National Grid to Begin Groundwater Treatment System Installation Work
 Between Mirschel Park and Kensington Court

 Project intended to remediate groundwater related to the Hempstead MGP Site

 Temporary inconvenience possible for certain walkways, driveways and traffic lanes  

National Grid is planning to begin the installation of the underground oxygen delivery system from Mirschel Park to Kensington Court to treat the underground groundwater plume associated with the Hempstead former Manufactured Gas Plant (MGP) Site.  The oxygenation system will accelerate the rate of natural bioremediation within the groundwater plume. The wells and oxygen lines will be installed in Mirschel Park, on private property at 158 Hilton Avenue, along the right-of-way on the east side of Hilton Avenue, and on the south side of Kensington Court.  Please see the attached figure showing the location of the treatment systems.

The first part of the work starting in early April includes some additional groundwater sampling along Kensington Court and along Hilton Avenue before the system installation.  The installation of the oxygenation system will include excavating two to three feet deep trenches where the oxygen lines will be placed, and drilling the wells to deliver the oxygen to the underground groundwater plume. The oxygen lines will be connected to an oxygen generator that will be located at 158 Hilton Avenue.

When the installation of the oxygen system begins, excavating equipment will be used for digging piping trenches in Mirschel Park and in the road right-of-ways. Small diameter wells will be drilled in pre-determined locations and oxygen injection lines will be placed into the trenches and connected to the wells. Based on the completed environmental investigations in the area, the shallow soils to be excavated are not contaminated from the former MGP Site.  Each day, after wells and lines are installed, the trenches will be secured. The trenching and installation of the wells for this system should take approximately 3 months, depending on the weather. After all of the work is done, the areas will be fully restored.  

All of the work will be conducted with oversight from the New York State Department of Environmental Conservation, the New York State Department of Health, and the Nassau County Department of Health.

Should you have any questions or concerns about the work, please use National Grid’s Hempstead Intersection Street Project Hotline at 516 545 6161.  Additional information about the investigation and remediation of the Hempstead Intersection Street former MGP Site is also available on the project website at www.hempsteadintersectionstreetmgpsite.com
                             
Thank you for your cooperation as we continue to make progress addressing the environmental issues associated with the Hempstead former Manufactured Gas Plant Site.