Jet Grout Barrier Wall Completed!
Focus Shifts to Operable Unit 2

Operable Unit 1 (40 Willow Avenue)
National Grid and NYSDEC Reached a Major Milestone on the Final Major Phase of Remediation of OU-1 (40 Willow Ave. Sector) of Former Manufactured Gas Plant (MGP) Site.

The New York State Department of Environmental Conservation (NYSDEC) and National Grid (formerly KeySpan) have completed the installation of the jet grout barrier wall at the sector of the former manufactured gas plant site on which the gas holder and supporting facilities were located (the OU-1, 40 Willow Avenue parcel).  Quality assurance coring and hydrogeologic testing of select areas of the barrier wall have been completed, and the four walls have been certified by the Engineer-of-Record.  All site restoration activities have been completed and the jet grout and waste management contractors have demobilized from the site.

Field activities to monitor and study the potential for removing Dense Non-Aqueous Phase Liquid (DNAPL) from within the containment barrier were initiated in December 2009.  Pilot wells were placed within the holder foundation, adjacent to the former holder to evaluate soils just below the bottom of the holder foundation, and within coarse grained soils located at significant depths outside of the holder.  The next step is to perform a short-term recoverability test and analyze the results.  The following bullet points detail ongoing and future anticipated activities on the OU-1 site.
 
On-going activities:

Future (two week look-ahead) activities:

Recently Completed Activities:

Operable Unit 2 (25 Willow Avenue)

With the completion of the OU-1 barrier wall installation, focus has shifted to the remedial design investigation and remedial construction of OU-2.    OU-2 is the site of the former manufactured gas plant that previously operated at 25 Willow Avenue and was closed in 1957.  There also are two off-site areas that are located adjacent to OU-2 at 89 Willow Avenue and 1 Edgewater Street.  The remedial activities at OU-2 have progressed with the approval of the final remedial design work plan by NYSDEC and NYSDOH, including activities to be conducted during the Preliminary Design Investigation (PDI).  The PDI activities are conducted to provide additional design related data. PDI activities were initiated in December and consist of utility preclearance, geophysical and land surveys, drilling, test pit excavation, groundwater sample collection throughout the OU-2 properties.

Ongoing activities:

Future (two week look-ahead) activities:

Recently Completed Activities:

Community Air Monitoring Plan Summary

Operable Unit 1 (40 Willow Avenue)

A Community Air Monitoring Plan (CAMP) is implemented when intrusive activities are performed at Operable Unit 1.  However, there were no intrusive activities at OU-1 during the month of January that required CAMP monitoring. Copies of previous weekly CAMP reports and other site documents for OU-1 are stored at the two public document repositories for the project.