Sibele Ezaki

Proposta de classificação das fontes potenciais de contaminação da água subterrânea

The identification of activities with the potential for groundwater contamination aids in the prioritization of actions to protect water resources, especially in areas with significant urban and economic development. This study presents a survey of potential pollution sources in the municipalities of Capivari, Elias Fausto, Indaiatuba, Monte Mor, Rafard and Salto (State of Sao Paulo) and proposes a classification of the associated contaminant load in order to identify the areas of highest hazard of groundwater contamination in this region. The classification developed here is called POSH-IG and is adapted from the renowned POSH (Pollutant Origin, Surcharge Hydraulically) method, which ranks the contaminant load of the potential pollution sources in three qualitative levels (low, moderate and high) based on the origin of the contaminant and the presence of a hydraulic surcharge promoting advective transport to the aquifer. In the POSH-IG method adjustments were made for the classification of the contaminant load of point sources, inserting available parameters from the Environmental Licensing System of Sao Paulo State. Land use mapping, the type and pattern of occupation was integrated to classify the contaminant load of diffuse pollution sources associated with sanitation systems in urban areas and farming and livestock activities in rural areas. Besides the evaluation of urban expansion areas, the density of occupation of residential, commercial, and services areas - an indirect indicator of population density - was also considered as a criterion for classification of diffuse sources related to sanitation systems. Of the 1918 point sources of contamination registered in this study, the activities with highest contaminant load are mainly related to the chemical, metallurgical, metal product, electronics and mechanical engineering industries, storage of hazardous products and inadequate waste disposal. In urban areas the greater potential contamination load from diffuse sources is concentrated in the older portions of the cities where higher occupation densities occur. The largest such areas occur in the municipalities of Indaiatuba and Salto, where there has been intense urbanization and in Monte Mor, where less than 45% of the city is servedby the sanitary system. In rural areas, sugar cane cultivation, prevalent in the municipalities of Capivari and Rafard, stands out because of its high potential for groundwater contamination.

Perigo de contaminação da água subterrânea na região de Indaiatuba a Capivari, estado de São Paulo, Brasil

The mapping of groundwater contamination hazard is a helpful tool for planning land use, identifying priorities for controlling human activities and for protecting groundwater sources. Considering hazard as a result of the interaction between the aquifer natural vulnerability and the potential contaminant load imposed by human activities, in this study, the classification system for groundwater contamination hazard was adapted to allow mapping based on spatial analysis techniques in GIS (Geographic Information System). The groundwater contamination hazard was mapped in an area comprised by six cities, which are located in the eastern part of Sao Paulo State, Brazil, and experienced significant economic development and accelerated urban expansion. The groundwater contamination hazard map associated with point sources of contamination indicated that critical areas are located in the industrial districts of Indaiatuba and Salto and are scattered along the Capivari River and highways. In urban areas, the risk of contamination associated to leakage of sewage systems is concentrated in older parts of the city with high density of occupation. In rural areas, the risk of contamination is high or moderate mainly in the western portion of the study area, which is dominated by sugarcane monoculture. With regard to diffuse contamination sources, there is a predominance of areas with moderate to very low contamination hazard resulting from the low aquifer vulnerability in the region. Considering the dynamics of land use, the groundwater contamination hazard map must be regularly updated to better support groundwater management and land use planning and geoprocessing tools can facilitate this task.

Geometria do aquífero tubarão entre os municípios de Indaiatuba e Capivari (SP)

The Tubarao Aquifer (Parana basin), despite the low productivity, is a significant public and private source of groundwater for the Metropolitan Region of Campinas and for the municipalities located between Sorocaba and Campinas (Sao Paulo State). Hydrogeological studies carried out in the 1990s showed the occurrence of potentiometric surface drawdown due to intensive pumping of wells, indicating the need to evaluate its productivity potential. Thus, this study aimed at characterizing the geometry of the aquifer located between the municipalities of Capivari and Indaiatuba (SP). Lithostratigraphic cross sections from east to west were prepared and analyzed based on 1262 pieces of data from wells. Correlations between these cross sections and geologic, potentiometric, and sandstone thickness maps, as well as structural contour maps of the top of the crystalline basement, provide a three-dimensional view of the lithological bodies, which helps in the location and construction of new wells, serves as the basis for stratigraphic and paleoenvironmental studies and improves the utilization of groundwater. The results showed that the most productive regions are usually located where the wells cross great thickness of sandstone (up to 200 to 300 m depth). These regions are: 1 - central region of Capivari Municipality; 2 - northeast and central-northwest regions of Elias Fausto Municipality; 3 - central-northeast region of Monte Mor Municipality. In the latter, the significant lateral continuity of sandstones, which are overlaid by shales and mudstones, locally causes the aquifer confinement.

CARACTERIZAÇÃO HIDROQUÍMICA DAS ÁGUAS SUBTERRÂNEAS NO MUNICÍPIO DE ITU (SP)

Hydrochemical study in Itu city (Sao Paulo State) was performed in the 1990s as part of a hydrogeological characterization related to the planning of groundwater use in the Sorocaba-Campinas region, an area of increasing urbanization and industrialization. Analytical results of 50 well samples indicated the predominance of calcium bicarbonate water in the Crystalline Aquifer, and of sodium to calcium bicarbonate water in the Tubarao Aquifer. The waters are considered to be appropriate for agricultural use and livestock. However, for human consumption, the water of some wells is not potable and does not meet the bacteriological standards of the Health Ministry (Ordinance 2914, of 12/12/2011), which is probably associated with problems of sanitary protection (presence of fecal coliforms in 5 wells and total coliforus in 13 wells). High concentrations of iron and/or manganese have also been observed in 16 wells and may be associated with geological features or construction problems. There is an anomalous concentration of fluoride probably related to mineral alteration of granitoid rocks.