ABSTRACTThis study investigated the biodegradation of benzene, toluene, and the isomers of xylene (BTX) in anaerobic batch microcosms containing shallow aquifer material. BTX loss occurred with the addition of either nitrate or oxygen. Denitrification was confirmed by nitrous oxide accumulation after acetylene blockage of nitrate reductase. When a limiting amount of nitrate was added, there was a corresponding limit to the loss of BTX and a limited amount of nitrous oxide production. We propose that the addition of nitrate to gasoline‐contaminated aquifers would serve as an adjunct to current remedial technique