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Unisys Corporation Site - Lake Success

Site Number: 130045

Remedy Proposed for State Superfund Site

Public Comment Period and Public Meeting Announced

Public Meeting, Thursday, 6/26/2014 at 7:00 PM
Great Neck South Middle School
349 Lakeville Road, Great Neck, NY 11020

NYSDEC invites you to a public meeting to discuss the remedies proposed for the site. You are encouraged to provide comments at the meeting, and during the 30-day comment period - June 13 through July 14, 2014.

The public is invited to comment on the amendment to the 1997 Record of Decision (ROD) proposed for the onsite remedy (operable unit or OU 1) and a new remedy proposed for the offsite contamination (OU 2) related to the Unisys Corporation site ("site") located at 1111 Marcus Avenue, Lake Success, Nassau County. Please see the map for the site location.


Additional documents related to the cleanup of this site can be found at the location(s) identified below under "Where to Find Information."

How to Comment

NYSDEC is accepting written comments about the proposed plans for 30 days, from June 13, 2014 through July 14, 2014. Please submit comments to the NYSDEC project manager listed under Project Related Questions in the "Who to Contact" area below.

The site is listed as a Class "2" site in the State Registry of Inactive Hazardous Waste Sites (list of State Superfund sites). A Class 2 site represents a significant threat to public health or the environment; action is required.

Proposed Actions

ROD amendment for OU1: An amendment is proposed to the onsite ROD which includes the following modifications or additions to the original remedy:

  1. Modification to the original pumping rate identified in the original ROD based on the remedial design. This change has already been implemented.
  2. Identification of the subslab depressurization systems installed to preclude the intrusion of chemical vapors into the existing buildings and a provision to evaluate vapor intrusion in the construction of new buildings.
  3. Imposition of an institutional control in the form of an Environmental Easement which requires:
    • Restricting the use of the site property to commercial use except for the area used as a soccer field which will be restricted residential use (which also allows for active recreational uses).
    • Prohibits the installation of onsite potable wells without the necessary treatment
    • Development of a Site Management Plan approved by the Department.
    • Periodic Certification that the Engineering and Institutional Controls are in place and operating.

Proposed Remedial Action Plan (PRAP) for OU2: The remedy proposed for the offsite groundwater contamination that has migrated from the site includes:

  1. The continued operation of the existing 500 gallons per minute (gpm) OU2 Interim Remedial Measure (IRM) groundwater extraction and treatment system located at the Great Neck School property.
  2. Upgrade of the current 730 gpm OU1 groundwater remediation system by the installation of a new 120 gpm extraction well to collect and treat an additional volume of groundwater bringing the total system up to 850 gpm.
  3. Implementation of a Public Water Supply Protection and Mitigation Program which includes:
    • an installation, operation and maintenance plan for public water supply wellhead treatment systems on wells affected by site-related contamination, now or in the future, to assure that drinking water standards are achieved;
    • a response plan that will be implemented if site-related contaminant concentration(s) in the sentinel well(s) approach or exceed site-specific action levels.
  4. Development of a Site Management Plan approved by the Department and operation of a treatment system on the Lake Success irrigation well should it be used again.
Additional Details

In 2003, Environmental Conservation Law (ECL) was amended to require the placement of an Environmental Easement on all class 2 inactive hazardous waste disposal sites that rely on institutional controls as part of the remedy selected for the site. Further, the promulgation of the regulations necessitated by the change in ECL redefined operation, maintenance and monitoring activities as Site Management and set forth requirements for a Site Management Plan as the mechanism for assuring the institutional and engineering controls for a site were in place and effective to support the restrictions on the site imposed by the Environmental Easement. These new requirements are effective for all RODs issued after the ECL changes in 2003.

In 2006, New York State embarked on a proactive approach relative to vapor intrusion which is the movement of chemical vapors from a subsurface source into the indoor air of overlying structures. This is called the Vapor intrusion Legacy effort. NYSDEC evaluated all inactive hazardous waste disposal sites where a remedy had been selected prior to 2003 to determine if there was the potential for vapor intrusion. The Unisys site was evaluated as part of this effort which identified the potential for vapor intrusion and a mitigation system determined necessary and installed. The requirement for installation and operation of this system is proposed to be included in the amended ROD.

The off-site IRM to address OU2 groundwater at the Great Neck School District property previously completed during the RI is incorporated into this PRAP for consideration as part of the site remedy. This IRM includes a groundwater recovery well and treatment system installed on the Great Neck School District property. The system consists of an extraction well screened at various depths, two air strippers, an air emission control and three injection/diffusion wells located east of and adjacent to Great Neck School District property. The OU2 groundwater IRM system has been extracting contaminated groundwater, treating it and reinjecting the clean groundwater back into the aquifer at a rate of 500 gallons per minute since 2006.

Summary of the OU2 Investigation

Based upon investigation conducted at the site, the primary site-related contaminants of concern for the site groundwater are volatile organic compounds: cis-1,2 dichloroethene, trichloroethene, tetrachloroethene and 1,1,2-Trichloro-1,2,2-Triflouroethane (Freon 113). The groundwater plume originating from the nearby 400 Lakeville Road site (Site No. 130176), known to contain Freon 22, commingles with the Unisys site groundwater plume.

Groundwater migration from onsite has resulted in a significant off-site groundwater plume which has impacted both the Upper Glacial and Magothy aquifers. The lower Lloyd aquifer has not been affected. The groundwater flow direction is to the northwest. The groundwater plume has impacted Public Supply Wells and Golf Course Irrigation Wells in the area. Several of these Public Supply Wells in the plume area have treatment systems in place so the water supplied meets acceptable drinking water quality. People are not drinking the contaminated groundwater because municipal water suppliers have taken appropriate actions (such as treating the groundwater to remove contaminants prior to distribution or removing wells from service) to ensure that the public water supply continues to meet drinking water standards.

No site-related constituents were detected in the water or sediment in Lake Success or the irrigation pond (Lake Surprise). The groundwater plume, below the bottom of both Lake Success and Lake Surprise, has not affected either lake, and is not expected to affect these lakes in the future. Potential exposure to contaminated groundwater via irrigation well usage to air (via volatilization) was evaluated at a golf course and no impacts were identified

As part of the Vapor Intrusion Legacy effort, the potential for vapor intrusion in the former manufacturing facility was identified. This resulted in the installation of an active sub-slab depressurization system (SSDS) in two buildings, and a passive SSDS in one building.

Next Steps

NYSDEC will consider public comments as it finalizes the remedies for the site. The selected remedies will be described in documents called an "Amended Record of Decision" and a "Record of Decision" for the onsite and offsite areas, respectively. The RODs will explain why the remedies were selected and respond to public comments. A detailed design of the selected remedies will then be prepared, and the cleanup will be performed.

NYSDEC will keep the public informed throughout the investigation and cleanup of the site.


Site Location: The former Unisys Site is located in the Village of Lake Success and the Town of North Hempstead, Nassau County. The site is bounded by Marcus Avenue to the north, Union Turnpike to the south, Lakeville Road to the west and the Triad Office Park to the east.

Site Features: The site is approximately 94 acres in area. The former Unisys property is fully developed, with the bulk of the property comprised of the main manufacturing building, various smaller support buildings (e.g., foundry and boiler building), three recharge basins, and parking lots. The smaller buildings are located south of the main building. The site was redeveloped by the current owner for commercial use. Presently, the buildings house a number of tenants. The current site owner has deeded 3.5 acres of the property in the southeast corner to the Town of North Hempstead for their use as soccer fields.

Current Zoning/Use(s): The site straddles the border of the Village of Lake Success and the Town of North Hempstead. The portion of the property in the Village of Lake Success is zoned Economic Development A (commercial). The portion of the property in the Town of North Hempstead, including the soccer fields, is zoned Industrial A. The off-site area (OU2) is mixed residential/commercial/industrial.

Past Use of the Site: The former Unisys facility was an active manufacturing facility from its start-up in 1941 until approximately 1995, when most manufacturing activities ceased, although some assembly, integration, prototype development/testing, and/or engineering and administrative activities continued at the facility through early 1999. The facility has been served by a sanitary sewer system since it was constructed in 1941. The on-site storm water collection system which received runoff from the parking lot, roofs and surrounding roads is connected to the three recharge basins located in the southwest corner of the property. Groundwater had been used for non-contact cooling purposes since the facility was constructed. The non-contact cooling water system consisted of three extraction wells and four diffusion wells which were located to the north and south of the main manufacturing building, respectively. The groundwater is no longer used for cooling purposes. In the past, the facility manufactured a wide range of defense related products. Past manufacturing processes included casting, etching, degreasing, plating, machining and assembly. Chemicals used during manufacturing at the facility included halogenated solvents, cutting oils, paints and fuel oils and plating compounds. The facility had five drywells located off the southeastern corner of the main building. These drywells were used to dispose of water containing solvents and oils from approximately 1941 to 1978.

Operable Units: The site was divided into two Operable Units to facilitate remediation. An operable unit represents a portion of the site remedy that, for technical or administrative reasons, can be addressed separately to eliminate or mitigate a release, threat of release or exposure pathway resulting from the site contamination.

Operable Unit 1 (OU1) consists of the 94 acre site property. A Record of Decision (ROD) was issued for OU1 in March 1997.

Operable Unit 2 (OU2) is defined as the off-site area beyond the 94 acre property where contaminants in groundwater have migrated from the site (OU1). Eleven active public supply wells are located within OU2, nine drawing from the Magothy aquifer, and two drawing from the Lloyd aquifer. Four inactive public supply wells are located within OU2, as are six active irrigation wells.

Geology/Hydrogeology: The site and surrounding area is underlain by unconsolidated surficial deposits with an estimated 700 foot thickness, and Precambrian bedrock below. The unconsolidated deposits are comprised of the following formations from the ground surface downward: Upper Glacial deposits (150 ft); Magothy formation (250 ft); Raritan Upper Clay unit (200 feet); Raritan Lloyd Sand unit (190 feet) and bedrock.

The groundwater flow in the area has been divided into four zones: the Upper Glacial aquifer and the upper, middle, and basal portions of the Magothy aquifer. The depth to groundwater is approximately 100 feet below ground surface. Generally, the groundwater flow direction is north/northwest. However, pumping by several public supply/irrigation wells in the area affects the groundwater flow direction.

Additional site details, including environmental and health assessment summaries, are available on NYSDEC's Environmental Site Database.

State Superfund Program: New York's State Superfund Program (SSF) identifies and characterizes suspected inactive hazardous waste disposal sites. Sites that pose a significant threat to public health and/or the environment go through a process of investigation, evaluation, cleanup and monitoring. More information about the SSF.

For More Information

Where to Find Information
Project documents are available at the following location(s) to help the public stay informed.

Great Neck Public Library
Attn: Ms. Laura Weir
159 Bayview Avenue
Great Neck, NY 11023
phone: 516-466-8055

Hillside Public Library
Attn: Ms. Charlene Noll
155 Lakeville Road
New Hyde Park, NY 11040
phone: 516-355-7850

Project Related Questions
Girish Desai
Department of Environmental Conservation
Division of Environmental Remediation
SUNY at Stony Brook 50 Circle Road
Stony Brook, NY 11790-3409

Site-Related Health Questions
Renata Ockerby
New York State Department of Health
Corning Tower, Room 1787
Empire State Plaza
Albany, NY 12237

Site Location

Unisys Superfund Site location map on Long Island
Location of Unisys State Superfund Site in Lake Success, NY.

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