This publication provides guidance to water-sector decision makers and planners on how to deal with the quality dimension of groundwater resources management in the World Bank's client countries. There is growing evidence of increasing pollution threats to groundwater and some well-documented cases of irreversible damage to important aquifers. This guide has been produced in the belief that groundwater pollution hazard assessment must become an essential part of environmental best practice for water supply utilities. The guide is particularly relevant for the World Bank's Latin American and Caribbean Region, where many countries have initiated major changes to modernize their institutional and legal framework for water resources management, but may not yet have considered groundwater at the same level as surface water, because of lack of awareness and knowledge of groundwater issues and policy options.

This study examines how environmental issues have been addressed in the water sector in Brazil, within the context of activities of the Federal Government, generally, and those implemented under Bank sector operations, in particular. The core focus of the study lies in the management of water quality, as it affects both the users of raw water, and those who are primarily concerned with the disposal of wastewater. The report considers the following three sectoral areas concomitantly - water resources management, water supply and sanitation, and, the environment - thus limiting its review, and focus to those themes which are key to the over-arching issue of water quality. Water resources management in the country relied upon heavy investments in medium, and large scale projects that provided basic infrastructure for water uses. However, these have produced questionable impacts in terms of reducing poverty, and inequality. One of the reasons for this, has been the poor infrastructure management, which despite its importance, has been largely underestimated. While improvements in the utilization of existing infrastructure in the water sector remain critical, it needs to be complemented by incentives to both service providers, and water users. Moreover, low economic, environmental, and social returns from investments in the water sector, reflect the tendency to distract attention from the objectives in the design, and implementation of projects. Thus, an assessment of water quality goals is required, which should be based on systematic evaluations of the costs, and benefits of reaching alternative standards, and explicit social objectives.

El documento trata sobre la gestión del agua para la agricultura en general, incluyendo la irrigada y la de secano o temporal, tanto en grande como en pequeña escala. Incluyendo la microagricultura. La definición de agricultura que se aplicará será lo más amplio posible, incluyendo los cultivos para subsistencia, para comercialización y exportación, la acuicultura, la ganadería y el ámbito agroforestal. La seguridad alimentaria se interpretará en varios niveles, desde la autosuficiencia a escala regional y nacional a la alimentación y el sustento en el plano "micro" del hogar. Los aspectos ambientales incluirán la calidad del agua, de los ecosistemas acuáticos y terrestres, y la biodiversidad como un fin en sí mismo pero también como una fuente de bienes y servicios brindados por la naturaleza, incluyendo la pesca. Si bien, se pretende que el diálogo se centre en el agua para la agricultura y el ambiente, existen varios asuntos intersectoriales importantes que deben considerarse sobretodo en lo referente a la pobreza y la salud

Stream water quality is controlled by the interaction of natural and anthropogenic factors over a range of temporal and spatial scales. Among these anthropogenic factors, land cover changes at catchment scale can affect stream water quality. This work aims to evaluate the influence of land use and seasonality on stream water quality in a representative tropical headwater catchment named as Córrego Água Limpa (Sao Paulo, Brasil), which is highly influenced by intensive agricultural activities and urban areas. Two systematic sampling approach campaigns were implemented with six sampling points along the stream of the headwater catchment to evaluate water quality during the rainy and dry seasons. Three replicates were collected at each sampling point in 2011. Electrical conductivity, nitrates, nitrites, sodium superoxide, Chemical Oxygen Demand (DQO), colour, turbidity, suspended solids, soluble solids and total solids were measured. Water quality parameters differed among sampling points, being lower at the headwater sampling point (0m above sea level), and then progressively higher until the last downstream sampling point (2500m above sea level). For the dry season, the mean discharge was 39.5ls⁻¹ (from April to September) whereas 113.0ls⁻¹ were averaged during the rainy season (from October to March). In addition, significant temporal and spatial differences were observed (P<0.05) for the fourteen parameters during the rainy and dry period. The study enhance significant relationships among land use and water quality and its temporal effect, showing seasonal differences between the land use and water quality connection, highlighting the importance of multiple spatial and temporal scales for understanding the impacts of human activities on catchment ecosystem services.