Former General Motors North Tarrytown (Sleepy Hollow) Assembly Plant Site No. C360070

NYSDEC Finalizes the Former General Motors North Tarrytown Decision Document and Remedial Work Plan

Following the comment period, that was originally held from February 15, 2012 to March 30, 2012, and that was extended 30-days to April 29, 2012, and a public meeting held on March 22, 2012, the NYSDEC finalized the Decision Document and approved the Remedial Work Plan for the Former General Motors North Tarrytown Site on June 8, 2012. The Decision Document describes the remedy for the site and can be downloaded by selecting the link included below.

Former General Motors links:

Decision Document - Former General Motors North Tarrytown (PDF) (26 page, 2.1MB) - June 2012
Former General Motors Assembly Plant Site Draft Remedial Work Plan (PDF) (50 Page, 5 MB) - January 2012.
Fact Sheet - Remedy Proposed for Brownfield Site Contamination, Former General Motors North Tarrytown (PDF) (6 page, 400 KB) - February 2012

2007 Interim Remedial Measures (IRM) Decision Documents

IRM Decision Document (PDF) (20 page, 80 KB)
Figures 1 - 4 (PDF) (5 page, 1079 KB)
Figures 5 - 10 (PDF) (6 page, 972 KB)
Figures 11 - 15 (PDF) (5 page, 754 KB)
Figures 16 - 17 (PDF) (2 page, 337 KB)
Table 1 (PDF) (5 page, 548 KB)
Tables 2 - 4 (PDF) (5 page, 313 KB)
Responsiveness Summary (PDF) (33 page, 270 KB)

IRM Construction Completion Report

Hard copies of the IRM Construction Completion Report (September 2008) have been placed in the document repositories listed below. Copies of this electronic document are available upon request to Jason Pelton (888-459-8667).

Remedial Investigation Complete

Historical Overview

The site is located along the eastern shore of the Hudson River, occupies approximately 96.5 acres and is bisected by an active passenger and freight rail corridor. The site is the location of a former automobile assembly plant owned and operated by General Motors Corporation since 1914. At the time GM ceased assembly operations in July 1996, the main site features included two large manufacturing buildings. The assembly plant and support buildings were decommissioned and all structures have been demolished, except for two large floor slabs (covering much of the surface area on the west side of the railroad tracks) and a section of a pedestrian bridge over the rail lines.

The current proposal for the development of the West Parcel includes a mixed-use waterfront project with residential units, retail space, office space, an inn, the possibility for an on-site train station (subject to Metro-North approvals) and associated parking, with approximately 30 acres planned as publicly accessible open space.

The possible future uses of the East Parcel could include: the expansion of Devries Park; construction of a new Village Department of Public Works facility; and the expansion of adjacent Philipsburg Manor Restoration.

Project Activities to Date

In November, 2002, General Motors ("GM") and Roseland Property Company ("Roseland") entered into a Voluntary Cleanup Agreement ("VCA") with NYSDEC to investigate and remediate the site property for the purpose of post-remedial development for restricted residential and restricted commercial use ("Lighthouse Landing"). In March, 2005, GM/Roseland completed their transition to the Brownfield Cleanup Program ("BCP"). The Brownfield Cleanup Agreement was subsequently updated in 2010 to name GM LLC as a participant in the Brownfield Cleanup Program. A number of investigations/corrective measures have been performed by GM since 1996. Specifically, investigations identified subsurface soils and groundwater contaminated with lead, chromium, TCE and petroleum related constituents in four separate potential areas of concern (PAOC) at the site. The following remedial actions were taken in 2007 as part of Interim Remedial Measures (IRMs) to address these four areas of the site:

PAOC-7: Excavation and off-site disposal of 3,700 yd³ of soil;
PAOC-29: Excavation and off-site disposal of 1,100 yd³ of soil;
PAOC-47: Excavation and off-site disposal of 3,700 yd³ of soil and injection of 40,500 gallons of an in-situ chemical oxidant; and
Former Underground Storage Tank Area: Excavation and off-site disposal of 6,500 yd³ of soil along with the injection of an in-situ chemical oxidant.

Pre-excavation delineation sampling along with post-injection groundwater sampling data indicates that these IRMs have removed the contaminant source areas. A site-wide remedial approach involving engineering and institutional controls (EC/ICs) will be used to prevent public contact with soils and historic fill materials that contain low levels of remaining site contaminants exceeding SCGs. Specifically, the EC/ICs will prevent runoff of contaminated soil, minimize precipitation from infiltrating through residual contamination, mitigate intrusion of soil vapors and methane into indoor air spaces in future buildings, monitor groundwater in natural attenuation zones, and provide a mechanism to manage and mitigate possible short term exposure to subsurface materials during construction activities.

Remedial Investigation

Remedial Investigation activities were initiated at the site in the fall of 2003. Separate remedial investigations were completed for the on-site areas (West and East Parcels) and the off-site area (Hudson River). A draft Sediment Evaluation Report was submitted to the Department which presents off-site investigation information. Based on the findings of the previous sediment sampling program, it was determined that additional samples in the Hudson River needed to be collected. Work plans were developed (September 2006) with the additional sampling completed in October 2006. The results of the additional Hudson River sampling and analysis have been summarized in a Final Sediment Remedial Investigation Report (January 2012). The Department approved Sediment Remedial Investigation Report in January 2012.

The land-based Remedial Investigation Report was also finalized in January 2012 and placed in the document repositories. The Final Remedial Investigation Report presents findings for on-site investigations (East and West Parcels). As summarized in Remedial Activities to Date above, based on the results of the Remedial Investigation, IRMs were completed at the site in 2007 to address four areas of concern. The IRM activities are summarized in a Construction Completion Report dated September 2008.

Based on the remedial investigations (RI) along with interim remedial measures (IRMs) performed to date, the NYSDEC determined that the Former General Motors North Tarrytown Assembly Plant Site (site) does not present a significant threat to human health or the environment in September 2011.

Development of Cleanup Alternatives

With completion of the remedial investigations, cleanup options were evaluated for both the land-based portion of the site and the sediment-based portion of the site in documents called Alternatives Analysis Reports (AARs). The land-based and sediment based AARs have been placed in the document repositories for public review. Based on the evaluation of cleanup options in the AARs, the preferred remedy was subsequently outlined in the Remedial Work Plan prepared by GM and the Proposed Decision Document prepared by the NYSDEC. Both the Remedial Work Plan and the Proposed Decision Document have been placed in the document repositories and can also be downloaded by selecting the links included above. The NYSDEC will present the preferred cleanup option for the site at the March 22, 2012 public meeting.

The public is encouraged to review the project documents, which are available at the following repositories:

Warner Library
121 North Broadway
Tarrytown, NY 10591
Phone: (914) 631-7734
Hours: Monday and Thursday 1:00 p.m. - 9:00 p.m.
Tuesday and Wednesday 10:00 a.m. - 6:00 p.m.
Friday 9:00 a.m.- 5:00 p.m.
Saturday 10:00 a.m. - 5:00 p.m.
Sunday 1:00 p.m. - 5:00 p.m.

Sleepy Hollow Village Hall
28 Beekman Avenue
Sleepy Hollow, NY 10591
Phone: (914) 366-5106 (Village Clerk's Office)

NYS Department of Environmental Conservation
Region 3 Office
21 South Putt Corners Road
New Paltz, NY 12561-1696
Attn: Michael Knipfing
Phone: (845) 256-3154
Hours: Monday - Friday 8:30 a.m. - 4:45 p.m.

NYS Department of Environmental Conservation
Central Office
625 Broadway, 12th Floor
Albany, NY 12233-7013
Attn: Jason Pelton
Phone: (888) 459-8667
Hours: Monday - Friday 8:30 a.m. - 4:45 p.m.

Additional Information

Should you have questions regarding the status of the BCP project, at this site, you may contact:

Jason Pelton
Project Manager
NYS Department of Environmental Conservation
625 Broadway
Albany, New York 12233-7013
Phone: (888) 459-8667

For health related questions, you may contact:

Fay Navratil
NYS Department of Health
547 River Street
Troy, NY 12180
Phone: (800) 458-1158, Ext. 27880