MCHM Degradation Data Release

This USGS data release includes all the data presented in peer-reviewed publication entitled "Degradation of MCHM (4-methylcyclohexanemethanol) in Sediments from Elk River, West Virginia". We conducted experiments on crude MCHM to examine photooxidation or biodegradation. We also assessed the potential of sediments to serve as a long-term source of MCHM and well as the potential for native microbial communities to catalyze the anaerobic breakdown of MCHM. We developed a quantitative method to measure the 2 isomers (cis- and trans-) of 4-MCHM, using solid phase micro-extraction (SPME), which had a minimum detection limit of 5 µg/L. The data release shows that the abiotic degradation experiments showed no evidence of photooxidation or abiotic degradation over 35-days for either MCHM isomer. Experiments with sterilized Elk River sediments showed sorption within 2 weeks, with 31% of trans-4-MCHM and 17.5% of cis-4-MCHM lost from solution. Impacted sediments from the spill site released substantial concentrations of trans-4-MCHM (up to 40 µg/L) and minor amounts of cis-4-MCHM (at the detection limit ~ 4 µg/L) into the overlying water solution after sterilization, indicating that sediments retained MCHM 10 months after the spill. In anoxic microcosms, 300 µg/L cis- and 150 µg/L trans-4-MCHM degraded to non-detectable levels in 8-13 days in both impacted and background sediments coupled to iron and sulfate reduction. MCHM degraded to non-detectable levels within 4 days under aerobic conditions. Microbial communities at impacted sites differed in composition compared to background and were less affected by MCHM amendments. Our results to date indicate that MCHM is readily biodegradable under environmentally relevant conditions.