Rapid method of field for preliminary characterization of contaminant capacity for waters in AMD sources

Abstract

Council directive 98/83/CE of 3 November 1998 on the quality of water intended for human consumption, defines the minimum requirements that must be met by continental surface waters intended for human consumption, for all member countries in the European Community, restricting the use of such waters based on their composition. The occurrence of AMD phenomena in rivers which contribute their waters to dams intended for urban supply leads to waters arriving in these reservoirs with low pH and a high metal and sulfate load, as in the case of the rivers Cobica and Odiel in SW Spain. The aim of this work is to formulate a rapid method for finding out the degree of water pollution in the field, based on the toxicity produced by sulfates and metals dissolved in solution, using simple pH measurement in rivers which undergo AMD processes and which flow into public water supply dams. A classification model based on the degree of the impact is proposed, which is applied to a river affected by AMD in the Iberian Pyritic Belt, and which might serve as a reference for other dams that have to tolerate the arrival of mine water. The present work involves a modification of the Gray proposal and also places its “water-quality ratings” within the limits of European guidelines. Application of the proposed method will allow the approximate state of the water quality to be learned by simply measuring its pH. This may prove very useful during the design of hydrochemical control networks.