U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting Charleston South Carolina March 8-12, 1999--Volume 3 of 3--Subsurface Contamination From Point Sources, Water-Resources Investigations Report 99-4018C

Computer Simulation of Fluid Flow in Fractured Rocks at the Mirror Lake FSE Well Field

ABSTRACT

A numerical finite-difference model is developed to simulate fluid flow in the fractured rock underlying the FSE well field at the U.S. Geological Survey Fractured Rock Research Site near Mirror Lake, New Hampshire. Highly transmissive fracture clusters in the bedrock are represented by model cells of comparatively higher hydraulic conductivity. The surrounding bedrock containing less transmissive fractures is represented by model cells of comparatively lower hydraulic conductivity. The model is calibrated to drawdown data from a multiple-well hydraulic test. Calibration results suggest that the highly transmissive fracture clusters are three to four orders of magnitude more conductive than the surrounding bedrock with less transmissive fractures. Relatively good matches between simulated and observed drawdowns suggest that a heterogeneous continuum model can be applied to simulate fluid flow in the fractured rock underlying the FSE well field.