Large-scale natural gradient tracer test in sand and gravel, Cape Cod, Massachusetts: 1. Experimental design and observed tracer movement

Denis R. LeBlanc; Stephen P. Garabedian; Kathryn M. Hess; Lynn W. Gelhar; Richard D. Quadri; Kenneth G. Stollenwerk; Warren W. Wood

doi:10.1029/91wr00241

USGS · 70185491

Large-scale natural gradient tracer test in sand and gravel, Cape Cod, Massachusetts: 1. Experimental design and observed tracer movement

Denis R. LeBlanc·Stephen P. Garabedian·Kathryn M. Hess·Lynn W. Gelhar·Richard D. Quadri·Kenneth G. Stollenwerk·Warren W. Wood

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Abstract

A large-scale natural gradient tracer experiment was conducted on Cape Cod, Massachusetts, to examine the transport and dispersion of solutes in a sand and gravel aquifer. The nonreactive tracer, bromide, and the reactive tracers, lithium and molybdate, were injected as a pulse in July 1985 and monitored in three dimensions as they moved as far as 280 m down-gradient through an array of multilevel samplers. The bromide cloud moved horizontally at a rate of 0.42 m per day. It also moved downward about 4 m because of density-induced sinking early in the test and accretion of areal recharge from precipitation. After 200 m of transport, the bromide cloud had spread more than 80 m in the direction of flow, but was only 14 m wide and 4–6 m thick. The lithium and molybdate clouds followed the same path as the bromide cloud, but their rates of movement were retarded about 50% relative to bromide movement because of sorption onto the sediments.

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Water Resources Research Article

Source-reported bounding extent: 41.60774162535756° to 41.703165313736655° latitude; -70.58303833007812° to -70.46905517578125° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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Denis R. LeBlanc, Stephen P. Garabedian, Kathryn M. Hess, Lynn W. Gelhar, Richard D. Quadri, Kenneth G. Stollenwerk, Warren W. Wood. 2008-01-08. Large-scale natural gradient tracer test in sand and gravel, Cape Cod, Massachusetts: 1. Experimental design and observed tracer movement. https://doi.org/10.1029/91wr00241

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