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 that 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. 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. Weighting and standardizing values allows the relative extent of the pollution to be quantified simply, still within the framework of the permitted limits for the public water supply, while the proposed graphical representation makes it significantly easier to understand the phenomenon and proves useful for comparing temporal or spatial variations over the course of a river.
Keywords: acid mine drainage, drinking water, heavy metals