DERR-2024-007692

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TABLE OF CONTENTS

I. INTRODUCTION 1
A. Scope of this First Five Year Review Report 2

II. SITE CHRONOLOGY 3

III. BACKGROUND 5
A. General History of the OUs 5
B. OU Specific History – Operational Background & Remedy 7
1. OU3 Butterfield Mine, Canyon & Creek, Herriman &Agricultural
Lands 7
a. OU3 Butterfield Mine 7
i. Remedy for Butterfield Mine 7
b. OU3 Butterfield Canyon & Creek 7
i. Remedy for Butterfield Canyon & Creek 8
c. OU3 Herriman Residential & Agricultural Lands 9
i. Remedy for Herriman Residential & Agricultural
Lands 9
2. OU6 Lark Waste Rock & Tailings 12
a. Remedy for OU6 12
i. Lark Waste Rock 13
ii. Lark Tailings 13
iii. Randolph Peterson Gate 14
iv. Bastian Ditch 14
v. Mascotte Ditch 15
vi. Midas Creek Silos area 15
vii. Mascotte Pond 15
viii. Southeast Area 16
ix. Lone Tree Area 16
3. OU18 Acid Mine Drainage 16
a. Utah Metals Tunnel and Utah Metals Tunnel Dump 16
i. Remedy for Utah Metals Tunnel and Utah Metals Tunnel
Dump 17
b. Other Tunnels on the Western Slope or the Crest of The Oquirrh
Mountains 18
i. Remedy for Other Tunnels 19

IV. REMEDIAL ACTIONS 20
A. OU3 Butterfield Mine, Canyon & Creek, Herriman Residential &
Agricultural Lands 20
B. OU6 Lark Waste Rock & Tailings, Ancillary Facilities 21
C. OU18 Acid Mine Drainage 21

V. PROGRESS SINCE LAST FIVE YEAR REVIEW 21

VI. FIVE YEAR REVIEW PROCESS 21
A. Administrative Components 21
ii
B. Community Involvement 23
C. Document Review 23
1. OU3 Butterfield Mine, Canyon & Creek, Herriman Residential &
Agricultural Lands 23
a. State Permits 23
b. Post Remediation Sampling 24
c. City of Herriman Institutional Controls Program 24
2. OU6 Lark Waste Rock & Tailings 27
a. Response Action Report 27
b. State Permits 27
c. Post Construction Sampling 27
3. OU18 Acid Mine Drainage 28
a. Post Construction Sampling 28
D. Data Review 28
1. OU3 Butterfield Mine, Canyon & Creek 29
2. OU3 Herriman Residential & Agricultural Lands 29
3. OU6 Lark Waste Rock & Tailings 29
E. Site Inspection 29
1. OU3 Herriman Residential & Agricultural Lands, Butterfield
Mine, Canyon & Creek 30
2. OU6 Lark Waste Rock & Tailings 31
a. Mascotte Tunnel and Bingham Tunnel 32
b. Lark Waste Rock 32
c. Lark Tailings 32
3. OU18 Acid Mine Drainage 32
F. Interviews 33

VII. TECHNICAL ASSESSMENT 33
A. OU3 Butterfield Mine, Butterfield Canyon & Creek, Herriman
Residential & Agricultural Lands 33
1. Question A – Is the remedy functioning as intended by the decision
documents? 33
a. Butterfield Mine, Canyon & Creek 33
b. Herriman Residential & Agricultural Lands 34
2. Question B – Are the exposure assumptions, toxicity data, cleanup
levels and remedial action objectives used at the time of remedy
selection still valid? 35
a. Butterfield Mine, Canyon & Creek 35
i. Changes in Standards and To Be Considers 35
ii. Changes in Exposure Pathways 36
iii. Changes in Toxicity, and other Contaminant Characteristics 37
iv. Changes in Risk Assessment Methods 37
v. Expected Progress Towards Meeting RAOs 37
b. Herriman Residential & Agricultural Lands 37
i. Changes in Standards and To Be Considers 38
ii. Changes in Exposure Pathways 38
iii. Changes in Toxicity, and other Contaminant Characteristics 39
iv. Changes in Risk Assessment Methods 39
v. Expected Progress Towards Meeting RAOs 39

iii
3. Question C – Has any other information come to light that could
call into question the protectiveness of the remedy? 39
4. Technical Assessment Summary 39
B. OU6 Lark Waste Rock & Tailings 40
1. Question A – Is the remedy functioning as intended by the decision
documents? 40
2. Question B – Are the exposure assumptions, toxicity data, cleanup
levels and remedial action objectives used at the time of remedy
selection still valid? 40
a. Changes in Standards and To Be Considers 41
b. Changes in Exposure Pathways 42
c. Changes in Toxicity, and other Contaminant Characteristics 42
d. Changes in Risk Assessment Methods 42
e. Expected Progress Towards Meeting RAOs 42
3. Question C – Has any other information come to light that could
call into question the protectiveness of the remedy? 42
4. Technical Assessment Summary 43
C. OU18 Acid Mine Drainage 43
1. Question A – Is the remedy functioning as intended by the decision
documents? 43
2. Question B – Are the exposure assumptions, toxicity data, cleanup
levels and remedial action objectives used at the time of remedy
selection still valid? 45
a. Changes in Standards and To Be Considers 45
b. Changes in Exposure Pathways 45
c. Changes in Toxicity, and other Contaminant Characteristics 46
d. Changes in Risk Assessment Methods 46
e. Expected Progress Towards Meeting RAOs 46
3. Question C – Has any other information come to light that could
call into question the protectiveness of the remedy? 46
4. Technical Assessment Summary 46

VIII. ISSUES 47
A. OU3 Butterfield Mine, Canyon & Creek, Herriman Residential &
Agricultural Lands 47
1. A Summery of issues for OU3 are given in the following table 47
B. OU6 Lark Waste Rock & Tailings 48
1. A summary of issues for OU6 are given in the following table 48
C. OU18 Acid Mine Drainage 48
1. A summary of issues for OU18 are given in the following table 48

IX. RECOMMENDATIONS AND FOLLOW-UP ACTIONS 49
A. OU3 Butterfield Mine, Canyon & Creek, Herriman Residential &
Agricultural Lands 49
1. Butterfield Mine 49
2. Butterfield Canyon & Creek 50
3. Herriman Residential & Agricultural Lands 51
4. A summary of recommendations for OU3 are given in the following
table 53
B. OU6 Lark Waste Rock & Tailings 55
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LIST OF ACRONYMS & DEFINITIONS

Agencies Collectively the U.S. Environmental Protection Agency Region VIII &
Utah Department of Environmental Quality
AOC Administrative Order on Consent
ARARS Applicable or Relevant and Appropriate Requirements
CAA Clean Air Act
CERCLA Comprehensive Environmental Response, Compensation, and Liability
Act
CFR Code of Federal Regulations
COC(s) Contaminant of Concern(s)
CWA Clean Water Act
DERR Utah Division of Environmental Response & Remediation
DOGM Utah Division of Oil, Gas and Mining
DWQ Utah Division of Water Quality
EPA United States Environmental Protection Agency Region VIII
Facilities or facilities Operational, waste disposal, or waste impacted portions of an OU
gpm Gallons per minute
HAG Herriman Agricultural Ground
IC(s) Institutional Control(s)
Kennecott Kennecott Utah Copper Corporation
NAMS North American Mine Services
NCP National Oil and Hazardous Substances Pollution Contingency Plan
NESHAP National Emission Standards for Hazardous Air Pollutants
NPL National Priorities List
mg/kg Milligram per Kilogram
mg/l Milligram per litter
O&M Operation and Maintenance
O,M&R Operation, Maintenance & Replacement
OSHA Occupational Safety and Health Act
OSWER Office of Solid Waste and Emergency Response
OU Operable Unit
PA/SI Preliminary Assessment/Site Investigation
RA Remedial Action
RAO(s) Remedial Action Objective(s)
RCRA Resource Conservation and Recovery Act
RD Remedial Design
ROD Record of Decision
RP Responsible Party
SARA Superfund Amendments and Reauthorization Act
SAS Superfund Alternative Sites
UU/UE Unrestricted Land Use/Unrestricted Exposure (standard)
UDEQ Utah Department of Environmental Quality
UPDES Utah Pollution Discharge Elimination System

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EXCUTIVE SUMMARY

Utah Department of Environmental Quality (UDEQ) has conducted the first five-year review of the
remedial actions implemented at Operable Units (OUs) No. 3 (Butterfield Mine & Canyon/Creek,
Herriman Residential & Agricultural Lands), No. 6 Lark Waste Rock & Tailings, No. 7 South Jordan
Evaporation Ponds, No. 17 Bastian Sink, and No. 18 (Acid Mine Drainage, including Tunnel & Dump
sites, in Tooele County) of the Kennecott South Zone site, located in Herriman, unincorporated Salt Lake
County and in unincorporated Tooele County, Utah. The review was conducted from June 2008 through
March 2009. The results of the five-year review indicate that portions of the various remedies are
protective of human health and the environment.

· Operable Unit No. 3 is a large operable unit comprised of Butterfield Mine, Canyon & Creek and
the Herriman Residential & Agricultural Lands. For the most part the areas comprising OU3
were found to be protective of human health based on current land use. The surface soils on the
affected properties were found to be stable. Some previously capped areas within Butterfield
Canyon were recognized during this review. Development activities within the Herriman
Residential & Agricultural Lands were largely in areas of non-impact within the City of
Herriman’s jurisdiction (but some notable large developments on impacted agricultural lands
were being overseen by the City). The selected remedy of institutional controls (ICs) was found
not to be universally applied to portions of OU3 and pertinent ARARS were noted not to have
been listed in the 2001 Kennecott South Zone Record of Decision (ROD). Some mapping, ICs
development and ARARs incorporation were recommended as part of this review.

· Operable Unit No. 6 is a large operable unit comprised of Lark Waste Rock & Tailings and
ancillary facilities. For the most part the areas comprising OU6 were found to be protective of
human health based on current land use. The surface soils on the affected properties were found
to be stable. UDEQ assessed that the Lark Waste Rock removal action was successful to reach
the cleanup goals of 1000 mg/kg lead and 100 mg/kg arsenic (even though UDEQ noted the lack
of a risk assessment, these were the cleanup goals selected under the Administrative Order on
Consent (AOC)). UDEQ also assessed that soils with elevated lead and arsenic above potentially
applicable unrestricted land use/unrestricted exposure standards for lead and arsenic still exist on
site at Lark Tailings and ancillary facilities. As part of this five-year review it has been
recommended that the Lark Tailings and ancillary facilities be mapped and appropriate
institutional controls be developed with the applicable land owners.

· Operable Unit No. 7 South Jordan Evaporation Ponds, Operable Unit No. 17 Bastian Sink &
other ancillary facilities were observed to be in a stable condition and supportive of current land
use (i.e. residential, commercial, recreational). The removal work performed by Kennecott Land
in 2006-2007 was found to have attained the residential land use standards (700 mg/kg lead and
100 mg/kg arsenic, respectively) at OU7 and OU17. Except for the new work to review, the
response actions at the Bastian Ditch, Pond A0 & F, and the Evaporation Ponds Canal and
Tailwater Ditches, and to oversee the implementation of removal actions along the historical rail
corridors associated with OU1, no further response action is being planned at this time. Since no
waste is left in place above the residential standards established by the Agencies, no further five-
year reviews will be necessary and protectiveness statements were not needed for this five-year
review. For further explanation see Appendix J.

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· Operable Unit No. 18, Acid Mine Drainage (Tunnels & Dump sites) in Tooele County was
determined to be stable and the selected remedies were deemed to still be protective. The
primary site of concern in this Operable Unit is the Utah Metals Tunnel and Utah Metals Tunnel
Dump site in Middle Canyon, Tooele County. The water from the tunnel is now directed from
the portal of the dump (via pipe) to the base of the Dump’s western embankment. Revegetation
efforts were found to be progressing to cover the dump surface. No waste rock was found in the
Middle Creek channel. Management of the Utah Metals Tunnel and Utah Metals Tunnel Dump is
recommended to be continued by Kennecott Utah Copper Corporation under the pending Site
Wide Management Plan for wastes left in place.

Areas of concern (i.e. issues) include: (1) Limited sampling data to independently verify the condition of
post remediated surfaces on properties within the City of Herriman boundaries, (2) No ICs program
implemented by the planning and engineering divisions of Salt Lake County to facilitate the management
of soils during proposed land use changes, (3) No formal federal and state Applicable or Relevant and
Appropriate Requirements (ARARs) to cover soil removal activities on Herriman Residential &
Agricultural lands, (4) Soils above potentially applicable Unrestricted Land Use/Unrestricted Exposure
(UU/UE) standards for lead and arsenic in OU6 with no ICs to control changes in land use, (5) No formal
federal and state ARARs to ensure proper management of soils within OU6, (6) Site management reports
for the Utah Metals Tunnel and Utah Metals Tunnel Dump have been infrequently provided to UDERR,
(7) Areas with soils exceeding potentially applicable unrestricted land use/unrestricted exposure standards
for lead and arsenic buried or near the surface.

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FIVE-YEAR REVIEW SUMMARY FORM

SITE IDENTIFICATION

Site name (from WasteLAN): Kennecott South Zone

EPA ID (from WasteLAN): UTD000826404

Region: 8

State: UT

City/County: City of Herriman, City of South Jordan, Salt Lake
County & Tooele County, Utah

SITE STATUS

NPL status: Proposed Final Deleted Proposal W ithdrawn

Remediation status (choose all that apply): Under Construction Operating Complete

Multiple OUs? YES NO

Construction completion date: N/A

Has site been put into reuse? YES NO

REVIEW STATUS

Reviewing agency: EPA State Tribe Other Federal Agency

Author name: Douglas Bacon

Author title: Remedial Project
Manager/Environmental Scientist

Author affiliation: UDEQ

Review period: June 2008 to March 2009

Date(s) of site inspection: June 26, 2008 and September 25, 2008

Type of review: Statutory Policy ( Post-SARA Pre-Sara NPL-Removal only
Non-NPL Remedial Action Site NPL State/Tribe-lead Regional Discretion)
Review number: 1(first) 2 (second) 3 (third) Other (specify)

Triggering action:
Actual RA Onsite Construction Actual RA Start at OU # ___ Construction Completion
Previous Five-Year Review Report Other (specify): UDEQ plan entitled Five Year Review Schedule
& Operable Unit Inclusion (dated February 14, 2008) establishes triggers for five-year review.
Triggering action date (from WasteLAN):

Due date (SCAP GOAL): 04/30/09

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Five Year Review Summary Form
Issues:

The following issues affect current protectiveness of the selected remedies at the noted operable
units:

· (OU3) Up-gradient waste rock piles located in the side drainages of Butterfield Canyon (if left uncontrolled) could
by erosion and migration potentially cause a reintroduction of waste rock into the remediated areas of Butterfield
Canyon.

· (OU3) Trash and general refuse debris was located around Eva’s Pond, a small wetland pond once used as a
debris catch basin during removal actions in Butterfield Canyon and Creek.

· (OU3) At the confluence of Saints Rest and Yosemite drainages (with Butterfield Canyon) there are buried soils
that exceed potentially applicable unrestricted land use/unrestricted exposure (UU/UE) standards for lead and
arsenic.

· (OU3) ICs program by the City of Herriman is being revised. UDEQ has developed some concerns during a
review of the proposed procedures. If the revisions by the City of Herriman lessen the protectiveness of the ICs,
the remedy may be at risk.

· (OU6) In the areas of the Lark Tailings reclamation work and the noted ancillary sites there is the potential for
materials (soils or mixed soils/tailings) with lead and arsenic above potentially applicable UU/UE standards for
lead and arsenic.

· (OU18) A map of the Utah Metals Tunnel and Utah Metals Tunnel Dump site has not been submitted as of yet by
Kennecott Utah Copper Corporation. The required work under the North Zone & South Zone ROD of 2002 has
not been completed, work plans are pending.

· (OU18) Site management annual inspection reports from Kennecott Utah Copper Corporation for the Utah Metals
Tunnel and Utah Metals Tunnel Dump have not been successively submitted to UDEQ since the selection of the
remedial action, listed in the North Zone & South Zone ROD of 2002.

The following issues could effect current protectiveness of selected remedies, at the noted operable
units:

· (OU3) At the confluence of Saints Rest and Yosemite drainages (with Butterfield Canyon) there are buried soils
that exceed potentially applicable unrestricted land use/unrestricted exposure standards for lead and arsenic.

· (OU3) Residential Lands in the City of Herriman had a removal action performed upon them, and in some
locations elevated concentrations of lead and arsenic may still exist under an 18 inch soil cover. Mapping and
institutional knowledge of these Residential Lands is limited.

· (OU3) Pasture lots or extended lots at residential properties were not universally addressed during the removal
work and subsequently could have elevated lead and arsenic concentrations in the surface and near surface soils.
Un-controlled land use changes could cause a release or a risk of exposure to the public.

· (OU3) The selected remedy (i.e. ICs program) for the City of Herriman to oversee the management of soils with
elevated concentrations of lead and arsenic (above certain land use standards) does not require independent
verification (by the overseeing authorities) that the post remediated surface meets the land use standards listed in
the 2001 Record of Decision. ICs program is a self certification program.

· (OU3) No ARARs were listed in the ROD for the ICs program, required as the remedy for the Community of
Herriman.

· (OU3) There is no ICs program that could be verified as implemented by the engineering and planning divisions of
Salt Lake County to oversee the redevelopment of residential or agricultural properties (within the County’s
jurisdiction) around the City of Herriman.

· (OU3) Some recent re-development projects at some of the agricultural properties in the City of Herriman may
have left soils on site with elevated lead and arsenic concentrations, concentration is currently unknown.

· (OU6) In the areas of the Lark Tailings reclamation work and the noted ancillary sites there is the potential for
materials (soils or mixed soils/tailings) with lead and arsenic above potentially applicable UU/UE standards for
lead and arsenic.

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Five Year Review Summary Form
Recommendations and Follow-Up Actions:

For issues that do not affect current protectiveness:

· (OU3) During subsequent five-year reviews, compliance by Kennecott Utah Copper Corporation with their
UPDES, Stormwater and Groundwater Protection permits should be reviewed.

· (OU3) Salt Lake County Parks & Recreation and Public Works departments should be notified about trash build-
up in certain locations in Butterfield Canyon (i.e. Eva’s pond) and suggest they notify local service organization
(i.e. Boy Scout of America, Girl Scouts of America) about canyon cleanup service project opportunities.

· (OU3) The Agencies (UDEQ & EPA) should adopt UU/UE standards for lead and arsenic, develop an ICs
program coordinating with Kennecott and Salt Lake County, perform an ARARs analysis and continue to perform
five year reviews for the Butterfield Canyon confluences with Saints Rest and Yosemite drainages.

· (OU3) UDEQ should provide the City of Herriman with comments concerning information and procedural gaps
observed by UDEQ in the proposed revised ICs program.

· (OU6) The Agencies should adopt UU/UE standards for lead and arsenic, develop an ICs program coordinating
with Kennecott and Salt Lake County, perform an ARARs analysis and continue to perform five year reviews for
the Lark Tailings area and the ancillary facilities at OU6.

· (OU18) As part of the Site Wide Management Plan for wastes left in place (a plan to be submitted by Kennecott
Utah Copper Company as part of the pending North Zone & South Zone Consent Decree) a map for the Utah
Metals Tunnel and Utah Metals Tunnel Dump site should be submitted as part of the management plan.

· (OU18) As part of the Site Wide Management Plan for wastes left in place (a plan to be submitted by Kennecott
Utah Copper Company as part of the pending North Zone & South Zone consent decree) a schedule for annual
inspection reports for the Utah Metals Tunnel and Utah Metals Tunnel Dump should be included.

For issues that could affect current protectiveness:

· (OU3) The Agencies should adopt UU/UE standards for lead and arsenic, develop an ICs program coordinating
with Kennecott and Salt Lake County, perform an ARARs analysis and continue to perform five year reviews for
the Butterfield Canyon confluences with Saints Rest and Yosemite drainages.

· (OU3) UDEQ could assist the City of Herriman to verify they have pertinent records for the residential properties
that have elevated lead and arsenic concentrations above specified land use standards listed in the 2001 Record
of Decision, below an existing 18 inch soil cover or on in the surface and near surface soils of pasture lots &
extended backyards.

· (OU3) UDEQ could verify with the City of Herriman that they are in receipt of records denoting the location of
pasture lots and extended “backyards” that did not undergo a removal action to address elevated concentrations
of lead and arsenic. UDEQ will verify that land use on these areas has not changed since the selection of the
remedial activities and implementation of response work, and ensure that development on these areas will be
overseen by the City of Herriman’s ICs program.

· (OU3) On a limited basis (and after acquisition of access agreements) the Agencies could screen biased locations
on properties that have recently undergone a remedial action as part of development, pursuant to the ICs program
of the City of Herriman.

· (OU3) The Agencies should do a reanalysis of the ARARs for the selected remedy (ICs) for the Community of
Herriman.

· (OU3) The Agencies will coordinate outreach to the engineering and planning divisions of Salt Lake County to
negotiate and assist them with development of an ICs program they can use to oversee the proper management
of soils with elevated lead and arsenic above applicable land use standards established in the September 2001
Kennecott South Zone ROD, during future redevelopment of residential and agricultural lands within their
jurisdiction around the City of Herriman.

· (OU6) The Agencies should adopt UU/UE standards for lead and arsenic, develop an ICs program coordinating
with Kennecott and Salt Lake County, perform an ARARs analysis and continue to perform five year reviews for
the Lark Tailings area and the ancillary facilities at OU6.

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Five Year Review Summary Form
Protectiveness Statement:

· OU3 Butterfield Mine, Butterfield Canyon & Creek, Herriman Residential and Agricultural Lands (City of
Herriman and Salt Lake County):

The remedy for OU3 is not protective because: (1) potential redevelopment (i.e. change in land use) on portions of
the operable unit is not managed through an ICs program, (2) the current ICs program in the City of Herriman is a
“self certification” program which lacks independent verification of statements made by building permit applicants
that a site is protective for the intended land use, (3) there are no listed ARARs for the selected remedy.

· OU6 Lark Waste Rock & Tailings and ancillary facilities: The remedy for the Lark Waste Rock removal project is
protective of human health and the environment for current (industrial, open space) and potentially applicable future
land use (open space, agricultural, residential) because the response work removed materials above the cleanup
goals. The remedy for Lark Tailings (re-grading and cover) and the ancillary facilities (some characterization, some
hotspot removals) is protective of human health and the environment for current land use applications (i.e. open
space and agricultural).

Development of ICs for the Lark Tailings area and ancillary facilities will ensure that if (in the future) the land use
changes, the soils at these two sites are investigated to determine if they support the intended land use.

· OU18 Acid Mine Drainage: The remedy at Operable Unit 18 is protective of human health and the environment.
Source controls are in place at the Water Supply Tunnel and Water Supply Tunnel Dump and are being maintained
and operated in compliance with the September 2002 North Zone & South Zone ROD. These controls are being
monitored by Kennecott. The response action (stabilization of the waste rock in the dump and prevention of erosion)
remains intact and there were no new impacts to the remediated area.

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1
FIRST FIVE YEAR REVIEW
BUTTERFIELD MINE & CANYON/CREEK, HERRIMAN
RESIDENTIAL & AGRICULTURAL LANDS, LARK WASTE ROCK &
TAILINGS, SOUTH JORDAN EVAPORATION PONDS, BASTIAN
SINK, ACID MINE DRAINAGE & DUMP SITES IN TOOELE COUNTY
KENNECOTT SOUTH ZONE
OUs 3, 6, 7, 17 &18

I. INTRODUCTION

The purpose of the five-year review is to determine whether the remedy at a site is protective
of human health and the environment. The methods, findings and conclusions of reviews are
documented in five-year review reports. In addition, five-year reviews reports identify issues
found during the review, if any, and identify recommendations to address them.

UDEQ is preparing this five-year review report pursuant to CERCLA §121 and the National
Contingency Plan (NCP). CERCLA §121 states:

If the President selects a remedial action that results in any hazardous substances,
pollutants, or contaminants remaining at the site, the President shall review such
remedial action no less often than each five years after the initiation of such remedial
action to assure that human health and the environment are being protected by the
remedial action being implemented. In addition if upon such review it is the judgment of
the President that action is appropriate at such site in accordance with section [104] or
[106], the President shall take or require such action. The President shall report to the
Congress a list of facilities for which such review is required, the results of all such
reviews, and any actions taken as a result of such reviews.

UDEQ interpreted this requirement further in the NCP; 40 CFR §300.430(f)(4)(ii) states:

If a remedial action is selected that results in hazardous substances, pollutants, or
contaminants remaining at the site above levels that allow for unlimited use and
unrestricted exposure, the lead agency shall review such action no less often than every
five years after the initiation of the selected remedial action.

The UDEQ conducted the five-year review of the remedies or response work implemented at
Operable Units 3, 6, 7, 17, & 18 of the Kennecott South Zone site, located in Salt Lake and
Tooele Counties, Utah. This review was conducted by the Utah Department of
Environmental Quality, UDEQ, Division of Environmental Response & Remediation, DERR,
project manager (Mr. Douglas Bacon) on behalf of the United States Environmental
Protection Agency Region VIII, EPA, (Rebecca Thomas, Remedial Project Manager). The
review ran from June 2008 through March 2009. This report documents the results of the
review.

This is the first five-year review for Operable Units No. 3, 6, 7, 17 & 18 of the Kennecott
South Zone site. The triggering action for this statutory review was the completion of
remedial action for OU3, 6, & 7 under the remedial design/remedial action consent decree of
January 2003 and the agreed upon deferment by EPA Region VIII and UDEQ in the
2
document entitled Five Year Review Schedule & Operable Unit Inclusion dated February 14,
2008.

A. Scope of this First Five Year Review Report

The Kennecott Sites, Kennecott North Zone and Kennecott South Zone, were divided
into 24 operable units (OUs). Later, two of the operable units were addressed as separate
sites (Old Cobalt Ponds Removal Action and International Smelter and Refining NPL
Site, OUs 20 & 21). Under the UDEQ document entitled Five Year Review Schedule &
Operable Unit Inclusion dated February 14, 2008, EPA and UDEQ agreed to a
reorganization of the operable units requiring a five-year review, and the timing for such.
A summary of the operable units requiring a five-year review and triggers for such is
given as follows (please note per agreement between EPA and UDEQ reviews are slated
for performance and completion within a calendar year cycle, unless subsequently agreed
upon by the parties to change):

Table 1 – Operable Units and Five Year Review Triggers
Operable Unit
Groups/Area
Operable
Units
Five Year Trigger Date of First
or Subsequent
Five Year
Reviews
No. 1 - South Zone
Bingham Creek Area
and operational areas
1, 5, 10,
11, 24
First Five Year Review
completed in June 2004
June 2009
No. 2 - South Zone,
SW Jordan Valley
ground water plumes
and Bingham Canyon
underflow
2, 16 Remedial action Consent
Decree May 2008
December
2013
No. 3 - South Zone
Butterfield Creek area
and Tooele County
areas
3, 18 † Remedial Action Consent
Decree 2003, and agreed upon
deferment of the FYR start
September
2009
No. 4 – North Zone
operational areas and
AOC removal sites
8, 13, 14,
15, 19, 22,
23,
Bingham
Magna
Ditch
Remedial Design and Remedial
Action start still in progress or
implemented, Design and
Action to be finalized by
Consent Decree
Not Scheduled
/ To Be
Determined *
* Pursuant to the UDEQ document entitled Five Year Review Schedule & Operable Unit
Inclusion dated February 14, 2008, EPA Region VIII and UDEQ agreed to defer
scheduling until the Remedial Design (RD) and Remedial Action (RA) activities are
completed during the negotiations of the North Zone & South Zone consent decree for
said action.
† Pursuant to EPA Region VIII Enforcement requests, UDEQ included Operable Units
No. 6, 7, & 17 in the five-year review and report for group No. 3 (midway through the
review).
Pursuant to the UDEQ document entitled Five Year Review Schedule & Operable Unit
Inclusion dated February 14, 2008, EPA Region VIII and UDEQ agreed to defer the five-
3
year review for Group No. 2 until five years from the RDCD date (a document which
included the acceptance of the remedial action completion report).

Subsequent to the initiation of negotiations on the North Zone- South Zone remedial
design/remedial action consent decree, UDEQ investigated reports of soils exceeding
unrestricted land use/unrestricted exposure (UU/UE) standards capped or left at the
surface in Operable Units No. 3, 6, 7 & 17. Though the agency agreement dated
February 14, 2008 noted OU6, OU7 & OU17 did not need a five-year review, EPA and
UDEQ agreed that this five-year review would investigate the noted reports of capped
soils.

Though outside the normal process, this report covers the closure determinations for
Operable Units No. 7 & No. 17 in Appendix J of this report. The following chapters may
allude periodically to OU7 & OU17 but for the more detail description on the closure
recommendations, please refer to Appendix J.

II. Site Chronology

OUs No. 3, 6 & 18 of the Kennecott South Zone site were addressed at separate times during
the progression of the CERCLA investigations. As such, the chronology of each OU is
provided in separate tables below.

As requested by EPA Region VIII – Enforcement, UDEQ included a shortened review of
OUs 7 & 17, simply to acknowledge the formal remedial action at these operable units was
completed (refer to Appendix J). This was done to facilitate the completion of the Kennecott
North Zone & South Zone Consent Decree. Per advice from Region VIII, this shortened
review did not require the traditional categories of a five-year review report, hence the
chronology of events at these two OUs is not provided in this Chapter.

Table 2 – Chronology of actions at OU3 Butterfield Mine (source, Sept. 2001 Kennecott
South Zone ROD for OU3, 6, 7)
Date Activity
1991 Preliminary Assessment and Site Investigation study
1991 Administrative Order on Consent for removal project, Butterfield
Mine Waste Rock (including Castro Gulch Waste Rock)
1991 – 1993 Removal work implementation
1993 Final removal report received
1993 Final site inspection
1994 Close out of Administrative Order
2001 Record of Decision
2003 Remedial Design Consent Decree entered
2008 Site Inspection for Five Year Review

Table 3 – Chronology of action at OU3 Butterfield Canyon and Creek (source, Sept.
2001 Kennecott South Zone ROD for OU3, 6, 7)
Date Activity
1994 Assessment of on-site historic facilities
1997 Administrative Order on Consent for removal project to address
tailings and waste rock, establishment of sediment traps and
implement monitoring of creek.
4
Pending Final site inspection
Pending Close out of Removal Order
2001 Record of Decision
2003 Remedial Design Consent Decree entered
2008 Site Inspection for Five Year Review

Table 4 – Chronology of action at OU3 Herriman Residential and Agricultural Lands
(source, Sept. 2001 Kennecott South Zone ROD for OU3, 6, 7)
Date Activity
1994 Initial assessment
1996-97 Removal assessment
1997 Removal project for Herriman Residential Soils, Administrative Order
on Consent
1998 Amendment to Administrative Order on Consent to cover another two
years of removal activities
1998 Preliminary assessment of Herriman agricultural lands
1999 Assessment of Herriman agricultural lands
Pending Close out of removal project
2001 Record of Decision
2003 Remedial Design Consent Decree entered (did not include fund lead
portion of the project)
2008 Site Inspection for Five Year Review

Table 5- Chronology of actions at OU6 Lark Waste Rock & Tailings
Date Activity
1986 CERCLA Preliminary Assessment and Site
Investigation for State Motorcycle Park and for Lark
Tailings determined the existence of elevated
concentrations of hazardous substances in the soils of
the sites.
1988 Kennecott cancels lease with Herriman Irrigation Co. for
use of Bingham Tunnel water. State had expressed
concern that the water quality was not good enough for
irrigation purposes.
1989 Kennecott (or State) cancels the lease for the State
Motorcycle Park due to fugitive dust problems.
1991 Site wide CERCLA Consent Decree negotiations begin
with EPA, UDEQ and Kennecott. Listing activities put
on hold.
1993 EPA approves Work Plan for Lark area and cleanup
begins with oversight by EPA and UDEQ.
1994 UDEQ conducts study of all watersheds in the area.
Included in this study were Midas Creek and Copper
Creek. These are similar to PA/SI investigations.
1994 Kennecott begins study of all historic facilities on their
property including: Mascotte Pond, Copper Gulch,
Midas Silo, and Randolph Peterson Gate. These are
similar to PA/SI investigations.
1995 Cleanup work completed on first phase of Lark
Removal.
5
1995 Parties reach agreement to continue cleanups under the
provisions of a Memorandum of Understanding.
Kennecott agrees to continue cleanups; EPA and UDEQ
agree to take no further action regarding listing of the
site.
1998 Administrative Order on Consent is signed by EPA and
Kennecott to cover previous cleanup activities in the
Lark area.
1998 Site is expanded to include cleanup of nearby historic
facilities including Copper Creek, Mascotte Pond, Midas
Silo, Mascotte Tailings, and Lone Tree.
1998 Final report and all amendments received.
1995, 1998 Final site inspections.
1998 Administrative Order closed out.
2001 Record of Decision
2003 Remedial Design Consent Decree entered

Table 6- Chronology of actions at OU18 Utah Metals Tunnel and Dump, Other Tunnels
and Dumps
Date Activity
1993 - 1995 Ecological risk assessment sample collections in Pine
Canyon and along the crest of the Oquirrh Mountains.
1995 Site investigation (grab samples of soil, waste rock,
water) of the Utah Metals Tunnel Dump, and Bingham
West Dip Tunnel.
2000 – onward Routine monitoring of water quality under the existing
UPDES permit for the Pine Canyon area.
2001 Relaxed slopes of the Utah Metals Tunnel Dump,
Stabilized Middle Canyon Creek channel, and
Revegetated the Utah Metals Tunnel Dump.

III. Background

A. General history of the OUs

Cleanups began in and around Butterfield Mine (Kennecott South Zone OU3) from 1991
to 1993 to address waste rock (Butterfield Waste Rock Site No. R2, AOC CERCLA VIII-
91-18). Assessment and cleanup of tailings from historical mill operations in Butterfield
Canyon (near the confluences of Yosemite and Saints Rests drainages) was initiated
around 1997 (Butterfield Canyon Site, SSID No. 08-R2, AOC CERCLA VIII-97-09).
Pursuant to the removal actions in the Canyon monitoring of Butterfield Creek was
undertaken to assess the lead and arsenic concentration in the Total Suspended Solids
load of Butterfield Creek for 4 years. This monitoring ceased in 2001 with agreement by
UDEQ (on behalf of EPA).

Characterization/removal action was conducted on 85 residential lands in the City of
Herriman from 1997 to 1999. In some cases the residential cleanup left elevated
concentrations of lead and arsenic at depth under a minimum 18 inch soil cover.
Characterization of agricultural lands in Herriman was performed from 1998 to 1999.
These characterization and cleanup actions were pursued under Administrative Orders on
6
Consent (AOCs) negotiated between EPA and the responsible party (RP), Kennecott
Utah Copper Corporation (Kennecott). Later, to ensure proper management of soils with
elevated concentrations of lead and arsenic on agricultural properties (as well as the
residential properties with contaminants of concern left at depth) during future
redevelopment activities, an institutional controls (ICs) only Record of Decision (ROD)
was issued for OU3 by EPA in September, 2001.

Response action (i.e. characterization, regrading and removal work) was performed in
and around OU6 Lark Waste Rock and Tailings, and the ancillary facilities to the site,
from 1993 to 1994 to address waste rock and tailings left at the site (Administrative
Order on Consent Docket CERCLA VIII-98-09). The waste rock removal project
addressed waste rock from the drilling of on-site tunnels or other mining operations with
a lead and arsenic concentration greater than 1000 mg/kg and 100 mg/kg respectively.
After characterization efforts, the area of Lark Tailings (sourced to the reworking of
existing mill tailings by Ohio Copper Company) was re-graded and covered. Ancillary
facilities in OU6 received some characterization and some soil removal actions.

Response action (i.e. characterization, removal, and consolidation work) was performed
in and around the South Jordan Evaporation Ponds (Kennecott South Zone OU7) and the
Bastian Sink (Kennecott South Zone OU17) from 1994 through 1995. Initial
characterization and removal work at OU7 was performed under an Administrative Order
on Consent Docket No. CERCLA-VIII-94-18. The early response work left consolidated
sulfate sludge in the two capped ponds onsite, which were subsequently removed by
Kennecott Land from 2006 to 2007. Kennecott Land’s response work was reported to
and approved by the Agencies in December 2007.

Initial characterization of the Bastian Sink (OU17) was performed under Unilateral
Administrative Order Docket No. CERCLA-VIII-93-06. Subsequent removal action in
OU17 was performed by Kennecott Land from 2006 to 2007. Kennecott Land’s response
work was reported too and approved by the Agencies in December 2007. Please refer to
Appendix J for the substantive discussion of OU7 & 17.

Pursuant to initial characterization efforts overseen by UDEQ, Kennecott assessed the
nature and extent of contamination (if any) at the various tunnels, adits and dumps
existing along the Oquirrh Mountains front, in Tooele County from 1996 to 2000. The
Utah Metals Tunnel Dump (waste rock with elevated lead concentrations) underwent a
remedial effort to relax the slopes, stabilize the drainage channel and revegetate the
Dump slopes in 2001 pursuant to a negotiated work plan under the Environmental On-
site and Off-site Assessment program. Further reclamation work was pursued by
Kennecott in 2006 and 2007.

In general, cleanups began in and on the operable units of the Kennecott South Zone (i.e.
OU3, OU6, OU7 and OU17) as removal actions; OU18 was handled initially as a
preliminary assessment/site investigation activity. Concurrent with these actions, EPA
began negotiations with Kennecott on a then-novel concept involving cleaning up mining
wastes without listing the site on the NPL. In order to streamline the responses, most of
the cleanups at the site were performed using the removal authorities of CERCLA, under
the provisions of AOCs as noted above. This approach was called at the time an
Enforcement Pilot. More recently, sites where this approach has been used have been
called non-NPL sites, NPL equivalent, NPL-alternative sites or Superfund Alternative
Sites (SAS).
7

One of the principal concepts used by EPA and UDEQ for management of these cleanups
was that the responses would be equivalent to the responses which would have been
required had the site been listed on the NPL. This concept included quality of the
cleanups, risk assessments, and community involvement. In all cases, the requirements of
CERCLA and the NCP for response at NPL sites was achieved or exceeded. There was a
strong commitment to community involvement as well.

B. OU Specific History – Operational Background & Remedy

1. OU3 Butterfield Mine, Canyon & Creek, Herriman Residential & Agricultural
Lands: OU3 is composed of several subunits.

a. Butterfield Mine: The Butterfield Mine is located about 2.5 miles up-gradient of
the mouth of the Butterfield Canyon. Waste rock from the Mine was deposited in
the bottom and along the sides of the canyon. Waste rock was found on 14 acres,
amounting to about 1.4 million tons. The Butterfield Mine adit has a flow which
discharges into Butterfield creek. It has a Utah Pollution Discharge Elimination
System (UPDES) permit. Butterfield Creek runs through the site.

As part of the removal work, a temporary sedimentation pond was installed
downstream along Butterfield Creek to trap construction debris. Because the
pond attracted wildlife and a diversity of wetland plants the pond was left after
construction. By reference, under the project the pond has been called “Eva’s
Pond”. The Butterfield Mine Tunnel portal still exists on site and still discharges
water drained from the mining shaft and interconnecting tunnel workings. As
noted above, the discharge from the tunnel is covered by a UPDES permit. A
Salt Lake County road, which transects the site, was reconstructed after the
removal of the waste rock, and is only open in the summer.

i. Remedy for Butterfield Mine: The removal action for Butterfield Mine
addressed 14.23 acres of waste rock deposited approximately 2.5 miles up
Butterfield Canyon, on the eastern slopes of the Oquirrh Mountains in Salt
Lake County. The work was conducted by Kennecott under the supervision
of EPA. Approximately 1.4 million tons of waste rock with a maximum lead
and arsenic concentration of 13,900 mg/kg (milligrams per kilogram) and
501 mg/kg (respectively) and a mean concentration of lead and arsenic of
6643 mg/kg and 327 mg/kg (respectively) were removed and placed in a
repository in Castro Gulch behind the storm water collection system
(“Eastside Collection System”). Post-removal surface sampling documented
a maximum lead and arsenic concentration of 550 mg/kg and 150 mg/kg
(respectively) and a mean lead and arsenic concentration of 143 mg/kg and
31 mg/kg (respectively).

b. OU3 Butterfield Canyon and Creek: Also in the Butterfield Canyon area were
deposits of tailings left by early milling operations in the Canyon. Tailings were
observed in the confluence area of Saints Rests and Butterfield Creek drainages,
and in the confluence area of Yosemite and Butterfield Creek drainages. The
tailings were deposited on both sides of Butterfield Creek. The tailings found at
the site amounted to 25,050 cubic yards. Within and up-gradient of Butterfield
Canyon and its drainage, are the locations of several mining and milling
8
operations and waste deposits. These include: Revere Mill, Yosemite Mill,
Brooklyn Mill, Holt Mill, Queens Mine and Mill, Blackjack Gulch Mines, St.
Joes Mine, Yosemite Gulch Mines, Saints Rest Mines.

i. Remedy for Butterfield Canyon and Creek: The removal action in Butterfield
Canyon addressed approximately 5 acres, located between the mouth of the
Canyon and the site of the Butterfield Mine, and some of the side canyon
drainages (i.e. Queen, Olson, Castro, Yosemite, Saints Rest, Black Jack and
St. James). During removal a number of artifacts dating to early mine
activities were unearthed and a number of historic milling operations were
addressed. Approximately 25,050 cubic yards of tailings material was
removed to the Bluewater Repository by Kennecott with supervision from
EPA. The tailings material removed (from the Yosemite and Saints Rest
Gulches at their confluence with Butterfield Canyon) had a maximum lead
and arsenic concentration of 65,900 mg/kg and 819 mg/kg (respectively), and
a mean lead and arsenic concentration of 12,400 mg/kg and 136 mg/kg
(respectively). Post removal surfaces were analyzed and shown to have a
maximum lead and arsenic concentration of 1420 mg/kg and 51 mg/kg
(respectively) and a mean lead and arsenic concentration of 427 mg/kg and
18.2 mg/kg (respectively). Removal actions in the Saints Rest and
Butterfield Canyon drainage confluence areas on average removed 3 feet of
mixed material (tailings and soils); similar action in the area of Yosemite and
Butterfield Canyon addressed 1 to 2 feet of mixed material (tailings and
soils). Both removal areas were brought back up to grade with on average an
18 inch soil cover, but in some places even thicker.

Other historic facilities investigated in the canyon (i.e. located and
characterized, located and found buried by the up-gradient waste rock piles,
or located, characterized and removed) included the Revere Mill, Yosemite
Mill, Brooklyn Mill, and Holt Mill. Of these, the Holt Mill was suspected to
be located in an alfalfa field downstream of the mouth of Butterfield Canyon.
Based upon the known historical information concerning the ore body and
other milling operations in the canyon, it is known that this mill processed
lead ores; however the location of wastes left over are unknown as is the
potential volume of said wastes. The suspected location of the mill was
sampled and no traces of milling or mining activities were found. Local
residents believe that filling operations in the 1950s buried this operation.
The Yosemite and Brooklyn Mills are located in the Yosemite drainage.
Lead ores were delivered to the mills via a tram from Yosemite #1 and #2
mines (and other sources); tailings from the mill were sluiced down the
drainage. The Yosemite and Brooklyn Mill footprints were not addressed
during the removal action (they are up-gradient of the Eastside Collection
System and buried by the Bingham Canyon Waste Rock Dumps in the upper
reaches of the Yosemite drainage). The Revere Mill located at the
confluence of Saints Rest and Butterfield Canyon was a stamp
mill/concentrator that from the late 1800’s to the early 1900’s processed lead
ores received via tram from mines in Yosemite and elsewhere. The Revere
Mill tailings were reported to have a 3.2% lead content. The Revere Mill
footprint was removed during the tailings removal project.

9
During the tailings removal action in the Yosemite and Saints Rest drainage
and confluence areas with Butterfield Canyon, sedimentation basins were
constructed in Butterfield Creek. These basins were installed to control
debris migration downstream during the removal work. For a period of 4
years (1997 to 2001) Kennecott monitored the water quality of Butterfield
Creek near the Canyon mouth for lead and arsenic concentrations (EPA
established a limit for lead of 500 mg/kg) in the Total Suspended Solids. In
1999 the sedimentation basins were removed per agreement between
Kennecott and the Utah Department of Natural Resources. In 2002
Kennecott reported on the monitoring activity in Butterfield Creek (see
Appendix C - Kennecott Utah Copper report entitled Final Report for
Compliance Monitoring of Suspended Solids in Butterfield Creek dated
January 18, 2002).

The side drainages (or gulches) to Butterfield Canyon (i.e., Queen, Olson,
Castro, Yosemite, Saints Rest, Black Jack and St. James) have waste rock
dumps located in their upper reaches. The Queen drainage (also known as
Black Jack) had tailings also left within its upper reaches. Though left in
place, these dumps (and tailings as it pertains to Queen’s Mine) are located
behind the Eastside Collection System. The Eastside Collection System
(Operable Unit No. 12 of the Kennecott South Zone) is an operating facility,
used to capture leach water running from the dumps both in the alluvium
down-gradient of the dumps and on the surface of the individual drainages.
To date, Kennecott has maintained compliance pursuant to the Groundwater
Protection permit over this system (see Appendix B - Communiqué with the
DWQ Groundwater Protection Program). Distinctly pointed out in the 2001
Record of Decision, waste rock and tailings were left in place at the Queen
Mine historic facility located in the Black Jack drainage. The volume of
waste rock left in place is unknown but it is known to have a maximum lead
and arsenic concentration of 31,500 mg/kg and 3150 mg/kg (respectively),
and a mean lead and arsenic concentration of 8916 mg/kg and 1646 mg/kg
(respectively).

c. OU3 Herriman Residential & Agricultural Lands: Located downstream of the
Butterfield Mine and Canyon sites is the farming community of Herriman
(comprised of the City of Herriman and areas within the jurisdiction of Salt Lake
County). Herriman residents and farmers have traditionally used the entire flow
of Butterfield Creek for irrigation of their crops and lawns. Wastes dumped into
the creek upstream were spread throughout the area by the Herriman irrigation
systems. Eighty-five properties were affected by the contamination within the
residential area. Another 238-335 acres of agricultural lands were also
contaminated by the irrigation waters.

i. Remedy for Herriman Residential & Agricultural Lands: During the
Herriman residential investigation and removal action (from 1996 to 2000)
surface and at depth soils (to a depth of 18 inches), impacted by mine
influenced irrigation water, were excavated and removed from some of the
85 residential properties in the developed portions of the City of Herriman
(incorporated as a town in 1999 and a city in 2001). These properties
represented approximately 46 acres. The removal action addressed soils
tainted with tailings; these soils had surface concentrations of lead (on
10
average) greater than 6000 mg/kg. These soils were removed by EPA, with
assistance from Kennecott.

Lead was found to be the primary contaminant of concern (COC) though
arsenic was also found to exist in high concentrations. Where lead was
elevated arsenic was elevated; hence the focus of the removal action was on
elevated lead concentrations. On average pre-removal surface lead
concentrations ranged from 0 to greater than 10,000 mg/kg. After removal,
the post removal (pre-capping) surface soils had lead concentrations (on
average) ranging from 0 to greater than 10,000 mg/kg.

It was noted from review of the removal action that at some of the residential
lots, the maximum excavation depth (18 inches) was achieved and the COCs
at that depth continued to be elevated. Backfilling these lots with the non-
engineered capping soil effectively created a barrier to prevent surface
contact to the elevated COCs. All non-engineered capping soils complied
with the removal action’s residential soil standard of 1200 mg/kg for lead
and 100 mg/kg for arsenic.

85 residential properties were investigated but not all 85 properties required
removal action. The table denotes the percentage of samples taken within the
removal area that were found to be within each of the noted lead
concentration ranges. The table further denotes the percentage of soils
removed that had a lead concentration within the specified ranges, from the
properties requiring cleanup (to a maximum depth of on average 18 inches).

Table 7– Lead concentrations in Herriman residential neighborhoods
(source, September 2001 Kennecott South Zone Record of Decision for
Operable Units 3, 6 & 7)
Range of lead
concentrations in soil
(Herriman residential)
Pre-removal
characterization
(surface)
Post-removal
(pre-capping)
Removed soils
0 – 400 mg/kg lead 16.8% 17.7% 4.9%
400 – 800 mg/kg lead 21.6% 22.9% 5.8%
800 – 1200 mg/kg lead 24.9% 21.7% 14.4%
1200 – 1600 mg/kg lead 15.4% 13.7% 28.3%
1600 – 4000 mg/kg lead 15.4% 20.5% 34.1%
4000 – 10,000 mg/kg lead 5.8% 2.9% 12.7%
>10,000 mg/kg lead 0% 0.6% 0%
(Percentages of total number of samples collected in the remediated area)

During the residential lands removal action, some properties had extensions
to the property that were classified as pasture lots or extended back yards.
On average these extensions of the investigated properties were not
addressed under the removal action because EPA did not assess that there
was a risk posed to human health or the environment, or the property owner
did not grant access.

Kennecott’s assistance was further provided in the form of disposal space for
excavated soils, at the Bluewater Repository (located behind the Eastside
11
Collection System) in the Bluewater I drainage near Bingham Canyon and
providing the replacement soil. Their participation was done under the
provisions of an Administrative Order on Consent, Docket No. (CERCLA-
VIII-97-08 dated July 9, 1997).

During the investigation of the residential properties, it became known that
the same water used to irrigate these properties in the past also was used (via
the Herriman Pipeline Company) to irrigate agricultural properties within the
community. As such, the UDEQ (with assistance from EPA, Kennecott, and
the community of Herriman) began to investigate the location of historic and
current irrigation ditches and canals to assess which agricultural properties
needed to be characterized. Approximately 238-335 acres of land (north,
east and west of settled parts of Herriman) used for agricultural activities
were investigated by UDEQ.

Similar to the residential properties, soils on the agricultural properties were
found to be impacted with elevated concentrations of lead and arsenic, but
lead was the primary contaminant of concern. Soils were tainted with
tailings and the average surface soil lead concentration was 12,595 mg/kg.

The following table approximates the percentage of properties (out of those
investigated by UDEQ) that had average lead concentrations (across the
whole of the property) within the specified concentration ranges. The table
further denotes the percentage of samples collected during the investigation
that fell within the specified lead concentration ranges. An approximate total
of 10,450 samples were collected during the agricultural land investigation.

Table 8– Lead in agricultural soils near Herriman (source, September
2001 Kennecott South Zone Record of Decision for Operable Units 3, 6 & 7)
Range of lead concentrations Property-wide
averages (%)
Individual samples
(%)
0 – 400 mg/kg lead 24.1% 31.5%
400 – 800 mg/kg lead 17.7% 15.2%
800 – 1200 mg/kg lead 14.5% 12.1%
1200 – 1600 mg/kg lead 11.2% 10.2%
1600 – 4000 mg/kg lead 27.4% 24.3%
4000 – 10,000 mg/kg lead 4.8% 6.4%
>10,000 mg/kg lead 0% 0.2%

The EPA selected a remedy which involved leaving the soils on the
agricultural properties in place, because they on average complied with the
applicable land use standards selected by EPA (Agricultural – 10,000 mg/kg
for lead and 300 mg/kg for arsenic) for the land use be implemented at the
time. To ensure redevelopment of these properties would address elevated
concentrations of lead and arsenic (when proposed) the EPA worked with the
City of Herriman (and tried to do so with Salt Lake County) to develop a
institutional controls (ICs) program (via the building permit process), where
the City of Herriman ensures that developers address the elevated lead and
arsenic based upon the proposed land use. No specific remedial steps to be
12
taken were specified, so as to make best use of management practices at the
time of proposed development.

2. OU6 Lark Waste Rock and Tailings: Includes areas in and near the former town of
Lark which were contaminated by wastes generated by historical mining activities.
Waste included waste rock from digging the tunnels and shafts of the mines, tailings
generated by several mills, and acid mine drainage discharged onto soils and into
holdings ponds. The area covered by tailings was approximately 470 acres; waste
rock was deposited on about 40 acres; and another 200 acres were affected by mine
drainage. It was estimated that there was about 5 million tons of tailings and 2
million tons of waste rock present on the site. The site is transected by two
intermittent streams, Midas Creek (entering from the northwest) traveling
approximately in a southeast direction along the north and easterly boundaries of the
tailings area and Copper Creek (entering from the west) traveling approximately east
along the southern boundary of the tailings area. Neither of which normally contains
water.

Within OU6 are the locations of several historic mining, and milling operations, and
waste deposits from these operations. These historical locations include: Proler (this
site is north of Bingham Creek and may be in a different OU), Dalton and Lark
Railroad, three Ohio Copper Company Mills, Fortune Mill, New Mammoth Mill,
Dalton and Lark Mill, Mascotte Tunnel, Mascotte Pond ( 1 acre), Mascotte Tailings
(i.e. Randolph Peterson Gate soils, 300 acres), Midas Creek, Midas Creek Silo area
( 3.5 acres), Southeast Area ( 45 acres), Lone Tree Tailings ( 2 acres), State
Motorcycle Park (actually on the Lark Tailings & Waste Rock site), Lark Waste
Rock, Randolph Peterson Gate soils (i.e. Mascotte Tailings), Copper Creek ( 10
acres) and Gulch, Copper Gulch Mines, East Side Bingham Canyon Dumps, Midas
Pond, Eastside Reservoir, Bingham Tunnel, and Old Bingham Tunnel.

Within OU6 there were two ditches that transected or traversed through the site (or
along sections of its periphery) that have led to discoloration of soils or distressed
vegetation in areas within the site. The Bastian Ditch operated from 1898 to
approximately 1936. The Mascotte Ditch operated from 1942 to 1971.

a. Remedy for OU6: Due to the size of OU6 UDEQ undertook a review of the
remedy in a piecemeal manner so that each facility comprising OU6 was
accounted for. It was understood from the September 2001 Record of Decision
covering OU6 that at the time of the ROD, all the removal actions adequately had
satisfied remedial objectives and EPA determined that no further action at Lark
was needed or required. Pursuant to this review (please refer to Chapter IX
Recommendations), this decision is not completely accurate.

Waste rock within OU6 that was documented as existing farther to the west
(associated with the noted historical mills, see Section A of this chapter) except
for Ohio Copper’s operations and the drilling of the Mascotte and Bingham
Tunnels, was found to be under the existing Bingham Canyon Waste Rock
dumps and behind the Eastside Collection System. No remedy was determined
to be necessary because these sites were buried. Ohio Copper’s operations were
the subject of the remedial or removal actions discussed below. The footprints of
the Ohio Copper milling operations (outside of the Mascotte Tunnel) were
addressed during the Lark Waste Rock and Tailings response work.
13

i. Lark Waste Rock: The Lark Waste Rock area was an area where the spoils
from drilling the Mascotte Tunnel (constructed in 1901) and Bingham
Tunnel (constructed from 1948 to 1952) were deposited. In addition to some
tailings left by the Ohio Copper Company mill No.1, there were twelve
dumps of waste rock in the Lark area. The waste rock dumps came from
driving the noted tunnels above, plus the Ohio Copper Company mine
workings (Long Dump), the U.S. and Lark Mine (Miscellaneous Dump), and
the Lark Mine waste rock (Round Dump). Around 1993 (under an EPA
Region VIII AOC, Docket No. CERCLA-VIII-98-09) Kennecott initiated
and completed a removal of waste rock from the site to the cleanup goals of
1000 mg/kg lead and 100 mg/kg arsenic. Approximately 2 million tons of
waste rock (that had an acid generating potential) was removed to the
Eastside Waste Rock Dumps of the Bingham Canyon Mine, located behind
the Eastside (leachate) Collection System. Pre-removal sampling
documented a maximum lead and arsenic concentration of 20,000 mg/kg and
296 mg/kg respectively. Said sampling also documented a mean lead and
arsenic concentration of 9631 mg/kg and 199 mg/kg respectively. As
delineated in the post removal reports, Table 9 below documents the average
lead and arsenic concentrations in post removal samples per pile.

Table 9 – Average lead and arsenic concentrations in post removal
samples collected from each Lark Waste Rock Pile (concentrations given
in mg/kg)
Pile No. Lead Arsenic
1 200 39
2 276 25
3 352 37
4 201 34
5 128 23
6 228 16
7 & 8 127 <50
9 302 <50
10 472 27
11 449 38
12 146 19
Average 261 32
* Data was derived from Kennecott drawing No. 451-T-3601 (March 1994)

No waste rock was left nor found (during the site inspection or records
search) to be left on site.

ii. Lark Tailings: The Lark Tailings area was an area where the Ohio Copper
Company milling wastes were deposited over the years (1909 to 1950’s).
Aerial photos (from the 1930’s onward) documented wind dispersion of the
deposited tailings in the predominant wind path in the Southwest corner of
the Salt Lake Valley. The milling and precipitation operations of Ohio
Copper Company (1909 to approximately 1950) left a large area (470 acres)
covered by tailings (7 to 8 million tons) with elevated lead and arsenic.
Characterization sampling determined a maximum lead and arsenic
14
concentrations of 9560 mg/kg and 790 mg/kg respectively. Said sampling
also determined a mean lead and arsenic concentration of 2153 mg/kg and
260 mg/kg. As noted in the September 2001 ROD, under an EPA Region
VIII AOC (Docket No. CERCLA-VIII-98-09) a removal action was
performed to address tailings with elevated lead and arsenic. However, a
review of the project records found multiple characterization efforts (two to
be exact) prior to and after a re-grading effort (not a removal) of the tailings
in Lark. Re-grading and reclamation of the Lark Tailings involved removing
areas where tailings deposition was thin, to expose native soils. Exposed
native soil was used as soil cover for areas containing thicker depositions of
tailings. A further topsoil cover was placed over the reclaimed tailings area;
soils were borrowed from local sources or other locations at Kennecott. Once
re-graded the tailings area was sampled (prior to application of the cover
soils) and the currently available documentation did not delineate sample
points above the potentially applicable UU/UE standards for lead and arsenic
(1200 mg/kg and 100 mg/kg respectively). But as noted from the previous
characterization effort, there were samples with lead and arsenic above the
potentially applicable UU/UE standards for lead and arsenic prior to re-
grading.

iii. Randolph Peterson Gate: The Randolph Peterson Gate area (a.k.a. Mascotte
Tails) is an area that is located approximately ½ mile northeast of Lark,
comprising approximately 200 to 300 acres characterized by stressed
vegetation and having red-stained soils. The area is on the west side of Hwy
111 near the Randolph Petersen Gate. Site history leads to a suspicion that
contaminated waters with arsenic in solution or suspended were collected in
this area because of its lower topography. Characterization data documents
arsenic concentrations in some samples as exceeding the potentially
applicable UU/UE standard for arsenic (100 mg/kg). The area did not
receive a formal removal action by Kennecott under the Lark response work,
but the soils were amended with calcium carbonate alluvium which was tilled
into the surface soils in 1993. Once amended, the site was covered with a 6
to 8 inch topsoil cover and then the whole area was reseeded. The soils
amendment action addressed the acidity characteristics of these soils.

iv. Bastian Ditch: The Bastian Ditch was used to transfer water primarily from
Bingham Canyon (Bingham Creek water amongst the sources) to the farmers
in Herriman to irrigate their fields. The Bastian Ditch transected OU6 in a
generally north to south direction entering east of Route 111 and north of
11800 South. The Bastian Ditch was potentially buried by the Lark Tailings,
but originally trended north to south through the tailings footprint and
continued in a southerly direction to Herriman. The Lark Tailings response
work did not address the Bastian Ditch directly, though indirectly the cover
over the top of the Bastian Ditch (in the area of the Lark Tailings) is likely
comprised of soils and regraded tailings. Subsequent to the time of the ROD,
both Kennecott Utah Copper and Kennecott Land removed or characterized
sections of the Bastian Ditch west of Rt. 111 and north of 11800 South. Both
response work activities are or will soon undergo an evaluation by the
Agencies, separate from this review. South of 11800 South the Bastian Ditch
is suspected of remaining in place.

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v. Mascotte Ditch: The Mascotte Ditch was used to transfer water from
Mascotte Tunnel (and potentially from Bingham Tunnel) to the Mascotte
Ponds, where the water was then supposedly used for irrigation purposes.
The Mascotte Ditch emanated from the portal of the Mascotte Tunnel (near
the Bingham Tunnel portal) and proceeded northeast along the northern
periphery of the Lark Tailings area. At the juncture of the Mascotte Ditch
and Bastian Ditch, the Mascotte Ditch continued in a generally easterly
direction past the Midas Creek Silos site and into the Mascotte Pond. The
Mascotte Ditch was not characterized or removed, nor was the area between
the Midas Creek Silos and Mascotte Pond (where red tainted soils were
observed at depth) suspected to be the corridor of the Mascotte Ditch. Midas
Creek was not characterized up or down gradient of the confluence of the
Mascotte and Bastian Ditches. How the Mascotte and Bastian Ditches
crossed Midas Creek is still unknown.

vi. Midas Creek Silos area: The Midas Creek Silos area was a location that had
3 concrete structures near the southeast corner of the intersection of Rt. 111
and 11800 South. After elevated lead concentrations near a culvert under Rt.
111 were discovered, further investigations were done. The Midas Creek
Silos area was found to have layers of tailings (similar to Lark Tailings) in
the channel of Midas Creek near an intersection with the Mascotte Ditch.
This area is suspected to be the location of the intersection of the Bastian and
Mascotte ditches. Characterization of the tailings determined a maximum
lead and arsenic concentration of 2643 mg/kg and 142 mg/kg respectively.
Said sampling also determined a mean lead and arsenic concentration of 454
mg/kg and 37 mg/kg respectively. Some of the sampled material was acidic,
with a paste pH of 3.56. Soils were often found to be discolored. The area
received a partial removal, after which it was regraded/recontoured. The
September 2001 ROD states that post removal sampling delineated a
maximum lead and arsenic concentration of 175 mg/kg and 37 mg/kg
respectively. Said post removal sampling also delineated a mean lead and
arsenic concentration of 160 mg/kg and 31 mg/kg. During this review,
representatives of Kennecott noted that not all of the Midas Creek Silos area
was characterized and it is possible that some soil containing elevated lead
and arsenic above the potentially applicable UU/UE standards may still
remain at the site.

vii. Mascotte Pond: The Mascotte Pond received water from the Mascotte
Tunnel via the Mascotte Ditch built in 1942. The water in the pond is
suspected to have been used for irrigation purposes on farmlands located
further south, from 1920 to 1935. Discharge from the Mascotte Pond was
suspected to have gone into Midas Creek. There is some suspicion that the
Bastian Ditch (which ran from the area of ARCO tails, OU5, to the south of
the Lark Tailings area near Copper Creek) may have contributed water to the
Mascotte Pond. Characterization of the site determined a maximum lead and
arsenic concentration of 12,300 mg/kg and 1100 mg/kg respectively. Under
the Lark removal work plan the sediments were removed from the pond and
placed into the Bluewater I Repository along with the Lark Tailings in 1993.
Post removal samples determined a maximum lead and arsenic concentration
of 620 mg/kg and 45 mg/kg respectively. Said sampling also determined a
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mean lead and arsenic concentration of 288 mg/kg and 20 mg/kg
respectively.

Between the Midas Creek Silos and the Mascotte Pond areas response
workers had observed discolored soils, but no characterization or subsequent
response work was initiated (Interview with Mr. Brian Vinton, NAMS, April
15, 2009). As noted by Mr. Brian Vinton there appeared to have been
corridor of red colored soils following a natural topographical flow path.

viii. Southeast Area: Located near the Southeast corner of the Lark Tailings
Area, was an open field that during the characterization and response work in
Lark was entitled, Southeast Area (approximately 45 acres). Stressed
vegetation was observed in this area and so it underwent a characterization.
This area was found to have been crossed by multiple ditches from early
farming activities. Characterization sampling delineated a maximum lead
and arsenic concentration of 17,000 mg/kg and 580 mg/kg respectively. Said
sampling delineated a mean lead and arsenic concentration of 2348 mg/kg
and 127 mg/kg respectively. Some of the soil paste pH samples were in the
range of 5.5. The Southeast Area underwent a removal action (under the
Lark removal work plan). Approximately 16,640 cubic yards of material was
removed to the Bluewater Repository (under the Lark response work). Post
removal sampling delineated a maximum lead and arsenic concentration of
232 mg/kg and 19 mg/kg respectively. Said sampling also delineated a mean
lead and arsenic concentration of 151 mg/kg and 11 mg/kg respectively.
After removal work, which is deemed protective of current land use (when
compared to potentially applicable open space and agricultural standards
found in the OU3 chapter of the Sept. 2001 ROD, please refer to Chapter IX
Recommendations) the Southeast Area was reclaimed and seeded.

ix. Lone Tree Area: Another location southeast of the Lark Tailings area was
found to exhibit stunted wheat growth, Lone Tree (approximately 2 acres).
The Lone Tree site is approximately 1 mile northwest of Herriman.
Characterization of the site delineated a maximum lead and arsenic
concentration of 646 mg/kg and 40 mg/kg respectively. Soil paste pH values
were delineated at a low of 4.67. During this review Kennecott noted that
this area received a minimal characterization and that it was reclaimed.

3. OU18 Acid Mine Drainage: OU18’s name is a misnomer. Though initially it was
thought that the various waste rock dumps associated with mine adits or tunnels
located along the western slope of the Oquirrh Mountains (Tooele County) might
have acid mine drainage issues, subsequent characterization did not discover any. A
number of facilities were investigated along the western slope of the Oquirrh
Mountains, as listed below.

a. Utah Metals Tunnel and Utah Metals Tunnel Dump: The Utah Metals Tunnel and
Utah Metals Tunnel Dump are sometimes referred to as Middle Canyon Tunnel
and Middle Canyon Dump or the Water Supply Tunnel and Water Supply Tunnel
Dump. This site is located in Middle Canyon, Tooele County, Utah. The tunnel
was driven in 1913 to facilitate a water exchange between Tooele and Bingham
City. The tunnel was also suspected to potentially have been used to transport
ores from the Carr Fork operations to the smelter on the Tooele side, and for
17
generation of water power. One end of the tunnel daylights in the Bingham Pit
and the other near Middle Canyon Creek. At the time of the North Zone & South
Zone ROD of September 2002, EPA noted that the historical water exchange
(between Kennecott and the irrigation company was no longer in force). The
tunnel is about 11,000 feet long and measures 8 feet by 9 feet. The associated
waste rock dump of the tunnel located on the Middle Canyon side is about 250
feet in diameter. The volume of waste rock is approximately 30,000 cubic yards.
The tunnel drainage is approximately 500 gallons per minute (gpm).

i. Remedy for Utah Metals Tunnel and Utah Metals Tunnel Dump: The Utah
Metals Tunnel is no longer used for ore haulage, transportation to and from
Tooele County to the pit, nor for water supply (under contract or enforced). In
2006 Kennecott (for safety purposes) constructed a concrete bunker around the
mine portal. This action forever sealed the portal from unauthorized access.
Water produced from along the length of the tunnel is collected and piped into
the holding and delivery system of a local irrigation company down-gradient
from the Utah Metals Tunnel Dump.

As noted above, there is an approximately 30,000 cubic yard waste rock dump
associated with the Utah Metals Tunnel in upper Middle Canyon (near where
the Tooele County paved road ends). Though occasionally visited by hikers
and bikers (there is a popular primitive campground nearby), most of the
potential exposures (if any) have an ecological receptor. A characterization of
the waste rock (in 2000) discovered (via grab samples) a maximum lead
concentration of 2110 mg/kg, a maximum arsenic concentration of 107 mg/kg,
and a maximum Selenium concentration of <0.5 mg/kg. Water quality samples
were also taken of the discharge from the tunnel. The results of the sample
analysis discovered an arsenic concentration of <0.005 milligrams per litter
(mg/L), a lead concentration of <0.005 mg/L, and a selenium concentration of
0.003 mg/L. Though the threat of an ecological impact (absent a formal risk
assessment) was deemed low, the continue erosion of the Dump’s
embankments and introduction of waste rock into the nearby Middle Canyon
Creek (used by wildlife for drinking purposes) was not desired by the EPA and
UDEQ risk managers.

As such, in 2000-2001 the Utah Metals Tunnel Dump underwent a reclamation
activity initiated by Kennecott and overseen by UDEQ. The Dump’s
embankments and top surface were regraded and a native seed mixture was
randomly scattered across the surface of the top of the dump. Revegetation
along the Dump’s embankments was reliant upon the voluntary introduction of
seed from establish stands of vegetation in the canyon and near the Dump. A
berm was constructed around the top of the Dump approximately 3 feet back
from the edge of the Dump’s embankments, and approximately 12 to 18 inches
high (the berm is also approximately 18 inches in width). The berm served the
purpose to direct surface water flowing from the tunnel toward a constructed
drainage channel located along the western embankment of the Dump. The
drainage channel directed run-off water from the top of the Dump down to a
wooden reservoir belonging to the local irrigation company. The berm also
served (and still does) the purpose to reduce the amount of run-off flow down
the Dump’s embankments to prevent continued erosion of these surfaces.
Material that had eroded from the embankments of the Dump and migrated
18
toward Middle Canyon Creek was drawn back toward the Dump embankments.
Middle Canyon Creek had a layer of rock placed in its channel to prevent
continued undercutting of the waste rock slope area.

Originally the Dump’s top surface drainage mechanism was an enclosed HDPE
pipe with a catch basin area on top of the Dump (see figure No. 73, Appendix
I) on the top of the western embankment. However, during a reconstruction of
the tunnel portal in 2006, water was pushed out from the tunnel and began to
undercut this drain/catch basin. Subsequent to this finding, Kennecott
reconstructed the Dump’s top surface drainage channel (in 2007) into an open
aired, significantly rip-rapped channel approximately 1.5 feet in depth, 1.5 feet
in width, and approximately 100 yards in length from the top of the Dump
down to local irrigation companies collection area. Also, Kennecott installed a
pipe inside the tunnel entrance which now serves to direct water produced by
the tunnel down off the Dump and into the local irrigation system (see Photos
No. 82-86, Appendix I). Since the water flowing from the tunnel portal
complies with applicable surface water standards for the beneficial use of the
Middle Canyon Creek and the irrigation system, no water treatment was
deemed necessary during any of the above listed remedial action.

Annual reports to UDEQ were required as part of this remedial/reclamation
activity. A map denoting the location of the Dump was also required as part of
the remedial action selected by EPA in 2002.

b. Other tunnels on the Western Slope or the crest of the Oquirrh Mountains: There
were numerous tunnels which were constructed to access Bingham Canyon
claims but with portals on the western slope of the Oquirrh Mountain range to
bring ores to the International Smelter in the 1920s to 1971 and later copper ores
to Anaconda’s concentrator located within Pine Canyon, Tooele County, Utah.
These other tunnels include: Apex (Parvenu) as connected to the Pine Canyon
Tunnel, Bingham West Dip, Adamson, Copper Boy, Spring Canyon Tunnels,
Upper Bruneau, and Helen B. At the time of the September 2002 North Zone &
South Zone ROD Kennecott owned the water rights associated with these
tunnels, but most of the water flows were and are still very small. The results of
the construction of these tunnels lead to a waste rock dump near one of the
completed portals. The International Smelter is separate NPL site.

Apex Parvenu Tunnel: Apex Tunnel was probably constructed between 1905 and
1907 and was used for haulage and drainage from the Apex working above the
1000 foot level. The Apex Tunnel interconnects with the Pine Canyon Tunnel
(Operable Unit No. 20 of Kennecott South Zone); both are at the same elevation.
The tunnel has also intersected with the Bingham Pit, and was proposed as a
possible method to transport tailings should a tailings disposal area be needed in
Tooele County; this plan was ultimately rejected.

Bingham West Dip Tunnel (Levine Tunnel): The Bingham West Dip Tunnel was
on the Angell claim and may have been built prior to 1900. There is no evidence
of any ore discoveries or extraction. By 1926, the tunnel had been converted to a
water supply tunnel and the water was piped to the International Smelter. The
tunnel was used for this purpose until 1985. The tunnel portal has subsequently
caved in, but a steel pipe transects the tunnel and discharges to a cement sump
19
near the portal and then to a storage tank outside the tunnel. There is a waste
rock dump near the tunnel portal. The volume of waste rock dump is
approximately 4150 cubic yards. The tunnel drainage is approximately 150 to
200 gpm. The tunnel is located in Pole Canyon, a tributary to Pine Canyon. The
water now spills out of the tank into the creek.

Adamson Tunnel: International Smelter drove this tunnel in 1925 to collect water
for its processing needs. Any excess not used by the smelter was sent down the
creek for use as irrigation water. The tunnel was 319 feet long and transected the
bottom of Pine Canyon. The water right associated with the tunnel is 413 gpm.
The tunnel drains into Pine Canyon via a water storage tank. Because of its
reported location is close to Pine Canyon Tunnel, it may have been obscured by a
mudflow. The tank overflows into Pine Canyon Creek.

Copper Boy Tunnel: Copper Boy Tunnel was located in Baltimore Gulch a
tributary to Pine Canyon. It is at 7700 feet elevation and has a water right of 200
gpm.

Spring Canyon Tunnels: Spring Canyon (located between Pine Canyon and
Middle Canyon), had three water tunnels (Hardrock Tunnel, McBride Tunnel and
Main Tunnel). The waters (water right totaling 325 gpm) were used by the
International Smelter for processing.

Upper Bruneau Tunnel: There is a Kennecott water right associated with a tunnel
located up Pass Canyon (just north of Pine Canyon) for 54.8 gpm. It is also
known as the Pass Canyon Tunnel.

Helen B Tunnel: There is a Kennecott water right associated with a tunnel
located on the south fork of Swenson’s Canyon (just north of Pine Canyon) for
20 gpm.

i. Remedy for Other Tunnels: From 1996 to 2000 the other tunnels (Apex
(Parvenu), Bingham West Dip, Adamson, Copper Boy, Spring Canyon
Tunnels, Upper Bruneau, and Helen B) and any waste rock dumps associated
with their construction were investigated to assess the need for remedial action.
Most of the tunnels were found to not have any waste rock dumps or issues
associated with them other than Bingham West Dip Tunnel. Sampling of the
Bingham West Dip Tunnel Dump found a maximum lead concentration of 236
mg/kg, a maximum arsenic concentration of 29.3 mg/kg and a maximum
selenium concentration of 36.3 mg/kg. These concentrations were found to be
within recreational soils standards (for lead and arsenic, protective of human
health) originally compiled for other operable units of the Kennecott North and
South zones, as well as being under the industrial land use standards
established for the Kennecott North Zone facilities. As such no remedial action
was selected for the Bingham West Dip Tunnel Dump.

The two tunnels that have significant water production (beyond the Utah
Metals Tunnel) include the Bingham West Dip Tunnel and the Upper Bruneau
Tunnel. Earlier samples from the Bingham West Dip Tunnel discharge
discovered an arsenic concentration of <0.005 mg/l, a lead concentration of
<0.005 mg/L, and a selenium concentration of 0.008 mg/L. A sample collected
20
in 2000 discovered an arsenic concentration of <0.005 mg/L, a lead
concentration of <0.005 and selenium was not reported on. Samples taken of
the water discharge from the Upper Bruneau Tunnel discovered an arsenic
concentration of <0.005 mg/L, a lead concentration of <0.005 mg/L and
selenium was not reported on. Most of the significant water discharges from
the tunnels in the area were studied during the investigation. The water was of
drinking water quality and therefore was assessed not to pose a threat to
potential downstream human users.

IV. Remedial Actions

Remedial action was pursued at OUs 3, 6, 7, 17, & 18, at various times. As noted above in
Chapter II & III, various decision instruments were used by EPA Region VIII for ordering or
selecting the necessary remedial actions; Administrative Orders on Consent or Records of
Decisions were used. For some of the “facilities” of each of the operable units, characterization
through a non-traditional preliminary assessment/site investigation process determined that no
further action was necessary. In other cases removal or remedial action was required. Please
refer to Chapter III above.

The past response work had the general objectives to:
· Prevent ground water contamination from uncontrolled releases of acids and
metals leached from waste rock piles
· Prevent exposures of humans to unacceptably high levels of lead and arsenic in
soils, based on different exposure rates at different land uses
· Prevent downstream migration of unacceptable levels of lead and arsenic in
waters used for irrigation by homeowners and farmers
· Protect flora and fauna in areas which are prime wildlife habitat

For OU18 the response work had the following general objectives:
· Reduce or eliminate unacceptable levels of exposure to wildlife
· Reduce or eliminate unacceptable levels of exposures to recreational and
industrial works

Specific remedial activities for these operable units are listed in Chapter III, under Section B
above. For OU7 & 17 please refer to Appendix J. For some of the operable units operation and
maintenance requirements were selected as part of the remedial response actions.

A. OU3 Butterfield Mine, Canyon & Creek, Herriman Residential & Agricultural Lands

The City of Herriman agreed to supervise long term management of the agricultural
properties of Herriman using the authorities invested in its building permits and land use
planning divisions. The UDEQ (with funding from EPA) has offered in the past, and
continues to do so, assistance to the City of Herriman during proposed redevelopments to
assessed management strategies for addressing the elevated lead and arsenic concentrations.

The Salt Lake County was initially approached by EPA back in 2000 to receive an
education concerning the results of the sampling efforts by UDEQ and EPA. The goal of
the outreach was to have Salt Lake County develop an ICs program similar to what the City
of Herriman developed. The EPA began to pursue negotiations with the County to assist
them with developing an ICs program for those portions of the site within the jurisdiction
21
of Salt Lake County. To date, no such program has been found to exist and in the future as
properties within the site begin to develop such actions will likely drive the need for such a
program at Salt Lake County.

B. OU6 Lark Waste Rock & Tailings, Ancillary Facilities

Pursuant to the September 2001 Record of Decision EPA Region VIII had assessed that the
removal and remedial work that had been implemented under the Lark removal work plan
was sufficient to address risks at the site posed to the then receptors. EPA Region VIII
stated that no further action or institutional controls were necessary for the site.

During this review UDEQ coordinated with Kennecott to assess the project documentation
to assess if there is the potential for waste left in place within OU6. Said review has
determined that there is the potential, if not the actual existence of lead and arsenic above
the potentially applicable UU/UE standards.

C. OU18 Acid Mine Drainage

Long term management of the remediation/reclamation of the Utah Metals Tunnel Dump
and the surface water controls structures fell to Kennecott as the land owner. Again as
noted previously, there is not a perceived human health threat from either the waste rock
contaminants of concern (i.e. lead) or from the tunnel discharge water. There is the
potential for downstream ecological receptors to become impacted from drinking the water
if the waste rock were to continue to be eroded into Middle Canyon Creek. Pursuant to the
long term management plan, Kennecott is required to inspect the Utah Metals Tunnel and
Utah Metals Tunnel Dump on an annual basis and report to UDEQ – DERR on the
observations.

The UDEQ – DERR project manager periodically joins Kennecott during the annual
inspections.

V. Progress Since Last Five Year Review

This was the first five year review for these operable units of the Kennecott South Zone site.

VI. Five Year Review Process

A. Administrative Components

Pursuant to the UDEQ and EPA Site Specific Enforcement Agreement (dated April 2007)
UDEQ took the lead to perform this first five-year review of the referenced operable units.
Work was initiated by the UDEQ-DERR project manager (Mr. Douglas Bacon), on June
2008 and initial involved staff of UDEQ-DERR and EPA Region VIII as part of the
Kennecott five year review team.

At times representatives from the local government entities and the responsible party were
contacted and used as a resource to assess ongoing developments and to inspect pertinent
records. The resource group included the following:

22
Michelle Baguley, Herriman City Council Member, long-term advisor to the Kennecott
South Zone Technical Review Committee and Technical Advisory Group Coordinator for
the Herriman Residential and Agricultural Removal and Assessment projects;

Larry Elkin, North American Mine Services, a Kennecott contractor now and at the time of
the original cleanups.

Gordan Haight, City of Herriman Engineer, individual responsible to ensure that the City of
Herriman implements the institutional controls program required by the September 2001
Record of Decision:

Jorry Howell, City of Herriman Engineering Department, department inspector working
with the City Engineer to ensure implementation of the institutional controls program.

Kelly Payne, Principle Advisor for Closure and Remediation for Kennecott Utah Copper,
the Kennecott Superfund response action manager;

Brian Vinton, North American Mine Services, a Kennecott contractor now and at the time
of the original cleanups.

During June 2008 the review team established the review schedule (which subsequently
was adjusted mid-way through the review) and delineated the components of the review,
which included:

· Community Involvement;
· Document Review;
· Data Review;
· Site Inspections;
· Local Interviews; and
· Five Year Review Report Development and Review

Because of the added review elements (per the request by EPA Region VIII Enforcement)
the scheduled for completion was initially extended to December 2009. However, per
request by EPA HQ’s staff, this review was slated for completion by September 30, 2009.

The review was conducted by first listing the changes which could have occurred at the site
since the original removals were conducted and then evaluating if changes took place and if
so, did these changes result in possible impairment of the remedies. Changes included
changes of land use, changes due to weathering, and changes due to construction activities.
To determine if the remedies remained effective in protecting human health and the
environment, each operable unit was visited and appropriate records inspected.

Where it was suspected that hazardous substances might have been uncovered or still
remained on-site above potentially applicable UU/UE standards, such areas were
investigated. Kennecott and City of Herriman participants aided in the location of these
areas. Where appropriate, existing monitoring data was gathered from existing resources to
assess potential disturbances as part of developing the recommendations included herein.

23
B. Community Involvement

In-person community interviews for the OU3 and OU18 five-year reviews were
conducted in the Salt Lake Valley and Tooele Valley. The interviews were conducted by
Mr. Dave Allison and Mr. Douglas Bacon of UDEQ-DERR. Residential property owners,
municipal officials and representatives of the RP were interviewed. The results of the
community interviews are given in Appendix A.

An announcement that EPA was conducting a five-year review appeared in both daily
newspapers (Salt Lake Tribune and Deseret News) on August 28, 2008 (see Appendix
A).

C. Document Review

This five year review consisted of a review of relevant documents including:

· State of Utah Groundwater Protection and UPDES permit records
· Reports on subsequent cleanups performed under existing O&M plans
· Past cleanup report documentation to assess the existence of soils left in place
exceeding potentially applicable UU/UE standards

The documents reviewed are listed in Appendix H; excerpts of such are also reproduced in
Appendix B, C, D, F, & G. The two Records of Decision, dated September 28, 2001 and
September 26, 2002 were also evaluated for cleanup requirements and pertinent ARARs.
On an operable unit specific basis the following records were evaluated during this review.

1. OU3 Butterfield Mine, Canyon & Creek, Herriman Residential & Agricultural Lands:

a. State Permits: Kennecott has kept monitoring records with regard to sump waters
and ground water at the Bluewater repositories which hold the wastes from the
Herriman residential cleanup project, as well as some of the removal projects in the
Butterfield Canyon area. The records are included in the annual Ground Water
Permit report provided to the DWQ. A review of the permit records found
compliance with the permit limitations at the monitoring wells associated with the
Bluewater Repository (Appendix B - Communiqué with DWQ Groundwater
Protection Program, permit compliance).

Though periphery to Butterfield Canyon, the active drainages up-gradient (i.e.
Queen, Olson, Castro, Yosemite, and Saints Rest) have cutoff walls installed to
prevent alluvial and surface flow and to assist in the control of surface water
drainage from the waste rock dumps in these drainages. The cutoff walls are a
series of concrete dams, keyed into bedrock down-gradient of the waste rock
dumps, used to ensure the containment of acid mine drainage from the dumps.
Though the Eastside Collection System is Operable Unit 12 of the Kennecott South
Zone, oversight of this facility was deferred to the DWQ under its Groundwater
Protection Program permit. As part of the five-year review process for Butterfield
Canyon, DERR inspected the compliance record of Kennecott with the permit
limitations of the DWQ Groundwater Protection Program. To date, Kennecott has
been in compliance with the permit limitations (Appendix B - Communiqué with
DWQ Groundwater Protection Program, permit compliance).

24
Since cleanup of the Butterfield Mine and Canyon/Creek sites, Kennecott has
maintained compliance with the UPDES permit associated with the Butterfield
Mine Tunnel discharge. An inquiry and review of the DWQ database documented
compliance with the permit limitations for outfall #10. Monitoring records from
the DWQ found that Butterfield Creek was not impaired for water quality
(Appendix B - Communiqué with DWQ UPDES Program, permit compliance).

b. Post Removal Sampling: A review of the removal action documentation and post
removal samples for the Butterfield Canyon Waste Rock and Tailings removal
areas determined (Appendix F),

i. 1 grab sample (prior to backfilling) in the area of the Butterfield Mine Waste
Rock removal action was found to exceed the potentially applicable
unrestricted land use/unrestricted exposure standard for arsenic (100 mg/kg).
This sample was found to be located in a steep section of the Canyon along
the southern topography of the removal area. The post removal sample had
an arsenic concentration of 150 mg/kg, exceeding the potentially applicable
unlimited land use/unrestricted exposure (UU/UE) standard for arsenic (100
mg/kg arsenic).

ii. 4 grab samples (prior to backfilling) in the drainage confluence area of Saints
Rest and Butterfield Canyon (also the location of the Revere Mill footprint
along the north side of the Salt Lake County Road) exceed potentially
applicable UU/UE standards for lead and arsenic (1200 mg/kg lead, 100
mg/kg arsenic). Because the County road was not removed and two of the
post removal samples were taken from soils near the road, it is suspected that
under the road in this section of Butterfield Canyon soils do exist above the
potentially applicable UU/UE standards for lead and arsenic.

iii. 2 grab samples (prior to backfilling) in the drainage confluence area of
Yosemite and Butterfield Canyon exceed the potentially applicable UU/UE
standards (1200 ppm mg/kg lead, 100 mg/kg arsenic). Because the County
road was not removed and one of the post removal samples was taken from
soils near the road, it is suspected that under the road in this section of
Butterfield Canyon soils do exist above the potentially applicable UU/UE
standards for lead and arsenic.

iv. 6 sample locations were found to exceed the potentially applicable UU/UE
standards for lead and arsenic (1200 mg/kg lead, 100 mg/kg arsenic) in the
Queen’s mine site and drainage. Though not remediated during response
work, it was noted that this area is in the upper reaches of the Queen’s
Drainage (a.k.a. Black Jack drainage), on mine owned and managed
property, and is fairly steep. Land use supported by the area is industrial and
open space.

c. City of Herriman Institutional Controls Program: A review of the City of
Herriman’s building records found the following projects underwent a remediation
effort during a redevelopment project, since the EPA selected remedy has been in
place. Activities at these sites suggest a need to further evaluate the surface and
near surface soils (refer to Chapter IX Recommendations).

25
Table 10– Remediation projects during redevelopment in the City of
Herriman
Property
HAG No.
Development
Name
Contaminant
Management Plan
Plan Date Completion
Date
Multiple
properties
Butterfield
Creek Storm
Drain
No information
available
No
information
available
No
information
available
010 Western
Creek
All arsenic/lead
contaminated soils
excavated (approx. 8600
yds3) from the
residential portion of the
development remains
entirely on-site in the
soil repository on the
open space portion of
the development. Soil
repository was covered
with a minimum of 2
feet of clean fill
(undefined).
8/1/2006 7/2/2007
011 Black Hawk
Estates
Soils containing lead
from 1600-4000 ppm &
arsenic 100-850 ppm
were placed in a non-
residential open space
with 2 feet of cover
(undefined). Soils
greater than lead of
4000 ppm & arsenic of
850 ppm were
transported to
Kennecott’s Bluewater
Soil Repository.
9/28/2007 11/7/2008
010, 011,
012, 019,
020
Butterfield
Creek Sewer
Project –
South Valley
Sewer
District
@ HAG 10, 11, 12, 19,
20 soils above the
residential levels were
used as backfill in the
sewer pipeline. Lead &
arsenic above 1600 ppm
& 100 ppm on Ms.
Myrna Carter’s property
was treated as
commercial and topsoil
was left on the surface
at her request.
8/16/2007 12/22/2008
020 Silver Bowl
Estates Lots
#112 & #113
ONLY
Samples showed that
lead & arsenic levels
were low enough that
remediation was not
3/1/2006 12/5/2005
26
required for Lots #112
& #113 in Silver Bowl
Estates, as determined
by the City of Herriman.
021 Lafayette
Estates
Subdivision
Contaminated soil is
planned to be removed
and deposited off-site,
on an easterly adjacent
property. The
contaminated soil will
be covered with 18
inches of soil (undefined
for COCs).
12/1/2006
025 Sunset
Meadows
Subdivision
Soils are to be removed
and located in the future
commercial area of the
subdivision.
8/1/2004
030 * Tuscany
Estates
Site owner and
developer applied to the
VCP to manage the
redevelopment and
disposal of soils with
elevated lead and
arsenic. Residential lots
were remediated to 1200
ppm for lead and 100
ppm for arsenic. Phase
5, soils repository, was
never finalized in terms
of run-on/run-off
management, cap
preservation and
institutional controls
and the State
subsequently withdrew
the project from the
VCP.

030 Garbett
Homes –
Herriman
Downs
Soils containing 1600
ppm lead or greater
were removed to the
Kennecott Repository.
4/1/2006 10/1/2006
031 Herriman
Parkway
Top of soils returned to
trench.
No
information
available
No
information
available
033 Umbria
Estates
All lead & arsenic soils
that was excavated from
the residential part of
the development was
contained in a repository
under the commercially
12/1/2005 5/1/2006
27
developed section of the
property.
*Information on the Tuscany Estates Project was derived from the UDEQ’s
project file under the Voluntary Cleanup Program. Dates are provided for when
the property entered the VCP and when it was withdrawn. It was noted by the
reviewer that the City of Herriman is intending to develop a portion of Phase 5,
along the southern boundary of the contaminated soils pile, as a primary
thorough-fare into the City.

2. OU6 Lark Waste Rock & Tailings:

a. Response Action Reports: During this five-year review Kennecott representatives
assisted with a review of the response work documentation to assess what was
historically done to address OU6. This information assisted UDEQ to understand
where waste (soils with elevated concentrations of lead and arsenic above the
potentially applicable UU/UE standards for lead and arsenic) could still exist on
site. As noted above, portions of Lark Tailings and the ancillary sites of Midas
Creek, Midas Creek Silos, Mascotte Ditch, Bastian Ditch (south of 11800 South),
Randolph Peterson Gate, Southeast Area, and potentially Copper Creek have soils
with lead and arsenic above the potentially applicable UU/UE standards. Maps
and data tables documenting the characterization and post response soil analyses
are provided in Appendix G of this report.

b. State Permits: Lark Waste Rock was removed and relocated onto the Eastside
Waste Rock Dumps of the Bingham Canyon Mine. These dumps are located
behind the Eastside Collection System which is operated by Kennecott in
compliance with a Utah Groundwater Protection Permit (Appendix B -
Communiqué with DWQ Groundwater Protection Program, permit compliance).
The Eastside Collection System prevents meteoric water from filtering out of the
dumps and into the valley alluvium aquifer. Some “hotspots” from the Lark
Tailings area where hauled to Bluewater I Repository. This repository is operated
and maintained by Kennecott in compliance with a Utah Groundwater Protection
Permit (Appendix B). All removal materials from OU6 are prevented from
migrating, by being disposed of in approved disposal areas behind or in capture and
containment facilities.

c. Post Construction Sampling: Beyond the initial characterization and post response
work sampling that was performed in the early 1990’s, no further sampling has
been done at OU6. Since the initial response work, there has been limited reuse of
the OU6, its ancillary sites, and adjacent lands.

Offset from the northern, eastern and southern boundaries of the Lark Tailings
reclamation area adjacent lands have continued to be dry farmed as they have
historically. No sampling data was available.

Between 2001 and 2002 Kennecott Land constructed a soil haul road to take soils
being removed from the footprints of the South Jordan Evaporation Ponds and
Bastian Sink areas in the Daybreak Community to the Copper Notch repository
located on the Eastside Waste Rock Dumps in Copper Gulch. The haul road
transected through the Southeast Area and into the Lark Tailings reclamation area
along its southern boundary. No soil samples were taken prior to construction of
28
the road corridor. Approval of the road construction was granted by EPA Region
VIII during the approval of the South Jordan Evaporation Ponds and Bastian Sink
removal work plans submitted by Kennecott Land between 2001 and 2002.

3. OU18 Acid Mine Drainage:

Though required to submit annual inspection reports to UDEQ on the management of
the Utah Metals Tunnel and Utah Metals Tunnel Dump site, a review of the project
record found submission to be sporadic by Kennecott. However, it should be noted that
the risk potentially posed by this site (if left uncontrolled) was previously deemed
minimal by the risk managers. UDEQ has gone on inspections of this site periodically
with Kennecott, and has seen Kennecott take an active role to address the potential for
uncontrolled releases from the site when they have arisen.

The other tunnels (and associated waste rock dumps or water discharges), i.e. Apex
(Parvenu), Bingham West Dip, Adamson, Copper Boy, Spring Canyon Tunnels, Upper
Bruneau, and Helen B, are primarily located in tributaries of Pine Canyon. Though
Pine Canyon (separate operable unit under the Kennecott South Zone, OU20) does not
require a five-year review (as noted in the UDEQ documented entitled Five-Year
Review Schedule & Operable Unit Inclusion dated February 14, 2008), a review of
Kennecott’s compliance with the water quality limitations associated with outfall 009
was performed. Pursuant to a communiqué from the DWQ (see Appendix B -
Communiqué from DWQ concerning UPDES permit compliance for outfall 009)
Kennecott has maintained compliance since 2001 with the UPDES discharge
limitations for Pine Canyon.

During the community interviews with representatives of Tooele County (i.e.
Engineering and Planning Departments and County Council) no proposed
developments were brought to UDEQ’s attention for the areas of the other tunnels and
dumps of OU18. The County Engineering Department representative made an inquiry
about what type of land use the Utah Metals Tunnel Dump site might support (without
specifically relating a imminent desire or plan for redevelopment activity). It was
noted during the interview that the Utah Metals Tunnel Dump and Tunnel are owned
by Kennecott and until land ownership were to change this site remains un-developable
by third parties.

a. Post Construction Sampling: Beyond the sampling performed during
characterization activities at the Utah Metals Tunnel, Utah Metals Tunnel Dump,
and other Tunnels and associated dumps (i.e. Apex (Parvenu), Bingham West Dip,
Adamson, Copper Boy, Spring Canyon Tunnels, Upper Bruneau, and Helen B) no
other sampling has been performed as of the time of this review.

D. Data Review

Sampling, as a part of the scope of work for this five-year review, was not performed.
However, existing data (where pertinent) was evaluated (in some cases re-evaluated) to
understand the nature and extent of material with COCs above potential UU/UE standards.
The following is an operable unit by operable unit listing of what data was reviewed.

29
1. OU3 Butterfield Mine, Canyon & Creek:

Available data (from post removal sampling) was re-evaluated to ascertain if soils (with
COCs above potential UU/UE standards) were left in place. As noted from the maps
and data tables provided in Appendix F, soils above potentially applicable UU/UE
standards for lead and arsenic still remain within the response work areas, for Saints
Rests and Yosemite drainages. Similarly, soils above potentially applicable UU/UE
standards for lead and arsenic were left in place in the upper reaches of Queen drainage
near the Queen Mine workings.

As part of evaluating the remedy, data made available from the DWQ concerning the
quality of water within Butterfield Creek was reviewed. As noted in Appendix B,
water quality in Butterfield Creek (in terms of Total Suspended Solids, T-Pb and T-As
have remained low) since cleanup activities were pursued.

2. OU3 Herriman Residential & Agricultural Lands:

Beyond the original characterization and (in some cases) the post removal sampling,
there has been limited sampling since the ROD was approved in Sept. 2001. Though
some redevelopment projects were pursued since remedy implementation, soil data
from these projects was not available at the time of this review.

The lack of available post remedial response work data is a concern. If in the future
post removal sampling data is not available, the recommendation herein (Chapter __
Recommendations) includes a sampling event to screen existing soils for potential
COCs above the applicable land use standards listed in the 2001 ROD.

3. OU6 Lark Waste Rock & Tailings:

Available data (from post removal sampling) was re-evaluated to ascertain if soils (with
COCs above potential UU/UE standards) were left in place. As noted from the maps
and data tables provided in Appendix G, soils above potentially applicable UU/UE
standards for lead and arsenic still remain within the response work areas, for Lark
Tailings and the ancillary facilities at the operable unit.

No specific data was reviewed for OU7, 17, & 18 as part of this review. As noted in
Appendix J, the UDEQ and EPA Region VIII previously evaluated post removal data
collected by Kennecott Land after their response work under the December 2006 O&M
plan implemented at OU7 & OU17. As such, the UDEQ project manager did not re-
evaluate this same data as part of this review. The remedy at OU18 did not require ongoing
monitoring and as such there was no quantitative data to evaluate. If in the future,
stabilization of the Utah Metals Tunnel embankments becomes problematic future reviews
could re-evaluate the need for monitoring the conditions of suspended solids loading to
Middle Canyon Creek through monitoring activities.

E. Site Inspection

Various site inspections took place at the operable units covered under this review, at
different times. The primary inspector was the UDEQ project manager, who was assisted
or joined at various times by UDEQ’s community outreach specialist, and representatives
of Kennecott. Please direct your attention to Appendix I for the individual sites inspections
30
photo & observation logs. The following are narratives on what was observed at the
operable units when inspected.

1. OU3 Herriman Residential & Agricultural Lands, Butterfield Mine, Canyon & Creek:
Inspections at the site were performed most recently on September 25, 2008 by the
UDEQ project manager (see Appendix I). The purpose of the inspection was to
evaluate the Butterfield Mine, Butterfield Canyon/Creek and Herriman Residential &
Agricultural Properties cleanup areas to determine if there were possible damages to
the remedies by: (1) changes in the land use, (2) changes in the topography of the site
due to construction, (3) changes in the topography due to erosion, and/or (4) changes in
conditions which are different than those assumed during the design of the remedies.
The existence (or lack thereof) of institutional controls (ICs) and their effectiveness
was assessed by discussing the existence of such with City and County representatives
(see Appendix A and Chapter IX Recommendations).

Since implementation of the remedy in Herriman, property use has remained relatively
the same. The agricultural properties are primarily used to raise either alfalfa or other
crops (dependent upon the planting cycle). Some of the agricultural fields have been
left to fallow and subsequently have been repopulated with native weed species such as
grasses and forbs (i.e. sage and rabbit brush). The residential properties also appeared
to be structural intact (in terms of consistent vegetated soil covers). (See Appendix I,
Photos No. 1 thru 6).

The City of Herriman has noted that only a few large development projects (on the
lands with elevated lead and arsenic) have been pursued to date. The most notable (and
the ones inspected by UDEQ) include: (1) Tuscany Estates (partially completed,
withdrawn from the State of Utah Voluntary Cleanup Program), (2) Western Creek, (3)
Blackhawk.

a. Though Tuscany Estates (i.e. Fassio Egg Farm) was remediated and homes have
been constructed, under the State of Utah VCP program the management status of
Phase 5 (soil repository) along its northern property boundary has not been
completely addressed. The VCP applicant has been withdrawn and the property
associated with the soil repository has been given to the City of Herriman. Current
development plans by the City call for the construction of a road, during which
soils unearthed will be managed by the City of Herriman’s contractor pursuant to
the City’s ICs program.

b. The Western Creek and Blackhawk developments (in close proximity to each
other) have undergone a remediation (interview with Mayor Crane, February 25,
2009). Soils with elevated concentrations were primarily hauled off to the
Kennecott repository (under a negotiated agreement). It is currently suspected that
some soils have been consolidated and capped onsite, (interview with Mr. Brian
Vinton, North American Mine Services, NAMS, September 25, 2008 and site
inspection). These two developments have not proceeded beyond the initial
grubbing and remediation exercises.

c. Around 2003/2004 the Salt Lake County Flood Control division initiated and
completed the construction of a storm water sewer (buried pipe) between
approximately 6200 West and 5600 West, parallel to and within the historic
drainage of Butterfield Creek. Though it is widely thought by individuals familiar
31
with the project that the excavated soils in the agricultural lands this pipe crosses
were placed back into the excavation and capped in place, no documentation at this
time has been retrieved to document such steps. (See Appendix I Photos No. 6).

Absent overseeing the Salt Lake County Flood Control Division’s efforts to construct
the noted storm water sewer, the City of Herriman has been involved with the above
listed development projects (see Chapter VI. Section C). The ICs program for the
Herriman agricultural lands requires a property owner or developer to apply for a
building permit, and address the remediation of waste (i.e. soils with lead and arsenic
exceeding the listed land use standards in the 2001 Record of Decision for OU3, 6, &
7). As noted above, soils appeared to have been managed from a remedial perspective
(based upon the planned change in land use), but as noted in there is not post
remediation sampling data.

With no exceptions, the revegetation efforts during the removal and reclamation
activities in Butterfield Canyon and Mine were in excellent shape. As noted in the
pictures (see Appendix I, Photos 7 thru 18) it is hard to imagine that a removal action
was undertaken in the Canyon. Since the implementation of removal activities, there
has been but a few incidences or issues related to the waste rock dumps in the upper
reaches of the side drainages (i.e. Queen, Olson, Castro, Yosemite, Saints Rest, Black
Jack and St. James).

A previous inspection of Butterfield Canyon was done in 2007 by UDEQ in response to
a storm event and release that took place in the Yosemite drainage (Appendix D -
DERR Inspection Report dated August 28, 2007). Beyond the response action
(inspection to ensure protection of the CERCLA remedy) by UDEQ – DERR project
manager, the State of Utah Division of Oil, Gas and Mining (DOGM) and the UDEQ
Division of Water Quality (DWQ) were involved and pursued separate action per their
authorities. The material released (i.e. tailings) was observed along the bottom of the
drainage and in the Butterfield Creek channel. Samples taken delineated lead and
arsenic concentrations in compliance with the agricultural and open space standards set
in the 2001 Record of Decision for OU3. As noted in Appendix I (Photos No. 9&10)
and during discussion with the Stormwater Protection Permit manager for DWQ (see
Appendix B) Kennecott has addressed upgrades to the storm water run-off system to
maintain compliance with DWQ’s permit.

2. OU6 Lark Waste Rock & Tailings:

On April 23, 2009 UDEQ – DERR project manager coordinated with representatives of
Kennecott (Mr. Kelly Payne and Mr. Brian Vinton) and conducted a site tour of OU6.
The purpose of the inspection was to assess current conditions of the various facilities
associated with OU6, and to assess if soils with lead and arsenic were left on site above
UU/UE concentrations. Existing vegetative covers were observed, as were site control
features (though it was noted no security requirements were selected as part of the
earlier response work). Records were inspected by Kennecott personnel to assess the
existence of soils in place with elevated COCs (lead and arsenic) above the potentially
applicable UU/UE standards.

The areas associated with or addressed as part of the response work performed at OU6
were found to be in relatively good and stable condition. The current surface grades
were found in tact, with just a few minor occurrences of tailings (within the area of
32
Lark Tailings) at the surface. The majority of the post response surfaces were well
vegetated, though the increasing population of jack rabbits in the area is starting to
overgraze the existing vegetation.

The following remarks are provided for the primary facilities inspected.

a. Mascotte Tunnel and Bingham Tunnel: The Mascotte Tunnel (driven in 1902) and
the Bingham Tunnel (driven in 1948-52), both were found to have water discharges
associated with them. The water produced from along the length of the tunnels is
currently captured by Kennecott and placed into their water collection and
management system, which is operated in compliance with a Utah Groundwater
Protection Permit. (See Appendix I, Photos No. 19 thru 31).

b. Lark Waste Rock: The area of the waste rock removal project was found to be in
good condition, successfully vegetated and supportive of current land uses (i.e.
open space, agricultural, industrial). The two inspected dump sites (i.e. Long
Dump and North Dump) epitomize the current land characteristics of the other 8
dump removal sites. In one of the dump removal location (i.e. Long Dump) an
experimental wetlands treatment project addressing seep water with elevated
sulfate concentrations was found to no longer be actively managed as a wetlands
treatment project, but was sustaining some wetland wildlife (i.e. red-winged
blackbirds, mallards, deer). (See Appendix I, Photos No. 31 thru 40).

c. Lark Tailings: The Lark Tailings Response area is the largest area at OU6 and is
bounded by the ancillary facilities discussed previously (i.e. Midas Creek Silos,
Mascotte Ditch, Midas Creek, Bastian Ditch, Mascotte Pond, Southeast Area, Lone
Tree area, and Copper Creek). The Lark Tailings area that underwent regarding
and reclamation was found to be fenced off from the surrounding farm lands that
are being used to grow hay and/or alfalfa. In one location, near the Southeast Area,
the fence was found to be in disrepair and/or actually removed to facilitate haul
trucks removing soils from the Daybreak area (OU7) under EPA Region VIII
approved plans. (See Appendix I, Photos No. 41 thru 66).

No ICs were assessed to be in use for this site.

3. OU18 Acid Mine Drainage:

UDEQ-DERR project manager performed an inspection in August of 2005 and June
2008 of the Utah Metals Tunnel and Utah Metals Tunnel Dump to determine if there
were possible damages to the stabilization work by: (1) Changes in the land use, (2)
Changes in the topography of the site due to construction, (3) Changes in the
topography due to erosion, and/or (4) Changes in conditions which are different than
those assumed during the design of the remedies. During both inspections the UDEQ-
DERR project manager was joined by representatives of Kennecott (Mr. Kelly Payne
and Mr. Brian Vinton).

Over the two inspections the UDEQ-DERR project manager observed the continuously
successful establishment of a vegetative cover, via voluntary seeding. The remedial
response work implemented by Kennecott was two fold, (1) regrade the Dump surfaces
(and where possible the embankments) to better control run-off water (derived from
precipitation and tunnel flow), and (2) stabilize the Dump embankments and the
33
channel embankment of Middle Canyon Creek. Revegetation by the voluntary seeding
from nearby grasses, wildflowers, and alpine trees was selected by Kennecott to allow
for native species of plants to populate the Dump. Kennecott’s efforts to reduce the
impact from recreational vehicles were observed to have increased the success rate of
this voluntary seeding.

The Utah Metals Tunnel Dump was assessed to support open space land use, and the
Dump’s embankments were observed to be fairly stable. The southern embankment
(due to its slope ratio) continues to show rilling problems, but the material did not
appear to be migrating into Middle Canyon Creek. As noted in Chapter IV.C, the
institutional control selected for this site (i.e. mapping where COCs exist above
potentially applicable UU/UE standards) has yet to be completed.

F. Interviews

For OU3 & 18 please refer to Appendix A for the summary report on community
interviews and individual interview logs, for the interviews performed by UDEQ.

Though initially not included in the scope of five-year review, OU6 was assessed as
requiring a five-year review due to documentation of potential wastes left in place (refer to
section C of this chapter). During the review it was assessed that the public has limited
access to the site and the nearest town (City of Herriman) is approximately 5 to 6 miles to
the south by southeast. Since no public live on, near or within site boundaries, UDEQ did
not interview any public directly accessing OU6.

The only periodic use of land adjacent to the OU6 is by a farmer dry cropping the land
bordering the north, east and south boundaries of the Lark Tailings reclamation area.
Limited Kennecott employee and contractor support access exists to ensure management
and upkeep of the Bingham Tunnel, Mascotte Tunnel, and water management facilities
(plus other ancillary buildings used in support of the mine operations). The only long term
worker presence onsite is at the Lark Gate (access point to the Bingham Canyon Mine)
located approximately ¼ mile from the Mascotte Tunnel, Bingham Tunnel, USSRM
buildings and the site of the Lark Waste Rock – North Dump site.

Since the site is within the jurisdiction of Salt Lake County and was assessed to need
institutional controls to manage future changes to land use, UDEQ staff spoke briefly to
County staff and was unable to conduct formal interviews for this review. Salt Lake County
welcomed future discussions regarding information on institutional controls for this area.

VII. Technical Assessment

A. OU3 Butterfield Mine, Canyon & Creek, Herriman Residential & Agricultural Lands

1. Question A: Is the remedy functioning as intended by the decision documents?

a. Butterfield Mine, Canyon & Creek: The removal actions on average were
successful to remove elevated concentrations of lead and arsenic, from the site of
the Butterfield Mine, Canyon & Creek. A review of post removal reports found
that current surface grades comply with open space and recreational land use
standards selected under the 2001 ROD. Though un-noticed during the site
inspection, Butterfield Canyon (and to a lesser extent Creek, for purposes of
34
foraging and in limited cases nesting) represents prime wildlife habitat. However
there are no endangered species or threatened species within this habitat.
Continued monitoring of Butterfield Creek (under Utah’s UPDES program) has
found compliance with applicable water quality standards. A site inspection of this
portion of OU3 found the current surface grade stable and well vegetated, with
little disturbance of sub-grade soils both within the Canyon and Creek. No
ongoing operation and maintenance, access control, or monitoring requirements
exist. No ARARS or institutional controls were selected under the 2001 ROD.

In two locations (the confluences of Saints Rest and Yosemite drainages with
Butterfield Canyon) post removal samples document (at depth) soils with elevated
lead and arsenic above potentially applicable UU/UE standards (on average 2 to 3
feet below the current surface grade). As long as current surface grades (comprised
of either soil covers, or road base/asphalt) remain intact these portions of OU3 are
protective of current land uses (i.e. recreational and open space), with unlimited
access. This review did not assess an ecological risk, as long as surface covers
remain intact.

The findings of the document review suggest that institutional controls should now
be considered (see recommendations Chapter IX). If land use were to change from
recreational and/or open space, and the soils with COCs above potentially
applicable UU/UE standards were to be excavated, some kind of control to ensure
compliance with the RAOs should be developed.

b. Herriman Residential & Agricultural Lands: The review of documents, discussions
with the staff of the City of Herriman and the site inspection found the remedy as
selected by EPA Region VIII under the 2001 ROD, on average functioning as
intended. Based upon current land use, the past response work, and the selection of
ICs for these portions of OU3, the implemented remedy has currently achieved the
RAOs. No ongoing operation and maintenance, access control, ARARs or
monitoring requirements exist.

Past removal response work addressed 85 residential properties, through
characterization and in some cases removal of soils with elevated COCs above the
residential cleanup goals to a depth of 18 inches. During the inspection a select
number of these properties were looked at and found to have surfaces with various
types of vegetative cover, in various stages of success. To the understanding of the
City of Herriman staff, none of these residential properties have been proposed for
subdivision and redevelopment. The knowledge of where elevated COCs in soils
are located on these properties was found to be limited after reviewing available
documentation and discussions with the City of Herriman staff. No operation &
maintenance, or monitoring requirements were selected as part of the long term
remedy. These properties (when proposed for subdivision) are considered by the
City of Herriman to be subject to the ICs selected for the agricultural properties.

The agricultural lands (primarily used for raising crops, but in some cases as
pasture lots) were largely found in use for the same land use as noted during
remedy selection. Some of these properties have been left to fallow, and hence
could be considered as open space. The ICs selected for these properties are
intended (and are functioning) to ensure that during redevelopment (dependent
upon the proposed land use) soils with elevated COCs are managed appropriately.
35
The City of Herriman has been implementing the ICs program for properties in
their jurisdiction; a few redevelopment projects were observed.
The ICs program implemented by the City of Herriman is a self certification
program, in that no independent verification of compliance with applicable land use
standards is done by the City of Herriman. During the review inquires to arrange
interviews with representatives of Salt Lake County (who has jurisdiction over
some of the agricultural, and in a few cases the residential properties) were
unsuccessful. During these inquires it became known that the County does not
have an ICs program in place to ensure proper management of soils with elevated
COCs during redevelopment. As such, this review has provided a number of
recommendations for the remedy at this portion of OU3, please refer to Chapter IX.

As of the time of the site inspection, the procedures for developing properties in
Herriman with elevated COCs were undergoing revision. An opportunity was
present for the UDEQ-DERR project manager to assist the City of Herriman with a
review of the proposed development procedures on lands with elevated COCs.
Some concerns arose during this review and as noted in the recommendations for
this portion of OU3, Chapter IX, an opportunity is available to help the City of
Herriman enhance the ICs program.

The ICs program developed for the City of Herriman is meant to ensure that during
the review of a development proposal, if the property in question resides in the
sensitive lands overlay zone the developer is responsible to ensure that COCs are in
compliance with the intended land use. The developer is responsible to provide a
plan documenting how elevated COCs above the land use standards will be
addressed, implement the plan and document final soils conditions once the
remedial work is done. A limitation of the ICs program is that it was not intended
to ensure management of potential soil migration during farming practices. This
will potentially become more problematic as the current lands used for agricultural
activities begin to be developed.

2. Question B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial
action objectives (RAOs) used at the time of the remedy selection still valid?

a. Butterfield Mine, Canyon & Creek: The remedial action objectives (listed in the
2001 ROD for the residential and agricultural lands of Herriman) could be
considered applicable for this portion of OU3. Based on the findings noted from
the document review and site inspection, these RAOs are currently being
complied with,

· Prevent ground water contamination from uncontrolled releases of
acids and metals leached from waste rock piles
· Prevent exposures of Humans to unacceptably high levels of lead and
arsenic in soils, based on different exposure rates at different land uses
· Prevent downstream migration of unacceptable levels of lead and
arsenic in waters used for irrigation by homeowners and farmers
· Protect flora and fauna in areas which are prime wildlife habitat

i. Changes in Standards and To Be Considers: Since the completion of removal
work was done prior to the 2001 ROD, EPA Region VIII stated that no further
36
work was required for these portions of OU3. As such, no ICs or ARARs were
developed. However as noted above in VII.A.1.a, there are some locations
where soils exist above potentially applicable UU/UE standards at depth. The
2001 ROD did not select UU/UE standards for the soils located in OU3. So the
UDEQ-DERR project manager made use of the residential cleanup standards
(1200 mg/kg lead and 100 mg/kg arsenic) used during the residential cleanup
around the City of Herriman, for purposes of comparing the soils located at
depth in Butterfield Canyon to potential land use options. As noted in the
recommendations chapter (Chapter IX) the Agencies should consider the
development of UU/UE standards for OU3.

The requirements of the following federal rules or acts are potential ARARs
that should be considered during soil cleanup activities in the Butterfield
Canyon area (in light of potential change to current land use practices, and
because of the elevated COCs above potentially applicable UU/UE standards).

· Occupational Safety and Health Act (OSHA),
· Superfund Amendments and Reauthorization Act (SARA) (as it
pertains to notification of spills to the environment),
· Clean Air Act (CAA), and
· Clean Water Act (CWA)

The following protection programs or rules of the State (and their federal
equivalents) of Utah, should be evaluated as potential state ARARs in light of
potential change to current land use practices, and because of the elevated
COCs above potentially applicable UU/UE standards.

· Surface water protection programs (UPDES and Stormwater) and
groundwater protection programs,
· Air quality protection regulations (most notably the Fugitive Dust Rule
and National Emission Standards for Hazardous Air Pollutants,
NESHAP),
· Hazardous waste (generation, transportation and disposal) regulations,
· Solid waste regulations (most notably R 301 through R303, and R315-
8), and
· Utah OSHA regulations

ii. Changes in Exposure Pathways: The exposure pathways for this site were
presented in the Preliminary Remediation Goals for Addressing Risk to Human
Health From Exposures to Chemicals in Kennecott Soils (Dec 1999) in which
the Kennecott site was divided into two zones. Exposure pathways considered
for the Kennecott South Zone, which is where Butterfield Mine, Canyon, and
Creek are found, include Recreational Visitors, Commercial Workers, and
Industrial Workers. The Recreational Visitor exposure pathway includes
ingestion of surface soils and inhalation of airborne particulates through
activities such as all-terrain vehicle use, horseback riding, camping, hiking,
hunting and picnicking. The commercial and Industrial Worker exposure
pathway includes ingestion of surface soils and interior dust and inhalation of
airborne particulates. Current land use remains the same as present in the 2001
ROD. No changes to the exposure pathways are expected as long the future
37
land use is consistent with current land use. However, if in the confluence area
of Butterfield canyons with Saints Rests and Yosemite canyons, if the current
land use changes and excavations were to intrude approximately three feet
beneath current surface COCs will be present. Thus the above mentioned
exposure scenarios potentially will no longer be protective.

In reference to the review of the 2001 ROD it is noted that the development of
the recreational standard for lead and arsenic made use of a document entitled
Butterfield Canyon Ecological Risk Assessment (1997). This document was
not found during this phase of document review, thus an evaluation of the
ecological exposure assumptions were not completed at this time. Based upon
the data review of the removal project, the understanding that existing COCs
are at depth and the surface grades in these areas are stable it is not suspected
that there would be a current exposure risk to ecological receptors. Future
reviews should consider the destabilization of these known buried COCs, to
evaluate potential future exposure risks.

iii. Changes in Toxicity, and Other Contaminant Characteristics: There have been
no changes in the toxicity factors or characteristics for the COCs that were used
in the Preliminary Remediation Goals for Addressing Risk to Human Health
From Exposures to Chemicals in Kennecott Soils (Dec 1999).

iv. Changes in Risk Assessment Methods: There has been no change to the
standardized methodology that could affect the protectiveness of the response
action.

v. Expected Progress Towards Meeting RAOs: Because no further action was
selected as the remedy for Butterfield Mine, Canyon & Creek (after the initial
response action), no RAOs were selected (as noted above). However,
comparable RAOs for the community of Herriman were deemed applicable for
this portion of OU3 during this review. As long as the COCs at depth in the
Canyon remain at depth, compliance with the applicable RAOs will be met.

b. Herriman Residential & Agricultural Lands: The remedial action objectives
(listed in the 2001 ROD for the residential and agricultural lands of Herriman)
are for the most part being complied with. The RAOs are:

· Prevent ground water contamination from uncontrolled releases of
acids and metals leached from waste rock piles
· Prevent exposures of Humans to unacceptably high levels of lead and
arsenic in soils, based on different exposure rates at different land uses
· Prevent downstream migration of unacceptable levels of lead and
arsenic in waters used for irrigation by homeowners and farmers
· Protect flora and fauna in areas which are prime wildlife habitat

In cases of land use changes, compliance with the RAOs (as measured by
analytical testing) was not able to be verified as part of this review. Analytical
results from soil sampling were not available for data review.

38
i. Changes in Standards and To Be Considers: Past removal action addressed
cleanups at various residential properties, to attain a goal of 1200 mg/kg lead
and 100 mg/kg arsenic. In some cases, soils above these concentrations were
left 18 inches or deeper (because 18 inches was the established max depth for
cleanup). Coinciding with these soils at depth on the residential properties,
soils above the various land use standards selected in the 2001 ROD were left
on the surface and at depth on the agricultural properties. ICs were selected for
implementation and management by the local jurisdictions over building
permits (City of Herriman and Salt Lake County) and said programs were to
make use of the land use standards listed in the 2001 ROD as benchmarks to
ascertain the need for cleanup work, when redevelopment is proposed. Though
the standards are generally still okay to ensure protectiveness for public health
and the environment, the Agencies could consider the adoption of UU/UE
standards for this and other portions of OU3.

Since no further removal action was required under the 2001 ROD (unless
redevelopment proposals are submitted), EPA Region VIII did not list any
federal or state ARARs under the ROD for continued remedial work. A
notation was made about the potential need to address sensitive habitat
regulations if a developer were to build in such areas (i.e. wetlands). No
ARARs addressing the generation, treatment or disposal of contaminated soils
were ever selected. The noted ARARs that could be considered for the
Butterfield Canyon and Creek portion of the site (VII.A.2.a) could be
considered for the Herriman portion as well.

ii. Changes in Exposure Pathways: The exposure pathways were defined for the
community of Harriman in the Endangerment Assessment for Herriman, Utah,
Residential Soil-Lead Removal and the Preliminary Remediation Goals for
Addressing Risk to Human Health From Exposures to Chemicals in Kennecott
Soils (Dec 1999). These exposure pathways included Residential (including
Day care and Playgrounds), Recreational/Open space, Commercial, Industrial
and Agricultural. The Residential exposure pathway includes ingestion of
surface soils and interior dust. The Recreational Visitor/Open Space exposure
pathway includes ingestion of surface soils and inhalation of airborne
particulates through activities such as all-terrain vehicle use, horseback riding,
camping, hiking, hunting and picnicking. The commercial and Industrial
Worker exposure pathway includes ingestion of surface soils and interior dust
and inhalation of airborne particulates. The agricultural exposure pathway
includes the ingestion of surface soils and inhalation of airborne particulates.
Currently the community’s growth has significantly expanded since the 2001
ROD. Both residential and commercial development has happened at this site.
While many of these developments have replaced uncontaminated agricultural
lands, there are instances that some homes have been built on areas of known
contamination that may or may not have been cleaned up prior to construction.
Additionally, some homes that were cleaned up previously as part of the
residential removal action may have COCs below the 18 inch horizon and large
properties may have had an extended back yard that wasn’t cleaned up.
Therefore, there is a greater chance that a person living in a residence may have
a greater risk of exposure from living on theses properties. Local
Government’s (Herriman City and Salt Lake County) have the responsibility to
39
implement the selected ICs of the remedy, which equivalent to a self
certification cleanup program.

iii. Changes in Toxicity, and Other Contaminant Characteristics: There have been
no changes in the toxicity factors or characteristics for the COCs that were used
in the Preliminary Remediation Goals for Addressing Risk to Human Health
From Exposures to Chemicals in Kennecott Soils (Dec 1999) and the
Endangerment Assessment for Herriman, Utah, Residential Soil-Lead
Removal.

iv. Changes in Risk Assessment Methods: There has been no change to the
standardized methodology that could affect the protectiveness of the response
action.

v. Expected Progress Towards Meeting RAOs: As residential and agricultural
properties begin to undergo land use changes, assurance of compliance with the
selected RAOs is a function of the ICs programs (of which there is not one at
Salt Lake County). It is recommended that current and future compliance with
the selected RAOs should be evaluated as a follow up action pursuant to this
review.

3. Question C: Has any other information come to light that could call into question the
protectiveness of the remedy?

Periodically in the spring, Utah experiences rain events that at times are localized and
fairly strong. Prior to upgrades to the Eastside Collection System, storm events in the
upper reaches of the side drainages to Butterfield Canyon (most notably the Yosemite
Drainage) historically caused waste rock to migrate into Butterfield Creek and down
into the community of Herriman (most notably in 1997 and most recently in 2007). In
2008 (as reported in the Salt Lake Tribune) storm events during the month of May
caused for flooding in the area of 6000 West from 11800 South to 12600 South. There
was a potential for soils with elevated COCs on agricultural lands in this area to
migrate. The ICs remedy and lack of ARARs does not account for this type of event.

4. Technical Assessment Summary

According to the data reviewed, the site inspections and the interviews the remedy for
OU3 Herriman and Agricultural lands is functioning as intended by the 2001 ROD.
However, there are currently opportunities to enhance the ICs remedy and potentially
increase the scope of what it is intended to cover or manage. The City of Herriman’s
procedures for development has some noted deficiencies (Chapter IX
Recommendations) that could be addressed. Though infrequent, significant storm
events can cause for localized migration of soils with elevated COCs. No ARARs for
soil contamination were considered at the time of the 2001 ROD, and should be
considered now. There have been no changes in the toxicity factors for the
contaminants of concern that were used in the risk assessments and there have been no
changes to the standardized risk assessment methodology that could affect the
protectiveness of the remedy.

According to the data review, the site inspections, document review and interviews
with Kennecott representatives the response work performed at Butterfield Mine,
40
Canyon & Creek was successful to address a cleanup to current land use goals (open
space, recreational). However, there are soils a depth in the Canyon above potentially
applicable UU/UE standards for lead and arsenic. An opportunity is available to
develop appropriate ICs, ARARs and UU/UE standards to assist with addressing soil
contamination in the future at the time of land use changes. There have been no
changes in the toxicity factors for the contaminants of concern that were used in the
risk assessments and there have been no changes to the standardized risk assessment
methodology that could affect the protectiveness of the remedy.

B. OU6 Lark Waste Rock & Tailings

1. Question A: Is the remedy functioning as intended by the decision documents?

The removal actions on average were successful to remove elevated concentrations of
lead and arsenic, from the site of OU6, Lark Waste Rock & Tailings. A review of post
removal reports found that current surface grades comply with open space and
recreational land use standards selected under the 2001 ROD for a nearby operable
unit, OU3. A site inspection of OU6 found the current surface grade stable and well
vegetated, with little disturbance of sub-grade soils. No ongoing operation and
maintenance, access control, or monitoring requirements exist. No ARARS or
institutional controls were selected under the 2001 ROD.

Pre and post remedial action samples (Appendix G) document portions of Lark Tailings
and the ancillary sites of Midas Creek, Midas Creek Silos, Mascotte Ditch, Bastian
Ditch (south of 11800 South), Randolph Peterson Gate, Southeast Area, and potentially
Copper Creek as having soils with lead and arsenic above their potentially applicable
UU/UE standards. UDEQ-DERR project manager assessed that because of OU6’s
location to the community and similarity to the wastes that caused the lead and arsenic
impacts in the community of Herriman, the residential standards for lead and arsenic
(listed in the 2001 ROD) were a good benchmark to start with for this comparison. As
long as current surface grades (comprised of either soil covers, or road base/asphalt)
remain intact these portions of OU6 are protective of current land uses (i.e. recreational
and open space), with unlimited access. For this comparison, the benchmarks provided
in the 2001 ROD for OU3 for open space and recreational land uses were used (for the
same reasons that the residential standards were used).

2. Question B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial
action objectives (RAOs) used at the time of the remedy selection still valid?

The findings of the document review suggest that institutional controls should now be
considered (see recommendations Chapter IX), to protect public health in the future at
the time land use is changed. If land use were to change from recreational and/or open
space at OU6 to residential, and the soils with COCs above potentially applicable
UU/UE standards were to be excavated, some kind of control to ensure compliance
with the applicable RAOs is necessitated.

The remedial action objectives (listed in the 2001 ROD) for the removal action could
be considered pertinent for the ongoing remedial concerns (when land use is changed).
These removal action RAOs include:

41
· Prevent ground water contamination from uncontrolled releases of acids and
metals leached from waste rock piles
· Prevent exposures of Humans to unacceptably high levels of lead and arsenic
in soils, based on different exposure rates at different land uses
· Prevent downstream migration of unacceptable levels of lead and arsenic in
waters used for irrigation by homeowners and farmers
· Protect flora and fauna in areas which are prime wildlife habitat

a. Changes in Standards and To Be Considers: Since the completion of removal
work was done prior to the 2001 ROD, EPA Region VIII stated that no further
work was required for all of OU6. As such, no ICs were developed nor were any
ARARs listed for consideration. However as noted above in VII.B.1, there are
some locations where soils exist above potentially applicable UU/UE standards at
depth. The 2001 ROD did not select UU/UE standards for the soils located in
OU6 (nor any other land use standards or benchmarks). So the UDEQ-DERR
project manager made use of the residential cleanup standards (1200 mg/kg lead
and 100 mg/kg arsenic) used during the residential cleanup around the City of
Herriman, for purposes of comparing the soils remaining potentially at the
surface and at depth, in OU6. As noted in the recommendations chapter (Chapter
IX) the Agencies should consider the development of UU/UE standards for OU6.

The requirements of the following federal rules or acts are potential ARARs that
should be considered during soil cleanup activities in the Lark Tailings area (in
light of potential change to current land use practices, and because of the elevated
COCs above potentially applicable UU/UE standards). Such consideration
would take place at the time of redevelopment.

· Occupational Safety and Health Act (OSHA),
· Superfund Amendments and Reauthorization Act (SARA) (as it
pertains to notification of spills to the environment),
· Clean Air Act (CAA), and
· Clean Water Act (CWA)

The following protection programs or rules of the State (and their federal
equivalents) of Utah, should be evaluated as potential state ARARs in light of
potential changes to current land use practices, and because of the elevated COCs
above potentially applicable UU/UE standards. Such consideration would take
place at the time of redevelopment.

· Surface water protection programs (UPDES and Stormwater) and
groundwater protection programs,
· Air quality protection regulations (most notably the Fugitive Dust
Rule and National Emission Standards for Hazardous Air Pollutants,
NESHAP),
· Hazardous waste (generation, transportation and disposal)
regulations,
· Solid waste regulations (most notably R 301 through R303, and
R315-8), and
· Utah OSHA regulations
42
b. Changes in Exposure Pathways: It is understood from the document review that
a removal action was performed under an AOC at OU6. As such no formal risk
assessment was conducted, although it is suspected that the most likely exposure
pathways are recreational/Open Space, Industrial and Agricultural (from the
Preliminary Remediation Goals for Addressing Risk to Human Health From
Exposures to Chemicals in Kennecott Soils (Dec 1999). The Recreational
Visitor/Open Space exposure pathway includes ingestion of surface soils and
inhalation of airborne particulates through activities such as all-terrain vehicle
use, horseback riding, camping, hiking, hunting and picnicking. The commercial
and Industrial Worker exposure pathway includes ingestion of surface soils and
interior dust and inhalation of airborne particulates. The agricultural exposure
pathway includes the ingestion of surface soils and inhalation of airborne
particulates. When future land use is proposed appropriate exposure pathways
should be considered.

In terms of ecological receptors, no formal ecological risk assessment was
performed. However, in the 2001 ROD elk, deer, cougars and birds were listed
as potential ecological receptors to impacted groundwater and soils. As noted
during the inspection performed at OU6 as part of this review, deer (e.g. mule
deer) red wing blackbirds and mallard ducks were observed near the groundwater
seep. At least one coyote and two jack rabbits were observed in the Lark
Tailings area. At the time of this review, it was impossible to evaluate a risk of
exposure or pathway for these species.

c. Changes in Toxicity, and Other Contaminant Characteristics: Based upon a
review of the 2001 ROD, soils with elevated lead and arsenic were addressed
(either through removal action or regrading). Some soils with an acid generation
capacity received a lime treatment and were revegetated (i.e. Randolph Peterson
Gate soils) and for a limited time groundwater appearing at a localized seep (i.e.
Experimental Wetlands) underwent an experimental wetland sulfide bioreactor
treatment. It is known that no formal risk assessment was performed at OU6
prior to this response work, so a formal evaluation of the toxicity and chemical
characteristics of these potential COCs was not done.

d. Changes in Risk Assessment Methods: No formal Risk Assessment could be
found.

e. Expected Progress Towards Meeting RAOs: The removal action and larger scale
re-grading efforts at the Lark Tailings portion of OU6 provided a surface soil that
is consistently complying with the RAOs. However, when the land use in OU6
undergoes a change, it is possible that compliance with the RAOs may need to be
addressed again.

3. Question C: Has any other information come to light that could call into question the
protectiveness of the remedy?

The Lark Tailings area and the Experimental Wetlands (constructed during the early
response work) are being used by wildlife (Appendix I). The site inspection of OU6
observed deer, coyote, jack rabbit, red-winged blackbirds and mallards making use of
the habitat located within OU6. Some of the observed species are transitory, in that
they are not utilizing the area of Lark Tailings or its ancillary facilities (i.e.
43
Experimental Wetlands) as a permanent home. These species (deer, coyotes) are
potentially traveling through as they forage. The jack rabbit (non-native species in
Utah) population has begun to grow and at least represents one species likely utilizing
the Lark Tailings and ancillary facilities as their primary habitat. At least one burrow
was observed along the eastern edge of the Lark Tailings site (Photo No. 60, Appendix
I) and tailings material was observed on the current surface. Document reviews did not
find concerns related to ecological impacts during the response work development, and
no formal ecological risk assessment was found for OU6. There is currently no
agriculture use within ¼ mile of the Lark Tailings. The habitat presented at Lark
Tailings (and some of its ancillary facilities) represents good wildlife habitat, absent
significant human influence.

It is understood from interviews with representatives of Kennecott, that OU6 represents
a significant land holding which is primed for redevelopment. Population growth
continues to encroach on the open spaces available along the western portions of Salt
Lake Valley. Future prospects for OU6 are likely to see a mixed use development
project within the next century.

4. Technical Assessment Summary

According to the data review, the site inspections, document review and interviews
with Kennecott representatives the response work performed at Lark Waste Rock &
Tailings (and the ancillary facilities) was successful to address a cleanup to the then
selected land use goals (open space, recreational). However, there are potentially soils
at the surface and at depth at the Lark Tailings and ancillary facilities above potentially
applicable UU/UE standards for lead and arsenic. An opportunity is available to
develop appropriate ICs, ARARs and UU/UE standards to assist with addressing soil
contamination in the future at the time of land use changes.

Because of the transitory nature of the species making use (for foraging and nesting) of
the Lark Tailings and ancillary facilities (more specifically the Experimental
Wetlands), and because the one residential species (jack rabbit) is not an endangered
species (and is a non-native species in Utah), this review did not assess a need for an
ecological assessment specific to this site. In the past there was a broader ecological
assessment done for the Oquirrh range (both the crest of and certain canyons along the
range). The results of which are recommended as being applicable for OU6.

No formal risk assessment was done for the response work performed at OU6; as such
no evaluation of the toxicity of the COCs was initially done. Since no formal risk
assessment was performed, a review of risk assessment methodology was not
completed under this five year review.

C. OU18 Acid Mine Drainage

1. Question A: Is the remedy functioning as intended by the decision documents?

OU18 (though consisting of more than one site, comprising mostly of tunnel, adits and
waste rock piles) had one remedial response action that was required for one of the
facilities within it. The Utah Metals Tunnel Dump was known to have at least one
sample documenting an elevated lead concentration. As noted in previous text, the area
of the Utah Metals Tunnel and Utah Metals Tunnel Dump (located in the mid-upper
44
reaches of Middle Canyon, Tooele County) is primarily used for open space and
recreational land use. The mine currently retains ownership and access to the top
surface of the Dump is limited to pedestrian traffic. The elevated lead datum was of
concern to the Agencies because at the time of remedy selection (primarily reclamation
action) the Dump embankments were unstable and material was being washed into
Middle Canyon Creek, a source of water for localized wildlife. The reclamation efforts
by Kennecott to manage tunnel discharge and precipitation run-on/run-off was found to
continue to be effective to minimize the migration of dump material (i.e. waste rock)
into Middle Canyon Creek.

The Utah Metals Tunnel waste rock dump in Middle Canyon is largely comprised of
limestone and limey quartzite. On the geologic map of the Bingham District as
presented in Bingham District Guidebook, Plate 1, 1991, the Utah Metals Tunnel cuts
through Butterfield Peaks and Bingham Mine formations. More than 8000 ft of the
11,500 ft long tunnel from the Middle Canyon Utah Metal Tunnel Portal to the
Bingham Pit encountered the limestone and limey quartzite units. Utah Metals Tunnel
drains out both portals with approximately 8,000 ft of the tunnel draining to Middle
Canyon and about 3,500 ft that drains to Bingham Pit. Water quality of the water that
drains to Middle Canyon has a neutral pH and all inorganic parameters meet drinking
water quality.

Waste rock in the Utah Metals Tunnel Dump, as observed, contains a large percentage
of limestone and very limited amounts of intrusive rock. The intrusive rock weathers to
clayey type soil with moderate amounts of iron.

Kennecott has sampled the waste rock as part of the Priority Site investigations and
found that the average lead concentration was 2110 ppm and other metals and
metalloids were less than typical residential standards for the southwest Salt Lake
Valley mining impacted areas. Kennecott also leach tested the sample containing 2110
ppm lead with SPLP and all RCRA eight analytes were less than detection. Kennecott
also sampled the only yellow colored area on the Dump that measures approximately
60 ft by 60 ft on the top surface for agronomic purposes. This area contained intrusive
volcanic rock altered to clay and it had a pH of 5.92 and conductivity of 2400
umhos/cm. Because this altered volcanic rock is surrounded by limestone and limey
quartzite waste rock, it is not viewed as problematic in terms of producing acid and it
does support vegetation.

The data collected from the Utah Metals Tunnel Dump area suggests that ARD is not a
current problem and would not be a future problem. Drainage from the Utah Metals
Tunnel drains an area of low sulfide content and high limestone and limey quartzite.
The tunnel portal water has been used by Middle Canyon Irrigation Company for
almost 100 years and based upon the drainage capture area of the tunnel, it is
anticipated that water quality will not change appreciably over the future.

Though the Dump’s southern embankment continues to show signs of riles or gullies
caused by precipitation run-off (Photos No. 70-71 & 80-81, Appendix I) it should be
noted that this erosional action is caused by precipitation hitting the embankment’s
surface (not flowing off the top of the Dump). Though this erosion is causing for waste
rock to migrate, there is a toe berm at the base of the dump which has been successful
to prevent the eroded material from washing into Middle Canyon Creek. The eastern
and western slopes of the Dump are not as steep as the southern and were not observed
45
to have as significant erosional activity. The reclamation efforts to prevent overflow
from the Dump’s top surface has been very successful to reduce this erosional action,
as shown by the increase in successive plant growth along the southern embankment
from year to year.

2. Question B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial
action objectives (RAOs) used at the time of the remedy selection still valid?

The Agencies selected (in the 2002 ROD) the following RAOs for OU18,

· Reduce or eliminate unacceptable levels of exposure to wildlife
· Reduce or eliminate unacceptable levels of exposures to recreational and
industrial workers.

The reclamation efforts pursued from 2006 to 2007 by Kennecott were assessed to be
sufficient to attain these RAOs, which continue to remain valid.

a. Changes in Standards and To Be Considers: Since the completion of the
reclamation efforts on the Dump surface and the construction of the run-on/run-off
controls (completed in phases from 2006 to 2007), the Agencies have agreed that
only continued site inspections to assess the condition of these controls is
necessary. No ICs were developed nor were any ARARs listed for consideration,
because they were not necessary at the time of accepting the reclamation response
work. Neither is currently necessary as of this review, because current land
ownership and use is intended to remain the same for some time.

b. Changes in Exposure Pathways: There was no formal risk assessment developed
for OU18. The remedial decisions (i.e., stabilization of the Utah Metals Dump)
was not based on a human health risk assessment, but relied on information
provided in the Preliminary Remediation Goals for Addressing Risk to Human
Health From Exposures to Chemicals in Kennecott Soils (Dec 1999) and an
Ecological Risk Assessment-Northern Oquirrh Mountains (Oct 1996).

In terms of human receptors and pathways, based upon a review of the land use
(both at the time of the remedy selection and this review) recreational visitors and
industrial workers are suspected to be the exposure pathways. Exposure is caused
by the inadvertent ingestion of soils with elevated COCs or inhalation of airborne
particulates with the COCs. Based upon a comparison of limited soil data (for the
Dump) to the PRG goals for these receptors, there appears to be a limited risk of
exposure.

At the time of remedial decisions EPA Region 8 made a risk management
determination that there was a potential for ecological impacts from migrating
Dump material into the nearby Middle Canyon Creek. The Creek is utilized by
local fauna as drinking water source (both up and down gradient of the Dump).
Though the ecological risk assessment (noted above) did not specifically addressed
the local fauna and potential for exposure risk in Middle Canyon, EPA’s remedial
decision to have the Dump stabilized was based upon the limited data on lead and
arsenic in comparison to concentrations reported in the ecological risk assessment
that could cause exposure.

46
c. Changes in Toxicity, and Other Contaminant Characteristics: There have been no
changes in the toxicity factors or characteristics for the COCs that were used in the
Preliminary Remediation Goals for Addressing Risk to Human Health From
Exposures to Chemicals in Kennecott Soils (Dec 1999). From an ecological
perspective (as it pertains to the investigation reported in the Ecological Risk
Assessment-Northern Oquirrh Mountains, Oct 1996) changes in toxicity and other
characteristics of the selected COCs needs to be evaluated along with a comparison
of the listed COCs in the 2002 ROD to the concentrations reported in the eco-risk
assessment for the Northern Oquirrh Mountains.

d. Changes in Risk Assessment Methods: No formal risk assessment for human health
was done. Limited comparable eco-risk information was used by EPA Region 8
but not specifically developed for OU18, more specifically Utah Metals Tunnel
Dump.

e. Expected Progress Towards Meeting RAOs: The selected remedy has met the
RAOs selected under the 2002 Record of Decision for the North and South Zones
of Kennecott. As long as current land use remains the same and Kennecott
continues to ensure the slopes of the Utah Metals Tunnel Dump remain stable, the
RAOs will be met.

3. Question C: Has any other information come to light that could call into question the
protectiveness of the remedy?

No weather related events have affected the protectiveness of the reclamation actions or
the current run-on/run-off controls. Previous to the reconstructed run-off control
channel (Photo No. 82&83, Appendix I) located on the western embankment of the
Utah Metals Tunnel Dump, a collection basin (Photo No. 73) for the previously
installed HPDE down spot pipe had been undercut. The new rip-rapped channel was
installed to mitigate this occurrence and has been successful. Dump material (i.e. waste
rock) continues to be limited from impacting the nearby Middle Canyon Creek. The
completion of annual site inspections by Kennecott remains the most current significant
issue (see Chapter VIII, Section C, Table 13). There is no further information that calls
into question the protectiveness of the response work.

Future land use options were inquired about by representatives of Tooele County, Utah.
Though the Utah Metals Tunnel and Utah Metals Tunnel Dump facility of OU18 is
held in ownership by Kennecott, the site has historically and continues to be used for
recreational purposes (though vehicular access to the Dump’s top surface has been
restricted). The pending map of the facility (documenting COCs above pertinent land
use standards, in this case a rationale UU/UE standard) will assist future land planners
when considering a land use change.

4. Technical Assessment Summary

According to the data review, the site inspections, document review and interviews
with Kennecott representatives the response work performed at Utah Metals Tunnel
and Utah Metals Tunnel Dump was successful to mitigate the continued erosion and
migration of Dump material (i.e. waste rock) into Middle Canyon Creek. Current
ownership of the site belongs to Kennecott, who on annual basis is responsible to
47
inspect the integrity of the Dump. Current land use (open space, recreational) is likely
to remain the same into the near future.

No formal risk assessment was done for the response work performed at OU18; as such
no evaluation of the toxicity of the COCs was initially done. Since no formal risk
assessment was performed, a review of risk assessment methodology was not
completed under this five year review.

VIII. Issues

A. OU3 Butterfield Mine, Canyon & Creek, Herriman Residential & Agricultural Lands

1. A summary of issues for OU3 are given in the following table:

Table 11– OU3 Summary of issues
Issue Currently
Affects
Protectiveness
(Y/N)
Affects
Future
Protectiveness
(Y/N) - explain
#1 Up-gradient waste rock piles (if left
uncontrolled) could by erosion impact
downstream remediated areas in Butterfield
Canyon.

N

Y
#2 Trash and general refuse debris was generally
found in the area of Eva’s Pond which was
constructed as a debris basin, as part of the
removal activities at Butterfield Mine.
N N
#3 In the confluence areas of Saints Rest and
Yosemite drainages with Butterfield Canyon
there are buried areas that exceed potentially
applicable unrestricted land use/unrestricted
exposure standards (1200 mg/kg and 100 mg/kg
respectively) for lead and arsenic.
N (protective of
current land
use)
Y(if development
upon these areas is
not overseen by ICs
program)
#4 Some residential properties in Herriman had a
removal action removing the first 18 inches of
soil with elevated lead and arsenic, and were
backfilled. This left elevated lead & arsenic
below surface grade. Mapping of these
properties plus institutional knowledge of their
location is limited.

Y (if
excavations at
these properties
is un-controlled)

Y (if excavations at
these properties is un-
controlled)
#5 Pasture lots or “extended backyards” at the
Herriman Residential properties were not
universally addressed by removal action. It is not
known if such areas would be overseen as part of
the City of Herriman’s ICs program.
Y (if
development
upon these areas
is not overseen
by ICs program)
Y (if development
upon these areas is
not overseen by ICs
program)
#6 ICs program by the City of Herriman is being
revised. UDEQ developed some concerns during
a review of the proposed procedures.
N Y (If changes lessen
restrictions)
#7 No ARARs were listed in the ROD for the
selected ICs remedy for Herriman.
Y (no control
over how
Y (no control over
how excavated soils
48
excavated soils
with elevated
COCs are
managed)
with elevated COCs
are managed)
#8 UDEQ was unable to assess if an ICs program
was ever developed by the engineering and
planning divisions of the Salt Lake County.
Y (if
development
upon these areas
is not overseen
by an ICs
program)
Y (if development
upon these areas is
not overseen by an
ICs program)
#9 Certain redevelopment or new construction
projects may have left elevated concentrations of
lead and arsenic in the near surface soils (City of
Herriman’s ICs program is a “self-certification”
program.)
Y (If current
projects left
elevated lead &
arsenic in
surface and near
surface soils)
Y (If future projects
leave elevated lead &
arsenic in surface and
near surface soils)

B. OU6 Lark Waste Rock & Tailings

1. A summary of issues for OU6 are given in the report is given in the following table:

Table 12– OU6 Summary of issues
Issue Currently
Affects
Protectiveness
(Y/N)
Affects
Future
Protectiveness
(Y/N) - explain
#1 In portions of the Lark Tailings and the
ancillary facilities there is the potential for soils
with lead and arsenic above potentially
applicable unrestricted land use/unrestricted
exposure standards.
N (current land
use applications,
open space and
agricultural, are
not impacted by
known
concentrations
of the COCs)
Y (if land use
changes to
residential, some
exposure might be
possible

C. OU18 Acid Mine Drainage

1. A summary of issues for OU18 are given in the following table:

Table 13– OU18 Summary of issues
Issue Currently
Affects
Protectiveness
(Y/N)
Affects
Future
Protectiveness
(Y/N) - explain
#1 Site delineation map for the Utah
Metals Tunnel and Utah Metals Tunnel
Dump has not been submitted. N
Y (If site ownership
changes and
redevelopment takes
place, potential for
waste rock release
49
into Middle Canyon
Creek.)
#2 Site management reports have been
inconsistently provided to UDEQ.
N Y - Such reports
might document the
need for further
stabilization action.
UDEQ response
would be delayed.

IX. Recommendations and Follow-up Actions

A. OU3 Butterfield Mine, Canyon & Creek, Herriman Residential & Agricultural Lands

1. Butterfield Mine:

UDEQ found the removal area well vegetated and supportive of the recreational land
use. The post removal sampling demonstrated that the area was protective for the
current land use. By reference the Kennecott Utah Copper report entitled Final Report
for Compliance Monitoring of Suspended Solids In Butterfield Creek (dated January
18, 2002; see Appendix C) reports that the post removal surface on average complied
with the lead standard. As noted during the records review, one post removal sample
(BFWX-11, 150 mg/kg arsenic) was found to exceed the potentially applicable
unrestricted land use/unrestricted exposure (UU/UE) standard for arsenic (100 mg/kg).
This sample is located within a relatively steep section of Butterfield Canyon that
primarily is supportive of open space and recreational land use types. As such, this one
location is not found to contribute to a significant risk of exposure. UDEQ
recommends that the waste rock removal project was successful at reducing the risk of
exposure to the public that might make use of this recreational area. Subsequently it is
the recommendation that the Butterfield Mine waste rock removal site does not need to
have another five-year Review.

What future source concerns that remain near this site, where originally beyond the
scope of the response action and left to management by Kennecott through protection
permits (UPDES, including Stormwater, and Groundwater Protection). These permits
are overseen by the DWQ. As part of this five-year review UDEQ assessed
Kennecott’s compliance with the DWQ Groundwater Protection Permit on the Eastside
Collection System, the Stormwater Protection Permit for the up-gradient (of this site)
waste rock dumps and the UPDES discharge permit for the Butterfield Mine Tunnel.
Kennecott was found to be in compliance for the past 5 years (actually since 2001) for
all three permits and their respective limitations. Ultimately if the waste rock dumps
above this site were to migrate (i.e. erode) down to the Butterfield Mine area (and into
the Butterfield Creek) or the Butterfield Mine Tunnel discharge were to fall out of
compliance, corrective action would have to be pursued by Kennecott as required under
these permits. As such, when the Butterfield Canyon/Creek and Herriman sites
undergo subsequent five-year reviews it is recommended that compliance with the
referenced DWQ permits should be assessed.

50
2. Butterfield Canyon and Creek:

UDEQ found the removal area well vegetated and supportive of recreational land use.
The post removal sampling demonstrated that the removal action did leave, under a
backfill cover, 4 locations (sample points SRX-9, SRX-11, SRX-22 & 2SRX-3) at the
confluence of Saints Rest and Butterfield Canyon drainages lead above the potentially
applicable UU/UE standard for lead (1200 mg/kg). Similarly the removal action did
leave, under the backfill cover, 2 locations (sample points YSX-8 & YSX-26) at the
confluence of Yosemite and Butterfield Canyon drainages lead above the potentially
applicable UU/UE standard for lead. Also, the County Road was not removed during
removal, as such tailings are suspected to be located under the road. The Saints Rest
area has approximately 1000 linear feet of road that was not addressed through
removal, and the Yosemite area has approximately 1000 linear feet of road that was not
addressed.

UDEQ has assessed that these two removal areas are protective of current land use
types (i.e. open space and recreational). UDEQ notes that these areas may not be
protective of future land use applications because of the samples exceeding the
potentially applicable UU/UE standards. As such, UDEQ has five recommendations
for the Butterfield Canyon Tailings removal areas.

a. The Agencies render a risk management decision to formally adopt the potentially
applicable UU/UE standards for lead and arsenic (1200 mg/kg and 100 mg/kg
respectively) that were utilized during this review. Comparatively the soils/tailings
mix at the confluence of Saints Rest, Yosemite and Butterfield Canyon drainages
are chemically similar to soils that were observed on agricultural and residential
properties in the Community of Herriman. The residential land use standards used
by the Agencies during the residential removal work in Herriman (1200 mg/kg lead
and 100 mg/kg arsenic) addressed soils similar in chemical composition to those
soils addressed at Saints Rest and Yosemite. As such, UDEQ recommends from a
risk management stand point that the UU/UE standards for lead and arsenic should
be the same as the residential cleanup standards at Herriman.

b. The Agencies coordinate with Kennecott to develop appropriate institutional
controls to ensure that at the time of redevelopment on portions of this site
Kennecott or their successors own, an analysis of whether the land is suitable for
the proposed use is performed with oversight by the Agencies.

c. The Agencies, with assistance from Kennecott, coordinated with Salt Lake County
to develop appropriate institutional controls to ensure that no release or
inappropriate exposure happens at those portions of the site overlain by the County
road or from portions of the site the County has rights too. The Agencies should
also, with assistance from Kennecott, verify land ownership in the areas of the
confluence of Saints Rest, Yosemite and Butterfield Canyon drainages to assess if
other coordination efforts on institutional controls are necessary.

d. The Agencies perform a ARARs analysis during the selection of appropriate
institutional controls for the Saints Rest and Yosemite confluence areas with
Butterfield Canyon and Creek.

51
e. Because of the existence of capped (i.e. soil cover) soils/tailings above the
potentially applicable UU/UE standards for lead within the confluences of Saints
Rest, Yosemite and Butterfield Canyon drainages, UDEQ recommends this site
continue to undergo five-year reviews.

3. Herriman Residential & Agricultural Lands:

As part of this five-year review UDEQ interviewed representatives of the City of
Herriman to ascertain from their perspective the City’s success with implementing the
ICs remedy selected under the Kennecott South Zone 2001 ROD for Operable Units 3,
6, and 7. UDEQ found the City of Herriman implementing the selected remedy, which
is primarily a “self-certification” program under which a property owner/developer
certifies (via the stamp of a certified engineer) that all response work was performed.
The few developments on the agricultural lands that have been initiated within the
City’s jurisdiction have attempted to address existing contaminated soils via
excavation, consolidation on site and cover or excavation and haul to Kennecott’s
Bluewater Repository. Development at pasture lots or extended back yards on the
residential properties has been even more limited. Though noted by the City Engineer
that development on pasture lots (not previously addressed via removal action) does get
overseen through the institutional controls program, the 2001 Record of Decision does
not specify that such review action is required.

As part of this review, the UDEQ agreed to evaluate the proposed City of Herriman
document entitled Development of Contaminated Properties – Procedures of Herriman
City. Though not formally adopted by the City, this document is intended to facilitate
educating interested parties how to proceed with development in light of the lead and
arsenic contamination in the some of the residential and agricultural soils of the City.
The procedures to develop contaminated properties in the City of Herriman are being
implemented, even though the procedures plan drafted by the City has not been
formally adopted under rule. UDEQ (during its assessment of the City guidance
document) found a number of concerns. The general concerns UDEQ has with the
guidance document included:

· Observed discrepancies with defined terminology;

· Partial references to the prescribed land use standards in the 2001 Record of
Decision;

· Incomplete listing of response action documentation that should be submitted
by the applicant (i.e. worker health and safety plan, environmental
controls/decontamination plan, quality assurance project plan, site
management plan, etc.);

· Lack of required environmental inspections for development activities on
impacted lands;

· Lack of requirements necessitating individual developments to ensure that
capped areas will be maintained in perpetuity; and

52
· Lack of requirement for the application of erosion and sediment
environmental engineering controls (fact sheets for such controls were found
to describe the controls but there appeared to be no requirement for their
use).

a. UDEQ recommends that the Agencies coordinate with the City of Herriman to
address the noted concerns and get the procedures plan finalized and published.

The success of previous developments to have addressed the lead and arsenic
contamination in a sufficient manner to prevent future risks to human health or the
environment could not be easily ascertained during the five-year review. Sampling
was considered outside the scope of the review and an evaluation of current records
found incomplete information.

b. UDEQ recommends a limited screening of surface and near surface soils on
selected project properties to assess if redevelopment activities have left soils in the
near surface zone that may cause an impact to human health and the environment,
or be allowed to migrate (i.e. erode). Selected developments for screening level
sampling include: (1) Blackhawk, (2) Western Creek, and the (3) Salt Lake County
Flood Control sewer inlet.

c. UDEQ also recommends offering environmental inspection assistance to the City
of Herriman while it constructs the 126th South By-pass road through the Tuscany
Estates soils repository. Such assistance will help to educate the staff of the City of
Herriman on how to perform such inspections.

d. UDEQ recommends that the Agencies incorporate, as part of a modification of the
selected remedy, the review and oversight of development on pasture lots/extended
back yards for those residential properties that have such extensions to their
property under the selected institutional controls program implemented by the City
of Herriman.

e. The Agencies perform a ARARs analysis to ensure that those federal, state and
local regulations that should be ARARs are included since soils are being
excavated and disposed of within the Community of Herriman.

f. There are agricultural lands impacted with elevated concentrations of lead and
arsenic that are within the jurisdiction of Salt Lake County. In 2000 EPA had
initiated an effort to negotiate with the engineering and planning divisions of Salt
Lake County to develop an ICs program (similar to what the City of Herriman had
done). Said ICs program would allow the Salt Lake County to ensure that property
owners and/or developers were addressing inappropriate concentrations of lead and
arsenic (for the intended land use) at the time of redevelopment. During this five-
year review UDEQ was not able to assess if such an ICs program was ever
developed by the Salt Lake County. UDEQ recommends coordinating with EPA to
educate the staff of the Salt Lake County engineering and planning divisions on an
ICs plan and assisting them with developing and implementing an ICs plan.

g. UDEQ’s recommends that this portion of OU3 continue to receive five-year
reviews since soils with elevated lead and arsenic above potentially applicable
53
UU/UE standards will remain buried or at the surface on the residential and
agricultural lands within the community of Herriman for some time.

4. A summary of recommendations for OU3 are given in the following table:

Table 14– Summary of OU3 Recommendations
Affects
Protectiveness
(Y/N)
Issue -
Entity
Recommendation/
Follow-up Action
Party
Responsible
Milestone
Date
current future
#1
Continue to evaluate
Kennecott’s
compliance with
DWQ permits for the
waste rock dumps,
during subsequent
five-year review
investigations.
UDEQ 2nd Five Year
Review
Completion -
October 2014 N Y
#2
Notify the Salt Lake
County Public Works
and park/rec
divisions, to see if
they can facilitate a
cleanup. Recommend
as a local service
project to youth
group organizations.
UDEQ June 2010
N N
#3
Identify performance
standards for residual
metals
concentrations
in soil. If residual
contamination meets
performance
standards, the
area will be
identified as
UU/UE. If residual
contamination
exceeds performance
standards,
institutional controls
must be
implemented.
UDEQ &
EPA,
coordinating
with
Kennecott
and Salt Lake
County
June 2010
N Y
#4
Coordinate with the
City of Herriman to
ascertain if maps, of
the residential
properties with
UDEQ &
City of
Herriman
Notification
by City that
maps of
capped lots
exist and are
Y Y
54
elevated
contaminants of
concern exist below
current surface
grade, are held by the
City Planning &
Zoning Department.
Ensure mechanism to
maintain institutional
knowledge.
held by the
City - June
2010
#5
Assure that pasture
lot and “extended
backyard”
redevelopment falls
within the scope of
oversight by the City
of Herriman under
the City’s ICs
program.
UDEQ &
City of
Herriman
Notification
by City that
pasture land
redevelopme
nt does
require
environmenta
l assessment
- June 2010
Y Y
#6
Provide the City of
Herriman with
comments
concerning
information and
procedural gaps
observed by UDEQ
in the proposed
revised ICs program.
UDEQ &
City of
Herriman
Provide
comments on
the proposed
ICs
procedures
plan – July
2010.
N Y
#7
Perform an ARARs
analysis and
reevaluate
applicability for the
ICs remedy in light
of excavations being
performed at the
agricultural
properties
UDEQ &
EPA,
coordinate
with the City
of Herriman
June 2010
Y Y
#8
Initiate negotiations
with the Salt Lake
County Engineering
and Planning
Divisions to assist
with the development
of appropriate ICs
program.
UDEQ &
EPA
Negotiation
start – June
2010

IC
Implementati
on - TBA
Y Y
#9
Perform a limited
screening (via
collected soil
samples and/or X-ray
Fluorescence soil
UDEQ Develop
sampling and
analysis plan
– June 2010

Y
(depende
nt upon
results)
Y
(depende
nt upon
results)
55
screening) to
ascertain the lead and
arsenic concentration
in surface and near-
surface soils at
selective properties.
Negotiate
site access –
July 2010

Sample –
August 2010
#10
Continue five-year
reviews
UDEQ Five years
from the
completion
of the 1st five
year report
N N

B. OU 6 Lark Waste Rock & Tailings

1. Lark Waste Rock:

As noted during the review, the Lark Waste Rock piles were removed completely. The
material removed was placed on the Eastside Waste Rock Dumps of the Bingham
Canyon Mine, which are located behind the Eastside Collection System. Twelve waste
rock piles were removed completely to native soils underneath the piles, to achieve a
post removal surface of 1000 mg/kg for lead and 100 mg/kg for arsenic. As delineated
in the post removal reports, Table 9 above documents the average lead and arsenic
concentrations in post removal samples per pile. This review determined that post
removal samples were below the potentially applicable unrestricted land
use/unrestrictive exposure (UU/UE) standards for lead and arsenic (1200 mg/kg and
100 mg/kg respectively).

At this time, UDEQ acknowledges that the Lark Waste Rock removal project was
successful to mitigate current and potential long term risk concerns associated with the
waste. UDEQ recommends that the areas of the waste rock removal areas do not need
subsequent five-year reviews.

2. Lark Tailings:

The inspection of this portion of OU6 found the vegetative cover intact and the site
supportive of current land use. A fence along the site’s boundaries (installed for
purposes to protect the reseeding effort) was also found to be relatively intact (one
intrusion through the fence exists near the Southeast corner of the Lark Tailings
reclamation area where the Kennecott Land haul road transects the sites southern
boundary). Though it was noted from the response work documentation that some
“hotspot” removal work (no data was available) was performed, in general the Lark
Tailings area was primarily regraded, covered and then revegetated. As noted by
Kennecott representatives during the records review, the pre-grading characterization
data documented lead concentrations ranging from 3 mg/kg to 8700 mg/kg and arsenic
concentrations ranging from 5 mg/kg to 220 mg/kg. Prior to covering the regraded
Lark Tailings reclamation area, large scale composite samples were collected and
analyzed for lead and arsenic. This second characterization effort delineated a lead
concentration on the regraded slopes ranging from 13 mg/kg to 170 mg/kg and an
arsenic concentration ranging from 12 mg/kg to 120 mg/kg. Currently, it is suspected
56
that some of the higher lead and arsenic concentrations still remain onsite under the
covered, regraded slopes.

UDEQ has assessed that the response work implemented at the Lark Tailings area
(Lark Tailings reclamation area) is supportive of current land use practices (i.e. open
space, agricultural). Potentially applicable open space and agricultural land use
standards could and were drawn from the OU3 portion of the September 2001 ROD
during this review to provide for a comparison of the pre-cover sample data (open
space – lead 3000 to 10,000 mg/kg and arsenic 250 to 300 mg/kg; agricultural – lead
10,000 mg/kg and arsenic 300 mg/kg). The open space and agricultural land use
standards used during this review by UDEQ were selected pursuant to the explanation
provided under subpart “a” (second paragraph) of this recommendation. At this time,
UDEQ notes that the Lark Tailings may not be protective of future land use
applications because of the mixed soils/tailings having the potential to exceed the
potentially applicable UU/UE standards for lead and arsenic (noted in Section C of this
chapter). As such, UDEQ has four recommendations for the Lark Tailings area.

a. The Agencies render a risk management decision to formally adopt the potentially
applicable UU/UE standards for lead and arsenic (1200 mg/kg and 100 mg/kg
respectively) that were utilized during this review.

The soils/tailings mix at OU6 Lark Tailings was derived from the milling of an ore
body by the Ohio Copper Company (from 1909 to 1919) that was primarily a
porphyry copper deposit with a low lead and arsenic concentration.
Comparatively, the ore mined and milled at the Revere operations in Butterfield
Canyon processed a skarn ore deposit that was high for lead and silver (phone
interview with Mr. Brian Vinton, NAMS, April 28, 2009). The residential land use
standards used by the Agencies during the residential removal work in the
Community of Herriman (1200 mg/kg lead and 100 mg/kg arsenic) were developed
in light of a risk assessment using samples from the Butterfield Canyon site,
samples that had a higher potential for elevated lead and arsenic concentrations. As
such, UDEQ recommends from a risk management stand point that the UU/UE
standards for lead and arsenic for the Lark Tailings area should be the same as the
potentially more conservative residential cleanup standards developed for the
Community of Herriman.

b. The Agencies coordinate with Kennecott to develop appropriate institutional
controls to ensure that at the time of redevelopment on portions of OU6 - Lark
Tailings Kennecott or their successors own, an analysis of whether the land is
suitable for the proposed use is performed with oversight by the Agencies.

c. The Agencies perform a ARARs analysis during the selection of appropriate
institutional controls for the Lark Tailings reclamation area.

d. Because of the existence of regraded soils/tailings above the potentially applicable
UU/UE standards for lead within OU6 Lark Tailings, UDEQ recommends this site
continue to undergo five-year reviews.

57
3. Lark Waste Rock and Tailings Ancillary Facilities:

The ancillary sites, Randolph Peterson Gate, Mascotte Ditch, Bastian Ditch, Midas
Creek Silos Area, the area between Mascotte Pond and Midas Creek Silos, Southeast
Area, and the Lone Tree Area, received some characterization and response actions
during the Lark Tailings response work. A review of the characterization or post
response data for Randolph Peterson Gate, Midas Creek Silos area, and the Southeast
and Lone Tree Areas delineated lead and arsenic concentrations that are supportive of
the current land use (i.e. open space or agricultural, standards for which were drawn for
comparison from the Sept. 2001 ROD OU3 Chapter). Characterization data for the
Mascotte Ditch, Bastian Ditch, portions of Midas Creek Silos area, the area between
the Mascotte Pond and Midas Creek Silos were more limited but are suspected to be
supportive of the current land use (open space or agricultural) after a review of the
history of the site. As noted there is the potential to have soils at these ancillary sites
(except for the Lone Tree site) that could exceed the potentially applicable lead and
arsenic UU/UE standards used during the review (and drawn from the OU3 Chapter of
the September 2001 ROD).

At this time, UDEQ notes that the ancillary sites may not be protective of future land
use applications because of the mixed soils/tailings having the potential to exceed the
potentially applicable UU/UE standards for lead and arsenic. As such, UDEQ has four
recommendations for the Lark Tailings area.

a. The Agencies render a risk management decision to formally adopt the potentially
applicable UU/UE standards for lead and arsenic (1200 mg/kg and 100 mg/kg
respectively) that were utilized during this review.

The soils/tailings mix at OU6 Lark Tailings was derived from the milling of an ore
body by the Ohio Copper Company (from 1909 to 1919) that was primarily a
porphyry copper deposit with a low lead and arsenic concentration.
Comparatively, the ore mined and milled at the Revere operations in Butterfield
Canyon processed a skarn ore deposit that was high for lead and silver (phone
interview with Mr. Brian Vinton, NAMS, April 28, 2009). The residential land use
standards used by the Agencies during the residential removal work in the
Community of Herriman (1200 mg/kg lead and 100 mg/kg arsenic) were developed
in light of a risk assessment using samples from the Butterfield Canyon site,
samples that had a higher potential for elevated lead and arsenic concentrations. As
such, UDEQ recommends from a risk management stand point that the UU/UE
standards for lead and arsenic for the Lark Tailings area ancillary sites should be
the same as the potentially more conservative residential cleanup standards
developed for the Community of Herriman.

b. The Agencies coordinate with Kennecott to develop appropriate institutional
controls to ensure, at the time of redevelopment on portions of ancillary sites that
exceed applicable UU/UE standards for lead and arsenic that Kennecott or their
successors own, an analysis of whether the land is suitable for the proposed use is
performed with oversight by the Agencies.

c. The Agencies perform an ARARs analysis during the selection of appropriate
institutional controls for the Lark Tailings ancillary sites Randolph Peterson Gate,
58
Mascotte Ditch, Bastian Ditch, Midas Creek, Midas Creek Silos area, Southeast
and Lone Tree Areas.

d. Because of the existence of regraded soils/tailings above the potentially applicable
UU/UE standards for lead within OU6 Lark Tailings, UDEQ recommends this site
continue to undergo five-year reviews.

4. A summary of recommendations for OU6 are given in the following table:

Table 15– OU6 Summary of OU6 Recommendations
Affects
Protectiveness
(Y/N)
Issue -
Entity
Recommendation/
Follow-up Action
Party
Responsible
Milestone
Date
current future
#1
Identify performance
standards for residual
metals
concentrations
in soil. If residual
contamination meets
performance
standards, the
area will be
identified as
UU/UE. If residual
contamination
exceeds performance
standards,
institutional controls
must be
implemented.

Develop ICs program
to control future land
use changes.

Perform a ARARs
analysis.

UDEQ &
EPA,
coordinating
with
Kennecott
June 2010
N Y

C. OU18 Acid Mine Drainage

1. Utah Metals Tunnel and Utah Metals Tunnel Dump:

UDEQ found that stabilization and reconstruction efforts implemented by Kennecott
since 2000, to have been successful at preventing the continued migration of waste rock
material from the Utah Metals Tunnel Dump into Middle Canyon Creek. The site
access barriers were viewed to be successful by UDEQ to prevent vehicular traffic from
59
disturbing the revegetation effort along the top surface of the Utah Metals Tunnel
Dump. The piping of discharge water from the Utah Metals Tunnel off the Dump and
delivery to the local irrigation company’s collection system (since 2006) was found to
be successful to prevent the erosion of the Utah Metals Tunnel Dump’s top surface.
Lastly, the reconstructed drainage channel from the top of the Dump down the western
slope of the Dump was found by UDEQ to be a robust structure for future storm events.

No known complaints have been received from the irrigation company to date. The
land use at the site remains as it was during the selection of the remedy
(recreational/open space) and thus the selected remedy remains protective. Because the
waste rock still has contaminants of concern (i.e. 2000 mg/kg lead, eco risk) above
unrestricted land use standards, UDEQ recommends this site receive a subsequent Five
Year Review.

As part of the stabilization effort, under the September 2002 Kennecott North Zone &
South Zone ROD Kennecott was required to submit annual inspection reports on the
stabilization controls and water management controls at this site. Such reports were to
be submitted to UDEQ. As part of the selected remedy a map of this site’s location for
use by land planners in the future (during proposed redevelopment actions) was to be
submitted to the EPA and UDEQ as part of the larger Kennecott North Zone mapping
exercise. This larger exercise is tasked to delineate the location of capped or covered
waste left in place across the North Zone and portions of the South Zone of the
Kennecott site. To date such map has not been received. UDEQ recommends that this
map and site management exercise get wrapped up in the pending Site Wide
Management Plan for waste left in place (being drafted during the negotiations of the
North Zone & South Zone consent decree). UDEQ further recommends that this
portion of OU18 continue to undergo five-year reviews while soils continue to be
present above the potentially applicable UU/UE standards, for the COC in question (i.e.
lead).

2. Other Tunnels and Dumps:

The other tunnels (i.e. Apex (Parvenu), Bingham West Dip, Adamson, Copper Boy,
Spring Canyon Tunnels, Upper Bruneau, and Helen B) and waste rock dump (i.e.
Bingham West Dip) are located in areas still currently being used as open space or
industrial land use. Subsequent to the observance of no land use change plans being
proposed the UDEQ assessed that the original remedy specified for these sites is still
adequate and protective. As noted in the records review, Kennecott has maintained
compliance with its UPDES permit limitations in Pine Canyon (the primary drainage
for the tributaries these tunnels and dump are located within. This portion of OU18
does not need to continue to undergo five year reviews.

3. A summary of recommendations for OU18 are given in the following table:

60
Table 16– Summary of OU18 Recommendations
Affects
Protectiveness
(Y/N)
Issue Recommendation/
Follow-up Action
Party
Responsible
Milestone
Date
current future
#1
Submission of map
delineating the
location of the Utah
Metals Tunnel &
Utah Metals Tunnel
Dump site in Middle
Canyon.
Kennecott 1Please see
footnote at
bottom of
page N Y
#2
Reporting
requirement to be
stated within the
pending Site Wide
Management Plan.
Kennecott 1Please see
footnote at
bottom of
page
N Y
#10
Continue five-year
reviews for the Utah
Metals Tunnel and
Utah Metals Tunnel
Dump portion of
OU18.
UDEQ Five years
from the
completion
of the 1st
five year
report
N N

X. Protectiveness Statements

A. OU3 Butterfield Mine, Butterfield Canyon & Creek, Herriman Residential and
Agricultural Lands (City of Herriman and Salt Lake County):

The remedy for OU3 is not protective because: (1) potential redevelopment (i.e. change in
land use) on portions of the operable unit is not managed through an ICs program, (2) the
current ICs program in the City of Herriman is a “self certification” program which lacks
independent verification of statements made by building permit applicants that a site is
protective for the intended land use, (3) there are no listed ARARs for the selected remedy.

There are portions of OU3 which are in compliance with the intent of the selected remedy
or the goals of the previous removal actions. For example, in Butterfield Canyon (Mine,
Canyon and Creek) source controls for the up-gradient waste rock dumps are being
maintained and operated in compliance with the Utah Groundwater Water Protection and
UPDES permit limitations. The permits have corrective action requirements associated
with them to address out-of-compliance conditions if they arise. The removal actions in the
Canyon (for the mine waste rock and tailings sites) were effective to remediate this portion
of OU3 and to reduce the risk of exposure for the intended and current land use (i.e. open
space, recreational).

1 Submission of a map and discussion of reporting requirements is subject to the Site Wide Management
Plan for waste left in place being drafted and negotiated during the negotiation of the North Zone & South
Zone consent decree. The milestone date is subject to approval of the Site Wide Management Plan under
the noted consent decree.
61

The following actions need to be taken to ensure protectiveness where soils exceed selected
land use standards listed in the 2001 Kennecott South Zone ROD:

1. UDEQ and EPA need to coordinate with the Salt Lake County divisions of engineering
and planning to assist with the development of an ICs program (with a listing of pertinent
ARARs) that is effective to ensure the proper management of soils with elevated lead and
arsenic above selected land use standards when agricultural properties within the County
jurisdiction undergo redevelopment.

2. UDEQ and EPA need to coordinate with the City of Herriman to:
i. Screen surface and near surface soils in known disturbed locations on redeveloped
properties within Herriman’s jurisdiction.
ii. Provide comments and assist with the finalization of the document entitled
Development of Contaminated Properties – Procedures of Herriman City to ensure
proper management of soils with elevated lead and arsenic above selected land use
standards when agricultural properties within the City’s jurisdiction undergo
redevelopment. This effort shall also include a listing of pertinent ARARs.
iii. Ensure capped or un-remediated residential properties and residential pasture
lots/extended backyards are documented (i.e. mapped), so the City can ensure
redevelopment in these areas will fall under the scope of their ICs program.

3. UDEQ and EPA need to work with Kennecott and Salt Lake County to develop ICs for
the confluence areas of Saints Rest and Yosemite drainages with Butterfield Canyon.
This action will ensure that if the current land use is changed, the soils in the confluence
areas are investigated to determine if they support the intended land use.

B. OU6 Lark Waste Rock & Tailings and Ancillary Facilities:

The remedy for the Lark Waste Rock removal project is protective of current (industrial,
open space) and potentially applicable future land use (open space, agricultural, residential)
because the response work removed materials above the cleanup goals. The remedy for
Lark Tailings (re-grading and cover) and the ancillary facilities (some characterization, some
hotspot removals) is protective of current land use applications (i.e. open space and
agricultural).

Development of ICs for the Lark Tailings area and ancillary facilities will ensure that if (in
the future) the land use changes, the soils at these two sites are investigated to determine if
they support the intended land use.

C. OU18 Acid Mine Drainage:

The remedy at Operable Unit 18 (more specifically the Utah Metals Tunnel and Utah Metals
Tunnel Dump, and other tunnels and dump located along the western face of the Oquirrh
Mountains) is protective of human health (based upon current land use, open
space/recreational) and the environment. Response action source controls are in place at the
Utah Metals Tunnel and Utah Metals Tunnel Dump, and are being maintained and operated
in compliance with the September 2002 North Zone & South Zone ROD. These controls are
being monitored by Kennecott. The response action (stabilization of the waste rock in the
dump and prevention of erosion) remains intact and there were no new impacts to the
remediated area.
62

XI. Next Review

This review was required by statute. The next review will be conducted within five years of the
completion of this five-year review report. The completion date is the date of the signature
shown on the signature cover attached to the front of the report.

Bingham Pit
HERRIMAN RESIDENTIAL AND AGRICULTURAL
BUTTERFIELD WASTE ROCK
BUTTERFIELD CANYON CREEK TAILINGS
HOLT MILL
REVERE MILLST JOES MINE
BROOKLYN MILL
YOSEMITE MILL
QUEENS MINE & MILLBLACKJACK GULCH MINES
BUTTERFIELD MINE ADIT
WATER SUPPLY TUNNEL DUMP
YOSEMITE GULCH/ SAINTS REST MINES
Herriman City
South Jordan City
Riverton City
Bluffdale City
KENNECOTT SOUTH ZONE
OPERABLE UNIT 3
BUTTERFIELD CANYON
AND HERRIMAN
ENVIRONMENTAL
RESTORATION GROUP
Drawing Number: OU3_72309
Date: 7/09
Drawn By: JI
Project Mgr: BV
Rev:

0 8,0004,000
Feet
111
N e w B i n g h a m H w y
O l d B i n g h a m H w y
11800 S
T R A V E R S E M O U N T I A N S
OU3
BUTTERFIELD WASTE ROCK
HERRIMAN RESIDENTIAL AND AGRICULTURAL
BUTTERFIELD CANYON CREEK WASTE ROCK TAILINGS
HISTORIC MILLING AND MINING LOCATIONS
Note: All areas and site are in
approximate location.

Copperton
Bingham Pit
MIDAS POND
FORTUNE
MILL
LONE TREE SITE
BINGHAM & MASCOTTE
TUNNELS
NEW MAMMOTH
MILL
OLD BINGHAM
TUNNEL
EASTSIDE RESERVOIR
COPPER GULCH
MINES
DALTON &
LARK MILL
COPPER CREEK
AND GULCH
OHIO COPPER
COMPANY MILLS
MIDAS CREEK &
SILO AREA
STATE MOTORCYCLE PARK
(LARK TAILINGS)
Herriman City
West Jordan City
South Jordan City
KENNECOTT SOUTH ZONE
OPERABLE UNIT 6
LARK WASTE ROCK AND TAILINGS
ENVIRONMENTAL
RESTORATION GROUP
Drawing Number: OU6_72309
Date: 7/09
Drawn By: JI
Project Mgr: BV
Rev:

0 6,0003,000
Feet
111
11800 S
Old Bingham Hwy.
OU6 - LARK WASTE ROCK & TAILINGS
EAST SIDE BINGHAM CANYON DUMPS
LARK TAILINGS
LARK WASTE ROCK
MASCOTTE POND
PROLER
RANDOLPH PETERSON GATE
HISTORIC MINING & MILLING OPERATIONS
DALTON AND LARK RAILROAD
MASCOTTE DITCH
Note: All sites and areas are shown
in approximate locaton.
South Jordan City
Riverton City
West Jordan City
Herriman City
KENNECOTT SOUTH ZONE
OPERABLE UNIT 7
SOUTH JORDAN
EVAPORATION PONDS
ENVIRONMENTAL
RESTORATION GROUP
Drawing Number: OU7_72309
Date: 7/09
Drawn By: JI
Project Mgr: BV
Rev:

0 4,0002,000
Feet
11800 S
Old Bingham Hwy.
Bangerter Hwy.
SOUTH JORDAN
EVAPORATION PONDS
Daybreak Area
OU7 - SOUTH JORDAN EVAPORATION PONDS
(APPROXIMATE LOCATION)
Copperton
BASTIAN SINK
KENNECOTT SOUTH ZONE
OPERABLE UNIT 17
BASTIAN SINK
ENVIRONMENTAL
RESTORATION GROUP
Drawing Number: OU17_72309
Date: 7/09
Drawn By: JI
Project Mgr: BV
Rev:

0 3,0001,500
Feet
Old Bingham Hwy.
11800 S
111
OU17 - BASTIAN SINK
(APPROXIMATE LOCATION)

Copperton
Bingham Pit
Tooele
WATER SUPPLY TUNNEL DUMP
HELEN B
ARMSTRONG
COPPER BOY
HIGHLAND BOY
UPPER BRUNEAU
SPRING CANYON
APEX (PARVENU)
BINGHAM WEST DIP
WATER SUPPLY TUNNEL
KENNECOTT SOUTH ZONE
OPERABLE UNIT 18
ACID MINE DRAINAGE
(TOOELE CO. AREAS)
ENVIRONMENTAL
RESTORATION GROUP
Drawing Number: OU18_72309
Date: 7/09
Drawn By: JI
Project Mgr: BV
Rev:

0 10,0005,000
Feet
111
OU18 - ACID MINE DRAINAGE (TOOELE CO. AREA) SITES
(APPROXIMATE LOCATIONS)