Aseptic soil samples from the loam cover of a state highway shoulder in southeastern Massachusetts were placed in sterile serum bottles, forming a series of aerobic soil microcosms. The samples were dosed with reagent grade acetate solutions without acclimation, then sacrificed at various time intervals and analyzed by gas chromatography in a laboratory determination of the aerobic microbial degradation kinetics. The acetate degraded rapidly in the loam layer, demonstrating that the shoulder has the potential to reduce oxygen demand by acetate on groundwater under the highway.