Monthly Update, February 2010

During February, National Grid evaluated Contractor bids for installing the groundwater treatment systems that are one phase of the three-phase Remedial Action Plan (interim remedial measures, groundwater treatment and in situ solidification) selected by the New York State Department of Environmental Conservation for the site.  Two groundwater treatment systems will be installed. One system will be located between Smith Street and Hilton Avenue, and the other will be located between Mirschel Park and Kensington Court (see the figure contained in the November 2009 Fact Sheet and in the Key Documents section of this web site).  Each groundwater treatment system will include an oxygen generating equipment building enclosure, oxygen delivery wells, and underground piping connecting the equipment enclosure and wells.  National Grid is currently evaluating the bids and will award a contract for the work.  Installation of the systems is expected to start in the March-April 2010 timeframe pending receipt of property access agreements.   

The pre-design investigation for the in-situ solidification (ISS) remediation phase of the Remedial Action Plan was completed in 2009.  Additional soil borings were drilled at the site in the summer of 2009 to further refine the extent of contaminated soil in certain areas.  An updated pre-design investigation report was issued to the NYSDEC for review in February 2010.  Engineering design for the ISS remediation is scheduled to be completed during the first half of 2010 and National Grid will solicit construction bids after completing the ISS design. 

On-going activities at the Hempstead Intersection Street former MGP Site include bimonthly monitoring and recovery of MGP tar from site related wells including the six (6) additional MGP tar recovery wells that were installed in the summer of 2009.  Approximately 460 gallons of MGP tar have been collected since April, 2007.  Groundwater samples are collected and analyzed quarterly to monitor the concentration and extent of the plume.  The groundwater monitoring data indicates that the plume remains stable over time due to documented natural biodegradation.