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Proposed Rule

National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List: Deletion of the New Hanover County Airport Burn Pit Superfund Site

Document Details

Information about this document as published in the Federal Register.

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This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.


Proposed rule; notice of intent.


The Environmental Protection Agency (EPA) Region 4 is issuing a Notice of Intent to Delete the New Hanover County Airport Burn Pit Superfund Site (Site) located in Wilmington, North Carolina, from the National Priorities List (NPL) and requests public comments on this proposed action. 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). EPA, with the concurrence of the State of North Carolina, through the North Carolina Department of Environment and Natural Resources (DENR), has determined that all appropriate response actions under CERCLA have been completed. However, this deletion does not preclude future actions under Superfund.


Comments must be received by July 23, 2012.


Submit your comments, identified by Docket ID no. EPA-HQ-SFUND-1989-0008, by one of the following methods:

  • Online: Follow the instructions for submitting comments.
  • Email:
  • Fax: (404) 562-8788, Attention: Beverly Hudson-Stepter
  • Mail: Beverly Hudson-Stepter, Remedial Project Manager, Superfund Remedial Section B, Superfund Remedial and Site Evaluation Branch, Superfund Division, U.S. Environmental Protection Agency, Region 4, 61 Forsyth Street SW., Atlanta, Georgia 30303-8960.
  • Hand delivery: U.S. Environmental Protection Agency, Region 4, 61 Forsyth Street, SW., Atlanta, Georgia 30303-8960. Such deliveries are only accepted during the Docket's normal hours of operation, and special arrangements should be made for deliveries of boxed information. The Regional EPA Office is open for business Monday through Friday, 8:30 a.m. to 4:30 p.m., excluding holidays.

Instructions: Direct your comments to Docket ID no. EPA-HQ-SFUND-1989-0008. EPA's policy is that all comments received will be included in the public docket without change and may be made available online at, 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 or email. The 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 email comment directly to EPA without going through, your email 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 submitted. 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 index. Although listed in the index, some information is not publicly available, e.g., CBI or other information whose disclosure is restricted by statute. 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 or in hard copy at:

Regional Site Information Repository: U.S EPA Record Center, Attn: Ms. Debbie Jourdan, Atlanta Federal Center, 61 Forsyth Street, SW., Atlanta, Georgia 30303-8960, Phone: (404) 562-8862, Hours 8 a.m.-4 p.m., Monday through Friday by appointment only or

Local Site Information Repository: New Hanover County Public Library, 210 Chestnut Street, Wilmington, North Carolina, Phone: (910) 798-7309 Hours 9 a.m.-8 p.m., Monday and Tuesday, 9 a.m.-6 p.m., Wednesday and Thursday, 9 a.m.- 5 p.m., Friday and Saturday, closed on Sunday.


Beverly Hudson-Stepter, Remedial Project Manager, U.S. Environmental Protection Agency, Region 4, Superfund Remedial Section B, Superfund Remedial and Site Evaluation Branch, Superfund Division, U. S. Environmental Protection Agency, 61 Forsyth Street, Atlanta, Georgia 30311, (404) 562-8816, Electronic mail at:


Table of Contents

I. Introduction

II. NPL Deletion Criteria

III. Deletion Procedures

IV. Basis for Intended Site Deletion

I. Introduction

EPA Region 4 announces its intent to delete the New Hanover County Airport Burn Pit Superfund Site from the National Priorities List (NPL) and requests public comment on this proposed action. The NPL constitutes Appendix B of 40 CFR part 300, which is the 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 40 CFR 300.425(e)(3) of the NCP, sites deleted from the NPL remains eligible for Fund-financed remedial actions if future conditions warrant such actions.

EPA will accept comments on the proposal to delete this site for thirty (30) days after publication of this document in the Federal Register.

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 New Hanover County Airport Burn Pit Superfund Site and demonstrates how it meets the deletion criteria.

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:

1. responsible parties or other persons have implemented all appropriate response actions required;

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

3. 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.

Pursuant to CERCLA section 121(c) and the NCP, EPA conducts five-year reviews to ensure the continued protectiveness of remedial actions where hazardous substances, pollutants, or contaminants remain at a site above levels that allow for unlimited use and unrestricted exposure. EPA conducts such five-year reviews even if a site is deleted from the NPL. EPA may initiate further action to ensure continued protectiveness at a deleted site if new information becomes available that indicates it is appropriate. Whenever there is a significant release from a site deleted from the NPL, the deleted site may be restored to the NPL without application of the hazard ranking system.

III. Deletion Procedures

The following procedures apply to deletion of the Site:

1. EPA consulted with the State of North Carolina prior to developing this Notice of Intent to Delete.

2. The State of North Carolina, through DNER, has concurred on the deletion of the Site from the NPL.

3. Concurrently with the publication of this Notice of Intent to Delete in the Federal Register, a notice is being published in a major local newspaper, Wilmington Star News. 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.

If adverse comments on this deletion notice are received within the thirty (30) day public comment period, EPA will evaluate and respond appropriately to the comments before making a final decision to delete. If necessary, EPA will prepare a Responsiveness Summary to address any significant public comments received. After the public comment period, if EPA determines it is still appropriate to delete the Site, the Regional Administrator will publish a final Notice of Deletion in the Federal Register. Public notices, public submissions and copies of the Responsiveness Summary, if prepared, will be made available to interested parties and in the site information repositories listed above.

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. In addition, 40 CFR Section 300.425(e)(3) 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

New Hanover County Airport Burn Pit Site Superfund Site, (EPA ID: NCD981021157) is located in Wilmington, Brunswick County, North Carolina. The Site consists of a four-acre plot and is located on Gardner Road approximately 500 feet west of the Wilmington International Airport in New Hanover County. The airport is approximately one mile north of Wilmington, North Carolina, at latitude 34°16′29″ north and longitude 77°54′55″ west. The New Hanover County Airport Burn Pit was constructed in 1968. From 1968 to 1979, the Cape Fear Technical Institute (now known as the Cape Fear Community College), used the burn pit for fire-training purposes, burning jet fuel and gasoline in the burn pit, and extinguishing the fires with water. The Wilmington Fire Department used the burn pit for fire-training purposes from 1968 to 1976 and the United States Air Force used the burn pit for fire-training purposes during the Vietnam War.

Jet fuel and drainage from petroleum fuel storage tanks in the area were burned, and the fires were extinguished with water, carbon dioxide, and dry chemicals. Some time prior to 1982, materials used in river spill cleanups were dumped into the burn pit.

In 1986, the North Carolina Division of Health Services discovered heavy metals and numerous organics in the soil around the burn pit and in other nearby soil samples. Surface water within three (3) miles downstream of the Site is used for recreational activities, and an estuary wetland is located approximately one (1) mile from the Site. Approximately 6,300 people obtain drinking water from public and private wells within three (3) miles of the Site. A private well is located approximately 1,500 feet to the northwest of the Site.

To date, the USEPA has identified six (6) potentially responsible parties (PRPs) at the Site: the County of New Hanover, North Carolina; the City of Wilmington, North Carolina; the Cape Fear Community College; the United States Air Force; Axel Johnson Inc. and Sprague Energy Corporation.

The Site was proposed for the NPL on June 24, 1988 (53 FR 23978), and finalized on the NPL March 31, 1989 (54 FR 13296).

Removal Action

EPA negotiated with the City of Wilmington, New Hanover County and Cape Fear Community College in March 1989, for performance of the remedial investigation/feasibility study (RI/FS), but the parties were unable to reach an agreement. In May 1990, however, the parties signed an Administrative Order on Consent (AOC) for a removal action to address all of the source material present on site. The removal began in November 1990 and was completed in December 1990. The removal involved removing waste materials, contaminated water, and contaminated surface and subsurface soils. A total of 12,500 gallons of water were removed from the pit and 6,000 gallons of water were removed from on-site tanks. Contaminated surface and subsurface soils were removed from the firefighter training areas. In addition, structures associated with firefighter training activities were dismantled and removed, including the fuel supply tank and its associated underground piping system, the railroad tank car, the automobile bodies, and the aircraft mock-up. A total of 3,220 tons of contaminated soil and debris were removed. Excavated areas were backfilled to grade with 2,680 cubic yards of clean soil.

Remedial Investigation/Feasibility Study (RI/FS)

EPA conducted a fund-lead RI/FS in 1991 and 1992. Sampling performed indicated that no surface or subsurface soil contamination remained above concentrations that would indicate unacceptable risks to humans or the environment. This was a strong indication that the soil removal action in 1990 was successful in removing contaminated soils. Contaminants detected in the groundwater also included VOCs, SVOCs, and metals. Contaminants were found in both the shallow and deep zones of the upper water bearing formation. No monitoring wells (MWs) were completed in the underlying aquifer. The health risk posed by this NPL site is primarily from the future use of the groundwater as a potable source. This is due to the presence of contaminants at concentrations above EPA's MCLs for drinking water and the State of North Carolina groundwater quality standards.

The Feasibility Study (FS) conducted by CDM and finalized on May 18, 1992 addressed alternatives for groundwater remediation.

Selected Remedy

A ROD was signed on 9/29/1992 to address contaminated groundwater at the site. The remedial action objectives of the ROD were to restore groundwater to beneficial use. The remedy components include:

  • No further action for Site soils;
  • A one-year period for the collection of additional data on the quality of the groundwater;
  • Design and implementation of the groundwater remediation to be initiated after the year of groundwater monitoring. The selected groundwater remediation alternative consists of a groundwater extraction system, an air stripping process to remove volatile organics, and a pipeline discharging the treated groundwater to the Northside POTW system; and
  • A review of the existing groundwater monitoring system to insure proper monitoring of groundwater quality and the effectiveness of the groundwater extraction system. Additional monitoring wells will be added to mitigate any deficiencies. The contaminants of concern (COCs) included benzene, chloroform, 1,2-dichloroethane, and the metals chromium and lead.

The USEPA signed an UAO for Remedial Design/Remedial Action (RD/RA) for the Site on February 28, 1994. A Preliminary Remedial Design report representing 30% design was submitted to the USEPA on December 15, 1994. The USEPA approved the 30% submittal on February 1995. In accordance with the UAO, the PRPs submitted the Intermediate Design Report to the USEPA on June 1, 1995. The Intermediate Design Report did not provide a design for the preferred remedy. Instead, the PRPs submitted the intermediate design which proposed changing the remedy to an air sparging based system. This type of system was not an alternative previously considered; however, its cost could be significantly less than the pump and treat cost while effectively achieving the remediation goals.

The 1992 ROD included metals contamination such as chromium and lead, as COCs. Afterwards, low flow (low turbidity) sampling of select monitoring wells was conducted resulting in no detection of metals. Previously identified metals were associated with preservative leaching of trace metals from high concentrations of solids from previous sampling. Since metals were determined to no longer be COCs, the PRPs requested permission to conduct a study to evaluate current groundwater remediation technologies and their potential applicability to the Burn Pit Site.

The remedial technology considered best for treating the Site related VOCs was Air Sparging. In order to verify its effectiveness at the Burn Pit Site, an Air Sparging Treatability Study was conducted in 1998 and the results were documented in the Air Sparging Pilot Test Treatability Study Report dated December 16, 1998. The Air Sparging Treatability Study results showed air sparging to be very effective at treating the VOCs present in the groundwater at the Site. In June 1998, a Feasibility Study Amendment (FSA) was then conducted to document the comparison of alternatives in the original ROD with the proposed air sparging remedy. The results were documented in the “Air Sparging Pilot Test Treatability Study Report” dated December 16, 1998. The study revealed that air sparging was very effective in treating the VOCs present in ground water at the Site. A feasibility study amendment was conducted to document the comparison of the pump-and-treat remedy selected in the ROD with the proposed air sparging remedy.

Amended Remedy

On April 14, 2000, EPA issued an Amended Record of Decision, in which the Agency selected pulsed air sparging as the new remedy for groundwater. Pulsed air sparging consists of air being injected (as a pulse) into the aquifer through a strategically located network of vertical wells. The injected air travels through the groundwater thereby volatilizing and enhancing biological degradation of the contaminants dissolved in the groundwater.

Response Action

The treatment system consisted of 16 pulse zones; each consisted of five wells for a total of 80 sparge wells. Performance verification and compliance monitoring wells were installed in accordance with the Final Remedial Design Report dated April 2002. Various air sparge wells were installed to test installation methods by verifying the integrity of the constructed seal (bentonite), under normal operating pressures. Upon installation, all air sparge wells were developed prior to testing. Initial testing of sparge well seal integrity was performed on seven sparge wells using a trailer-mounted compressor. Two Sullair compressors alternately produced the air pulse in succession throughout the 80 well systems. The rate of air injected continuously increased and was eventually terminated when a steady state condition was reached. Vapors naturally vented into the atmosphere. Each pulse of air was injected at a pressure of 15 psig and continued for 90 minutes. The recharge time between each pulse of forced air was 23.5 hours. A comprehensive monitoring program was implemented to verify that the treatment system reduced the contaminants.

The system was started in June 2003 and was turned off on January 22, 2010.

Cleanup Goals

The groundwater clean-up levels for the remedy are listed below and based on North Carolina 2L Groundwater Quality Standards (GWQS):

Groundwater Clean-Up Standards

Chemicals of concernPerformance goals
Benzene1 μg/L.
Chloroform0.19 μg/L.
1.2 Dichloroethane0.38 μg/L.
Ethylbenzene29 μg/L.

Laboratory analyses of the groundwater samples collected from site groundwater monitoring and performance verification wells in January 2010 revealed no EPA Method 602 parameter concentrations in excess of applicable 2L GWQS except 1.24 μg/L Benzene in the MWD-002 groundwater sample. The subsequent resampling of monitoring well MWD-002 over four (4) consecutive quarterly sampling events from January 2010 to January 2011 did not reveal any compound concentrations in excess of applicable 2L GWQS.

Operation and Maintenance

No operation and maintenance activities are required for this site.

Five-Year Reviews

The 2008 Five-Year Review found that the selected remedy at the site was protective of human health and the environment in the short-term, because all exposure pathways that could result in unacceptable risks were being controlled. The contaminated soils and waste materials have been removed from the site leaving no remaining source material and the contaminated groundwater is currently being treated and is not being used as a source for potable water. However, if the additional air sparging wells are not effective at treating the remaining contamination, then in order for the remedy to be protective in the long-term, ICs may need to be put in place on the property where contamination is above federal and state MCLs. The ICs were not implemented because groundwater monitoring showed that groundwater contamination met the restoration cleanup levels in 2011. Since no hazardous substances are present on-site above levels allowing for unlimited use and unrestricted exposure, five-year reviews at the site were discontinued.

Community Involvement

EPA has conducted a range of community involvement activities at the Site to solicit community input and to ensure that the public remains informed about site-related activities throughout the cleanup process. Outreach activities have included public notices, interviews and public meetings on cleanup activities. In addition to publishing notices about its intent to delete the Site and amend the ROD in the Federal Register and in a local newspaper, EPA conducted a public meeting on November 30, 1999, to provide the public with the opportunity to comment on the proposed ROD Amendment. The ROD Amendment and Responsiveness Summary, addressing comments received during the comment period, have been included in the Administrative Record.

EPA has also prepared the deletion docket, which includes the documents, which EPA relied on for its decision to propose deleting the Site from the NPL. Therefore, the public participation requirements, required in CERCLA Section 113(k), 42 U.S.C. Section 9613(k), and CERCLA Section 117, 42 U.S.C. Section 9617, have been satisfied.

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

The NCP specifies that EPA may delete a site from the NPL if “all appropriate responsible parties or other persons have implemented all appropriate response actions required.” EPA, with concurrence of the State of North Carolina, through the Department of the Environment and Natural Resources, by a letter dated February 16, 2012, believes this criteria for deletion have been satisfied. The contaminated soils have been removed and the Site meets all the Site completion requirements as specified in Office of Solid Waste and Emergency Response (OSWER) Directive 9320.2-09-A-P, Closeout Procedures for National Priorities List Sites. Specifically, confirmatory sampling verifies that the Site has achieved the ROD cleanup standards, and that all cleanup actions specified in the ROD have been implemented. Therefore, EPA is deleting the Site from the NPL.

List of Subjects in 40 CFR Part 300

Dated: May 11, 2012.

Gwendolyn Keyes Fleming,

Regional Administrator, Region 4.

[FR Doc. 2012-15340 Filed 6-21-12; 8:45 am]