The February 2007 edition of the Quarterly Journal of Engineering Geology and Hydrogeology included a paper entitled Migration of polluted mine water in a public supply aquifer. I make bold as to repeat the abstract.

Following the cessation of dewatering in the southern part of the Durham Coalfields in 1974, groundwater levels rose in both the mine workings and the overlying Magnesian Limestone Aquifer (MLA). A pollution plume has since been migrating through the MLA with sulfate concentrations greatly exceeding potable water standards. Prediction of future plume development requires specification of whether upflow of mine water to the MLA occurs from a small number of point sources or in a diffuse manner (i.e., distributed over most of the area in which the MLA is underlain by mineworkings.) A program of conceptual and numerical modeling has addressed this issue. Mine plans and geological information were used to characterize the flooded mine system and its interface with the MLA. Piezometric and metereological data were used to constrain finite difference simulations of groundwater flow in the MLA. Flow velocity vectors derived from these flow simulations allowed modeling of plume migration by solution of the advection-dispersion equation. The results of these simulations illustrate that it is necessary to invoke both point and diffuse upflow to explain the observed patterns of pollutant migration to 2003. Predictive modeling of further plume migration indicates that sulfate concentrations are likely to rise to unacceptable levels in the most proximal public supply wells within the next two decades.

For those interested, they used MODFLOW for flow calculations and MT3D for solute transport simulations. The paper is, in my opinion, well written, readable, logical, and informative. Except for the sad conclusion: “Model results from a simulation carried out for further development of the sulfate plume indicate that further down-gradient expansion of the plume is inevitable, eventually rendering some current public supply wells unusable (at least without blending with other waters,) unless some preventative intervention is made.”

The full text can be purchased for US$30.00. Not worth it unless your company pays and charges some unsuspecting client.