01-19752. National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List

AGENCY:

Environmental Protection Agency.

ACTION:

Notice of Intent to Delete the Shenandoah Stables site from the National Priorities List.

SUMMARY:

The Environmental Protection Agency (EPA) Region 7 announces the intent to delete the Shenandoah Stables site (the 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 Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, as amended. EPA and the State of Missouri Department of Natural Resources (MDNR) have determined that the remedial action for the site has been successfully executed.

DATES:

Comments concerning the proposed deletion of this site from the NPL may be submitted on or before September 6, 2001.

ADDRESSES:

Comments may be mailed to Robert Feild, U.S. Environmental Protection Agency, Region 7, 901 N. 5th Street, SUPR, Kansas City, Kansas, 66101.

Informative Repositories: Comprehensive information on this site is available through the Region 7 public docket which is available for viewing by appointment only. Appointments for copies of the background information from the Regional public docket should be directed to the EPA Region 7 Docket office at the following address: Regional Records Center, U.S. Environmental Protection Agency, Region 7, 901 N. 5th Street, Kansas City, Kansas, 66101.

The deletion docket is also available for viewing at the following location: City Hall, 500 Highway MM, Moscow Mills, Missouri 63362.

FOR FURTHER INFORMATION CONTACT:

If additional information is needed, please contact Robert Feild at [phone] or e-mail at Feild,[e-mail]. The EPA Region 7 toll-free phone number is 1-800-223-0425.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Introduction

II. NPL Deletion Criteria

III. Deletion Procedures

IV. Basis of Intended Site Deletion

I. Introduction

The EPA Region 7 announces its intent to delete the Shenandoah Stables site in Lincoln County, Missouri, from the NPL and requests public comment on this proposed action. The NPL constitutes Appendix B of 40 CFR part 300 which is the NCP, which EPA promulgated pursuant to section 105 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, as amended. The 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. EPA and the MDNR have determined that the remedial action for the site has been successfully executed.

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

Section II of this document explains the criteria for deleting sites from the NPL. Section III discusses the procedures EPA is using for this action. Section IV discusses the Shenandoah Stables site and explains how the site meets the deletion criteria.

II. NPL Deletion Criteria

Section 300.425(e)(1) of the NCP provides that releases may be deleted from, or recategorized on, the NPL where no further response is appropriate. In making a determination to delete a release 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 persons have implemented all appropriate response actions required; or

(ii) All appropriate Fund-financed responses 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, remedial measures are 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. If new information becomes available which indicates a need for further action, EPA may initiate additional remedial actions. Whenever there is a significant release from a deleted site from the NPL, the site may be restored to the NPL, without application of the Hazard Ranking System.

III. Deletion Procedures

The following procedures were used for the intended deletion of this site:

(1) All appropriate response under CERCLA has been implemented, and no further action by EPA is appropriate;

(2) The State of Missouri has concurred with the proposed deletion decision;

(3) A notice has been published in the local newspapers 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 EPA's Notice of Intent to Delete; and

(4) All relevant documents have been made available in the local site information repository.

Deletion of the site from the NPL does not itself create, alter, or revoke any individual's rights or obligations. The NPL is designed primarily for informational purposes and to assist EPA management. As mentioned in section II of this notice, Sec. 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. For deletion of this site, EPA's Regional Office will accept and evaluate public comments on EPA's Notice of Intent to Delete before making a final decision to delete. If necessary, the Agency will prepare a Responsiveness Summary to address any significant public comments received.

A deletion occurs when the Regional Administrator places a final notice in 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 the Regional Office.

IV. Basis of Intended Site Deletion

The following site summary provides the EPA's rationale for the proposal to delete this site from the NPL.

Site Background and History

The Shenandoah Stables facility is located in a rural area along highway US-61 near Moscow Mills, Lincoln County, Missouri, approximately 35 miles northwest of St. Louis, Missouri. The property lies on the upper flood plain terrace of Crooked Creek in a primarily agricultural area. There are a number of single family residences, a livestock operation and other small businesses on approximately 5- to 10-acre parcels around the facility. The predominant land use is pasture land which is primarily vegetated with fescue.

During the early 1970's, activities at Shenandoah Stables included the boarding, training and sale of horses, and the staging of horse shows. Children periodically played in the arena building. Historical records indicate that the indoor arena was sprayed with 1,500 gallons of dioxin-contaminated waste oil to control dust on May 26, 1971. Following the spraying of contaminated waste oil, a number of adverse effects were observed in horses, other animals, and in humans. In August of 1971, the facility owner reportedly removed 6 to 8 inches of the contaminated arena soil from the indoor arena. This material was used as fill for a portion of U.S. Highway 61 adjacent to the Shenandoah Stables property, which was under construction at the time. Potentially contaminated materials placed in the road embankment of U.S. Highway 61 comprise a separate site not included in the NPL site boundary ^[1] . Horses continued to die after this initial excavation. In March 1972, an additional 18 inches of materials were reportedly removed by the site owner from the arena area and buried in a slough area about 75 feet southeast of the arena structure.

Investigation into the disposal practices of a southwestern Missouri chemical manufacturing facility led EPA to the Bliss Waste Oil Company and subsequently to a number of sites that had potentially been sprayed with dioxin-contaminated waste oil for dust control, including the Shenandoah Stables site. Initial sampling of the site in May 1982 showed 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin) levels as high as 1,750 parts per billion (ppb). In 1984, an article was published by a toxicologist with the Centers for Disease Control, Center for Environmental Health (CDC), recommending 1 ppb as a level of concern for dioxin in residential soils. In January 1987, EPA proposed clean-up levels to the CDC for the excavation of the eastern Missouri dioxin sites, including Shenandoah Stables. The CDC concurred with EPA's proposed clean-up levels.

The Shenandoah Stables Site was proposed for the NPL on December 30, 1982, and finalized on the NPL September 8, 1983.

Response Actions

A Record of Decision (ROD) for excavation and interim storage of contaminated soils at the Shenandoah Stables site was issued by EPA on July 28, 1988. Implementation of this remedial action was completed in May 1989. A total of 6,418 tons of dioxin-contaminated materials resulting from soil excavation and arena building decontamination were containerized in bulk solids storage sacks and placed inside wood-framed, steel sided storage structures constructed on site pending final management. Ambient air monitoring was performed during all phases of earth-disturbing activities to assure that implementation of the remedial action did not result in a further release of contaminated materials.

On August 24, 1990, the EPA released the Proposed Plan for Final Management of Dioxin-Contaminated Soil, Shenandoah Stables, Moscow Mills, Missouri. This Proposed Plan presented the EPA's preferred remedy involving transportation of dioxin-contaminated materials currently in storage at the Shenandoah Stables site to the Times Beach site for thermal treatment using the temporary thermal treatment unit, consistent with the September 29, 1988, Times Beach Record of Decision. A ROD was signed for the Shenandoah Stables site on September 28, 1990, that selected off-site thermal treatment of dioxin-contaminated materials at Times Beach as a component of the remedy.

On December 31, 1990, a Consent Decree was entered in the Eastern District of Missouri between EPA, the State, and the primary potentially responsible party (PRP) group. The Consent Decree provided for a mixed work settlement that required each party to undertake certain tasks. Generally, EPA was responsible for excavation and transportation of dioxin-contaminated soils from 26 other eastern Missouri dioxin sites, including Shenandoah Stables, to Times Beach for incineration. The settling defendants were responsible for construction of a temporary incinerator at Times Beach and incineration of dioxin-contaminated materials from the 27 sites (including Shenandoah Stables).

Implementation of activities at Times Beach, including mobilization and operation of the temporary incinerator, was performed by the settling defendants in accordance with the December 1990 Consent Decree. The settling defendants awarded a contract for the temporary incinerator in February 1992. Initial testing of the incinerator was performed in December 1995. Full-scale operation of the incinerator commenced on March 17, 1996, and was completed June 16, 1997. A total of 265,354 tons of dioxin-contaminated materials from the 27 eastern Missouri dioxin sites was treated and disposed at Times Beach. A Certification of Completion for the Shenandoah Stables site was issued to the settling defendants by EPA on August 15, 1997, in accordance with provisions of the 1990 Consent Decree.

Dioxin-contaminated materials from the Shenandoah Stables site were transported to Times Beach by an EPA contractor from August 26, 1996, through October 1, 1996. Additional soil sampling was performed at the Shenandoah Stables site concurrent with the final remedial action. As a result of this sampling, an additional 34 tons of contaminated soil were excavated and transported to Times Beach for treatment during the final remedial action. A total of 6,452 tons of dioxin-contaminated materials from the Shenandoah Stables site was transported to Times Beach for incineration. Ambient air monitoring was conducted during excavation and transportation activities.

Following removal of contaminated materials from interim storage, the three storage buildings were decontaminated by pressure washing and sampled. The storage structures were left on site and abandoned as excess government property. Site restoration at Shenandoah Stables was completed following decontamination of the storage structures in October 1996.

Clean-up Standards

The 1988 ROD for this site established criteria for the removal of soils and other materials contaminated with dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin) from this site. In areas outside the arena, excavation continued until a residual concentration of less than 1 ppb was reached in the upper 12 inches of soil, or until a residual level of less than 10 ppb was reached at a depth greater than 12 inches. In the arena and slough area, excavation continued until a residual concentration of less than 1 ppb was reached in the upper 2 feet of soil, or until a concentration of less than 10 ppb was reached at depths greater than 2 feet. The criteria also provided for a maximum depth of excavation of four feet, or upon encountering bedrock, although these criteria were never applied, since residual dioxin concentrations meeting the previous criteria were achieved prior to reaching this depth or bedrock. During this remedial action, decontamination of the arena building was performed to meet criteria of less than 0.4 pg/cm2 recommended by the Missouri Department of Health (MDOH) and the Agency for Toxic Substances and Disease Registry (ATSDR).

Operation and Maintenance

The remedial response at the site was successful in removing dioxin-contaminated materials exceeding health-based levels for unrestricted use within the boundaries of the NPL site. No operation and maintenance activities are necessary to maintain the continued effectiveness of the remedy.

Five-Year Review

Hazardous substances do not remain at the site above health-based levels following completion of the remedial action. Pursuant to CERCLA Section 121(c) and as provided in the Office of Solid Waste and Emergency Response (OSWER) Directive 9355.7-02, Structure and Components of Five-Year Reviews, May 23, 1991, and OSWER Directive 9355.702A, Supplemental Five-Year Review Guidance, July 26, 1994, EPA is not required to conduct a statutory five-year review for this site. No five-year reviews will be conducted.

Community Involvement

An opportunity for public comment was provided by EPA prior to the excavation and interim storage of dioxin-contaminated soils. A Proposed Plan was released for public comment from June 28, 1988, through July 11, 1988. The Proposed Plan, Operable Unit Feasibility Study, and other documents in the administrative record were made available for public viewing at a local document repository.

The public was first invited to comment on the concept of a comprehensive solution for all of the eastern Missouri dioxin sites at a September 5, 1986, public meeting for the Minker/Stout/Romaine Creek feasibility study. At that meeting, it was announced that the State of Missouri had recommended evaluation of Times Beach as a location for siting a temporary thermal treatment unit and that EPA was evaluating this possibility. At that meeting, EPA announced that a feasibility study would be prepared and released for public comment to evaluate Times Beach as a potential location for centralized thermal treatment of designated eastern Missouri dioxin sites.

The Times Beach Feasibility Study was released for public comment from December 29, 1986, through March 27, 1987. A public meeting was held on February 12, 1987, to discuss alternatives evaluated in the study and to present the Agency's proposed remedy.

The Proposed Plan for Times Beach and the Minker/Stout/Romaine Creek sites was released February 19, 1988. A public comment period was held from February 19 through March 18, 1988, and a public meeting was held in Eureka, Missouri, March 10, 1988. On September 29, 1988, a ROD was signed by the Assistant Administrator, OSWER, that provided for a temporary incinerator to be located at Times Beach for the treatment of dioxin-contaminated materials from the Times Beach and the Minker/Stout/Romaine Creek sites. The ROD further provided that the temporary incinerator would be available to treat dioxin-contaminated materials from the other eastern Missouri sites.

A public meeting to discuss the Shenandoah Stables Proposed Plan for final management of dioxin-contaminated materials was conducted on September 19, 1990, at the Moscow Mills Community Center. Public comments were accepted by the Agency through September 24, 1990. A Responsiveness Summary was prepared which addressed comments received concerning the Shenandoah Stables Proposed Plan.

Applicable Deletion Criteria

One of the three criteria for site deletion 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). The EPA, with the concurrence of the State of Missouri through the MDNR, believes that this criterion for deletion has been met. Subsequently, EPA is proposing deletion of this site from the NPL. Documents supporting this action are available from the docket.

State Concurrence

In a letter dated July 30, 2001, the MDNR concurs with the proposed deletion of the Shenandoah Stables Superfund site from the NPL.

Dated: July 30, 2001.

William W. Rice,

Acting Regional Administrator U.S. EPA Region 7.

Footnotes

1.  The Shenandoah Stables site, site/spill number 0740, CERCLIS ID number MOD980685838 identifies the site appearing on the National Priorities List. The Shenandoah Stables Highway 61 Fill Area, site/spill number 0741, CERCLIS ID number MOD980685846 is not included in the NPL listing.