Bay Shore Works MGP website, 2015

Substantial remediation progress has been made since major construction began in 2007 to support the cleanup activities in Bay Shore. Since October 2012, National Grid conducted or continued remedial activities at all four of the site's operable units. Although cleanup is not complete, contaminant levels for BTEX and PAHs are down sharply throughout the site, and this trend is expected to continue. All major construction is complete. The work entailed excavation of source areas to ~16-25 ft based on field conditions; removal and off-site thermal desorption of contaminated soil; in situ chemical oxidation using ozone to treat residual contamination beneath the excavated areas; installation of a subsurface barrier wall at the downgradient edge of OU-1 with in situ groundwater treatment immediately upgradient of the barrier; recovery of mobile water gas tar and DNAPL via extraction wells where practicable; and extensive use of oxygen injection to enhance bioremediation. See the Bay Shore Works website for project reports and other information, including progress videos: http://www.bayshoreworksmgp.com/.