Breccia-Pipe Uranium Mining in Northern Arizona— Estimate of Resources and Assessment of Historical Effects bout 1 million acres of Federal Aland in the Grand Canyon region of Arizona were temporarily withdrawn from new mining claims in July 2009 by the Secretary of the Interior because of concern that increased uranium min- ing could have negative impacts on the land, water, people, and wildlife. During a 2-year interval, a Federal team led by the Bureau of Land Management is evaluating the effects of withdrawing these lands for extended periods. As part of this team, the U.S. Geological Survey (USGS) conducted a series of short-term studies to examine the historical effects of breccia-pipe uranium mining in the region. The USGS studies provide esti- mates of uranium resources affected by Figure 1. The Kanab North Mine is one of several breccia-pipe uranium mines in northern Arizona. the possible land withdrawal, examine USGS scientists conducted field assessments at this mine, where operations are currently on the effects of previous breccia-pipe standby (USGS photo by Don Bills). mining, summarize water-chemistry data for streams and springs, and investigate findings will be used in an environmental exposed to the atmosphere, either naturally potential biological pathways of expo- assessment process to examine the poten- through erosion or by mining, these miner- sure to uranium and associated contami- tial effects of future mining activities. This als may be dissolved or broken down and nants. This fact sheet summarizes results fact sheet summarizes USGS research dispersed by wind and water. completed through December 2009 and Uranium mining in the Grand Can- through December 2009 and outlines presented in USGS Scientific Investiga- yon region peaked in the 1980s. However, further research needs. tions Report 2010-5025 (Alpine, 2010; there is now renewed interest in the explo- http://pubs.usgs.gov/sir/2010/5025/). ration and mining of breccia pipes in the Introduction region—uranium prices have increased, Background and concerns about clean energy and Citing concerns that uranium min- energy independence also have focused ing could have adverse effects on the Some of the highest grade uranium attention on uranium and nuclear energy. Grand Canyon watershed, its people, and ore in the United States occurs in breccia Currently, there are 104 U.S. nuclear wildlife, on July 21, 2009, Secretary of pipes scattered across the Grand Canyon reactors, which annually consume about the Interior Ken Salazar withdrew about 1 region (fig.1). These breccia pipes, named 27,500 tons of uranium oxide, the primary million acres of Federal land near Grand for their vertical, pipe-like shape and the constituent of the fuel rods that power Canyon from new mining claims for 2 broken rock, or breccia, that fills them, them. Each year, about 1,750 to 2,250 years. Mining of uranium can release range from 300 to 500 ft in diameter at tons of uranium oxide are mined domesti- toxic and hazardous substances to the depth. They were formed millions of years cally. The remainder of the uranium oxide environment. These include uranium ago when groundwater dissolved carbon- needed to fuel U.S. reactors comes from itself, which is a toxic chemical and can ate rock and created vertical cavities into foreign sources, primarily Canada, and the pose a radiation hazard, and arsenic and which surrounding rock collapsed. Later, U.S. utility inventory. other toxic trace metals. At the Secre- highly mineralized groundwater from Increased mining in northern Ari- tary’s request, the U.S. Geological Survey overlying or underlying rocks, mov- zona could help meet the U.S. demand for (USGS) conducted a series of short-term ing vertically through the porous brec- uranium but could also increase the amount studies to examine the effect of breccia- cia, deposited ore minerals—including of uranium and other trace elements in pipe uranium mining in the region. USGS uranium—in some of the pipes. When the local surface water and groundwater U.S. Department of the Interior USGS Fact Sheet 2010–3050 U.S. Geological Survey January 2011 flowing into Grand Canyon National Park land near Grand Canyon from new mining withdrawal and those previously withdrawn and the Colorado River. Deep mining claims for 2 years. The land proposed for from mineral mining, (2) an examination of activities could allow uranium and other withdrawal comprises three parcels (fig.2) surface contamination resulting from histor- trace elements to be mobilized by water —two parcels managed primarily by the ical (1980s) mining, (3) analyses of surface and transported into perched water-bearing Bureau of Land Management (BLM) to water and groundwater to determine if zones and the regional aquifer, which are the north of Grand Canyon (North and previous mining has affected water quality, sources of water for local communities and East Segregation Areas) and one parcel (4) compilation of the available informa- feed springs used by recreationists, fish, managed by the Forest Service on the tion on exposure pathways and biological and other wildlife. Additionally, waste rock, Kaibab National Forest south of Grand effects of uranium and associated con- ore, and dust from mined areas, if not prop- Canyon (South Segregation Area). taminants for plants and animals, and (5) a erly managed, could be transported away At the Secretary’s request, the USGS geological map of the House Rock Valley from the mines by wind and flood events. began a series of short-term studies to pro- area (East Segregation Area), Coconino The Secretary of the Interior cited vide (1) estimates of the uranium resource County, Arizona, with detailed stratigraphic such concerns when he withdrew Federal located on Federal lands proposed for and structural information (published 114°00' 113°30' 113°00' 112°30' 112°00' 111°30' Washington GRAND STAIRCASE ESCALANTE St. George NATIONAL MONUMENT Big Water UTAH Kanab 37°00' Colorado City KAIBAB - Virgin River ARIZONA Fredonia PAIUTE Lees Ferry Littlefield RESERVATION VERMILLION CLIFFS PIPE SPRING NM NATIONAL MONUMENT Marble Canyon NORTH Jacob Kanab Creek Lake SEGREGATION EAST AREA SEGREGATION KAIBAB NATIONAL FOREST AREA Hack Canyon 36°30' NAVAJO GRAND CANYON NATIONAL PARK RESERVATION GRAND CANYON - PARASHANT NATIONAL MONUMENT Havasu Creek LAKE Colorado River MEAD LAKE MEAD North Rim NRA NRA Supai Village HAVASUPAI L Creek i RESERVATION Bright Angel t tl e C o l o r 36°00' a Tusayan d o R HUALAPAI iver SOUTH RESERVATION r SEGREGATION e v i R AREA o C d olo ra Cataract Creek Valle Peach Springs 35°30' Data provided by U.S. Geological Survey and 0 25 50 MILES Bureau of Land Management. Map created on 11/10/09 by K.M. Brown Map revised on 5/24/10 by T. Arundel 0 25 50 KILOMETERS NEVADA UTAH EXPLANATION COLORADO U.S. Bureau of Land Management National Park Service Flagstaff U.S. Forest Service State land CALIFORNIA ARIZONA NEW MEXICO Tribal land Private land Phoenix Segregation area—Boundary Index map National Monument—Boundary Figure 2. Map of northwestern Arizona showing land ownership and the lands proposed for withdrawal from mining (the three Segregation Areas). separately). Results of those studies are Federal lands proposed for presented in Alpine (2010), and items 1 to 4 withdrawal on July 21, 2009 are summarized in this fact sheet. 12% Uranium Resource Availability Federal lands withdrawn before 2009 In 1990, the USGS estimated that 36% (Grand Canyon National Park, national northern Arizona breccia pipes contained 53% monuments, a game preserve, and Tribal lands) a mean undiscovered uranium endow- Federal, State, and private lands available ment of 1.3 million tons of uranium oxide for mineral development (Finch and others, 1990). This estimate, which is an average of high (2.8 million Figure 3. Pie diagram showing percentages of the total estimated mean uranium deposit in tons) and low (339,000 tons) probability northern Arizona for lands proposed for withdrawal from new mining on July 21, 2009, for lands estimates, is about three times the total withdrawn from mining before July 21, 2009, and for lands available for new mineral development. current uranium reserves in the rest of the United States (445,000 tons uranium oxide), as estimated in December 2003 and around several reclaimed or inactive contamination was greatest adjacent by the U.S. Energy Information Adminis- breccia-pipe uranium mines on BLM to a mine on standby status, where ore tration. In northern Arizona, the com- lands in the Kanab Creek area north of and waste rock have been at the surface bined uranium production for mines in Grand Canyon National Park. Surface for about 20 years. (4) Experimental the North and South Segregation Areas soil, sediment, and mined waste-rock data indicated that uranium solubility through 1994 was 11,650 tons. samples were collected at six differ- increases with increased weathering and In 2009, the USGS examined how ent sites that represent various stages of that leached trace-element concentrations much of the northern Arizona uranium mining—mined and reclaimed, partially derived from waste rock or ore can be endowment was made unavailable for mined and on standby, and mineralized very high. However, the dilution factors exploration, development, or mining by and explored by drilling but not mined— during flood events are also very high. previous withdrawals of Federal land and at an undisturbed area. (5) Finally, there was evidence of and by the proposed withdrawal (Alpine, Samples taken at breccia-pipe mine elevated but highly variable radioactivity 2010, chapter A). Areas excluded from sites were analyzed to determine histori- at all mine sites. mining before July 2009—including cal dispersion of uranium and other trace the national park, two national monu- elements by wind and water.