A forced-gradient test of solute transport was conducted adjacent to the site of a previous natural gradient test to allow comparison of results obtained from the two types of field tests. In the forced-gradient test, one inorganic tracer and four organic solutes (carbon tetrachloride, trichloroethylene, tetrachloroethylene, and hexachloroethane) were injected for 48 hours. The migration of the dissolved chemicals toward the extraction well was monitored by multilevel samplers and a partially penetrating monitoring well. Moment analyses of the solute breakthrough curves at the multilevel points provide model-independent insight into the variation of hydraulic conductivity and organic solute retardation in the aquifer. The estimated retardation factors fall within the range estimated in the previous natural gradient test. Sorption distribution coefficients inferred from the transport data indicate spatial variability of sorption for all solutes, with mean values and ranges similar to those observed in laboratory studies of core or bulk samples. Some evidence was obtained for spatially variable in situ transformation of hexachloroethane.