This article describes the method used to quantify the Environmental Impact for the mining, by drilling and blasting, of a borrow pit for a gravity-dam. The affected environment was broken down into a number of components, such as public health and safety, social relationship, air and water quality, flora and fauna. The effect of the various impacting factors from the mining activities, both directly and indirectly, was then calculated for each environmental component. To do this, each impacting factor was first given a magnitude, a number based solely on the range of scenarios possible for the impacting factor. A matrix of weighting factors was then derived to systematically quantify, and normalise, the effects of each impacting factor on each environmental component. The overall impact upon each individual environmental component was then calculated by summing the weighted magnitudes for all the impacting factors. The method, which is outlined here in a schematic form, was originally developed for a mining operation in Sardinia, Italy. It has subsequently been successfully used for trough and other mining ventures and more general industrial activities, such as waste dumping, recycling and, energy production. As with any evaluation, the method requires an element of subjective assessment but it does at least give transparency to the process used to assess environmental impact. The method can be used to ensure the consistency of approach required to allow realistic comparisons to be made between various design solutions, mitigation measures. In a wider sphere, for instance a provincial mining district it could be used to ensure a consistent means of comparison between the environmental impacts due to different mining sites.