Davis Mine was the largest working pyrite mine in the state of Massachusetts during its lifetime between 1882 and 1911. Since abandonment, a highly-polluting mine water discharge has emerged from the site of an old mine shaft and a waste rock pile and is contaminating the nearby Davis Mine Brook. During the past 90 years, no attempt has been made to implement any pollution abatement measures. This paper assesses the likely current volume of mine waste on the site and compares this figure with the amount of mine waste produced during the lifetime of the mine based on old mine plans and production figures. A simple mass balance model allowed us to compute the loadings of contaminants into Davis Mine Brook and to calculate the ratio of loadings from different sources of pollution, namely the mine shaft discharge and ground water discharge from the waste pile. Results for 2004 indicated that the proportion of mine water flowing from the shaft varies seasonally, with the greatest discharge in spring and lowest in summer. These results allow us to assess the potential lifetime of the discharge if left untreated and determine what flow pathways are important if a treatment scheme were to be implemented at the site.

Reprinted with Permission from Springer's Open Choice