INTRODUCTION TO THE UNITED VERDE MINE PROJECT€¦ · The United Verde Mine Project: Preserving an...

The United Verde Mine Project:Preserving an Arizona Treasure

INTRODUCTION TO THE UNITED VERDE MINE PROJECT

Perched high on a mountain overlooking the Verde Valley, the Town of Jerome and surrounding historicmining district, including the United Verde Mine, draw tourists from all parts of the United States andaround the world. The United Verde Mine operated from the late 1800s through the early 1950s, and iscurrently owned by Freeport-McMoRan Corporation, a wholly owned subsidiary of Freeport-McMoRanCopper & Gold. As at many historic mine sites, the United Verde Mine required upgrades to protectsurface water and groundwater resources from being impacted by mine seepage and stormwater thatcontact acid generating mine-rock stockpiles.

Freeport-McMoRan approached the United Verde Mine Project with the objectives of reclaiming mine-rock stockpiles and implementing a stormwater management and solution containment program.Freeport-McMoRan prioritized reducing the volume of stormwater flowing onto and seeping throughthe stockpiles as a key component of the design. Freeport-McMoRan constructed evapotranspirativesoil caps on several stockpiles, a 1.5 mile stormwater diversion channel to divert upstream stormwateraround and through the project site, and a clean water channel to allow unimpacted flows to passthrough the property unimpeded. Freeport-McMoRan also made working with and supporting thelocal community during the project a priority. In response to community needs and to support the longterm sustainability of the local economy, Freeport-McMoRan constructed a desperately needed pavedparking area to accommodate the tourist crowds on which the local economy depends. Because ofthe rugged terrain, the Town lacked a safe landing zone for emergency medical evacuations. Freeport-McMoRan constructed a paved helipad to provide a safe landing zone. The parking area and helipadwere incorporated into the design of a stockpile cap. In addition, the project provided other neededinfrastructure improvements, including sewer and water lines. The project features are currentlyfunctioning as designed: protecting surface water and groundwater, and enhancing the lives of thesurrounding community.

Statement Summarizing Why Award is Deserved

The Hard rock Mineral Director's Award:The United Verde Mine Project exemplifies Freeport-McMoRan's commitment to doing the rightthing, the right way, the first time and in a safe manner. Freeport-McMoRan applied an innovativeapproach to managing acid rock drainage, meeting engineering challenges and exceeding regulatoryrequirements. At Freeport-McMoRan it is not just about the company, it is about their people and theircommitment to honesty, community, safety and environmental health.

The Hard rock Mineral Environmental Award:The United Verde Mine Project is an outstanding example of applying a philosophy of environmentalstewardship and sustainable development to environmental compliance. Freeport-McMoRanprioritized pollution prevention as a key project component, and developed unique multiple useobjectives in coordination with the local community.

The Hardrock Mineral Community Outreach and Economic Security Award:Freeport-McMoRan demonstrates a clear commitment to local economic security and socialinfrastructure through the incorporation of facilities critical to the Town of Jerome's success into theUnited Verde Mine Project. The success of this project is measured not only in improvements to theenvironmental, but also in accolades from the neighbors.


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HISTORY OF THE UNITED VERDE MINE

Mining and the Town of JeromeThe first mining claims in the Jerome area were staked in1875, and the United Verde Mine began operations as anunderground mine that same year. Operations were intermittentduring the mine's first decade. The first smelters were built in1885 above the present-day open pit. With the introduction ofrailroads in the area in 1888, production increased, and a newsmelter was built in 1894. By 1900, the United Verde Mine wasthe largest mine in Arizona, and the sixth largest in the world,producing 20,000 tons per year of refined copper.

By 1910, the underground mining, combined with undergroundmine fires which had been burning since 1894, causedsubsidence of the ground surface, threatening the smelter andother facilities. In 1915, a new smelter in nearby Clarkdalebegan operating and open pit operations were initiated in1918. Production of refined copper peaked in 1918 at 35million pounds per year. In the mid-1920s, the copper marketrebounded somewhat from its post-World War I decline, andUnited Verde added a concentrator to the Clarkdale operations.Economic conditions during the Great Depression resulted ina cessation of mining from 1930 until 1935. By this time, oreproduction was entirely from the open pit mine, but subsequentdiscoveries of additional underground reserves revivedunderground operations in 1937.

By 1940, the open pit ore reserves were exhausted andmining from the pit stopped after reaching the 630 level.World War II revived the copper economy and made possiblethe underground mining of otherwise non-economic ores.Underground mining continued at a progressively slower rateinto the early 1950s, and ceased in 1953.

The business district of Jerome burned three times between1897 and 1899 and was rebuilt each time. Jerome had apopulation of 2,860 in 1900, and 2,400 in 1910, and includedimmigrants of diverse ethnic backgrounds. The demand forcopper exploded during World War I and population increasedto 7,000 by 1916, jumped to 10,000 a year later, and reacheda peak population of 15,000 residents by 1929, making itArizona's third largest city (Sargent 1988; Trimble 1986).Jerome never recovered from the stock market crash of 1929.After mining shut down in 1953, the population declined toabout 100 (Sargent 1988; Trimble 1986). The Jerome HistoricDistrict is a designated National Historic Landmark and theTown, with a current population of about 500, has become aheritage tourism destination and artist colony.


The project site is describedmainly in terms of two majordrainages, the Section HouseCanyon and the Bitter Creek.The site is further described interms of areas, the 300-Level,500-Level and the HopewellTunnel area. The 300-Levelstockpile and seepagecontainment are located inthe Bitter Creek drainage andthe 500-Level and Hopewellfacilities are located in SectionHouse Canyon. Material fromboth underground and open pitmining was deposited in on-sitedevelopment rock stockpiles onthe 300-Level, and the HopewellNorth and South Stockpiles.Much of the development rockis sulfide-bearing and acid-generating.

Capping a Stockpile in the Hopewell area

After closure of the underground operations, groundwater rose into the workings and discharged out ofthe Hopewell Tunnel, the main haulage tunnel for the underground operations. At that time, a series ofearthen impoundments was constructed to contain the drainage on site. Earthen impoundments werealso constructed to contain impacted runoff and seepage from the sulfide bearing stockpiles.

New Clean Water Channel in the Hopewell Area


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PROJECT DESCRIPTION

Project ObjectivesThe main objectives of theproject were to reclaim mine-rockstockpiles and to implement astormwater management andsolution containment program. Akey component of the stormwatermanagement and solutioncontainment design was reducingthe volume of impacted flowsrequiring containment on sitethrough diverting stormwater andcapping stockpiles. To achievethis:•A large diversion channel

(more than 1.5 miles long)and a clean water corridorwere constructed

•Acid generating stockpileswere cappedSeveral seepage andevaporation impoundmentswere constructed and/orupgradedWater was diverted back into the mine working using gravity flow for eventual treatment at theHopewell tunnel

Construction of the Section House CanyonStormwater Diversion

Sewer seepage and evaporation impoundments were constructed and/or upgraded. Additional projectobjectives included:

•Completing the project safelywith zero incidents

•Complying with all applicableregulations and permits inplanning a "zero dust" goal

•Minimizing disturbances to theTown of Jerome residents andbusinesses

Construction of New Evaporation Impoundments

Design and PermittingThe project required years ofdesign and permitting prior tocommencement of construction.Since 1994, the designs havebeen revised and refined tooptimize effectiveness andconstructability. Environmentalpermits required for theproject included an ArizonaAquifer Protection Permit(APP) and a Clean Water Act(CWA) Section 404 permit.A consent decree with the


C Environmental Protection Agency (EPA) required Freeport-McMoRan to construct a soil cap on the300-Level stockpile and to upgrade the pump system at the toe of the 300-Level stockpile. The consentdecree also imposed timelines for implementing the upgrades needed to comply with the APP Noneof the applicable permits required diversion of clean water, reduction of the volume of impacted watergenerated, or capping stockpiles other than at the 300-Level.

The Arizona APP program requires operators of facilities that may discharge to groundwater toobtain permits, which may require facility upgrades to reduce discharges to Arizona aquifers.Freeport-McMoRan applied for an APP for the United Verde Mine. Freeport-McMoRan completed acharacterization of the site hydrogeology and submitted an initial upgrade design in October 1994proposal to the Arizona Department of Environmental Quality (ADEQ). In subsequent years the designwas significantly revised and refined, and an addendum to the application was submitted to ADEQ inAugust, 2000. An APP was issued by ADEQ on February 22, 2007, requiring the construction of theimpoundment upgrades presented in the August 2000 application addendum.

In 2004, a CWA Section 404 Nationwide Permit (NWP) was sought with the U.S. Army Corps ofEngineers (USAGE) because the project construction activities involved placement of dredged orfill material in nearby waters of the U.S. The Section 404 permit program required identification ofthe waters of the U.S. (Jurisdictional Delineation) potentially impacted by the project, an analysis ofthe extent of impact and compliance with the Endangered Species Act (ESA) and National HistoricPreservation Act (NHPA). USAGE issued a Letter of Authorization for the project on Sept. 14, 2006,with several important conditions.

Although the project had been determined to have no impact to endangered species within theESA program, impacts to cultural resources regulated by the NHPA were anticipated. The Letter ofAuthorization permitted project activities outside of a buffer area around identified cultural resourcessites pending agency approval of plans to study these sites. Gonsultation between USAGE, StateHistoric Preservation Office (SHPO) and the U.S. Department of Interior's Advisory Gouncil onHistoric Properties (AGHP) was required under Section 106 of the NHPA; and the National Park

Service (NPS) was invited to participate. TheAGHP's involvement was required (and theNPS invited) because the Town of Jerome is aNational Historic Landmark, and the landmarkboundaries intruded into the project area onFreeport-McMoRan land. Accordingly, the threeagencies were required to coordinate theiractivities in accordance with a project-specificMemorandum of Agreement (MOA) and alsoto approve the Historic Properties TreatmentPlan (HPTP) describing the cultural resourcesdata recovery effort. The HPTP and MOA weresubmitted to the agencies for review in January2005. The HPTP and MOA were also submittedto eight potentially interested Native Americantribes for review. Goordination of agency reviewand approval required more than 2 years forUSAGE to accomplish. Full execution of theMOA was completed on March 8, 2007, andUSAGE authorized implementation of the HPTPon March 15, 2007. Data recovery fieldworkand cultural resource clearance was initiatedimmediately and was completed by September2007.

A Leader in Good Environmental Practices,Minimizing Environmental Degradation,

Promoting Sustainable Development andPreventing Pollution

Good environmental practices included:•Reducing the generation of impacted water•Implementing a "zero dust" goal during

construction•Installing silt fences, hay bales and waddles

around the project perimeter to control siltduring rain events

•Installing stormwater control benches andhay waddles on capped stockpile faces toprevent erosion

•Minimizing noise by adhering to strictworking hours

•Reducing light pollution by installingdownward-directed opaque reflector lampsat the 300-Level parking lot

•Reducing electricity consumption•Replacing leaky water and sewer lines


Engaging Local Communities and PublicParticipation - Consultation for Entire

Project Life

Frequent meetings with Town of Jerome officialsencouraged an open dialogue regardingresidents' ideas and concerns. As a result ofthese meetings, Freeport-McMoRan:

Constructed a paved parking lot for touristuseConstructed a paved helipad for emergencyhelicopter access

• Provided buildings with paved access foruse as Town maintenance shopsEnhanced the historic character of theparking area through the selection of period-appropriate light fixtures and fencingMaintained the historic feel of the 300-Levelstockpile by capping at the angle of repose

Construction0o( rConstruction commenced in April 2008 and wascompleted in less than 16 monfhs, significantlyahead of the originally projected 24 months.During the construction, Freeport-McMoRanworked closely with consultants and contractorsto resolve unforeseen issues and to complete theproject ahead of schedule.

Stormwater diversion was accomplished throughthe construction, mostly in bedrock, of a 1.5 milediversion channel in Section House Canyonto recovered non-impacted run-on and conveythese flows around the disturbance area. Aspart of the diversion, a box culvert was installedunder Perkinsville Road, a Yavapai County road.The diversion channel receives non-impactedstorm run-on and diverts the flow around thedisturbed areas. A clean water channel wasconstructed below the Hopewell Tunnel toconvey clean water from Section House Canyonthrough the project area and off-site into anatural drainage. In addition to

The scope of the construction work included:•Capping the 300-Level stockpile,

incorporating a paved parking area andhelipad, replacing a main water supply lineand other water and sewer lines during theconstructionUpgrading an emergency pump system at the300-Level stockpile toe

•Installing a gravity drain-hole at the 500-Level•Installing a 1.5 mile stormwater diversion

channel in the upper reaches of SectionHouse Canyon and clean water channelbelow the Hopewell area

•Capping of waste-rock stockpiles containinghigh concentrations of sulfide minerals in the Hopewell area

•Installing 5.9 acres of lined stockpile seepage impoundmentsInstalling a treatment channel at the Hopewell Tunnel

The 300-Level stockpile was covered using an evaportranspirative cap and an asphalt parking lot andemergency helipad for the Town of Jerome. The source of seepage observed in the past form the toeof the 300-Level was unknown, and a directionally-drilled drain-hole was originally proposed at thestockpile toe. During construction, Freeport-McMoRan was able to successfully locate several sourcesof seepage, including an old septic system and leaking water and sewer lines. The seepage sourceswere eliminated by replacing the lines that were still in use and shutting off those that were not. As aresult, no seepage has been observed at the toe of the newly capped 300-Level stockpile except afterextreme precipitation events. As an emergency safeguard, the existing system to pump seepage to the

open pit was upgraded. Any seepage pumpedfrom the toe of 300-Level will eventually exit themine workings at the Hopewell Tunnel where itwill enter a treatment channel and be collectedfor evaporation.

Promoting Health and Safety (H&S)On and Off the Job Site

Freeport-McMoRan is committed to theelimination of all workplace injuries andillnesses. We believe that our most importantasset is our people and that reaching zeroincidents and maintaining that standard is theonly morally acceptable level of performancein H&S management. Our vision of SafeProduction encompasses not only safety inthe workplace but also extends to off-the-jobactivities at home and within the communitiesin which we do business. Freeport-McMoRancompleted the construction in 16 safemonths with no reportable accidents orincidents.


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•Reduced the total volume ofimpacted watersCreated a clean waterchannel allowingunimpacted surface water toflow off siteCapped stockpilescontaining acid-generatingrock

•Limited the site's carbonfootprint through emphasison gravity driven flow

•Enhanced economicsecurity of the local

¦ communityCapping Stockpiles in the Hopewell Area

diverting water away from the project area, the diversion channel also diverted flow away from asection of Perkinsville Road, which will result in decreasing the County's care and maintenance costs.

The Hopewell stockpiles were graded and covered with evapotranspirative caps to reduce infiltrationof precipitation and the resulting generation of acid rock drainage. The caps also prevent stormwaterfrom contacting the acid-generating material in the stockpile. As a result, stormwater run-off from thestockpiles is unimpacted and can be allowed to flow off site. Not all of the stockpiles at the site werecovered, mainly because capping some did not provide an environmental or improved water qualitybenefit. Capping those stockpiles would have resulted only in a limited aesthetic benefit at a significantcost, and the aesthetic benefit is questionably as the Town was interested in maintaining the historicmining appearance of the area.

Several seepage and linedevaporation impoundments wereconstructed in the 500-Leveland the Hopewell Tunnel areasto contain and evaporateimpacted run-off that should notbe discharged to Section HouseSprings Canyon or could not bediverted because of topographicchallenges.

A 300-foot gravity drain-holeat the 500-Level was installedto direct seepage away fromSection House Canyon andback into the mine workingsto overcome topographicalchallenges associated with

Construction of a Box Culvert Under Perkinsville Road conveyance and the lack ofPart of a 1.5 Mile Stormwater Diversionelectrical power. The redirected


( 300-Level Capping Before

flow from the 500-Level will eventually exit the mine workings at the Hopewell Tunnel, where it willenter a treatment channel and be collected for evaporation.

Project Challenges and SolutionsProject challenges included:

Extensive project area with numerous historic mine features, steep terrain and lack of electricalpowerProximity of the project to the Town's residential and commercial tourist areas

• Oversight by multiple entities, including the EPA, USAGE, ADEQ, Yavapai County, the ArizonaDepartment of Transportation (ADOT) and the Town of Jerome

Both the terrain and lack of electrical power required innovative ideas to overcome design challenges -with steep, rugged terrain. Solutions requiring the least amount of impoundment assistance andmaintenance were the most desired. The project area covers more than 1.5 square miles and includesmultiple surface water drainages. Section House Canyon alone drains more than 2.3 square miles ofsurface area. Lack of electrical power throughout most of the project area restricted the use of pumpsto convey water. These design challenges were overcome through creative solutions such as usinga 300-foot gravity drain-hole at the 500-Level to direct seepage away from Section House Canyonand back into the mine workings. This design also eliminated the need for construction of a pipelinethrough rugged terrain. Another creative design component was capping stockpiles and diverting clean

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Hopewell Area Stockpile Capping and Impoundment Upgrades After

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water around and through the project area to achieve a 70 percent reduction in the volume of surfacewater contacting acid-generating materials and requiring containment.

Challenges related to the proximity of the project to the Town were overcome through strict adherenceto project protocols designed to limit impacts to Town residents. Disruptions to the Town of Jeromeresidents, business and tourists were minimized by transporting equipment on historic mine roads andavoiding Arizona State Highway 89A which winds through the heart of Jerome. When the use of StateHighway 89A was unavoidable, deliveries were escorted and only scheduled during times of low touristtraffic, usually late evenings. Construction activities were conducted in conformance with all applicableenvironmental permits obtained for the construction, and with a Freeport-McMoRan "zero dust" goal, inconsideration of the Town's desire to maintain a historic mining ambiance, the 300-Level stockpile wascapped at the angle of repose, and period-appropriate parking lot features were selected.

The challenge of obtaining the necessary permissions and approvals from numerous local, state andfederal agencies was met by communicating frequently and transparently to all agencies involved.

Community ActivitiesFreeport-McMoRan met frequently with Town of Jerome officials to provide updates on the projectdesign, construction plans and the construction activities. The frequent and open communicationprovided the Town officials with a clear understanding of the project and a forum for voicing concerns


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Installation of Impoundment Liner

and making requests. On May 21,2007, Freeport-McMoRan held apublic open house to inform thetownspeople of the details of theupcoming construction project andanswer questions.

During the design stage of theproject, the Town of Jeromeofficials approached Freeport-McMoRan with a request tomodify the soil cap design forthe 300-Level stockpile. TheTown of Jerome was desperatefor additional parking toaccommodate the tourist crowdson which their economy depends,and petitioned Freeport-McMoRanto change the design to include apaved parking lot on the top of the


C stockpile. Freeport-McMoRan brought the Town's request tothe EPA and received permission to change the cap design toaccommodate the Town's needs.

Town of Jerome officials also identified the need for anemergency helipad, and Freeport-McMoRan agreed toconstruct one adjacent to the paved parking lot. Prior toconstruction of the helipad, seriously ill or injured patients inJerome had to be transported by approximately five miles byambulance down a steep, narrow mountain road to reach asafe, flat location where a helicopter could land. Constructionof the helipad provides a safe landing zone within the Townlimits, allowing patients to be flown directly from Jerome to aLevel 1 trauma center in Flagstaff or Phoenix.

Freeport-McMoRan also agreed to complete several badlyneeded infrastructure improvement projects for the Town ofJerome. Because of the difficulty and expense of mobilizingheavy construction equipment to Jerome, this service wasparticularly beneficial to the Town. Freeport-McMoRanreplaced the main water supply line from the town holdingtanks, replaced water and sewer lines on the 300-Level andprepared an area for future water holding tanks. Freeport-McMoRan also repaved and provided new curbs and gutterson a stretch of Perkinsville Road, the county road that crossesthe 300-Level stockpile. Freeport-McMoRan paved the areaaround several buildings so that the Town of Jerome can usethe facilities as a maintenance shop.

Throughout the course of the project, Freeport-McMoRansupported numerous sustainability projects in the Town ofJerome. Charitable contributions from Freeport-McMoRansupported renovations of a historic school house to serve asthe new library, purchasing computers for the library. Freeport-McMoRan also contributed to the Jerome Historical Society fordeveloping story boards explaining historic features at variouslocations around town.

Freeport-McMoRan supports the preservation of Jerome'sunique and colorful mining history. Freeport-McMoRan restoredthe United Verde Administrative Office building and opened itsdoors for public viewing as part of the Jerome 2008 HistoricHomes Tour. The Administrative Office was built in 1919and originally served as an apartment and office for SenatorWilliam Clarke (Wright, 2008). The building serves as Freeport-McMoRan's local offices. Freeport-McMoRan also supportsthe Jerome State Park, an Arizona state park located withinthe Town limits and dedicated to preserving the history of theJerome area. Freeport-McMoRan donated a scale model ofthe underground workings to the Park, and also chose the parkto be the curator of all materials and items collected duringthe archeological study of the site. Approximately 75 percentof the items in the museum have been donated by Freeport-McMoRan and its legacy companies (Source: Mike Rollins,Manager, Jerome State Park).

INTRODUCTION TO THE UNITED VERDE MINE PROJECT€¦ · The United Verde Mine Project: Preserving an...

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