A aplicabilidade da resolução CONAMA nº 357/2005 no enquadramento dos corpos d’água na bacia do Rio Purus: um instrumento válido para as águas amazônicas?

Abstract

The present research has as main objective to evaluate the applicability of the Water Bodies Framing, planning instrument of the National Water Resources Policy, for the classification of waters of the Amazon region. The current normative is the CONAMA Resolution nº 357/2005, in substitution of CONAMA Resolution nº 20/1986. In the Amazon State, the Water Resources Policy is still in an implementation phase for the State Politics, having as conceptual legal framework the Law nº 3,167/2007 regulated by the Decree nº 28.678/2009. It is well known that Amazonian waters are part of a complex ecosystem with great chemical and ecological differences. Therefore, a water classification based on current standards or criteria are unreal and a revision or adaptation of the legal framework based on regional typology and water body dynamics of the Amazonian region. This study was undertaken on the Purus River Basin as a model of the environmental and socioeconomic variability in the region, besides being a transboundary river. Statistical test t was used for comparisons between the average water parameter values and standard values established in CONAMA Resolution nº 357/2005 for water Class 1, for water bodies of the Purus River Basin between the cities of Beruri and Lábrea. This legal framework inserts regional waters in levels of classification for less restrictive uses; however the waters of the Purus River Basin and its tributaries reflect the natural features of Amazonian waters. The null hypothesis has been accepted, and then the Purus River Basin water can be classified as Special or Class 1 waters. The current legal framework, CONAMA Resolution nº 357/2005 that established water quality criteria and standards can be applied in the Amazon region with the introduction of some additional criteria mainly for oxygen, for all water types and pH for black waters.