2011-20587. National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List: Deletion of the Pasley Solvents & Chemicals, Inc. Superfund Site

AGENCY:

Environmental Protection Agency.

ACTION:

Direct final rule.

SUMMARY:

The Environmental Protection Agency (EPA) Region 2 is publishing a direct final Notice of Deletion of the Pasley Solvents & Chemicals, Inc Superfund Site (Site), located in the Town of Hempstead, Nassau County, New York, from the National Priorities List (NPL). The NPL, promulgated pursuant to section 105 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, as amended, is an appendix of the National Oil and Hazardous Substances Pollution Contingency Plan (NCP). This direct final deletion is being published by EPA with the concurrence of the State of New York, through the New York State Department of Environmental Conservation (NYSDEC), because EPA has determined that all appropriate response actions under CERCLA have been completed. However, this deletion does not preclude future actions under Superfund.

DATES:

This direct final deletion is effective September 26, 2011 unless EPA receives adverse comments by September 12, 2011. If adverse comments are received, EPA will publish a timely withdrawal of the direct final deletion in the Federal Register informing the public that the deletion will not take effect.

ADDRESSES:

Submit your comments, identified by Docket ID no. EPA-HQ-SFUND-1986-0005, by one of the following methods:

• Web site: http://www.regulations.gov. Follow on-line instructions for submitting comments.
• E-mail: [e-mail].
• Fax: To the attention of Sherrel Henry at 212-637-3966.
• Mail: Sherrel Henry, Remedial Project Manager, U.S. Environmental Protection Agency, Region 2, 290 Broadway, 20th Floor, New York, New York 10007-1866.
• Hand delivery: Superfund Records Center, 290 Broadway, 18th Floor, New York, NY 10007-1866 (telephone: [phone]). Such deliveries are only accepted during the Docket's normal hours of operation, and special arrangements should be made for deliveries of boxed information.

Instructions: Direct your comments to Docket ID no. EPA-HQ-SFUND-1986-0005. EPA's policy is that all comments received will be included in the public docket without change and may be made available online at http://www.regulations.gov,, including any personal information provided, unless the comment includes information claimed to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Do not submit information that you consider to be CBI or otherwise protected through http://www.regulations.gov or e-mail. The http://www.regulations.gov Web site is an “anonymous access” system, which means EPA will not know your identity or contact information unless you provide it in the body of your comment. If you send an e-mail comment directly to EPA without going through http://www.regulations.gov,, your e-mail address will be automatically captured and included as part of the comment that is placed in the public docket and made available on the Internet. If you submit an electronic comment, EPA recommends that you include your name and other contact information in the body of your comment and with any disk or CD-ROM you submit. If EPA cannot read your comment due to technical difficulties and cannot contact you for clarification, EPA may not be able to consider your comment. Electronic files should avoid the use of special characters, any form of encryption, and be free of any defects or viruses.

Docket

All documents in the docket are listed in the http://www.regulations.gov index. Although listed in the index, some information is not publicly available, e.g., CBI or other information whose disclosure is restricted by statue. Certain other material, such as copyrighted material, will be publicly available only in the hard copy. Publicly available docket materials are available either electronically in http://www.regulations.gov or in hard copy at: U.S. Environmental Protection Agency, Region 2, Superfund Records Center, 290 Broadway, 18th Floor, New York, NY 10007-1866.

Phone: [phone].

Hours: Monday to Friday from 9 a.m. to 5 a.m.

Information for the Site is also available for viewing at the Site Administrative Record Repositories located at: Levittown Library, 1 Bluegrass Lane, Levittown, New York 11756. Tel. [phone].

Hours: Monday through Friday: 9 a.m. through 9 p.m., Saturday: 9 a.m. through 5 p.m.

FOR FURTHER INFORMATION CONTACT:

Sherrel D. Henry, Remedial Project Manager, U.S. Environmental Protection Agency, Region 2, 290 Broadway, 20th Floor, New York, NY 10007-1866, [phone], by e-mail at [e-mail].

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Introduction

II. NPL Deletion Criteria

III. Deletion Procedures

IV. Basis for Site Deletion

V. Deletion Action

I. Introduction

EPA Region 2 is publishing this direct final Notice of Deletion of the Pasley Solvents & Chemicals, Inc Superfund Site (Site), from the National Priorities List (NPL). The NPL constitutes Appendix B of 40 CFR part 300, which is the National Oil and Hazardous Substances Pollution Contingency Plan (NCP), which EPA promulgated pursuant to section 105 of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) of 1980, as amended. EPA maintains the NPL as the list of sites that appear to present a significant risk to public health, welfare, or the environment. Sites on the NPL may be the subject of remedial actions financed by the Hazardous Substance Superfund (Fund). As described in 300.425(e)(3) of the NCP, sites deleted from the NPL remain eligible for Fund-financed remedial actions if future conditions warrant such actions.

Because EPA considers this action to be noncontroversial and routine, this action will be effective September 26, 2011 unless EPA receives adverse comments by September 12, 2011. Along with this direct final Notice of Deletion, EPA is co-publishing a Notice of Intent to Delete in the “Proposed Rules” section of the Federal Register. If adverse comments are received within the 30-day public comment period on this deletion action, EPA will publish a timely withdrawal of this direct final Notice of Deletion before the effective date of the deletion, and the deletion will not take effect. EPA will, as appropriate, prepare a response to comments and continue with the deletion process on the basis of the Notice of Intent to Delete and the comments already received. There will be no additional opportunity to comment.

Section II of this document explains the criteria for deleting sites from the NPL. Section III discusses procedures that EPA is using for this action. Section IV discusses the Pasley Solvents & Chemicals, Inc Superfund Site and demonstrates how it meets the deletion criteria. Section V discusses EPA's action to delete the Site from the NPL unless adverse comments are received during the public comment period.

II. NPL Deletion Criteria

The NCP establishes the criteria that EPA uses to delete sites from the NPL. In accordance with 40 CFR 300.425(e), sites may be deleted from the NPL where no further response is appropriate. In making such a determination pursuant to 40 CFR 300.425(e), EPA will consider, in consultation with the state, whether any of the following criteria have been met:

i. Responsible parties or other persons have implemented all appropriate response actions required;

ii. All appropriate Fund-financed response under CERCLA has been implemented, and no further response action by responsible parties is appropriate; or

iii. The remedial investigation has shown that the release poses no significant threat to public health or the environment and, therefore, the taking of remedial measures is not appropriate.

III. Deletion Procedures

The following procedures apply to deletion of the Site:

(1) EPA consulted with the State of New York prior to developing this direct final Notice of Deletion and the Notice of Intent to Delete co-published today in the “Proposed Rules” section of the Federal Register.

(2) EPA has provided the State 30 working days for review of this notice and the parallel Notice of Intent to Delete prior to their publication today, and the State, through the NYSDEC, has concurred on the deletion of the Site from the NPL.

(3) Concurrently with the publication of this direct final Notice of Deletion, a notice of the availability of the parallel Notice of Intent to Delete is being published in a major local newspaper, Anton News (Three Village Times and the Floral Park Dispatch). The newspaper notice announces the 30-day public comment period concerning the Notice of Intent to Delete the Site from the NPL.

(4) The EPA placed copies of documents supporting the proposed deletion in the deletion docket and made these items available for public inspection and copying at the Site information repositories identified above.

(5) If adverse comments are received within the 30-day public comment period on this deletion action, EPA will publish a timely notice of withdrawal of this direct final Notice of Deletion before its effective date and will prepare a response to comments and continue with the deletion process on the basis of the Notice of Intent to Delete and the comments already received.

Deletion of a site from the NPL does not itself create, alter, or revoke any individual's rights or obligations. Deletion of a site from the NPL does not in any way alter EPA's right to take enforcement actions, as appropriate. The NPL is designed primarily for informational purposes and to assist EPA management. Section 300.425(e)(3) of the NCP states that the deletion of a site from the NPL does not preclude eligibility for future response actions, should future conditions warrant such actions.

IV. Basis for Site Deletion

The following information provides EPA's rationale for deleting the Site from the NPL:

Site Background and History

The Site, EPA ID No. NYD991292004, is located in the Town of Hempstead in Nassau County, New York. The Site property measures 75 feet by 275 feet with a fenced boundary on the north, east and south sides and is located at 565 Commercial Avenue, Town of Hempstead, Nassau County, New York. The Site lies between the borders of the political subdivisions of the Village of Garden City and Uniondale, in the Town of Hempstead. A building and loading platform form the western boundary of the Site at the adjacent property.

From 1969 until 1982, the Site was occupied by the Pasley Solvents and Chemicals Company (Pasley) and was used as a chemical distribution facility. Activities at the Site included delivery and storage of chemicals in tanks on-site, and transfer of the chemicals to 55-gallon drums for delivery to customers. Some customers reportedly returned used chemicals and empty drums to the Site. These chemicals included a wide range of aromatics and halogenated aliphatic hydrocarbons, solvents, ketones and alcohols. Commander Oil Corporation (Commander) owned the Site prior to 1969 when the Site was used by Commander for distribution of fuel oils.

In 1980, Pasley applied for a New York State Department of Environmental Conservation (NYSDEC) permit to store and remove chemicals. The Nassau County Department of Health (NCDOH) collected soil samples from the Site. Analyses of the samples indicated that the soils were contaminated with volatile organic compounds (VOCs). In 1980, NCDOH referred the Site to NYSDEC and both agencies recommended that Pasley submit a plan for a remedial investigation and cleanup. In 1981, Lakeland Engineering performed a limited well drilling and ground water sampling program. Five on-property and one off-property monitoring ground water wells were installed and ground water samples were collected by Lakeland and the New York State Department of Health (NYSDOH). Contaminants were detected above State drinking water standards.

The Site was proposed to the NPL in October 1984 (49 FR 40320) and was listed on the NPL in June 1986 (51 FR 21054).

After all remedial action at the site was completed; Plato Holding LLC bought the property from Commander in August 2003 and concluded negotiations with the Metropolitan Transit Authority (MTA) to utilize the Site as a police station. In 2004, the Site was paved and an office trailer was placed on concrete blocks. Plato Holding sold the property to Yonah Reality in March 2007. It is Yonah Reality's intent to continue to use the property as a police station.

Remedial Investigation and Feasibility Study (RI/FS)

On August 19, 1988, EPA and Commander entered into an Administrative Order on Consent, Index NO. II-CERCLA-80212 (the Order). The Order required Commander to perform a Remedial Investigation/Feasibility Study (RI/FS) to determine the nature and extent of contamination at the Site, to develop and analyze cleanup alternatives and to remove the 12 above-ground storage tanks located on the Site. In November of 1988, Commander completed the tank removal. The RI was performed by Metcalf and Eddy, Inc. for Commander in 1990. During the RI subsurface soil samples, ground water samples and surface soil samples were collected and analyzed. As part of the ground water investigation eighteen ground water monitoring wells were installed. The monitoring wells were clustered in six locations (three wells each, screened at depths of 30, 60, and 90 feet). The ground water quality of the aquifer underlying the Site, downgradient and upgradient of the Site was assessed by two rounds of water quality sampling in 1990 and a third round of partial sampling in 1991. The most prevalent VOC detected in ground water during the RI was trans—1,2-dichloroethene at a maximum concentration of 37,000 parts per billion (ppb). Samples collected from upgradient off-site monitoring wells showed a maximum level of 27 ppb of tetrachloroethene (PCE) (monitoring well location MW-1S) and 15 ppb for trichloroethene (TCE) (monitoring well location MW-1D). Benzene was also detected at a maximum level of 38 ppb (monitoring well location MW-1l). Since a contaminant plume could not be defined by plotting the Total Volatile Organic Compounds (TVOCs) associated with the Site study area, a group of VOCs which were found at the Site but which were not detected in upgradient well cluster well MW-1 were chosen to define the plume associated with the Site (identified as Site Index Compounds (SICs)). Through the use of the index compounds, a well defined contaminant plume could be identified for the Site.

The SICs chosen to define the plume for the Site are the following: chloroform, 1,1dichloroethene, 1,1-dichloroethane, trans-1,2-dichloroethene, 1,1,1-trichloroethane, ethylbenzene, toluene, chlorobenzene, and xylene. The SICs were found to contribute a major part (99%) of the contamination found in the monitoring well cluster located on-site (MW-2). Non-site index compounds acetone, benzene, TCE and PCE, which were found in on-property wells and upgradient were also monitored. However, the use of SICs does not imply that non-index compounds are absent from the Site.

The SIC plume for the 20 to 30-foot depth Upper Glacial aquifer extended approximately 400 feet to the southwest, parallel to the ground water flow direction and the contaminant plume was approximately 390 feet wide. The maximum level of SIC contamination detected was 37,000 parts per billion (ppb) for trans-1,2-dichloroethene, 7400 times the Federal Maximum Contaminant Level (MCL) of 5 ppb. TCE, although not part of the SIC plume, was also detected at a maximum concentration of 320 ppb, 64 times its MCL of 5 ppb. The SIC plume for the 50 to 60 foot depth in the Lower Glacial aquifer was found to be much smaller, and centered on MW-4I, directly downgradient of the Site. The maximum level of SIC contamination in this portion of the plume was 15 ppb for trans-1,2-dichloroethene. TCE was also detected at 15 ppb. No SIC contamination was found directly downgradient or on-site in the 80 to 90 foot depth in the Upper Magothy aquifer.

Fifty (50) surface soil grab samples were collected and analyzed for VOCs. These samples were collected from an approximate 30-foot grid pattern at a depth of 6 to 12 inches below grade. Samples were then collected and composited for metals and semi-volatile organic analyses. Each composite sample consisted of soil from five adjacent discrete sample locations.

Data from the surface soil samples revealed elevated levels of VOCs originating from three primary locations. The concentrations of TVOCs, primarily PCE and trans-1,2-dichloroethene, were detected in concentrations of 1,000 ppb up to concentrations of 603,000 ppb. Additionally, total semi-volatile organic compounds were detected in composite samples collected from ten locations. The highest concentrations of total semi-volatiles were detected in composite samples 8 and 9 (204,000 ppb and 126,500 ppb, respectively) collected on the eastern edge of the Site.

Subsurface samples were also collected from eight locations on-site and five locations off-site. On-site, two samples were collected from each of eight borings at depths of 12 to 14 feet and 23 to 25 feet (or the first two feet below the water table). A total of sixteen samples were collected. Elevated levels of total VOCs (greater than 1,000 ppb) were detected in six of the sixteen samples.

Based on the results of the RI report, a risk assessment was performed for the Site. The risk assessment determined that although the risk posed by the soils are within EPA's acceptable risk criteria, contaminants in the soils, if not addressed, would continue to contribute to further contamination of the ground water, resulting in a potential future risk from ground water ingestion.

A FS was then completed to identify and evaluate remedial alternatives that would be effective and implementable in addressing the contamination, based on site-specific conditions. The FS Report was developed based on the “Guidance for conducting Remedial Investigation and Feasibility Studies under CERCLA.” Remedial alternatives were developed to satisfy the following Remedial Action Objectives (RAOs) for the Site:

• The soils will be treated until the soil cleanup objectives are met or until no more VOCs can be effectively removed from the unsaturated zone.
• Contaminated groundwater will be treated to meet either Federal or state groundwater standards except in those cases where upgradient concentrations are above such standards.

Selected Remedy

Based upon the results of the RI/FS, on April 24, 1992, a Record of Decision (ROD) was signed, selecting a remedy for the Site. The major components of the 1992 ROD included the following:

• Treatment of approximately thirteen thousand (13,000) cubic yards of contaminated soil by soil vacuuming (also referred to as soil vapor extraction), and/or by soil flushing;
• Disposal of treatment residuals at a RCRA Subtitle C facility;
• Remediation of the ground water by extraction/metals precipitation/air stripping with vapor phase granular activated carbon (GAC) polishing;
• Pumping of contaminated ground water from three extraction wells at a combined flow rate of approximately 450 gallons per minute;
• Implementation of a long-term monitoring program to track the migration and concentrations of the contaminants of concern; and
• Implementation of a monitoring program that would include the collection and analysis of the influent and effluent from the treatment systems.

After the ROD was issued, EPA sent notice letters and a draft Consent Decree (CD) to Commander and to the operators of the Site (Robert Pasley and Pasley Solvents and Chemicals Company) for implementation of the remedy selected in the ROD. These parties declined to perform the selected remedial action. Counsel for Commander contended that Commander was not financially able to implement the remedy which was estimated to cost 14 million dollars. As a result, in 1993 EPA obligated Superfund monies for performance of the remedial design (RD) by Ebasco Services, Inc., an EPA contractor.

Subsequently, Commander notified EPA that it believed that an innovative technology, air sparging modification to the ground water remedy would be an effective means to remediate the ground water, at approximately half the cost of the selected remedy. EPA evaluated all available information on the air sparging technology and gave approval for Commander to submit a work plan to conduct a pilot study to evaluate the effectiveness of air sparging at the Site. The results of the pilot study, which were documented in the Air Sparging (AS)/Soil Vapor Extraction (SVE) Pilot Test Study Report, demonstrated that air sparging would be an effective means of remediating the ground water at the Site.

As a result, EPA determined that AS was a viable technology in combination with SVE to clean up the ground water and soils at the Site and subsequently on May 22, 1995, EPA issued a ROD Amendment selecting the following remedy:

• Remediation of the ground water by AS in the contaminated saturated zone underlying the property;
• Remediation of the on-property unsaturated zone soils and collection of AS vapors by SVE;
• Interception and remediation of the off-property ground-water plume by AS accompanied by SVE in the area of Cluster Park, a local park located near the facility;
• Implementation of a long-term ground-water monitoring program to track the migration and concentrations of the contaminants of concern; and
• Implementation of a remediation system monitoring program that would include vapor monitoring, ground-water monitoring and soil sampling.

The ROD and ROD Amendment were intended to remediate the soil so that the Site property, which does not currently have permanent structures present, could be used without restriction. Therefore, no Institutional Controls (ICs) were required for the selected remedy at the Site.

Response Actions

In 1995, EPA concluded CD negotiations with the PRPs related to the performance of the remedial design, remedial construction, operation, maintenance, and monitoring of the remedy selected in the ROD Amendment. On January 26, 1996, the CD was entered in United States District Court (approved by the Judge) for the Eastern District of New York.

CRA Services was selected by Commander to design, construct, and operate the remedial system. EPA approved the RD in April 1997. Construction of the remedy started on June 26, 1997 and was completed on October 21, 1997. Construction activities are summarized in the Remedial Action Report, dated July 14, 1998. The Remedial Action Report documented that the work was performed in accordance with the approved design, consistent with the decision documents and that appropriate construction standards and QA/QC procedures were used.

The remediation system consisted of two SVE/AS systems: One on the Pasley property; and one off the Pasley property in Cluster Park. The system worked by introducing air into the aquifer to volatilize organic compounds and capture the organic vapors. The vapors from the on-property system were treated with GAC, prior to discharge. Rotary-vane AS compressors and rotary-lobe SVE blowers, housed in the on-property treatment building, were used to “push” and ”pull” the air and soil vapor from both systems.

Major components of the constructed remedy include:

On-Property

• 19 AS wells, 2-inch polyvinyl chloride (PVC), screened 50-52-feet below ground surface (bgs)
• Eight shallow SVE wells, 2-inch PVC, screened 5-10 feet bgs
• Eight deep SVE wells, 4-inch PVC, screened 15-20 feet bgs
• Five monitoring well clusters
• Buried piping to each AS/SVE well
• 24 x 24-ft treatment building
• AS and SVE blowers, piping and controls
• GAC vapor treatment system
• Condensate collection and GAC treatment system
• Re-infiltration gallery
• Off-property AS and SVE blowers, piping, controls

Off-Property

• Fifteen AS wells, 2-inch PVC, screened 50-52 feet bgs
• Five SVE wells, 2-inch PVC, screened 15-20 feet bgs
• Six monitoring well clusters
• Buried piping to each AS/SVE well
• Buried distribution vault and controls

The AS/SVE system operated from October 1997 to October 2002. The system was shut down when monitoring data indicated that groundwater and soil cleanup levels specified in the 1995 ROD had been met. The Notice of Completion and Final Operation and Maintenance (O&M) Report were submitted by Commander in 2003. In January 2004, post remediation monitoring began to ensure site related contamination had been effectively remediated.

Cleanup Goals

Consistent with the ROD and ROD Amendment, the site-specific ground water and soil cleanup goals are summarized in Table 1 below.

Table 1

Contaminant	Groundwater cleanup goal (μg/L) 1	Recommended soil cleanup goals (ppm) 2
Chloroform	7	0.3
1,1-Dichloroethene	5	0.4
1,1-Dichloroethane	5	0.2
Trans-1,2-Dichloroethene	5	0.3
1,1,1-Trichloroethane	5	0.8
Ethylbenzene	5	5.5
Toluene	5	1.5
Chlorobenzene	5	1.7
Xylene	5	1.2
Acetone	50	0.2
Benzene	0.7	0.06
Tetrachloroethene	5	1.4
Trichloroethene	5	0.7
VOCs (total)	N/A	10
1 Maximum Contaminants Levels (MCLs).
2 NYSDEC Technical and Administrative Guidance Memorandum (TAGM) 446: Determination of Soil Cleanup Objective and Cleanup Levels, Rev Jan 1994.

As stated in the RAO described above, contaminated groundwater was treated to meet either Federal or state groundwater standards (MCLs) except in those cases where upgradient concentrations are above such standards. The upgradient groundwater contaminants are acetone, TCE, benzene and PCE.

Soils

When the concentrations of vapors appeared to be stabilizing, soil sampling was conducted to assess remedial progress. The soil sampling was completed in July 2000. A total of 12 soil borings were taken at the Site. It should be noted that sampling took into account the three primary locations of elevated concentration identified in the RI. The samples submitted for analysis were taken from the interval with the highest detected concentration of VOCs (measured by a photo ionization detector (PID)) in each boring. The results indicated that an area near MW-2S (BH-12 area) required additional treatment. Contingency measures were implemented in order to decrease the concentrations of SICs (specifically xylene) below cleanup levels. Contingency measures included shutting off the east side air sparging wells and diverting air to the area around MW-2S. In addition, inorganic nutrients in the form of a commercial garden fertilizer (Miracid 30:10:10) were added to the west side well in an attempt to accelerate biological activity for further chemical reduction, and two more AS wells were installed in the area.

In April 2003, when system monitoring no longer detected VOCs in the west side wells, soil sampling was again conducted. This effort was focused in the area near MW-2S. The results showed concentrations below the cleanup objectives.

Groundwater

Four on-site ground water monitoring wells and seven down gradient monitoring wells were monitored over the 5-year SVE/AS operation period (from 1997 to 2002). A total of 19 rounds of ground water samples were taken during that period. Samples were analyzed for SICs as described above. In addition to the SICs, acetone, TCE, benzene and PCE were included in each analysis because they were also detected on-site. Collectively the SICs and these four other compounds were described as the total volatile organic index compounds (TVOICs). The use of SICs and TVOICs provided a means of ensuring that site related contamination was monitored and provided the ability to differentiate site related contamination from those up gradient contaminants believed to be moving through the site. Ground water monitoring was performed prior to the start of operation of the treatment system, during operation of the system and again during the Post Remediation Monitoring (PRM) phase. During each phase, the number of wells monitored and frequency of monitoring varied per the monitoring plans.

The soils at the Site were identified as a source of contamination to the ground water. Specific cleanup levels in soils were specified in the ROD Amendment. The remedial action objectives specified in the ROD were met as demonstrated in soil sample results taken in July 2000 and April 2003.

In order to demonstrate restoration of groundwater and soil contamination in the source area for site-related contamination, it was assumed that if SVE/AS effectively removed all source material, then concentrations down gradient of the first line of sparge wells would have similar concentrations of SICs and TVOICs during remediation and during PRM because all VOC contamination (both SIC and TVOICs) in the saturated zone would be addressed by the system. To evaluate this assumption, results from ground water monitoring wells in this area (MW-9724 and MW-9725), were compared based on concentrations of SICs and TVOICs over time.

As shown in Table 2 below, monitoring wells, MW-9724 and MW-9725 had comparable concentrations of SICs and TVOICs from February 2000 through May 2002 during active SVE/AS operation. Over this time, well MW-9724 had concentration of SICs in 2/2000 of 197 ppb and concentrations of TVOICs of 205 ppb. Samples taken in 5/2002 showed declines from the concentrations in 2/2000 to 0 ppb SICs and 1 ppb TVOIC. Further support is provided from evaluation of the data from well MW-9725 where the concentrations in 2/2000 of SIC were 356 ppb and the concentrations of TVOIC were 360 ppb. Declines were found in 5/2002 where the concentration of SIC was 9 ppb and for TVOIC was 10 ppb.

Table 2—Comparison of Well MW-9724 and MW-9725 Data to Demonstrate Consistency in Concentrations Between SICs and TVOIC

Time line	MW-9724 SIC concentrations	MW-9724 TVOIC concentrations	MW-9725 SIC concentrations	MW-9725 TVOIC concentrations
02/2000	197 ppb	205 ppb	356 ppb	360 ppb.
06/2001	7 ppb	12 ppb	107 ppb	109 ppb.
05/2002	0 ppb	1 ppb	9 ppb	10 ppb.

These results demonstrate that any source material in the saturated zone was addressed for both SICs and any site related TVOICs during system operation. This is further supported by the fact that confirmatory sampling of on-site soils showed that all contaminants had achieves the cleanup objectives specified in the ROD and ROD amendment.

Next, in order to verify the ROD Assumptions that upgradient contamination (particularly TCE and PCE) were present at the Site, pre-ROD, during the Remedial Action (RA), and Post RA, groundwater monitoring results during these three phases were reviewed and evaluated.

Pre-ROD Determination. The RI/FS documented TCE and PCE at concentrations of 15 ppb and 27 ppb, respectively in an upgradient well (MW-1). The levels of TCE and PCE fluctuated during the RI/FS. Sample results from other on-site wells indicated concentrations lower than those found in the upgradient well. Based on this finding, further investigations were conducted at other locations within this area (outside of the site boundaries, as defined) as described below.

The Roosevelt Field, a former airfield that is now a large shopping mall located approximately 2000 feet north of the Pasley site, was identified as a potential source of PCE and TCE at the Pasley site during the RI/FS. Investigations performed at the Roosevelt field site identified three volatile organic ground water contamination plumes of TCE and PCE. Two of the contamination plumes exist in the Upper Glacial aquifer, and the third is present in both the Upper Glacial aquifer and the Magothy Formation. The Upper Glacial aquifer plumes are at depths similar to the Pasley SIC plume. These plumes were reported in 1986 to extend at least 1,000 feet to the south southwest of Roosevelt Field, and within 400 feet of the Pasley Site. Specifically, the 1992 ROD Declaration of Statutory Determinations section stated that “Due to the existence of an upgradient source of contamination, the selected ground water remedy, by itself, will not meet chemical-specific ARARs nor be capable of restoring the area ground water to applicable ground water quality standards until these upgradient source areas are removed”.

During RA. Groundwater monitoring was conducted over the five year SVE/AS operation period at the Pasley site. The results of ground water monitoring during this period demonstrate the ROD assumption that up gradient contamination (particularly TCE and PCE) were present during RA. During the RA, MW-1I upgradient of the Site showed consistent elevated TVOIC concentrations. Between 1998 and 2001, TVOIC concentrations ranged from 9 to 204 ppb. SIC concentrations ranged from 2 to 32 ppb. Therefore, throughout the period of operation, TVOIC concentrations accounted for a majority of the contamination found during monitoring events. The consistently low presence of SICs indicate that site-related contamination did not impact this well. These results conclude that directly upgradient of the remediation system, VOC contamination was consistently flowing underneath the source area being remediated.

Prior to remediation the SICs represented 99% of the TVOICs present in MW-2S located on the western edge of the source area. Results for 13 of the next 15 sampling events (up until the 2002 sampling event) similarly showed the percentage of SICs as greater than 90% of the TVOICs present. These results contrasted significantly from those for the upgradient well MW-1I where the SICs represented less than 10% of the TVOICs in 6 of 8 sampling events clearly indicating that there was an upgradient source of non-site index compounds. However, by the time the remediation was complete, the percentage of SICs present in MW-2S was similar to that typically present in MW-1I (i.e., less than 10%) as the SICs concentration was reduced to 2 ppb and the TVOICs were present at 22 ppb. This data also indicates, at the end of remediation, even though SIC had been addressed, levels of other VOCs continued to be present. This data concludes that VOCs that were not site-related continued to impact the groundwater being remediated. See Table 3, below.

Table 3—Comparison of SIC and TVOIC Concentration Between On-Site Groundwater Monitoring Well MW-2S ³ and Upgradient Well MW-1I

Time Line	On-site wells		Upgradient wells
	MW-2S SIC concentrations (ppb)	Total MW-2S TVOIC concentrations (ppb)	MW-1I SIC concentrations (ppb)	MW-1I TVOIC concentrations (ppb)
1997—Prior to Start of RA	6914	7013	NA	NA
8/1998	1013	1046	2	101
8/2000	890	937	9	178
6/2001	328	335	8	183
5/2002	88	288	NA	NA
1/2004	2	22
8/2005 4	7	32	NA	NA
3 MW-2S—most contaminated on site ground water monitoring well.
4 Toluene was detected at elevated concentrations in all samples collected but was found to be a laboratory contaminant; therefore the values were not included.

The monitoring data for off-property monitoring wells also demonstrate the success of the remedy. Seven off-property wells, located approximately 400 feet down gradient of the Site, were monitored over the five-year O&M period. As described in the Remedial System Overview (above), four off-site monitoring wells (MW-9721, MW-9724, MW-9725, and MW-4S) were located upgradient of the SVE/AS off-site system. The three remaining wells (MW-9720, MW-9722, and MW-9723) were located downgradient of the SVE/AS off-site system.

Upgradient wells MW-9724, MW-9725, and MW-4S had levels of SICs and TVOICs that were elevated during the first three years of O&M. These elevated levels for both SICs and TVOICs were reduced once contaminant levels on-property were reduced by the on-site treatment efforts indicating that the system effectively addressed all VOC contamination within the treatment zone. In addition, the declining SIC concentrations indicate that no additional on-site source material in the saturated zone is contributing to the groundwater contamination downgradient of the source area SVE/AS system. Once remediation started, no SICs or TVOIC contamination was detected in monitoring wells down gradient of the off-site SVE/AS system (MW-9722 or MW-9723).

Two monitoring wells (MW-9720 and MW-9721) were located downgradient of the treatment systems but were located hydraulically sidegradient of the treatment area. It was assumed, if groundwater flowing on site was affected by upgradient sources, these wells would show fluctuating levels of TVOIC concentration but would not have SIC concentrations above cleanup levels. MW-9720 showed a fluctuation in TVOIC and no SICs readings throughout the entire 5 year operations monitoring period. In addition, monitoring well MW-9721 also showed consistent fluctuation in the TVOIC numbers and limited SICs numbers. The fluctuation in the TVOIC and the lack of SICs in monitoring wells (MW-9720 and MW-9721) indicate that the contamination detected was not originating from the Site.

These results indicate that the treatment system was effectively treating the contamination originating from the Site by the reduction of SIC concentration in the onsite monitoring well MW-2S and the downgradient monitoring wells (MW-9724, MW-9725, MW-4S, MW-9722 and MW-9723) to the cleanup levels indicated in the ROD. Finally, data from MW-2S in the source area, upgradient well MW-1I, and downgradient/sidegradient wells MW-9720 and MW-9721, show persistent TVOIC concentrations in both on-site, upgradient, and sidegradient wells during the operation period supporting the ROD assumption that PCE and TCE contamination were coming on site from upgradient sources.

During PRM. Prior to the start of the post remediation monitoring, the upgradient monitoring well (MW-1) located on private property was destroyed and could not be sampled. During PRM only one on-site monitoring well (MW-2S) and three downgradient monitoring wells (MW-9720, MW-9722, and MW-9723) were monitored. When evaluating the PRM data, it is important to note that the 2/9/2005 sampling event is an anomaly of high concentrations due to laboratory contamination. These results were not evaluated in this analysis.

During the first two PRM sampling rounds (January and July 2004), the analytical results for samples collected from MW-2S indicated that TCE and PCE and all SICs were at or below MCLs. However, in the next three sampling events in 2005, the concentrations of PCE increased above MCLs going to 22 ppb to 170 ppb and then dropping down to an average concentration of 35 ppb in the last round of sampling in the summer of 2005. During those same sampling events, TCE concentrations were 4 ppb, 58 ppb and then an average of 9 ppb in the last round of sampling. It is believed that this spike and then steady decline in concentrations is attributable to an up gradient source. Similar slugs of contamination have been seen moving through other locations used for monitoring the Upper Glacial aquifer on Long Island; these observations are not surprising given the fact that the groundwater generally moves greater than 1 foot a day in this aquifer.

During the PRM sampling rounds, downgradient wells showed limited TVOIC contamination. All three wells showed no rebound in SIC. TVOIC contamination in MW-9722 fluctuated during this two year sampling period. The PRM phase monitoring confirmed that all site-related contamination in soils and groundwater had been remediated to cleanup levels specified in the ROD expect for those VOCs which were coming on site from off-site sources.

Conclusion. EPA believes that Site related contamination was remediated to ground water restoration standards. The objectives of the 1992 ROD, as modified by the 1995 ROD Amendment, were to address the source of contamination at the Site, the contamination in the surface soils, and ground water contamination attributable to the Pasley Site. By treating the VOC-contaminated soils and ground water by means of SVE/AS, the Pasley Site contaminants were adequately addressed by the remedial actions to cleanup levels specified in the ROD. Although ground water sampling data indicate regional contamination as evidenced by persistent PCE and TCE contamination in wells upgradient and sidegradient of the SVE/AS system before, during and after operation, the objectives of the ROD and the ROD Amendment were met.

Operation and Maintenance

The O&M Manual was approved by EPA in November 1997. The O&M manual documented the information and procedures necessary to allow for effective and efficient operation of the remedial system constructed at the Site. In accordance with the CD and the O&M Manual, the O&M period was to be performed for a minimum of five years to be followed by a PRM period. O&M activities were initiated in November 1997. During the operation of the AS/SVE system, the vapor from each of sixteen on-property and five off-property extraction wells were monitored on a monthly basis. Air discharge, prior to carbon treatment, from the SVE system was monitored on a monthly basis in order to demonstrate the effectiveness of the SVE system to remove VOCs from soil. Ground water monitoring wells were sampled quarterly from November 1997 through October 2000 and semi-annually from November 2000 through March 2003.

The Notice of Completion and Final O&M Report were submitted by Commander in 2003. The report indicated that SICs have met the cleanup standards in ground water and all COCs have met the cleanup standards in soil as specified in the ROD and ROD Amendment. Accordingly, EPA determined that the operation and maintenance was complete, and the Site could progress to the PRM phase. The PRM phase monitoring confirmed that all site-related contamination in soils and ground water had been remediated to cleanup levels specified in the ROD expect for those VOCs which were coming on site from off-site sources. Confirmatory sampling has indicated that all site related contaminants have been remediated to cleanup levels that allow for unlimited use and unrestricted exposure, therefore, no CERCLA O&M activities are necessary.

Five-Year Review

The first five-year review for the Site was completed on August 5, 2004, pursuant to OSWER Directive 9355.7-03B-P. That review, conducted after the RA had been completed and O&M, and monitoring activities had commenced, determined that the RA as designed and constructed pursuant to the ROD Amendment, was performing satisfactorily and that the remedy implemented was protective of human health and the environment. A second five-year review for the Site was completed on July 23, 2009. That review, conducted after the RA and all O&M and Post Remediation Monitoring period activities were completed, determined that the remedy implemented for the Site is protective of human health and the environment in the short-term.

The second five year review made a determination that the remedy for the Site was protective in the short-term because questions arose during the performance of the five year review concerning the adequacy of the data set that was being used in the evaluation of the soil vapor intrusion pathway. Since there was no building on the Site during the implementation of remedial activities, the vapor intrusion pathway had not been evaluated. In response to this concern, EPA's contractor collected 10 soil gas samples from beneath the asphalt parking lot on January 9 and 12, 2006. EPA Region 2 soil vapor intrusion pathway typically recommends collecting sub-slab or indoor air samples. However, that was not possible since the only structure at the Site, an office trailer, does not have a basement or slab. Therefore, sub-slab sampling could not be performed and only soil gas sampling was conducted. A preliminary evaluation of the soil gas data collected at the Site in 2006 identified three of the ten samples at concentrations of potential concern.

To address this potential vapor intrusion pathway, the second five-year review suggested that the Agency issue an explanation of significant differences (ESD) to document a final decision to include institutional controls in the form of a “red-flag” in the computer system of the Town of Hempstead Building Department as part of the overall remedy for the Site. The “red flag” is intended to provide notice of a potential vapor intrusion problem to anyone seeking a construction permit and provide notice to EPA that a permit is being sought to erect a building on the Site. Implementation of this action by the Town of Hempstead Building Department would ensure that before a building permit is granted, the owner would either have to agree to install a soil vapor mitigation system or demonstrate through sampling that a soil vapor mitigation system is not needed. Since the issuance of the second five-year review, EPA has determined that the vapors detected at the Site are from an off-site source and, therefore, an ESD was deemed not to be necessary and CERCLA action is not appropriate. However, the five-year review concluded the institutional control is necessary for the property and currently remains in place. EPA is satisfied that the town notification procedure will adequately address any future vapor intrusion issues at the former site under state authority. Therefore, the Site is protective of human health and the environment.

Since it has been determined that the source of vapors is not related to the CERCLA release, it has been determined that five-year reviews are no longer necessary. The 2009 five-year review was the final review for the Site.

Community Involvement

Public participation activities for this Site have been satisfied as required in CERCLA Section 113(k), 42 U.S.C. 9613(k), and Section 117, 42 U.S.C. 9617. The RODs were subject to a public review process. All other documents and information which EPA relied on or considered in recommending this deletion are available for the public to review at the information repositories.

Determination That the Site Meets the Criteria for Deletion in the NCP

All of the completion requirements for this Site have been met, as described in the August 4, 2011 Final Close-Out Report. The State of New York, in an August 4, 2011 letter concurred with the proposed deletion of this Site from the NPL.

The NCP specifies that EPA may delete a site from the NPL if “all appropriate Fund-financed response under CERCLA has been implemented, and no further response action by responsible parties is appropriate.” 40 CFR 300.425(e)(1)(ii). EPA, with the concurrence of the State of New York, through NYSDEC, believes that this criterion for deletion has been met. Consequently, EPA is deleting this Site from the NPL. Documents supporting this action are available in the Site files.

V. Deletion Action

The EPA, with concurrence of the State of New York through the Department of Environmental Conservation, has determined that all appropriate response actions under CERCLA have been completed. Therefore, EPA is deleting the Site from the NPL.

Because EPA considers this action to be noncontroversial and routine, EPA is taking it without prior publication. This action will be effective September 26, 2011 unless EPA receives adverse comments by September 12, 2011. If adverse comments are received within the 30-day public comment period, EPA will publish a timely withdrawal of this direct final notice of deletion before the effective date of the deletion, and it will not take effect. EPA will prepare a response to comments and continue with the deletion process on the basis of the notice of intent to delete and the comments already received. There will be no additional opportunity to comment.

List of Subjects in 40 CFR Part 300

• Environmental protection
• Air pollution control
• Chemicals
• Hazardous waste
• Hazardous substances
• Intergovernmental relations
• Penalties
• Reporting and recordkeeping requirements
• Superfund
• Water pollution control
• Water supply

Dated: August 5, 2011.

Judith A. Enck,

Regional Administrator, EPA, Region 2.

For the reasons set out in this document, 40 CFR part 300 is amended as follows:

PART 300—[AMENDED]

1. The authority citation for part 300 continues to read as follows:

Authority: 33 U.S.C. 1321(c)(2); 42 U.S.C. 9601-9657; E.O. 12777, 56 FR 54757, 3 CFR, 1991 Comp., p. 351; E.O. 12580, 52 FR 2923; 3 CFR, 1987 Comp., p. 193.

APPENDIX B—[AMENDED]

2. Table 1 of Appendix B to part 300 is amended by removing the entry for “Pasley Solvents & Chemicals, Inc.” “Hempstead, New York”.