Re: Remedial Action Work Plan – Revision 1 United Verde ... RAWP Revision 1... · 7560 N La...

GHD 7560 N La Cholla Blvd Tucson, Arizona 85741 USA T 520 623 9221 F 520 623 3065

October 9, 2018 Reference No. 11102656 Mr. John Patricki Arizona Department of Environmental Quality Remedial Projects Section 1110 W Washington St., 6th Floor Phoenix, Arizona 85007 Dear Mr. Patricki: Re: Remedial Action Work Plan – Revision 1

Voluntary Remediation Program United Verde Soil Program Clarkdale, Arizona VRP Site Code: 512101-00

As requested, GHD Services, Inc. (GHD), on behalf of Freeport Minerals Corporation (FMC), is providing

one electronic copy (PDF) and one bound copy of the final version of Revision 1 to the Remedial Action

Work Plan (RAWP), United Verde Soil Program (UVSP), Clarkdale, Arizona (approved October 5, 2018).

Should you have any questions or comments regarding this document, please feel free to contact Alicia

Voss at (602) 316-5467 or myself at (520) 460-6335 or via email at [email protected].

Sincerely,

GHD

Charles Janson

CJ/trc/Patr-003

Encl.

cc: Alicia C. Voss, Freeport Minerals Corporation

Remedial Action Work Plan – Revision 1 Voluntary Remediation Program United Verde Soil Program

Clarkdale, Arizona

VRP Site Code: 512101 00

Freeport Minerals Corporation

GHD | 7560 N La Cholla Blvd Tucson, Arizona 85741 USA

11102656 | 001 | Report No 4 | October 2018

GHD | Freeport Minerals Corporation - Remedial Action Work Plan | 11102656 (4) | Page i

Table of Contents

1. Introduction 1

1.1 Soil Cleanup Objective .............................................................................................................. 2

2. Project Administration 2 2.1 Organization .............................................................................................................................. 2

2.2 Schedule ................................................................................................................................... 3

3. Cleanup Activities 3 3.1 Property-Specific Cleanup Activities ......................................................................................... 3

3.1.1 Property Access....................................................................................................... 4 3.1.2 Town of Clarkdale Permits ...................................................................................... 4 3.1.3 Pre-Excavation Area Preparation ............................................................................ 4 3.1.4 Excavation Activities ................................................................................................ 5 3.1.5 Loading Excavated Materials .................................................................................. 7 3.1.6 Noise Control ........................................................................................................... 8 3.1.7 Dust Control ............................................................................................................. 8 3.1.8 Access for Property Residents ................................................................................ 8 3.1.9 Decontamination Procedures .................................................................................. 9 3.1.10 Backfill and Revegetation of Excavated Areas ........................................................ 9 3.1.11 Follow-Up Activities ............................................................................................... 10 3.1.11.1 Photo Documentation ............................................................................................ 10 3.1.11.2 Repair Work ........................................................................................................... 10 3.1.11.3 Property Inspection ................................................................................................ 11 3.1.11.4 Reporting ............................................................................................................... 11

3.2 Soil Repository Area ............................................................................................................... 11

3.3 Soil Transportation .................................................................................................................. 12

4. Construction Management Considerations 13

4.1 Scheduling of Cleanup Properties .......................................................................................... 13

4.2 Construction Quality Assurance/Quality Control .................................................................... 14

4.3 Health and Safety ................................................................................................................... 14

5. Reporting 14 5.1 Cleanup Reporting .................................................................................................................. 14

5.2 Data Reporting ........................................................................................................................ 14

5.2.1 Weekly Documentation .......................................................................................... 15 5.2.2 Monthly Reporting.................................................................................................. 15

5.3 Final Report ............................................................................................................................ 15

6. References 15

Figure Index Figure 1 Study Area Location

GHD | Freeport Minerals Corporation - Remedial Action Work Plan | 11102656 (4) | Page ii

Figure 2 Soil Repository Area

Table Index

Table 1.1 Cleanup Levels ......................................................................................................................... 2

Appendix Index Appendix A Draft Remedial Action Work Plan Correspondence

Appendix B Fugitive Dust Control Plan

Appendix C Sampling Data to Support Soil Repository Location

Appendix D Soil Repository Design, Construction and Operations Plan

GHD | Freeport Minerals Corporation - Remedial Action Work Plan | 11102656 (4) | Page iii

List of Acronyms

ADEQ Arizona Department of Environmental Quality

AOC Area of Contamination

APP Aquifer Protection Permit

ARS Arizona Revised Statute

BADCT Best Available Demonstrated Control Technology

BSA Backfill Staging Area

CC Construction Contractor

CFR Code of Federal Regulations

CGP Construction General Permit

CHSC Contractor’s Health and Safety Coordinator

CPC Construction Project Coordinator

EPA United States Environmental Protection Agency

FDCP Fugitive Dust Control Plan

FMC Freeport Minerals Corporation

HASP Health and Safety Plan

HDPE High-density polyethylene

HELP Hydrologic Evaluation of Landfill Performance

mg/kg milligrams per kilogram

PCCR Property Cleanup Completion Report

QA/QC Quality Assurance/Quality Control

QAPP Quality Assurance Project Plan

RAWP Remedial Action Work Plan

SAP Sampling and Analysis Plan

SWPPP Stormwater Pollution Prevention Plan

TCs Target Constituents

VRP Voluntary Remediation Program

UVSP United Verde Soil Program

GHD | Freeport Minerals Corporation - Remedial Action Work Plan | 11102656 (4) | Page 1

1. Introduction

This Remedial Action Work Plan (RAWP) presents implementation details for soil

remediation (i.e., cleanup) activities to be performed by Freeport Minerals Corporation (FMC) for

residential, non-residential, and publicly-owned developed properties near the former smelter

operations in Clarkdale, Arizona as shown on Figure 1.

The United Verde Copper Company (United Verde) operated a copper smelter northwest of

Clarkdale, Arizona, from 1915 to 1932. The smelter was reopened in 1935 when Phelps Dodge

Corporation purchased United Verde and continued to operate until 1953. FMC is the corporate

successor to Phelps Dodge Corporation.

Because the copper smelter operated in an era before emissions control equipment was commonly

used, historical air emissions from the smelter may have deposited metal-bearing particles on

nearby soil. FMC has elected to enter into the Arizona Department of Environmental

Quality's (ADEQ) Voluntary Remediation Program (VRP) to address the potential that historical

smelter operations may have contributed to elevated metal(s) concentrations in soil on properties

near the former smelter operations (Study Area). Under the VRP, FMC will perform a soil

characterization and remediation program within the Study Area shown on Figure 1. The soil

characterization and remediation work performed by FMC under the VRP in Clarkdale is referred to

as the United Verde Soil Program (UVSP).

The Study Area includes properties most likely to have been affected by historical air emissions (the

primary off-site transport mechanism for metal(s) associated with the United Verde operations) due

to the properties’ proximity to historical smelter operations. This Study Area was approved by ADEQ

as part of FMC’s VRP application. Provision is made for adjustments in the Study Area if warranted

based on the data collected under the ADEQ-approved Sampling and Analysis Plan (SAP)(GHD,

2015a). The process for evaluating the Study Area data to determine whether the Study Area needs

to be expanded is outlined in Section 1.4 of the SAP.

The UVSP will give owners of eligible residential, non-residential (e.g., commercial, etc.), and public

properties (e.g., schools, parks, etc.) within the Study Area the opportunity to have the soil on their

properties tested for certain smelter-related metals (i.e., target constituents [TCs]) and, if necessary,

remediated (i.e., soil removed and replaced, hereinafter referred to as "cleanup").

Soil sampling for the UVSP began in May 2016 and is expected to continue through the duration of

the UVSP. Sampling is being performed in accordance with the SAP and the Quality Assurance

Project Plan, United Verde Soil Program (QAPP) (GHD, 2015b), which were approved by ADEQ on

October 23, 2015. The sampling is designed to determine representative concentrations of arsenic,

copper, lead, tin, zinc and boron for properties in the Study Area for comparison to site-specific

cleanup levels that have been established for the UVSP by ADEQ.

FMC provided a draft RAWP to ADEQ for review in October 2016. The draft RAWP was reviewed

by ADEQ, and FMC received comments from ADEQ in a letter dated December 8, 2016. The letter

included comments from four interested parties (Town of Clarkdale, Arizona; National Park Service;

Yavapai County; and Geneva Saint-Armour). FMC provided ADEQ a letter response to thecomments titled Response to Comments Draft Remedial Action Work Plan (RAWP) United Verde


Soil Program, Clarkdale, Arizona on June 30, 2017. FMC received a letter from ADEQ on October

17, 2017 titled Review of Responses to Comments Draft Remedial Action Work Plan United Verde Soil Program, Clarkdale, Arizona. This RAWP incorporates the comments and revisions identified in

the October 17, 2017 ADEQ Letter. Appendix A contains the correspondences between FMC and

ADEQ.

1.1 Soil Cleanup Objective

The objective of the UVSP cleanup activities is to excavate and replace soil within individual use or

yard areas within a given property where soil concentrations of arsenic, copper, lead, tin, zinc or

boron exceed the cleanup levels approved by ADEQ to ensure that post-cleanup average metals

concentrations no longer exceed the cleanup levels. The purpose of this RAWP is to provide the

specific implementation details for achieving that objective. The cleanup levels for the UVSP are

included in Table 1.1 below.

Table 1.1 Cleanup Levels

Target Constituent Cleanup Level by Land Use (mg/kg)

Residential Non-Residential

Arsenic (As) 30 30

Copper (Cu) 9,000 41,000

Lead (Pb) 425 800

Tin (Sn) 47,000 610,000

Zinc (Zn) 23,000 310,000

Boron (B) 16,000 200,000

2. Project Administration

The project administration activities for the cleanup program will include:

• Coordination among representatives of FMC, ADEQ, Construction Project Coordinator (CPC),

Construction Contractors (CCs), and Town officials.

• Technical oversight of project activities.

• Administration of the CCs.

2.1 Organization

The cleanup program organization will provide consistent management of the cleanup activities and

integration with the ongoing sampling program. The key positions for this organization are:

• FMC Project Manager

• CPC

• CCs

• ADEQ


These key positions have been developed to ensure that the organization, objectives, functional

activities, quality assurance/quality control (QA/QC) activities, and data reporting are managed and

implemented in a manner that meets the requirements of this RAWP. Assignment of the CPC and

CCs will be made by FMC with notification to ADEQ.

The FMC Project Manager will have responsibility for coordinating with ADEQ on the overall RAWP project activities. The CPC is responsible for coordinating with FMC, the CCs, the property owner,

and ADEQ in the field. The CPC is responsible for ensuring that the CCs implement the cleanup

activities in accordance with this RAWP and the QAPP (GHD, 2015b). The CPC is also responsible

for coordinating and documenting the cleanup activities.

2.2 Schedule

The cleanup of individual properties will be prioritized as described in Section 4.1. After the priority

of the property is determined, cleanup activities will be scheduled to facilitate logistics and use of

equipment. Properties will be scheduled for cleanup after access is received and, when possible,

generally grouped into neighborhoods to enable the crews to perform required activities and reduce

disruption to the neighborhood. The progress of the cleanup program will be documented in monthly

progress reports to ADEQ issued by the FMC Project Manager or the CPC. Specific details

regarding progress reporting are described in Section 5.2.

3. Cleanup Activities

In general, the UVSP soil cleanup activities will include:

• excavation of soils that have concentrations of arsenic, copper, lead, tin, zinc or boron in

excess of ADEQ approved cleanup levels;

• replacement of those excavated soils with clean backfill;

• replacement of landscaping with materials that, unless otherwise approved by the property

owner, are comparable to the pre-existing conditions; and

• temporary and final management of the excavated soils.

Implementation details for the above activities are provided in this section. Properties identified as

containing areas with soil exceeding the ADEQ cleanup levels that will not be remediated may

include areas that present potentially significant safety or property damage concerns, such as

deteriorating retaining walls. If future activities/repairs are completed by the property owner to

adequately address the concerns, FMC will consider soil remediation at that time.

3.1 Property-Specific Cleanup Activities

This section presents a description of cleanup construction activities to be performed at individual

properties. Included in this section are the details for obtaining access, pre-excavation yard

preparation, excavation activities, noise control, dust control, maintaining access for the property

residents, decontamination procedures, backfill and revegetation procedures, and follow-up

activities.


3.1.1 Property Access

Cleanup construction activities at a particular property cannot proceed until a property owner has

signed an access agreement for cleanup. If the property is occupied by a tenant instead of the

owner, the tenant may also be requested to sign the access agreement. However, FMC will

consider moving forward without the tenant access agreement if so directed by the property owner.

The cleanup access agreement is separate and in addition to the soil sampling access agreement

previously obtained through the UVSP.

Specific cleanup details will be developed on a property-by-property basis. Individual property

cleanup work plans will be prepared for each property to identify the soil removal areas, excavation

depth, and revegetation requirements. Cleanup work plans will be reviewed with the property owner

and tenant, if applicable, during a pre-excavation property inspection. The inspection will be

attended by the property owner (and/or tenant if he/she requests to be present and is available) and

the CPC.

The cleanup work plan will document all pertinent details of the cleanup construction activities,

including items to be relocated for access, excavation areas, specific areas or landscaping that the

owner or their representative requests not to be excavated or removed, landscaping that will be

removed and replaced, and plants that the owner requests to be replanted.

After the inspection, the property owner will be asked to acknowledge the details of the cleanup by

signing the property cleanup work plan.

3.1.2 Town of Clarkdale Permits

Excavation activities located within the Town of Clarkdale municipal limits will meet the

requirements of the Town Code of the Town of Clarkdale, Arizona, specifically Chapter 7 pertaining

to grading and rights-of-way permits and any other relevant or applicable legal requirements of the

Town of Clarkdale. For excavations, a grading permit (required) and rights-of-way permit, if

necessary, will be obtained from the Town of Clarkdale by the CPC prior to commencing cleanup

activities at a particular property.

3.1.3 Pre-Excavation Area Preparation

The CPC will notify the property owner and tenant of the intended start date at least seven calendar

days prior to the start of construction at a particular property. Implementation may proceed at a

given property with shorter notice if the property owner or tenant does not object.

Prior to beginning work on a particular property, the CC will mark the lateral excavation limits and

set up construction tape or fencing to limit unauthorized access. Excavation will be performed in the

accessible portions of the use areas designated for cleanup. Use areas eligible for remediation may

include grass-covered and bare areas; gardens and flowerbeds (unless the owner requests

otherwise), and unpaved driveways and parking areas. Examples of use areas not eligible for

remediation include those covered by grouted brick or pavement surfaces (such as concrete pads,

patios, paths, and driveways) where permanent structures are present (such as houses, garages,

and sheds), areas covered by large landscaping items (such as retaining walls, water features,

etc.), and setbacks from structures, large landscaping items, and buried utilities. Appropriate

precautions will also be taken to avoid contact with overhead power lines during soil remediation


activities by observing proper work activity setbacks, which could also result in some portions of

impacted use areas not being remediated.

In addition, the CPC will survey (via photographs and/or video) each property to establish

pre-cleanup conditions. The condition of buildings and other fixtures will also be documented,

including the integrity of structures and foundations immediately adjacent to the target excavation

areas.

Prior to initiation of cleanup construction activities, the CC will contact the local utility companies to

locate the underground electrical, water, sewer, gas, cable, and telephone lines. The owner and

tenant will also be asked to provide information on subsurface obstacles such as septic systems,

abandoned water lines, and wells. The utility companies will mark the boundary position of the

utilities on the ground following their normal convention. The CC will also locate the layout of utilities

within the use areas to be excavated. In use areas requiring soil excavation, the CC will confirm

locations of subsurface obstacles, including gas lines, by hand digging to trace the orientation of the

obstacle and will mark it with spray paint.

The property owner or tenant will be required to relocate recreational vehicles, lawn furniture, spare

lumber/building supplies, boats, vehicles or other similar items to a location where they will not

hinder cleanup activities. Additionally, the property owner or tenant will be required to relocate pets,

poultry and livestock to a location where they will not hinder cleanup activities. Assistance will be

provided if the property owner is not capable of performing these activities. If off-site

storage/boarding is required, FMC will make arrangements and pay for the storage/boarding. The

CPC will also request that the property owner or tenant remove and store inside their buildings all

yard ornaments, personal possessions, and keepsakes requiring special care. The items to be

relocated by the property owner will be noted on the cleanup work plan as well as any concerns or

special requests that the property owner or tenant may have in removing surface obstacles or in

otherwise preparing their property for cleanup activities.

If practicable, the CC will temporarily relocate woodpiles, walkway stepping-stones, and other

miscellaneous small landscape articles on the property; large obstructions such as fences and

gates may be removed, if necessary, by the CC to allow for equipment and work crew access.

Removed landscape articles and obstructions will be stored on the property and will be replaced by

the CC following completion of cleanup activities.

3.1.4 Excavation Activities

Excavations may be required in a front use area, back use area, separate side use area or

combination thereof. Side use areas that are less than 15 feet wide, but greater than 5 feet wide,

will have been sampled as part of either the front yard or back yard as described in the SAP (GHD,

2015a). In this case, the side use area will be excavated only if the front yard or back use area that

it was a part of is excavated. In the event that a side use area is less than 5 feet wide (and

therefore, not sampled) and accessible, it will be excavated if either the front or back yard requires

cleanup. In this case, the entire accessible portion of the side use area will be excavated.

For purposes of the cleanup activities, a use area will be defined as extending to the edge of the

adjoining street or alley; property line or any drainage ditch/wash. Generally a curb or, in the

absence of a curb, the edge of the pavement will define the edge of the alley or street.


If a use area is larger than 3,600 square feet, it will have already been subdivided into grids for the

purpose of property sampling. In this case, the designated excavation area will be the grid area

represented by the composite sample that has soil concentrations above the ADEQ approved

cleanup levels for one or more TCs. For areas designated for excavation by discrete sample results,

the horizontal limits of excavation will be defined by discrete sample locations with concentrations

less than the cleanup levels or by significant physical obstructions such as foundations, streets or

sidewalks.

The depth of excavation will be determined by sampling in multiple intervals as specified in the SAP

and will generally extend to the top of the sample interval where the soil concentrations for arsenic,

copper, lead, tin, zinc and boron are below the cleanup levels. In the event only a 0-3 inch interval

exceeds any TC, the excavation will be extended to the 0-6 inch interval as a practical excavation

technique. FMC will attempt to remove all soils with elevated TCs; however, an excavation may be

terminated at a shallower depth if full removal is not practical (e.g., encountering roots of mature

trees or bedrock) or the CC cannot safely excavate the soil. In such a case, the removal will extend

to the deepest depth practicable and the excavation backfilled as described in Section 3.1.10.

The CC will remove soil using a variety of mechanized equipment and hand tools. The primary

equipment used will consist of skid steer loaders (e.g., bobcats), small excavators or other similar

equipment. Soil will be removed to the specified depth, taking care to hand excavate next to

buildings, sidewalks, fences, and other structures as necessary to achieve an objective of

maximizing the extent of soil removal. The potential for damage to structures and utilities will be

considered on a case-by-case basis in determining the extent of the excavation. Any nominal

amounts of soil that may be left in place as a result of these considerations will not affect the

achievement of the primary objective of the cleanup, which is to excavate and replace soils within a

designated area of the property, to the extent necessary, to ensure that the post-cleanup average

metals concentrations no longer exceed the cleanup levels.

The nominal setbacks that will be considered as guidance in weighing the considerations described

above are as follows:

• Horizontal distance of 12 to 18 inches from permanent structures (house, garage, outbuildings,

etc.).

• Horizontal distance of 6 to 12 inches from other improvements (sidewalks, paved areas, etc.).

• Within the drip line of shrubs.

• Within the root line of trees.

• Horizontal distance of 24 inches from active underground utilities when mechanized equipment

is used.

• Horizontal distance of 6 inches from active underground utilities when hand tools are used.

• Limit depth of removal to 12 inches within two feet from other permanent appurtenances or

improvements (e.g., power poles, light poles).

• Horizontal distance of 6 to 12 inches around large stationary objects (e.g., sheds, animal

shelters, inoperable automobiles).


• Appropriate distance from structures with basements so as not to impact basement walls (to be

determined on a case-by-case basis).

• Horizontal distance of 6 inches from fences that are not removed for access.

• Horizontal distance of 6 to 12 inches from the property line.

In addition to a setback, soil excavation will be sloped at a 45 degree angle away from the edges of

rock structures, retaining walls, weak concrete foundations or other supporting structures to prevent

loss of support and potential weakening of these features. Utility lines (including water, electric,

sewer, gas, cable, and telephone) damaged by cleanup activities will be reinstalled to current

building code requirements by the CC as soon as practicable after the damage occurs. Utility

companies shall be notified of any damage to their infrastructure and a Town of Clarkdale permit

shall be required for repair to water, gas and electric lines and infrastructure. Appropriate measures

will be taken to provide for the property owner’s needs while repair is being performed.

Soil excavation may not be conducted in or near areas with deteriorating or unstable retaining walls

which present potentially significant safety or property damage concerns. FMC will consider

returning to remediate the areas if the property owner addresses the safety concerns (i.e. repairs or

stabilizes the wall).

Excavation by hand will be performed, as necessary, to mitigate damage to structures (e.g.,

houses, garages, sheds, paved driveways, and sidewalks) and vegetation (e.g., trees, hedges, and

large shrubs). The CC will routinely inspect structures during excavation operations and will take

reasonable and appropriate corrective action if damage occurs.

Excavation beyond the setback specified above for trees and shrubs will extend to the full

designated depth for that area. Excavation within the setback of trees and shrubs will be limited to

the removal of existing grass and the immediately underlying soils (3 to 6 inches) to minimize

potential damage to the root structure.

If required for access, fences may be removed, salvaged, and replaced upon completion of the

backfilling by the CC. Removal or location of existing fences shall be noted on the original Town of

Clarkdale grading permit submission if possible or submitted as an addendum to the original permit

to ensure accuracy of the permanent property file records at the Town of Clarkdale. Damaged

fences or fences that cannot be reinstalled following backfilling will be repaired or replaced with

fencing that is equivalent to the existing fence.

The exteriors of structures and buildings will be inspected for evidence of deformation or changes in

condition attributable to the cleanup activities based on a review of the pre-excavation

photographs/video documentation. The CPC will contact the property owner when conditions are

discovered that warrant such notifications.

The CC and CPC will jointly perform the field measurements specified in the QAPP (GHD, 2015b)

to confirm that the required excavation extent and depth have been achieved. Once the CPC has

verified that an excavation meets the project requirements, the area will be approved for backfilling.

3.1.5 Loading Excavated Materials

Loading of the material excavated from individual properties for transport to the Soil Repository (see

Figure 2) will be performed in a manner that prevents spillage or spreading of the material. A


protective temporary covering, such as polyethylene sheeting (6-mil Visqueen or equivalent) or a

CPC-approved geotextile, will be used to protect clean areas situated between the hauling vehicle

and the excavation area from cross-contamination due to spillage.

Spilled soil will be isolated by traffic cones as necessary and will be picked up immediately to

minimize any subsequent tracking of materials or transport of materials beyond the work site or into

local storm drains.

Loading of trucks will be performed to avoid contact with overhead electrical lines and other utilities.

Dust control methods in compliance with relevant and applicable Town of Clarkdale regulations will

be maintained in accordance with the Fugitive Dust Control Plan (FDCP) presented in Appendix B.

After loading, trucks will be covered with an adequately secured tarp or other device and inspected

for loose/spilled material within the loading zone. Loose materials accumulated on the sides, tires,

wheels or dump gates of the trucks will be removed and placed within the truck. Spilled soils in the

vicinity of the loading area will be removed (using broom and shovel or other suitable means) and

placed in the truck. Then, the excavated soils will be transported to the Soil Repository (Section

3.2).

3.1.6 Noise Control

Normal working hours will begin no earlier than 7:00 a.m. and will generally extend no later than

7:00 p.m. All equipment shall be maintained in proper condition with exhaust controls to minimize

noise levels, and proper driving habits will be enforced. Residents will be provided with the UVSP

office telephone number to allow reporting of any noise complaints. If noise complaints are

received, the CPC will assess the issue and, if deemed necessary, require the CC to modify

equipment or operational procedures, to mitigate the noise. Article 10-1-11 of the Town of Clarkdale

Town Code shall apply to noise complaints submitted to the Town of Clarkdale.

3.1.7 Dust Control

Dust control requirements and personal monitoring procedures during cleanup activities are

described in the FDCP presented in Appendix B. Water application will be used as necessary to

reduce fugitive dust. Application rates will be regulated to control dust, yet not result in the

generation of mud that could be transported from work areas on haul trucks or other mobile

equipment or in the generation of runoff to adjacent properties, the adjacent roadway or storm

drains. Dust suppression equipment may consist of standard garden hoses and spray regulators,

misters or other equipment proposed by the CC and acceptable to the CPC. Per Section 7-11 of the

Town of Clarkdale Town Code, either a dust palliative or reclaimed water shall be used for the

alleviation or prevention of dust. Dust control methods consistent with the 2012 International

Building Code as adopted by the Town of Clarkdale and with Article 7-11 Excavation and Grading of

the Town Code shall be used, including the cessation of all activity during red flag warnings.

3.1.8 Access for Property Residents

During construction activities, access to the home will be provided to the residents at all times.

Appropriate measures will be taken to ensure that the resident will not have to walk through

exposed soil prior to entering their home. Sidewalks will be brushed or washed after each workday

to provide as clean an entryway as possible. If there is no sidewalk, a clean pathway will be


provided by laying down plywood or other means to prevent exposure and tracking of soils. All

residents (especially children) will be requested to stay away from the construction area, which will

be demarked with construction tape or fencing. Handicap access and special needs will be

addressed as needed. Should residents need to temporarily relocate during construction activities,

FMC will make and pay for those relocation expenses.

3.1.9 Decontamination Procedures

Heavy equipment and tools used in the cleanup process will be decontaminated prior to leaving the

work area. Decontamination will first involve a brush down of equipment in the work area to remove

visible accumulations of materials from the body of the equipment and tires. Limited quantities of

water may be used to remove residual visible soil following dry brushing; however, water use will be

minimized. If washing is necessary, equipment will be washed while on the premises and the wash

water mixed with the last load of excavated soil prior to transportation to the Soil Repository. In all

instances, which includes rainy days, the CC will work to minimize the migration of mud and water

to the street. Visible accumulations of soil, dust or debris that are attributable to construction

activities found on streets, rights-of-way, and access routes will be cleaned at a minimum of once

per day.

3.1.10 Backfill and Revegetation of Excavated Areas

After field measurements, collected in accordance with the QAPP (GHD, 2015b), confirm that the

design excavation depths have been achieved, the CPC will approve excavated areas for backfilling

with soil. Backfilling will follow excavation as soon as practicable in order to minimize the amount of

time excavated areas are left open. In general, the excavated areas will be backfilled to

pre-excavation grades. Minor modifications to the pre-excavation grades will be considered if

necessary to improve drainage provided that the property owner concurs and such improvement

can be accomplished without negatively affecting adjacent properties. In addition, all excavations

will require a grading permit approved by the Town of Clarkdale Community Development

Department.

Backfill materials will be imported from off-site sources approved by the CPC and either staged in

the Backfill Staging Area (BSA) prior to transport to a given property or direct-hauled from the

source to the property. Samples of the proposed backfill materials will be collected and analyzed to

verify that they meet the project requirements identified in the QAPP (GHD, 2015b) before the

material sources are approved. Following source approval, QA/QC samples will be collected and

analyzed on an ongoing basis to confirm that the backfill materials continue to meet the project

requirements. Backfill or replacement soil will be selected to ensure that it is a suitable replacement

for the excavated soil in characteristics, texture and structure and conforms to the approved Town

of Clarkdale grading permit. Details of the project QA/QC verification testing of the backfill materials

and review by ADEQ are described in the QAPP (GHD, 2015b).

Where access allows, dump trucks with backfill soil will drive onto the excavation areas and deposit

loads while driving slowly to spread the soil. Where access is limited, the trucks will dump loads at

an adjacent temporary stockpile from which the CC can transport the material. Written access will

be obtained from the owner of any adjoining private property to be used for equipment or material

staging during cleanup activities. If the use of the adjoining property entails only access, verbal

permission may be obtained.


Some handwork using wheelbarrows and shovels may be necessary to backfill areas with difficult

access. The backfill soil will be graded and shaped to the approximate original conditions.

Compaction of the backfill material will generally be performed by tracking of construction

equipment to prevent settlement. Material placed in driveways or alleyways will be compacted using

a plate compactor, roller, hand tamping or other suitable means.

The upper surface of the backfilled area will be refinished with restoration materials that are

comparable to the pre-existing conditions (i.e., sod, hydroseed-native grasses, landscape gravel,

gravel parking areas or gravel driveways, etc.). If sod installation or hydroseed application is

required, the vegetated area will be watered by the CC as necessary during the first 60 days after

installation to facilitate establishment of the vegetation. Property owners/tenants will be provided

with instructions for care of the sod and/or hydroseed after the 60-day period. Excavated gravel

driveways, parking areas, and other areas subject to vehicular traffic will be replaced with

compacted clean soil and a minimum of four inches of clean gravel top surfacing.

Landscaping that is removed or destroyed as part of the cleanup activities will be replaced with

comparable landscaping, if so requested by the owner. Landscaping includes, but is not limited to,

trees, sod, native grasses and wildflowers, shrubs, and plantings. As an alternative, in order to

reduce water usage, FMC is willing to consider installation of xeriscape landscaping in soil

replacement areas if the property owner so desires. Replaced landscaping will be replanted if it

does not survive within 60 days, provided that the property owner follows practices recommended

by the plant supplier. Plants that have been designated by the owner as requiring replanting will be

replanted; however, FMC cannot guarantee the survivability of replanted plants. The CC will also

water replaced or replanted landscaping within the first 60 days. Watering frequency and timing will

consider the time of year as well as the Town of Clarkdale’s Drought and Water Shortage

Preparedness Plan.

Finally, all materials such as fences that were moved by the CC to allow construction activities will

be restored to their original location and any incidental damage to buried sprinkler systems,

sidewalks, etc., will be repaired by the CC at that time.

3.1.11 Follow-Up Activities

Follow-up activities will be conducted by the CPC and the CC after cleanup construction activities

are complete at a given property to verify that the work has been performed appropriately.

3.1.11.1 Photo Documentation

Photographs and/or video will be used to document post-construction conditions of properties,

streets, and sidewalks. Photographs and videos will be taken by the CPC as soon as practicable

after completion of landscaping.

3.1.11.2 Repair Work

Cleanup activities will be conducted to minimize damage to permanent features. Any damaged

features, such as walkways or utilities, will be repaired or replaced upon discovery and

determination that the damage was caused by the cleanup construction activities. Structures such

as buildings, sidewalks, and fences that are damaged during property cleanup will be repaired. If

doubt exists as to whether damage was caused by the cleanup construction process, video and


photographic documentation taken prior to construction will be reviewed on a case-by-case basis.

The decision to repair disputed damage will be made by the FMC Project Manager.

3.1.11.3 Property Inspection

Once construction is completed and any necessary repairs are made, the CPC will inspect the

property with the property owner and the CC. At this inspection, the property cleanup form will be

finalized and the property owner and CPC will sign off that the work performed is consistent with the

signed property cleanup work plan. If the property owner fails to attend or declines to sign the

property cleanup form, the CPC will inspect the property. If the property has been cleaned up in a

manner that is consistent with the pre-construction inspection, the CPC will sign the property

cleanup form and it will be included in the residential property completion report.

3.1.11.4 Reporting

Once cleanup activities are complete at a specific property, a Property Cleanup Completion

Report (PCCR) will be prepared and submitted to the property owner. The PCCR will document the

location of the excavated areas and the depth of the excavations.

3.2 Soil Repository Area

The Soil Repository Area is located approximately one mile north of Clarkdale outside the Town of

Clarkdale limits on FMC property and within the Area of Contamination (AOC) of the former smelter

site as shown on Figures 1 and 2. GHD collected soil samples from the Soil Repository location,

documenting the extent of the AOC; Appendix C contains a summary of the soil sampling locations

and the laboratory analytical results.

The Soil Repository Area will cover approximately 25-acres and consist of the following

components:

Access road from Sycamore Canyon Road to the Soil Repository Area

An Equipment Storage Area

A zero-discharge Stormwater Containment Basin and other storm water control features, and

A Soil Repository, which will serve as the final resting place for soils generated from the UVSP

excavation activities.

The Soil Repository will consist of a lined and capped facility. The soil cap will support vegetation to

minimize seepage through the cover. The proposed design incorporates requirements outlined in

Part 2.5 of ADEQ’s Arizona Mining Guidance Manual, Best Available Demonstrated Control

Technology (BADCT) (ADEQ Pub. No. TB-04-01)) for tailing impoundments. In addition, the Soil

Repository Area is exempted from obtaining an Aquifer Protection Permit (APP) per Arizona

Revised Statute (ARS) 49-250.18c and ARS 49-701.01.12f. Standards, considerations, and

criteria for the design of the Soil Repository Area include the following:

Floodplains (BADCT Section 2.5.1.2): Material will not be placed within the 100-year floodplain.

Run-on / run-off control systems (BADCT Section 2.5.1.2): A run-on control channel will be

constructed along the eastern portion of the Soil Repository and sized to convey the 100-year,

24-hour storm event. The Stormwater Containment Basin will be sized to contain the estimated


water volume that results from the 100-year, 24-hour storm event during construction and

closure.

Site preparation (BADCT Section 2.5.2.3 and 2.5.2.4): Site preparation will include clearing the

area of vegetation, grubbing and grading as well as subgrade preparation, which will consist of,

at a minimum, twelve inches of 3/8 inch minus native materials. The soil surface will be

compacted, finished smooth and inspected prior to geosynthetics installation to remove

protruding particles, if present.

Bottom liner (BADCT Section 2.5.2.4): A 60-mil textured high-density polyethylene (HDPE)

geomembrane will be installed as the bottom liner over the prepared subgrade.

Drainage Layer and Collection System (BADCT Section 2.5.2.4): A geocomposite drainage

layer and gravity-fed drainpipe will convey percolation to the Stormwater Containment Basin

where the percolation will ultimately be evaporated into the atmosphere.

Slope Stability (BADCT Section 2.5.2.5): The Soil Repository design and construction will meet

the static and pseudo-static requirements of BADCT.

Cover material and thickness (BADCT Section 1.2.3 and 2.5.4): HELP modeling demonstrates

that average annual total percolation thru a 24-inch cover material is anticipated to be less than

five percent. This is mainly due to the arid climate conditions of the Site. Public Access

Control: A locked security fence will be installed to discourage unauthorized traffic and

uncontrolled dumping.

Groundwater Monitoring: Groundwater was not encountered during the geotechnical

investigation. Groundwater is anticipated to be approximately 50 to 80 feet below the ground

surface of the Soil Repository Area. Groundwater monitoring will not be performed due to the

efficiencies of the top cover and bottom liner.

Design, construction, operation and closure details for the Soil Repository Area are presented in Appendix D. Stormwater management at the Soil Repository Area is addressed in the ADEQ-

approved Stormwater Pollution Prevention Plan (SWPPP, AZCN69275 issued December 28,

2017)), which is compliant with ADEQ’s 2013 Construction General Permit (CGP) and approved by

ADEQ prior to the commencement of construction activities.

3.3 Soil Transportation

Excavated materials from cleanup properties will be transported to the Soil Repository and placed

directly in a lined containment area for long-term management. In addition, excavated material

temporarily stored at the Temporary Soil Staging Area (TSSA) will be removed and transported to

the lined Soil Repository. Backfill materials will be hauled to the excavated properties either directly

from the borrow source or the BSA.

Haul trucks will follow a direct route using major roadways and avoid neighborhood streets to the

extent practicable when traveling between the BSA and cleanup properties. The haul routes for

each property will be predetermined by the CC and/or the CPC. All truck drivers will be instructed as

to the preferred routes between the property, backfill source, and Soil Repository Area prior to

initiating hauling activities.


to the preferred routes between the property, backfill source, and Soil Repository Area prior to

initiating hauling activities.

The loads of all haul trucks, whether hauling excavated materials or backfill, will be covered with a

secured tarp or other device. Any materials spilled during transport will be cleaned up and removed

as soon as practicable.

Hauling operations will be performed pursuant to an approved traffic control plan approved by the

Town of Clarkdale, and will be conducted in such a manner as to minimize interference with local

traffic on city streets to the extent practicable. Flag persons and signage will be used as necessary

for public safety. At a minimum, warning signs such as "Construction Area" or "Workers Ahead" will

be placed on the streets where cleanup is being performed and haul trucks are being loaded.

"Trucks Entering" or "Trucks Turning" signs will be used at primary and secondary street

intersections as necessary. Any other signage required by local or state regulations, laws or

ordinances will also be used to provide for public safety.

Haul trucks and drivers for delivery of material to the Soil Repository will be required to comply with

all applicable federal, state, and local regulations. Drivers will be licensed to operate the equipment

under their control and will be subject to safety record checks. The material excavated from the

cleanup properties that is hauled to the Soil Repository will not involve the placement of hazardous

waste because all activities will be conducted within the AOC; therefore, transporters of this material

will not require licensing as hazardous waste transporters.

Haul trucks will pass all required safety, emission, and noise inspections. Trucks will be inspected

by the CC for leaks of fluids and fuel and will be checked for potential fire hazards associated with

loading equipment and haul trucks. Loaded trucks will not exceed applicable weight restrictions, and

the selected transport routes will be checked for weight-restricted bridges or other load limits prior to

initiating transport.

All truck drivers will be instructed that they must comply with all posted speed limits and other traffic

controls on public roads and that failure to comply will be a basis for removal from the project.

Prior to any materials being transported, truck drivers will be briefed by the CC regarding the

loading, inspection, and documentation requirements and any additional safety procedures

specified in the CC's Health and Safety Plan (HASP). All haul trucks will contain guidelines

regarding emergency procedures and motor vehicle accident report forms. Completed accident

report forms will be submitted to FMC’s Safety Personnel and the FMC Project Manager.

4. Construction Management Considerations

This section describes the overall construction management considerations associated with

implementing the cleanup, including specific sequences and inter-relationships of activities,

logistical requirements of various aspects of the work, and health and safety considerations.

4.1 Scheduling of Cleanup Properties

Prioritizing the cleanup of properties will be based on a three-tiered approach, generally consistent

with the United States Environmental Protection Agency (EPA) Superfund Lead-Contaminated


Residential Sites Handbook, OSWER 9285.7-50 (EPA, 2003). The application of these guidelines

for the soil cleanup activities takes into account the cleanup levels developed for the Study Area.

Tier I properties are residential properties with yard soil lead concentrations greater than 1,200

milligrams per kilogram (mg/kg) and a sensitive population: either a child less than seven years of

age or a pregnant woman residing or frequently at the property (i.e., at the property for four or more

days a week). Tier II properties are residential properties with yard soil lead concentrations between

the remediation level for lead (425 mg/kg) and 1,200 mg/kg and a sensitive population or lead soil

concentrations above 1,200 mg/kg and no sensitive population. Tier III properties are residential

properties with yard soil concentrations between 425 mg/kg and 1,200 mg/kg and no sensitive

population.

Relevant information on the residents will be solicited during the cleanup access agreement

process. This information will be combined with the results of the sampling to assign a Tier status to

each property where cleanup is required. In general, properties will be scheduled for cleanup on a

neighborhood-by-neighborhood basis considering the higher priority of Tier I and Tier II properties.

Non-residential properties will have lower priority than residential and recreational properties.

4.2 Construction Quality Assurance/Quality Control

Construction QA/QC testing and inspection procedures will be implemented to ensure proper

construction and compliance with the cleanup construction plans and specifications. Details of the

construction QA/QC programs are provided in the QAPP (GHD, 2015b).

4.3 Health and Safety

The CC will prepare a construction HASP that is protective of workers, the public, and the

environment. During all construction activities, the CC will have a designated Health and Safety

Coordinator on site. The Contractor’s Health and Safety Coordinator (CHSC) will have authority

over all CC personnel to enforce the HASP requirements.

5. Reporting

This section provides a summary of reporting procedures. Submittals to ADEQ will include one hard

copy original and one electronic version of all reports.

5.1 Cleanup Reporting

PCCRs will be prepared for each property where cleanup was performed. The PCCRs for

properties that have been cleaned up will be forwarded to the property owner.

5.2 Data Reporting

Within two weeks of commencement of the soil remediation activities, monthly reports will be

submitted to ADEQ. The monthly report will include base project statistics including the compiled

results of Weekly Documentation.


5.2.1 Weekly Documentation

The following documentation will be collected weekly.

• The week ending

• Total number of parcels in the Study Area

• Total number of parcels sampled and will include subdivisions such as:

– Sampled and no exceedances

– Sampled and contains exceedances

– Not sampled

• Percentage of parcels with completed sampling

• Total number of parcels to be sampled

• Total number of parcels with one or more use area impacted

• Percentage of parcels with one or more use area impacted

• Total number of parcels with no use area impacted

• Total number of parcels with remediation in progress or complete

• Percentage of total estimated parcels where remediation is in progress or complete

• Total number of parcels declining remediation

5.2.2 Monthly Reporting

The Monthly Progress Report will describe the significant developments during the preceding

period, including actions performed and problems encountered, the activities anticipated over the

next month, schedule of anticipated actions, and anticipated problems and planned resolution of

past or anticipated problems. Figures identifying the current status (i.e., sampled, remediation

pending, remediation complete, etc.) of properties within the Study Area will be included with the

Monthly Progress Report.

5.3 Final Report

After completion of all work, a final report summarizing the actions taken (soil sampling and cleanup

activities) will be submitted to ADEQ. The Town of Clarkdale and the public will be given the

opportunity to comment on the final report.

6. References

Arizona Department of Environmental Quality, 2009 Arizona Administrative Code, Title 18.

Environmental Quality, Chapter 7, Department of Environmental Quality Remedial Action,

January.

Arizona Department of Environmental Quality, Arizona Mining Guidance Manual Best Available

Demonstrated Control Technology, Aquifer Protection Program, Publication # TB 04-01.


GHD, 2015a, Sampling and Analysis Plan, United Verde Soil Program, Clarkdale, Arizona, October.

GHD, 2015b. Quality Assurance Project Plan, United Verde Soil Program, Clarkdale, Arizona, July.

International Society of Arboriculture. 2001. Avoiding Tree Damage during Construction.

Town of Clarkdale, Town Code of the Town of Clarkdale, Arizona, Chapter 7: Building. As revised

by Ordinance #371, Resolution 1509 on 11/10/15; effective 12/11/15.

United States Environmental Protection Agency (EPA). 2003. Superfund Lead-Contaminated Residential Sites Handbook. (OSWER Directive 9285.7-50).

GHD | Freeport Minerals Corporation - Remedial Action Work Plan | 11102656 (4)

Appendix A Title

Figures

Approximate Location ofSoil Repository Area

¬«89A

MAIN STS BROADWAY ST

N BRO

ADWA

Y

CEMENT PLANT RD

LUKE

LN

S ELE

VENT

H ST

Revis

ed By

File N

ame:

CLARKDALE, ARIZONA

Figure 1STUDY AREA LOCATION

5/10/2

018

Water

looRM

REMEDIAL ACTION WORK PLAN

LegendHighwayRoadStudy AreaTown of Clarkdale LimitsSoil Repository Area

Clarkdale

MesaPhoenix

§̈¦8

§̈¦40

§̈¦17A r i z o n a

1110

2656

(RAW

P)GI

S_WA

_001

Offic

e

ProgramUnited VerdeSoil

Storm Water Containment Basin

Fence

Soil RepositoryAccess Road

Equipment Storage Area

Decontamination Pad

TemporaryStockpile Area

(if Needed)

SYCAMORE CANYON RDRe

vised

ByFil

e Nam

e:

CLARKDALE, ARIZONA

Figure 2SOIL REPOSITORY AREA

7/9/20

18Wa

terloo

RM


LegendTown of Clarkdale LimitsSoil Repository AreaFenceAccess RoadDecontamination Pad

Equipment Storage AreaSoil RepositoryStorm Water Containment BasinTemporary Stockpile Area (ifNeeded)

TOWN OF CLARKDALE

1110

2656

(RAW

P)GI

S_WA

_002

Offic

e



Appendix A Title

Appendix A Draft Remedial Action Work Plan

Correspondence

1

Kienholz, James

From: Voss, Alicia <[email protected]>Sent: Thursday, October 20, 2016 9:56 AMTo: Kienholz, James; Mueller, StacySubject: FW: Remedial Action Work Plan for the United Verde Soil Program VRP Site, VRP Site

Code 512101-00

fyi

Alicia C. VossFreeport Minerals Company333 N Central AvenuePhoenix, AZ 85004602-366-8049 (o)602-316-5467

From: Geneva Saint-Amour [mailto:[email protected]]Sent: Thursday, October 20, 2016 8:39 AMTo: Voss, Alicia <[email protected]>; [email protected]; [email protected]; [email protected]: Remedial Action Work Plan for the United Verde Soil Program VRP Site, VRP Site Code 512101-00

Thank you for the opportunity to provide comment on this document. I reviewed the plan using the portal ofthe Town of Clarkdale and chose to copy Town officials. Below are my comments for all parties. Please feelfree to contact me if you have questions regarding my input.Thank you,Geneva Saint-Amour

Page 13- Scheduling of cleanup:Tier 1, 2 and 3 all reference the cleanup plan for properties with lead. No reference is made to the othermaterials being tested for. So no plan is stated for properties with arsenic et al? That seemed to be theprevalent toxicity in the target zone.

Page 6- SetbacksWithin the root line of a tree is a setback? The number of old-growth mesquites on and near my propertyhave a network of root lines that is quite extensive! That may preclude any earth removal in the areas of highconcentration of arsenic (as per the document mailed to me after sampling) Yet, the area under those trees isalso the most undisturbed parts of my property- and therefor where the arsenic has settled and laid on thesoil for all these years.

Backfill soil-I am unable to find a diagram or description of where the replacement soil (backfill) will be coming from. I cansee (page 9) that it will be tested and also where it will be stored. But there is no information as to its origin.

Location of soil repository-

2

This area seems to be very near the Verde River and Pecks Lake area. Both of which are critical to theunderground water source for residents in this area. The plan indicates that the soil will be tested there andthen determinations will be made….. but it never says what happens after that. Where does the soil go thatdoes NOT meet the analysis discussed at the bottom of page 11?

I am impressed with the detail to matters such as dust control, mud management, replanting, etc. It is clearthat this agency is familiar with projects such as this and has covered the common issues with this plan. Myconcerns are not really with the integrity of the agency or the work plan, but rather with the longer termeffects of the materials that are in our soil and therefor our water.

_____________________This e-mail has been scanned for viruses

November 2, 2016 Freeport Minerals Corporation Attention: Alicia Voss 333 North Central Ave. Phoenix, AZ 85004 Dear Ms. Voss, This letter addresses the National Park Service’s (NPS) concerns with the recently released draft

Remedial Action Work Plan (RAWP) for the United Verde Soil Program VRP Site, VRP Site Code

512101-00. We understand that the plan was submitted in accordance with the A.R.S § 49-175 and

specifically addresses the removal of contaminated soil from residential, non-residential, and publicly-

owned properties in Clarkdale, Arizona. We do not believe the plan adequately addresses all of the

potential environmental impacts of transporting, treating, and storing contaminated soil. The dumping and

storage of soil on lands currently owned and managed by the Freeport Minerals Corporation (FMC) is

particularly concerning as the proposed Excavated Soil Staging Area (ESSA) and Soil Repository are

within a few hundred feet of the Tavasci Marsh. Tavasci Marsh is part of Tuzigoot National Monument

(TUZI) and is listed as an Important Bird Area (IBA) and is habitat for many unique and sensitive species

of plants, animals, fish, amphibians, and reptiles including the threatened Northern Mexican gartersnake

(Thamnophis eques megalops).

As you know, TUZI has a long history of interaction with the United Verde Copper Company (UVCC)

and its successors. In fact, it was the UVCC that eventually ceded the land to create TUZI. Despite our

long relationship, the environmental consequences of mining and copper production have often been at

odds with the NPS mission goals. For example, dust storms containing mine tailings often interfered with

visitor enjoyment until they were capped and mitigated in 2006. So, while we certainly understand that

the remediation of contaminated soil in Clarkdale will help to protect community health, we also believe

IN REPLY REFER TO:

United States Department of the Interior

NATIONAL PARK SERVICE

Montezuma Castle and Tuzigoot National Monuments

527 S. Main St.

PO Box 219

Camp Verde, AZ 86322

that there are many potential environmental impacts that are not adequately considered in the draft

RAWP.

The RAWP mentions the need for grading and right-of-way permits issued by the Town of Clarkdale as

well as “adherence to permit standards” and consistency with “applicable federal, state, and local

requirements”.1 Will FMC apply for other permits associated with the removal and transport of

contaminated soil? Similarly, are there other documents or plans which analyze the potential

environmental impacts of the proposed transportation and long-term storage of contaminated soil in more

detail? In lieu of these documents, we have the following comments and questions.

The RAWP identifies a protocol for soil transportation that states “trucks will follow a direct route using

major roadways and avoid neighborhood streets to the extent practicable…truck drivers will be instructed

as to the preferred routes between the property, backfill source, and ESSA prior to initiating hauling

activities”.2 How many trucks will be operating in the area each day? Where is the backfill source? Will

FMC be responsible for damage to the road caused by truck traffic?

Although the RAWP addresses concerns with traffic-flow in residential neighborhoods, it does not

discuss the potential impacts caused by dump trucks on Tuzigoot Road, which is owned by the NPS.

Tuzigoot Road is a major access route to the Verde River as well as an access route to pedestrian trails on

NPS, Arizona State Park, and Forest Service lands. Has FMC considered how increased traffic on

Tuzigoot Road will impact recreational activities, Arizona State park and NPS operations, visitor

enjoyment, and the local economy?

The RAWP also states that “Any materials spilled during transport will be cleaned up and removed as

soon as practicable”.3 To reach the ESSA, trucks must cross over the Verde River via the Tuzigoot

Bridge. Does FMC have a more detailed contingency plan for spills that could occur in or around the

Verde River?

TUZI contains ancestral Native American sites and historic buildings listed on or eligible for the National

Register of Historic Places. These important places interpret human occupation and land use in the Verde

1 GHD, 2016, Draft Remedial Action Work Plan Voluntary Remediation Program, submitted to Freeport Minerals Corporation, Report No 4. Appendix D, pp.1. 2 Ibid. pp.12 3 Ibid. pp.12

Valley and represent the enduring cultures and histories of living Native American people. Depending on

the expected truck and equipment traffic on Tuzigoot Road, FMC operations may have short and/or long-

term visual and auditory impacts to these properties. Similarly, the use of trucks and heavy equipment

will also have negative impacts to visitor experience in and around TUZI. More information on the

number of trucks and the expected duration of the project would be helpful for assessing and

understanding these impacts in more detail.

Appendix A: Dust Control Measures, proposes several techniques to minimize fugitive dust generation

from proposed excavation and treatment activities. For activities on FMC land, Peck’s Lake is identified

as a primary water source for controlling fugitive dust. Water removal has the potential to disturb lake

sediments, which reportedly contain metal contaminants.4 Project activities have the potential to disturb

these sediments, which could then be flushed into Tavasci Marsh. Although the RAWP describes water

quality testing for dust control using Peck’s Lake water, how will FMC avoid disturbing lake sediments?

Appendix B: Excavated Soil Staging Area Operations Plan identifies a location and techniques for

storing, testing, and treating contaminated soils. TUZI is particularly concerned with the proposed

location for these activities because it is within a few hundred feet of the Tavasci Marsh, an important

component of the Verde River system. This area is also subject to seasonal flooding, particularly during

the Summer Monsoon. The development of the ESSA, as defined in the RAWP includes the construction

of a berm and the creation of concrete pads and a work area, in part, to control flooding, erosion, and the

transport of contaminated soil into the marsh. Has FMC considered the potential environmental impacts

of large-scale ground disturbance in and around the Tavasci Marsh?

We understand that the use of Toxicity Characteristic Leaching Procedure (TCLP) and Synthetic

Precipitation Leaching Procedure (SPLP) analysis is needed to characterize soils and determine final

storage locations for contaminated soils. It is unclear what long-term measures will be taken to manage

soil with testing results below the regulatory thresholds identified in the RAWP. We also understand that

decommissioning the ESSA will follow extensive soil testing. Does FMC have baseline data on arsenic,

copper, lead, and other heavy metals that may already be present in soil from this area? If so, how do

these levels compare with the regulatory thresholds identified in the RAWP?

4 Ecology and Environment, Inc., 1994, Expanded site inspection summary report (analysis of ESI results) Phelps

Dodge Verde Mine, submitted to U.S. Environmental Protection Agency, EPA ID# AZD983475773.

Soil removed from Clarkdale contains seeds of invasive plant species including but not limited to tree of

heaven (Ailanthus altissima), periwinkle (Vinca major), and Russian thistle (Salsola tragus). The

transportation and storage of soils containing invasive seeds will spread these plants into new areas

around Tavasci Marsh. The close proximity of the ESSA to the TUZI boundary would mean that the

burden to control these invasive plants, as they spread into NPS land, would become the responsibility of

the NPS. Does FMC have an invasive plant management strategy for preventing the spread of invasive

plants in the ESSA? If so, is a copy of this strategy available for NPS review?

Appendix C: Soil Repository Operations Plan addresses the long-term operation and maintenance of the

ESSA and Soil Repository. This includes a proposed annual monitoring and reporting period of ten years.

Will copies of these annual reports be provided to the general public and the NPS? What happens after the

ten year period? Appendix C identifies monitoring following unplanned events such as fires, floods,

heavy rains, and seismic events. If contaminants linked to historic smelter operations or the proposed soil

remediation program are discovered in Tavasci Marsh, will FMC take responsibility for coordinating and

implementing clean-up efforts on NPS land?

Appendix C identifies a monitoring program following storm water discharge events. Appendix C states

that storm water discharge will be “infrequent”. 5 Does FMC have long-term data that indicates the

infrequent nature of discharge events? Similarly, the plan states that, “the receiving stream will be

sampled up-gradient and down-gradient of the discharge”.6 Considering the proposed ESSA and Soil

Repository location, it is unclear what this sentence refers to. Presumably, “the stream” refers to Tavasci

Marsh. Will FMC contact NPS in the event that sampling is required?

It is also unclear whether the proposed sampling targets water, sediment, or soil. How will specific

sampling locations be chosen? If soil sampling occurs, how deep will samples be taken? A recent USGS

study7 found copper, arsenic, and other heavy metals within marsh sediments. If FMC proposes to sample

soil, how will new contamination be distinguished from existing heavy metals? Will this information be

shared with NPS and the public?

5 GHD, 2016, Draft Remedial Action Work Plan Voluntary Remediation Program, submitted to Freeport Minerals Corporation, Report No 4. Appendix C, pp.3. 6 Ibid. 7 Beisner, Kimberly R., Nicholas V. Paretti, Anne M.D. Brasher, Christopher C. Fuller, and Matthew P. Miller. 2014, Assessment of Metal and Trace Element Contamination in Water, Sediment, Plants, Macroinvertebrates, and

Fish in Tavasci Marsh, Tuzigoot National Monument, Arizona: U.S. Geological Survey Scientific Investigations Report 2014-5069.

NPS technical staff are continuing their review of the proposed plan and may have additional comments

and questions. While we appreciate the opportunity to review the RAWP, it is regrettable that the NPS

was not consulted regarding the development of the plan. We would appreciate the opportunity to discuss

our concerns with you in more detail and hope to work with FMC in the development of this and future

plans. If you have any questions or concerns, please contact me at [email protected] or (928)

567-5276 ext.223.

Sincerely,

Dorothy FireCloud

Superintendent

xc: John Patricki, ADEQ Doug Von Gausig, Town of Clarkdale

mailto:[email protected]

November 14, 2016

Town of Clarkdale P.O. Box 308 Clarkdale, AZ 86324 (928) 639-2400 phone (928) 639-2409 fax

Arizona Department of Environmental Quality Voluntary Remediation Program Attention: John Patricki 1110 W. Washington Street Phoenix, AZ 85007

RE: United Verde Soil Program (UVSP) - Remedial Action Work Plan (RA WP) Comments

Dear Mr. Patricki:

The Town of Clarkdale appreciates the opportunity to review and comment on the RA WP for Freeport Minerals Corporation's (FMC) soil remediation project being performed in Clarkdale. The Clarkdale Town Council has approved the submission of this letter and the attached comments on behalf of the Town of Clarkdale.

While a number of our comments simply seek to provide clarity and accuracy to certain statements within the document, others focus on the following larger issues that we consider substantive flaws in the RA WP, including:

• The Town of Clarkdale has concerns about the proposed location for the Excavated Soil Staging Area (ESSA) and the Soil Repository. Both lie on property that is currently zoned for residential use by Yavapai County, and both areas are within 100 feet of property within the Town of Clarkdale which has a zoning entitlement for Verde Valley Ranch, a proposed mixed-use development with 900 residential units.

• Both the ESSA and the Soil Repository are also immediately adjacent to Tavasci Marsh, which is a component of the Verde River system, a part of Tuzigoot National Monument and habitat for many unique and sensitive species. An Aquifer Protection Permit (APP) must be obtained to own or operate a facility that discharges a pollutant either directly to an aquifer, to the land surface, or the vadose zone in such a manner that there is a reasonable probability that the pollutant will reach an aquifer. Due to proximity to Tavasci Marsh, groundwater is expected to be shallow, possibly within a few feet of the bottom of the currently existing lined "pond" that was designed and constructed in the past, and never utilized, as an effluent holding facility. It is reasonably probable that metals or soil containing elevated concentrations of metals will impact the shallow aquifer, Tavasci Marsh, and Verde River. That said, Freeport must demonstrate that using the existing lined retention pond to contain impacted soil will be compliant with the APP program and be the most appropriate Best Available Demonstrated Control Technology (BADCT) as described in this RA WP.

Mr. John Patricki, ADEQ Voluntary Remediation Program November 14, 2016 Page2

• The RA WP lacks any reference to the replacement soil for the project. At a minimum, the plan should address the location and source for replacement soil for the project, the sampling and analysis protocol that will be used for the replacement soil, any transportation impacts relating to the replacement soil, and any permitting issues that may arise due to the location and process for excavating replacement soil. Backfill or replacement soil should be selected to ensure that it is a suitable replacement for the removed native soil in characteristics, texture and structure.

• Property owners who participate and have their properties remediated should be offered the option of having the interior of homes cleaned after the remediation process in the event that dust may have gotten into the house during the remediation process. (Note: This addition aligns with a statement by a FMC representative at the May 19, 2015 Clarkdale public meeting.)

• Section 3 .4 asserts that "The material excavated from the cleanup properties that is hauled to the ESSA will not be considered to be hazardous waste pursuant to the applicable regulations of the Resource Conservation and Recovery Act (RCRA) because it remains within the area of concern, therefore transporters of this material will not require licensing as hazardous waste transporters." Freeport needs to better explain how the ESSA and Soil Repository can be considered the same "area of concern" as each individual property in the designated Project Area within the Town.

• The RA WP lacks consistency with statements made by Freeport representatives at public meetings in Clarkdale, and with responses to concerns previously brought forward by the Town during review of the Sampling and Analysis Plan for the UVSP.

• The RA WP lacks specifics for planning for increased commercial traffic and other impacts on Tuzigoot Road and/or Sycamore Canyon Road. Tuzigoot Road is owned and maintained by the National Park Service, and is often used by pedestrians who recreate in the area.

• Freeport needs to explicitly say in this RA WP that Freeport will be the generator of any and all solid and hazardous wastes associated with the United Verde Soil Program.

• There is no reference to coordination with Yavapai County on permitting requirements that may be necessary due to the location of the proposed ESSA and the Soil Repository within residentially zoned property located in Yavapai County.

Thank you again for the opportunity to comment. We trust that the Town ofClarkdale's comments, along with those of other agencies, citizens and stakeholders in the Clarkdale-area will be given due consideration, and result in amendments to the RA WP to adequately address our concerns. Please do not hesitate to contact me if you have any questions.

Sip/7 ~ Town Manager

c: Alicia Voss, Freeport Minerals, UVSP Project Manager Clarkdale Town Council

Enclosure

Town of Clarkdale Comments on Remedial Action Work Plan for the United Verde Soil Program

November 14, 2016

The Town of Clarkdale has completed a review of the draft Remedial Action Work and have the following comments and concerns regarding the content of this document. Italicized text indicates text to be added, strikethrough text indicates text to be deleted.

1. Introduction:

Third paragraph/first sentence should be rewritten for accuracy. Both ADEQ and the Town of Clarkdale have raised question in the past as to the reason that the initial Study Area was selected and how that Study Area will be expanded in the future. We recommend the following amendment to improve the accuracy of the statement:

'The Study Area, exclusive of the origi,nal smelter site, includes mast-some properties likely to have been affected by ...

1.1 First paragraph- The objective of the UVSP ... within iadividaal ...

Comment: The Town requests clarification of Table 1.1 as to which Cleanup Level will apply to Town Parks.

2. Cleanup Activities

Comment: The RA WP does not include any details relating to the replacement soil that will be used for this project.

3.1.1 Property Access

Third paragraph/last sentence - property owner or their representative

3.1.2 Town of Clarkdale Permits

First paragraph/First sentence: ... to grading and rights-of-way permits and any other legal requirement of the Town of Clarkdale. Second sentence: excavations greater thaTJ: or eqaal to 50 el:lbie feet, a grading permit and rights-of-way permit, ifaeeessary as required, will be ...

Comment: Article 7-11 Excavation and Grading of the Town of Clarkdale Town Code as amended by Ordinance #371 requires a permit for ALL projects involving cut and fill of materials. This requirement is not based on the quantity of cut and fill.

3.1.3 Pre-Excavation Area Preparation

Second paragraph/third sentence - remediation may .... Flowerbeds (unless the owner requests otherwise); and other landscaped treatments and ...

Fifth paragraph/second sentence - delete the word physically.

Comment: Language should be added to this paragraph addressing the process for relocating/boarding pets, poultry and livestock.

1


November 14, 2016

Language should be added that CPC will arrange and pay for off-site storage if required as previously committed to by FMI representatives.

3.1.4 Excavation Activities

Fourth paragraph/second sentence states that excavations will be performed to a maximum depth of two feet.

Comments: This section is inconsistent with statements made during a public meeting in Clarkdale on May 19, 2015, where Freeport's Project Manager Alicia Voss said 'they may go deeper than 2feet depending on the test results found at the 2 feet depth ... '.

Terminating excavations at a maximum depth of two feet without collecting and analyzing soil at the base of each excavation is unacceptable, not typically allowed by any regulatory agency or State or Federal regulation, and is not standard practice if impacts in soil exceed a certain cleanup concentration; in this case, the "Residential Cleanup Level by Land Use" (CL) for each "Target Constituent" (TC). If samples collected and analyzed from "Interval D" indicate that any TC concentration exceeds a CL then further sampling must be completed at and below 24 inches to properly and responsibly determine if impacts reside deeper than this RA WP contemplates. This data would then be used on a case-by-case basis to determine if that soil should be removed to further minimize human contact in the future should the property owner make improvements to their property that contacts soil at that depth. That said, Freeport has an obligation to inform each property owner if soil residing at or below 24 inches is impacted above a CL for any TC so that the property owner can be involved with how this matter is resolved.

Additionally, Freeport should be obligated to add a declaration of environmental use restriction (DEUR) to each property where remediation is completed and impacts are left in place at or below 24 inches.

Seventh Paragraph - Add the following language: Utility companies shall be notified of any damage to their infrastructure and a Town of Clarkdale permit shall be required for repair to water, gas and electric lines and infrastructure.

Eleventh Paragraph-Add the following language: Removal or location of existingfences shall be noted on the original Town of Clarkdale grading permit submission if possible, or submitted as an addendum to the original permit to assure accuracy of the permanent property file records at the Town of Clarkdale.

3.1.4 Excavation Activities (continued)

In Section 3 .1.4, Freeport says that properties will be sampled according to the Sampling and Analysis Plan (SAP) (GHD, 2015a). The Town is highly concerned that Freeport is not planning to sample the 3-6 inches interval and Freeport claims that "the 0-3 inch interval is used to best represent the surface soil that may have been impacted by air deposition from the former smelter. Furthermore, the 3-6 inch interval is not likely to have more air deposition impact than the 0-3 inch interval. As will be explained in the RA WP, if the 0-3 inch interval exceeds any TC, the 0-6 inch interval will be removed as a practical excavation technique and, and therefore, is addressed." The Town did not see that clarification in this RA WP as promised by Freeport and that should be included in the final RA WP.

Additionally, the Town agrees that the current approach to remove the 0-6 inches interval 'practically' address this concern. However, unless Freeport plans to collect a statistically significant number of samples from all intervals, including the 3-6 inches interval and analyze those samples for each TC, then this approach and Freeport's explanation is flawed. Freeport's explanation is flawed because the 3-6 inches interval can exceed the 0-3 inches interval TC concentrations because deposition from the smelter

2


November 14, 2016

stopped approximately 60 years ago. During the last 60 years, TCs have likely leached deeper, the soil at many if not all properties has been disturbed and impacts redistributed into the 3-6 inches interval, and intentional and natural soil accumulation at land surface of native soil not impacted by the smelter (the 0-3 inches interval) can likely be the interval with the lesser impacts. Unless Freeport plans to demonstrate with data rather than a potentially flawed theory, that "the 3-6 inch interval is not likely to have more air deposition impact that the 0-3 inch interval", then the 3-6 inches interval should be sampled and analyzed in the event the 0-3 or the 6-12 inches intervals demonstrate that CLs are not exceeded at 0-3 or the 6-12 inches intervals, and therefore no remediation potentially occurs.

The Town highly recommends that Freeport follow a more typical sampling and analysis approach implemented under Order and Consent by the United States Environmental Protection Agency (USEP A), Region 4, whereby the Responsible Parties (RPs) were obligated to follow the provisions of the agreed upon "Administrated Agreement and Order on Consent for Removal Action" relating to the Anniston Lead Site (AOC). Phelps Dodge Industries, Inc. (Freeport) was a "Respondent" in that matter.

In the Anniston Lead Site Quality Assurance Project Plan dated March 15, 2005, Section 4.0, Sampling Rationale, references used to prepare the sampling methods are:

o A Compendium of Superfund Field Operations Methods (EP N540/P-871001 o Samplers and Sampling Procedures for Hazardous Waste Streams (EPA-600/2-80-018) o Test Methods for Evaluating Sold Wastes-Physical/Chemical Methods (EPQ SW-846,

Third Edition, April 1998) o Superfund Lead-Contaminated Residential Sites Handbook (OSWER 9285.7-50, August

2003) o XRF SW 846 Draft Method 6200.

Section 4 goes on to say... "Confirmation sampling will consist of a screening XRF sampling/or lead and a composite laboratory analyzed sampling/or lead. XRF screening will be performed at the base of excavations to verity the complete removal of soils with lead concentrations above 400 ppm and to delineate areas, if any, that require additional excavation and removal. Composite soil samples will be collected from the base of excavations and sent to a laboratory for confirmation that the remaining soil meets the removal confirmation criteria of 400 ppm lead, as specified in the AOC " Section 4.1.1 of the QAPP further says that "After excavation is complete, and XRF screening has demonstrated that lead concentrations in subgrade soils are less than 400 ppm, a composite sample will be collected from the base of the excavation for laboratory analysis of total lead " That said, Freeport should revise this draft RA WP and simplify the approach by collecting and analyzing samples from each interval to determine the concentrations of each TC and remediate accordingly. Additionally, confinnation samples should be collected from the base of each excavation to demonstrate that subgrade soils are less than each CL for each TC. The City believes this approach will satisfy the concerns relating to not collecting and analyzing soil samples from the 3-6 inches interval. Alternatively, the City's concerns can be minimized if Freeport plans to collect a statistically significant number of samples from all intervals, including the 3-6 inches interval and analyze those samples for each TC to demonstrate the approximate concentrations, at depth in soil for each TC and prove that "the 0-3 inch interval is used to best represent the surface soil that may have been impacted by air deposition from the former smelter.

Why is Freeport not using an x-ray fluoresce analyzer to screen soil in the field to determine in real time the approximate concentrations of each TC in soil at each interval, including the base of each excavation?

3


November 14, 2016

3.1.5 Loading Excavated Materials

Third Paragraph/second sentence: Dust control methods in compliance with Town of Clarkdale regu,lations will be maintained ...

3.1.6 Noise Control

Add the following language: Article 10-1-11 of the Town of Clarkdale Town code shall apply to noise complaints submitted to the Town of Clarkdale, regardless of the CPC 's assessment.

3.1. 7 Dust Control

Comment: Per Section 7-11. Q of the Town of Clarkdale Town Code, either a dust palliative or reclaimed water shall be used for the alleviation or prevention of dust. Dust control methods consistent with the

2012 International Building Code as adopted by the Town of Clarkdale and with Article 7-11 Excavation and Grading of the Town Code shall be enforced including the cessation of all activity during active red flag warnings.

3.1.8 Access for Property Residents

Add the following language: Should residents need to relocate during the remediation, the CPC or FM! will work with those residents and will cover those expenses.

3.1.9 Decontamination Procedures

Add the following language: Property owners will be offered the option of having the interior of homes cleaned after the remediation process in the event that dust may have gotten into the house during the remediation process. (Note: This aligns with a statement by a FMI representative at the May 19, 2015 Clarkdale public meeting.)

Comment: This section should address the plan for rainy days.

3.1.10 Backfill and Revegetation of Excavated Area

First paragraph, last sentence: In addition, all excavations over 50 eaeie feet will require ...

Second paragraph/ Add the following language: Baclifill or replacement soil should be selected to ensure that it is a suitable replacement for the native soil in characteristics, texture and structure and conforms to the approved grading permit.

Sixth paragraph: Replace the word desert with xeriscape.

Comment: Scheduling for the watering of any landscape should coordinate with the Town of Clarkdale' s Drought and Water Shortage Preparedness Plan. In addition, consideration shall be given as to whether the time of year is appropriate for planting and replanting, given any watering restrictions in place at the time.

4

3.1.11.2 Repair Work


November 14, 2016

Comment: Is there an appeal method for property owners?

3.2 Excavated Soil Staging Area

Comments: Freeport needs to better explain its plan relating to activities contemplated at the Excavated Soil Staging Area (ESSA). This section says that the property (the ESSA and Soil Repository) is owned by Freeport and that "at its own discretion, elect to treat the weekly excavated stockpile as described in the Excavated Soil Staging Area Operations Plan (Appendix B) if there is a history of untreated weekly excavated stockpiles exceeding the TCLP and/or SPLP threshold concentrations". Freeport's concept of "area of concern" is too broad and not consistent with the Resource Conservation and Recovery Act (RCRA) or the National Contingency Plan (NCP) and cannot include commercial, public, residential properties and the ESSA and Soil Repository which are approximately 1.0 mile from the subject commercial, public and residential properties being remediated; in general, the entire Town, public land and land owned by Freeport cannot be considered an "area of concern". If Freeport desires to apply the "area of concern" concept allowed by RCRA, that "area of concern" must be limited to the subject and impacted properties being remediated, and the ESSA and Soil Repository not be included as part of the "area of concern". That said, treating "Characteristic Hazardous Waste" at the ESSA must be consistent with RCRA and a Treatment Storage and Disposal Part A and Part B permits must be obtained before these activities can be allowed.

Section 3 .2 does not describe how many samples will be collected per cubic yard of potentially "Characteristic Hazardous Waste" and how those samples will be handled to determine the impacts contained in the excavated soil removed from the subject properties. Appendix B does contain further information; however, Freeport should do a better job explaining the details associated with federal regulations relating to collecting representative samples, how Freeport is going to employ RCRA requirements, specifically "Test Methods for Evaluating Solid Waste: Physical/Chemical Methods, also known as SW-846, in order to be consistent with RCRA. Because the ESSA likely cannot be part of the overly broad "area of concern" currently being contemplated, Freeport needs to describe how these activities would be completed at each subject property, rather than the ESSA, in order to not violate RCRA and transport potentially "Characteristic Hazardous Wastes" on Town, County and Federally owned roads without proper permits. Further, Freeport needs to explain how and where "Characteristic Hazardous Wastes" will be disposed in a permitted Hazardous Waste landfill, and not treated at each subject property contained within the more reasonably sized "area of concern" because treatment at each property is not desirable nor practical.

What operations, maintenance, and monitoring activities will Freeport implement to ensure that this area is not disturbed, waste is not removed, waste is not blown and spread, waste is not eroded by surface water, and if and what type of groundwater monitoring will be implemented to ensure that a groundwater and/or surface water resource is not impacted in the future?

How will the excavated soil be profiled and managed if it fails either TCLP or the SPLP testing procedures?

The area for the stockpiled material is outside the jurisdiction of the Town of Clarkdale and under the authority of Yavapai County. The RA WP does not address any permit requirements from Yavapai County.

5


November 14, 2016

3.3 Final Excavated Soil Management

Comments: Section 3 .3 does not describe how the soil will be "profiled" and managed if that soil fails either the TCLP or the SPLP testing procedures. As stated above, Freeport's "area of concern" concept is not likely consistent with RCRA and excavated soil from each property must be properly characterized and "profiled" before non-hazardous soil is relocated to the ESSA or Soil Repository, or to a Hazardous Waste Landfill depending on the TCLP or the SPLP results. Additionally, discrete samples must be collected at the bottom of each excavation so that at a minimum property owners understand deeper soil conditions at their property to avoid being exposed to unacceptable soil impacts; or, these data should be used by Freeport to further excavate impacted soil below 24 inches should soil impacts exceed the Residential Cleanup Levels (CLs).

This section also needs to address what happens to water that accumulates in the lined pond. Additionally, ifthe lining in the pond is integral to the project, Freeport should demonstrate that the integrity of the liner is appropriate for the project. The liner was placed in the pond more than 10 years ago, has been exposed to the elements, and has had very little, if any, maintenance since that time.

3.4 Soil Transportation

Comments: The borrow soil site needs to be identified. Documentation needs to be included as to how many samples per cubic yard will be collected and analyzed to determine the borrow soil is from a suitable source. Freeport needs to describe how they are going employ US Environmental Protection Agency (USEP A) guidance, or specifically SW-846 to determine the appropriate numbers of samples will be collected, treated, and analyzed. In addition to analyzing borrow soil for arsenic, copper, lead, tin, zinc, and boron; Freeport needs to also analyze potential borrow soil for benzene, toluene, ethylbenzene, and xylenes (BTEX), and for volatile organic compounds (VOCs ).

All transportation shall conform with the approved traffic plan for the initial grading permit.

Section 3.4, 5th paragraph says "The material excavated from the cleanup properties that is hauled to the ESSA will not be considered to be hazardous waste pursuant to the applicable regulations of RCRA because it remains within the area of concern; therefore, transporters of the material will not require licensing as hazardous waste transporters." This Town disagrees with Freeport's concept of"area of concern". Freeport's concept is too broad and not likely consistent with RCRA or the NCP and cannot include commercial, public, residential properties and the ESSA and Soil Repository which are approximately 1 mile from the subject commercial, public and residential properties being remediated; in general, the entire Town, public land and land owned by Freeport cannot be considered an "area of concern". If excavated soil at each subject impacted property fails TCLP analyses, then Freeport needs to comply with RCRA in its entirety. Likewise, Freeport appears to assume it need not comply with handling and transportation requirements because of the CERCLA exemption described in § 121 ( e) of CERCLA, 42 USC 962l(e). Freeport needs to substantiate why it need not comply with these requirements. Even where it applies, this CERCLA permit exemption only applies to work completed onsite and requires substantive adherence to this Section and permit requirements. Additionally, Freeport needs to explicitly say in this RA WP that Freeport will be the generator of any and all solid and hazardous wastes. If Freeport desires to apply the "area of concern" concept allowed by RCRA, that "area of concern" must be limited to the subject and impacted properties being remediated, and the ESSA and Soil Repository not be included as part of the "area of concern". That said, treating "Characteristic Hazardous Waste" at the ESSA must be consistent with RCRA and a Treatment Storage and Disposal Part A and Part B permits must be obtained before these activities can be allowed. Freeport should describe in writing how their "area of concern" concept is allowable and consistent with Federal and State laws and regulations as they apply to this RA WP.

6


November 14, 2016

Eight Paragraph/last sentence - Police reports for any incident on public property shall be filed with the Town of Clarkdale Police Department.

4. Construction Management Considerations

4.1 Scheduling of Cleanup Properties

Comment: The regulatory reference is not appropriate for handling waste soil, profiling waste soil, transporting waste soil, accumulating waste soil, treating waste soil to remove "Hazardous Wastes" "Characteristics", or finally disposing waste soil to the land.

Comment: Recreational properties need to be referenced in the scheduling protocol.

5. Reporting

Comment: The Town of Clarkdale requests electronic version of all reports related to Town owned property, including but not limited to complete laboratory testing reports.

5.2.1 Weekly Documentation

Add Total number of parcels declining remediation

Comment: Will maps at the parcel level be included in this weekly documentation? Will the Town of Clarkdale receive copies of these weekly reports?

5.2.2 Monthly Reporting

Comment: The Monthly Progress Reports that have been delivered to ADEQ to date do not include the level of detail as described in the RA WP. Those submitted so far have not included the narrative descriptions relating to significant developments during the preceding period, including actions performed and problems encountered, the activities anticipated over the next month, schedule of anticipated actions, and anticipated problems and planned resolution of past or anticipated problems.

5.3 Final Report

Add the following: The Town of Clarkdale and the public will be provided the opportunity to comment on the Final Report.

6. References

Fifth bullet point add: as revised by Ordinance #371, Resolution 1509 on 11/10/15; Effective 12/11/15.

Appendix A Fugitive Dust Control Plan

1. Introduction: Second Paragraph/Second Sentence - add the Town of Clarkdale to the list of observations of dust.

3. References: add the following language to the second bullet point: as amended by Ordinance #371

7


November 14, 2016

Comment: The Town requests incorporating provisions for stationary dust sampling stations to be placed up- and downwind from the larger work areas to confirm dust control measures are adequate.

Appendix B Excavated Soil Staging Area Operations Plan

Comment: The Town of Clarkdale has concerns about the proposed location for the staging area. The area is immediately adjacent to property within the Town of Clarkdale which has a zoning entitlement for Verde Valley Ranch, a proposed mixed-use development with 900 residential units. The subject property is under the administration of Yavapai County and zoned for single-family development.

An Aquifer Protection Permit (APP) must be obtained to own or operate a facility that discharges a pollutant either directly to an aquifer, to the land surface, or the vadose zone in such a manner that there is a reasonable probability that the pollutant will reach an aquifer. The ESSA is within a few hundred feet of the Tavasci Marsh, a component of the Verde River system. As such, groundwater is expected to be shallow, possibly within a few feet of the bottom of the currently existing lined "pond" that was designed and constructed in the past for a different purpose. It is reasonably probable that metals or soil containing elevated concentrations of metals will impact the shallow aquifer, Tavasci Marsh, and Verde River. There are numerous requirements specified in the APP program, however, special attention should be paid to the following items: 1) Best Available Demonstrated Control Technology (BADCT, pronounced "bad cat"). Freeport must show that the best demonstrated control technology will be used by the facility. 2) Freeport must show that Aquifer Water Quality Standards (AWQS) will not be exceeded in the aquifer at the point of compliance as a result of discharge from the facility. If the level of a pollutant in the aquifer already exceeds the A WQS at the time of permit issuance, the aquifer must not be further degraded as a result of the discharge. 3) Freeport must show that they have the financial and technical capability to operate in accordance with the permit. In most cases, individual permits are issued for the operational life of the facility. That said, Freeport must demonstrate that using the existing lined retention pond to contain impacted soil will be compliant with the APP program and be the most appropriate BADCT as described in this RA WP.

Figure B-1

This figure shows the locations for the ESSA and the Soil Repository Locations. Has Freeport evaluated if there any jurisdictional waters of the United States regulated by the Clean Water Act or the Clean Water Rule? In addition, has Freeport evaluated the actions associated with this RA WP that may trigger any evaluation under the Nation Environmental Policy Act?

Section 2.1.2 Erosion Control

Erosion control measures should be maintained in perpetuity around the Soil Repository, not just around the ESSA during the duration of the Soil Program cleanup activities. This would likely be required by the APP program which Freeport should be required to implement as it relates to this RA WP.

Section 2.2.1 Movement of Material within the ESSA

6 inches of suitable aggregate placed on top of a geotextile fabric should be considered the minimum control to minimize tracking soil, dust, or mud onto public right-of-ways. Freeport should also be required to make provisions for street sweepers and exit grids if the minimum control fails to contain soil

8


November 14, 2016

within the ESSA. This would likely be required by the APP program which Freeport should be required to implement as it relates to this RA WP.

Section 2.2.2 Initial Material Segregation and Soil Characterization

Describes the numbers of grab samples to be collected from each stockpile and is reasonable as long as each pile is no greater than 1,000 cubic yards and each grab sample is collected from approximately equally spaced locations on and within the stockpile. Because potentially "Characteristic Hazardous Waste" should not be transported to the ESSA for sampling, profiling, and treatment because many provisions of RCRA could be violated, smaller soil stock piles should be created and managed at each individual property; therefore, limiting the size of each stockpile making the stockpile sampling plan reasonable.

2.2.3 Soil Management, Treatment and Storage

This section says "FMC understands that management of excavated soil within the ESSA will be on a temporary basis, and soil may only be managed at this location for a maximum of one year from the time the soil was first placed in the ESSA until the soils can be placed into the Soil Repository". As described above, no "Characteristically Hazardous Waste" should be transported to the ESSA unless the proper permits are in place. Additionally, Freeport should describe how it will comply with State law relating to handling and managing non-hazardous waste at this location.

2.2.5 ESSA Decommissioning

This section repeatedly references "site-specific cleanup levels ( CLs) for commercial land use". To our knowledge, there is no site-specific cleanup level associated with the UVSP for "commercial land use".

2.2.5.1 Sampling

This section says "Each of the working areas of the ESSA ... will be divided into 5, 000 square foot grids and sampled for arsenic, copper, lead, tin, zinc and boron. Each grid will be sampled by collecting nine equally-spaced grab samples from within the grid. " This section goes on and says "If laboratory analytical results for a given grid are below the site-specific cleanup levels (CLs) for commercial land use, the soils within the grid will be eligible to remain in place or be used as restoration material (e.g., soil associated with storm water diversion berms). " Immediately adjacent to the proposed ESSA, and lying only 100 feet from the Soil Repository, lies property that has an approved Development Agreement for a mixed use Planned Area Development in the Town of Clarkdale. That said, sometime in the future this immediately adjacent property may be residentially developed and Residential CLs should be used, not "Commercial" (Non-Residential) CLs to determine if remediation is required at the ESSA or if the soil is eligible to remain in place. In addition, if Freeport is compliant with the APP and implements a proper Storm Water Pollution Prevention Plan (SWPPP), using soil that exceeds the Residential CLs cannot and should not be used as "restoration material" because impacts would likely be spread to nearby sensitive habitats and surface waters.

2.3 Storm Water Management

This section seems to infer that storm water controls will be in place and managed only during the Soil Program. Freeport needs to make it clear that a compliant SWPPP will be developed and implemented in perpetuity to prevent erosion or water runoff from the Soil Repository. This is most important because

9


November 14, 2016

there is a surface-water body and a sensitive marsh nearby that could receive eroded and possibly contaminated soil or water. This would likely be required by the APP and SWPPP programs which Freeport should be required to implement as they relate to this RA WP.

Appendix C Soil Repository Operations Plan

2. Site Work

2.1.1 Clearing Grubbing and Grading

Comment: Six inches of suitable aggregate placed on top of a geotextile fabric should be considered the minimum control to minimize tracking soil, dust, or mud onto public right-of-ways. Provisions should also be made for street sweepers and exit grids if the minimum control fails to contain soil within the ESSA.

2.1.2 Erosion Control

Comment: Erosion control measures should be maintained in perpetuity around the Soil Repository, not just around the ESSA during the duration of the Soil Program cleanup activities. This would likely be required by the APP program which Freeport should be required to implement as it relates to this RA WP.

2.2.4 Restoration

Comments: How will water drain from the lined basin? Will the Soil Repository be capped at ground level, or will there be a mound created at the site?

2.6 Long-Term Operation and Maintenance

Comments: Section 2.6-Freeport plans to annually inspect, more frequently after a heavy rain, document, repair, and submit to ADEQ an annual report. The Town disagrees that management of this facility should stop after 10 years and Freeport must justify that 10-year limit in terms of regulatory programs that should be followed such as the APP and SWPPP.

The section also says "At the completion of the UVSP, a declaration of environmental use restriction (DEUR) will be added to the property where the soil repository will be located. " Freeport should clarify that this DEUR will be prepared and filed at the beginning of the active UVSP, before soil is received by the facility. Additionally, Freeport must describe their financial assurance plan, compliant with the APP or some other appropriate requirement.

There is no mention that groundwater monitoring wells will be installed and sampled to confirm that the "soil cap" and "liner" is functioning properly and that contaminants are not leaching into groundwater. At a minimum, Freeport should justify why they do not plan to monitor groundwater. This would likely be required by the APP program which Freeport should be required to implement as it relates to this RAWP.

Fourth paragraph/Notation should be added that the rainfall will be measured at the nearest weather monitoring station at Tuzigoot National Monument.

10


November 14, 2016

Appendix D Storm Water Management Plan

1. Introduction

Comment: Does Freeport intend to submit the required Notice of Intent (NOi) which is required by the referenced General Permit. If Freeport does not plan to submit a NOi how can Freeport be compliant with the referenced General Permit?

2. Regulatory Basis

Comments: Freeport should confirm that they will be compliant and follow the most current General Permit and that General Permit will require a SWPPP. Why is Freeport planning to use what appears to be an expired General Permit (AZG2008-001) that may have expired February 28, 2013.

Freeport needs to confirm that the ADEQ Water Quality Division specifically reviews and approves this plan. It appears that Freeport's Storm Water Management Plan (SWMP) may be deficient and not a compliant Storm Water Pollution Prevention Plan (SWPPP).

3 .2 Erosion Control Measures

Comment: This section says "Erosion control measures will be implemented for the duration of the voluntary soil cleanup operations in the ESSA, BSA, and Soil Repository. " Freeport should clarify if this also means during the active program, the 10-year inspection period, and thereafter.

4. Inspection and Maintenance

Comment: Reference should be incorporated that the monitoring station at Tuzigoot Monument shall be used so the location accurately reflects rain events at the Soil Staging Area and Soil Repository.

This section says that the storm water management features will be inspected as soon as practicable. If Freeport plans to implement the referenced General Permit (AZG2008-001) then the permit requires that an inspection occurs within 24 hours of the end of each rain event of 0.5- inches or greater; not

when practicable, and not after % inches of rain. Freeport should develop and implement a SWPPP compliant with the referenced General Permit or the most current and applicable General Permit.

5. Monitoring Program Review and Modification

Comment: This section says that if a discharge occurs, the receiving stream will be sampled. Because this SWMP does not appear to be a complete SWPPP, discharge conditions and the receiving stream are not acknowledged or described. At a minimum, Freeport should implement a compliant SWPPP and ensure that there are no discharges to any receiving stream or sensitive habitats.

11

1

James Kienholz

From: Voss, Alicia <[email protected]>Sent: Friday, June 23, 2017 10:39 AMTo: John C. Patricki ([email protected])Cc: Kienholz, James; Mueller, Stacy; David Wallis ([email protected])Subject: draft Response to Comments, UVSP draft Remedial Action Work PlanAttachments: DRAFT RAWP Response to Comments June 2017.docx

John, Freeport Minerals Corporation (Freeport) is responding to comments from the Arizona Department of Environmental Quality (ADEQ), the Town of Clarkdale (TOC), the National Park Service (NPS), Yavapai County and a Clarkdale resident on the October 4, 2016 draft Remedial Action Work Plan (RAWP) proposed for the United Verde Soil Program (UVSP), which is being conducted under the Voluntary Remediation Program. Freeport’s responses to the comments are attached in the attached draft document. Please note that we are still pursuing a permanent location for the soil repository and therefore some of the comments pertaining to the planned location of the soil repository in the draft RAWP last October are now dated since we are pursuing several possible repository locations that require changes in land use permitting. If you would like to discuss these responses further, please do not hesitate to contact me at your earliest convenience. Otherwise, if the responses are acceptable to ADEQ, please respond accordingly and Freeport will submit the final RAWP to ADEQ for your records. We anticipate that the final RAWP will be amended in the near future to include the final repository location when it land use permitting has been completed.

Alicia C. Voss Freeport Minerals Company 333 N Central Avenue Phoenix, AZ 85004 602‐366‐8049 (o) 602‐316‐5467

_____________________ This e-mail has been scanned for viruses

DRAFT RAWP Response to Comments 1

Responses to Comments - AttachmentDRAFT Remedial Action Work Plan (RAWP)

United Verde Soil ProgramClarkdale, Arizona

June 2017

RESPONSES TO ARIZONA DEPARTMENT OF ENVIRONMENTAL QUALITY (ADEQ)COMMENTS

Comment #ADEQ.GENERAL.1 [TOPIC - GENERAL]

Pursuant to Arizona Revised Statutes (A.R.S.) § 49-175, all known applicable permits must be obtainedfor the work to be performed at the site. Any subsequent approval of this RAWP does not constitute anexemption from required permitting under Title 49. In addition, applicable or relevant and appropriatepermit requirements may not be limited to requirements under Arizona statute and rule, but must still beadhered to as required by law.

UVSP Response

Agreed.

Comment #ADEQ.GENERAL.2 [TOPIC – REPOSITORY/ESSA]

For the purpose of providing clarification to the public and ADEQ, please clearly and with reference to anyapplicable or relevant and appropriate requirement, or industry approved guidance, explain to the VRPwhy a Solid Waste Storage Facility Aquifer Protection Permit (APP) or an APP would not be required toconstruct and maintain the Excavated Soil Staging Area (ESSA) and the capped Soil Repository (SR). Inaddition, clarify why a permit would not be required for the treatment, storage, and disposal of the soilassociated with the ESSA and SR.

UVSP Response

Management of soil at the ESSA and SR will be subject to several specific exemptions under Arizona andfederal law. First, at the broadest level, facilities that engage in “[s]torage, treatment or disposal of inertmaterial,” or in “remedial actions” approved under applicable state law, are not required to obtain an APPor solid waste facility approval. A.R.S. §§ 49-250.B.18&20; 49-701.15, 49-701.01.B.12&17. Similarly,under A.R.S §§ 49-241 through 49-252, an APP only is required if a facility discharges a pollutant eitherdirectly to a groundwater aquifer, to the land surface, or the subsurface vadose zone in such a mannerthat there is reasonable probability that the pollutant will reach the aquifer. An APP is not required for theproposed SR for the additional reasons that a) soil analysis will be conducted to demonstrate, by methodsaccepted by ADEQ that pollutants will not leach to the aquifer, land surface or vadose zone from the soil,or b) soil that exhibits leachable pollutants will be treated with stabilizing agents until the soil is no longerleachable. Therefore, as a practical matter, any soil that is placed in the SR will meet the exemption for“inert material,” or be treated to meet that exemption pursuant to the approved RAWP. Similarly, theESSA will be subject to “remedial action” per the terms of the approved RAWP and is not required to havean APP or solid waste facility approval.

Finally, ADEQ has attained authorization to implement the Resource Conservation & RecoveryAct (“RCRA”) “hazardous waste” program in Arizona, and oversee federal “hazardous waste”requirements within the State. 40 C.F.R. § 272.151. EPA’s “Area of Contamination” (“AOC”) Policy, which


Arizona follows, provides that contaminated materials from discrete sub-areas across a broader area ofgenerally dispersed contamination may be moved within the broader AOC without triggering RCRArequirements, including land disposal restrictions, minimum technology requirements, or other generationresponsibilities related to “hazardous waste.” See generally EPA, “Area of Contamination Policy” (March25, 1996), available athttps://www.epa.gov/hw/resource-conservation-and-recovery-act-rcra-area-contamination-policy. TheESSA and SR will serve to consolidate, treat, and manage soils from within the AOC, which is defined bythe outward extent of dispersed contamination that the UVSP is remediating on certain residential andcommercial properties. The ESSA and SR will be located within the AOC based on available samplingdata and air dispersion modeling, and therefore, movement and management of impacted soil to andwithin the ESSA and SR will not trigger RCRA obligations. This is consistent with the intent of the AOCPolicy, which was designed to facilitate remedial activities within the boundaries of AOCs.

Comment #ADEQ.GENERAL.3 [TOPIC – REPOSITORY/ESSA]

As the ESSA and SR are outside the site boundary/Area of Concern, FMC must indicate whether anypermits are required to transport waste from its point of origin to the ESSA, taking into consideration thewaste will be transported across properties not owned or managed by FMC.

UVSP Response

For the same reasons responding to comment [#ADEQ.GENERAL.2], the transportation and managementof soil will not trigger “hazardous waste” regulation, based on the AOC Policy. This same approach wasapproved by ADEQ for the Soil Programs located in Ajo, Bisbee and Douglas, Arizona.

Comment #ADEQ.GENERAL.4 [TOPIC - SWPPP]

FMC acknowledges the need for a State of Arizona Pollutant Discharge Elimination System (AZPDES)Construction General Permit, as cited in Appendix D. In addition, a Notice of Intent is required for anAZPDES Storm Water Construction General Permit (AZG2013-001). Furthermore, Peck's Lake isdesignated as an "Outstanding Arizona Water" for low dissolved oxygen and high pH, and is locatedwithin a ¼ of a mile of the proposed location of the ESSA and SR. As such, FMI must submit a SWPPP toADEQ for review, along with the Notice of Intent, if any part of the project is within 1/4 mile of any impairedor outstanding Arizona water. Freeport should submit the Notice of Intent for Construction ActivityDischarges to Waters of the United Sates under AZPDES Stormwater Construction GeneralPermit (AZG2013-001) and the SWPPP (ADEQ templates are available) to the ADEQ Water QualityDivision - Surface Water for review and approval.

UVSP Response

Agreed.

Comment #ADEQ.SPECIFIC.1 [TOPIC – EXCAVATION]

The Sampling and Analysis Plan indicates that soil sampling will continue in 6-inch intervals until dataindicate there are no exceedances of the risk based cleanup levels. However, the RAWP indicates


Freeport will only excavate to 2 feet. FMC should provide clarification on the process for instances whereexceedances occur below the 2-foot interval.

UVSP Response

Revisions will be made to this Section of the RAWP to provide clarification. Samples that have currentlybeen analyzed for the UVSP have shown that less than one percent of use areas have an exceedance ofapplicable soil remediation levels in the 18 – 24” depth interval (Interval D). If the property owner hasgranted permission to the UVSP to perform soil cleanup activities, the UVSP sampling teams will return tocollect deeper samples for subsequent analysis. Pending analytical results and the ability to perform thework safely, the UVSP will perform cleanup to depths deeper than 24 inches.

Comment #ADEQ.SPECIFIC.2 [TOPIC – BACKFILL]

Section 3.1.10. FMI should include the Backfill Staging Area on Figure 1.

UVSP Response

The location of the Backfill Staging Area (BSA) is typically selected by the soil cleanup and restorationcontractors during the bid process. There may or may not be a Backfill Staging Area depending on ifmaterials are direct-hauled from the source to the property. The location will be selected as such to avoidthe potential for cross contamination between the BSA and ESSA.

Comment #ADEQ.SPECIFIC.3 [TOPIC – BACKFILL]

Section 3.4: If known at this time, FMI should include a discussion of the origin of the soil that will be usedas backfill on properties requiring excavation.

UVSP Response

The source of backfill materials is typically selected by the soil cleanup and restoration contractors duringthe bid process in order to obtain competitive pricing. Prior to placement, all replacement materials will besampled and analyzed in accordance with Section 7 of the ADEQ-approved QAPP for the UVSP.

Comment #ADEQ.SPECIFIC.4 [TOPIC – EXCAVATION]

Appendix A: Fugitive Dust Control Plan. VRP understanding is that FMC will conduct soil excavationactivities (noise, dust, etc.) within the Town of Clarkdale (TOC) in compliance with the TOC ordinance,Town Code of the Town of Clarkdale, Arizona, Chapter 7: Building. For clarification, please note that anyexcavation activities relating specifically to the ESSA and SR are subject to the requirements of theAZPDES and SWPPP, and the requirements administered by Yavapai County.

UVSP Response

Agreed.


Comment #ADEQ.SPECIFIC.5 [TOPIC – REPOSITORY/ESSA]

Appendix B: Excavated Soil Staging Area Operations Plan.

a) Section 2.2.3. FMC should clarify the regulatory authority for staging soil within the ESSA for oneyear.

b) The Toxicity Characteristic Leaching Procedure (TCLP) regulatory thresholds are cited in thedocument. However, for determining whether a contaminant in soil is considered inert as definedby A.R.S. §§ 49-201 and 49-701, FMC should list the aquifer water quality standard for therespective contaminants for comparison to the Synthetic Precipitation Leaching Procedure (SPLP)data.

UVSP Response

a) Revisions will be made to the RAWP to provide clarification. Soil in the staging area may bestored for up to a year before triggering solid waste storage facility requirements. Accordingly, soilin the staging area will be removed within one year. Typically, stockpiles are removed from theESSA to the Soil Repository in one to two months of initial placement. The duration of thestockpile within the ESSA mainly depends on if treatment is required or if the Soil Repository isprepared to accept material.

b) The comment is acceptable and a revision will be made to the RAWP.

Comment #ADEQ.SPECIFIC.6a [TOPIC – REPOSITORY/ESSA]

Appendix C: Soil Repository Operations Plan. FMC indicates the engineering controls associated with theESSA and SR will be inspected and maintained for a period of 10 years, and then a Declaration ofEnvironmental Use Restriction (DEUR) will be utilized upon the completion of the United Verde SoilProgram (UVSP). For clarification, the VRPs understanding is that the following requirements will be met:

a) FMC must monitor and maintain the ESSA and all respective stormwater controls as addressed inthe AZPDES and SWPPP until the completion of the UVSP.

b) Upon completion of the UVSP, ADEQ will require a DEUR utilizing land use restrictions andrespective engineering controls (diversion berms, ditches, silt fences, capping, etc.) to ensure thelong term monitoring and maintenance of all respective controls. In addition, pursuant to A.R.S. §49-152.01, an engineering control plan and financial assurance are required and are subject toADEQ approval.

c) FMC should clarify the rational for citing 4 inches of rain within a 24-hour period as a "heavy" rainevent, since this is cited as the trigger for conducting an inspection.


UVSP Response

a) Agreed.

b) Agreed.

c) NOAH Atlas 14 Point Precipitation Frequency Estimates near Clarkdale, Arizona estimate therainfall depth to be 3.85 inches for a 100-year, 24-Hr probability storm event. This estimate wasrounded up to 4 inches. A reference will be added to the RAWP.

Comment #ADEQ.SPECIFIC.6b [TOPIC – REPOSITORY/ESSA]

Appendix D: Storm Water Management Plan for the Excavated Soil Staging Area and Soil Repository.

a) This is subject to the requirements cited in "General Comment #4."

b) Figure D-1 Excavated Soil Staging Area Storm water Management Plan Details. FMI shouldinclude a figure drawn to scale depicting the layout of the respective features of the ESSA andSR, to include driveway, wash area, stockpile area, treatment area, etc.

UVSP Response

a) Agreed.

b) The comment is acceptable and a revision will be made to the RAWP.

Comment #ADEQ.SPECIFIC.6c [TOPIC – REPOSITORY/ESSA]

The VRP's understanding is that a subsequent Indoor Dust Cleaning Plan will be submitted, whenappropriate as part of the UVSP.

UVSP Response

Correct.

Comment #ADEQ.OVERALL.1 [TOPIC – OVERALL]

Upon completion of a 30-day public comment period (October 15 through November 14, 2016) for theRAWP, the VRP received public comments from four separate interested parties. These comments areprovided as attachments to this letter. The VRP requests that FMC respond to the VRP's comments, aswell as the public comments, in one responsiveness summary or Response to Comments submittal. TheVRP will review FMC's submittal and respond accordingly. FMC should not revise the RAWP until suchtime the VRP has reviewed the submittal and determined if any additional changes and/or amendmentsare necessary based upon the responses provided.

UVSP Response

Agreed.


RESPONSES TO TOWN OF CLARKDALE (TOC) COMMENTS

Comment #TOC.1 [TOPIC - REPOSITORY/ESSA]

The Town of Clarkdale has concerns about the proposed location for the Excavated Soil StagingArea (ESSA) and the Soil Repository. Both lie on property that is currently zoned for residential use byYavapai County, and both areas are within 100 feet of property within the Town of Clarkdale, which has azoning entitlement for Verde Valley Ranch, a proposed mixed-use development with 900 residential units.

UVSP Response

If Freeport retains the proposed location of the ESSA and the Soil Repository, UVSP will obtain aConditional Use Permit from Yavapai County prior to placement of any excavated material within theproposed Soil Repository. The UVSP will also obtain any required permitting for work located within theTown of Clarkdale limits. A secondary ESSA location north of the Town of Clarkdale is being pursuedunder the same Conditional Use Permit requirements from Yavapai County.


Both the ESSA and the Soil Repository are also immediately adjacent to Tavasci Marsh, which is acomponent of the Verde River system, a part of Tuzigoot National Monument and habitat for many uniqueand sensitive species. An Aquifer Protection Permit (APP) must be obtained to own or operate a facilitythat discharges a pollutant either directly to an aquifer, to the land surface, or the vadose zone in such amanner that there is a reasonable probability that the pollutant will reach an aquifer. Due to proximity toTavasci Marsh, groundwater is expected to be shallow, possibly within a few feet of the bottom of thecurrently existing lined "pond" that was designed and constructed in the past, and never utilized, as aneffluent holding facility. It is reasonably probable that metals or soil containing elevated concentrations ofmetals will impact the shallow aquifer, Tavasci Marsh, and Verde River. That said, Freeport mustdemonstrate that using the existing lined retention pond to contain impacted soil will be compliant with theAPP program and be the most appropriate Best Available Demonstrated Control Technology (BADCT) asdescribed in this RAWP.

UVSP Response

Please see response to comment #ADEQ.General.2 regarding why an APP is not required for the ESSAor Soil Repository.

Comment #TOC.3 [TOPIC – REPLACEMENT MATERIALS]

The RAWP lacks any reference to the replacement soil for the project. At a minimum, the plan shouldaddress the location and source for replacement soil for the project, the sampling and analysis protocolthat will be used for the replacement soil, any transportation impacts relating to the replacement soil, andany permitting issues that may arise due to the location and process for excavating replacement soil.Backfill or replacement soil should be selected to ensure that it is a suitable replacement for the removednative soil in characteristics, texture and structure.

UVSP Response

The source of backfill/replacement materials is typically selected by the soil cleanup and restorationcontractors during the bid process; however, backfill materials including sod, general fill, decorative rock


and other materials will be analyzed to ensure they meet the requirements as discussed in Section 7 ofthe ADEQ-approved Quality Assurance Project Plan (QAPP) for the UVSP. Additional testing will beconducted on backfill soil to ensure adequate characteristics such as texture and structure are available tosupport vegetation growth.

Comment #TOC.4 [TOPIC – INTERIOR CLEANING]

Property owners who participate and have their properties remediated should be offered the option ofhaving the interior of homes cleaned after the remediation process in the event that dust may have gotteninto the house during the remediation process. (Note: This addition aligns with a statement by a FMCrepresentative at the May 19, 2015 Clarkdale public meeting.)

UVSP Response

Interior cleaning is not addressed within the Remedial Action Work Plan (RAWP) or the VRP; however,participation in an interior cleaning program is anticipated for those parcels that have participated in soilcleanup activities. Details for such a program would be discussed under a separate work plan.


Section 3 .4 asserts that "The material excavated from the cleanup properties that is hauled to the ESSAwill not be considered to be hazardous waste pursuant to the applicable regulations of the ResourceConservation and Recovery Act (RCRA) because it remains within the area of concern, thereforetransporters of this material will not require licensing as hazardous waste transporters." Freeport needs tobetter explain how the ESSA and Soil Repository can be considered the same "area of concern" as eachindividual property in the designated Project Area within the Town.

UVSP Response

As more fully explained in response to comment [#ADEQ.GENERAL.2], the transportation andmanagement of soil will not involve “solid waste” or “hazardous waste” regulation, based on the AOCPolicy as well as specific Arizona exemptions to the definition of “solid waste.”

In brief, the Area of Contamination (AOC) Policy under RCRA allows movement of soil with thedesignated AOC without triggering land disposal restrictions or minimum technology requirements. TheAOC for the UVSP has been designated as the Study Area (and any expansions deemed appropriate). Inthis case, soil can be moved within the AOC without triggering transportation licensing requirements foreach haul truck. Soil also does not have to be tested for leachability until it reaches the designatedmanagement area or ESSA.

Comment #TOC.6 [TOPIC – GENERAL]

The RAWP lacks consistency with statements made by Freeport representatives at public meetings inClarkdale, and with responses to concerns previously brought forward by the Town during review of theSampling and Analysis Plan for the UVSP.

UVSP Response

Freeport cannot respond to non-specific comments on inconsistency at this time. Freeport is willing todiscuss any specific comments from interested parties.


Comment #TOC.7 [TOPIC - TRANSPORTATION]

The RAWP lacks specifics for planning for increased commercial traffic and other impacts on TuzigootRoad and/or Sycamore Canyon Road. Tuzigoot Road is owned and maintained by the National ParkService, and is often used by pedestrians who recreate in the area.

UVSP Response

A Traffic Control Plan will be developed for soil cleanup and restoration activities for the UVSP as part ofthe Grading Permit process. This will be submitted to the Town of Clarkdale for review and approval.

Comment #TOC.8 [TOPIC - GENERAL]

Freeport needs to explicitly say in this RAWP that Freeport will be the generator of any and all solid andhazardous wastes associated with the United Verde Soil Program.

UVSP Response

For the same reasons responding to comment [#ADEQ.GENERAL.2], the management of impacted soilwithin the AOC will not trigger requirements typically associated with “solid waste” or “hazardous waste”regulation under RCRA, based on the AOC Policy as well as specific Arizona exemptions to the definitionof “solid waste.” However, to the extent that Freeport generates impacted soil that qualifies as “solidwaste” or “hazardous waste” under ADEQ regulations, and transports that material beyond the AOC,Freeport will properly characterize, manage, and dispose of such soil consistent with the applicablegenerator regulations of ADEQ.

Thus, Freeport will be the designated generator under RCRA of solid and hazardous wastes (if any) fromthe UVSP.


There is no reference to coordination with Yavapai County on permitting requirements that may benecessary due to the location of the proposed ESSA and the Soil Repository within residentially zonedproperty located in Yavapai County.

UVSP Response

See response to Comment #TOC.1.

Comment #TOC.10 [TOPIC - TEXT]

Section 1, Introduction - Third paragraph/first sentence should be rewritten for accuracy. Both ADEQ andthe Town of Clarkdale have raised question in the past as to the reason that the initial Study Area was


selected and how that Study Area will be expanded in the future. We recommend the followingamendment to improve the accuracy of the statement:

'The Study Area, exclusive of the original smelter site, includes most some properties likely to have beenaffected by ...’

UVSP Response

Provisions for adjustments to the Study Area are provided in Section 1.4 of the ADEQ-approved Samplingand Analysis Plan (SAP) for the UVSP. As the RAWP will pertain to any Study Area revisions required bythe SAP, the UVSP believes that a revision to this sentence is not warranted.


Section 1.1, Soil Cleanup Objective: first paragraph – “The objective of the UVSP…within individual ...”

UVSP Response

UVSP believes that a revision to this sentence is not warranted.


The town requests clarification of Table 1.1 as to which Cleanup Level will apply to Town Parks.

UVSP Response

Analytical results for samples collected within parks will be compared to cleanup levels for residential landuse.


The RAWP does not include any details relating to the replacement soil that will be used for this project.

UVSP Response

Please see the response to Comment #TOC.3.


Section 3.1.1 Property Access: Third paragraph/last sentence - property owner or their representative

UVSP Response

The comment is noted and a revision will be made to the RAWP.


Section 3.1.2 Town of Clarkdale Permits: First paragraph/First sentence: ... to grading and rights-of-waypermits and any other legal requirement of the Town of Clarkdale.

UVSP Response




Section 3.1.2 Town of Clarkdale Permits: First paragraph/Second sentence: excavations greater than orequal to 50 cubic feet, a grading permit and rights-of-way permit, if necessary as required, will be...

UVSP Response



Article 7-11 Excavation and Grading of the Town of Clarkdale Town Code as amended by Ordinance#371 requires a permit for ALL projects involving cut and fill of materials. This requirement is not based onthe quantity of cut and fill.

UVSP Response

Noted.


Section 3.1.3: Second paragraph/third sentence - remediation may.... Flowerbeds (unless the ownerrequests otherwise); and other landscaped treatments and...

UVSP Response

Changes will be made to clarify this portion of the RAWP.


Section 3.1.3: Fifth paragraph/second sentence - delete the word physically.

UVSP Response



Section 3.1.3: Language should be added to this paragraph addressing the process forrelocating/boarding pets, poultry and livestock.

UVSP Response

Revisions will be made to this Section of the RAWP to provide clarification.


Language should be added that CPC will arrange and pay for off-site storage if required as previouslycommitted to by FMI representatives.

UVSP Response

Revisions will be made to this Section of the RAWP to provide clarification.


Comment #TOC.22 [TOPIC - EXCAVATION]

Section 3.1.4 Excavation Activities: Fourth paragraph/second sentence states that excavations will beperformed to a maximum depth of two feet.

Comments: This Section is inconsistent with statements made during a public meeting in Clarkdale onMay 19, 2015, where Freeport's Project Manager Alicia Voss said 'they may go deeper than 2 feetdepending on the test results found at the 2 feet depth...' Terminating excavations at a maximum depth oftwo feet without collecting and analyzing soil at the base of each excavation is unacceptable, not typicallyallowed by any regulatory agency or State or Federal regulation, and is not standard practice if impacts insoil exceed a certain cleanup concentration; in this case, the "Residential Cleanup Level by LandUse" (CL) for each "Target Constituent" (TC). If samples collected and analyzed from "Interval D" indicatethat any TC concentration exceeds a CL then further sampling must be completed at and below 24 inchesto properly and responsibly determine if impacts reside deeper than this RAWP contemplates. This datawould then be used on a case-by-case basis to determine if that soil should be removed to furtherminimize human contact in the future should the property owner make improvements to their property thatcontacts soil at that depth. That said, Freeport has an obligation to inform each property owner if soilresiding at or below 24 inches is impacted above a CL for any TC so that the property owner can beinvolved with how this matter is resolved.

Additionally, Freeport should be obligated to add a declaration of environmental use restriction (DEUR) toeach property where remediation is completed and impacts are left in place at or below 24 inches.

UVSP Response

Please see the response to Comment #ADEQ.SPECIFIC.1.


Section 3.1.4 Excavation Activities: Seventh Paragraph - Add the following language: Utility companiesshall be notified of any damage to their infrastructure and a Town of Clarkdale permit shall be required forrepair to water, gas and electric lines and infrastructure.

UVSP Response



Section 3.1.4 Excavation Activities: Eleventh Paragraph-Add the following language: Removal or locationof existing fences shall be noted on the original Town of Clarkdale grading permit submission if possible,or submitted as an addendum to the original permit to assure accuracy of the permanent property filerecords at the Town of Clarkdale.

UVSP Response




Section 3.1.4 Excavation Activities (continued): In Section 3.1.4, Freeport says that properties will besampled according to the Sampling and Analysis Plan (SAP) (GHD, 2015a). The Town is highlyconcerned that Freeport is not planning to sample the 3-6 inches interval and Freeport claims that "the 0-3inch interval is used to best represent the surface soil that may have been impacted by air deposition fromthe former smelter. Furthermore, the 3-6 inch interval is not likely to have more air deposition impact thanthe 0-3 inch interval. As will be explained in the RAWP, if the 0-3 inch interval exceeds any TC, the 0-6inch interval will be removed as a practical excavation technique and, and therefore, is addressed. "TheTown did not see that clarification in this RAWP as promised by Freeport and that should be included inthe final RAWP.

UVSP Response

This comment is noted and changes will be made to clarify this portion of the RAWP.


Additionally, the Town agrees that the current approach to remove the 0-6 inches interval 'practically'address this concern. However, unless Freeport plans to collect a statistically significant number ofsamples from all intervals, including the 3-6 inches interval and analyze those samples for each TC, thenthis approach and Freeport's explanation is flawed. Freeport's explanation is flawed because the 3-6inches interval can exceed the 0-3 inches interval TC concentrations because deposition from the smelterstopped approximately 60 years ago. During the last 60 years, TCs have likely leached deeper, the soil atmany if not all properties has been disturbed and impacts redistributed into the 3-6 inches interval, andintentional and natural soil accumulation at land surface of native soil not impacted by the smelter (the 0-3inches interval) can likely be the interval with the lesser impacts. Unless Freeport plans to demonstratewith data rather than a potentially flawed theory, that "the 3-6 inch interval is not likely to have more airdeposition impact that the 0-3 inch interval", then the 3-6 inches interval should be sampled and analyzedin the event the 0-3 or the 6-12 inches intervals demonstrate that CLs are not exceeded at 0-3 or the 6-12inches intervals, and therefore no remediation potentially occurs.

UVSP Response

The 0-3 inch interval and 6-12 inch interval are routinely analyzed. It is Freeport’s experience that the 0-3inch interval typically exhibits the highest concentrations of target metals and as a matter of constructionpracticality, the 3-6 inch interval is removed automatically. Soil data collected for the UVSP has shownconsistent correlation between elevated concentrations of target metals in both intervals (i.e., consistenthigh exceedance rates).


The Town highly recommends that Freeport follow a more typical sampling and analysis approachimplemented under Order and Consent by the United States Environmental Protection Agency (USEP A),Region 4, whereby the Responsible Parties (RPs) were obligated to follow the provisions of the agreedupon "Administrated Agreement and Order on Consent for Removal Action" relating to the Anniston LeadSite (AOC). Phelps Dodge Industries, Inc. (Freeport) was a "Respondent" in that matter.


In the Anniston Lead Site Quality Assurance Project Plan dated March 15, 2005, Section 4.0, SamplingRationale, references used to prepare the sampling methods are:

A Compendium of Superfund Field Operations Methods (EP N540/P-871001

Samplers and Sampling Procedures for Hazardous Waste Streams (EPA-600/2-80-018)

Test Methods for Evaluating Sold Wastes-Physical/Chemical Methods (EPQ SW-846, Third Edition,April 1998)

Superfund Lead-Contaminated Residential Sites Handbook (OSWER 9285.7-50, August 2003)

XRF SW 846 Draft Method 6200.

Section 4 goes on to say... "Confirmation sampling will consist of a screening XRF sampling/or lead and acomposite laboratory analyzed sampling/or lead. XRF screening will be performed at the base ofexcavations to verity the complete removal of soils with lead concentrations above 400 ppm and todelineate areas, if any, that require additional excavation and removal. Composite soil samples will becollected from the base of excavations and sent to a laboratory for confirmation that the remaining soilmeets the removal confirmation criteria of 400 ppm lead, as specified in the AOC " Section 4.1.1 of theQAPP further says that "After excavation is complete, and XRF screening has demonstrated that leadconcentrations in subgrade soils are less than 400 ppm, a composite sample will be collected from thebase of the excavation for laboratory analysis of total lead " That said, Freeport should revise this draftRAWP and simplify the approach by collecting and analyzing samples from each interval to determine theconcentrations of each TC and remediate accordingly. Additionally, confirmation samples should becollected from the base of each excavation to demonstrate that subgrade soils are less than each CL foreach TC. The City believes this approach will satisfy the concerns relating to not collecting and analyzingsoil samples from the 3-6 inches interval. Alternatively, the City's concerns can be minimized if Freeportplans to collect a statistically significant number of samples from all intervals, including the 3-6 inchesinterval and analyze those samples for each TC to demonstrate the approximate concentrations, at depthin soil for each TC and prove that "the 0-3 inch interval is used to best represent the surface soil that mayhave been impacted by air deposition from the former smelter.”

UVSP Response

This comment was addressed in Freeport’s response to comments on the SAP [Comment#TOC.26].


Why is Freeport not using an x-ray fluoresce analyzer to screen soil in the field to determine in real timethe approximate concentrations of each TC in soil at each interval, including the base of each excavation?

UVSP Response

Freeport relies on laboratory data, which is more consistent and reproducible, to predetermine excavationdepths so that remediation planning and execution is conducted in an efficient manner.



Section 3.1.5 - Loading Excavated Materials: Third Paragraph/second sentence: Dust control methods incompliance with Town of Clarkdale regulations will be maintained...

UVSP Response



Section 3.1.6 Noise Control: Add the following language: Article 10-1-11 of the Town of Clarkdale Towncode shall apply to noise complaints submitted to the Town of Clarkdale, regardless of the CPC’sassessment.

UVSP Response



Section 3.1.7 – Dust Control: Per Section 7-11. Q of the Town of Clarkdale Town Code, either a dustpalliative or reclaimed water shall be used for the alleviation or prevention of dust. Dust control methodsconsistent with the 2012 International Building Code as adopted by the Town of Clarkdale and with Article7-11 Excavation and Grading of the Town Code shall be enforced including the cessation of all activityduring active red flag warnings.

UVSP Response



Section 3.1.8 – Access for Property Residents: Add the following language: Should residents need torelocate during the remediation, the CPC or FMI will work with those residents and will cover thoseexpenses.

UVSP Response


Comment #TOC.33 [TOPIC – INTERIOR CLEANING]

Section 3.1.9 – Decontamination Procedures: Add the following language: Property owners will be offeredthe option of having the interior of homes cleaned after the remediation process in the event that dust mayhave gotten into the house during the remediation process. (Note: This aligns with a statement by a FMIrepresentative at the May 19, 2015 Clarkdale public meeting.)

UVSP Response




Section 3.1.9 – Decontamination Procedures: This Section should address the plan for rainy days.

UVSP Response



Section 3.1.10 – Backfill and Revegetation of Excavated Area: First paragraph, last sentence: In addition,all excavations over 50 cubic feet will require...

UVSP Response



Section 3.1.10 – Backfill and Revegetation of Excavated Area: Second paragraph/ Add the followinglanguage: Backfill or replacement soil should be selected to ensure that it is a suitable replacement for thenative soil in characteristics, texture and structure and conforms to the approved grading permit.

UVSP Response



Section 3.1.10 – Backfill and Revegetation of Excavated Area: Sixth paragraph - Replace the word desertwith xeriscape.

UVSP Response



Section 3.1.10 – Backfill and Revegetation of Excavated Area: Scheduling for the watering of anylandscape should coordinate with the Town of Clarkdale's Drought and Water Shortage PreparednessPlan. In addition, consideration shall be given as to whether the time of year is appropriate for plantingand replanting, given any watering restrictions in place at the time.

UVSP Response




Section 3.1.11.2 – Repair Work: Is there an appeal method for property owners?

UVSP Response

There is no formal method for appeal. UVSP personnel will work diligently with property owners to rectifyany damages caused by soil cleanup and restoration activities.


Section 3.2 – Excavated Soil Staging Area: Freeport needs to better explain its plan relating to activitiescontemplated at the Excavated Soil Staging Area (ESSA). This Section says that the property (the ESSAand Soil Repository) is owned by Freeport and that "at its own discretion, elect to treat the weeklyexcavated stockpile as described in the Excavated Soil Staging Area Operations Plan (Appendix B) ifthere is a history of untreated weekly excavated stockpiles exceeding the TCLP and/or SPLP thresholdconcentrations".

UVSP Response

The comment is noted and a revision will be made to the RAWP to provide clarification. Although it hashistorically not occurred at other town sites in Arizona, the UVSP is reserving the right to treat the weeklyexcavated stockpile before collecting initial samples to be analyzed using the TCLP and SPLPprocedures. If previous weekly excavated stockpiles have exceeded the TCLP or SPLP thresholdconcentrations, they will be moved to the Soil Treatment Area for treatment and subsequent re-analysisfor TCLP and SPLP. Weekly excavated stockpiles are not allowed to leave the ESSA for final disposal inthe Soil Repository until the threshold concentrations for TCLP and SPLP are below criteria. As thesetreatment and analytical procedures may take several weeks and analytical results for previous weeklyexcavated stockpiles show a high rate of exceedance of the TCLP or SPLP threshold concentrations,space may become limited within the ESSA due to the large backlog of weekly excavated stockpilesawaiting confirmation that treatment was successful. If the ESSA has reached capacity and can no longeraccept excavated material, soil cleanup activities at individual properties would be halted until furtherspace becomes available.


Freeport's concept of "area of concern" is too broad and not consistent with the Resource Conservationand Recovery Act (RCRA) or the National Contingency Plan (NCP) and cannot include commercial,public, residential properties and the ESSA and Soil Repository which are approximately 1.0 mile from thesubject commercial, public and residential properties being remediated; in general, the entire Town, publicland and land owned by Freeport cannot be considered an "area of concern". If Freeport desires to applythe "area of concern" concept allowed by RCRA, that "area of concern" must be limited to the subject andimpacted properties being remediated, and the ESSA and Soil Repository not be included as part of the"area of concern". That said, treating "Characteristic Hazardous Waste" at the ESSA must be consistent


with RCRA and a Treatment Storage and Disposal Part A and Part B permits must be obtained beforethese activities can be allowed.

UVSP Response

For the same reasons responding to comment [#ADEQ.GENERAL.2], management of soil within the AOCwill not involve “solid waste” or “hazardous waste” regulation based on the AOC Policy. By its own terms,application of the AOC Policy is not limited to discrete properties or sub-areas within an AOC wherematerial is actually generated or remediated (otherwise, the AOC Policy would be rendered meaningless):Instead, the AOC Policy applies to the broader area of generally dispersed contamination. The ESSA andSR will be located within the AOC, and therefore, movement and management of impacted soil to andwithin the ESSA and SR will not trigger RCRA obligations.

See response under #TOC.5 RCRA: TSD permits are not required for the UVSP to treat soil within theAOC.


Section 3 .2 does not describe how many samples will be collected per cubic yard of potentially"Characteristic Hazardous Waste" and how those samples will be handled to determine the impactscontained in the excavated soil removed from the subject properties. Appendix B does contain furtherinformation; however, Freeport should do a better job explaining the details associated with federalregulations relating to collecting representative samples, how Freeport is going to employ RCRArequirements, specifically "Test Methods for Evaluating Solid Waste: Physical/Chemical Methods, alsoknown as SW-846, in order to be consistent with RCRA. Because the ESSA likely cannot be part of theoverly broad "area of concern" currently being contemplated, Freeport needs to describe how theseactivities would be completed at each subject property, rather than the ESSA, in order to not violate RCRAand transport potentially "Characteristic Hazardous Wastes" on Town, County and Federally owned roadswithout proper permits. Further, Freeport needs to explain how and where "Characteristic HazardousWastes" will be disposed in a permitted Hazardous Waste landfill, and not treated at each subject propertycontained within the more reasonably sized "area of concern" because treatment at each property is notdesirable nor practical.

UVSP Response

For the same reasons responding to comment [#ADEQ.GENERAL.2], management of soil within the AOCwill not involve “solid waste” or “hazardous waste” regulation based on the AOC Policy.

In brief, the AOC is applicable to the UVSP and the ESSA and SR will be within the AOC boundary.Therefore characteristic testing of soil is not necessary at each property and can be conducted at theESSA. Testing methods are described in the SAP. Soil will be treated with a stabilizing agent and retesteduntil it meets the leachability criteria for each target metal, thereby not requiring disposal at a hazardouswaste landfill. In the event the soil cannot be successfully treated at the ESSA, Freeport will coordinatewith the ADEQ and inform the Town of Clarkdale of any changes to soil disposal.


What operations, maintenance, and monitoring activities will Freeport implement to ensure that this area isnot disturbed, waste is not removed, waste is not blown and spread, waste is not eroded by surface water,


and if and what type of groundwater monitoring will be implemented to ensure that a groundwater and/orsurface water resource is not impacted in the future?

UVSP Response

Freeport will secure the area so the public does not have access to the area. Dust control measures asoutlined in Section 3.1.7 and Appendix A of the RAWP to prevent soil from being blown and spread.Stormwater controls will be implemented pursuant to a SWPP to prevent soil from being eroded bysurface water. The soil will be rendered insert to it will not have a potential to leach metals intogroundwater.

Finally, the ESSA and SR will be fenced and monitored during and after completion of the UVSP. Freeportwill retain ownership of the property.


How will the excavated soil be profiled and managed if it fails either TCLP or the SPLP testingprocedures?

UVSP Response

The weekly excavated stockpile will be re-treated and re-analyzed if the initial analysis exceeds thethreshold criteria. This procedure will be repeated until analytical results for TCLP and SPLP are belowcriteria.


The area for the stockpiled material is outside the jurisdiction of the Town of Clarkdale and under theauthority of Yavapai County. The RAWP does not address any permit requirements from Yavapai County.

UVSP Response



Section 3.3 – Final Excavated Soil Management: Section 3.3 does not describe how the soil will be"profiled" and managed if that soil fails either the TCLP or the SPLP testing procedures. As stated above,Freeport's "area of concern" concept is not likely consistent with RCRA and excavated soil from eachproperty must be properly characterized and "profiled" before non-hazardous soil is relocated to the ESSAor Soil Repository, or to a Hazardous Waste Landfill depending on the TCLP or the SPLP results.

UVSP Response



Section 3.3 – Final Excavated Soil Management: Additionally, discrete samples must be collected at thebottom of each excavation so that at a minimum property owners understand deeper soil conditions attheir property to avoid being exposed to unacceptable soil impacts; or, these data should be used by


Freeport to further excavate impacted soil below 24 inches should soil impacts exceed the ResidentialCleanup Levels (CLs).

UVSP Response

The UVSP utilizes pre-excavation sampling to determine depth of excavation. At depth intervals below 12inches, sampling will be continued in 6-inch depth intervals until analysis results in a non-exceedance ofall CLs for a depth interval or if refusal is encountered. Refusal is defined in Section 3.1 of theADEQ-approved SAP for the UVSP. Additional sampling activities will not be conducted after soil cleanupactivities have been completed for the use area because the depth of soil impacts will be defined prior tosoil cleanup activities.


Section 3.3 – Final Excavated Soil Management: This Section also needs to address what happens towater that accumulates in the lined pond. Additionally, if the lining in the pond is integral to the project,Freeport should demonstrate that the integrity of the liner is appropriate for the project. The liner wasplaced in the pond more than 10 years ago, has been exposed to the elements, and has had very little, ifany, maintenance since that time.

UVSP Response

The Soil Repository will be constructed as to avoid accumulation of water. Final design cannot occur untilthe estimated quantity of material to be removed is established based on overall analytical results andproperty owner participation rates. Material placed in the Soil Repository will be “inert” and will not havethe potential to generate leachate with metals concentrations in excess of Arizona Drinking WaterStandards as demonstrated by the results of the TCLP and SPLP analyses; therefore, the liner is notrequired.


Section 3.4 – Soil Transportation: The borrow soil site needs to be identified. Documentation needs to beincluded as to how many samples per cubic yard will be collected and analyzed to determine the borrowsoil is from a suitable source. Freeport needs to describe how they are going employ US EnvironmentalProtection Agency (USEPA) guidance, or specifically SW-846 to determine the appropriate numbers ofsamples will be collected, treated, and analyzed. In addition to analyzing borrow soil for arsenic, copper,lead, tin, zinc, and boron; Freeport needs to also analyze potential borrow soil for benzene, toluene,ethylbenzene, and xylenes (BTEX), and for volatile organic compounds (VOCs).

UVSP Response

Please see response to Comment #TOC.3.

Comment #TOC.50 [TOPIC – TRANSPORTATION]

Section 3.4 – Soil Transportation: All transportation shall conform to the approved traffic plan for the initialgrading permit.

UVSP Response

Noted.



Section 3. 4 – Soil Transportation: 5th paragraph says "The material excavated from the cleanupproperties that is hauled to the ESSA will not be considered to be hazardous waste pursuant to theapplicable regulations of RCRA because it remains within the area of concern; therefore, transporters ofthe material will not require licensing as hazardous waste transporters." This Town disagrees withFreeport's concept of “area of concern". Freeport's concept is too broad and not likely consistent withRCRA or the NCP and cannot include commercial, public, residential properties and the ESSA and SoilRepository which are approximately 1 mile from the subject commercial, public and residential propertiesbeing remediated; in general, the entire Town, public land and land owned by Freeport cannot beconsidered an "area of concern". If excavated soil at each subject impacted property fails TCLP analyses,then Freeport needs to comply with RCRA in its entirety. Likewise, Freeport appears to assume it neednot comply with handling and transportation requirements because of the CERCLA exemption describedin § 121(e) of CERCLA, 42 USC 962l (e). Freeport needs to substantiate why it need not comply withthese requirements. Even where it applies, this CERCLA permit exemption only applies to work completedonsite and requires substantive adherence to this Section and permit requirements. Additionally, Freeportneeds to explicitly say in this RAWP that Freeport will be the generator of any and all solid and hazardouswastes. If Freeport desires to apply the "area of concern" concept allowed by RCRA, that "area ofconcern" must be limited to the subject and impacted properties being remediated, and the ESSA and SoilRepository not be included as part of the "area of concern". That said, treating "Characteristic HazardousWaste" at the ESSA must be consistent with RCRA and a Treatment Storage and Disposal Part A andPart B permits must be obtained before these activities can be allowed. Freeport should describe inwriting how their "area of concern" concept is allowable and consistent with Federal and State laws andregulations as they apply to this RAWP.

UVSP Response

For the same reasons responding to comment [#ADEQ.GENERAL.2], management of soil within the AOCwill not involve “solid waste” or “hazardous waste” regulation based on the AOC Policy. As notedpreviously, to the extent that Freeport generates impacted soil that qualifies as “solid waste” or “hazardouswaste” under ADEQ regulations, and transports that material beyond the AOC, Freeport will properlycharacterize, manage, and dispose of such soil consistent with the applicable generator regulations ofADEQ.


Section 3. 4 – Soil Transportation: Eight Paragraph/last sentence - Police reports for any incident onpublic property shall be filed with the Town of Clarkdale Police Department.

UVSP Response

The UVSP does not have jurisdiction over the Town of Clarkdale Police Department and how itspersonnel file their own police reports; however, any accident related to the UVSP will be reported to theproper authorities.


Comment #TOC.53 [TOPIC – TEXT]

Section 4.1 – Scheduling of Cleanup Properties: The regulatory reference is not appropriate for handlingwaste soil, profiling waste soil, transporting waste soil, accumulating waste soil, treating waste soil toremove "Hazardous Wastes" "Characteristics", or finally disposing waste soil to the land.

UVSP Response

The reference in the RAWP pertains to the prioritization of soil cleanup for individual properties within theUVSP. No change to the RAWP as related to this comment is needed.


Section 4.1 - Scheduling of Cleanup Properties: Recreational properties need to be referenced in thescheduling protocol.

UVSP Response

Recreational properties are mentioned at the end of Section 4.1. No change to the RAWP as related tothis comment is needed. The UVSP will work closely with the Town of Clarkdale to schedule theirrecreational and other properties.


Section 5 – Reporting: The Town of Clarkdale requests electronic version of all reports related to Townowned property, including but not limited to complete laboratory testing reports.

UVSP Response

Electronic versions of reports already are being provided to the Town of Clarkdale, and Freeport willprovide reports for the Town’s properties in electronic format.


Section 5.2.1 – Weekly Documentation: Add Total number of parcels declining remediation.

UVSP Response



Will maps at the parcel level be included in this weekly documentation? Will the Town of Clarkdale receivecopies of these weekly reports?

UVSP Response

Status figures are typically part of the weekly documentation; however, the Town of Clarkdale (nor ADEQ)will not receive the weekly reports. ADEQ and the Town of Clarkdale will continue to receive monthlyreports which are similar in nature to the weekly reports.



Section 5.2.2 – Monthly Reporting: The Monthly Progress Reports that have been delivered to ADEQ todate do not include the level of detail as described in the RAWP. Those submitted so far have notincluded the narrative descriptions relating to significant developments during the preceding period,including actions performed and problems encountered, the activities anticipated over the next month,schedule of anticipated actions, and anticipated problems and planned resolution of past or anticipatedproblems.

UVSP Response

Once the RAWP has been finalized and approved by ADEQ, the monthly progress reports will be revisedto meet the requirements outlined in the RAWP. Currently, the monthly reporting meets the requirementsof Section 8 of the ADEQ-approved SAP for the UVSP.


Section 5.3 – Final Report: Add the following: The Town of Clarkdale and the public will be provided theopportunity to comment on the Final Report.

UVSP Response



Section 6 – References: Fifth bullet point add: as revised by Ordinance #371, Resolution 1509 on11/10/15; Effective 12/11/15.

UVSP Response


Comment #TOC.61 [TOPIC – DUST CONTROL]

Appendix A – Fugitive Dust Control Plan: 1. Introduction: Second Paragraph/Second Sentence - add theTown of Clarkdale to the list of observations of dust.

UVSP Response



Appendix A – Fugitive Dust Control Plan: 3. References: add the following language to the second bulletpoint: as amended by Ordinance #371

UVSP Response




The Town requests incorporating provisions for stationary dust sampling stations to be placed up- anddownwind from the larger work areas to confirm dust control measures are adequate.

UVSP Response

The UVSP does not plan to utilize stationary dust sampling stations in favor of personal air monitoring andvisual indicators of dust control. Stationary dust sampling stations require constant monitoring for properplacement for wind direction and the potential for missed alarm notices. Freeport has found that usingvisual indicators with follow-up personal air monitoring is more effective than stationary stations.

Comment #TOC.64 [TOPIC – REPOSITORY/ESSA]

Appendix B – Excavated Soil Staging Area Operations Plan: The Town of Clarkdale has concerns aboutthe proposed location for the staging area. The area is immediately adjacent to property within the Townof Clarkdale which has a zoning entitlement for Verde Valley Ranch, a proposed mixed-use developmentwith 900 residential units. The subject property is under the administration of Yavapai County and zonedfor single-family development.

UVSP Response

The proposed ESSA area is located outside the Town’s jurisdiction. If the final ESSA and repository arelocated within the Town, appropriate zoning will be obtained.


An Aquifer Protection Permit (APP) must be obtained to own or operate a facility that discharges apollutant either directly to an aquifer, to the land surface, or the vadose zone in such a manner that thereis a reasonable probability that the pollutant will reach an aquifer. The ESSA is within a few hundred feetof the Tavasci Marsh, a component of the Verde River system. As such, groundwater is expected to beshallow, possibly within a few feet of the bottom of the currently existing lined "pond" that was designedand constructed in the past for a different purpose. It is reasonably probable that metals or soil containingelevated concentrations of metals will impact the shallow aquifer, Tavasci Marsh, and Verde River. Thereare numerous requirements specified in the APP program, however, special attention should be paid tothe following items: 1) Best Available Demonstrated Control Technology (BADCT, pronounced "bad cat").Freeport must show that the best demonstrated control technology will be used by the facility. 2) Freeportmust show that Aquifer Water Quality Standards (AWQS) will not be exceeded in the aquifer at the pointof compliance as a result of discharge from the facility. If the level of a pollutant in the aquifer alreadyexceeds the A WQS at the time of permit issuance, the aquifer must not be further degraded as a result ofthe discharge. 3) Freeport must show that they have the financial and technical capability to operate inaccordance with the permit. In most cases, individual permits are issued for the operational life of thefacility. That said, Freeport must demonstrate that using the existing lined retention pond to containimpacted soil will be compliant with the APP program and be the most appropriate BADCT as described inthis RAWP.

UVSP Response

For the same reasons responding to comment [#ADEQ.GENERAL.2], any soil that is placed in the SR willmeet the exemption for “inert material,” or be treated to meet that exemption pursuant to the approved


RAWP. Similarly, the ESSA will be subject to the terms of the approved RAWP and will not be considereda discharging facility under the APP program. Therefore, APP requirements will not be applicable to theESSA or SR.


Appendix B, Figure B-1: This figure shows the locations for the ESSA and the Soil Repository Locations.Has Freeport evaluated if there any jurisdictional waters of the United States regulated by the CleanWater Act or the Clean Water Rule? In addition, has Freeport evaluated the actions associated with thisRAWP that may trigger any evaluation under the Nation Environmental Policy Act?

UVSP Response

No jurisdictional waters are present at the location proposed in the RAWP for the ESSA and SR. Thelocations of the proposed ESSA and SR are not located within a jurisdictional “water of the United States,”and will not require federal permit approval. Instead, ADEQ will be the approving authority for the RAWP,and Yavapai County will be the approving authority for a conditional use permit. NEPA will not betriggered by the proposed use of the location for the ESSA and SR. Therefore, aside from the ADEQ’sAZPDES Stormwater Construction General Permit, the requirements of the Clean Water Act and NationalEnvironmental Policy Act referenced in the comment are not relevant to the proposed location of theESSA and SR.


Appendix B, Section 2.1.2 – Erosion Control: Erosion control measures should be maintained in perpetuityaround the Soil Repository, not just around the ESSA during the duration of the Soil Program cleanupactivities. This would likely be required by the APP program which Freeport should be required toimplement as it relates to this RAWP.

UVSP Response

For the same reasons responding to comments [#ADEQ.GENERAL.2 and #TOC.65], the ESSA and SRwill not be subject to APP requirements. In brief, an APP is not required for the UVSP ESSA and SRlocation. Once the UVSP has been completed, the SR will be capped and monitored to ensure erosion iscontrolled.


Appendix B, Section 2.2.1 - Movement of Material within the ESSA: 6 inches of suitable aggregate placedon top of a geotextile fabric should be considered the minimum control to minimize tracking soil, dust, ormud onto public right-of-ways. Freeport should also be required to make provisions for street sweepersand exit grids if the minimum control fails to contain soil within the ESSA. This would likely be required bythe APP program which Freeport should be required to implement as it relates to this RAWP.

UVSP Response




Appendix B, Section 2.2.2 - Initial Material Segregation and Soil Characterization: Describes the numbersof grab samples to be collected from each stockpile and is reasonable as long as each pile is no greaterthan 1,000 cubic yards and each grab sample is collected from approximately equally spaced locations onand within the stockpile. Because potentially "Characteristic Hazardous Waste" should not be transportedto the ESSA for sampling, profiling, and treatment because many provisions of RCRA could be violated,smaller soil stock piles should be created and managed at each individual property; therefore, limiting thesize of each stockpile making the stockpile sampling plan reasonable.

UVSP Response

For the same reasons stated in the response to comment [#ADEQ.GENERAL.2], management of soilwithin the AOC will not involve “hazardous waste” regulation.

In brief, the AOC Policy allows transport of soil to the ESSA for testing and treatment under RCRA.Managing small stockpiles on every property creates an unsafe condition for property owners (trip, slip,and fall) which the AOC Policy was intended to address and avoid.


Appendix B, Section 2.2.3 - Soil Management, Treatment and Storage: This Section says "FMCunderstands that management of excavated soil within the ESSA will be on a temporary basis, and soilmay only be managed at this location for a maximum of one year from the time the soil was first placed inthe ESSA until the soils can be placed into the Soil Repository". As described above, no"Characteristically Hazardous Waste" should be transported to the ESSA unless the proper permits are inplace. Additionally, Freeport should describe how it will comply with State law relating to handling andmanaging non-hazardous waste at this location.

UVSP Response

For the same reasons stated in response to comment [#ADEQ.GENERAL.2], the management ofimpacted soil within the AOC will not trigger requirements typically associated with “solid waste” or“hazardous waste” regulation under RCRA, based on the AOC Policy as well as specific Arizonaexemptions to the definition of “solid waste.”

See also the response to #TOC.69


Appendix B, Section 2.2.5 - ESSA Decommissioning: This Section repeatedly references "site-specificcleanup levels (CLs) for commercial land use". To our knowledge, there is no site-specific cleanup levelassociated with the UVSP for "commercial land use".

UVSP Response

The RAWP will be revised to use “non-residential” in lieu of “commercial”.



Appendix B, Section 2.2.5.1 – Sampling: This Section says "Each of the working areas of the ESSA ... willbe divided into 5, 000 square foot grids and sampled for arsenic, copper, lead, tin, zinc and boron. Eachgrid will be sampled by collecting nine equally-spaced grab samples from within the grid. " ThisSection goes on and says "If laboratory analytical results for a given grid are below the site-specificcleanup levels (CLs) for commercial land use, the soils within the grid will be eligible to remain in place orbe used as restoration material (e.g., soil associated with storm water diversion berms)." Immediatelyadjacent to the proposed ESSA, and lying only 100 feet from the Soil Repository, lies property that has anapproved Development Agreement for a mixed use Planned Area Development in the Town of Clarkdale.That said, sometime in the future this immediately adjacent property may be residentially developed andResidential CLs should be used, not "Commercial" (Non-Residential) CLs to determine if remediation isrequired at the ESSA or if the soil is eligible to remain in place. In addition, if Freeport is compliant with theAPP and implements a proper Storm Water Pollution Prevention Plan (SWPPP), using soil that exceedsthe Residential CLs cannot and should not be used as "restoration material" because impacts would likelybe spread to nearby sensitive habitats and surface waters.

UVSP Response

The RAWP will be revised to remove “…or be used as restoration material (e.g., soil associated withstorm water diversion berms)."


Appendix B, Section 2.3 - Storm Water Management: This Section seems to infer that storm watercontrols will be in place and managed only during the Soil Program. Freeport needs to make it clear that acompliant SWPPP will be developed and implemented in perpetuity to prevent erosion or water runofffrom the Soil Repository. This is most important because there is a surface-water body and a sensitivemarsh nearby that could receive eroded and possibly contaminated soil or water. This would likely berequired by the APP and SWPPP programs which Freeport should be required to implement as theyrelate to this RAWP.

UVSP Response

Appendix B refers to the ESSA Operations Plan. The ESSA will be decommissioned at the conclusion ofthe UVSP. Storm water management for the Soil Repository is discussed in Section 2.3 of Appendix Cand Appendix D.


Appendix C, Section 2.1.1 – Clearing Grubbing and Grading: Six inches of suitable aggregate placed ontop of a geotextile fabric should be considered the minimum control to minimize tracking soil, dust, or mudonto public right-of-ways. Provisions should also be made for street sweepers and exit grids if theminimum control fails to contain soil within the ESSA.

UVSP Response




Appendix C, Section 2.1.2 – Erosion Control: Erosion control measures should be maintained in perpetuityaround the Soil Repository, not just around the ESSA during the duration of the Soil Program cleanupactivities. This would likely be required by the APP program which Freeport should be required toimplement as it relates to this RAWP.

UVSP Response

Noted.


Appendix C, Section 2.2.4 – Restoration: How will water drain from the lined basin? Will the SoilRepository be capped at ground level, or will there be a mound created at the site?

UVSP Response



Appendix C, Section 2.6 – Long-Term Operation and Maintenance: Section 2.6-Freeport plans to annuallyinspect, more frequently after a heavy rain, document, repair, and submit to ADEQ an annual report. TheTown disagrees that management of this facility should stop after 10 years and Freeport must justify that10-year limit in terms of regulatory programs that should be followed such as the APP and SWPPP.

UVSP Response

For the same reasons stated in the response to comments [#ADEQ.GENERAL.2 and #TOC.65], theESSA and SR will not be subject to APP requirements. The SWPPP will be terminated when the cap isplaced on the SR and construction is completed. Freeport will retain ownership and responsibility for theproperty. A DUER will be recorded with the property records to note the repository location and status.


Appendix C, Section 2.6 – Long-Term Operation and Maintenance: The Section also says "At thecompletion of the UVSP, a declaration of environmental use restriction (DEUR) will be added to theproperty where the soil repository will be located." Freeport should clarify that this DEUR will be preparedand filed at the beginning of the active UVSP, before soil is received by the facility. Additionally, Freeportmust describe their financial assurance plan, compliant with the APP or some other appropriaterequirement.

UVSP Response

A DUER is only required upon completion of the UVSP and is intended to address post-closure land useand care and maintenance.



Appendix C, Section 2.6 – Long-Term Operation and Maintenance: There is no mention that groundwatermonitoring wells will be installed and sampled to confirm that the "soil cap" and "liner" is functioningproperly and that contaminants are not leaching into groundwater. At a minimum, Freeport should justifywhy they do not plan to monitor groundwater. This would likely be required by the APP program whichFreeport should be required to implement as it relates to this RAWP.

UVSP Response

For the same reasons stated in the response to comments [#ADEQ.GENERAL.2 and #TOC.65], the SRwill not be subject to APP requirements. As noted previously, an APP is not required for the SR andtherefore monitoring wells are not necessary.


Appendix C, Section 2.6 – Long-Term Operation and Maintenance: Fourth paragraph/Notation should beadded that the rainfall will be measured at the nearest weather monitoring station at Tuzigoot NationalMonument.

UVSP Response


Comment #TOC.81 [TOPIC – SWPPP]

Appendix D, Section 1 – Introduction: Does Freeport intend to submit the required Notice of Intent (NOI)which is required by the referenced General Permit. If Freeport does not plan to submit a NOI how canFreeport be compliant with the referenced General Permit?

UVSP Response

Yes, a NOI will be submitted.


Appendix D, Section 2 – Regulatory Basis: Freeport should confirm that they will be compliant and followthe most current General Permit and that General Permit will require a SWPPP. Why is Freeport planningto use what appears to be an expired General Permit (AZG2008-001) that may have expired February 28,2013.

UVSP Response

The RAWP will be revised to reference AZG2013-001.



Freeport needs to confirm that the ADEQ Water Quality Division specifically reviews and approves thisplan. It appears that Freeport's Storm Water Management Plan (SWMP) may be deficient and not acompliant Storm Water Pollution Prevention Plan (SWPPP).

UVSP Response

Noted.


Appendix D, Section 3.2 – Erosion Control Measures: This Section says "Erosion control measures will beimplemented for the duration of the voluntary soil cleanup operations in the ESSA, BSA, and SoilRepository." Freeport should clarify if this also means during the active program, the 10-year inspectionperiod, and thereafter.

UVSP Response



Appendix D, Section 4 – Inspection and Maintenance: Reference should be incorporated that themonitoring station at Tuzigoot Monument shall be used so the location accurately reflects rain events atthe Soil Staging Area and Soil Repository.

UVSP Response



This Section says that the storm water management features will be inspected as soon as practicable. IfFreeport plans to implement the referenced General Permit (AZG2008-001) then the permit requires thatan inspection occurs within 24 hours of the end of each rain event of 0.5- inches or greater; not whenpracticable, and not after 3/4 inches of rain. Freeport should develop and implement a SWPPP compliantwith the referenced General Permit or the most current and applicable General Permit.

UVSP Response



Appendix D, Section 5 – Monitoring Program Review and Modification: This Section says that if adischarge occurs, the receiving stream will be sampled. Because this SWMP does not appear to be acomplete SWPPP, discharge conditions and the receiving stream are not acknowledged or described. At


a minimum, Freeport should implement a compliant SWPPP and ensure that there are no discharges toany receiving stream or sensitive habitats.

UVSP Response

Once selected, the contractor providing soil cleanup activities will submit a SWPPP for approval.


RESPONSE TO NATIONAL PARK SERVICE (NPS) COMMENTS

Comment #NPS.1

The RAWP mentions the need for grading and right-of-way permits issued by the Town of Clarkdale aswell as “adherence to permit standards” and consistency with “applicable federal, state, and localrequirements.” Will FMC apply for other permits associated with the removal and transport ofcontaminated soil? Similarly, are there other documents or plans which analyze the potentialenvironmental impacts of the proposed transportation and long-term storage of contaminated soil in moredetail? (In lieu of these documents, [NPS] has the following comments and questions.)

UVSP Response

The UVSP, including activities at the proposed ESSA and SR, will not require federal permitting. First, forthe same reasons responding to comment [#ADEQ.GENERAL.2], the management of impacted soil withinthe AOC will not trigger requirements typically associated with “solid waste” or “hazardous waste”regulation under RCRA, based on the AOC Policy as well as specific Arizona exemptions to the definitionof “solid waste.” Second, the proposed locations for the ESSA and SR are outside the boundaries of theTuzigoot National Monument “system unit” and are privately owned (i.e., the relevant properties have notbeen acquired by the NPS). The NPS only has authority to administer lands that are within a “systemunit,” and is only authorized to regulate “solid waste” activities that occur on property of the United Statesthat is under NPS jurisdiction. Therefore, the NPS’s regulation regarding “solid waste disposal sites” at 36C.F.R. Part 6 is not applicable to the ESSA and SR, and does not raise NPS permitting or approvalrequirements.

Similarly, permits for transportation are not anticipated.

Comment #NPS.2

The RAWP identifies a protocol for soil transportation that states “trucks will follow a direct route usingmajor roadways and avoid neighborhood streets to the extent practicable…truck drivers will be instructedas to the preferred routes between the property, backfill source, and ESSA prior to initiating haulingactivities.” How many trucks will be operating in the area each day?

UVSP Response

Due to the slow nature of soil cleanup activities related to the UVSP, there will not be a great increase invehicle activity. Assuming an average of 1,000 cubic yards shipped to the ESSA per week, there would beon average about 80 loads to the ESSA per week or about one every 30 minutes. Actual numbers willvary depending on activities at the individual property. A Traffic Control Plan will be developed prior toperforming soil removal activities.

Comment #NPS.3

Where is the backfill source?

UVSP Response



Comment #NPS.4

Will FMC be responsible for damage to the road caused by truck traffic?

UVSP Response

FMC will be responsible for damage to the road caused by activities related to the UVSP. The UVSP willperform pre-, post-construction and potential periodic LIDAR testing or equivalent of all roadways to beused by the UVSP.

Comment #NPS.5

What are your technical reasons for saying “The Study Area includes properties most likely to have beenaffected by historical air emissions…”

UVSP Response

Based on historical information from the smelter operations and meteorological information from thePhoenix Cement Plan (Clarkdale on Cement Plant Road), Freeport reasoned that particulate containingmetals from air emissions may have settled within areas of the Town of Clarkdale. The initial Study Areawas located nearest the smelter and included residential areas that were developed at the time of thesmelter operation.

After submitting the draft RAWP, the UVSP submitted an amended Voluntary Remediation ProgramApplication for the UVSP to ADEQ for its approval, including a map of the expanded UVSP Study Area.That transmittal included a Technical Memorandum explaining the analysis conducted by FMC regardingthe expanded UVSP Study Area, based on available sampling results from the UVSP. This TechnicalMemorandum is responsive to this comment. ADEQ approved the expansion of the Study Area on March10, 2017.

Comment #NPS.6

Although the RAWP addresses concerns with traffic-flow in residential neighborhoods, it does not discussthe potential impacts caused by dump trucks on Tuzigoot Road, which is owned by the NPS. TuzigootRoad is a major access route to the Verde River as well as an access route to pedestrian trails on NPS,Arizona State Park, and Forest Service lands. Has FMC considered how increased traffic on TuzigootRoad will impact recreational activities, Arizona State park and NPS operations, visitor enjoyment, and thelocal economy?

UVSP Response

Please see the response to Comment #NPS.2.


Comment #NPS.7

The RAWP also states that “Any materials spilled during transport will be cleaned up and removed assoon as practicable.” To reach the ESSA, trucks must cross over the Verde River via the Tuzigoot Bridge.Does FMC have a more detailed contingency plan for spills that could occur in or around the Verde River?

UVSP Response

UVSP will develop a Contingency Plan prior to conducting soil cleanup activities.

Comment #NPS.8

TUZI contains ancestral Native American sites and historic buildings listed on or eligible for the NationalRegister of Historic Places. These important places interpret human occupation and land use in the VerdeValley and represent the enduring cultures and histories of living Native American people. Depending onthe expected truck and equipment traffic on Tuzigoot Road, FMC operations may have short and/orlong-term visual and auditory impacts to these properties. Similarly, the use of trucks and heavyequipment will also have negative impacts to visitor experience in and around TUZI. More information onthe number of trucks and the expected duration of the project would be helpful for assessing andunderstanding these impacts in more detail.

UVSP Response

Please see the response to Comment #NPS.2. Soil cleanup activities are estimated to last from one tothree years depending on owner participation, production rates, etc.

Comment #NPS.9

Appendix A: Dust Control Measures, proposes several techniques to minimize fugitive dust generationfrom proposed excavation and treatment activities. For activities on FMC land, Peck’s Lake is identified asa primary water source for controlling fugitive dust. Water removal has the potential to disturb lakesediments, which reportedly contain metal contaminants. Project activities have the potential to disturbthese sediments, which could then be flushed into Tavasci Marsh. Although the RAWP describes waterquality testing for dust control using Peck’s Lake water, how will FMC avoid disturbing lake sediments?

UVSP Response

The contractors associated with activities related to the UVSP will utilize techniques such as a floatingpump station to prevent disturbance of the sediment when extracting water from Peck’s Lake.

Comment #NPS.10

Appendix B: Excavated Soil Staging Area Operations Plan identifies a location and techniques for storing,testing, and treating contaminated soils. TUZI is particularly concerned with the proposed location forthese activities because it is within a few hundred feet of the Tavasci Marsh, an important component ofthe Verde River system. This area is also subject to seasonal flooding, particularly during the SummerMonsoon. The development of the ESSA, as defined in the RAWP includes the construction of a bermand the creation of concrete pads and a work area, in part, to control flooding, erosion, and the transport


of contaminated soil into the marsh. Has FMC considered the potential environmental impacts oflarge-scale ground disturbance in and around the Tavasci Marsh?

UVSP Response

Yes. The proposed ESSA and SR will be subject to a SWPPP that will prevent any surface dischargesfrom the area. Dust control measures will be implemented as described in Section 3.1.7 and Appendix Aof the RAWP to mitigate air dispersion of soil from the area. Further, the soil form the UVSP will betested (and if necessary treated) to ensure that it is insert and will not leach metals in excess of federalaquifer protection standards.

Freeport will apply dust control measures and stormwater controls as required by a SWPP so as not toimpact Tavasci Marsh. The soil placed in the SR will not be leachable as to impact groundwater in thearea.

Comment #NPS.11

We understand that the use of Toxicity Characteristic Leaching Procedure (TCLP) and SyntheticPrecipitation Leaching Procedure (SPLP) analysis is needed to characterize soils and determine finalstorage locations for contaminated soils. It is unclear what long-term measures will be taken to managesoil with testing results below the regulatory thresholds identified in the RAWP.

UVSP Response

Please see the response to comment #TOC.44.

Comment #NPS.12

We also understand that decommissioning the ESSA will follow extensive soil testing. Does FMC havebaseline data on arsenic, copper, lead, and other heavy metals that may already be present in soil fromthis area? If so, how do these levels compare with the regulatory thresholds identified in the RAWP?

UVSP Response

Baseline data has not been collected or analyzed at this time.

Comment #NPS.13

Soil removed from Clarkdale contains seeds of invasive plant species including but not limited to tree ofheaven (Ailanthus altissima), periwinkle (Vinca major), and Russian thistle (Salsola tragus). Thetransportation and storage of soils containing invasive seeds will spread these plants into new areasaround Tavasci Marsh. The close proximity of the ESSA to the TUZI boundary would mean that theburden to control these invasive plants, as they spread into NPS land, would become the responsibility ofthe NPS. Does FMC have an invasive plant management strategy for preventing the spread of invasiveplants in the ESSA? If so, is a copy of this strategy available for NPS review?

UVSP Response

See response to comment #NPS.10 regarding measures that will be used to prevent air dispersion of soilfrom the area. In brief, the soil will be placed in the SR and capped. Spread of invasive plants throughwind-blown seed propagation will be controlled during ESSA operation by dust control methods.


Comment #NPS.14

Appendix C: Soil Repository Operations Plan addresses the long-term operation and maintenance of theESSA and Soil Repository. This includes a proposed annual monitoring and reporting period of ten years.Will copies of these annual reports be provided to the general public and the NPS? What happens afterthe ten year period?

UVSP Response

All soil will be removed from the ESSA and it will not be subject to any long-term operation andmaintenance. The SR will be subject to a DUER that will require long-term use restrictions and operationand maintenance.

Freeport will retain ownership of the property and the DEUR will be recorded with the property records.

Comment #NPS.15

Appendix C identifies monitoring following unplanned events such as fires, floods, heavy rains, andseismic events. If contaminants linked to historic smelter operations or the proposed soil remediationprogram are discovered in Tavasci Marsh, will FMC take responsibility for coordinating and implementingclean-up efforts on NPS land?

UVSP Response

This comment is not relevant to the UVSP.

Comment #NPS.16

Appendix C identifies a monitoring program following storm water discharge events. Appendix C statesthat storm water discharge will be “infrequent”. Does FMC have long-term data that indicates theinfrequent nature of discharge events?

UVSP Response

See response to comment #ADEQ.Specfic.5 regarding past stormwater events in the area.

In brief, the SR will be capped after UVSP completion and will be subject to requirements of a SWPPPduring the program.

Comment #NPS.17

Similarly, the plan states that, “the receiving stream will be sampled up-gradient and down-gradient of thedischarge”. Considering the proposed ESSA and Soil Repository location, it is unclear what this sentencerefers to. Presumably, “the stream” refers to Tavasci Marsh. Will FMC contact NPS in the event thatsampling is required?

UVSP Response

Noted. This reference will be deleted as the SWPPP measures will require all stormwater to be collectedwithin the ESSA and not discharged.


Comment #NPS.18

It is also unclear whether the proposed sampling targets water, sediment, or soil. How will specificsampling locations be chosen? If soil sampling occurs, how deep will samples be taken? A recent USGSstudy found copper, arsenic, and other heavy metals within marsh sediments. If FMC proposes to samplesoil, how will new contamination be distinguished from existing heavy metals? Will this information beshared with NPS and the public?

UVSP Response

The UVSP is a residential remediation program and intended to address residential and public use areasin the Town of Clarkdale.


RESPONSES TO YAVAPAI COUNTY (YP) COMMENTS

Comment #YP.1

Yavapai County has strong objections to this proposal. There is no reference to how long the soils will bestored on the property and there does not appear to be a plan for mitigation of same. The property iszoned residential and as such storage of soils on the parcel will be deemed a violation of our codes andabatement measures will be taken.

UVSP Response

UVSP will obtain conditional use permits from Yavapai County prior to any activity being conducted oncounty property. UVSP and Yavapai County have met (April 2017) to discuss the project and answerquestions.


RESPONSES TO GENEVA SAINT-AMOUR (GSA) COMMENTS

Comment #GSA.1

Page 13 – Scheduling of Cleanup: Tier 1, 2 and 3 all reference the cleanup plan for properties with lead.No reference is made to the other materials being tested for. So no plan is stated for properties witharsenic et al? That seemed to be the prevalent toxicity in the target zone.

UVSP Response

The prioritization of cleanup for lead typically uses the Tiered approach. Arsenic results are not planned touse a tiered approach for prioritization.

Comment #GSA.2

Page 6 – Setbacks: Within the root line of a tree is a setback? The number of old-growth mesquites onand near my property have a network of root lines that is quite extensive! That may preclude any earthremoval in the areas of high concentration of arsenic (as per the document mailed to me after sampling).Yet, the area under those trees is also the most undisturbed parts of my property- and therefor where thearsenic has settled and laid on the soil for all these years.

UVSP Response

Setbacks will be used to prevent damages to trees, roads, sidewalks, structures and other improvementson the property. The intent of the UVSP is to remove soil within a use area so that the averageconcentration within the area is below applicable soil remediation levels. This allows impacted soil to beleft within limited setbacks. UVSP personnel will meet with individual property owners to discuss the soilsampling results and an individual cleanup work plan. Questions about property-specific conditions (liketrees) can be addressed at that time.

Comment #GSA.3

Backfill soil: I am unable to find a diagram or description of where the replacement soil (backfill) will becoming from. I can see (page 9) that it will be tested and also where it will be stored. But there is noinformation as to its origin.

UVSP Response


Comment #GSA.4

Location of soil repository: This area seems to be very near the Verde River and Pecks Lake area. Both ofwhich are critical to the underground water source for residents in this area. The plan indicates that the


soil will be tested there and then determinations will be made….. but it never says what happens afterthat. Where does the soil go that does NOT meet the analysis discussed at the bottom of page 11?

UVSP Response

Stockpiles will not be moved from the ESSA to the Soil Repository until treatment has been determined tobe successful by showing the analytical results to be under the TCLP and SPLP criteria.

GHD 7560 N La Cholla Blvd Tucson, Arizona 85741 USA T 520 623 9221 F 520 623 3065

July 12, 2018 Reference No. 11102656 Mr. John Patricki Arizona Department of Environmental Quality Voluntary Remediation Program 1110 W Washington St. Phoenix, Arizona 8500 Dear Mr. Patricki: Re: Remedial Action Work Plan – DRAFT Revision 1

Voluntary Remediation Program United Verde Soil Program Clarkdale, Arizona VRP Site Code: 512101-00

1. Introduction

GHD Services, Inc. (GHD), on behalf of Freeport Minerals Corporation (FMC), is providing this Revision 1

to the Remedial Action Work Plan (RAWP), United Verde Soil Program (UVSP), Clarkdale, Arizona

(approved January 25, 2018). The UVSP has been approved by the Arizona Department of Environmental

Quality (ADEQ) to conduct remediation under ADEQ’s voluntary remediation program (VRP). As such,

the enclosed Draft RAWP Revision 1 is subject to review and approval under the VRP by ADEQ.

In general, this Draft RAWP Revision 1 proposes to modify the design of the Soil Repository Area at the

previously approved “Sycamore Canyon” location as follows:

• Install a high-density polyethylene (HDPE) geomembrane liner system between the prepared

subgrade and excavated soil received from UVSP participating properties;

• Eliminate the former interim soil management protocols associated with the Excavated Soil

Staging Area (ESSA);

• Transport excavated soils from UVSP participating properties directly to the lined Soil Repository

for long-term management; and

• Install a minimum 24-inch thick soil cover system over the excavated soils placed in the lined Soil

Repository

2. Soil Repository Design Components

The Soil Repository Area will serve to consolidate and manage soils from within the Area of

Contamination (AOC). Management of soil at the Soil Repository Area is subject to several specific

exemptions under Arizona and federal law. Facilities that engage in “storage, treatment or disposal of inert

material,” or in “remedial actions” approved under applicable state law, are not required to obtain an

Draft UVSP RAWP Rev 1 Transmittal Letter 2

Aquifer Protection Permit (APP) or solid waste facility approval (A.R.S. §§ 49-250.B.18, 49-250.B.20, 49-

701.15, 49-701.01.B.12, 49-701.01.B.17). Similarly, under A.R.S §§ 49-241 through 49-252, an APP is

only required if a facility discharges a pollutant either directly to a groundwater aquifer, to the land surface,

or the subsurface vadose zone in such a manner that there is reasonable probability that the pollutant will

reach the aquifer.

Despite the applicability of these exemptions, FMC proposes to design the Soil Repository Area under the

VRP such that it will comply with the design requirements outlined in Part 2.5 of ADEQ’s Arizona Mining

Guidance Manual, Best Available Demonstrated Control Technology (BADCT) (ADEQ Pub. No. TB-04-01)

for tailing impoundments. Standards, considerations, and criteria for the design of the Soil Repository

Area are shown in Section 3.2 of the Draft RAWP Revision 1 provided with this submittal package.

3. RAWP Revisions

The Draft RAWP Revision 1 is included as an attachment to this letter. The main text has been redlined

to facilitate focused review. Appendices have been modified as outlined below:

• Appendix D (Excavated Soil Staging Area) has been removed

• Appendix E (this Appendix will now become Appendix D) – includes the Soil Repository design

and the basis for the design

Should you have any questions or comments regarding this draft document, please feel free to contact

Alicia Voss at (602) 316-5467 or myself at (520) 460-6335 or via email at [email protected].

Sincerely,

GHD

Charles Janson

CJ/trc/Patr-002

Encl.

cc: Alicia C. Voss, Freeport Minerals Corporation


Appendix B Example AR/COC Form

Appendix B Fugitive Dust Control Plan

GHD | Remedial Action Work Plan – Revision 1 | Appendix B | 11102656 (4) | Page i

Table of Contents

1. Introduction ................................................................................................................................... 1

2. Dust Control Measures................................................................................................................. 1

3. References ................................................................................................................................... 2

GHD | Remedial Action Work Plan – Revision 1 | Appendix B | 11102656 (4) | Page ii

List of Acronyms

CC Construction Contractor

CPC Construction Project Coordinator


OSHA Occupational Safety and Health Administration



GHD | Remedial Action Work Plan – Revision 1 | Appendix B | 11102656 (4) | Page 1

1. Introduction

This document presents the Fugitive Dust Control Plan for the soil cleanup activities associated with

the United Verde Soil Program (UVSP) in Clarkdale, Arizona. This plan establishes the procedures

to be implemented in order to control potential worksite contaminants from impacting public and

worker safety. This plan supports and is an appendix to the Remedial Action Work Plan (RAWP).

During the course of cleanup activities, the operation of earth moving equipment and vehicles in

work areas may cause the generation of dust, particularly in dry and windy weather conditions. Dust

control measures will be implemented as a routine measure during the work activities to protect

nearby residents and workers from unacceptable levels of dust and lead particulate. Upon visual

observations of dust by the Construction Project Coordinator (CPC), the CPC’s designee, the

Construction Contractor (CC), and the Town of Clarkdale additional dust control measures will be

immediately implemented.

The effectiveness of dust control measures will also be confirmed by using personal worker

monitors. The monitors directly measure total dust and metals, which can be compared to

appropriate 8-hour time-weighted average Occupational Safety and Health Administration (OSHA)

occupational exposure limits. Dust control measures may include wetting of soil, slowing work

activities, and other designated methods specified in the RAWP.

2. Dust Control Measures

This section outlines the dust control practices that will be followed during project activities. Controls

will be implemented to minimize fugitive dust generation from excavation activities. Visual

observations will be used to evaluate the effectiveness of the controls.

Dust control measures will be a high priority for project personnel. Dust control will be achieved

primarily by watering down work areas and vehicle traffic routes. According to Section 7-11-12 Part

Q of the Town Code of the Town of Clarkdale, either a dust palliative or reclaimed water shall be

used for the alleviation or prevention of dust. Use of fresh water for dust control is prohibited.

The water source for dust suppression will be from Peck’s Lake located on Freeport Minerals

Corporation (FMC) property or from a reclaimed water source. Each water source will need to be

sampled and analyzed for UVSP target constituents per the Quality Assurance Project Plan (GHD,

2015) prior to use. Watering at properties undergoing soil excavation and at soil stockpiles and haul

roads within the Soil Repository will be provided on an as-needed basis, as follows:

During soil excavation activities (by heavy equipment and by hand crews),

During stockpiling and/or loading of soils for transport,

During soil backfill activities, and

Wetting down truck loads to control visible emissions during transport (truck loads will also be

covered when traveling public roads).

GHD | Remedial Action Work Plan – Revision 1 | Appendix B | 11102656 (4) | Page 2

Additional dust control measures will be aggressively implemented under windy

conditions (measured wind speed greater than 10 miles per hour), whenever dust plumes are

observed leaving an active soil excavation or the Soil Repository, or as needed based on real-time

soil particulate measurements. Dust-generating activities will be stopped when sustained wind

speeds exceed 25 miles per hour.

Dust control actions will primarily include application of water sprays to restrict dust generation in

vehicle traffic routes (via water truck spray bars) and work areas (via hose/spray system fed from a

portable water tank). Soil stockpiles may be covered during non-work hours or will be moistened

using the side-bar sprayer on a water truck or hose/spray system fed from a water truck. In

instances where application of water spray is not sufficient to prevent generation of visible dust,

other dust control measures that may be used are as follows:

Increased frequency of water spray applications,

Regulation of vehicle speed,

Placement of additional clean gravel as a ground cover in high dust generation areas,

Application of surfactant, or

Other appropriate measures.

Care will be taken to avoid application of excessive amounts of water that may cause unacceptable

working conditions or increase the possibility of surface water run-off. If additional dust control

measures do not eliminate visible dust or result in action levels being met, construction activities will

be temporarily suspended until additional dust control measures have been implemented, or until

adverse weather conditions abate. Dust control alternatives may be re-evaluated on an as-needed

basis.

3. References

GHD, 2015. Quality Assurance Project Plan, United Verde Soil Program,

Clarkdale, Arizona, July

Town of Clarkdale, Town Code of the Town of Clarkdale, Arizona, Chapter 7: Building, as

amended by Ordinance #371.


Appendix A Title

Appendix C Sampling Data to Support Soil Repository

Location

!( !(

!(

!(!(

V e r d e R i v e r

400-01-002B-SR004 400-01-002B-SR005

400-01-002B-SR003

400-01-002B-SR002400-01-002B-SR001

SYCAMORE CANYON RD

Revis

ed By

File N

ame:

CLARKDALE, ARIZONA

Figure C-1SYCAMORE CANYON SOIL REPOSITORY

BASELINE SAMPLING

11/15

/2017

Water

looRM


Legend!( Sample Location

Parcel Boundary

TOWN OF CLARKDALE

1110

2656

(RAW

P)GI

S_WA

_005

Offic

e


Table C-1Analytical Results for the Sycamore Canyon Soil Repository

Remedial Action Work PlanVoluntary Remediation Program

United Verde Soil ProgramClarkdale, Arizona

Page 1 of 1

Arsenic Boron Copper Lead Tin Zinc

Yavapai County Parcel Number

Sample ID Collection Date

Depth BGS (inches)

Sample

Purpose1

30 ppm

16,000 ppm

9,000 ppm

425 ppm

47,000 ppm

23,000 ppm

400-01-002B 400-01-002B-SR001-AC-C0001 10/31/2017 0 - 3 REG 39 3.70 J 487 207 ND(24.1) 269400-01-002B 400-01-002B-SR002-AC-C0002 10/31/2017 0 - 3 REG 25.9 4.36 J 351 126 ND(24.1) 209400-01-002B 400-01-002B-SR003-AC-C0003 10/31/2017 0 - 3 REG 20.5 4.30 J 317 121 ND(24.6) 199400-01-002B 400-01-002B-SR004-AC-C0004 10/31/2017 0 - 3 REG 32.7 4.09 J 502 142 ND(24.3) 237400-01-002B 400-01-002B-SR005-AC-C0005 10/31/2017 0 - 3 REG 39.2 6.4 652 196 ND(24.5) 336

Abbreviations:

BGS: below ground surface

J: Estimated concentration

ND: Not detected at the associated reporting limit

ppm: parts per million

1 Sample Purpose Nomenclature

REG: Regular

Cleanup Level for Residential Properties (A bold result indicates a concentration above the cleanup

level)

GHD | Freeport Minerals Corporation - Remedial Action Work Plan | Appendix C |11102656 (4)


Appendix A Title

Appendix D Soil Repository Design, Construction and

Operations Plan

GHD | Freeport Minerals Corporation - Remedial Action Work Plan – Revision 1| Appendix D | 11102656 (4) | Page i

Table of Contents

1. Introduction ................................................................................................................................... 1

2. Site Work ...................................................................................................................................... 2

2.1 Preparing the Soil Repository Area ................................................................................... 2

2.1.1 Clearing, Grubbing and Grading ....................................................................... 2 2.1.2 Erosion Control ................................................................................................. 3 2.1.3 Dust Control ...................................................................................................... 3 2.1.4 Security ............................................................................................................. 3

2.2 Soil Repository Construction.............................................................................................. 3

2.2.1 Clearing, Grubbing and Grading ....................................................................... 3 2.2.2 Stormwater Controls ......................................................................................... 3 2.2.3 Bottom Liner System ........................................................................................ 4

3. Soil Repository Fill Plan and Operations...................................................................................... 5

3.1 Equipment Decontamination .............................................................................................. 5

3.2 Slope Stability Analysis ...................................................................................................... 6

4. Soil Repository Final Cover Design ............................................................................................. 6

4.1 Final Cover/Cap ................................................................................................................. 6

4.2 Post-Closure Stormwater Controls .................................................................................... 6

5. Reporting ...................................................................................................................................... 6

6. Long-Term Operation and Maintenance ...................................................................................... 7

Figure Index D-1 Pre-Construction Site Plan

D-2 Bottom Liner Site Plan

D-3 Final Cover Site Plan

D-4 Soil Repository Details

GHD | Freeport Minerals Corporation - Remedial Action Work Plan – Revision 1| Appendix D | 11102656 (4) | Page ii

List of Acronyms

ADEQ Arizona Department of Environmental Quality

AOC Area of Contamination

APP Aquifer Protection Permit

ARS Arizona Revised Statute

BADCT Best Available Demonstrated Control Technology

CFR Code of Federal Regulations

CGP Construction General Permit

CY Cubic Yards

DEUR Declaration of Environmental Use Restriction

HDPE High-density polyethylene

HELP Hydrologic Evaluation of Landfill Performance


FS Factor of Safety


SWPPP Stormwater Pollution Prevention Plan

TC Target Constituent(s)


GHD | Freeport Minerals Corporation - Remedial Action Work Plan – Revision 1| Appendix D | 11102656 (4) | Page 1

1. IntroductionThis document presents the Soil Repository Area design, construction and operations plan for the cleanup activities associated with the United Verde Soil Program (UVSP) in Clarkdale, Arizona. This project is being conducted under the Voluntary Remedial Program (VRP) that can be found under Arizona Revised Statutes (A.R.S.) § 49-171 through § 49-188. This plan establishes the procedures to be implemented and documented to construct the Soil Repository Area and to manage the excavated soils, which will be managed within the Soil Repository. The excavated soils will be generated as a result of property soil remediation activities that will be conducted as part of the UVSP

within the Study Area over the next several year(s). This Soil Repository Design, Construction and

Operations Plan supports and is an appendix to Revision 1 of the Remedial Action Work Plan (RAWP).

The Soil Repository Area is located approximately one mile north of Clarkdale just outside the Town of Clarkdale limits on Freeport Minerals Corporation (FMC) property and within the Area of Contamination (AOC) for the former smelter as shown on Figures1 and 2. GHD collected soil samples from the Soil Repository Area to document the extent of the AOC. The Soil Repository Area

is located within the AOC. The Soil Repository is an approved VRP activity and is not required to

obtain an Aquifer Protection Permit (APP) or solid waste facility approval under A.R.S. §§ 49-

250.B.18, 49-250.B.20, 49-701.15, 49-701.01.B.12, 49-701.01.B.17 (as previously documented during the notice, comment, and approval processes for UVSP work plans).

The Soil Repository Area will be an approximately 15-acre area surrounded by a locking security

fence and will consist of the following components:

Access road from Sycamore Canyon Road to the Soil Repository Area;

An Equipment Storage Area;

A zero-discharge Stormwater Containment Basin and other stormwater control features; and

A Soil Repository to serve as the final resting place for soils generated from the UVSP

excavation activities.

The Soil Repository will consist of a lined and capped facility. The soil cap will support vegetation to

minimize seepage through the cover. The proposed design incorporates design requirements

outlined in Part 2.5 of ADEQ’s Arizona Mining Guidance Manual, Best Available Demonstrated

Control Technology (BADCT) (ADEQ Pub. No. TB-04-01) for tailing impoundments. Standards,

considerations, and criteria for the design of the Soil Repository Area include the following:

Floodplains (BADCT Section 2.5.1.2): Material will not be placed within the 100-year floodplain.

Run-on / run-off control systems (BADCT Section 2.5.1.2): A run-on control channel will be

constructed along the eastern portion of the Soil Repository and sized to convey the 100-year,

24-hour storm event. The Stormwater Containment Basin will be sized to contain the estimated

water volume that results from the 100-year, 24-hour storm event during construction and

closure.

Site preparation (BADCT Section 2.5.2.3 and 2.5.2.4): Site preparation will include clearing the

area of vegetation, grubbing and grading as well as subgrade preparation, which will consist of,


at a minimum, twelve inches of 3/8 inch minus native materials. The soil surface will be

compacted, finished smooth and inspected prior to geosynthetics installation to remove

protruding particles, if present.

Bottom liner (BADCT Section 2.5.2.4): A 60-mil textured high-density polyethylene (HDPE)

geomembrane will be installed as the bottom liner over the prepared subgrade.

Drainage Layer and Collection System (BADCT Section 2.5.2.4): A geocomposite drainage layer

and gravity-fed drainpipe will convey percolation to the Stormwater Containment Basin where

the percolation will ultimately be evaporated into the atmosphere.

Slope Stability (BADCT Section 2.5.2.5): The Soil Repository design and construction will meet

the static and pseudo-static requirements of BADCT.

Cover material and thickness (BADCT Section 1.2.3 and 2.5.4): HELP modeling demonstrates

that average annual total percolation thru a 24-inch cover material is anticipated to be less than

five percent. This is mainly due to the arid climate conditions of the Site.

Public Access Control: A locked security fence will be installed to discourage unauthorized

traffic and uncontrolled dumping.

Groundwater Monitoring: Groundwater was not encountered during the geotechnical

investigation. Groundwater is anticipated to be approximately 50 to 80 feet below the ground

surface of the Soil Repository Area. Groundwater monitoring will not be performed due to the

efficiencies of the top cover and bottom liner system.

2. Site Work

The objective of the Soil Repository Design, Construction and Operations Plan is to identify and

describe the various features of the Soil Repository, along with a description of the procedures

required for handling excavated materials within the Soil Repository.

2.1 Preparing the Soil Repository Area

Prior to beginning operations in the Soil Repository Area, erosion control measures and stormwater

management will be established consistent with the ADEQ-approved Stormwater Pollution

Prevention Plan (SWPPP, AZCN69275 issued December 28, 2017)), which is compliant with

ADEQ’s 2013 Construction General Permit (CGP) and approved by ADEQ prior to the

commencement of construction activities.

2.1.1 Clearing, Grubbing and Grading

Clearing, grubbing, and/or grading will be conducted prior to initiating construction activities in the

Soil Repository Area. Clearing will consist of cutting brush to ground level. Grubbing will consist of

removing stumps, vegetation, and roots three inches in diameter or larger from below ground level.

All materials cleared and grubbed within the Soil Repository Area will be transported off-site to an

authorized disposal facility. Grading will consist of leveling and compacting soils to prepare for the

installation of roads, equipment storage area, Stormwater Containment Basin, and the Soil

Repository.


2.1.2 Erosion Control

The objective of erosion control is to effectively implement erosion and stormwater management

controls to minimize erosion of Soil Repository Area. Essential components of the erosion and

sediment control methods will be installed and will be fully functional before commencement of any

soil disturbance activities. Erosion control measures will be implemented within the Soil Repository

for the duration of the construction activities. The ADEQ-approved SWPPP for the Soil Repository

Area provides additional details related to erosion control requirements.

2.1.3 Dust Control

Water sprinklers or water trucks will be used to control dust during site activities as needed. The

excavated soils delivered into the Soil Repository will be moistened as necessary to control the

generation of fugitive dust during material handling and placement. The Fugitive Dust Control Plan

included in Appendix B of this RAWP presents the detailed procedures for dust control.

2.1.4 Security

The Soil Repository Area lies within an area owned by FMC and will have a perimeter fence with a

lockable entrance gate. The entrance gate will remain locked after operating hours and during

periods of inactivity to prevent unauthorized access. No casual visitors or unauthorized personnel

will be permitted to enter the Soil Repository Area without prior approval.

2.2 Soil Repository Construction

The Soil Repository will serve as the final resting place for excavated soils originating from UVSP

participating property cleanup activities. The Soil Repository construction to prepare for the

reception of excavated soils will consist of the following activities:

Clearing, grubbing and grading

Installation of stormwater controls, and

Construction of the liner system

2.2.1 Clearing, Grubbing and Grading

Clearing and grubbing activities will follow those outlined in Section 2.1.1 above. Grading activities

will include excavating the first one to four feet of soil within the footprint of the Soil Repository,

screening the excavated soil to remove rocks larger than 3/8-inch in diameter. Soil will be re-

installed and compacted within the footprint of the Soil Repository. The subgrade for the Soil

Repository will have a minimum slope of 2 percent.

2.2.2 Stormwater Controls

The Soil Repository has been designed to be a zero-discharge facility; therefore, the Stormwater

Containment Basin and run-on/run-off control channels were designed and will be constructed to contain run-off and provide erosion protection from a 100-year, 24-hour storm event (See Figure D-

2).


A run-on control channel will be constructed along the eastern edge of the Soil Repository prior to

the placement of material within the Soil Repository and remain in place after construction activities

are completed. The east run-on control channel will divert stormwater run-on along the eastern and

southern edges of the Soil Repository and into an existing drainage channel. The existing

topography along the northern edge of the Soil Repository drains away from the Soil Repository

Area; therefore, stormwater run-on structures will not be constructed in this area.

Precipitation run-off that has encountered excavated material within the footprint of the Soil

Repository will ultimately be directed to the Stormwater Containment Basin via the perimeter berm

and percolation collection system. The Stormwater Containment Basin will have a liner integrated with the Soil Repository liner system described in Section 2.2.3. Any collected run-off will be

evaporated. The Stormwater Containment Basin is capable of containing the 100-year, 24-hour

storm event during placement activities (open condition) and a closed condition.

2.2.3 Bottom Liner System

The Soil Repository bottom liner system will consist of a liner between the prepared subgrade and

the excavated soil. The liner system components (from bottom to top) will include:

Subgrade and Perimeter Berm

Geomembrane

Geocomposite Drainage Layer with Percolation Collection System

Protection Layer

2.2.3.1 Subgrade and Perimeter Berm

The subgrade will be prepared as described above in Section 2.2.1. A berm will be constructed

around the Soil Repository footprint to assist with the following:

Convey precipitation run-off from the Soil Repository footprint to the Stormwater Containment

Basin and ultimately prevent run-off from departing the Site

Allow the full encapsulation of excavated soil as the berm ties into the final cover

Allow for the construction of an anchor trench for the bottom liner system components

2.2.3.2 Geomembrane Liner

After preparation of the subgrade and construction of the perimeter berm, a textured 60-mil High-

Density Polyethylene (HDPE) geomembrane will be installed to provide separation between the

native soil and excavated material being placed in the Soil Repository. The 60-mil thickness will

resist some impact from sharp objects and will remain pliable to allow for relative ease of installation.

Care will be taken during placement activities to minimize potential damage to the geomembrane

liner by construction equipment. Inspections of the liner will be conducted and, if necessary, repairs

will be completed prior to final material placement.


2.2.3.3 Geocomposite Drainage Layer with Percolation Collection System

A geocomposite drainage layer will be installed directly above the geomembrane liner. This layer will

convey water generated from precipitation or dust control measures conducted during placement of

excavated soil to a sump for the percolation collection system. A gravity drainpipe will be located at

the sump of the Soil Repository to convey percolated water to the Stormwater Containment Basin.

2.2.3.4 Protection Layer

The protective layer will consist of UVSP excavated soil that has been processed/screened to

remove angular rocks that could potentially damage the 60-mil HDPE liner. A minimum 12-inch

protective layer will be placed over the geomembrane liner prior to allowing placement of

unscreened UVSP excavated soil.

3. Soil Repository Fill Plan and Operations

The Soil Repository will serve as the final resting place for soils generated from the UVSP

excavation activities. The erosion and stormwater management controls described in Section 2

apply to this area. The Soil Repository is designed to store approximately 150,000 CY based on

anticipated excavation quantities generated from the cleanup effort. These soils are anticipated to

arrive at the Soil Repository at a frequency of 750 to 1,000 cubic yards per week over the estimated

three to five-year duration of the UVSP.

The excavated soil will be delivered to the Soil Repository, unloaded, and then spread in lifts and

compacted with earthmoving equipment. Grading will maintain positive drainage to minimize

ponding and facilitate flow to the Stormwater Containment Basin. The excavated soil will be placed

in the bottom of the Soil Repository and filled against the active face in a wedge to minimize the

work zone. A minimal working face/zone will assist in reducing the water consumed for dust control

measures and reduce the exposure of impacted material to precipitation.

3.1 Equipment Decontamination

An equipment decontamination pad will be constructed in order to reduce the possible transport of

mud by motor vehicles. All visible soil will be removed from vehicles and equipment prior to exiting

the Soil Repository. Decontamination will first involve a brush down of equipment in the designated

decontamination area to remove visible accumulations of soil from machinery, tires, and shovels,

etc. Use of water will be avoided whenever possible, and will only be used if visible amounts of soil

are evident after dry brushing. In these cases, equipment will be washed on the equipment

decontamination pad to minimize the migration of mud and water. Material removed during

equipment decontamination will be contained and placed in the Soil Repository.

Access ways will extend from the public access road to at least the exit point of the equipment

decontamination pad. Soil or mud tracked onto Sycamore Canyon Road will be removed each day

via street sweeper or other equipment.


3.2 Slope Stability Analysis

A slope stability analysis was performed to assess the safety of the Soil Repository by estimating the

resistance of the side slopes to failure by sliding or collapsing. To assist in the analyses, a

geotechnical investigation was conducted March 25, 2018 in order to determine the subsurface and

groundwater conditions at the Soil Repository site. Seven test pits were advanced to a depth of 10

feet or shallower if bedrock was encountered. Soil samples were collected to determine the bulk

densities, shear strength and other geotechnical parameters for the materials involved. Groundwater

was not encountered during the investigation; it is likely under the influence of the Verde River and is

expected to be approximately 50 to 80 feet below ground surface.

A factor of safety (FS) in slope stability analysis can be defined as the ratio of the available shear

strength to that of the applied stresses along a potential failure plane. A factor of safety of one or

greater indicates stable conditions and a value of less than one represents unstable conditions. A

value of 1.5 was targeted for the static analyses, and 1.1 for pseudo-static (seismic) analyses.

4. Soil Repository Final Cover Design

The primary purposes of the engineered cover system is to isolate the underlying excavated soil

from the environment and reduce infiltration through the Soil Repository. The final cover system is

designed to minimize erosion and minimize precipitation from infiltrating and coming into contact

with the excavated soil, thereby limiting the volume of seepage to the liner system.

4.1 Final Cover/Cap

The final cover/cap will be a 2-foot thick layer of soil capable of supporting vegetation. A Hydrologic

Evaluation of Landfill Performance (HELP) model was run for a 24-inch layer of cover soil. The

HELP model demonstrates the final cover system has an overall efficiency of over 95 percent. The

cap will be graded to ensure positive drainage and seeded with native grasses.

4.2 Post-Closure Stormwater Controls

The surface of the Soil Repository will be graded to direct run-off toward a down chute and ultimately

to the Stormwater Containment Basin. Any surface water or water percolating from the Soil

Repository will be directed to the Stormwater Containment Basin where the water will be collected

and evaporated. The east run-on control channel will remain in place to divert up-gradient surface

water around and away from the Soil Repository.

5. Reporting

Information related to the construction activities will be prepared and submitted with the UVSP final

completion report as outlined in Section 5.3 of the RAWP. The information will include at a minimum:

Initial and final topographic survey (as-built) information.

Construction inspection records.


6. Long-Term Operation and Maintenance

Upon completion of the site activities and after restoration of the Soil Repository, FMC will apply to

ADEQ to make a declaration of environmental use restriction (DEUR) at the Soil Repository. The

DEUR will utilize land use restrictions and applicable engineering controls (cap, fence, etc.) as

necessary to protect public health and the environment. The DEUR, is a restrictive covenant that

runs with the land and will be in effect in perpetuity, unless terminated at ADEQ’s approval. The

DEUR application will include long-term monitoring and maintenance of all engineering controls.

FMC will be responsible for maintenance of the engineering controls and submitting annual

inspection reports to

GHD | Freeport Minerals Corporation - Remedial Action Work Plan – Revision 1| Appendix D | 11102656 (4)

Figures

APPROXIMATELIMITS OF

CONSTRUCTION

TAPC

O ROAD

VERDE RIVER

SYCAMORE CANYON ROAD

LOWER TAPCORIVER ACCESS

POINT

EXISTINGSLAG PILE

0.2% ANNUAL CHANCEFLOOD HAZARD

1.0% ANNUAL CHANCEFLOOD HAZARD


PROPERTY LINE

0.2% ANNUAL CHANCE FLOOD HAZARD

1.0% ANNUAL CHANCE FLOOD HAZARD

CENTERLINE OF VERDE RIVER

LEGEND: N

DateReport No.Project No.

Filename: G:\111\11102656 - Sycamore Canyon\CADD\Drawings\Figures\111-02656-FIGURE D-1.dwgPlot Date: 20 June 2018 - 1:20 PM

FREEPORT MINERALS CORPORATIONSYCAMORE CANYON LINED SOIL REPOSITORY

FIGURE D-1PRE-CONSTRUCTION SITE PLAN

111536814JUNE 2018

Source:

FIGURE D-1

0 160'80'

PLANSCALE: 1" = 80'

LEGEND:

EXISTING MAJOR CONTOUR

EXISTING MINOR CONTOUR

PROPERTY LINE

3450

3449


POTENTIALEQUIPMENT STORAGE

AREA

TEMPORARYSTOCKPILE AREA

(IF NEEDED)

CONSTRUCT TRUCKDECONTAMINATION PAD

CONSTRUCT CHAINLINK SECURITY FENCE

INSTALL LOCKEDGATE

CONSTRUCT NEWGRAVEL HAUL ROAD

CONSTRUCT STORM WATERCONTAINMENT BASIN

(SEE NOTE 1)

TRANSITION INTOEXISTING DRAINAGE

CONSTRUCT EASTRUN-ON CONTROLCHANNEL

REPOSITORYBERM

PROVIDE GRAVEL ACCESSRAMP INTO REPOSITORY

CONSTRUCT NEW ACCESS ROADAND TIE INTO EXISTING PAVEMENT

CONSTRUCT SPILLWAYAND TRANSITION TOEXISTING DRAINAGE

PERFORATEDHDPE TOE DRAIN

PERFORATED HDPETOE DRAIN

3450

3445

34403435

3430

3425

3420

3510

350535

00

3495

3490

3485

3505

3445

3450

34553442

3450

3445

34403435

3430

3425

3415

3435

344034

45

3465

3470

3465

3460

3455

3450

3460

3456

3465

3455

3450

3446

3460

3462

3443

3444

3443

-0.5%

X

X

X

X

X

X

X

X X X X X X X X X X X X X X X X

XX

XX

XX

XX

XX

XX

X

X

X

X

X

X

X

XX

X

X

X

X

X

X

X

X

X

X

X

X

X

X

-3.0%

-3.0%

X PROPOSED FENCE

NNOTES:

1. STORM WATER CONTAINMENT BASIN TO BE CONSTRUCTEDPRIOR TO THE PLACEMENT OF MATERIAL WITHIN THE SOILREPOSITORY AND MAINTAINED FOR THE DURATION OF THEPROJECT.

2. SILT FENCE TO BE INSTALLED AROUND DISTURBED AREA.

LINED SOILREPOSITORY

LINEDSTORMWATERCONTAINMENT

BASIN




FIGURE D-2REPOSITORY SITE PLAN

111536814JUNE 2018

Source:

FIGURE D-2

AD-4

AD-4

PLANSCALE: 1" = 80'

0 160'80'

EQUIPMENTSTORAGE AREA

EAST RUN-ONCONTROL CHANNEL

CONSTRUCT DOWNCHUTE (TYP)

X

X

X

X

X

X

X

X X X X X X X X X X X X X X X X

XX

XX

XX

XX

XX

XX

X

X

X

X

X

X

X

XX

X

X

X

X

X

X

X

X

X

X

X

X

X

X

ACCESS ROAD

3460

3465

3470

3475

3480

3485

3490

3510

3510

3515

3520

3525

3530

3535

3540

3545

35503555 35

60 3565

35653570

3570

3445

3450

3455

3460

3465

3470

34753480

3485

3490

3490

3495

3495

3500

35003505

3505

3510 3510

3415 3420 3425

34303435

3440

3445

3450

3420

3425

3430

3435

3440

3445

3450

3495

3500

3505

3510

3435

3440

3451

3453

3468

3452

3454 3455

3445

3450

3446

3447

3448

3449

3443

3444

3470

3472

34733474

3472

LEGEND:

EXISTING MAJOR CONTOUR

EXISTING MINOR CONTOUR

3450

3449

X PROPOSED FENCE

PROPOSED MAJOR CONTOUR

PROPOSED MINOR CONTOUR

3480

3479

PLANSCALE: 1" = 80'

NNOTES:

1. SOIL REPOSITORY DESIGN CAPACITY: 150,000 CUBICYARDS. ACTUAL QUANTITY PLACED WITHIN THE SOILREPOSITORY MAY VARY DUE TO THE VOLUNTARYPARTICIPATION NATURE OF THE UNITED VERDE SOILPROGRAM.

CAPPED SOILREPOSITORY


BASIN




FIGURE NO. D-3REPOSITORY COVER - GRADING PLAN

111536814JUNE 2018

Source:

FIGURE D-3

AD-4

AD-4

0 160'80'

2C004

REPOSITORY PROFILENTS

REVEGETATION

RECOMPACTEDSUBGRADE

DEPT

H VA

RIES

24" (

MIN)

COMPACTED UVSPEXCAVATED SOIL

60 MIL TEXTUREDGEOMEMBRANE

GEOCOMPOSITE DRAINAGE LAYER

24" LAYER OF COVER SOIL

12" LAYER OF SCREENEDEXCAVATED SOIL

STATION

3435

3440

3445

3450

3455

3460

3465

3470

3475

3480

3485

3435

3440

3445

3450

3455

3460

3465

3470

3475

3480

3485

B-0+50 B0+00 B0+50 B1+00 B1+50 B2+00 B2+50 B3+00 B3+50 B4+00 B4+50 B5+00 B5+50 B6+00 B6+50 B7+00 B7+50 B8+00 B8+50 B9+00 B9+50 B10+00




FIGURE NO. D-4REPOSITORY DETAILS

111536814JUNE 2018

Source:

FIGURE D-4

SECTIONAD-3 N.T.S.SCALE :

SOIL REPOSITORY


BASIN

EXISTING GRADE

FINISHED GRADEREPOSITORY COVER

FINISHED GRADEREPOSITORY LINER SYSTEM

14

FINISHED GRADE LINEDSTORMWATER CONTAINMENT BASIN

1% TYP.

11

PERIMETER BERM

Re: Remedial Action Work Plan – Revision 1 United Verde ... RAWP Revision 1... · 7560 N La...

Documents

Transcript of Re: Remedial Action Work Plan – Revision 1 United Verde ... RAWP Revision 1... · 7560 N La...