Management of contaminated areas by gas stations in Cuiabá, Mato Grosso, Brazil

Abstract

The commercialization of petroleum-based fuels is a potentially polluting activity. Environmental impacts are mainly due to tanker truck accidents and leaking underground storage tanks of gas stations. The management of contaminated sites aims to reduce risks to human health and environment through measures that provide knowledge regarding the characteristics of contaminated site and the impacts of contaminants, thus allowing the most appropriate intervention to be determined. This paper analyzed the environmental licensing process of the Cuiaba-MT gas stations in order to present an overview of the gas stations responsible for some type of environmental contamination, since the investigation of liabilities is required for this license. One hundred and thirty-six licensing processes were analyzed, and it was found that 17 of these reported some type of contamination in soil and/or groundwater. The main contaminants were Benzene, Toluene, Ethylbenzene and Xylenes (BTEX) and Polycyclic Aromatic Hydrocarbons (PAHs). The following remediation techniques were applied: three cases of natural attenuation, three of multiphase extraction and three of pumping. This highlights the necessity for the State Environment Agency to make available information about contaminated areas not only in Cuiabá but throughout the State. According to CONAMA Resolution 420/2009, this is an obligation of the environmental agency for the management of contaminated areas to be effective. It is also important that the Mato Grosso State establish public policies for the management of contaminated areas, with legislation specific to the issue, as some other Brazilian states have done.