSTEM OF THE FRATESTI AQUIFER
LAYERS IN THE AREA OF BUCHAREST CITY
(2)

• IInd stage
• In the second stage,there are projected the
  following actions
• -  the equipment (sensors) obtaining and
  installing for the water levels automatic
  measuring, both in the monitoring wells and in
  the case of the Neajlov and Arges rivers, as well
  as for water quality ( NH4- , NO2-, NO3- ,
  organic substances)
• - a monitoring program settlement and
  implementation, including a data transmission
  system, in real time, in a database
• - a database creation, including a specific
  software, for data collection and validation and
  for supplying some mathematical models of the
  groundwater dynamic and pollutants transport,
  coupled with GIS techniques

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III. MEASURES FOR CREATING A WATER RESOURCES
MANAGEMENT SYSTEM OF THE FRATESTI AQUIFER
LAYERS IN THE AREA OF BUCHAREST CITY
(3)
IIIrd stage On the basis of the obtained data in
the previous stages, there will be achieved the
following actions - - the improvement of the
groundwater dynamic and pollutant transport
mathematical models, already made, according to
those specified in the first chapter, for the
Bucharest area and the polluted area situated at
the South of it, till the Neajlov and Arges
rivers - - the elaboration of some scenarios
based on conceived models for establishing the
exploitation optimal solution of the Fratesti
aquiferous Layers in the city of Bucharest,
depending of the groundwater quality evolution
South of this city and of attracted yield from
the Neajlov and Arges rivers, as well as of some
solutions for the surface and groundwater
cleaning and protection in the area South to
Bucharest - -  the settlement of a
hydrogeological protection perimeter in the join
zone of the Fratesti aquiferous Layers with
alluvia from the Neajlov and Arges floodplains.
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III. MEASURES FOR CREATING A WATER RESOURCES
MANAGEMENT SYSTEM OF THE FRATESTI AQUIFER
LAYERS IN THE AREA OF BUCHAREST CITY
(4)
  The management system created in this way,
concerning the exploitation and pollution control
of the Fratesti aquiferous Layers, is going to
be delivered to the local water management
authority, in order to become functional at the
end of the project. Thanks for attention!