Monthly Update, March 2010

During March, National Grid selected a contractor 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.  The Contractor is currently preparing construction documents for this work, and installation activities related to the system located near Mirschel Park are expected to start in April 2010.

The pre-design investigation for the in-situ solidification (ISS) remediation phase of the Remedial Action Plan was completed in 2009, and NYSDEC has approved this document which is included in the key documents section of this web site.  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 471 gallons of MGP tar have been recovered 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.