註釋 This article aims at presenting the results of the "Survey of Industrial Water Use at the Paraiba do Sul River Basin". This survey collected data about 488 industrial facilities located in the river basin area. The survey had the following goals: a) providing a general characterization of the role of water in industrial plants; and b) assessing the financial and environmental impacts of the implementation of water charges in the basin, through the analysis of firms' water demand behaviour and effluent treatment costs. Results suggest that water charges may attain satisfactory results in terms of water resources conservation while not implying in significant cost increases to the firms. On the other hand, marginal treatment cost estimations are far above the proposed charge levels for effluent discharge. This indicates that, at least during the initial implementation period, water charges will not be an effective mechanism to induce firms to undertake pollution control measures. 