About Bay Shore Former MGP Site

Cleanup Progress

Substantial progress has been made since major construction began in 2007 to support the cleanup activities in Bay Shore, specifically in OU-1. Through October 2015, National Grid has completed or continued remediation activities at all four of the Operable Units which make up the site. The cleanup of this site is not yet complete, but contaminant levels have decreased sharply throughout the area, and with recent upgrades to the existing systems, this trend is expected to continue.

The site has been divided into four separate areas called Operable Units (OU-1 through OU-4). Each OU includes a specific portion of the project area.

Major cleanup activities in OUs 1, 2, 3 and 4 have been completed. In 2015, National Grid upgraded the 87 Community Road oxygen injection line and expanded the OU-1 South oxygen injection line across N. Clinton Avenue. The work is intended to target remaining downgradient localized groundwater impacts.

OU-3 is at the western end of the site. A large fuel storage tank and associated piping once stood in this area, containing a kerosene-like petroleum product that was used as the feedstock for the gas manufacturing process. Several other, smaller tanks were also present. OU-3 is defined to include the “Brightwaters Yard” portion of the original plant site west of North Clinton Ave., and the plume of contaminated groundwater which originated in this area and previously extended southward as a narrowband in the vicinity of Lanier Lane.

As was the case with OU-1 and OU-2, the cleanup strategy in OU-3 has been to remove as much of the contaminated source material as possible from the original MGP plant site, and to introduce oxygen into the groundwater to encourage soil bacteria to consume the contaminants that have already dissolved in groundwater and migrated beyond the site boundaries.

Contaminated soil in the Brightwaters yard was removed during several rounds of excavation. The most recent effort, in 2010, included temporary relocation of the LIRR tracks adjacent to the site to allow excavation of contaminated soil below the tracks.

A line of oxygen injection wells, similar to those in OU-2, was installed along the south side of Union Boulevard in 2000. This system was replaced in 2010 with a new system located on the north side of Community Road. An area of high groundwater contaminant concentrations was present in the area between the 2010 LIRR excavation and the new oxygen injection line. In response, National Grid upgraded the new Community Road injection system in 2012 and installed an additional oxygen injection system in August 2013 upgradient (north) of the Community Road system and south of the LIRR to accelerate the destruction of groundwater contamination in this area.

This system was effective in significantly reducing groundwater impacts in this area. However, residual impacts have been identified north of this system under the LIRR property. In order to expedite the elimination of groundwater impacts in this area, modifications to the oxygen injection system north of Community Road to facilitate the installation of additional oxygen injection wells on the LIRR property, were implemented in June 2015.

Contaminant levels south of Union Boulevard have declined sharply. Groundwater impacts at concentrations above drinking water criteria have not been detected downgradient of Union Boulevard in OU-3 since the second quarter of 2014.

A small area of shallow groundwater contamination was identified near the intersection of Lanier Lane and Cooper Lane in early 2013. A detailed investigation was performed to determine the scope of the problem. It appears that the installation of an upgraded basement dewatering system was drawing more heavily impacted groundwater upward from the deeper plume. In response, National Grid installed a treatment system to remove contaminants from the water being produced by the basement pumping system. The initial treatment system was upgraded in October 2013 to a system designed to handle the fluctuating flow rates produced by the basement pumping system.

Under direction from NYSDEC, National Grid also initiated a more direct strategy for increasing oxygen levels in the surrounding groundwater beneath the property. To expedite the treatment, a series of 21 slurry-injection points were installed surrounding the small contaminated area in March 2013. These points serve the same purpose as the oxygen gas injection wells, but they are a one-time application that is much simpler and quicker to implement. The slurry consists of a chemical compound which slowly dissolves and releases oxygen over a time period of several months. Monthly groundwater data indicate that these efforts were successful in treating the small area of groundwater impacts in this area.

A second round of slurry injections was performed in August 2013 upgradient of the previous application to address a small area of impacts north of the property. Groundwater analytical data indicate that the combination of the operation of the upgradient oxygen injection systems and the oxygen release compound (ORC) injections were successful in eliminating groundwater impacts downgradient of Union Boulevard in OU-3.

Groundwater analytical data and sump discharge water analytical data indicate that there have been no impacts in the vicinity of this property since April 2014. The treatment system was removed from the property in February 2015. A final round of slurry injection was performed in January 2015 in the vicinity of this property prior to system removal.

Numerous project milestones have been reached since KeySpan (now National Grid) entered into an order on consent with NYSDEC in 1999.

Timeline of Project Milestones

1999 2000
  • KeySpan (now National Grid) and NYSDEC enter into an order on consent
  • Smith Avenue remediation work begins
  • Brightwaters Yard remediation work
  • Field work for remedial investigation planned
  • First public meeting (January)
  • Watchogue Creek/Crum's Brook interim remedial measure (IRM) field work
  • Brightwaters Yard chemical oxygen injections
2001 2002
  • Planning for supplemental remedial investigation
  • OU-3 chemical oxidation injections in the Brightwaters Yard
  • Supplemental remedial investigation
  • OU-3 underground storage tank excavation and chemical oxidation injections
2003 2004
  • Final remedial investigation report
  • Remedial action plan and record of decision for OU-1
  • OU-3 soil removal takes place under a temporary movable fabric enclosure
  • OU-3 additional chemical oxidation injections
  • OU-3 installation of the Brightwaters Yard oxygen injection system
  • OU-4 background soil sampling
2005 2006
  • OU-2 oxygen system installations begin
  • OU-1 testing for sheet wall installation
  • OU-4 excavation of hot spots of contaminated soil in Cesspool Area
  • First quarterly Operations, Monitoring and Maintenance (OM&M) report
  • Excavation IRM in south cell of OU-1 paves way for full excavation
  • Requested indoor air monitoring of OU-2 residences begins
2007 2008
  • Installation of OU-1 barrier wall
  • Excavation of OU-1 begins
  • Launch of Bay Shore project website
  • OU-1 barrier wall completed
  • OU-1 shallow and deep excavation program completed
  • Three additional oxygen injection lines planned and installed in OU-2
  • Storm drain rehabilitation project was completed in OU-3
  • http://bayshoreworksmgp.com/ is re-launched
2009 2010
  • An additional oxygen injection system installed at the tail end of OU-2.
  • Cooper Lane line extended
  • LIRR tracks relocated and excavation of contaminated soils began in OU-3
  • In-Situ chemical oxidation injections performed in the cesspool portion of OU-4
  • OU-1 Groundwater treatment facility completed and activated
  • Areas west of barrier wall in OU-1 investigated and remediated, two additional oxygen lines installed
  • OU-3 excavations under LIRR tracks and in the Brightwaters Yard completed, tracks restored
  • Installation of Community Road oxygen injection line and abandonment of Union Boulevard oxygen injection system.
2011 2012
  • OU-2 installation of one additional and an extension of an existing oxygen injection system
  • OU-3 post LIRR excavation groundwater evaluation conducted
  • OU-4 excavation of MGP impacts, backfilling and restoration completed
  • OU-3 post LIRR excavation groundwater evaluation completed
  • OU-3 upgrade of Community Road oxygen injection line completed
  • OU-4 restoration of site following excavation activities completed
  • OU-4 post remediation sampling of Watchogue Creek sediment and surface water completed
  • OU-1 investigative work on adjacent property completed
2013 2014
  • OU-1 additional recovery well installed to remove additional coal tar from within the barrier wall
  • OU-3 installation of 21 oxygen releasing compound (ORC) points to remediate a small area of shallow contamination near the corner of Lanier and Cooper Lanes completed
  • OU-3 planned remediation of area of shallow contamination south of the Long Island Railroad tracks and north of Community Road” to “OU-3 installation and start-up of oxygen injection system on 87 Community Road
  • OU-1/OU-2 installation of oxygen injection slurry injection points to remediate a shallow groundwater in area along Union Boulevard, just west of North Clinton Avenue
  • OU-1 installation of one additional and an extension of an existing oxygen injection system
  • OU-3 Additional Injection of Oxygen Release Compound (ORC) near the corner of Lanier and Cooper Lanes
  • OU-1 expansion of the existing oxygen injection system to address shallow groundwater contamination beneath N. Clinton Avenue
  • OU-3 Additional Injection of Oxygen Release Compound (ORC) near the corner of Lanier and Cooper Lanes
  • OU-3 expansion of 87 Community Road oxygen injection systems to include injection wells in the Long Island Rail Road right-of-way

View the Progress

Total BTEX

Click on the image above to view an animation of the reduction of TBTEX from 2008 to 2015.

Total PAH

Click on the image above to view an animation of the reduction of TPAH from 2008 to 2015.

The Bay Shore/ Brightwaters cleanup is entering its final phase and groundwater monitoring and operation, maintenance and monitoring (OM&M) activities are in place in all OUs to measure the effectiveness of cleanup activities and ensure their ongoing performance.