After the Suffolk County Department of Health Services (SCDHS) detected high concentrations of MTBE in a Hampton Bays well, EAR was contracted to investigate the extent and fate of the MTBE contamination. Due to the innovative investigation and remedial approached adopted at the Hampton Bays site, it was recently used as a demonstration site for the joint NYSDEC–ITRC–LIGRI workshop entitled, “MTBE and TBA Comprehensive Site Assessment and Successful Groundwater Remediation.” EAR has also been awarded the esteemed 2004 National Ground Water Association (NGWA) Outstanding Groundwater Remediation Award for this project.
EAR performed an accelerated site assessment procedure (ASAP) using direct push methods, guided in the field by MTBE and TBA analysis results obtained from their on-site mobile laboratory. After evaluating the ASAP results, EAR installed a vast, three dimensional monitoring network to further delineate the contamination and provide future sampling locations. The ASAP results showed that a mixed fuel oxygenate plume, including methyl tert-butyl ether (MTBE) and its degradation product, tert-butyl alcohol (TBA), extended over 2,500 feet towards the Tiana Bay. Based on the results of EAR’s ASAP investigation and modeling, the NYSDEC requested the installation of an Interim Remedial Measure (IRM) to prevent further impact to the Tiana Bay.
For the IRM, EAR designed and constructed a large, innovative, sequential air-stripping bio-augmented granulated activated carbon (bio-GAC) treatment train, capable of removing the existing high concentrations of both MTBE and TBA at high flow rates and across the range of temperatures experienced at the site.
EAR also collaborated with the SCDHS and the Cornell Co-operative extension of Suffolk County (CCESC) to assist in determining the impact to Tiana Bay. On a barge operated by the SCDHS and using direct-push methods, numerous temporary sampling points were installed to document lithologic conditions and to determine the distribution of the fuel oxygenates under the Tiana Bay. Using the targeted discharge area, pore water geochemical, temperature and resistivity profiles were generated to further refine the fresh water discharge zone. Subsequently, ultrasonic seepage meters were installed in the bay sediments on the areas of discharge to quantify the specific discharge.
