ENVIRONMENTAL AND WATER QUALITY ISSUES · 2009. 5. 8. · highly controversial when they conflict with other land uses or preservation. Near Sandpoint, Idaho, a mining company wants

ENVIRONMENTAL ANDWATER QUALITY ISSUES

D E C I S I O N - M A K E R SF I E L D C O N F E R E N C E 2 0 0 5

T a o s R e g i o n

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DECISION-MAKERS FIELD GUIDE 2005

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Rio Grande in fall color, near Embudo.

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MINING IN NEW MEXICO

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ries) of mining and mining accidents and pollution.Their understanding of the role that mining hasplayed economically, either positive or negative, typi-cally comes directly from experience.

The generally negative perception of mining is bal-anced by an almost unanimous desire for mining,when it occurs, to be done the right way. The public isnot anti-mining and is well aware of the material andeconomic needs that are met by mining the earth'scrust. People understand that they benefit from theproducts created by mined materials, and they want tocontinue to enjoy those benefits but as one focusgroup respondent stated: “There must be a way to doit right.” This sentiment was shared by virtually everyfocus group member in every focus group that wehave conducted. The public wants tougher miningsafeguards, and they want greater corporate responsi-bility-in fact they expect it.

TOUGHER STANDARDS AND INDEPENDENTVERIFICATION ENHANCE PUBLIC CREDIBILITY

Many in the mining business acknowledge that theindustry has a public-perception problem; some evenacknowledge that they have a reality problem. In 2000a number of major mining companies sponsored amulti-year study known as the Mining Minerals andSustainable Development (MMSD) project andlaunched a major effort to reposition the industry,including the creation of a new global trade associa-tion with a mandate to address issues related to sus-tainable development—the International Council onMining and Metals (ICMM). There is, however, a splitin the industry as to whether improving public per-ception is a matter of better performance or just betterpublic relations. Those who look at the issues serious-ly recognize that better performance is essential to abetter reputation. They are therefore focusing theirtime, energy, and resources on practices and perform-ance first, rather than public relations. They also rec-ognize that an essential component of a better reputa-tion is an acknowledgment of improvements fromthose outside the mining industry—e.g., non-govern-mental organizations (NGOs), regulators, academics,investors, insurers, and those that market and sell

Mining operations of one type or another havebeen altering our landscape since the dawn of

civilization. Today there is growing evidence that pub-lic opinion and the political landscape within whichmining operates is altering as well. This is due prima-rily to conflicts over land use and public values.

Pollution…air, water and land pollution-it runs thegamut…the destruction of beautiful mountains andvalleys…the Berkeley Pit is one of the biggest toxicwaste sites in the country…cyanide…jobs…naturalresources…helped build the country…destroys thecountryside…its better than it used to be…theyhaven't figured out a way yet to deal with the harmfulbyproducts and keep the land healthy…what do wehave to show for it…what's it going to do for us oncethe mine is gone and they've ruined the environmentand the jobs are gone…employs a lot of people and Isupport it but I wouldn't want to live near amine…there must be a way to do it right.

These excerpts from focus groups commissioned byEARTHWORKS in 2003 in Billings, Montana, LasVegas, Nevada, and Seattle, Washington, offer a sam-pling of public attitudes about mining today. And theymatch the views expressed in focus groups andpolling that we sponsored in 2000, with one signifi-cant difference—although mining remains a remoteactivity for most, there is a growing awareness of itsimpacts particularly in states with significant currentor historical mining activity. The participants in the2003 focus groups were more able to cite specificmining accidents and even specific types of pollutionsuch as cyanide spills or acid mine drainage.

There is a difference between public awareness inmining regions as opposed to those regions wherethere is little large-scale mining. For example, peoplefrom non-mining urban areas like New York,Baltimore, and Chicago have a vague but somewhatnegative impression of mining. Their views are shapedto a great extent by historical images of coal mining.People in the West, even the urban West, have oftenseen mines, have family members or friends whowork in the mining industry, and can draw uponimages (from both actual experiences and media sto-

Public Perspectives on Mining—“There Must Be a Way toDo It Right”

Stephen D'Esposito, EARTHWORKS

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products that use metals such as jewelry retailers andhigh-tech companies. Many realize that the public islikely to see the cues that come from these groups out-side the mining industry as more credible than thosethat come directly from the mining industry or frommining industry-sponsored groups or trade associa-tions. The public tends to discount self-promotion, asit should. It is always better to have someone else patyou on the back or offer kudos.

Interestingly, the two ingredients that are essential toimproving the practice, performance and reputation ofthe mining sector—stronger government regulationsand mechanisms for independent, third-party verifica-tion of responsible practices—are fiercely controversialwithin the mining sector.

In regard to stronger mining laws and regulations, anumber of mining companies have asserted to me thatthey are better corporate citizens but they are not get-ting credit for it. In the U.S. a number of the majormining companies appear to have become smarterabout where they propose mines. Yet, some companiesstill propose mines near national parks, underWilderness areas, or in important watersheds. As aresult, the reputation of the entire industry is tar-nished. Laws or regulations that block irresponsiblecompanies from proposing mines in these areas actual-ly enhance the reputation of the industry and allowcompanies to focus investment resources for mines inmore suitable areas.


In regard to independent certification of perform-ance, instead of movement toward independent stan-dards and verification, there appears to be a preferencein the mining industry for self-imposed, first-partystandards regarding environmental and social perform-ance. This strategy lacks transparency, credibility, inde-pendence, and legitimacy. It would be like Pepsi con-ducting a taste test to compare itself to Coca-Cola,without blindfolds and using its own employees.Fortunately, there is recent evidence that some leadersin the industry may be willing to participate in thedevelopment of an independent, third-party verifica-tion scheme, with standards developed through atransparent process and with participants from multi-ple sectors. This is a potentially significant develop-ment.

It is true that the reputation of the entire industrysuffers because of the “bad apples,” a point made onnumerous occasions by leaders in the mining industry.Stronger mining regulations and independent verifica-tion schemes could begin to differentiate publicly theleaders from the laggards—and should provide reputa-tional, financial, and regulatory rewards to leaders inthe industry. Such an approach is a risky strategy onlyfor the laggards. It is a shrewd strategy for those whoconsider themselves to be industry leaders and arewilling to prove it. Those who pursue this strategymay be less popular at trade association sponsoredcocktail parties but are likely to find themselves morehighly regarded by investors, insurers, and the public.

VALUES VS. TECHNICAL ARGUMENTS ABOUT HOTBUTTON ISSUES

There are today a number of hot-button issues thattend to foster public controversy and push the reputa-tion of mining into the negative column. I willdescribe two such issues: 1) mine location and land-use conflicts and 2) responsibility for closure andcleanup and the definition of responsible reclamation.In each of these examples the public is listening toarguments that are both technical and value-laden, butthe industry is typically making only technical argu-ments. Mining company officials too often act as if theless-quantifiable values held by the public are irrele-vant.

Mine Location and Land-Use Conflicts

Modern industrial-scale mining can alter landscapes,water systems, economies, and communities, often inways that are permanent or long-lasting. Therefore, it

Placer Dome's Golden Sunlight gold mine near Whitehall,Montana.


should come as no surprise that mining proposals arehighly controversial when they conflict with otherland uses or preservation.

Near Sandpoint, Idaho, a mining company wants tomine under the Cabinet Mountain Wilderness Areaand they want to place the tailings in an unlined pilenear the Clark Fork River, threatening clean water, thescenic beauty of the area, endangered grizzly bears,and trout populations. Most people in Sandpoint, anda vast majority of business leaders, oppose the mine;they do not believe this is an appropriate place for amine or for the mine waste that would result.

However, because of the nature of the laws and theregulatory process, the policy-making process fails toadequately account for the key public concern—thesuitability of the location and the fact that the publicvalues keeping the land, and its wildlife and other nat-ural resources, in a protected state. Instead, the debatetakes place through competing scientific and technicalstudies regarding the potential impacts of the mine.These studies are essential, but they fail to address theunderlying question of land suitability. The mecha-nisms that do offer some protection, such as landwithdrawals, are not always adequate or effective.Some public officials have had to resort to expensive,complex, and messy buyouts and land exchanges toprevent mine development. What's lacking is aprocess that allows for the effective and efficientweighing of land uses that should be at the heart ofgood land use planning and decision making.

Until we begin to develop standards and norms formaking appropriate land use decisions, standards andnorms that are also accepted by nearby communities,

civil society groups, mining companies, and otherstakeholders, these conflicts will continue, and theindustry as a whole will be swimming against the tideof public opinion and public values.

Defining and Paying for Closure and Cleanup

A prevalent theme in focus groups, particularly inwestern cities, is that the mining industry has a repu-tation for walking away from mine cleanup liabili-ties—to oversimplify, as one focus group participantput it: “They get the gold, we get the pollution messand the bill for cleaning up the mine.”

There is a historical component to the problem.Some of the worst sites on the Superfund NationalPriorities List are mines. Then there are abandonedmines that are not part of the Superfund program.Several studies, using different definitions of an aban-doned mine, have arrived at different estimates for thenumber of such sites. For example, the WesternGovernors Association has estimated that there are250,000 abandoned mines in just the western states,but limited information from some states means thenumber could be higher. Using a different definition,Mineral Policy Center (now part of EARTHWORKS)has estimated that there may be as many as 500,000abandoned mines across the entire country. The pointis not the debate over the exact number, it's that theproblem is significant, particularly as more and morepeople begin to live or travel near these sites. There isalso a contemporary aspect to the problem. InMontana just a few years ago Pegasus Gold walkedaway from Zortman-Landusky and other mines leavingtaxpayers with a bill of at least $30 million. In March2003 Jim Kuipers authored a report that showed apotential $12 billion gap—the difference betweenexisting financial guarantees and what was likely to benecessary for adequate mine closure—at operatingmines in western states.

In the state of New Mexico it took years of citizen-generated pressure and dogged work by regulators torequire the mining companies running some of thestate's biggest copper mines to update and increasetheir reclamation bonds so that an adequate financialguarantee would be in place. Mining companies usedtechnical, procedural, and economic arguments todelay complying with New Mexico law requiring themto post an adequate mine reclamation bond. In a nar-row sense, these companies may have benefited in thatthey delayed posting the bond or perhaps decreasedthe bond amount through torturous negotiations anddelays. But in a larger sense the reputation of the min-

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Open-pit mine.


There is a compelling need for more independent sci-entific research and evaluation in the mining sector.

Too many of today's mines were approved basedupon environmental impact statements that under-pre-dicted impacts on water resources. Sound public poli-cy and sound natural resource planning require soundanalysis of the expected impacts—i.e., accurate predic-tions. Without accurate predictions, the public andregulators are being asked to make decisions in aninformation vacuum. We now have a data set for mod-ern industrial-scale mines in the western states thatspans decades. We should study the data set and learnfrom it. And that's what we are doing. EARTHWORKShas commissioned an independent analysis of environ-mental impact statements from major mines in thewestern U.S., and the predictive models that underpinthese assessments. We expect to have results in early2005.

Accurate predictions will enhance the public imageand credibility of the mining industry. It will alsoincrease the confidence of investors, insurers, and reg-ulators. After all, it's not just the environment that suf-fers if impacts are worse than predicted. The result canbe dramatically increased cleanup and closure costs,greater financial liability, costs associated with legalaction, government intervention, and a negativeimpact on corporate reputations. Environmental pro-fessionals in mining companies, in the consulting sec-tor, and in academia have a particularly important,and potentially catalytic, role to play in solving theproblems related to under-predicting impacts. If theydo not address these problems (if they rely uponincomplete or inaccurate predictions), they run therisk of being tarred with the same brush as some ofthe worst companies in the mining industry.

THE PUBLIC WANTS SOLUTIONS

Ultimately, the public is looking for solutions. Whatthey care about is not mining per se, but the products,resources, and way of life that mining makes possi-ble—e.g., a wedding ring, computers and cell phones,and fuel (whether for their own transportation or toget things to them like food, clothes, books, etc.).They want things that are essential as well as thingsthat are not so essential. They also want to protectpeople, communities, and the environment. Theydesire to have these products without doing harm, andthey desperately want to believe this is possible. Theywant to believe that corporations can act responsibly.But they know that without accountability some pretty


ing industry suffers. A good part of the public and thegroups representing nearby communities in thesestruggles now believe that all big mining companieswill fight paying to clean up the mess that they havemade. At its core this is an issue of public trust—asone participant put it: “It's about cleaning up the messyou made; we all learned this value as children.”

SCIENCE AS AN ALLY OF PUBLIC VALUES

Drawing a distinction between issues that lend them-selves to technical analysis and those that do not isnot an effort to paint science as an enemy of good,sound decision making on natural resource issues.Science is essential to good decision making. Theargument, however, is for the need to rely on both sci-ence and values in weighing public policy issues.

Acid mine drainage in Fisher Creek, Montana, from abandonedmine workings.


nasty things can happen. They are willing to makechoices as consumers, particularly in urban areas, topurchase responsibly sourced products. For example,they want to know how to recycle cell phones, com-puters, and other similar items, and they want theoption of knowing that their wedding ring comesfrom a responsible source, not one that violateshuman rights or environmental standards.

There are some positive signs. In Montana theStillwater Mining Company established a good neigh-bor agreement with nearby communities, agreeing toenhanced water protection provisions and an exten-sive water testing program. BHP-Billiton, Falcon-bridge, and Western Mining Corporation have allagreed not to engage in the practice of riverine tailingsdisposal at future mines. Recently the NewmontMining Company decided not to pursue its plan toexpand its mining operations to Cerro Quillish inPeru, a sacred mountain and key water source in theregion, stating that it had underestimated communityopposition. In October, Reuters News Service ran astory describing how BHP-Billiton had worked to gainparticipation and support from community groupsand NGOs like Oxfam for its Tintaya Copper mine inPeru. This past April, the world-renowned jewelerTiffany & Company called for reforms to outdatedmining laws and responsible sourcing of metals suchas gold and silver as well as diamonds. And Jewelersof America, the national trade association, publiclyexpressed support for responsible mining practices.

As a practical way forward, there are four reformsnecessary in the mining industry:

• A policy that allows for the designation of valu-able lands where mining may not be appropriate and the establishment of a mechanism to effi-ciently and quickly weigh land-use options. This must be determined early, before significant resources have been spent on development.

• An effective regulatory definition of necessaryreclamation of lands and other natural resources with a financial guarantee to cover these costs as a pre-condition of mining. And a fee on current mining should be established to begin to tackle the legacy of polluting abandoned mines.

• A company-specific and then industry-widecommitment to independent third-party certifica-tion of responsible mining practices.

• The promotion of recycling, re-use, and smart design to lessen our demand for virgin minerals,

in order to fully utilize, conserve, and re-use our valuable natural resources. We should mine met-als from cell phones, high-tech equipment, and other products.

As a society we will continue to draw resourcesfrom the earth for our survival, well being, and enjoy-ment. We will continue to dig, probe, quarry, shovel,and drill the earth for its resources, to find new mate-rials and new uses for existing materials. But there isgrowing evidence that we are beginning to alter ourviews as to how this should be done and under whatconditions. And there are signs that a new ethic ofmaterials responsibility is beginning to take hold forcommunities, the business sector, and governments.Materials responsibility begins where we begin tomine the earth's surface resources. And it begins byasking and answering two questions: What is the mostsustainable, most responsible, and most efficient wayfor society to meet its metals or materials needs, andwhen we need to mine, what are the standards thatshould and must be met?

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The environmental legacy of mining in New Mexicocan best be understood by examining human

health, water quality, and land use concerns, and regu-latory responses that have occurred over time. NewMexico shares approximately the same measure ofenvironmental legacy in terms of historic abandonedmine sites as that of other western states that havesimilarly undergone extensive exploration and devel-opment for minerals over the past 150 years. TodayNew Mexico has virtually no small to medium-sizedhard rock mining industry players, although eight ofthe 162 major hard rock mines that have operated inthe U.S. since 1972 are located in New Mexico.Although these mines only represent less than 5 per-cent of all hard rock mines in the U.S., it is significantthat the attention shown to them as a result of NewMexico's unique environmental regulatory process,both within the state and in the U.S., has made themamong the most important mines in the nation, froman environmental legacy standpoint.

HISTORIC MINE IMPACTS

New Mexico is home to possibly the oldest mine inNorth America in the Cerrillos Hills, where turquoisewas first worked by native people at least 1,000 yearsB.C. It is conceivable that New Mexico is also home tosome of the earliest mining-related environmentalimpacts. The impact of mining in the Cerrillos area isnoticeable, and historic mining activities in the regionhave presented safety issues that attract the attentionof the public and regulators today.

In 1820 Josiah Gregg, writing about placer opera-tions south of present-day Santa Fe, noted that in“some places the hills and valleys are literally cut uplike a honey-comb.” The workings observed by Greggwere created by Spanish miners and differed little fromother gold diggings in New Mexico during that time.

In New Mexico, as in most other western states, theprimary concern was with jobs and prosperity, and theenvironmental concerns of today scarcely entered thepicture. Prospecting and developing mines were allpart of the fulfillment of “manifest destiny” that was soprevalent during the settling of the western U.S. Untilthe early twentieth century and the coming of larger

mines and more obvious impacts, there was littlesense of serious environmental problems related tomining. However, in the latter 1800s and early 1900s,aided by the development of modern technologiesincluding nitroglycerin-based explosives and process-ing techniques, New Mexico's mining industry turnedfrom near-surface placer mining to underground hardrock mining-for silver, gold, lead, zinc, copper, andother minerals. In many cases the prosperous miningtowns of that era are today's abandoned miningtowns, with the worst of them destined to becomeSuperfund sites.

The Cleveland mill in Grant County, an abandonedlead, zinc, and copper mine and mill is one suchexample. Although the mine site itself only occupiesabout 4 acres, tailings have contaminated an addition-al 10 acres of the bed of Little Walnut Creek, andrunoff from the facility had acidified Little WalnutCreek and contaminated it with metals, which mayhave affected residential wells. Superfund cleanupactivities conducted in the 1990s for the Clevelandmill site included removal of the tailings to a reposito-ry, in addition to capping and revegetation.

Other legacies were less costly but still significant.In the Socorro area many mine shafts and adits wereleft open presenting a hazard to public safety. At thesame time a significant population of Townsend'slong-eared bats was discovered hibernating in theabandoned mine workings. New Mexico's AbandonedMine Land Bureau secured the mine openings in away that left them open for bat use.

More recently, New Mexico's response to environ-mental concerns has been characterized by a slownessto adopt regulations, followed by progress, but accom-panied by a failure to address the issue at the state'slargest mines. However, in the past five years thatobstacle has been removed, although with significantcompromise. The following discussions clarify some ofthe history that has led us to this point as well aswhere we might go in the future.

Uranium and Human Health Impacts

New Mexico was the scene of some of the earliestvanadium (and later uranium) mining in 1918 near

The Environmental Legacy of Mining inNew Mexico

James R. Kuipers, Kuipers and Associates



Shiprock. Despite extensive documentation fromEuropean uranium-radium mining districts and fromradium watch-dial painters about the health effectsamong miners and workers who were exposed to ura-nium decay products, work place protections were notadequate to protect miners and millers. By the early1960s evidence began to mount of lung cancer amongNavajo, Anglo, and Hispanic miners. Following exten-sive litigation against mine operators and the U.S.government demanding compensation for miners whoended up with lung cancer and other diseases causedby exposure to radioactive materials, the U.S. govern-ment agreed to establish a compensation program,acknowledging that workers had not been adequatelyinformed about or protected from known risks at ura-nium mines operated before 1971.

Since that time New Mexico has served as an exam-ple for major changes in mining industry practices interms of occupational safety and health, and for aunique national compensation program. In addition,New Mexico has developed and demonstrated urani-um mill tailings remediation techniques. Althoughmany concerns surrounding this very tragic situationhave yet to be satisfactorily resolved, the state haslearned a great deal from this issue.

HARD ROCK MINES AND WATER QUALITYIMPACTS

Hard rock mining environmental issues in NewMexico are most often identified with the state'slargest hard rock mines-specifically the Questa minein north-central New Mexico and the Tyrone andChino mines in southwestern New Mexico. Althoughvery different in terms of metal mined and geography,they have all received their share of attention from thepublic interest community and individuals who feelthey, or their environment, have been affected by themining operations.

Questa Mine

The Questa mine, now owned by Molycorp, beganproduction in 1918 of molybdenum disulfide orefrom underground mines. Open pit developmentbegan in 1964 and continued until 1982 by whichtime some 350 million tons of overburden had beenremoved and 81 million tons of ore had been mined.The overburden and waste rock was deposited ontosteep mountain slopes and into tributary valleysimmediately above and along the Red River. In 1983the mine went back underground using block cavingmethods.

The resulting impact on the environment has led toone of the most complex and therefore difficult mineremediation projects in North America, and arguablythe world. The mine site is characterized by an abun-dance of acid-generating rock and minerals containingtoxic metals located in an environment that rangesfrom semiarid to relatively wet at the upper elevations.The mine site contains waste rock piles that are nearly3,000 feet high at elevations that range from 6,000feet to more than 10,000 feet.

The Red River is located directly adjacent to thewaste rock piles and down gradient from the tailingsimpoundments allowing easy conveyance of pollutantsfrom the mine waste and tailings to the Red River andground water supplies. Over 3,000 acres of land havebeen disturbed by mining operations at the Questamine. Scientific studies have confirmed that significantwater quality impacts can occur as a result of contami-nated ground water emanating from the mine and millsites. In addition, steep slopes at the mine site havebeen determined to be geotechnically unstable withthe potential for catastrophic failures. Litigationaddressing residents' concern for more than one hun-dred tailings pipeline spills and tailings site seepageimpacts has been instrumental in the evolution ofMolycorp environmental management practices andNew Mexico environmental programs.

Chino and Tyrone Mines

Lore has it that the Chino mine was first revealed byan Apache Chief to the Spanish in the early 1800s as aturquoise mine. It is now owned by Phelps DodgeCorporation and has become one of the largest coppermines in North America. Some 9,000 acres (morethan 14 square miles) have been disturbed by the

The Santa Rita pit and north stockpile at the Chino mine.

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open pit mine and associated waste rock piles, leachpiles, and tailings impoundments. The site is charac-terized by a preponderance of acid-generating rockand minerals containing toxic metals, and althoughlocated in a semiarid to arid environment, has resultedin the release of significant contamination to groundand surface water. Many tailings spills have occurredin Whitewater Creek, and ground water contamina-tion is evident throughout the mine and tailings sites.

The Tyrone mine, which was not exploited until rel-atively recently, is also a massive open pit copper mine

that has resulted in more than 6,000 acres of distur-bance. It is characterized by acid generation and thepotential for toxic metals leaching from its many openpits, waste rock piles, leach piles, and tailingsimpoundments. In addition to prevalent ground watercontamination, the mine was recently cited for birddeaths at the tailings facility, leading to concern overthe potential for mortality to the southwestern willowflycatcher, an endangered species.

Other Mines

Many other mines in the state have been noted fortheir environmental impacts, including:

• The Cleveland mill site near Silver City• The Continental pit near Bayard• The Copper Flat mine west of Truth or

Consequences• The Cunningham gold mine near Santa Fe• The Asarco Deming mill in Deming• The Pecos lead-zinc mine and mill complex in

San Miguel County

• The ill-fated Earth Sciences, Inc. copper minenear Cuba

More than thirty-five uranium mines and sevenmills—two of which were designated Superfundsites—are located between Laguna Pueblo andShiprock, and the largest potash mining district in theU.S. is in southeastern New Mexico. These mines havebeen noted for a variety of ground and surface waterimpacts. In addition, mining often involves the dewa-tering of large areas, which can create long-termground water deficits and affect surface water flows aswell as seeps and springs.

MINING ENVIRONMENTAL REGULATION

The issue of mining environmental impacts and asso-ciated post-mining land use was recognized beginningin the 1960s and had been addressed, in variousforms, by most states by the late 1980s. As late as1993 New Mexico was one of two western states with-out specific legislation to address either reclamationand closure of hard rock and other non-coal mines orfinancial assurance to ensure that environmental prob-lems would be adequately addressed at the company'sexpense. (The other state without such legislation wasArizona.)

However, the problems were recognized by con-cerned citizens in mining communities, public interestorganizations, state government, and even the miningindustry itself. The various groups worked togetheractively during more than three years of negotiationsto address the problems The result in 1993 was thepassage of the New Mexico Mining Act by the statelegislature. This act provides a powerful model ofeffective mine reclamation policy.

CREATION OF COMPREHENSIVE STATE POLICY

Together with the New Mexico Water Quality Act, theNew Mexico Mining Act provides a comprehensiveregulatory process to address environmental impactsfrom mining activities. It does so through a commin-gling of the authorities of two state agencies: theEnvironment Department (enforcing the WaterQuality Act) and the Mining and Minerals Division ofthe Energy, Minerals and Natural ResourcesDepartment (enforcing the Mining Act). In the end,the process requires the applicant to obtain:

• A discharge permit from the state EnvironmentDepartment for any discharges into groundwater

The Tyrone mine’s numerous open pits, waste rock, andleach piles.



• A discharge permit (known as NationalPollutant Discharge Elimination System orNPDES) from the federal EnvironmentalProtection Agency (New Mexico has not assertedjurisdiction over surface water discharges in thestate)

• A financially guaranteed and EnvironmentDepartment-approved closure plan to assureground water protection after the end of mining

• A financially guaranteed and state-approvedcloseout plan from the Mining and MineralsDivision

The closeout/closure provisions also require the com-pany to post financial assurance to guarantee the per-formance of closeout/closure stipulations that addressmine reclamation and long-term operations and main-tenance.

The enforcement of these laws began with the adop-tion of New Mexico's innovative Ground WaterProtection Regulations, the most significant progressoccurring since the passage of the Mining Act. Morethan one hundred mine sites have been addressedusing New Mexico Water Quality and Mining Act reg-ulations, as a result of which significant dischargeshave been addressed, financial guarantees of post-mining rehabilitation established, and mined landreclaimed, protecting water resources and habitat. Thelargest mines, facing significant liabilities, laggedbehind the rest of the industry, and considerable effortby the agencies, concerned citizens, and public inter-est groups has been required to get the companies tocomply.

Finally, in 2004 nearly all the requirements hadbeen met, with closeout/closure plans and financialassurance being approved for all but a few suspendedoperations. In doing so, New Mexico has identifiedthe difficulties associated with environmental impactsand reclamation of its mines. The financial assuranceamounts for the three largest mines, which are thelargest for any mines in the U.S., indicate the enormi-ty of potential environmental impacts. Together theytotal more than half a billion dollars in potential liabil-ity. However, the situation is bittersweet: Although theliability has been recognized, it is mostly covered bycorporate guarantees rather than real financial assur-ance, and the pace of actual reclamation at the largestmine sites still lags behind public expectations.

All seven uranium mills have been reclaimed, thepotash facilities remain outside the scope of theMining Act because of a special exception, and New

Mexico has yet to effectively address most inactive andabandoned non-coal mines.

THE ENVIRONMENTAL FUTURE OF MINING INNEW MEXICO

As New Mexico moves into the twenty-first century, itstruggles to reconcile its mining environmental pastwith its future. A great deal of progress has been madein dealing with the problems recognized in the lastcentury, particularly in the past ten years. It is unclearwhether state government and particularly industryhave the resolve to face the challenges and to meet theintent of the progressive laws that were passed.

The laws that were intended to protect the state'scitizens and resources should provide these citizensthe ability to protect their air, water, habitat, and land-scapes for the foreseeable future. A critical chapter ofNew Mexico's environmental legacy of mining is cur-rently being written as mine operators seek “alterna-tive abatement standards” to allow contaminationmore severe than that allowed by regulation. The citi-zens of New Mexico have yet to tire in their quest forprotection of their water resources and other interestsand will continue to work with the present adminis-tration to address those issues.

Suggested Reading

Smith, Duane A., 1993, Mining America: the Industry and theEnvironment, 1800-1980. University Press of Colorado.

Marcus, J., Ed, 1997, Mining Environmental Handbook. Imperial College

Press.

Suggested Web Sites

www.amigosbravos.org/molycorpwatchwww.gilaresources.infowww.sric.org

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Abandoned mine lands (AML) are a complex issue, notonly in New Mexico but throughout the U.S. The fol-lowing article is intended to provide an introduction tothe problem and a look at a number of successful AMLprograms underway in New Mexico. It was compiledby Greer Price from material provided by RobertEvetts, retired AML Bureau Chief of the Mining andMinerals Division, New Mexico's Energy, Minerals andNatural Resources Department; Virginia McLemore ofthe New Mexico Bureau of Geology and MineralResources; and Melvin Yazzie of the Navajo AbandonedMine Lands Reclamation Program. Additional informa-tion on the Mines Database came from GretchenHoffman and Maureen Wilks of the New MexicoBureau of Geology and Mineral Resources.

R emediation of physical and environmental hazardsresulting from inactive or abandoned mines, col-

lectively known as Abandoned Mine Lands (or AML),is one of the greatest challenges to the mining andenvironmental industries today. Surface and subsurfaceland disturbance has created serious physical andenvironmental hazards. Accidental deaths occur everyyear at old mines across the country. Although some ofthe more than 500,000 sites in the western U.S. poselittle safety or environmental risk, there are many haz-ardous sites that should be addressed.

Historically miners went about their business muchdifferently than they do today. Exploration commonlyinvolved construction of pits, shafts, and adits that didnot yield discoveries and were abandoned. As depositswere found and developed, ore processing facilities(mills, tailings, stockpiles, etc.) were typically locatednear mine openings. Processing waste was dumpednear the processing unit, often into arroyos, rivers,lakes, or other drainages. There were no laws or otherguidelines to prevent such contamination. In bothunderground and surface mining, minimizing costswas a higher priority than safety and stability. Minesgenerally had few ventilation shafts in order to savemoney. Upon depletion of the ore, mines were oftenabandoned and mine waste and tailings piles left asthey were, without caps or vegetative cover. Suchpractices are unacceptable in today's mining industry,but the legacy of these older mines remains.

Although no complete inventory exists, it is estimat-ed that there are more than 15,000 abandoned mine

openings (shafts, adits, and pits) in New Mexico withat least 4,000 abandoned mines that have not yet beenremediated. Some of these mine features pose signifi-cant health and safety issues to the general public.Less than 10 percent of these are coal mines; the vastmajority are metal or hard rock sites. Often very littleinformation is available on these mine areas. Many ofthese sites are on public lands, where they presentpublic land managers with unique challenges relatedto accessibility and remediation.

PROBLEMS ASSOCIATED WITH AML

The hazardous effects of AML sites on the environ-ment can be broadly divided into the following inter-related and complex categories:

Land Surface Disturbances

Mining by its very nature requires disruption and dis-turbance of the land surface and/or subsurface.Topography, ore deposit type and shape, economics,and climate all play important roles in determiningmining methods and the extent of land surface distur-bance. Erosion, sedimentation, subsidence, differentialsettling of land fills and regraded mine areas, andreshaping of geomorphic features are some of the spe-cific problems that can result. Surface subsidence,such as that occurring above the underground opera-tion at Molycorp's Questa mine, is a natural conse-quence of some mining and occurs when strata over-lying underground workings collapse into mined-outvoids, typically as sinkholes or troughs.

Safety

In addition to disturbances to vegetation, wildlife, andhabitat, human safety issues associated with AML are amajor concern. There are obvious dangers associatedwith open pits and collapsing shafts and tunnels. Thereare less obvious hazards associated with abandonedmine workings, including headframes, equipment, poorquality or toxic air, and hazardous materials. In 2004there were 34 fatalities nationwide associated withabandoned mine lands, nearly all from drowning andATV crashes. Although the last death in New Mexicoassociated with an AML was in 2001 (when a highschool student fell to his death in a 200-foot deep shaft

Abandoned Mine Lands in New Mexico



near Orogrande), such fatalities andinjuries occur regularly.

Water Quality

This is primarily an issue of contaminatedrunoff from mine sites, but it can be diffi-cult to differentiate natural drainage con-ditions from those caused by mining.What we considered poor mining prac-tices today, such as dumping mine wastesinto drainages, were common in the past.Depending on the contaminants involved,their concentration and contact with liv-ing organisms, contaminated water hasthe potential to harm aquatic organismsas well as other plants and animals.Deposits that most typically causedrainage quality problems are base andprecious metals, uranium, and high-sulfurcoals, although not all such deposits pro-duce water quality problems. Many oth-ers, including some industrial mineraldeposits, can impact water quality. Themajor potential impacts of AML on waterquality include:

• Acid drainage• Metal leaching and resulting contam-

ination • Release of processing chemicals• Increased erosion and sedimentation

The New Mexico Environment Department hasidentified twenty impaired streams in New Mexico(including the Red River) potentially affected by min-ing. Various federal and state agencies plan to remedi-ate these areas, where necessary, to eliminate theimpact of AML on the affected watersheds.

Societal Effects

Often there are competing societal issues involvedwith AML sites. The urgent necessity to remediatehazardous AML sites must sometimes be balancedwith the historical significance of some sites and theirimportance to regional tourism. Mineral collecting insouthern New Mexico, for instance, is dependentupon access to inactive mines and provides muchneeded income to communities including Deming,Lordsburg, and Silver City. Some towns are particular-ly proud of their mining history and do not alwaysseek remediation of their AML sites. The residents of

Leadville, Colorado, for instance, insisted on havingmine waste and tailings piles remain. Special coverswere designed that prevent adverse water qualityimpacts but maintain the characteristic look of historicmining. The same was true for residents of Madrid,New Mexico. Some historic mines are open for tours.The Harding mine in Taos County, long inactive, iscurrently maintained as a field laboratory and mineralcollecting site.

AML PROGRAMS IN PLACE

There are a number of existing programs throughoutthe U.S. that address the remediation of AML. Theyare administered by federal, tribal, state, and localgovernment agencies and private industry. The pur-pose of such programs is to inventory historic, inac-tive, and abandoned mines, identify and prioritizehazards associated with these mines, and remediatethose hazards.

Mining districts in New Mexico. Although many of these districts areno longer active, this map provides a general idea of where abandonedmines are likely to exist.

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The primary source of funding for remediation ofAML by governmental agencies is through the SurfaceMining Control and Reclamation Act (SMCRA), signedinto law on August 3, 1977. The act established acoordinated effort between the states and the federalgovernment to fund abandoned coal mine remedia-tion. SMCRA provided funding, through a tax on cur-rent coal production, to reclaim land and waterresources adversely affected by pre-1977 coal mining.The act also allows funds to be used for remediationof non-coal mines. SMCRA only provides funding forstates (like New Mexico) that produce coal. Othersources of funding must be obtained for remediationin non-coal producing states.

SMCRA established successful AML programs incoal-producing states to achieve these purposes. Inaddition, federal agencies, Native American tribes, andthe mining industry also have successfully remediatedmany AML sites. There exists a proven record of suc-cessful mine land reclamation, hazard abatement, andeffective management of appropriated AML programfunds.

AML programs in place in New Mexico include:

The New Mexico Abandoned Mine Land Program

The New Mexico Abandoned Mine Land Program isadministered by the Mining and Minerals Division(MMD) of New Mexico's Energy, Minerals and NaturalResources Department. This is the state program thatreceives SMCRA funding, usually $1.5–2 million eachyear. Established in 1980, this program has remediat-ed over 4,000 of the most hazardous coal and non-

coal AML features in the state. By law, human safetyissues are at the top of the priority list, although envi-ronmental problems often are addressed in tandemwith safety concerns. For example, backfilling shaftsand pits with waste piles from the mine eliminatesboth features as well as their safety risk. In othercases, underground workings are left open where bats,owls, and other wildlife have taken up residence, butgrates are installed over the openings that allow accessby wildlife but not humans.

Although SMCRA allows funds to be used on non-coal sites, abandoned coal mines remain the highestpriority. New Mexico still has an estimated $10-12million worth of work to do to remediate its coal sites.These projects include hazardous mine openings, sub-sidence into old mine workings, and coal mine wastestabilization and reclamation in watershed areas.These cost estimates do not include the safeguardingand/or extinguishing of underground coal mine firescurrently burning in the Gallup, Madrid, and Ratoncoal field areas. The exact location, extent of the areaburning, potential loss to the coal resource, and costof extinguishing these mine fires have not been deter-mined but will be significant.

The program has received federal recognition threetimes in the past six years for its achievements inreclamation. Most recently, the AML program at MMDreceived the Best in the Western Region Award for2004, for the Cerrillos South Mine Safeguard Project,located 25 miles south of Santa Fe. The innovativeabandoned mine safeguarding measures in place herewere part of the development of the first park in NewMexico dedicated to mining history, the Cerrillos HillsHistoric Park. High-strength steel mesh covers withviewing platforms were installed over several shafts toallow visitors to safely view essentially untouchedmine workings. Puebloan Indians were miningturquoise and lead in this area as early as 900 A.D.,Spanish mining of lead and silver began in 1598, andfor several years in the early 1880s there was an Anglomining boom producing lead, silver, copper, and man-ganese.

The Navajo AML Reclamation Program

Native American tribes as well as states may establishAML programs and receive funding under SMCRA.From 1988 to 1992 the Navajo Abandoned MineLands Reclamation Program (NAMLRP) initiated anon-the-ground inventory assessment on non-coal-related AML sites. The Navajo Nation has jurisdiction

This grate over an abandoned mine shaft near Cerrillos allowsbats access to the underground workings but prevents humanentry. This feature is part of an award-winning AML projectaccomplished by the Mining and Minerals Division.



on Tribal Trust Lands only. In 1989 Navajo AML initiated reclamation work on

Priority 1 non-coal sites. Since then Navajo AML hassuccessfully completed approximately 90 percent ofthe 1,085 inventoried non-coal AML sites. These non-coal sites include uranium, copper, and sand and grav-el mines. The mine features include both surfacemines such as open pits, rimstrips, and trenches, andunderground mines such as portals/adits, and inclineand vertical shafts. The terrain and environmentalconditions varied widely from the low and dry landsof Cameron, Arizona, to the mountainous, rough, andwetter lands of the Chuska Mountains. Navajo AMLhas received five Office of Surface Mining awards forits reclamation efforts and numerous partneringopportunities.

After remediation of AML sites, SMCRA allows fund-ing to be used for public works projects. Navajo AMLinitiated the Public Facility Projects (PFP) Program in2000. In fiscal year 2002 they funded twenty PFP proj-ects at approximately $4.8 million. This will ultimatelyaccount for $16.2 million in completed projects.

Bureau of Land Management, U.S. Forest Service,and National Park Service

The Bureau of Land Management (BLM), U.S. ForestService (USFS), and National Park Service are respon-sible for managing most federally owned land, includ-ing remediation of AML sites. Each agency is develop-ing inventories of AML sites and, as federal fundingbecomes available, these agencies have remediatedAML sites on their lands. The USFS anticipates thatfunding will increase in 2006 for completion of inven-tory and continued remediation of sites on USFS land.The BLM estimates that 3,000 sites on public lands inNew Mexico require remediation. These federal agen-cies work closely with the state AML program.

Other programs not funded through SMCRA include:

U.S. Army Corp of Engineers RAMS Program

The U.S. Army Corp of Engineers initiated theRestoration of Abandoned Mine Sites (RAMS) in 1999to assist other agencies and industry in remediatingAML sites. RAMS funded the New Mexico Bureau ofGeology and Mineral Resources to complete an inven-tory of mines in Sierra and Otero Counties; this reportwill be released in 2005. RAMS also funded a databaseof remediation technologies. In addition RAMS is part-nering with other agencies in developing plans forremediation of sites in the Red River and Pinos Altos

areas. Funding for RAMS is federal, but separate fromSMCRA.

Industry Programs

Many mining companies have remediated AML sites.Under the 1993 Mining Act any mine in New Mexicothat had 24 months of production since 1970 isrequired to provide a plan for and implement reclama-tion and remediation. Many mining companies,including Phelps Dodge, Quivira Mining Company,Homestake Mining Company, St. Cloud MiningCompany, and Molycorp have remediated historicmines on their permitted areas and in some casesother AML near their mines. Most active mining com-panies in the state are required to have an approvedmine closeout plan, which provides for reclamation toa beneficial use after mining ceases.

REMAINING ISSUES FACING NEW MEXICO

Abandoned Mine Inventory

Most of the western states lack comprehensive inven-tories of abandoned mine sites, especially non-coalmines. In the early years of the AML programs, aban-doned coal mine areas were inventoried extensively asa requirement of the program and in satisfying thedevelopment of approved reclamation plans and theprioritization of AML projects. Historical informationregarding location, production, and ownership is gen-erally more available for coal mines than it is for non-coal or hard rock mines.

Remediation of abandoned sites involves surveying the extentof mine workings and associated hazards, as in this mine shaftnear Orogrande.

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Before New Mexico can fully address its AML issues,especially as they relate to physical hazards, it shouldhave a comprehensive inventory of all abandonedmine sites. This would include locating, classifying,prioritizing, and incorporating mine features into along-term plan for safeguarding and reclamation.Then a meaningful needs assessment can be compiledand the appropriate reclamation budgets developed.This inventory should be a multi-agency effort, usinginformation already gathered by a number of state,federal, and tribal entities.

Funding

SMCRA fee collections drive the larger AML programsand are scheduled to sunset on June 30, 2005.Congress has not yet passed legislation that wouldestablish a new fee schedule or formally extend the feecollection period. Congress did pass a continuing res-olution, which extended the established fee collectiontemporarily. Without sufficient and predictable fund-ing for the AML programs, many government agenciescannot adequately address hazardous mine features orreclaim and return AML to beneficial use. In addition,western states without coal mines do not receiveSMCRA funding.

Baseline Conditions

One of the most difficult tasks in remediating histori-cal mine sites is determining and characterizing thebaseline conditions or natural background that existedbefore mining. A knowledge of baseline conditions isnecessary, particularly in complex geologic settings, inorder to establish meaningful remediation goals.Methods that may be used for this evaluation includeintegration of historical information, published valuesof unmined, mineralized areas, analyses of water frommonitoring wells, leaching studies, statistical analyses,isotopic studies, identification of background by sub-tracting mining influences, and computer modeling.The U.S. Geological Survey has been the primaryagency to apply science to identify background condi-tions. The New Mexico Environment Department con-tracted with the U.S. Geological Survey to characterizethe baseline conditions along the Red River in TaosCounty to better understand complex interactionsbetween naturally occurring geologic features andmining-related water impacts. The paper in this vol-ume by Kirk Nordstrom outlines much of the workthat was accomplished in that study.

The New Mexico Bureau of Geologyand Mineral Resources, a service

and research division of New MexicoTech, serves as the state's geologicalsurvey. Since 1927 the bureau has col-lected published and unpublished dataon the districts, mines, pits, quarries,deposits, occurrences, and mills inNew Mexico. The bureau is convertingthat historical data into the NewMexico Mines Database, to providecomputerized data that will aid inidentifying and evaluating resourcepotential, resource development andmanagement, production, and possibleenvironmental concerns, such as phys-ical hazards, indoor radon, regionalexposure to radiation from the mines,and sources of possible contaminationin areas of known mineral deposits.These data will be useful to federal,state, and local government agencies,public organizations, private industry,

and individual citizens in order tomake land-use decisions. These dataare particularly useful in identifyingmine sites in a given area and examin-ing the potential for that mine site incontributing metals and/or other con-taminants to the watershed.

The database provides informationon the mines, quarries, mineraldeposits, occurrences, mills, smelters,mine rock piles, tailings, and pit lakeslocated in New Mexico. Altered andmineralized areas are included becausethese areas have particular importancein terms of mineral resource develop-ment and/or environmental impacts.The database will be linked to otherinformation such as geochemistry ofsamples collected by the bureau (andothers).

The data have been gathered frompublished and unpublished reportsand miscellaneous files in the bureau's

mining archive. Information on loca-tion, production, reserves, resourcepotential, significant deposits, geology,well data, historical and recent photo-graphs, mining methods, maps, andownership are included. The databasecan be incorporated with other GISlayers, including geologic maps, topog-raphy, geophysical data, remote sens-ing data, the New Mexico Geochrondatabase, and the New MexicoPetroleum database. Eventually thedatabase will be accessible via thebureau's Web page; until then thedatabase is partially available as bureauopen-file reports. Although there aremany other (and broader) applicationsfor the information contained in thiscomplex database, certainly the coop-erative development of an inventory ofAML sites in the state is one veryimportant application.

The New Mexico Mines Database


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The federal Clean Water Act was adopted in 1972with the objective of restoring and maintaining

the chemical, physical, and biological integrity of thenation's waters. The Clean Water Act is the basis ofmost national and state surface water quality standardsand regulations. Like the federal act, the New MexicoLegislature provided objectives and policy directionfor the protection of water quality when it adopted thestate's Water Quality Act in 1967. Monitoring, assess-ing, and restoring water quality are key to successfulimplementation of both the federal and state acts, andthese responsibilities are the foundation of the work ofthe Surface Water Quality Bureau of the New MexicoEnvironment Department.

The term watershed refers to the region that isdrained by a given stream, lake, or other body ofwater. It describes the area that contributes water to agiven stream or other water body. Any concern overwater quality—-or the impairment of water quality—in a given body of water must necessarily take intoaccount the health of the entire watershed. The termscatchment area and drainage basin are often used inter-changeably.

DETERMINING THAT A WATERSHED IS IMPAIRED

In accordance with the New Mexico Water QualityAct, the Surface Water Quality Bureau implements acomprehensive water quality monitoring strategy forsurface waters of New Mexico. The monitoring strate-gy establishes methods to identify and prioritize waterquality data needs, specifies procedures for acquiringand managing water quality data, and describes howthese data are used to progress toward three basicmonitoring objectives: to develop water quality basedcontrols, to evaluate the effectiveness of such controls,and to conduct water quality assessments.

As in most other states, the Surface Water QualityBureau uses a rotating basin system approach to waterquality monitoring. Using this approach, selectedwatersheds are intensively monitored each year. Thegoal is to monitor every watershed in the state at leastonce every eight years. Revisions to the schedule maybe necessary based on staff and monetary resources,


which fluctuate annually. The EnvironmentDepartment's monitoring efforts are also supplement-ed with other data collection efforts, such as USGSwater quality gaging stations, which can be used todocument long-term data trends.

Data collected during intensive surveys are used todetermine whether state surface water quality stan-dards are met and to ensure that designated uses aresupported. Assessed data are used to develop thestate's list of impaired waters (which is part of theIntegrated CWA §303(d)/305(b) Water QualityMonitoring and Assessment Report) and Total MaximumDaily Loads (TMDL).

Water quality impacts come in many forms. Impactscan be from point sources of pollution—i.e., dischargethat flows into a receiving body from a pipe or someother discrete source. Point source discharges includeeffluent from wastewater treatment plants, industrialdischarges, and storm water associated with construc-

Watershed Protection and Restoration in NewMexico—With a Focus on the Red River Watershed

David W. Hogge and Michael W. Coleman, Surface Water Quality BureauNew Mexico Environment Department

What Is a TMDL and How Is It Developed?

ATMDL, or Total Maximum Daily Load, sets an “allow-able budget” for potential pollutants by scientifically

determining through rigorous study the amount of pollu-tants that can be assimilated without causing a water bodyto exceed the water quality standards set to protect its desig-nated uses (e.g., fishery, irrigation, etc.). Once this capacityis determined, sources of the pollutants are considered.TMDLs include both point and nonpoint sources. Once allsources are accounted for, the pollutants are then allocated,or budgeted, among the sources in a manner that willdescribe the limit (the total maximum load) that can bedischarged into the river without causing the stream stan-dard, or budget, to be exceeded. Nonpoint sources aregrouped into a “load allocation” (LA) and point sources aregrouped into a “wasteload allocation” (WLA). By federalregulation, the budget must also include a “margin of safe-ty.” Thus, 100 percent of the budget cannot be allocated topollutant sources. The margin of safety accounts for uncer-tainty in the loading calculation. The margin of safety maynot be the same for different water bodies due to differ-ences in the availability and strength of data used in thecalculations.

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tion and industrial activities. Point sources are gener-ally addressed through imposition of NationalPollutant Discharge Elimination System permit limits,pretreatment requirements, management of stormwater, and other discharge management strategies.Impacts can also be caused by nonpoint sources ofpollution. Nonpoint source pollution, according to theU.S. Environmental Protection Agency, “occurs whenwater runs over land or through the ground, picks uppollutants, and deposits them in surface waters orintroduces them into ground water.” Sources are oftenindistinct, such as abandoned mines, agriculturalrunoff, erosion from denuded hillsides or stream-banks, fire scars, overgrazing or overcutting, parkinglots, recreational or paved roads, etc. Nonpointsources of pollution are generally addressed through“best management practices” and other watershedrestoration activities. Current estimates indicate thatnonpoint sources are the cause of 93 percent of thestate's surface water quality problems.

WATERSHED RESTORATION

Watershed restoration activities that address nonpointsources of water pollution are generally non-regulato-ry, voluntary initiatives that are driven by a localdesire to restore watershed health. Successful water-shed restoration efforts rely, for the most part, on thestrength of collaborative efforts to build a watershedcommunity among local residents, agencies, and otherstakeholders.

According to New Mexico's 2004–2005 IntegratedClean Water Act Report (section 303d and section305b), probable causes and probable sources of water-shed impairments include on-site liquid waste dispos-al, roads, recreation, urban storm water runoff, agri-culture, ranching, silviculture, and resourceextraction. Although no “hard” data exist, wildlifegrazing (particularly by elk) is known to also con-tribute to localized water quality problems in certainareas of the state. Grazing and habitat alteration arethe predominant sources of lake water quality impair-ment.

The implementation of treatment activities thatreduce water quality impairment has been an effectivetool in addressing watershed impairment. Treatmentsand controls for nonpoint source pollution are calledbest management practices or BMPs. BMPs can includeconstructed means of reducing impairments to surfaceand ground waters, such as inducing a more stablestream channel morphology with structures to deflectflows or installing a sewer system to replace individual

septic systems in a community. Nonstructural BMPsare conservation practices related to the way in whichwe manage our resources. The timing and rate of fer-tilizer and pesticide application, instituting stormwater management ordinances, or creating a rotationsystem for cattle grazing in areas where ground coveris critical for preventing soil erosion are examples ofthese. BMPs should realistically represent the bestcombination of structural or nonstructural manage-ment practices working together to reduce impair-ments to water quality. BMPs should be based on con-ditions of the site where the practices are to beconstructed and/or implemented and should be basedon the economics and performance targets associatedwith the specific problem to be addressed.

RED RIVER WATERSHED RESTORATION EFFORTS

The Red River Watershed is a major tributary to theupper Rio Grande in northern New Mexico. Twenty-one perennial watercourses, draining an area of 226square miles, originate as very high quality mountainstreams. The Carson National Forest manages approx-imately 90 percent of the area. Elevations range from13,161 feet at Wheeler Peak (the highest point in NewMexico) to 6,500 feet at the confluence with the RioGrande. The lowest four-mile reach of the Red Riverflows through a spectacular canyon of the Wild andScenic River Area that includes the Rio Grande gorge.The only towns within the watershed are Questa andRed River, which at an elevation of 8,750 feet is thehighest incorporated town in the state.

The Red River has long been recognized by stateand federal agencies as a high priority watershed. Itoccupies one of the most popular multiple use water-sheds in the state, devoted to recreational activities—chiefly skiing and fishing—along with widespreadlivestock grazing by U.S. Forest Service permittees.Legacy mining and exploration, as well as develop-ment, extraction, and processing of world-class miner-al deposits, are other prime features of the watershed.Concerns include: mining (primarily Molycorp, and toa lesser extent legacy mining sites in tributarydrainages); septic tank leach fields in the alluvial val-ley above the town of Red River; unlined sewagelagoons in the village of Questa; leaking undergroundpetroleum storage tanks in the town of Red River; andsediment contributed by steep, bare slopes at the RedRiver ski area and from many dirt roads, grazing allot-ments, and hydrothermal scar areas on the nationalforest.

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RED RIVER WATERSHED PROJECTS

Using Clean Water Act Section 319 grant funding, theSurface Water Quality Bureau embarked upon a seriesof on-the-ground implementation projects to addressimpacts to the watershed. These projects began in1991, and several are underway at the present time.

Beginning in 1995 the Surface Water Quality Bureauhelped to initiate the formation of a Red RiverWatershed Association. Meetings were initially held inRed River and Questa, with attendance and participa-tion by interested citizens, state and federal agenciesstaff, environmental groups, and municipal represen-tatives. Following reorganization in 1998 the RedRiver Watershed Group has continued to draw togeth-er a broad-based group of watershed residents, agen-cies, and stakeholders to take on the immense task ofrestoring conditions that will improve the quality ofwater—and therefore the quality of life—throughoutthe watershed. The group addresses a variety of waterquality issues throughout the entire drainage—fromthe headwaters to the Rio Grande—through a collabo-

rative, consensus-based approach in which every voicehas equal weight.

The Red River Watershed Group's major focus is:

• To determine pollutants, their sources and effects,and communicate the information to citizens

• To seek opportunities to enhance fish habitatwithin the watershed

• To bring citizens together to restore, protect, andfully utilize the Red River

• To educate and inform users and citizens aboutthe area and watershed stewardship

Restoration projects in the Red River Watershedhave been funded primarily through federal CleanWater Act Section 319 dollars, along with a tremen-dous effort by local volunteers and local, state, andfederal agencies. Projects initiated in the Red RiverWatershed include:


Map of Red River Watershed, Taos County, New Mexico. Impaired reaches and the pollutants of concern are shown.

58 C H A P T E R T W O


Mineral Extraction Impacts

This project was initiated in the early 1990s and wasone of the Surface Water Quality Bureau's early effortsto use passive limestone anoxic drains to intercept andtreat acid mine runoff. This first drain was installed atthe Oro Fino mine, along upper Bitter Creek.

Red River Ground Water Investigation

This project identified and addressed, via BMP imple-mentation, several forms of nonpoint source pollutionimpacting the Red River.

The Red River in the vicinity of Molycorp mine is againing stream system, recharged throughout thelength of its main stem by shallow ground water.Seeps and springs entering surface water were deter-mined to be virtual point sources of contamination,posing a sizable impairment to the Red River. The pri-mary solution implemented was to install an anoxicalkaline drain along the seep areas, which proved tobe effective in neutralizing the acidic, heavy metal-bearing seeps before they could mix with the surfaceflows of the Red River.

Lower Bitter Creek Restoration Project

This interagency cooperative pollution preventionproject was developed on lower Bitter Creek, a peren-nial-intermittent tributary to the Red River. BMPs tocontrol erosion in the stream channel, along localroads, across unstable slopes, and at the toe of anactive hydrothermal scar's landslide zone, weredesigned by the project cooperators. U.S. ForestService crews, contractors, Youth Conservation Corpsparticipants, and volunteers completed the on-the-ground work, which resulted in a measured decreasein turbidity, sediment loading, and heavy metal deliv-ery at the Bitter Creek–Red River confluence.

Enhanced Local Involvement for Addressing WaterQuality in the Red River Watershed

This ongoing effort to gain broader and more effectivelocal participation from throughout the Red Riverwatershed addresses significant water quality issues,with the goals of developing a cost-effective watershedcleanup strategy, and identifying and prioritizing sitesfor cleanup. Composed of key stakeholders, the RedRiver Watershed Group's work will address impactsidentified through the TMDL process. Strategies devel-oped will provide a framework for addressing and

reducing pollutant loading from both public and pri-vate lands.

River Park Stream Rehabilitation Project, Town ofRed River

This project is designed to address heavy sedimentloads that have caused the active Red River channel toexpand horizontally and become very shallow. A heav-ily impacted 1,500-foot section of the river is beingrestored to a more functional width/depth ratio andsinuosity using rock flow-management structures, wil-low plantings, and other BMPs. The project willincrease the river's scour energy, enabling it to trans-port its sediment load, while improving the long-termstability of the channel and bank.

Collaborative Red River Restoration Off Road VehicleImpact Remediation

This will reduce sediment and turbidity caused byunrestricted off road vehicle use by: implementing andmaintaining a series of BMPs: obliterating and reclaim-ing temporary or unauthorized roads, controlling sur-face erosion at recreation sites, managing off roadvehicle use and enforcing recreation regulations,increasing public outreach and education on waterquality protection at recreation areas, and revegetatingdisturbed areas.

Suggested Reading

Coleman, M.W., 2000, Lower Bitter Creek Restoration Project: Summaryreport for FY 94-B grant project; submitted to U.S.E.P.A., Region 6,Dallas, in completion of Clean Water Act section 319(h) project; NewMexico Environment Department, Surface Water Quality Bureau, SantaFe.

Hopkins, S., 2003, Special water quality survey of the Red River and trib-utaries, submitted to U.S.E.P.A., Region 6, Dallas, in completion ofClean Water Act section 106 grant; New Mexico EnvironmentDepartment, Surface Water Quality Bureau, Santa Fe.

Slifer, D., 1996, Red River ground water investigation: final report for FY92-A grant project; submitted to U.S.E.P.A., Region 6, Dallas, in com-pletion of CWA section 319(h) project; New Mexico EnvironmentDepartment, Surface Water Quality Bureau, Santa Fe.

State of New Mexico, 2004–2006, Integrated Clean Water Act§303(d)/§305(b) Water Quality Monitoring and Assessment Report;New Mexico Environment Department, Surface Water Quality Bureau,Santa Fe.


Acidic drainage is a common water quality prob-lem associated with hard rock metal mining and

coal mining. Acidic drainage (commonly called “acidrock drainage” or ARD) is formed when rocks contain-ing sulfide minerals come into contact with water andoxygen to create sulfuric acid, which in turn releasesmetals (e.g., aluminum, manganese, copper, zinc, cad-mium, arsenic, and lead) from the rocks. This acidicmetal-laden water can negatively impact water sup-plies used by municipalities, agriculture, or wildlife.Understanding the formation of acidic drainageinvolves the fields of geology, chemistry, and biology.However, the fundamental source of acid and metalsin the drainage is rocks, including the host rocks of amineral deposit and waste rocks resulting from min-ing.

There are several phrases used to describe wateraffected by the weathering (wearing away or erosionand chemical decomposition) of rocks in mining andmineralized areas. The term "acid rock drainage" cov-ers both mining related and naturally formed acidicdrainage, and is used in this report to emphasize thatnot all drainage affected by the weathering of rocks isrelated to mining. The term "acid mine drainage”(AMD) is limited to drainage that is both acidic andmining related. The term "mining influenced waters"(MIW) is limited to drainage that is mining related,but not necessarily acidic. This term is useful becausenot all drainage from mining areas is acidic, but non-acidic drainage may still contain significant concentra-tions of metals.

HOW DO YOU MEASURE ACID?

The pH scale is a measure of the amount of acid, withacids having pH values less than 7 and bases havingpH values greater than 7. The pH scale is logarithmic,so water with a pH value of 3 is ten times more acidicthan water with a pH of 4, and one hundred timesmore acidic than water with a pH of 5. Most naturalwaters are in the pH range of 5 to 9. Rain has a pH ofapproximately 5.7 because carbon dioxide from theair dissolves in raindrops to form a weak acid. Manyfamiliar liquids also are acidic. For example, lemon

juice and vinegar are both acidic and have pH valuesof approximately 2 and 3, respectively. Mining-influ-enced waters can have a wide range of pH values andare not always acidic. Young fish and some aquaticinsects may be harmed by pH levels below 5. The pHalso can affect aquatic life indirectly by changing othercharacteristics of water chemistry.

WHAT DOES MINING HAVE TO DO WITH ACIDROCK DRAINAGE?

One of the factors that has the greatest influence onthe production of ARD is rock type. Rocks are made ofminerals, naturally occurring chemical compoundsthat have specific crystal structures and documentedchemical compositions. Different minerals have differ-ent properties and weather differently in the presenceof water. For example, some minerals, such as halite(table salt), readily dissolve in water, whereas otherminerals, such as quartz (found in beach sand), arepractically inert (not subject to change). Various met-als are contained within the structure of these miner-als, and release of these metals into the environmentdepends on the properties of their resident minerals.

A mineral deposit is an accumulation of metals orminerals in a relatively small volume of the earth'scrust. Mineral deposits form as a result of large-scaleflow of metal-bearing fluids deep in the earth's crust.The processes involved in depositing the minerals arecollectively called mineralization. When mineralizedrock is mined, it exposes new surfaces that can be

Acid Rock Drainage

Kathleen S. Smith, U.S. Geological Survey

The pH scale, a measure of acidity, showing the pH ofsome common liquids.




WHAT KINDS OF ROCKS MAKE ACID?

Sulfide minerals are common in many types of hardrock metal mining and coal deposits. Many sulfideminerals are relatively unstable under surface condi-tions, so when they are exposed to air and water theyundergo the chemical reactions of weathering. Pyrite,or fool's gold (iron sulfide), is a common sulfide min-eral that produces acid when it weathers. The genera-tion of ARD begins with a startup reaction. For exam-ple, when pyrite comes into contact with water andoxygen (in air) the result is a reaction that producesdissolved iron and sulfuric acid (a mixture of sulfateand acid). In the acidic drainage generation cycle,once the startup reaction has begun, acid productionis self-propagating as long as pyrite, water, andmicroorganisms (bacteria) are present. The acidicdrainage generation cycle involves converting ironfrom one form (iron II) to another form (iron III).This conversion has been called the rate-determiningstep (the bottleneck) because it is slow at low pH.However, certain kinds of microorganisms can greatlyspeed up this conversion of iron by as much as 100 to1,000,000 times, especially at low pH. Once the ARDreactions have begun, conditions are favorable formicroorganisms to speed up the conversion of ironand lessen or eliminate the bottleneck in the acidicdrainage generation cycle. This is important becauseiron III can readily react with pyrite (and some othersulfide minerals) and produce more acid. In fact,weathering via iron III can produce eight times moreacid than weathering via oxygen (as in the startupreaction). So, the faster the iron can be convertedfrom iron II to iron III, the more acid can be pro-duced.

weathered and accelerates the production of ARD.Mineral deposits can be categorized into different

types, defined by characteristic minerals and associat-ed potential environmental impacts. Some kinds ofmineral deposits tend to produce very acidic, metal-laden waters, whereas others tend to produce lessacidic waters with fewer or different dissolved metals.The particular metals and minerals present in rocksand waste rock are characteristic of how that mineraldeposit was formed, and of the regional rock type,hydrology (how solutions move through the rocks),and geologic structures (such as faults). Geologic char-acterization can be very useful in predicting thepotential environmental impact and footprint (impact-ed area) of a mined site.

Several characteristics of water that are common indrainage from mining and naturally mineralized areasinclude: low pH (acidic), elevated sulfate concentra-tions, elevated iron, aluminum, and/or manganeseconcentrations, elevated concentrations of other met-als, and high turbidity, which is a measurement of theamount of small particles suspended in water. Thesecomponents commonly depend on the mineralogy ofthe deposit.

The Acid Rock Drainage (ARD) tetrahedron, showing therelationship between the four components that produceARD. All four components are required to produce ARD.



IS ACID THE ONLY PROBLEM?

The acid produced from pyrite weathering can attackother minerals in surrounding rocks. For example,acidic water can attack and dissolve common rock-forming minerals (e.g., mica and feldspar) and pro-duce dissolved aluminum. Manganese and calciumalso are common elements that have elevated concen-trations in ARD.

In mined and mineralized areas it is common to seesolid precipitates (residues) of various colors coatingstream bottoms. These precipitates can result in highturbidity, which makes the water cloudy and interfereswith sunlight penetration into the water (which inturn interferes with photosynthesis by aquatic plants).Iron forms coatings on stream bottoms over a broadrange of pH conditions, and the coatings can vary incolor from yellow, to orange, to deep red; these ironcoatings are called yellow boy. The different colors aredifferent iron-bearing minerals that form under differ-ent pH and chemical conditions; these minerals canbe used as indicators of the chemical conditions pres-ent in the stream. Aluminum forms white coatings onstream bottoms above a pH of around 5. Precipitatedaluminum may harm fish by accumulating on theirgills. Manganese forms dark brown or black coatingsat higher pHs, usually above 7. These various precipi-tates can form by natural processes in unmined areas,and their colors in stream bottoms were used as aprospecting tool by early miners to identify mineral-ized areas. Stream-bottom coatings may damage thehabitat, inhibit growth, or kill aquatic organisms thatlive on the bottoms of streams.

WHERE DO METALS COME FROM IN ACID ROCKDRAINAGE?

Trace elements (e.g., copper, lead, zinc, cadmium,arsenic, selenium) are normally present in low con-centrations in the earth's crust. However, in mineral-ized areas certain elements (depending on the deposittype) are present in above-average concentrations.Many of the trace metals in mineralized areas arefound in various sulfide minerals. Minerals that con-tain trace metals can be weathered or attacked byacidic water or iron, thereby releasing metals into theenvironment. The concentration of a released metal isa function of (1) the concentration of that metal in themineral, (2) the accessibility and susceptibility toweathering of the minerals that contain the metal, and(3) how easily the metal can be transported throughthe environment under the existing conditions.

Metals differ from organic contaminants in that theydo not break down in nature. Therefore, once metalsare released into the environment, they persist.However, metals may be affected by physical andchemical processes that can modify their transportthrough the environment. Once metals are releasedfrom their parent mineral, they can be transported bywater or sediment, precipitated, or taken up by solidparticles. Generally, metals are more easily transportedin lower-pH waters (pH less than 4 or 5), which iswhy acidic drainage usually contains elevated concen-trations of metals. However, some metals (e.g., zincand cadmium) can be transported in near-neutral pHwaters (pH 6 or 7), and some elements (e.g., arsenic,molybdenum, and selenium) can be transportedunder higher-pH conditions (pH greater than 7 or 8).

In mineralized areas and mining-related rocks, tracemetals and acid may be temporarily stored in saltsformed from evaporating mineralized solutions. Oncewet conditions return, these salts can readily dissolveto release acid and metals. Dissolved metals also maybe incorporated into solid particles; later changes inchemical conditions, such as pH, may cause the parti-cles to release these metals back into the water.

The confluence of Deer Creek with the Upper Snake Rivernear Montezuma, Colorado. As low-pH water containing dis-solved aluminum mixes with higher-pH water, the aluminumprecipitates to form a white coating on the streambed.

C H A P T E R T W O

to the size, shape, depth, and grade (richness) of theore being mined. There are two main types of mining:surface mining and underground mining. In both, asminerals are removed, rock surfaces are exposed towater and air. This presents the opportunity for acid-producing pyrite weathering reactions to proceed andproduce ARD. Therefore, openings from undergroundmines, such as adits, tunnels, and shafts, may drainARD. Warning signs of ARD near mines include red-orange-yellow coatings on rocks, dead vegetation, andgreen slime growing in discharge waters. Even thoughnot all discharges from mined areas are acidic, theymay still contain significant concentrations of dis-solved metals.

Compared to other industries, mining is unique inthat it usually discards more than 90 percent of thematerial that is processed. Therefore, there is a lot ofsolid waste rock associated with mining, and the char-acteristics of this rock control its potential environ-mental impacts. Mining-related rocks from bothunderground and surface mining may produce ARD.Once fresh rock surfaces are exposed to water and air,the minerals in the rocks can weather. Historic minesgenerally did not have the technology to efficientlyremove or isolate acid-producing minerals or metal-rich minerals from the mining-related rock. In addi-tion, mine rock piles were commonly put in the mostconvenient place for the miners, generally close to themining operation, which could be in or adjacent to astream or drainage, or at the angle of repose on amountainside. Therefore, many ARD water qualityproblems are associated with older mines.

WHAT IS OPEN-PIT MINING, AND HOW DOES ITLEAD TO PIT LAKES?

Open-pit mining is a surface-mining technique that isused when the orebody is large and relatively near thesurface. Open-pit mining involves repeated removal oflayers of rock (both ore and overburden) to form alarge open bowl-type structure. Several New Mexicocopper and gold mines were mined by open-pit meth-ods. Many open-pit mines exceed 1,000 feet in depth;therefore, most of the large open-pit mines extendwell below the ground water table. Once mining anddewatering have ceased, these open-pit mines com-monly fill with water to form pit lakes. At some point,pit lakes generally reach the point where the amountof inflow water approximately equals the amount ofoutflow water.

Pit lakes can receive inflow from both surface andground water. Ground water models predict most pit


62

HOW DO YOU REMEDIATE ACIDIC WATERS?

Most mineral weathering reactions use up acid insteadof making acid. Some minerals dissolve better thanothers or use up more acid when they dissolve. Themineral calcite (calcium carbonate), which is the min-eral that makes up limestone, is very effective at neu-tralizing (counterbalancing) acidic solutions. This isbecause it dissolves fairly easily in acidic solutions anduses up acid when it dissolves. So, calcite commonlyis used in the treatment of acidic waters. Moreover, itis a common mineral in some rocks and can neutralizeacidic waters as they flow through those rocks. Otherminerals also can help neutralize acidic solutions, butthey tend to be less effective than calcite because theydissolve more slowly.

The final pH of the drainage from mining and min-eralized areas is a balance between acid-generatingreactions (e.g., pyrite weathering) and acid-neutraliz-ing reactions (e.g., calcite weathering). The relativerates of these reactions and the accessibility of thereacting minerals ultimately determines the pH andmetal content of the drainage water.

WHAT TYPES OF MINING CAN PRODUCE ACIDROCK DRAINAGE?

Mineral deposits and the ores within them come in avariety of sizes and shapes. Therefore, methods usedto mine a particular mineral deposit must be tailored

Diagram showing how the concentration of base metals (zinc,copper, cadmium, lead, cobalt, and nickel) vary with pH innatural and mine waters. Diagram courtesy of GeoffreyPlumlee and Sharon Diehl, U.S. Geological Survey.



lakes to be terminal basins, which means that theypull in water from all sides and evaporatively concen-trate potential contaminants in the lake. During thisevaporation process, water is evaporated and contami-nants that were in the water remain behind; so, con-taminant concentrations increase because there is lesswater present to dilute them. If this is the case, andthere is no outflow from the pit lake (i.e., if it acts likea sump), then potential contaminants from the open-pit mine are contained within the lake. However, ifthere is outflow from the lake, potential contaminantsmay flow down gradient from the lake. Once a pitlake is filled, it may persist and fluctuate in elevationwith seasonal changes in weather and water flow.

The New Mexico Mines Database includes a tablelisting thirteen current pit-lake areas in New Mexico.Some pit lakes have water quality that is suitable forrecreation, such as the Copper Flat pit lake nearHillsboro, New Mexico. Other pit lakes have acidicwaters with elevated metal concentrations, such as theChino pit lake near Silver City, New Mexico. Manytechnical questions and issues remain about accurateprediction of the hydrology and water quality offuture pit lakes.

Suggested Reading

Brady, K. B. C., Smith, M. W., and Schueck, J., eds., 1998, Coal minedrainage prediction and pollution prevention in Pennsylvania: ThePennsylvania Department of Environmental Protection. Available onlinewww.dep.state.pa.us/dep/deputate/minres/districts/cmdp/main.htm

Hem, J. D., 1989, Study and interpretation of the chemical characteristicsof natural water, 3rd edition: U.S. Geological Survey Water-SupplyPaper 2254, 263 p.

Hudson, T. L., Fox, F. D., and Plumlee, G. S., 1999, Metal mining and theenvironment, AGI Environmental Awareness Series 3: Alexandria,Virginia, American Geological Institute, 64 p.

Plumlee, G. S., and Nash, J. T., 1995, Geoenvironmental models of miner-als deposits; fundamentals and applications, in du Bray, E.A., ed.,Preliminary compilation of descriptive geoenvironmental mineraldeposit models: U.S. Geological Survey Open-File Report 95-0831.

Schmiermund, R. L., and Drozd, M. A., eds., 1997, Acid mine drainageand other mining-influenced waters (MIW), in Marcus, J.J., ed., Miningenvironmental handbook: London, Imperial College Press.



Mineral resource production is vital to modern,industrialized societies. Unfortunately, mining

and mineral processing can cause serious damage towater, air, soil, and biological resources. Acid minewaters, produced from mines that extract valuablemetals such as copper, gold, silver, zinc, and lead,have damaged aquatic life, crops, and livestock. Theseproblems are not irreversible; lands and waters dis-turbed by mining can be restored, but often at consid-erable cost.

An important challenge related to mine-site reclama-tion and cost-benefit analysis is the “natural back-ground” or pre-mining water quality. The pre-miningconditions can provide a justifiable objective for clean-up goals. However, pre-mining water quality rarelywas measured at mine sites before the 1970s, andeven if it had been measured, the methods of samplecollection, preservation, and analysis were likely muchless reliable than current methods. Before 1970 detec-tion limits alone would have been higher than mostcurrent water quality standards for metals. Conse-quently, any attempt to determine retroactively thenatural background water quality at a mine site todaydepends on indirect methods using scientific infer-ence.

MINE CLOSURE REGULATIONS AND THE USGSBACKGROUND STUDY

The New Mexico Mining Act of 1993 and the NewMexico Water Quality Act (1967) require operatingmines to meet several regulations on closure. Onerequirement is that ground water must meet NewMexico ground water quality standards unless it can beshown that ground water before mining containedsolute concentrations greater than the standards. Forsuch a site, the natural background values, rather thanthe standards, may be used.

One of the largest and most productive molybde-num mines in the U.S. is operated by Molycorp, Inc.,near Questa. To provide technical information neededto help settle disputes between regulatory agenciesand Molycorp regarding pre-mining ground waterquality at this mine site, the U.S. Geological Survey(USGS) conducted a study in cooperation with the

New Mexico Environment Department. The projecthas taken more than three years (2001–2005) andinvolved an interdisciplinary team of experts in eco-nomic and environmental geology, mineralogy, geo-chemistry, hydrology, geomorphology, and geophysics.It is in the first stage of completion. To the best of ourknowledge, this study is the first to estimate pre-min-ing ground water quality for regulatory purposes at anactive mine site by a third party.

THE KEY: A PROXIMAL ANALOG SITE

The approach taken by the USGS was to study a prox-imal analog site in detail and apply the knowledgegained to the mine site. A proximal analog is locatedoff the mine site but nearby with the same geologic,hydrologic, and climatic conditions as the mine site,and whose water-rock interactions would provide aviable model for the mine site. Any substantial differ-ences between the analog site and the mine site areidentified and accounted for with appropriate modelsof water-rock interactions. The Straight Creek Basinwas chosen for the analog site (Figure 1).

During the USGS background study, there wasextensive sampling of ground waters and surfacewaters, especially a detailed chemical survey of theRed River. As the ultimate recipient of ground waterflow in the Red River Valley, the Red River waterchemistry contains clues on where ground waterenters the river, and its composition.

WATER QUALITY OF THE RED RIVER

More than one million years ago, the Red River wasthe headwaters of the Rio Grande. The Red Riverbegins at an elevation of 12,000 feet near WheelerPeak, the highest peak in New Mexico, and flows 35miles to the Rio Grande. A USGS gaging station islocated at the U.S. Forest Service Ranger Station atQuesta with hydrograph records that date from 1924to the present. Daily discharges average 46.8 cubic feetper second with a large range of 2.5–750 cubic feetper second. Areas of highly altered rock (known as“scars”) erode so rapidly that vegetation cannot be sus-tained. Acid waters occur naturally in scar areas from

A River on the Edge—Water Quality in theRed River and the USGS Background Study

D. Kirk Nordstrom, U.S. Geological Survey



the weathering of pyrite (iron sulfide).During August 17–24, 2001, the USGS sampled

water along the Red River as part of a constant-injec-tion tracer study to determine the discharge andsolute-concentration profile with distance. All majorions and several trace elements were determined onfiltered and unfiltered samples including iron, alu-minum, manganese, copper, zinc, cadmium, lead,arsenic, cobalt, nickel, molybdenum, and beryllium.These elements are of particular concern because theycan be discharged from mining activities and cancause harm to aquatic biota in the river. The analyticalresults, the most detailed chemical survey ever donefor the Red River, are available online at

http://wwwbrr.cr.usgs.gov/projects/GWC_chemtherm/pubs/OFR03_148_QuestaTracer.pdf.

One indication of the aquatic health of the RedRiver is shown in Figures 2 A, B, and C. Profiles ofdischarge, pH, and alkalinity with distance down-stream from the town of Red River are shown inFigure 2A. Note that the river flow tends to increasedown drainage, not continuously but in steps at spe-cific points in the river. The big step increase at about13,000 meters is the point at which Columbine Creekenters the Red River. The smaller increase at 6,000meters, however, has no obvious tributary entering

the river and must be from ground water inflows.Note that just upstream from the 6,000-meter pointthe discharge is decreasing; it is a “losing” streamwhere the river water is being lost to the subsurface.This loss is caused by stream flow entering the largedebris fans that push out from their respectivedrainages into the Red River and cover part of theriver. Water flowing through the debris fans emergesfarther downstream. The fans cause a “damming”effect with sediments depositing behind them.Sediments deposited behind the Hottentot fan formedthe flat valley for the town of Red River.

The pH measurements provide an estimate of theacidity or basicity of the water. Values of pH less than7 are acidic and greater than 7 are basic or alkaline. ApH near the neutral point of 7, say 6–8, is healthy foraquatic life and for human health. The pH values forthe Red River tend to be in the 7.5–8.5 range andindicate good water quality. Note, however, the dis-tinct decreases, or dips, in pH especially at the threepoints marked by the vertical dashed lines in Figure 2.These are points where acid ground waters enter. Thefirst pH dip at Waldo Springs is where naturallyoccurring acid ground waters from the Hansen,Straight, and Hottentot scar drainages enter the RedRiver. The second dip is near the Sulphur Gulch

Figure 1—Study area along the Red River Valley.

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drainage where acid waters enter from the mine site(part natural and part related to mining), and thethird dip is where acid waters enter from the Goat HillGulch area (likely natural). Both natural scar drainageand mine-waste-pile leachates occur at the mine site.However, major seeps are now being intercepted and

are no longer entering the Red River. Alkalinity is another measure of the health of the

Red River. Alkalinity is an estimate of the bufferingcapacity (or neutralizing potential) of the water; thehigher the alkalinity, the greater the capacity of thewater to resist changes in pH from acid inflows. Theprofile in Figure 2A shows a steadily decreasing alka-linity with downstream distance. Clearly the additionof acid inflows along the Red River is using up itsbuffer capacity, making it more susceptible to acidifi-cation.

Figure 2B shows distance profiles for concentrationsof dissolved sulfate, manganese, and zinc with notablestep increases at Waldo Springs, Sulphur Gulch, andGoat Hill Gulch. Sulfate is derived from dissolution ofthe mineral gypsum (calcium sulfate), which is com-mon in the Red River Valley, and from weathering ofpyrite. Only pyrite weathering, however, producesacidic waters, which can occur both naturally andfrom mine wastes. Hence, pyrite weathering hascaused some of the increases in sulfate at these stepincreases because they coincide with the same placeswhere the pH decreases occur. Manganese and zincalso have step increases in the same places as the sul-fate increases, because the minerals from which theseelements weather (rhodochrosite and sphalerite) areminerals that accompany pyrite and gypsum. Both ofthese minerals occur in the Questa ore deposit,rhodochrosite in substantial amounts. Concentrationsof most other dissolved metals in the Red River aretoo low to be of concern for aquatic health standards.

Figure 2C is a distance profile for dissolved andtotal (dissolved plus particulate) aluminum.Aluminum, derived from common rock-forming min-erals, is highly soluble in acid waters but becomesinsoluble when the pH increases to about 5. Acidinflows to the Red River are neutralized upon mixing,and a white aluminum precipitate can be seen inmany places along the banks. Consequently, the totalaluminum concentration in the river builds up as sus-pended particles, but the dissolved aluminum remainsat a low and nearly constant concentration because ofthe insolubility of this hydrous aluminum precipitateat neutral pH values.

WHEN GOOD RIVER QUALITY GOES BAD

Although the quality of the Red River is affected byacid inflows, most of the time a healthy pH and ade-quate alkalinity are maintained. Rapid, deleteriouschanges in the water quality occur when summermonsoonal rainstorms hit the valley. An example is

Figure 2— A Discharge, pH, and alkalinity with downstreamdistance in the Red River from the town of Red River to theUSGS gaging station. B Sulfate, manganese, and zinc concentra-tions with downstream distance in the Red River from the townof Red River to the USGS gaging station. C Total (dissolved plusparticulate) and dissolved aluminum in the Red River from thetown of Red River to the USGS gaging station.



shown in Figure 3 for a rainstorm event of September2002. During the early part of the rainstorm, the pHdecreased from 7.8 to 4.8, sulfate concentration dou-bled, and manganese concentration increased four-fold. Another example was recorded in 1986 thatresulted in even greater increases in acidity and metalconcentrations. These sudden changes in water qualityare caused by a surge of acid drainage that usuallycomes from natural scar areas upstream from the minesite, but which may have come from leaching of minewastes before remedial action was taken. Large quanti-ties of suspended sediment also are released duringthese high-flow rainstorm events, which can have adeleterious impact on aquatic life. Fortunately, theseare short-term changes, on the order of a few hours orless, and the river does recover. For this short dura-tion, an increase in acid inflow overcomes the buffer-ing capacity of the river, and that is why the waterquality is marginal or “on the edge.” Although waterquality in the river generally is adequate for aquaticlife, the river has little resistance to perturbations,such as rainstorms or additions of large quantities ofmine waste effluent.

CONCLUSIONS FROM THE USGS BACKGROUNDSTUDY

There is no question that in the highly mineralizedRed River Valley, acidic ground waters from scarweathering occur naturally with high concentrationsof metals, sulfate, and fluoride that can be at least ten

times greater than ground water quality standards.There is also no question that mine-waste effluent hascontributed additional acidity, metals, sulfate, and flu-oride to local ground waters at the mine site. TheUSGS study of the Straight Creek analog site, com-bined with other data collected in the Red RiverValley, is providing information that constrains pre-mining ground water concentrations and can providea baseline or reference for setting site-specific stan-dards. These pre-mining ground water solute concen-trations vary somewhat from catchment to catchment,and even within different parts of the same catchmentdepending on the geological characteristics. Hence, asingle concentration value (per constituent) for thewhole mine site probably is not a feasible approach insuch a complex and heterogeneous terrain. A range ofconcentrations per constituent and per catchment isnecessary to characterize the mine site ground watersand to allow for uncertainties in the estimate.Although these conclusions create a more cumber-some regulatory process, they reflect the realities ofthe complex geology and hydrology in this environ-ment.

Aluminum precipitation along the north bank ofthe Red River near the Molycorp mine site.

Figure 3—Change in discharge, pH, sulfate, and man-ganese at the USGS gage during the storm of September17, 2002.

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The New Mexico Environment Department is theprimary state agency regulating water quality pro-

tection at hard rock mining sites in New Mexico. Overthe last several decades there has been increasedawareness of the environmental impacts associatedwith mining operations, including contamination ofground water and surface water resources. Protectionof this water is critical, given New Mexico's limitedsurface water resources and heavy reliance on groundwater for public water supplies. Ninety percent ofNew Mexico's population depends on ground wateraquifers for drinking water, and nearly 80 percent ofthe population is served by public systems derivedfrom ground water sources. Surface water flows inmany New Mexico rivers have been significantlyreduced due to drought conditions and increasedwater demands, and New Mexico will continue to relymore heavily on ground water to sustain the state'sresidential population and business community.

The importance of the state's water resources makesthe implementation and enforcement of water qualityregulations a top priority. Mining operations are com-monly situated in complex and sensitive environ-ments, making water quality protection a challenge.Below is a summary of the water quality regulationsthat affect hard rock mining operations, as well as adiscussion of how the regulations apply to contami-nant sources, application of water quality standards,and mine closure.

WATER QUALITY LAWS AND REGULATIONSAFFECTING MINING OPERATIONS

The first water quality protection law in New Mexico,the Water Quality Act, was adopted by the NewMexico legislature in 1967. The Water Quality Actwas amended in 1973 to allow the state of NewMexico to adopt regulations requiring that permits beobtained for water quality protection. These regula-tions went into effect under the jurisdiction of theWater Quality Control Commission (WQCC) in 1977and provide the current framework for New Mexico'swater quality protection programs.

The Water Quality Control Commission regulations

include numerical standards for ground water andsurface water, and are designed to protect all groundwater in New Mexico that has a total dissolved solidsconcentration of 10,000 milligrams per liter (mg/L) orless. The regulations provide for water quality protec-tion using two methods. The first method is throughdischarge permits that prevent exceedances of numeri-cal water quality standards by controlling sources ofcontamination. The second method is through abate-ment plans that address cleanup of existing contami-nation. The Environment Department's Ground WaterQuality Bureau is responsible for administration of theWQCC ground water regulations as they apply to dis-charges from mining operations and other types offacilities.

The ground water discharge permit provisions of theWQCC regulations are the foundation of NewMexico's ground water pollution prevention programs.These provisions require that a person dischargingonto or below the surface of the ground demonstratethat the discharge will not cause ground water stan-dards to be exceeded at any place of withdrawal forpresent or foreseeable future use, and will not causeany stream standard to be violated. At mine facilitiesthe regulated discharges can include process solutions,waste rock, mill tailings, leach stockpiles, storm water,and domestic wastewater. The Ground Water QualityBureau currently has discharge permits for approxi-mately fifty mine facilities, including facilities for min-ing and/or processing of uranium, copper, molybde-num, gold, and other metal-bearing ores. The primarycomponents of each discharge permit are an opera-tional plan, monitoring plan, contingency plan, andclosure plan. The goal of the permitting process is towork cooperatively with operators to keep groundwater contaminants contained, and to ensure leaksand spills are detected early and promptly remediated.

The state of New Mexico also works closely with theU.S. Environmental Protection Agency (EPA) in imple-menting the federal Clean Water Act, Safe DrinkingWater Act, and other federal laws that address waterquality protection. In particular, the EPA administersthe National Pollutant Discharge Elimination System(NPDES) permit program that is applicable to mining

Water Quality Regulation of MiningOperations in New Mexico

Mary Ann Menetrey, New Mexico Environment Department



operations pursuant to the Clean Water Act. TheseNPDES permits are intended primarily to protect sur-face water quality and address point source dischargesto surface waters. The Environment Department'sSurface Water Quality Bureau coordinates with EPA inadministering the NPDES program by certifying per-mits, conducting inspections, and providing permitinformation to the public and operators. The SurfaceWater Quality Bureau is in the process of obtainingprimacy for the NPDES program, which will allow thestate to issue NPDES permits to mining and otherfacilities. Nonpoint source contamination at mine sitesis addressed through implementation of best manage-ment practices and storm water controls.

SOURCES OF GROUND WATER AND SURFACEWATER CONTAMINATION

Ground water and surface water contamination haveoccurred at many mining operations throughout thestate. Although the sources of this contamination vary,some of the primary contributors include acid rockdrainage from sulfide-bearing ore and waste rock, aswell as process solutions that have escaped fromunlined leach stockpiles and tailing impoundments.Much of the existing contamination from mining facil-ities is a result of past disposal practices that wouldnot be permitted under the current regulations.Recently issued permits have focused on more rigor-

Mines with ground water discharge permits in New Mexico.

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ous contamination prevention measures, such as lin-ing of leach stockpiles and establishing waste rockmanagement plans to reduce the potential for acidrock drainage.

Metals are the primary contaminants at mine sitesaffected by acid rock drainage. These metal contami-nants include aluminum, copper, cadmium, arsenic,chromium, fluoride, and zinc. This contamination is aresult of acidic solutions releasing metals containedwithin stockpiled rocks or tailings exposed to waterand oxygen. Acidic solutions are intentionally appliedto ore piles at some of New Mexico's copper mines tospeed up this acid rock drainage process that dissolvescopper so that it can be removed for processing. Totaldissolved solids and sulfate are also common contami-nants, often found as a precursor to metal contami-nant plumes or associated with mine wastes that lackthe potential for acid generation.

Open pits associated with mining operations canalso be a source of water quality degradation. To facili-tate mining, many large open pits have been minedbelow the ground water table, and dewatering opera-tions are necessary to keep the pits dry. Where thewalls of these pits contain sulfide-bearing minerals,oxidation of these minerals causes the release of metalcontaminants into surface runoff waters that can accu-mulate in the pit bottoms. When mining ceases anddewatering of the pits stops, ground water flow backinto the pits can create pit lakes that exceed surfacewater standards for many contaminants.

APPLYING WATER QUALITY STANDARDS ANDABATEMENT

Once ground water or surface water becomes contam-inated, cleanup can be very challenging and costly.Many mine facilities are located over fracturedbedrock, where it is difficult to install extraction wellsto recover the contaminated water. Contaminatedwaters move through these fractures and can eventual-ly migrate into aquifers that provide a current orfuture water supply, or they can enter surface waters.Additionally, tailing impoundments and leach stock-piles often contain very large volumes of residualprocess solutions that can take decades or longer tocompletely drain from the piles. Where these facilitiesare unlined and water has become contaminated, it isalmost impossible to prevent this drainage from con-taminating underlying ground water for years to come.

The Water Quality Control Commission has deter-mined that most ground water in New Mexico with atotal dissolved solids or TDS concentration of less

than 10,000 mg/L, including the ground water direct-ly underlying mine facilities, has a reasonable andforeseeable future use. Therefore, the ground waterunderlying tailings, leach stockpiles, and other minesource areas must be cleaned up to water quality stan-dards if it becomes contaminated. Contaminated waterbeneath these facilities cannot be left unabatedbecause ground water can migrate away from thesefacilities and contaminate nearby water supplies. Also,many mine sites are candidates for future industrial orresidential development, and in either case will need aclean on-site water supply.

The Water Quality Control Commission recognizedthat there might be situations where it is not techni-cally or economically feasible to fully abate contami-nation of ground water. The WQCC regulationsaddress these situations by including provisions foroperators to petition the WQCC for approval of alter-native abatement standards (AAS), which are a type ofvariance from the numerical ground water qualitystandards. In order to obtain alternative abatementstandards the petitioner must demonstrate that:

• compliance with the applicable WQCC groundwater standards is not feasible or there is no rea-sonable relationship between the economic andsocial costs and benefits;

• the proposed AAS are technically achievable andcost-benefit justifiable; and

• compliance with the proposed AAS will not cre-ate a present or future hazard to public health orundue damage to property.

Pit lake at Nacimiento open-pit copper mine near Cuba.



The Water Quality Control Commission hasapproved alternative abatement standards for twomine sites in New Mexico, including the L-Bar urani-um mill site in Cibola County and the CunninghamHill mine in Santa Fe County. The EnvironmentDepartment was able to support the AAS petitions forboth these sites because, in part, the mine operatorshad conducted extensive ground water abatement,characterization, and source control measures beforesubmitting their petitions. Given the difficulties ofcleaning up existing contamination at many othermine sites, the Environment Department anticipatesthat there will be several more AAS petitions comingbefore the WQCC in upcoming years.

Another important consideration regarding groundwater cleanup at mine sites is the issue of backgroundconcentrations. Many mine operations are situated inmineralized areas where ground water may be natural-ly elevated in concentrations of total dissolved solids,sulfate, or certain metals. Under the abatement provi-sions of the WQCC regulations, where the back-

ground concentration of any contaminant exceeds thenumerical ground water standard, the responsible per-son can abate to the background concentration ratherthan numerical standards. However, determining thebackground concentration can be extremely compli-cated at mine sites where the geology is complex andthere are multiple aquifers. Due to site-specific differ-ences, the Environment Department does not believeit is appropriate to establish a single method for deter-mining background concentrations. Background con-centration investigations are ongoing at several minefacilities, including the Molycorp Questa mine, wherethe U.S. Geological Survey has been conducting abackground investigation since 2001.

WATER QUALITY PROTECTION FOLLOWING MINECLOSURE

One of the greater challenges facing state regulatorsand mine operators is determining adequate closuremethods for existing operations after mining opera-

Seepage into the Red River at Spring 39 adjacent to the Molycorp mine site.

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tions cease. In addition to the long periods needed fordrainage of process solutions, acid rock drainage atsome facilities is predicted to continue for decadesand possibly centuries. Under the WQCC regulations,ground water discharge permits must include closureplans to ensure that water quality standards are metafter the mine operation shuts down. The componentsof the closure plan are a description of closure meas-ures, maintenance and monitoring plans, post-closuremaintenance and monitoring plans, financial assur-ance, and other measures necessary to prevent andabate contamination.

The Environment Department has consistentlyrequired that closure plans for mining operationsfocus on enacting source control measures to reduceor eliminate ongoing contamination of ground waterand surface water after operations cease. Containmentof contamination without source controls would notmeet WQCC requirements and is not practical forsites where contamination could continue for decadesor centuries. Measures that are typically included inmine closure plans approved by the EnvironmentDepartment include long-term stabilization measuressuch as regrading of stockpiles and erosion controls,covers over stockpiles and tailings that minimize infil-tration into contaminated material, and a plan forlong-term water treatment of contaminated groundwater and surface water.

Due to the large size of some mining operations andextent of existing contamination, there is uncertaintyas to whether approved closure measures will success-fully protect water resources; therefore, manyapproved closure plans also include requirements foradditional studies to refine the closure plan and allowthe mine to plan better for closure. Examples of addi-tional studies include test plots, stability studies,hydrologic investigations, and feasibility studies.Approximately thirty studies related to site closure arecurrently underway for the Molycorp Questa mine. Asmore data are collected in the area of mine closure, itis anticipated that permitting for closure under theWater Quality Control Commission regulations shouldbecome both more effective and more efficient.



Mining in New Mexico has been going on for hun-dreds of years. During this time the public's per-

ception of the concepts of environment, water, eco-nomics, and sustainable development has changed. Ahundred years ago, mines were not planned, operated,or reclaimed according to today's standards. Morerecent operations that were planned or operated with-out sustainable development in mind now are chal-lenged by regulatory requirements to reclaim to a sta-ble landform. With the passage of mining legislationsuch as the New Mexico Mining Act in 1993 and theSurface Mining Control and Reclamation Act of 1977(SMCRA), new mining operations in New Mexico arerequired to integrate planning, operating, and reclaim-ing activities with a specific post-mine land use inmind. For this reason, the major engineering chal-lenges must be viewed in the context of the age of theoperations, and reclamation standards that havechanged over time. The New Mexico Mining Act dis-tinguishes between “existing units” and “new units”when applying reclamation standards. Some engineer-ing challenges are unique to older sites. Newer sitescan be planned from the beginning to accomplish sus-tainability of the post-mine land use. Some of themajor engineering challenges include:

• Slope stability and reclaiming mined land tolandscapes that are geomorphologically stable andself-sustaining

• Design of operations and reclamation strategies tominimize negative public perception issues

• Reclaiming mine sites to geochemically stabilizeland without impacting water quality

SLOPE STABILITY

Landforms in New Mexico consist of hills and valleys,mesas and arroyos, mountains and canyons, which areall ways of referring to low areas and high areas.Slopes at various angles connect the low and highareas to each other. Slopes are never completely stablebecause of the effects of gravity and erosion, which areconstantly trying to create a flat environment. We've

all had some experience with slope stability workingin our yards or in a sand pile, and we can understandthat we can stack some materials higher and steeperthan other materials. The steepest angle at which apile of material will stand is referred to as the “angleof repose.” All materials have an internal resistance orfriction. The higher the internal resistance, the betterthe material's ability to resist the effects of gravity.Materials with higher internal resistance will have asteeper angle of repose, and different materials havedifferent angles of repose. For any material, though,the lower the slope angle, or said another way, theflatter the slope, the more stable the slope.

When we discuss slope stability at mining opera-tions, we are generally referring to the reclaiming ofmined landscapes to be geomorphologically stable.Geomorphologically stable means creating a stabletopography that soil, slope, and weather would natu-rally form over time, similar to the natural landform.Mining regulations now require that mine reclamationcreate a self-sustaining ecosystem that includes thephysical stability of the landscape. This has not alwaysbeen the case. As a result, some older mines havebeen abandoned and left with unstable slopes. Someactive mines must now reclaim unstable slopes thatwere created before mining regulations required suchreclamation.

Engineering Challenges Related to Mining andReclamation

Terence Foreback, Mining and Minerals DivisionEnergy, Minerals and Natural Resources Department

Successfully reclaimed mined land in New Mexico duringthe second growing season.

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So what types of slopes are we talking aboutreclaiming at mining operations in New Mexico?

• Slopes on spoils (in-pit waste rock) at coal mines

• Slopes on out-of-pit waste rock piles at open-pit metal mines (i.e., Tyrone)

• Slopes on tailings dams

• Any slope that was created or affected by the mining operation that must be reclaimed

Slopes on Spoils at Coal Mines

Reclamation of spoil at coal mines involves restoringnatural vegetation and drainage in order to return themine site to a self-sustaining ecosystem such as farm-land, wildlife areas, parklands, or housing develop-ments. The reclamation process actually begins beforethe first ton of coal is removed. To fulfill mining per-mit requirements, the coal company must documenthow sedimentation from the temporarily disturbedareas will be controlled, how ground and surfacewaters will be protected, and how restoration of thesoil and vegetation will be achieved.

Fluvial geomorphic-based design of post-miningtopography is an engineering technique that is beingused at mining operations in New Mexico. The endproduct of fluvial geomorphic-based design is a post-mining topography that resembles the natural sur-roundings. The reclamation grading and recontouringgoals of fluvial geomorphic-based design are:

• To provide long-term stability for steep slopes and drainages

• To increase topographic diversity to improve habitat for plants and wildlife

• To reduce the potential for flash flooding of adja-cent property as compared to the pre-mine con-ditions

• To create a functional landform that blends in with the surrounding natural terrain

The fluvial geomorphic approach creates a stabletopography similar to what the combination of soil,slope, and weather would naturally form over timeand includes sinuous drainage systems that mimicsurrounding terrain. Channel dimensions are designedto pass the storm discharges that would be expectedfrom a yearly maximum storm event and to pass the

sediment from these annual flow events. These chan-nels are also designed to pass larger events withoutexcessive erosion by allowing overbank discharges tospread out over a flood-prone area as would naturallyoccur.

San Juan Coal Company, a New Mexico miningoperation, received the 2004 federal Office of SurfaceMining's National Award for Excellence in SurfaceCoal Mining, Best of the Best Award for its applicationof fluvial geomorphic-based techniques. Althoughthis procedure has been pioneered at New Mexico'scoal mines, it can be applied to other types of mineswhere conditions allow.

Slopes on Out-of-Pit Waste Rock Piles at Open-PitMetal Mines

When open-pit metal mines remove non-economicmaterial overlying an orebody, the material must beplaced somewhere out of the way of the mining oper-ation. This out-of-pit material is referred to as wasterock. Waste rock piles can vary in size depending onthe mining operation, but some waste rock piles canbe quite large.

Waste rock piles in the past were placed in the mostconvenient location determined solely on economics.They were typically dumped at their angle of reposeon pre-existing hillsides near the mining operation.Sometimes these hillsides were not stable. In somelocations waste rock was deposited on material thattrapped ground water flowing through the waste rockpiles or contained clay and developed into a slidingsurface. These factors have all contributed to unstable

Overview of Cottonwood pit reclaimed topography in theforeground and undisturbed topography in the distance.Reclamation work is shown prior to revegetation.


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waste rock piles that now must be addressed.Mitigation of the waste rock piles that were notdesigned to be geomorphologically stable is difficult.Mitigation is a process of lessening (reducing) theslope of the pile, combined with ensuring adequatedrainage.

There are two ways to reduce the slope of a wasterock pile. Earthmoving equipment can start at the topand extend the toe of the stockpile in length, thus cre-ating a flatter surface. If this is not possible because ofconstraints such as highways, topography, structures,streams, or environmental concerns, then the materialmust be removed starting at the top and placed inanother location.

Ensuring adequate drainage lessens the effects ofsurface and sub-surface water. Constructing surfaceinterception ditches can reduce infiltration by prevent-ing surface water from flowing onto rock piles and bypreventing ponding of water on rock piles. Mitigationof ground water effects is difficult on rock piles thatwere not properly engineered.

Waste rock piles at new operations can be designedto be geomorphologically stable. Slopes can be con-structed at an angle much less than the angle ofrepose. Rock pile locations can be selected so thatmaterial is not placed on areas that are already unsta-ble. Drainage under rock piles can be established byconstructing gravel underdrains that can prevent thebuildup of ground water pressures. Surface drainagecan be designed to prevent any ponding of water onrock piles, and diversions can carry water away fromthe pile.

Many mining operations can also be designed toplace some or all of the waste material back into theopen pit. The advantages of partial backfill are possi-ble reduction of disturbed area, containment of wasterock piles, and partial reclamation of the open pit.The backfilled material can then be graded asdescribed above in order to achieve stability.

Slopes on Tailings Dams

Tailings dams are man-made structures used to con-tain the non-ore material that is left after ore isprocessed. Typically, this waste material is very fineand has a high moisture content.

The same types of considerations discussed aboveapply to slopes on tailings dams. The major engineer-ing design difference is that tailings dams are struc-tures containing large volumes of material consistingof water and very fine material created during the pro-cessing of the ore. The slopes on the tailings damsmust be not only geomorphologically stable, but thedam must hold back material that has low internalstrength. For this reason, the state of New Mexico hasregulations and standards on the design and construc-tion of these structures.

Other Slopes at Mining Operations

There are other types of slopes at mining operationssuch as slopes on leach stockpiles. Current regulationsrequire that these slopes be designed to be geomor-phologically stable upon reclamation. The guiding


Grading waste rock piles to obtain more stable slope angles.

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principles for the engineering design are creating flat-ter slopes and ensuring adequate drainage.

DESIGN TO MINIMIZE NEGATIVE PUBLICPERCEPTION ISSUES

Public perception issues related to mining are oftenthe concerns most frequently dealt with by regulatorsand legislators in New Mexico. These concerns arerelated to how the public comes into contact withmining issues such as:

• Dust from mining operations

• Blasting and its effects

• Traffic from mining operations, particularly fromtrucks

• Visual effects

Mining operations usually cannot eliminate theseeffects, but mines can be planned, operated, andreclaimed to minimize them.

Dust from mining operations can be controlledthrough a variety of engineering practices. Roads canbe designed using materials that create less dust.There are environmentally friendly substances that canbe applied to road surfaces to suppress dust. One ofthe simplest procedures is to apply water to the roadsurface. Mineral processing plants can use cyclones orother collection methods to capture dust rather thanemitting it to the atmosphere.

Mining operations where blasting is performed canuse blasting techniques that minimize its effects. Usingblast delays that reduce the amount of explosives thatare shot at one time can greatly reduce the effects ofground vibration. Reducing ground vibration caneliminate damage beyond the mining property bound-ary and minimize the perception of damage. Usingblasting methods that reduce noise can greatly influ-ence the public's perception of blasting. Proper plan-ning, design, and operations can greatly reduce thepublic's perception of the consequences of blasting.

Traffic from mining operations almost always createspublic perception issues. Usually the issue is truckscarrying the mined material, and the problem is par-ticularly evident with aggregate (sand and gravel)operations. Solutions to this problem may be solicitedin public meetings with affected stakeholders andcould include minimizing dust from roads, carefullyplanning the hours of operation, monitoring the speedand size of the trucks, and minimizing (to the degree

possible) the number of trips by processing on site.Visual effects are often a concern to the public. But

mines can be planned, operated, and reclaimed tominimize visual effects. Operations can be planned tominimize the amount of surface disturbance by min-ing only the required area to meet production require-ments and by reclaiming areas expeditiously aftermining. Planning should be given to the permanentmine facilities relative to their siting. Proper reclama-tion techniques previously discussed, such as fluvialgeomorphic-based design, can also create a post-mineenvironment with a pleasing visual effect.

RECLAIMING MINE SITES TO GEOCHEMICALLYSTABLE LAND WITHOUT IMPACTING WATERQUALITY

Another engineering challenge is reclaiming mine sitesto be geochemically stable without impacting waterquality, specifically:

• Soil problems related to coal mines

• Acid rock drainage from waste rock piles

• Soil problems related to reclaiming areas with low pH and high metal content.

To a large degree, if a mine is not reclaimed to begeochemically stable, it will not be geomorphological-ly stable.

Soil Problems Related to Coal Mines

Two major problems encountered during coal minereclamation are salinity and clay content of topsoiland spoil material. Reclamation at some mines in NewMexico was problematic because vegetation could notbe established in soils that contained a high salt andclay content. Regulations now require that mine oper-ators sample the available topsoil material before min-ing. Both quality and quantity of the material must beaddressed to ensure that both are adequate for recla-mation. The material that will be mined must also beanalyzed for problems in soil chemistry, which mustbe taken into account prior to reclamation.

Acid Rock Drainage from Waste Rock Piles

Waste rock piles may contain materials that createacid drainage. This usually is caused by water reactingwith waste rock of material containing the mineralpyrite. The water flows through the rock pile, reacts



with the pyrite, and then flows out of the rock pile asacidic ground water. Acidic water can dissolve metalsand other substances and may contain unacceptablyhigh levels of these contaminants. The acid rockdrainage (ARD) can remain beneath the surface, caus-ing contamination of ground water, or surface assprings and contaminate surface water.

The effects of ARD from rock piles can be mini-mized, particularly when mining operations plan,operate, and reclaim with mitigation in mind. Surfacewater can be diverted around rock piles to minimizethe amount of water that will infiltrate into the pile.Soil layers placed on top of the rock piles can beproperly designed and vegetated to use the precipita-tion that naturally falls on the rock piles withoutallowing infiltration. This is referred to as a “store andrelease cover.” In extreme cases, systems can bedesigned and constructed to collect ARD that flowsfrom rock piles so that it can be pumped and treated.

Soil Problems Related to Reclaiming Areas with LowpH and High Metals Content

Metal mining operations sometimes have unique engi-neering challenges reclaiming areas with low pH (highacidity) and high metals content. Two areas usually ofconcern are tailings areas and waste rock piles. Thereare several challenges with ensuring that proper engi-neering is done in these areas including:

• Limiting water infiltration and ARD by establishing a store and release cover.

• Ensuring that neutral cover material is placedover material that would inhibit plant growth. The concern here is that plants may not growadequately in the acidic material or they may absorb metals through the roots.

• On areas that were not regulated and designed according to current standards, interceptor sys-tems for ARD may need to be constructed after problems have been encountered.

REQUIRING ADEQUATE FINANCIAL ASSURANCE

Mining has left an unfortunate legacy of abandoned,unreclaimed sites in New Mexico. For this reason theNew Mexico Mining Act and the Surface MiningControl and Reclamation Act require that miningcompanies calculate the cost of reclamation and post abond for that amount in the event the companybecomes insolvent and cannot meet its regulatoryresponsibilities.

The calculation of the cost to reclaim is an impor-tant engineering challenge. Engineers working on thecalculation must have an adequate understanding ofthe principles of reclamation. There must be regulato-ry oversight of the calculation in order to ensure thatadequate reclamation funding is available. This is oneof the most important engineering challenges and onethat ensures that unreclaimed sites will not be an issueof the future.

Conceptual design of an acid rock drainage collection system.



Our nation's infrastructure—streets, highways andbridges, houses and buildings, sidewalks, sewers,

power plants, dams, just about everything—requireshuge volumes of aggregate. The main sources ofaggregate in the United States are sand and gravel (43percent) and crushed stone (57 percent). These mate-rials are commonly used with a binder in concrete,mortar, and blacktop. About 2.66 billion metric tonsof natural aggregate worth $14.5 billion (exceedingthe total value of all metals) were produced in theUnited States during 2003.

Many agencies advocate that resource extraction besustainably managed. This approach commonlyrequires that decisions regarding resource extractioninclude best management practices and other environ-mental management tools that consider health, eco-nomic prosperity, and social well-being.

Most aggregate is used in its natural state, exceptperhaps for crushing, sizing, and washing. Unlikemost metallic resources, aggregate is not concentratedfrom an ore. Quality aggregate is chosen specifically toavoid metallic and other minerals that react withwater to create acid.

Because aggregate is expensive to transport, it isquarried near the point of use, commonly a popula-tion center. Resource availability and conflicting landuse issues severely limit areas where aggregate can bedeveloped. The siting of aggregate quarries dependsprimarily upon where the geology is favorable and notnecessarily where it is needed most.

Most environmental impacts from aggregate quarry-ing are benign. The impacts are generally close to thequarry and can be largely mitigated. Impacts frommost extraction activities relate to the geology of thesite, and geologists can help identify impacts anddesign plans to avoid them. Aggregate production mayalter geologic conditions, altering the dynamic equilib-rium of the site. Specific impacts and their mitigationare outlined below.

CONVERSION OF LAND USE

The most obvious environmental impact of pit/quarryoperations (which is what most aggregate “mines”consist of) is the conversion of land use, generally

from undeveloped or agricultural lands. Surface pitsand quarries are dramatically different from mostother land uses. Careful selection of a pit or quarrysite minimizes the amount of surface area that must bedisturbed by resource extraction. In some cases, thepost-quarry use is more acceptable to the public andmore environmentally or economically valuable thanthe original, pre-quarry use.

Conversion of land use may impact features of spe-cial interest or significance. Conducting a pre-quarryinventory of the site for scenic, biological, historical,archaeological, paleontological, or geological featuresminimizes this impact. Ironically, such features aresometimes recognized as unique only when aggregateoperation begins. Aggregate extraction uncovers a rela-tively large area at a relatively slow pace, which canlead to serendipitous discoveries to which manyorganizations are able to respond rapidly.

CHANGE TO VISUAL SCENE

Conversion of land use often changes visual character,viewed either from the site or toward the site. Thechange, temporary or permanent, is subjective; what isacceptable to some is objectionable to others. Visualimpact depends on the topography, ground cover, andthe nature of the quarry operations.

Visual impacts can be mitigated through carefulquarry planning and design. The process may includelimiting extraction areas and unnecessary disturbance(such as road widths), staining fresh rock faces to

Environmental Impacts of Aggregate Production

William H. Langer, U.S. Geological SurveyL. Greer Price and James M. Barker, New Mexico Bureau of Geology and Mineral Resources

Sand and gravel production for the year 2003, and sand andgravel as a percentage of the total aggregate production bystates in the New Mexico region and for the United States.

STATE SAND & GRAVEL SAND & GRAVEL ASPRODUCTION A % OF AGGREGATE

(103 metric tons) PRODUCTION

Arizona 59,800 84.8 Colorado 33,500 73.0 New Mexico 13,900 77.0 Oklahoma 9,890 17.3 Texas 81,500 43.5 Utah 26,100 77.3 United States 1,140,000 42.9



resemble weathered rock, creating buffer zones, andvisual screening such as berms, tree plantings, fencing,or using other landscaping techniques. Overburdenand soil can be stockpiled out of view. Good house-keeping practices, such as maintaining equipment andlocating equipment below the line of sight or inenclosed structures, are also effective.

LOSS OF HABITAT

Site preparation often results in loss of habitat forsome species. Pre-production site inventories identifyrare or endangered species so that habitat can be setaside, or so that extraction operations can be suspend-ed during critical breeding or migrating seasons.Creation or improvement of habitat off site can offsetthe loss of habitat on site. Selected animals or plantscan be relocated. After closure, the site may bereclaimed to look and function like the original habi-tat. Reclamation during quarrying, rather than waitingto the end of operations, can speed habitat recovery.

Many aggregate operations preserve existing habitatthrough creation of buffer areas. The buffer areas ofmany aggregate operations retain all the characteristicsof the original habitat or may be planted to increasevegetative cover. In some populated areas, quarrybuffers are a significant part of the total available openspace. Wildlife from the surrounding area may seekthe protection afforded by such buffers. Some activeaggregate operations and their buffer zones can serveas habitat for rare or endangered species. Water is amajor limiting factor in arid and semiarid climates.Irrigation may be necessary to establish new vegeta-tion.

NOISE

The most frequent complaint from the public aboutaggregate operations is noise. Tolerance to new noisedepends upon the background noise to which one hasadjusted. In an urban or industrial environment,background noise may mask noise from an aggregateoperation. In contrast, the same level of noise from anoperation in a rural area or quiet residential neighbor-hood is noticeable to those accustomed to quiet set-tings.

Ambient noise generally is an accumulation thatdoes not have a single, identifiable source. If noise canbe identified as coming from a quarry, the perceptionof this noise may be enhanced. Noise impacts arehighly dependent on the sound sources, the topogra-phy, land use, ground cover, and climate. Sound trav-

els farther in cold, dense air and during atmosphericinversions.

The primary sources of noise during aggregateextraction are engines, processing equipment, andblasting. Aggregate producers are responsible forensuring that the noise emitted from the pit or quarrydoes not exceed regulated levels. Regular inspectionsand maintenance can help ensure effective noise con-trol for equipment.

Noise generated during quarrying can be mitigatedthrough various engineering techniques. Topography,landscaping, berms, and stockpiles can form soundbarriers. Noisy equipment (such as crushers) can belocated away from populated areas and can beenclosed in sound-deadening structures. Conveyorscan be used instead of trucks for in-pit movement ofmaterials.

Trucking of aggregate is a significant source of noise.The proper location of access roads, the use of acceler-ation and deceleration lanes, use of engine-brake muf-flers or avoidance of engine-brake use, and carefulrouting of trucks all can reduce this noise or at leastits detection. Noisy operations can be scheduled orlimited to certain times of day.

DUST

The impact of dust is determined by proximity of theoperation to residential areas, ambient air quality,moisture, air currents and prevailing winds, the size ofthe operation, and interaction with other dust sources.Regulations strictly limit the amount of dust emittedduring quarrying. A carefully prepared and imple-mented dust control plan reduces impacts. Controll-ing fugitive (non-point source) dust commonlydepends on good housekeeping more than on elabo-rate engineered controls. Techniques of dust controlinclude applying water and chemicals to haul roads,sweeping, reduced vehicle speed, windbreaks, andground cover. Point source dust can be controlledusing dry or wet suppression equipment. Dry sup-pression includes conveyor covers, vacuum collectionsystems, and bag houses. Wet suppression systemsconsist of pressurized surfactant-treated water spraysthroughout the plant. Lack of an adequate water sup-ply can present a problem for large operations in thearid west and thus water is often trucked or pipedlong distances.

BLASTING

Quarry blasting may occur daily or as infrequently as

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once or twice a year. Potential impacts include groundvibrations, noise, dust, and flyrock. Geology, topogra-phy, and weather all affect the impacts of blasting.Buffer zones, tree belts, and berms may serve multiplepurposes in reducing noise and dust levels betweenthe mine site and community, while improving thevisual quality of the area.

The modern technology of rock blasting is highlydeveloped, and when blasting is properly conducted,the environmental impacts should be negligible. Byfollowing widely recognized and well-documentedlimits on ground motion and air concussion, directimpacts are mitigated.

CHEMICAL SPILLS

Routine equipment maintenance and blasting mayresult in the accidental spillage of solvents, fuels, andblasting agents, which can contaminate surface orground water. Leaking underground storage tanks canpollute ground water. Minimizing chemicals used,properly storing all hazardous chemicals and petrole-um products carefully within bermed areas, monitor-ing water for nitrates, and providing workers withtraining in safe operation and maintenance proceduresare all part of best management practices.

GROUND WATER

Predicting the environmental impacts of these opera-tions on ground water is highly dependent on anunderstanding of local geology, hydrology, and cli-mate. Precipitation may flow into a quarry andrecharge ground water. In dry climates, evaporation ofwater in pits or quarries may actually lower the watertable. Removing vegetation from the quarry reducesevapotranspiration, which may ultimately increaseground water. In highly permeable deposits, imperme-able subsurface (slurry) walls are sometimes necessaryto isolate the pit from the water table. Water removedfrom pits through pumping can be returned to nearbystreams, which may recharge the ground water supplydownstream.

In some areas of aggregate production, changes inground water quality have been attributed to theremoval of soil that previously acted as a protectivelayer that filtered or otherwise reduced contaminantsreaching the ground water. Many heavy metals, easilydegraded organic substances, and bacteria are retainedrelatively well in the natural soil layer. If an underly-ing gravel layer is exposed, this retention is muchweaker. The level of impact depends on the thicknessand character of material removed, the surface areainvolved, and the total volume and recharge of theaquifer. Impacts can be mitigated by controlling waterrecharge in quarries or by locating quarries outside ofrecharge areas.

SURFACE WATER

Aggregate operations entail removal of vegetation thatmay retard runoff. Aggregate extraction may createimpervious land that prevents infiltration or maychange runoff patterns in other ways. Pits and quar-ries may affect surface water chemistry, but these sub-tle changes are primarily local. The ability to predictflooding and deposition at a pit or quarry largelydepends on how well the hydrology and history of theadjacent stream and surrounding watershed areknown.

Water from aggregate processing and storm runoffover pit/quarry sites can increase the suspended rockparticles (turbidity) in stream runoff. Turbidity is gen-erally greatest at pit/quarry and wash-plant water dis-charge points and decreases downstream. Turbiditycan be controlled by filtering, or by containing runoffor wash water at recharge basins.

Aggregate production within stream floodplains mayimpact stream-channel morphology. Flooding streams

Aerial view southward of the Taos Gravel Products gravel pitnear the edge of the Rio Grande gorge. This operation wasclosed in 2002 because it was determined to be too close tothe Rio Grande Wild and Scenic River Corridor and was situ-ated (in part) on un-permitted land. The site has since beenreclaimed.



may flow through a pit or quarry in an active flood-plain resulting in permanent changes in channel posi-tion that cause bank erosion and undercutting. Thiscan substantially alter the distribution of the energyand force of the stream. Levees or dikes protectpits/quarries from flooding and keep water and sedi-ment in the main channel. Engineered spillways allowcontrolled flooding and prevent deposition of sedi-ment in pits/quarries.

Few aggregate operations in New Mexico occurwithin active streams. Careful hydrologic studies andapplication of best management practices can allowaggregate to be extracted from active stream channelswith little environmental impact. The type and severi-ty of impacts are dependent on the geologic settingand characteristics of the stream. The main impactoccurs if more sediment is removed than the streamcan replenish. Sediment removal may be at one site orbe the total of many smaller operations. Sedimentremoval changes the stream cross section and increas-es gradient at the pit, which may cause widespreadupstream erosion and loss of riparian habitat. Adecrease in stream sediment by deposition in a pit cancause the stream to erode, resulting in similar effects.After aggregate extraction ceases, stream recovery canbe quite fast or take many years.

EROSION AND SEDIMENTATION

Quarrying can promote erosion, which can result inincreased sediment in nearby streams. Slope stability,water quality, erosion, and sedimentation commonlyare controlled by sound engineering and geologic

decisions. Appropriate slope angles are important.Roads, drainage ditches, and operational areas must fitthe particular site conditions. Disturbed areas can beprotected with vegetation, mulch, or other cover. Theycan be protected from storm water runoff by the useof dikes, diversions, and drainage ways. Sediment canbe retained on site using retention ponds and sedi-ment traps. Regular inspections and maintenance helpensure continued erosion control.

LAND SURFACE

Aggregate operations should avoid areas of knownlandslides and areas favorable for mass movement.Aggregate operations on an existing landslide or nearthe toe or head of a landslide can remobilize the slide.In areas where natural factors are not conducive toslope failure, aggregate extraction can cause landslidesif the pit or quarry is poorly located.

If a landslide does occur, it is likely to be near (butnot necessarily at) the quarry. Landslides are likely tooccur after quarrying starts, usually triggered by pre-cipitation. This could be a single event or a series oflandslides over an extended period of time. Geologicengineering techniques can identify existing landslidesand landslide-prone areas, but they cannot predictprecisely where or when a landslide will occur.

POST-QUARRYING IMPACTS

Most aggregate permits issued today in the UnitedStates require a formal reclamation plan and someform of guarantee (i.e., financial assurance) that recla-mation will be done. Forward-looking quarry opera-tors plan well in advance for the post-quarrying use ofthe site. Closed pits or quarries can be reclaimed asnatural habitat, especially if they intersect groundwater. Other uses include golf courses and otherrecreation, residential or commercial development,and parks. In many cases, post-closure uses equal orexceed the value of the pre-quarry use.

Wisely restoring the environment after aggregateproduction requires a design plan that responds to asite's physiography, ecology, function, artistic form,and public perception. Operating and reclaimedpits/quarries are no longer isolated from their sur-roundings. Analysis of a pit/quarry must go beyondthe site-specific and relate to its context in the region-al environment so a sustainable approach is useful.Understanding this aesthetic turns an industrial sitetypically perceived by the public as being undesirableinto a positive feature for the entire region.

Aggregate extraction site on the north end of Velarde that creat-ed an unstable highwall. Such sites can create problems fornearby communities including dust, truck traffic, infrastructuredamage, noise, and safety hazards. The back side of this high-wall is currently being mined, which will eliminate the steepslope and allow revegetation so the site will more closely resem-ble the surrounding terrain.

Documents

ENVIRONMENTAL AND WATER QUALITY ISSUES · 2009. 5. 8. · highly controversial when they conflict with other land uses or preservation. Near Sandpoint, Idaho, a mining company wants