The state Department of Environmental Conservation (DEC) has denied Suffolk County's request for further study of the Bay Shore plume site.

As News 12 has previously reported, an old LILCO fuel processing plant left potentially cancer-causing contaminants in the groundwater. National Grid and the DEC have been cleaning up the site and testing the water for years.

County officials now say that cleanup efforts may have caused even more toxins, known as oxy PAHS, to leak into the ground. They want to assess the impact of the contaminants on the soil and ground water, and make sure there was no impact on the county's sole source aquifer.