Superfund program: National oil and hazardous substances contingency plan National priorities list update,
[Federal Register: July 9, 1998 (Volume 63, Number 131)]
[Proposed Rules]
[Page 37085-37088]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr09jy98-19]
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 300
[FRL-6121-9]
National Priorities List Update; Golden Strip Septic Tank Superfund Site
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice of Intent to Delete the Golden Strip Septic Tank Superfund Site from the National Priorities List (NPL).
SUMMARY: The United States Environmental Protection Agency (US EPA), Region 4, announces its intent to delete the Golden Strip Septic Tank 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 National Oil and Hazardous Substances Pollution Contingency Plan (NCP), which EPA promulgated pursuant to Section 105 of the Comprehensive Environment Response, Compensation, and Liability Act (CERCLA) of 1980, as amended. EPA and the State of South Carolina Department of Health and Environmental Control (SCDHEC) have determined that all remedial action objectives have been met and the Site poses no significant threat to public health or the environment. Therefore, further remedial measures are not appropriate.
DATES: Comments concerning this Site may be submitted on or before August 10, 1998.
ADDRESSES: Comments may be mailed to: Craig Zeller, P.E., Waste Management Division--North Site Management Branch, U. S. Environmental Protection Agency, Region 4, 61 Forsyth St., SW, Atlanta, GA, 30303. You may also submit comments electronically, at the following Email Address, Zeller.Craig@EPAMail.EPA.gov.
Comprehensive information on this Site is available through the public docket, which is available for viewing at the Golden Strip Septic Tank Site information repositories at the following locations:
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Hendricks Branch Library, 626 N.E. Main Street, Simpsonville, SC 29681, (864) 963-9031. U.S. EPA, Region 4, 61 Forsyth St., SW, Atlanta, GA, 30303, Mrs. Debbie Jourdan, 404-562-8862.
FOR FURTHER INFORMATION CONTACT: Craig Zeller, P.E. (404) 562-8827, or Cynthia Peurifoy (404) 562-8798, or toll free at 1-800-435-9233, at U.S. EPA, Region 4, 61 Forsyth St., SW, Atlanta, GA 30303.
SUPPLEMENTARY INFORMATION:
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Introduction
The Environmental Protection Agency (EPA), Region 4 announces its intent to delete the Golden Strip Septic Tank Site at Simpsonville, South Carolina, from the National Priorities List (NPL), Appendix B of the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) 40 CFR part 300, and requests comments on this deletion proposal. EPA identifies sites that appear to present a significant risk to public health, welfare, or the environment and maintains the NPL as the list of these sites. As described in Sec. 300.425(e)(3) of the NCP, sites deleted from the NPL remain eligible for remedial actions in the unlikely event that conditions at the site warrant such actions.
The EPA will accept comments on the proposal to delete this Site for thirty days after publication of this notice in the Federal Register.
Section II of this notice explains the criteria for deleting sites from the NPL. Section III discusses the procedures that EPA is using for this action. Section IV discusses the Golden Strip Septic Tank Site and explains how the Site meets the deletion criteria.
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NPL Deletion Criteria
Section 300.425(e) of the NCP provides that sites may be deleted from, or recategorized on the NPL where no further response is appropriate. In making a determination to delete a site from the NPL, EPA shall consider, in consultation with the State, whether any of the following criteria have been met:
(i) Responsible parties or other parties have implemented all appropriate response actions required;
(ii) All appropriate response actions under CERCLA have 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, taking of remedial measures is not appropriate.
Even if a site is deleted from the NPL, where hazardous substances, pollutants, or contaminants remain at the site above levels that allow for unlimited use and unrestricted exposure, EPA's policy is that a subsequent review of the site will be conducted at least every five years after the initiation of the remedial action at the site to ensure that the site remains protective of public health and the environment.
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Deletion Procedures
The following procedures were used for the intended deletion of this Site: (1) EPA Region 4 has recommended deletion and has prepared the relevant documents; (2) The South Carolina Department of Health and Environmental Control (SCDHEC) has concurred with the proposed deletion decision; (3) Concurrent with this Notice of Intent to Delete, a notice has been published in the local newspaper and has been distributed to appropriate federal, state, and local officials and other interested parties announcing the commencement of a 30-day public comment period on the Notice of Intent to Delete; and (4) All relevant documents have been made available for public review in the local information repository and in the Regional Office.
Deletion of a site from the NPL does not itself create, alter, or revoke any individual's rights or obligations. The NPL is designed primarily for information purposes and to assist EPA management. As mentioned in Section II of this Notice, Section 300.425(e)(3) of the NCP states that deletion of a site from the NPL does not preclude eligibility for future response actions.
For deletion of this Site, EPA will accept and evaluate public comments on this Notice of Intent to Delete before making the final decision to delete. If necessary, the Agency will prepare a Responsiveness Summary to address any significant public comments received during the comment period.
The deletion occurs when the Regional Administrator places the final notice on the Federal Register. Generally, the NPL will reflect deletions in the final update following the Notice. Public notices and copies of the Responsiveness Summary will be made available to local residents by Region 4.
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Basis for Intended Deletion
The following Site summary provides the Agency's rationale for the proposal to delete this Site from the NPL.
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Background
The GSST Site is located on a 55-acre parcel near Simpsonville, South Carolina. The Site is situated in a semi-rural area on a portion of a farm owned by Mrs. Lucille Rice, and is surrounded by the Holly Tree residential subdivision on the east, west and north sides. Primary access to the site is off Adams Mill Road which borders the site to the south. The Carrington Green subdivision is located across Adams Mill Road along the Site's southernmost boundary.
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History
From 1960 through 1975, Mr. Buck Rice (now deceased) operated a septic tank hauling and disposal service from the GSST Site. During this period of active operation, industrial and septic wastes were discharged into five unlined wastewater lagoons located on Site. The total capacity of these five lagoons has been calculated at nearly 2.8 million gallons. Waste hauling and disposal activities at the GSST Site were reportedly discontinued in 1975. By 1978, three of the five lagoons (2, 3 and 5) were backfilled by pushing in the side walls of each unit and covering the sludge.
Preliminary investigations of the Site conducted by SCDHEC and EPA confirmed the presence of inorganic constituents such as cadmium, chromium, copper, lead and cyanide in the lagoon water and sludge. In June 1987, EPA placed the GSST Site on the National Priorities List (NPL).
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Characterization of Risk
A group of responsible parties, known as the Golden Strip Task Group (GSTG), conducted the RI/FS under an Administrative Order by Consent (AOC) with EPA. RMT, Inc., on behalf of the Task Group, conducted the RI field work from September 1989 to March 1991, under EPA and SCDHEC oversight. Lagoon sludges and soils in close proximity to the lagoons were found to be impacted with inorganic constituents. Specifically, maximum concentrations detected in soil and sludge were 12,000 mg/kg cadmium, 97,200 mg/kg chromium, 69,900 mg/kg copper, 4,520 mg/kg cyanide, 5,290 mg/kg lead and 77,600 mg/kg zinc. Toxicity Characteristic Leaching Procedure (TCLP) analyses of lagoon sludge and affected soil demonstrated hazardous characteristics for cadmium. An estimated 1.9 million gallons of water was impounded in Lagoons 1 and 4 and this surface water was found to contain elevated levels of similar inorganic constituents. Three rounds of groundwater sampling indicated that groundwater quality had been affected to a limited extent in the immediate vicinity of the lagoons, but a discernible plume of groundwater contamination was not identified.
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The Baseline Risk Assessment (BRA) concluded that the principal threat to human health posed by this site was exposure to impacted soils and sludges. A residential future-use scenario was utilized in the BRA to develop remedial action target concentrations (RATCs) for impacted soils/sludges. Site specific RATCs were calculated for each Constituent of Concern (COC) identified in the BRA. Data generated during the RI estimated that 28,000 cubic yards of soil/sludge exceeded the applicable RATCs. A Feasibility Study (FS) was performed to evaluate feasible remedial alternatives to address all soil/sludge above applicable RATCs, surface water impounded in Lagoons 1 and 4, and site groundwater.
On September 12, 1991, the Regional Administrator signed a Record of Decision (ROD), which selected a remedy for the GSST Site that was protective of human health and the environment. The major components of the selected remedy included:
‹bullet› Excavation of all soil/sludge above applicable RATCs and treatment by solidification/stabilization to remove hazardous characteristics. Backfilling of treated material into on-site excavations within defined Area of Contamination (AOC);
‹bullet› Establishment of Alternative Concentration Limits (ACLs) for on-site groundwater combined with a long-term monitoring program to monitor the effects of source control on the groundwater;
‹bullet› Discharge of surface waters impounded in Lagoons 1 and 4 to Publicly Owned Treatment Works (POTW); and
‹bullet› Establishment of Conservation Easement to control future use of property.
Active groundwater remediation in the vicinity of the lagoons was not determined reasonable or technically practicable using the decision criteria for ACLs specified in Section 121 of CERCLA. Generally, these include: (1) there is no discernible plume; (2) there are known or projected points of entry of site groundwater into surface water; (3) there is no statistically significant increase in waste constituents in the groundwater or in the surface water at the point of entry; (4) the selected remedy includes source control measures that are expected to have a positive influence on groundwater; and (5) the selected remedy includes enforceable measures that will preclude human exposure to groundwater.
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Implementation of the Selected Remedy
In April 1992, the GSTG entered into a Consent Decree with EPA for implementation of the selected remedy. RMT, Inc. was selected by the task group to perform the necessary Remedial Design and Remedial Action activities required for successful remedy implementation and completion. Extensive treatability studies were conducted to identify cost-effective solidification/stabilization additives that could meet the established leaching and compressive strength performance criteria. It was determined that 30 percent Type I/II Portland cement (based on the dry weight of the soil/sludge matrix) could effectively stabilize and solidify the Site COCs.
The conservation easement, which placed certain restrictions on future site development and usage of the groundwater underlying the site, was filedin Greenville County R.M.C. on January 12, 1994 by Mr. Robert E. Dryden, on behalf of the task group. EPA and SCDHEC granted final approval of the Remedial Design documents and Performance Standards Verification Plan in February 1994. The Remedial Action Work Plan was accepted as Final by EPA and SCDHEC in July 1994. Heritage Environmental Services was selected as the Remedial Action contractor in June 1994 and began initial mobilization to the site on July 6, 1994.
The remedy was initiated in August 1994 by pre-treatment and discharge of the water from Lagoons 1 and 4 to the local sewer. The sludge in each lagoon was then stabilized with affected soil and cement kiln dust. The stabilized sludge and affected soil were then excavated and temporarily staged. Several pilot scale field demonstrations were conducted on the soil/sludge treatment system to evaluate scale-up effectiveness and to implement refinements, where necessary. Heritage Environmental Services demobilized in September 1994, while a supplemental sampling and analysis program was conducted to develop detailed excavation plans.
Screening sampling and analysis, confirmational sampling and analysis, and geostatistical modeling were employed to develop detailed excavation plans for the affected soils and to confirm that the affected soil and sludge had been removed. Heritage remobilized to the site in April 1995 and made several modifications to the pug-mill treatment system. In May 1995, full scale excavation began in Lagoon 1 and proceeded to Lagoon 5. These areas were excavated first so that the final landfill footprint could be excavated, prepared, and confirmed clean prior to the placement of treated soil/sludge. In August 1995, EPA and SCDHEC confirmed achievement of all excavation performance standards in this area and granted approval to proceed with placement of treated material.
Following a final treatment system demonstration, full-scale treatment of affected soils and sludges and further excavation activities proceeded concurrently. Once affected soils were removed, they were fed into a pug mill where they were blended with 30 percent Type I/II Portland cement and water to produce a soil-cement material. This soil-cement material was then taken to the on-site landfill, spread in 1-foot lifts, and compacted. The compacted soil-cement quickly hardened with a compressive strength of greater than 250 psi. This finished landfill was capped with more than 30 inches of soil and a vegetative cover was re-established. An approximated total of 57,000 cubic yards of soil-cement was placed into the on-site landfill cell.
On April 25, 1996, a Pre-Final Inspection was held on-site to verify that all punch list items had been completed. A detailed site walk revealed that all substantive items had been completed with the exception of establishing a vegetative cover and submittal of as-built drawings. The Remedial Action Report was submitted by RMT in June 1996 and approved by the EPA's North Site Management Branch Chief on July 12, 1996. The Final Close Out Report, which documented that the remedial action was successfully completed, was completed by EPA in September 1996.
The GSST Site meets all the site completion and close out procedures for NPL Sites as specified in OSWER Directive 9320.2-09, Close Out Procedures for National Priorities List Sites (EPA/540/R-95/ 062, August 1995). Specifically, excavation verification sampling confirms that all soil above RATCs has been removed, treatment verification sampling confirms that the solidified soil-cement matrix meets leachate and compressive strength performance standards, and that all cleanup actions specified in the ROD have been implemented. Confirmatory stream sampling, groundwater sampling, and a clean cap with vegetative cover provide further assurance that the site no longer poses any risks to human health and/or the environment. The only remaining activity to be performed is O&M which will be conducted by an assigned
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representative of the Golden Strip Task Group.
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Operation and Maintenance
Post-closure activities at the GSST Site will be conducted by the GSTG's assigned representative following the guidelines contained in the EPA/SCDHEC approved Operation and Maintenance (O&M) Plan. Those O&M activities address a 30-year post-closure care monitoring period as specified by the ROD. These post-closure care activities include the following:
‹bullet› Periodic inspections to verify the integrity of the cap, cover and security;
‹bullet› Ongoing landscape maintenance to keep the integrity of the landfill cap intact;
‹bullet› Periodic stream and groundwater monitoring to verify the performance of the remedy; and
‹bullet› Submission of O&M evaluation reports to EPA/SCDHEC containing observations and any corrective actions taken to address issues of concern.
The surficial aquifer underlying the GSST Site has been monitored via sampling and analysis of 22 monitoring wells since 1989. Water quality and sediments of an unnamed stream passing through the site have also been monitored. Since only intermittent exceedances of drinking water standards were observed during the RI/FS, EPA and SCDHEC established ACLs for the site groundwater. During the Site Remedial Action, these ACLs have not been required, as groundwater quality has consistently remained below federally established drinking water levels (Maximum Contaminant Levels). Stream monitoring results continue to verify that the water quality or sediments have not been affected by past waste disposal activities.
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Five-Year Review
Semi-annual groundwater and stream monitoring will continue up to the 5-year review which shall be conducted by July 1999. EPA and SCDHEC will evaluate the scope of future monitoring requirements at the completion of the five-year review.
One of the three criteria for deletion specifies that EPA may delete a site from the NPL if the responsible parties or other parties have implemented all appropriate response actions required. EPA, with the concurrence of SCDHEC, contends this criterion has been met. Subsequently, EPA is proposing deletion of this Site from the NPL. Documents supporting this action are available from the public docket.
Dated: June 22, 1998. A. Stanley Meiburg, Deputy Regional Administrator, U.S. EPA Region 4.
[FR Doc. 98-18083Filed7-8-98; 8:45 am]
BILLING CODE 6560-50-P
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