National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 300

[FRL-5862-9]

National Oil and Hazardous Substances Pollution Contingency Plan;

National Priorities List

AGENCY: Environmental Protection Agency.

ACTION: Notice of Intent to Delete Union Pacific Railroad Sludge Pit

Site from the National Priorities List Update: Request for Comments.

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SUMMARY: The Environmental Protection Agency (EPA), Region 10,

announces its intent to delete the Union Pacific Railroad (UPRR) Sludge

Pit Site in Pocatello, Idaho 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 Idaho Division of Environmental Quality (IDEQ)

have determined that the Site poses no significant threat to public

health or the environment and, therefore, further remedial measures

pursuant to CERCLA are not appropriate.

DATES: Comments concerning this Site may be submitted on or before

August 25, 1997.

ADDRESSES: Comments may be mailed to: Deborah J. Yamamoto,

Environmental Protection Agency, 1200 Sixth Avenue, Mail Stop ECL-113,

Seattle, Washington 98101.

Comprehensive information on this Site is available through the

Region 10 public docket which is available for viewing at the UPRR

Sludge Pit Site information repositories at the following locations:

Pocatello Public Library, 113 S. Garfield, Pocatello, Idaho 83204.

United States Environmental Protection Agency, Region 10 Office of

Environmental Cleanup--Records Center, Attn: Bob Phillips, 1200 Sixth

Avenue, Mail Stop ECL-110, Seattle, Washington 98101.

FOR FURTHER INFORMATION CONTACT: Deborah J. Yamamoto, U.S. EPA Region

10, 1200 Sixth Avenue, Mail Stop ECL-113, Seattle, Washington 98101,

(206) 553-7216.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Introduction

II. NPL Deletion Criteria

III. Deletion Procedures

IV. Basis for Intended Site Deletion

I. Introduction

The Environmental Protection Agency (EPA), Region 10 announces its

intent to delete a site 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 to this

deletion. EPA identifies sites on the NPL that appear to present a

significant risk to human health or the environment. As described in

Sec. 300.425(e)(3)of the NCP, sites deleted from the NPL remain

eligible for Fund-financed remedial actions in the unlikely event that

conditions at the site warrant such actions.

EPA plans to delete the Union Pacific Railroad Sludge Pit Site

(``Site'') at 300 South Harrison, Pocatello Idaho, 83201, from the NPL.

EPA will accept comments on the plan to delete this Site for thirty

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 UPRR Sludge Pit Site and

explains how the Site meets deletion criteria.

II. NPL Deletion Criteria

Section 300.425 (e) of the NCP provides that ``releases'' (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 Fund-financed responses under CERCLA have

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.

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

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after the initiation of the remedial action at the site to ensure that

the site remains protective of public health and the environment. In

the case of the UPRR Sludge Pit Site, no hazardous substances were left

on-Site, making ``unlimited use and unrestricted exposure'' possible.

Therefore, the five-year review requirement of Section 121 (c) of SARA

is not applicable. If, however, new information becomes available that

indicates a need for further action, EPA may require remedial actions.

Whenever there is a significant release from a site deleted from the

NPL, the site may be restored to the NPL without the application of the

Hazard Ranking System.

III. Deletion Procedures

The following procedures were used for the intended deletion of

this Site: (1) EPA Region 10 issued a final close out report

documenting the achievement of cleanup goals; (2) The Idaho Division of

Environmental Quality (IDEQ) concurred with the proposed deletion

decision; (3) 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 EPA's Notice of Intent to Delete; and, (4) All

relevant documents have been made available for public review in the

local Site information repository.

Deletion of the Site from the NPL does not itself, create, alter or

revoke any individual rights or obligations. The NPL is designed

primarily for information purposes to assist EPA management. As

mentioned in Section II of this document, 40 CFR 300.425(e)(3) states

that deletion of a site from the NPL does not preclude eligibility for

future Fund-financed response actions.

EPA's Regional Office will accept and evaluate public comments on

EPA's Notice of Intent to Delete before making a final decision. The

Agency will prepare a Responsiveness Summary if any significant public

comments are received.

A deletion occurs when the Regional Administrator places a final

action 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 EPA's Regional Office in Seattle, Washington.

IV. Basis for Intended Site Deletion

The following Site summary provides the Agency's rationale for the

intention to delete this Site from the NPL.

A. Site Background

The UPRR Sludge Pit Site is located at 300 South Harrison in

Pocatello, Bannock County, Idaho. The Site is approximately one acre in

size, and is located north of UPRR's West Pocatello Railroad Yard, a

several hundred acre facility located northwest of the City of

Pocatello. The McCarty's/Pacific Hide and Fur Superfund site is

directly northeast of the sludge pit. The Site is located in an area of

mixed commercial and light industrial property.

B. History

UPRR has operated a railroad yard on the property since the turn of

the century. Operations have included maintenance and repair work,

train assembly, and refueling. Railroad operations have involved the

use of various fuels, cleaning agents, detergents and degreasers,

including solvents.

UPRR operates a waste water treatment plant (oil/water separator

and dissolved air flotation unit). The treatment plant receives water

from all rail yard storm drains and from many building floor drains.

Between 1961 and 1983, approximately 3,000 gallons per week of sludge

generated by treatment of the waste water at the plant were collected

and disposed in an unlined pit.

An EPA site investigation conducted in 1983 found that seepage from

the sludge pit and a former railroad tie treating facility contributed

to ground-water contamination beneath the pit. Ground-water samples

from nearby private wells contained low levels of organic compounds

consistent with the wastes discharged to the pit. As a result of this

investigation, the Site was placed on the NPL in 1984 (49 FR 37083).

The sludge pit was investigated and sampled by UPRR as part of a

remedial investigation (RI) that lasted from 1985 to 1988. A variety of

contaminants, including heavy metals (cadmium, chromium, copper, lead

and zinc), volatile and semi-volatile organic compounds (ethylbenzene,

xylenes, trans-1,2-dichloroethene, tetrachloroethene, polycyclic

aromatic hydrocarbons (PAHs), nitrosamines, dichlorobenzene and a

phthalate) were found in the sludge (and to a lesser extent, the

underlying soil and silt) at the Site during the RI. Contamination in

ground water consisted primarily of PAHs, as nonaqueous phase liquids

(NAPLs), floating on the surface of the water table in the upper

aquifer below the sludge pit. Low levels of heavy metals, semi-volatile

and volatile organic compounds (VOCs) found in the sludge were also

found in the ground water.

The RI found that the sludge posed the greatest risk to human

health through possible direct contact and as a continuing potential

source to ground-water contamination. During 1990, UPRR finalized the

RI, as well as the human health and ecological risk assessment. The

feasibility study (FS) was completed in early 1991.

Based on the results of the RI/FS and risk assessment, EPA signed a

Record of Decision (ROD) for the Site on September 10, 1991. The

selected remedial action in the ROD included the following components:

Excavation and off-site disposal of contaminated soil,

silt, and sludge to the maximum extent practicable; treatment of

excavated material that failed the toxicity characteristic leachate

procedure test; excavated areas backfilled with clean fill and graded;

construction and maintenance of a low permeability cap over the entire

pit boundary, and construction of a permanent fence around the entire

sludge pit.

Treatment of remaining, unexcavated soil and NAPL-

contaminated ground water via soil flushing, an on-Site oil/water

separator and a dissolved air flotation unit (DAF); effluent discharge

to the publicly owned treatment works (POTW) and residual sludge tested

and appropriately disposed off-site.

Provision for design and installation of an alternate

water supply system in the event that the system is deemed necessary.

Implementation of administrative and institutional

controls in the property deed such as air monitoring, ground-water

monitoring, and land and water use restrictions.

Implementation of quarterly ground-water monitoring for

all on-Site wells, at a minimum, for the first three years following

completion of remedial activities.

Implementation of comprehensive on- and off-Site soil and

ground-water sampling, prior to initiation of the remedial action (RA),

to determine background levels and the extent to which on-Site

concentrations exceed background.

In 1992 and 1993, UPRR undertook several remedial design (RD)

support activities, including sampling soil and ground water to

determine background concentrations, and three rounds of

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ground-water sampling of all on-Site monitoring wells to establish

baseline VOC, PAH, and metals concentrations. In addition, UPRR

conducted a soil treatability study to test tap water and commercially

available surfactants as potential soil flushing solutions for use in

the in situ soil flushing system.

Based on the results of the pre-RD activities, EPA determined that

an amendment to the ROD was necessary. The Amended ROD, signed on

September 29, 1994, set forth the final remedial performance standards

and cleanup levels for contaminants at the Site. The Amended ROD also

modified the original remedy by eliminating the requirements to install

an in situ soil flushing system, the DAF treatment component of the

ground-water pretreatment system, and the permanent Site fence.

Based on the treatability study test results and the tests

performed on the contaminated soil beneath the sludge pit, EPA

concluded that in situ soil flushing would not achieve the goal of

improving or providing appreciable protection of the ground water. The

tests also showed that the DAF unit was not needed since contaminant

concentrations in leachate and the upper aquifer were significantly

below the required discharge limits mandated by the POTW. The DAF unit

was not suitable for removal of the free oil whereas the oil/water

separator, which remained a part of the pretreatment system, was

designed for that purpose. UPRR installed a temporary fence during

remedial action for Site security and to protect the public from

physical contact with contaminated material during construction. Since

contaminated material in the sludge pit was excavated and filled with

clean material, future exposure to contaminated soil was eliminated

once construction activities were completed, thereby eliminating the

need for a permanent fence.

C. Characterization of Risk

Prior to cleanup, the preliminary environmental pathways of concern

were potential direct contact with sludge in the pit and potential

ingestion of contaminated ground water. The estimated pre-remediation

site-specific cancer risk for ground water was 1 x 10-3.

Remedial action began in 1994 and included excavation of the sludge

pit, filling the pit with clean material, installation of a geomembrane

cover, no-dig barrier and final grading. All contract work was

completed by the end of November 1994.

UPRR began ground-water monitoring in July 1994 and ground-water

extraction/treatment in late November 1994. In July 1995, UPRR

submitted documentation that performance monitoring results indicated

achievement of the ground-water performance standards. UPRR conducted

its first round of long-term ground-water compliance monitoring on July

21, 1995. On August 8, 1995, EPA approved shut down of the ground-water

extraction/treatment system. UPRR has conducted four rounds of long-

term compliance monitoring since July 1995.

Removal of contaminated sludge and installation of a cover over the

former sludge pit has eliminated direct contact as a potential route of

exposure and removed the source of ground-water contamination.

Analytical data from four rounds of ground-water compliance monitoring

indicate that concentrations of contaminants of concern are below ROD

cleanup levels. Current Site risk from chemicals of concern is 7 x

10-5, which is less than the ROD cleanup level of 1 x

10-4 cumulative cancer risk for combined residential/

industrial land use.

With the implementation and completion of all remedial activities,

the Site no longer poses any threat to human health or the environment,

insuring that no further action is required. With the exception of

decommissioning of the extraction/treatment system and abandoning of

monitoring wells, there are no other operation and maintenance

activities to be performed at the Site. No hazardous substances were

left on-Site above levels that allow for unlimited use and unrestricted

exposure; therefore, the five year review requirement of Section 121

(c) of SARA is not applicable.

D. Public Participation

Community input has been sought by EPA Region 10 throughout the

cleanup process at the Site. Information repositories were established

at the Southeastern Idaho Health District Office and at the Pocatello

Public Library. Fact sheets were distributed in 1988, 1989, and 1990,

and the proposed plan for cleanup was issued in 1991. Additional fact

sheets were distributed in September 1992 and July 1994.

A copy of the Deletion Docket can be reviewed by the public at the

Pocatello Public Library, or the EPA Region 10 Superfund Records

Center. The Deletion Docket includes this document, the ROD, Amended

ROD, Remedial Action Construction Report, and Final Site Close-Out

Report. EPA Region 10 will also announce the availability of the

Deletion Docket for public review in a local newspaper and

informational fact sheet.

One of the three criteria for deletion specifies that EPA may

delete a site from the NPL if ``responsible parties or other persons

have implemented all appropriate response actions required.'' EPA, with

the concurrence of IDEQ, believes that this criterion for deletion has

been met. Ground-water and soil data from the Site confirm that the ROD

cleanup goals have been achieved. There is no significant threat to

human health or the environment and, therefore, no further remedial

action is necessary. Consequently, EPA is proposing deletion of this

Site from the NPL. Documents supporting this action are available in

the docket at the information repositories.

Dated: July 10, 1997.

Chuck Clarke,

Regional Administrator, Region 10.

[FR Doc. 97-19545 Filed 7-24-97; 8:45 am]

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