Surgil ESIA Report - Volume III - EKN

“O’ZLITINEFTGAZ” PC
PFS “Surgil field complex costruction with valuable
components retrieval”
1.3.2 SURFACE AND UNDERGROUND WATERS
There are absent large surface waterways within the area of Surgil field, the region of
field concerns to arid category.
There are some channels of irrigation purpose in the region of location and small
lakes which are salt gathering sources.
The features of underground waters have great importance for anthropogenic
processes of natural environment pollution in connection with development of hydrocarbons
fields.
The territory is considered practically drainless under conditions of the common
drain of underground waters.
Weak inclination of the sea bottom defines spreading of sea hydrostatic pressure
distribution at the considerable distance, and weak permeability of deposits provides close
from a surface underground waters occurrence. In the considerable areas of the sea drained
part this level are bedded near to ground surface.
This process causes high degree of underground waters mineralization. As a result of
infiltration, capillary raising and evaporating processes the waters mineralization fluctuates
from 10 to 80g/l.
On separate sites of geo-morphological declines in a relief the salts concentration in
underground waters can reach 200-300g/l and more.
Surface deposits of low power (to several meters) on Ustyurt overlie more ancient
and are arid. Depth of underground waters occurrence level is 5-8 and more. Waters
mineralization is very high, sometimes reaches to 75-80g/l, composition is sodium chloride.
Underground waters are opened by short wells, rare rise in the form of descending
sources. To the summer end almost all sources and wells are dry up. During this period the
mineralization exceeds level of MPC for potable water and reaches 3 and even 7g/l.
In spring the waters are freshened by an atmospheric precipitation to 1.5g/l and less.
Water containing rocks are dated to lake and dealluvial facies. In the conditions of
construction of new objects in the Ustyurt territory and other close areas of the republic this
factor demands the especial account in development of nature-conservative measures and a
geological estimation of a modern situation.
Underground waters of Surgil field concern to Sudoch’ye hydro-geological area
which is in northern part of huge Ustyurt basin.
In cross-section of this basin there are allocated 2 hydro-geological stories. Ground
storey represents a zone of the complicated water cycle and includes uppertrias-jurassic,
neocom-aptsk and alb-turon water bearing complexes.
The upper storey is in a zone of free water cycle in cross-section of deposit of
neogene-quaternary water bearing complex. The ground and upper hydro-geological
Volume 2. Part 1. EIS Project for Surgil field construction
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