LACK OF CORRELATION BETWEEN ORGANIC-ACID CONCENTRATIONS AND PREDOMINANT ELECTRON-ACCEPTING PROCESSES IN A CONTAMINATED AQUIFER

Long-term (1992-1995) monitoring data from a petroleum hydrocarbon-con taminated aquifer were used to examine the hypothesis that concentrati ons of low molecular weight (LMW) aliphatic organic acids reflect term inal electron-accepting processes. During the period of study, concent rations of dissolved hydrogen (H-2) indicated that methanogenic, sulfa te-reducing, and iron(III)-reducing conditions predominated at the sit e. However, there was no correlation between LMW organic acid concentr ations and concentrations of dissolved H-2. These results indicate tha t organic acid concentrations are not a reliable indicator of local re dox conditions at this site.