Horizontal and vertical transport in a multilayered aquifer of the Triassic sandstone, UK – tracer tests and modeling.

[摘要] The aim of the work was the quantification of horizontal and vertical solute transport of possible contaminants in the close vicinity (<10m) around pumped wells in conurbations. The Birmingham Triassic Sandstone aquifer was chosen to build a borehole array of five wells in the Wildmoor Sandstone. The five wells of the test site at the University of Birmingham approached seven sandstone layers, separated by six mudstone layers, approved with geophysical well logging. Specifically constructed packers were used to process tests quantifying the hydraulic and solute transport characteristics. Hydraulic conductivities between 1.27 m/d and 11.37 m/d were calculated with data of 14 pumping tests. Storage coefficients between 1.76x10-5 and 1.32x10-5 were determined. Average linear velocities of six sandstones were determined between 0.156 to 3.28m/d. Corresponding hydraulic gradients of 0.033 to 0.288 with up-flow in wells were calculated. Horizontal forced gradient tracer tests, being processed in three aquifers, recovered between 48% to 97% rhodamine WT and fluorescein. Effective porosity values between 0.00225 and 0.346 were calculated. A new setup of vertical forced gradient tracer tests, exploring the connectivity between two sandstone layers separated by a mudstone layer, was processed. Groundwater modelling was carried out to quantify especially dispersivity values for sandstone and mudstone layers. The tests give a full set of quantified hydraulic data for Triassic Sandstone to estimate contaminate transport within the area of pumped wells. The importance of fractures for the groundwater flow and contaminant transport in Triassic Sandstone, were confirmed by the tests.

[发布机构] University:University of Birmingham;Department:School of Geography, Earth and Environmental Sciences

[关键词] T Technology;T Technology (General)