This metadata record presents analytical results for laboratory microcosms conducted during 2016–18 as part of a study to develop a field test and numerical interpretation method to determine the effective diffusion coefficients and sorption coefficients of trichloroethene (TCE) and daughter products in the rock matrix of sedimentary rock, as well as biodegradation rate coefficients in the borehole. The biodegradation rate coefficients in the borehole are an important component of defining the back-diffusion of TCE from the matrix of sedimentary rock. Microcosm experiments were conducted with microbial community samples and groundwater collected from boreholes in the field test area to define anaerobic biodegradation rates of TCE and trichlorofluoroethene, a reactive analog for TCE that was used in the field tracer tests. Included in the dataset are (1) a description of the treatments for 6 sets of microcosm experiments that were conducted, (2) volatile organic compound concentrations measured in water from the 6 sets of microcosm experiments, (3) volatile organic compound concentrations measured in select sediment samples from one microcosm experiment, and (4) dissolved gases and iron concentrations measured in select sets of microcosm experiments.