Zimmerman, B. | 2018 Long-Term Stewardship Conference, 20-24 August, Grand Junction, CO, 17 slides, 2018

In June 1995, EPA approved the Record of Decision for the Operable Unit 1 (OU 1) area of the Mound Site in Ohio that encompassed a historical waste disposal landfill. The original remedy for controlling contamination in OU 1 was the collection, treatment, and disposal of groundwater through a pump and treatment (P&T) system. Results from investigative field studies indicated that the cleanup timeframe for the P&T remedy was projected to require an additional 26 years, whereas enhanced attenuation (EA) had a projected cleanup timeframe of 13 years. EPA approved an EA field demonstration and the P&T system was placed on standby. In 2014, DOE initiated a multi-year field demonstration to evaluate whether EA could expedite the remediation of PCE, TCE, and daughter products detected in the groundwater. The field demonstration was initially scheduled to operate for three years but impacts from an off-site dewatering operation and regional drought conditions during the second year caused perturbation in data trends. As a result, the field demonstration was extended to include a fourth year. Nearing completion of its final year, the field demonstration indicates the OU 1 groundwater system has recovered from the effects of the lowered groundwater levels and increased hydraulic gradients experienced during the second year. Results from the third year of the field demonstration indicate the dissolved PCE and TCE plumes continue to decrease in size and mass. https://www.energy.gov/sites/prod/files/2018/10/f56/Zimmerman-Expediting-Groundwater-Remediation.pdf See the EA Sampling and Analysis Plan https://www.lm.doe.gov/cercla/documents/mound_docs/AR/2104XXXXXX-1410240003.pdf Also see https://www.energy.gov/em/articles/innovative-approach-cuts-cleanup-time-half-potentially-saving-6-million