No abstract

The management of contaminated areas with multiple sources of contamination (megasites) is among the biggest challenges for the Brazilian environmental agencies, especially because aquifers in big urban areas, like the Sao Paulo Metropolitan Region, are important sources of water for human supply purposes. One of the main reasons that hamper the proper management of urban environmental problems is a lack of a unified system where all information can be easily integrated into regional studies. To address this problem, a method for data integration and management using a Geographic Information System (GIS) was developed. This method was applied to the case of a regional contamination of an aquifer by chlorinated solvents at a former industrial district in Sao Paulo city, named Jurubatuba, but the final product might also be used for data management of contaminated areas for the entire State of Sao Paulo. The main result obtained was that the site-by-site approach for aquifer contamination management is ineffective. Furthermore, there are many other suspected and potential sources of contamination without any information available after more than 10 years since the contamination problem was discovered at the FIZ 131.

The integrated analysis of geophysical loggings for identifying transmissive fractures has had a limited use in Brazil, although a large number of studies have been conducted so far throughout the world. The application of those tools has gained a crescent importance as they are needed for characterizing groundwater contamination in fractured rock aquifers at a great number of industrial sites worldwide and in Brazil. This paper presents the analysis of data collected by caliper, optical televiewer (OPTV), acoustic televiewer (ATV) and flowmeter loggings in four deep supply wells located in the industrial area of Jurubatuba, city of São Paulo. Five fracture sets (G1 through G5) were identified based on OPTV and ATV borehole loggings. The main fracture set (G1), NE-striking with low to intermediate dip, is subparallel to the foliation, being at great extent the result of the reactivation of this previous discontinuity. Fractures on ATV and OPTV images were visually classified with regard to flow evidence, and a positive correlation between high flow evidence and significant flow rate, measured by a flowmeter, was identified. On the other hand, the majority of fractures with insignificant, low or intermediate flow evidence are located in depth intervals with no significant flow rate. Fractures that belong to G1 are of major importance for flow, as in 9 of the 16 intervals with significant flow, they are the only fractures present. Data were inconclusive regarding transmissivity of high dip fractures, because few of them were intercepted by the well boreholes. However, there is evidence that subvertical fractures of sets G3 and G5, NE and NW striking, respectively, are also transmissive, which corroborates outcrop observations. Although geophysical loggings are essential to identify the most important segments of boreholes for water input and output, and to collect detailed data of low dip fracture sets at greater depths, the structural geology characterization of fractured aquifers cannot rely on borehole geophysical loggings alone. For proposing realistic conceptual models of the fracture network, data from boreholes should be complemented with data from large rock exposures (quarries), in order to describe geometrical parameters, such as spacing, length, and physical connectivity of low, intermediate and high dip fractures, as well as evidence of flow along individual fractures.

A new version of the computer program FLASH (Flow‐Log Analysis of Single Holes) is presented for the analysis of borehole vertical flow logs to estimate fracture (or layer) transmissivities and far‐field hydraulic heads. The program is written in R, an open‐source environment. All previous features have been retained and new features incorporated including more rigorous parameter estimation, uncertainty analysis, and improved data import. The program has a dynamic user interface compatible with most operating systems.

Primeiramente agradeço ao meu orientador, o Prof. Dr. Reginaldo Antonio Bertolo, pela confiança e oportunidade de participar do Projeto GESOL. Seu apoio foi fundamental para aproveitar ao máximo todas as oportunidades que surgiram no decorrer do caminho. A sua amizade e bom humor tronaram esse caminho mais fácil. Agradeço à FAPESP pelo apoio e pela bolsa de mestrado, tornando possível o desenvolvimento desta pesquisa e a experiência de estudar e trabalhar no Canadá. À Universidade de São Paulo e ao instituto de Geociências pela estrutura e a oportunidade de fazer parte da história dessa Universidade que é tão importante para o Brasil. Agradeço também ao professor e amigo Rodrigo Cunha que me deu apoio e incentivo para entrar no mestrado e é fonte de inspiração para me tornar um profissional melhor. Este trabalho teve a contribuição de muitas pessoas e instituições, as quais sou muito grato. Todos foram importantes para minha formação profissional e como ser humano. Deixo um agradecimento em especial para: À divisão de áreas contaminadas da CETESB, nas pessoas de Rodrigo Cunha,