Assessment of the natural vulnerability of underground aquifer aiming at the hierarchization of locations for the implementation of water supply and sanitary sewage systems in the municipality of Ananindeua/PA

Abstract

The methodologies for determining aquifer vulnerabilities are currently used as tools to support proposals for the groundwater protection, associated to water management resources and planning and territorial ordination activities. In this context, the objective of this present work is the vulnerability assessment of an aquifer system of interest located in the municipality of Ananindeua, the state of Pará. To this end, the following activities were executed: survey and systematization of pertinent information to existing wells in the municipality of Ananindeua-PA; determination of the constituent parameters of the GOD method and the hydrogeological values of hydraulic conductivity and hydraulic transmissivity; extrapolating the pertinent information for all the interest area aiming the spatialization of homogeneous zones by degree of vulnerability e, finally, the hierarchization of locations for the implementation of water supply systems. With the completion of this present work, it was verified that most part of the area of interest has an aquifer system classified as unconfined, mixed lithological extracts and distance from the top to the water table less than 20 meters. These information, associated with the pattern of land use and occupation, based on the study of hydrogeologic values, enables the subsidy for decision-making regarding the most appropriate allocation of preventive investments with basic sanitation infrastructure, in order to minimize or nullify the associated risks of contamination in the referred area. However, to a better support for an efficient decision-making from the public managers and the actions of other social actors involved in the use and management of groundwater in the locality, it must be provided other information and complementary studies.