40784 Federal Register / Vol. 62, No. 146 / Wednesday, July 30, 1997 / Proposed Rules

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Part 300

[FRL–5864–3]

National Oil and Hazardous

Substances Pollution Contingency

Plan; National Priorities List

AGENCY: Environmental Protection

Agency.

ACTION: Notice of intent to delete Silver

Mountain Mine from the National

Priorities List.

SUMMARY: The Environmental Protection

Agency (EPA) Region 10 announces the

intent to delete the Silver Mountain

Mine 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 Washington

Department of Ecology (Ecology) have

determined that the remedial action for

the site has been successfully executed.

DATES: Comments on this site may be

submitted to EPA on or before August

29, 1997.

ADDRESSES: Comments may be mailed

to: Anne D. Dailey, U.S. Environmental

Protection Agency, 1200 Sixth Avenue,

Mailstop ECL–111, Seattle, WA 98101.

Comprehensive information on this

site is available through the Region 10

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 10 docket

office at the following address:

SUPERFUND Records Center, U.S.

Environmental Protection Agency,

Region 10, 1200 Sixth Avenue, Seattle,

WA 98101.

The deletion docket is also available

for viewing at the following location:

County Clerks Office, Okanogan

County Courthouse, 149 N. 3rd,

Okanogan, Washington 98840.

FOR FURTHER INFORMATION CONTACT:

Anne D. Dailey, U.S. Environmental

Protection Agency, 1200 Sixth Avenue,

Mailstop ECL–111, Seattle, WA 98101,

(206) 553–2110 or 1–800–424–4372.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Introduction

II. NPL Deletion Criteria

III. Deletion Procedures

IV. Basis of Intended Site Deletion

I. Introduction

The U.S. Environmental Protection

Agency (EPA) Region 10 announces its

intent to delete the Silver Mountain

Mine site in Okanogan County,

Washington, 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 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 State of Washington

Department of Ecology (Ecology) have

determined that the remedial action for

the site has been successfully executed.

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 Silver

Mountain Mine 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 parties

have implemented all appropriate

actions required;

ii. All appropriate 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

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

restricted 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.

In the case of this site, the selected

remedy is protective of human health

and the environment. Consistent with

the State Superfund Contract, Ecology

has agreed to take over operation and

maintenance of the site and conduct an

annual inspection. EPA has conducted

the first five-year review of the final

remedy, and will also perform future

five-year reviews.

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)

Ecology 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

repositories.

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

Agency management. As mentioned in

section II of this notice, § 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.
Federal Register / Vol. 62, No. 146 / Wednesday, July 30, 1997 / Proposed Rules 40785

IV. Basis of Intended Site Deletion

The following site summary provides

the Agency’s rationale for the proposal

to delete this site from the NPL.

Site Background and History

Silver Mountain Mine is an

abandoned heap-leach mining operation

located approximately six air miles

northwest of Tonasket, in Okanogan

County, Washington. The site consists

of five acres of range land on a 358-acre

tract of privately owned land. The site

was placed on the NPL in 1984 due to

concerns about a cyanide-contaminated

leachate pond, saturated mine tailings,

and the potential for arsenic and

cyanide contamination of the regional

ground water aquifer.

The risk assessment identified arsenic

and cyanide as the primary

contaminants of concern. The Remedial

Investigation (RI) identified and

evaluated three potential sources of

contaminants at the site: the heap leach

pile, the unprocessed rock, and the

mine drainage water. Potential exposure

pathways for contaminants were

identified as: On-site soils, on-site

surface water, on-site ground water in a

shallow aquifer, and off-site ground

water in the region. During the RI, the

highest arsenic levels found were in the

mined material (1080 mg/kg) and in the

water from a stock water tank (95 ug/l).

Both arsenic and cyanide were also

found in the perched shallow aquifer

just at the edge of the heap leach pile.

The Feasibility Study screened

twenty-three various methods of

cleaning up the site. From this list, eight

alternatives were developed and

evaluated against criteria listed in the

NCP. Alternatives ranged from capping

on-site to treatment and off-site

disposal.

Response Actions

The Record of Decision (ROD) for

Silver Mountain Mine was signed on

March 27, 1990, and included a number

of construction elements to implement

the Remedial Action. In October 1994,

EPA completed an Explanation of

Significant Differences (ESD) to

document changes in the Remedial

Action due to unforeseen conditions

encountered at the site during

implementation of the selected remedy.

The remedial action at the site

ultimately included:

—Consolidating and contouring

contaminated mine waste overburden

and tailings,

—Covering and capping the site with a

soil and clay cap,

—Fencing the site to protect the cap and

allow seeded grass cover to develop,

—Closure of the mine entrance and

diversion of the mine drainage so that

it flows away from the site, and

—Deed restrictions on property to

protect the cap.

Construction was completed during

1992 and the deed restrictions were

finally obtained in December 1996.

The five-year review inspection

occurred on May 27, 1997, and

determined that the remedial objectives

have been achieved. The constructed

remedy is performing as designed and is

controlling the risks to human health

and the environment as specified in the

ROD and ESD. The cap was in excellent

shape with no evidence of subsidence,

erosion, or animal burrows. The grass

cover is well established and provides

thorough coverage of the cap; minimal

weeds and woody vegetation were

growing on the cap. The mine entrance

and mine vent were both closed and

covered with rocks.

Cleanup Standards

The remedial action cleanup activities

at the Silver Mountain Mine site are

consistent with the objectives of the

NCP and will provide protection to

human health and the environment. The

cleanup standards for the heap leach

pile and mine dump materials and the

surrounding soils are 200 mg/kg for

arsenic and 95 mg/kg for total cyanide.

According to the data obtained during

the construction work, the cyanide in

the soils is below detection (0.5 mg/kg),

and the concentrations of arsenic that

remain in the areas that were cleaned up

are less than 100 mg/kg. Risks at the site

have been reduced below the Hazard

Index of 1.0 or health based levels; and

for arsenic, a human carcinogen, the

cancer risk factor has been reduced

below one in ten thousand.

The major source of contaminants

identified in the ROD, the rock material

from the mining operations (heap and

mine dump), has been addressed. The

mine drainage was reevaluated in the

Explanation of Significant Differences

and it was determined that the mine

drainage did not pose an ecological

threat. According to the risk assessment

and amended risk assessment, the

inhalation and ingestion of the

contaminated soils were the major

routes of exposure. The arsenic-laden

waste rock from the mine was contained

and capped. The cleanup also reduced

the impacts to the ground water by

diverting the run-on water away from

the capped mine waste and by limiting

potential leachate generation.

Operations and Maintenance

The site is designed to require very

little maintenance. The area is remote

and the semi-arid climatic conditions

suggest that only minimal maintenance

is expected. The mined rock material

under the cover is not expected to settle

which is often the major cause of cap

disturbance. The rainfall is low with an

annual average precipitation of 11

inches/year which is primarily as snow

and spring rain. It is expected that the

Ecology personnel, per the State

Superfund Contract, will be able to

provide the annual maintenance with a

minimal amount of work.

Five-Year Review

The Comprehensive Environmental

Response, Compensation and Liability

Act (CERCLA or Superfund) requires a

five-year review of all sites with

hazardous substances remaining above

the health-based levels for unrestricted

use of the site. Since the cleanup of the

Silver Mountain Mine site utilized

containment of the hazardous materials

as the method to reduce the risk, the

five-year review process will be used to

insure that the cap is still intact and

blocking exposure pathways for human

health and the environment. As

indicated above, EPA has conducted the

first five-year review and has

determined that the remedy selected for

Silver Mountain Mine remains

protective of human health and the

environment. For future five-year

reviews, EPA will review Ecology’s

annual reports on the operation and

maintenance at the site and as needed

perform a five-year review inspection.

Community Involvement

EPA published its Community

Relations Plan in December 1987, after

interviews with local residents and

officials. An information repository was

established at the Okanogan County

Courthouse and all of the documents

used to make the decision were placed

there before the final Record of Decision

was signed. All other reports and fact

sheets were sent to the repository as

they were completed. Those individuals

on the mailing list were informed by

fact sheet prior to construction activities

on-site. No public meetings have been

requested thus far.

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).

EPA, with the concurrence of Ecology,

believes that this criterion for deletion

has been met. Subsequently, EPA is

proposing deletion of this site from the
40786 Federal Register / Vol. 62, No. 146 / Wednesday, July 30, 1997 / Proposed Rules

NPL. Documents supporting this action

are available from the docket.

State Concurrence

The Washington Department of

Ecology concurs with the proposed

deletion of the Silver Mountain Mine

Superfund site from the NPL.

Dated: July 17, 1997.

Charles Findley,

Acting Regional Administrator, U.S. EPA

Region 10.

[FR Doc. 97–19940 Filed 7–29–97; 8:45 am]

BILLING CODE 6560–50–P

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric

Administration

50 CFR Part 226

[Docket No. 970715175–7175–01; I.D. No.

042997B]

RIN 0648–AG58

Designated Critical Habitat; Umpqua

River Cutthroat Trout

AGENCY: National Marine Fisheries

Service (NMFS), National Oceanic and

Atmospheric Administration,

Commerce.

ACTION: Proposed rule; request for

comments; and notice of public

hearings.

SUMMARY: NMFS proposes to designate

critical habitat for the Umpqua River

cutthroat trout (Oncorhynchus clarki

clarki) pursuant to the Endangered

Species Act of 1973 (ESA) to include:

The Umpqua River from a straight line

connecting the west end of the South

jetty and the west end of the North jetty

and including all Umpqua River

estuarine areas (including the Smith

River) and tributaries proceeding

upstream from the Pacific Ocean to the

confluence of the North and South

Umpqua Rivers; the North Umpqua

River, including all tributaries, from its

confluence with the mainstem Umpqua

River to Toketee Falls; the South

Umpqua River, including all tributaries,

from its confluence with the mainstem

Umpqua River to its headwaters

(including Cow Creek, tributary to the

South Umpqua River). Critical habitat

includes all waterways below

longstanding, natural impassable

barriers (i.e., natural water falls in

existence for over several hundred

years). Such areas represent the current

freshwater and estuarine range of the

listed species. The economic and other

impacts resulting from this proposed

critical habitat designation are expected

to be minimal.

DATES: Comments must be received on

or before September 29, 1997. Public

hearings on this proposed action are

scheduled for the month of August. See

SUPPLEMENTARY INFORMATION for dates

and times of public hearings.

ADDRESSES: Comments should be sent to

NMFS, Environmental and Technical

Services Division, 525 NE Oregon St.

Suite 500, Portland, OR 97232–2737.

See SUPPLEMENTARY INFORMATION for

locations of public hearings.

FOR FURTHER INFORMATION CONTACT:

Garth Griffin, NMFS, Environmental

and Technical Services Division, 525

NE Oregon St. Suite 500, Portland, OR

97232–2737, telephone (503/231–2005)

or Joe Blum, NMFS, 1335 East-West

Highway, Silver Spring, MD 20910,

telephone (301/713–2322).

SUPPLEMENTARY INFORMATION:

Background

On August 9, 1996, NMFS published

its determination to list Umpqua River

cutthroat trout (Oncorhynchus clarki

clarki) as endangered under the ESA (61

FR 41514). In its final listing

determination, NMFS concluded that all

cutthroat trout life history forms (i.e.,

anadromous, potamodromous, and

resident) should be included in the

listed Umpqua River cutthroat trout

Evolutionarily Significant Unit. This

conclusion was based on studies

conducted by Oregon Department of

Fish and Wildlife (ODFW) and others

which indicate that these life history

forms are not completely reproductively

isolated and, therefore, should be

considered a single ‘‘distinct population

segment,’’ under the ESA and NMFS’’

ESA species policy (See 61 FR 41516).

Historically, anadromous,

potamodromous, and resident cutthroat

trout likely occurred throughout the

Umpqua River basin. The current

freshwater distribution of anadromous

and potamodromous life forms is

thought to be limited primarily to the

mainstem, Smith, and North Umpqua

Rivers. Resident cutthroat trout appear

to remain broadly distributed

throughout the Umpqua River basin,

including areas of the South Umpqua

River not thought to support significant

anadromous cutthroat trout populations.

Section 4(a)(3)(A) of the ESA requires

that, to the maximum extent prudent

and determinable, NMFS designate

critical habitat concurrently with a

determination that a species is

endangered or threatened. On July 19,

1993, NMFS published a Federal

Register document (58 FR 38544)

soliciting information and data

regarding the present and historic status

of the Umpqua River cutthroat trout, as

well as information on areas that may

qualify as critical habitat. At the time of

the final listing, critical habitat was not

determinable, since information

necessary to perform the required

analyses was not available. NMFS has

determined that sufficient information

now exists to designate critical habitat

for this species. NMFS has considered

all available information and data in

making this proposal.

Definition of Critical Habitat

Critical habitat is defined in section

3(5)(A) of the ESA as ‘‘(i) the specific

areas within the geographical area

occupied by the species * * * on which

are found those physical or biological

features (I) essential to the conservation

of the species and (II) which may

require special management

considerations or protection; and (ii)

specific areas outside the geographical

area occupied by the species * * *

upon a determination by the Secretary

of Commerce (Secretary) that such areas

are essential for the conservation of the

species.’’ (See 16 U.S.C. 1532(5)(A)).

The term ‘‘conservation,’’ as defined in

section 3(3) of the ESA, means ‘‘ * * *

to use and the use of all methods and

procedures which are necessary to bring

any endangered species or threatened

species to the point at which the

measures provided pursuant to this Act

are no longer necessary.’’ (See 16 U.S.C.

1532(3)).

In designating critical habitat, NMFS

considers the following requirements of

the species: (1) Space for individual and

population growth, and for normal

behavior; (2) food, water, air, light,

minerals, or other nutritional or

physiological requirements; (3) cover or

shelter; (4) sites for breeding,

reproduction, or rearing of offspring;

and, generally, (5) habitats that are

protected from disturbance or are

representative of the historic

geographical and ecological

distributions of this species (See 50 CFR

424.12(b)). In addition to these factors,

NMFS also focuses on the known

physical and biological features

(primary constituent elements) within

the designated area that are essential to

the conservation of the species and may

require special management

considerations or protection. These

essential features may include, but are

not limited to, spawning sites, food

resources, water quality and quantity,

and riparian vegetation (See Id.).