Re: Brazil Water Issues
Coliform bacteria also a problem:
Conversely, TC and FC positive samples appear to be
similar and seasonally influenced in treated water,
with the highest counts seen during the months of
September to March and falling from April through
August. Data fell into two clearly defined periods,
spring and summer (September through March) when
counts increased, and fall and winter period (April
through August) when counts decreased.
http://www.scielo.br/pdf/rsp/v37n2/15291.pdf
Guarani Aquifer System (SAG) is the formal denomination for a transboundary aquifer
underlying four countries (Argentina, Brazil, Paraguay and Uruguay) in South America. Due to
its strategic importance, a joint research project aiming for sustainable management and
preservation of the aquifer was initiated by the four neighbour countries together. In this work,
an overview of hydro-geological characteristics as well as basic information on availability,
quality and management efforts are presented.
Many pollutants contaminate rivers and lakes through punctual sources, as
sewers canalizations, or diffuse sources, as the case of draining waters (runoff) that carry
pesticides and fertilizers.
In Brazil, 92 % of the sewers are launched in the rivers and 8 7% of the
wastes are deposited under rain influence. Under these conditions, the use of superficial
water (rivers, dams and lagoons) only becomes viable in the absence of groundwater
sources. The filtration processes and bio-geochemical reactions that take place in subsurface
assure a good quality to groundwater, which is naturally protected against the pollution that
reach rivers and lakes.
However, the countries’ legal frameworks for managing and monitoring groundwater use
have not accompanied the rates of extraction and expansion of groundwater use.
Missing
control on wells design and closure seems to have caused wells to act, in some cases, as
open channels for surface contamination. In regions of the aquifer system, where water
quality is being monitored systematically (like in CETESB’s well-functioning monitoring network
in São Paulo State),
inorganic contamination (high nitrate content) and anomalous pesticide
traces have been detected. This is also assumed to be occurring in other regions of the
Aquifer, particularly in outcrop areas, showing high natural vulnerability, and in semi-confined
areas, showing an effective connection with overlying unconfined and contaminated
aquifers.
Recently, in the central west region of Santa Catarina State, Brazil, hydro-geochemical
investigations detected pollution in deep wells in the Serra Geral Aquifer system, representing
local contamination risk for the Guarani System through fractures in the basalt formation.
The
analyses indicated the presence of phosphate and nitrate in levels above the accepted for
human consumption, being attributed to intense practical of swine farming and extensive
agriculture, especially soy and maize (ALMEIDA, 2004).
http://www.tt.fh-koeln.de/publications/ittpub302101_21.pdf
