National Oil and Hazardous Substances Pollution Contingency Plan, National Priorities List Update

AGENCY:

Environmental Protection Agency.

ACTION:

Notice of intent for partial deletion of the Cimarron Mining Superfund Site from the National Priorities List.

SUMMARY:

The Environmental Protection Agency (EPA) Region 6 announces its intent for partial deletion of the Cimarron Mining Superfund Site from the National Priorities List (NPL) and requests public comment on this action. All public comments regarding this proposed action will be considered by EPA. The NPL, promulgated pursuant to section 105 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, as amended, is codified as Appendix B to the National Oil and Hazardous Substances Pollution Contingency Plan (NCP), 40 CFR part 300. The proposed partial deletion of the Cimarron Mining Site is in accordance with 40 CFR 300.425 (e) and the Notice of Policy Change: Partial Deletion of Sites Listed on the NPL. EPA, in consultation with the New Mexico Environment Department (NMED), has determined that all appropriate response actions under CERCLA have been implemented to protect human health, welfare, and the environment at the portions of the site for which deletion is being proposed. This partial deletion includes all portions of the Cimarron Operable Unit (OU1) and the Sierra Blanca Operable Unit (OU2) except for the long-term ground water remedy at OU1.

DATES:

Comments must be submitted by July 21, 2000.

ADDRESSES:

Comments may be mailed to: Ms. Petra Sanchez, Remedial Project Manager (6SF-LT), U.S. Environmental Protection Agency, Region 6 1445 Ross Avenue, Dallas, Texas 75202-2733, (214) 665-6686 or (800) 533-3508.

Information Repositories: Comprehensive information on the site has been compiled in a public deletion docket which may be reviewed and copied during normal business hours at the following information repositories:

U.S. EPA Region 6 Library (12th Floor) 1445 Ross Avenue Dallas, Texas 75202-2733

New Mexico Environment Department, P.O. Box 26110, 11909 St. Francis Dr., Santa Fe, New Mexico 87503

Carrizozo City Hall P.O. Box 247, Carrizozo, New Mexico 88301

FOR FURTHER INFORMATION CONTACT:

Ms. Petra Sanchez, Remedial Project Manager (6SF-LT), U.S. Environmental Protection Agency, Region 6,1445 Ross Avenue Dallas, Texas 75202-2733 (214) 665-6686, 1-800-533-3508.

Mr. David Henry, New Mexico Environment Department, 1190 St. Francis Dr., P.O. Box 26110, Santa Fe, New Mexico 87503, (505) 827-0037.

SUPPLEMENTARY INFORMATION:

Table of Contents:

I. Introduction

II. NPL Deletion Criteria

III. Partial Deletion Procedures

IV. Basis for Intended Partial Site Deletion

I. Introduction

This document was prepared by EPA Region 6 as Notice of Intent for Partial Deletion (Notice or NOIPD) of the Cimarron Mining Superfund Site (EPA Site Spill No. 06B5; CERCLIS No. NMD980749378), from the National Priorities List (NPL). The NPL is the list compiled by EPA pursuant to CERCLA section 105 of uncontrolled hazardous substance release sites in the United States that are priorities for long-term remedial evaluation and response. As described in 40 CFR 300.425(e)(3) of the National Contingency Plan (NCP), sites deleted from the NPL remain eligible for remedial actions in the unlikely event that conditions at the site warrant such action.

The EPA will consider comments concerning this document which are submitted within thirty days of the date of this Notice. The EPA has also published an advertisement of the availability of this Notice in the Albuquerque Journal and Lincoln County News.

Section II of this Notice of Intent for Partial Deletion explains the National Contingency Plan criteria for deleting sites from the National Priorities List. Section III discusses procedures that EPA is using for this action. Section IV discusses the Cimarron Mining Superfund Site and explains that portions of the site meet the NCP deletion criteria.

II. NPL Deletion Criteria

The NCP, at 40 CFR 300.425(e), provides that sites may be deleted from the NPL if 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 has 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 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.

If, at the site of a release, EPA selects a remedial action that results in any hazardous substances, pollutants, or contaminants remaining at the site, CERCLA subsection 121(c), 42 U.S.C. 121(c), requires that EPA review such remedial action no less often than each 5 years to ensure that human health and the environment are being protected by the remedial action. Since hazardous substances will remain at the site, EPA shall conduct such reviews. If new information becomes available which indicates a need for further action, EPA may initiate further remedial actions. Whenever there is a significant release from a site deleted from the NPL, the site may be restored to the NPL without application of the Hazard Ranking System (HRS).

III. Partial Deletion Procedures

EPA followed these procedures regarding the proposed partial deletion:

(1) EPA Region 6 made a determination that no further response action is necessary and that portions of the site may be deleted from the NPL;

(2) EPA has consulted with the appropriate environmental agency, the New Mexico Environment Department (NMED), and NMED concurs with EPA's partial deletion decision;

(3) EPA has published, in a major local newspaper of general circulation at or near the site, an advertisement of availability of this Notice, which includes an announcement of a 30-day public comment period regarding the Notice, and EPA distributed the Notice to appropriate State, local and Federal officials, and to other interested parties; and

(4) EPA placed copies of information supporting the proposed deletion (i.e., the public deletion docket) in the site information repositories (the locations of these repositories are identified above).

Deletion of a site from the NPL does not itself create, alter, or revoke any individual's rights or obligations. As mentioned in Section II of this Notice, 40 CFR 300.425(e)(3) of the NCP states that the deletion of a site from the NPL does not preclude eligibility of the site for future response actions.

EPA Region 6 will accept and evaluate public comments on this Notice before making a final decision to delete. If necessary, EPA will prepare a Responsiveness Summary to address any significant public comments received.

IV. Basis for Intended Partial Site Deletion

A. Site Location and Description

The Cimarron Mining Site has two operable units (OUs). The first operable unit (OU-1) is located approximately 1/4 mile east of Carrizozo, Lincoln County, New Mexico, and approximately 100 miles south-southeast of Albuquerque, New Mexico. The site is about 10.6 acres in size, and is located in the NE1/4 of Section 2, Township 8S, Range 10E, on the north side of Highway 380 (see Appendix A). The site consisted of a conventional agitation mill, which resulted in unpermitted discharge of contaminated liquids and the stockpiling of contaminated liquids, tailings and other waste sediment. Access to the site is restricted by an 8-foot fence. Approximately 1500 people live within a two mile radius of the site.

The Sierra Blanca Operable Unit (OU2) is located approximately one mile south of OU1 and comprises approximately 7.5 acres. The Sierra Blanca OU was designed and operated similarly to the Cimarron mill with the exception that cyanide was apparently not used at Sierra Blanca. The site file information from EPA and NMED discusses a possible spill occurring at Cimarron that most likely prompted milling operations to be relocated to Sierra Blanca in June of 1982. The Sierra Blanca milling location included two buildings, four discharge pits, one cinder block trench, a septic tank system, and numerous process tanks and material piles.

B. History

The Cimarron Mining Corporation site is an inactive milling facility originally owned by Zia Steel Inc., and used to recover iron from ores transported to the site. The iron recovery process took place between the late 1960's and 1979 and involved crushing of the ore material, creating a liquid slurry by mixing with water and collecting the ferric (iron) portion of the mix by using a magnetic separator. Cyanide was not used in this original process. Tailings from the process were transported away from the site and used as fill material in local construction projects. In 1979, the site was sold to Southwest Minerals Corporation. Southwest Minerals began using cyanide soon thereafter to extract precious metals from ore. Details on the operation between 1979 and 1981 are not available other than a 1980 New Mexico Environmental Improvement Division (NMEID) sample analysis report. The report cited the presence of cyanide contamination in OU 1. Southwest Minerals, a subsidiary of Sierra Blanca Mining and Milling Company, operated at the site without the permits required for conducting cyanide processing. In mid-1981, the operation was expanded by adding several large mixing tanks, cyanide solution tanks and associated pumping and conveyance equipment. The NMEID sent a certified notice of violation to the property owner on June 22, 1982, for discharging into a non-permitted discharge pit and, in July 1982, the site ceased operation. No legal action was taken by the State; the company filed for bankruptcy in July 1983, and a court assigned bankruptcy trustee was appointed for the site.

Field inspections of the site by NMEID in February 1980, June 1982, and in May and June 1984, revealed the presence of cyanide and elevated metals in shallow ground water, soil and mill tailings. An Expanded Site Inspection (ESI) was conducted from January to October 1987 by an EPA Field Investigation Team (FIT). The objective of the ESI was to collect additional data for the Hazard Ranking System (HRS) and to facilitate the Remedial Investigation/Feasibility Study (RI/FS) planning.

On-site activities performed during the ESI included surface and subsurface soil sampling, visual inspection of process tanks, sampling of remnant materials in the tanks, quantifying waste volumes, sampling and geologically describing subsurface soil borings during installation of monitoring wells, sampling ground water in the monitoring wells and in nearby water supply wells, testing insitu permeability at the monitor wells, and identifying adjacent land uses.

Based on the findings of site investigations and the preparation of the HRS package, the Cimarron Mining Corporation Site was proposed for addition to the National Priorities List (NPL) on June 24, 1988, and finalized on October 4, 1989.

The OU1 selected remedy for ground water treatment consists of extracting contaminated shallow ground water and discharging to the City of Carrizozo sewage treatment plant, meeting all pretreatment requirements prior to discharge. Ground water treatment in OU1 will continue as long as it demonstrates effective, or, until the site is taken over by the state in 2004. The OU2 selected remedy includes the excavation and treatment of arsenic and lead contaminated soils by mixing the soils with cement and placing them in the on-site discharge pit with a native soil cover and native re-vegetation. Pursuant to section 104(c)(6) of CERCLA, EPA is authorized to share the cost of restoration of the ground water for a period of up to ten years or until the level of protectiveness, as defined in the Record of Decision, is achieved. The ten-year period began when the ground water remedy at the Cimarron Unit became operational and functional and adheres to the statutory provisions in 40 CFR 300.435(f)(3) and 300.435(f)(4). Based on mutual agreement between EPA and NMED, the ground water extraction and treatment system was deemed operational and functional beginning January 30, 1994.

C. Characterization of Risk

Due to remedial actions by EPA and NMED, and the long term remedial action for contaminated ground water, EPA verifies the implemented remedy for the portions of the site proposed to be deleted is protective of human health and the environment.

D. Community Involvement

Public participation activities have been satisfied as required in CERCLA subsection 113(k), 42 U.S.C. 9613(k), and in CERCLA section 117, 42 U.S.C. 9617. Documents in the deletion docket on which EPA relied for recommendation of the site partial deletion from the NPL have been made available to the public in the three information repositories as specified above.

E. Proposed Action

In consultation with NMED, EPA has concluded that all appropriate response actions required at portions of the site proposed to be deleted have been met. Neither the CERCLA-required five-year reviews nor operation and maintenance of the ground water remedy are considered further response action for these purposes. The ground water remedy for OU 1, which is the portion of the site not being proposed for deletion, will continue until the remedial action level for cyanide has been met or an alternate treatment and/or remedial action level is selected by EPA and the State.

In a letter dated January 25, 1999, NMED formally concurred with the partial deletion of the site and stated NMED's satisfaction with all completed remedial tasks as defined in the ROD. Moreover, EPA, in consultation with NMED, has determined that site surface soils at both OU 1 (Cimarron) and OU 2 (Sierra Blanca) now pose no significant threat to public health or the environment and that the Sierra Blanca site is suitable for future redevelopment. Consequently, EPA proposes this partial deletion of the Cimarron Mining Superfund Site.