Monthly Update, November - December 2010

As of November 2010, National Grid has completed the installation work for oxygen delivery system #2, located from Mirschel Park to Kensington Court. The oxygenation system is operating and treating the groundwater plume associated with the Hempstead former Manufactured Gas Plant (MGP) Site by accelerating the rate of natural bioremediation within the groundwater plume.  Please see the attached figure showing the location of the treatment systems. 

During November, National Grid started the installation of a similar oxygenation system (System #1) along Smith Street, the inactive LIRR right of way and a short section along Hilton Ave.  This system will require approximately three to four months for installation.  As with the first system, a drill rig is being used to install oxygen wells and excavating equipment is being used for digging piping trenches. 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. After all of the work is done, the areas will be fully restored.

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.

National Grid has also started the procurement process to obtain bids for remediating the residual MGP materials located at the former site itself, and under the parking lot immediately to the south of the MGP Site.  This soil remediation work is the largest phase of the remediation project, and will use solidification with cement and other additives to encapsulate the MGP residuals in these areas.  The bidding process is expected to be completed in early 2011, and work is expected to commence on this soil remediation phase of the program in the Spring of 2011. 
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

Thank you for your cooperation as we continue to make progress addressing the environmental issues associated with the Hempstead former Manufactured Gas Plant Site.