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T h e R e s o u r c e f o r S e m i - A r i d H y d r o l o g y

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Volume 7/Number 6 November/December 2008

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Whether you endorse or oppose mining uranium for nuclear energy, rising uranium prices and worldwide demand indicate the practice is on the upswing, and most U.S. deposits occur in the Southwest. Newspaper headlines in recent months describe numerous new mining claims, including in areas that encroach upon urban and national parklands, as well as ongoing threats to water quality from mining and milling operations that occurred decades ago. Uranium production likely is coming soon to an area near you.

Uranium production from the 1950s to the 1970s left a legacy of contaminated groundwater, surface water, and soils. The effects of tasteless, odorless radiation were not understood until after miners and users of the contaminated materials became seriously ill; only then were regulations for managing uranium production enacted. Now that uranium standards have been established, will the next uranium boom be any safer for humans and the environment? That remains to be seen. Some parties say yes, absolutely; others say no way. Finding a viewpoint that objectively weighs the advances in mining technology and protection of health and the environment against the inherent dangers of the handling of uranium proved impossible. But through this issue, we can become informed about what is involved, what has happened, and what might be different in the future.

We are pleased by the long list of contributors to this issue, making it truly a publication by and for the water professionals of the Southwest. Thanks to all of them, our eight 2008 sponsors (see page 9), and our 35 advertisers for providing the support that makes this issue possible.

Betsy Woodhouse, Publisher

A bimonthly trade magazine for hydrologists, water managers, and other professionals working with water issues.

Southwest HydrologyPublisher

Betsy Woodhouse

Technical EditorHoward Grahn

EditorMary Black

Graphic DesignersCindy GroomsShiloe Fontes

Technical WriterAlison Williams

SAHRA Knowledge TransferGary Woodard

Contributors

Advisory BoardDavid Bolin, R.G.Charles Graf, R.G.Jim Holway, Ph.D.

Jeff JohnsonDavid Jordan, P.E.

Karl Kohlhoff, P.E., B.C.E.E.Stan Leake

Ari Michelsen, Ph.DMark Murphy, Ph.D.

Peggy RoeferMartin Steinpress, R.G., C.HG.

Printed in the USA by CityPress

Southwest Hydrology is published six times per year by the NSF Center for Sustainability of semi-Arid Hydrology and

Riparian Areas (SAHRA), College of Engineering, The University of Arizona. Copyright 2008 by the Arizona Board of Regents. All rights reserved. Limited copies may be made for internal use only. Credit must be given to the publisher. Otherwise, no part of this publication may be reproduced without prior

written permission of the publisher.ISSN 1552-8383

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CONTACT USSouthwest Hydrology, The University of Arizona, SAHRA

PO Box 210158-B, Tucson, AZ 85721-0158. Phone 520-626-1805. Email [email protected].

Cynthia ArditoChristopher Brooks

Richard P. BushMike Crimmins

Laura E. CumminsDaniel W. ErskinePeter G. Griffiths

John MaddenChristopher S. MagirlVirginia T. McLemore

Judith D. MillerPhillip A. Pearthree

Mark S. PelizzaDavid M. Peterson

Jerry SchoeppnerJim Washburne

Shao-Chih (Ted) WayRobert H. Webb

Martha P.L. WhitakerClyde L. Yancey

Ann Youberg

From thePublisher

T h e R e s o u r c e f o r S e m i - A r i d H y d r o l o g y

After uranium is leached from ore, it is dried and filtered to produce yellowcake, an intermediate step in uranium ore processing, comprised of about 80 percent uranium. The photo shows yellowcake on a belt filter at a processing plant in France in 1995. Photo copyright AREVA Inc.

CorrectionCosts of the California State Water Project and Central Valley Project were incorrectly reported on page 22 of the Sept/Oct 2008 issue of Southwest Hydrology. The correct figures are $4.6 billion and $3.4 billion, respectively.

4 • November/December 2008 • Southwest Hydrology

Publishing Southwest Hydrology furthers SAHRA’s mission of promoting sustainable management of water resources in semi-arid regions.

This publication is supported by SAHRA (Sustainability of semi-Arid Hydrology and Riparian Areas) under the STC Program of the National Science Foundation, Agreement No. EAR-9876800. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of SAHRA or of the National Science Foundation.

Inside This Issue

18 Western Uranium Development: The Next Boom?Clyde L. Yancey and Betsy WoodhouseU.S. uranium production peaked in the 1970s, but record prices and growing demand in recent years has revived interest in uranium mining. What will be different this time around?

20 Uranium Geology of the WestClyde L. Yancey and Virginia T. McLemoreWhere in the West are uranium deposits found, and how did they form? Groundwater fl ow and geochemistry play key roles in the deposition of most types of ore bodies, as this hydrogeology primer describes.

22 Groundwater Remediation from Uranium Mining in New Mexico Jerry SchoeppnerExtensive uranium mining and milling in the Grants district of New Mexico predated modern environmental and health regulations. Groundwater remediation efforts have been complicated by many factors, including shifting uranium standards.

24 Finding Benchmarks at UraniumMine SitesDaniel W. Erskine and Cynthia ArditoAmbrosia Lake Valley of New Mexico provides a case study of the challenges of remediating uranium mine sites. These include shifting groundwater fl owpaths, water chemistry changes that accompany rewatering of the mine workings, and a lack of premining water quality benchmarks.

26 DOE Remediation of Uranium Mills:A Progress ReportDavid M. Peterson, Laura E. Cummins, Judith D. Miller, and Richard P. BushMost U.S. uranium production occurred before water quality standards for uranium existed. Once the hazards of uranium were understood, DOE became responsible for managing and monitoring surface and groundwater remediation efforts at all decommissioned uranium processing sites.

28 In-Situ Recovery of UraniumMark S. PelizzaIn-situ recovery reverses the process of uranium deposit formation, fi rst dissolving uranium from its ore body through a leaching process, then using ion exchange to remove the uranium from the leaching solution. Strict monitoring of the solution helps ensure its confi nement to the ore zone.

30 Well-Field Mechanics for In-Situ Uranium MiningShao-Chih (Ted) WayIn-situ recovery of uranium deposits involves an underground fl ushing process that causes less environmental disturbance than conventional mining methods. Understanding the hydrogeology of a uranium formation is essential to determine the method’s economic feasibility for a given deposit.

Departments8 On the Ground

Impacts of a 1,000-year rain event, by Robert H. Webb, Christopher S. Magirl, Peter G. Griffi ths, Ann Youberg, and Philip A. PearthreeProperty rights and groundwater use, by Christopher Brooks

12 GovernmentNM domestic well permits debatedCA struggles to manage droughtCO considers rainwater harvestingEPA proposes CO2 storage ruleNavigable rivers ruling muddies watersAn end to pilfering CO River waterGrand Canyon mining on hold?NV and UT face off over transfersEPA won’t regulate 11 contaminantsWater accord reached in SoCalHopi WQ standards approved

32 Climate Tools for Water ManagersTracking U.S. precipitation, by Mike Crimmins

36 R&DPlutonium migration explainedCanal bypass urged for DeltaDelta to become carbon-capture farmLowered streamfl ows can mean watershed healthDamming favors non-native fi sh

37 Business Directory and job announcement

38 EducationTeens research AZ rivers, by Martha P.L. Whitaker, Jim Washburne, and John Madden

39 In Print & OnlineManaging under climate changeTrees signal VOC presenceWater Resources 101Water sector at risk for corruptionDVD promotes water reuseWatershed planning handbookReal-time WQ info from USGS

42 Calendar

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Mining UraniumGroundwater was involved in the formation of many large uranium ore deposits, and increasingly groundwater (fortifi ed with other compounds) is being used to mine them using in-situ leaching methods. Uranium mining in the 20th century left a legacy of surface water and groundwater contamination that is still being dealt with today. Water quality standards for uranium were not enacted until after mining began, which means insuffi cient or no background data were collected to serve as baseline remediation goals. Love it or hate it (there doesn’t appear to be a middle ground), uranium mining is on the increase in the Southwest.


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ON THE GROUNDSlopes Fail, Debris Flowsin Extremis

Robert H. Webb, Christopher S. Magirl, and Peter G. Griffiths – U.S. Geological Survey and Ann Youberg and Philip A. Pearthree – Arizona Geological Survey

In the summer of 2006, an unusual set of atmospheric conditions aligned to produce record floods and an unprecedented number of slope failures and debris flows in southeastern Arizona. An upper-level low-pressure system stalled over New Mexico and drew subtropical moisture into southern Arizona, spawning strong convective systems for five consecutive nights. Rainfall from July 27-30 provided sufficient antecedent moisture so that the big storms of July 31-Aug. 1 caused record stream flooding in northeastern Pima and eastern Pinal counties. New floods of record, with recurrence intervals (RIs) of about 100 to 500 years, were established at five gauging stations. In the southern Santa Catalina Mountains north of Tucson, the maximum three-day precipitation measured was 12.04 inches, which has an RI of about 1,000 years. Four-day rainfall totals in three other nearby mountain ranges also exceeded 1,000-year RIs.

Unprecedented Numbers

The watersheds affected in the event had experienced large floods several times in the 20th century, but the 2006 event was unique for the extraordinary number of slope failures and debris flows that occurred. At least 623 slope failures occurred in four mountain ranges, including 435 in the southern Santa Catalinas. Debris flows reached or passed the apexes of alluvial fans in five drainages on the northern edge of Tucson.

Anecdotal records accumulated by the Arizona Geological Survey reveal few previous episodes of slope failures and debris flows in this region, and none with this magnitude. Repeat photography suggests that the 2006 spate of slope failures was historically unprecedented, and geologic mapping and cosmogenic dating of ancient debris-flow deposits indicate that few debris flows have

reached alluvial fans in the Tucson basin in the past few thousand years. Although recent watershed changes may have been important locally, the record number of slope failures and debris flows were related predominantly to extreme precipitation and not other factors such as fire history. Large regions of the Santa Catalina Mountains had burned in 2003, but 86 percent of the 2006 slope failures in this range started in unburned or low-intensity burn sites. Of the other affected mountain ranges, one had no record of significant fire and another (Bowie Mountain) had not burned in 80 years.

Relating Precipitation to Slope Failure

The combination of relatively dense point rainfall data and nearby weather radar provided a unique opportunity to compare high-spatial-frequency estimations of storm return periods to slope failures. Radar returns were accumulated in 754 grid cells approximately 0.36 square miles in size over the south half of the Santa Catalinas. Precipitation intensities measured with weather radar on July 31 were not unusual in this region (RI less than one year), but multiday rainfall where slope failures occurred typically had RIs greater than 50 years; isolated grid cells had RIs of 500 to 1,000 years. Sabino Creek watershed

in the Santa Catalinas was essentially saturated following four days of rainfall: 92 percent of the precipitation ran off.

Using data from numerous sources, including digital orthophotography, Google Earth images, and airborne Lidar data, the volume of sediment moved from hillslopes by the slope failures in the southern Santa Catalina Mountains was estimated to be 23.7 million cubic feet. LAHARZ, a stochastic debris-flow simulation model typically used to predict the area of deposition of lahars (mudflows associated with volcanic eruptions), was used to simulate the depositional areas observed from the five debris flows that reached or passed the apexes of alluvial fans on the northern edge of Tucson. Using the estimated sediment volumes for slope failures in each watershed, LAHARZ successfully predicted the approximate areas of deposition for four of the five debris flows. The LAHARZ simulations both verified the volume estimates of material released by the 2006 storm as well as demonstrated the feasibility of using this stochastic modeling technique to predict debris-flow-hazard potential in steep mountain watersheds of the arid Southwest.

Contact Robert Webb at [email protected].

A debris flow filled this section of Sabino Creek and the adjacent roadway in the Santa Catalina Mountains of southern Arizona.

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November/December 2008 • Southwest Hydrology • 9

ON THE GROUND (continued)

Comparing Groundwater Use Under Contrasting Property Regimes

Christopher Brooks – Water Strategy Consulting LLC

Does the type of property right that pertains to a natural resource affect its use? Economic theory predicts that where no property rights exist, users are more likely to undervalue future use, resulting in rapid depletion of the resource from wasteful and inefficient use. In contrast, where property rights do exist, users of the resource are predicted to be more likely to properly value future uses, resulting in a rate of consumption consistent with the most efficient use of the resource over its expected life.

Testing the Theory

Groundwater can be used to test this theory, because the legal regimes governing rights to groundwater vary from state to state, even where adjacent states share a common aquifer, as do Texas and New Mexico in the High Plains. In all

cases, rights to groundwater are limited to use rights associated with an amount that can be pumped to the surface. But at one extreme, groundwater users in Texas, under the rule of capture, have effectively no property rights in groundwater. In contrast, groundwater users across the border in New Mexico, under prior appropriation, have what has been regarded as the closest approximation to full property rights in groundwater.

Therefore, data on groundwater pumpage and agriculture were compared for three counties in New Mexico and nine counties in Texas that overlie the Ogallala (or High Plains) aquifer, with a similar overall land area in each state. The counties were chosen for their physical similarities and farming practices, as well as their adjacent locations along the state border (see map). The data were compiled from readily available sources, including the U.S. Geological Survey, Department of Agriculture, Census Bureau, and state well-registry databases, and included county-level population

data, groundwater pumpage for irrigation by county averaged over 1985 to 2000, the amount of land in agriculture and amount of land in irrigated agriculture by county averaged over 1987 to 2002, and the number of irrigation wells by county.

The entire study area has a semi-arid climate and is dominated by center-pivot irrigation of wheat, corn, sorghum, and cotton. However, previous studies indicate there is significantly more water stored in the Ogallala under Texas than under New Mexico.

The data showed that nearly six times as much land is irrigated farmland and over three times as much water is used for irrigation in the Texas counties compared to the New Mexico counties. This clearly supports the prediction that more groundwater use and irrigated farming will occur under rule of capture (Texas) than under prior appropriation (New Mexico), all other things being equal. Also, the table (below left) shows that groundwater use per capita, per acre, and per well were all significantly higher in Texas.

Prior Appropriation Drawback

One surprising result was that groundwater use for irrigation appears

County

Irrigation wells per

capita

Irrigation wells

per acre irrigated

Annual irrigation groundwater use

per capita (acre-feet/

person)

per acre of land (acre-feet/acre)

per well (acre-

feet/well)

per irrigated acre (acre-feet/acre)

New Mexico counties (total area = 5.3 million acres, annual irrigation groundwater use = 536,000 acre-feet)

Curry 0.03 0.0156 5.37 0.27 173.52 2.70

Lea 0.03 0.0400 2.03 0.04 69.42 2.77

Roosevelt 0.10 0.0224 10.06 0.12 105.54 2.36

Average 0.05 0.0260 5.82 0.14 116.16 2.61

Texas counties (total area = 5.4 million acres, annual irrigation groundwater use = 1.79 million acre-feet)

Deaf Smith 0.04 0.0047 11.37 0.22 288.00 1.35

Parmer 0.02 0.0013 32.28 0.57 1303.87 1.63

Castro 0.02 0.0009 44.17 0.64 1946.62 1.77

Bailey 0.03 0.0032 25.40 0.32 782.62 2.49

Lamb 0.02 0.0015 20.94 0.47 959.56 1.45

Cochran 0.03 0.0019 16.26 0.12 546.46 1.03

Hockley 0.01 0.0013 4.94 0.19 732.96 0.97

Yoakum 0.01 0.0008 13.60 0.19 1747.02 1.35

Terry 0.01 0.0009 11.19 0.25 1385.83 1.22

Average 0.02 0.00182 20.02 0.33 1076.99 1.47

Curry

Deaf Smith

Parmer Castro

Roosevelt Bailey Lamb

Lea Yokum Terry

Cochran Hockley

NewMexico

Texas

OK

TXNM

Analysis of data on wells, irrigated land, and groundwater use in the study area.Location of counties in study area. Image obtained from www.nationalatlas.gov.


to be more efficient in Texas, where significantly less groundwater is used per irrigated acre. This indicates a potential drawback to quantified groundwater rights under prior appropriation: there is little incentive to increase irrigation efficiency if the user would thereby forfeit a portion of the right and be unable to receive the benefits of higher efficiency. Under the rule of capture, the right is not based on a specified quantity of water, so users who improve efficiency can benefit from their efforts. This observation, that efficiency gains often do not lead to net savings of groundwater, has been noted by others.

The analysis showed that while having well-defined rights to groundwater may reduce overall groundwater use, it may come at the cost of perpetuating inefficient uses of the resource and discouraging future efficiency gains.

Contact Christopher Brooks at [email protected].

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GOVERNMENTDenial of Domestic Well Permits Debated in NM

The process for obtaining a domestic well permit in New Mexico may become longer and more complicated, reported the Albuquerque Journal in July. The state’s practice of approving all domestic well applications, typical throughout the West, was ruled a violation of the state doctrine of prior appropriation by a New Mexico district court.

An existing state statute appears to give the New Mexico Office of the State Engineer no opportunity to deny a domestic well permit. A southern New Mexico farmer filed suit against the state in 2006, claiming that domestic wells in his area were drying the Upper Mimbres River and impairing his senior water rights. Although the district court judge found no evidence of impairment, he ruled the domestic well statute unconstitutional, saying it does not allow due process for senior water rights holders, according to the Journal. He noted in his decision that irrigators cannot “sit idly and wait for actual impairment. When the water is gone, it will be too late.”

The judge concluded that the state engineer must treat applications for domestic wells the same as any other water right―a process requiring public notice, review by staff for potential impairment to existing rights, and the opportunity to protest. If a permit is not approved, water rights can be purchased in the open market, where they sell for as much as $15,000 per acre-foot, reported the New Mexico Independent.

State Engineer John D’Antonio previously warned the legislature that such a ruling might happen if the statute was not amended, reported the Journal. He has filed a friendly appeal in the case to “ensure that every legal basis in support of the presumption [of constitutionality of the statute] is fully deliberated,” according to an agency press release. The decision will not be enforced during the appeal.

D’Antonio told the Journal that his office processes 7,000 to 8,000 domestic well applications each year, and the extra work of reviewing them “could bog down” his agency and delay the permitting process.

Until 2006, domestic wells were permitted to withdraw three acre-feet per year; that number has been reduced to one acre-foot. The vast majority of domestic wells in the state are not metered.

Visit www.ose.state.nm.us, www.abqjournal.com, and www.newmexicoindependent.com.

CA Drought Prompts Actions

In response to California Gov. Arnold Schwarzenegger’s statewide drought proclamation on June 4 and state of emergency proclamation on June 12 for nine counties affected by severe water shortages, the California Department of Water Resources (DWR) announced in July that it was entering into water transfer agreements to aid Central Valley farms.

Some 50,000 acre-feet of water was to be pumped into the State Water Project (SWP) from groundwater wells in the Westlands Water District, then transferred to other parts of the district lacking groundwater access. DWR also planned to lend 37,500 acre-feet of water to Central Valley Project (CVP) contractors from the San Luis Reservoir.

Metropolitan Water District of Southern California made available 25,000 acre-feet of water to benefit both CVP and SWP contractors by delaying their own delivery until later in the year, after the growing season, reported the Fresno Bee.

In addition, DWR began expediting $12 million in grants to water agencies and nonprofit organizations for water conservation activities. The agency also awarded $6.4 million in grants to 31 public agencies from the Local Groundwater Assistance Program. These funds supported activities such as development of groundwater management plans and programs, installation of

groundwater monitoring wells, hydrogeologic studies of groundwater basins, and development of groundwater models and data storage systems.

Visit www.dwr.water.ca.gov and www.fresnobee.com.

Colorado Closer to Harvesting Rain

Colorado Gov. Bill Ritter signed a bill in May allowing the first use of rainwater harvesting in the state. The bill charges the Colorado Water Conservation Board and the state engineer with selecting up to ten new residential developments to conduct cistern pilot projects and authorizes the collection of 5,000 gallons of rainwater per single-family home in those projects. The water must be used for fire protection, watering of animals on farms and ranches, or irrigating gardens and lawns up to one acre.

Colorado currently does not allow rainwater harvesting because state water law requires all rainwater be allowed to flow downstream to water rights holders, reported the Denver Post in April.

The Water Resources Review Committee must study issues related to the exemption created by the bill, which lasts for three years. The study will address whether the practice prevents a significant amount of water from reaching rivers, or whether most of the rainwater would have infiltrated into the ground anyway, added the Post. Only new developments can participate so that the study can address groundwater infiltration before and after development.

Visit www.colorado.gov, www.leg.state.co.us, and www.denverpost.com.

EPA Proposes Carbon Dioxide Storage Rules

In July, the U.S. Environmental Protection Agency proposed a rule for the underground injection of carbon dioxide for long-term storage, also known as


geologic sequestration. The regulation was proposed under the Safe Drinking Water Act to make sure that injection-related activities do not have deleterious effects on underground sources of drinking water.

Geologic sequestration of carbon dioxide can reduce carbon emissions to the atmosphere and may help mitigate climate change. Because carbon dioxide has a unique combination of properties including relative buoyancy, corrosivity in the presence of water, high likelihood of the presence of impurities, and mobility in the subsurface, and because of the large injection volumes anticipated, EPA needed to create a new injection-well classification and modify technical criteria under its existing Underground Injection Control program.

The rule establishes criteria for “geologic site characterization; area of review and corrective action; well construction and operation; mechanical integrity testing and monitoring; well plugging; post-injection site care; and site closure for the purposes of protecting drinking water,” according to an EPA fact sheet. It would apply to owners and operators of wells that will be used to inject carbon dioxide into the subsurface for the purpose of long-term storage.

EPA is coordinating with the Department of Energy on carbon sequestration research and development.

Visit www.epa.gov/safewater/uic/wells_sequestration.html.

Rapanos Decison Is Affecting CWA Enforcement

A U.S. Supreme Court decision related to the Clean Water Act and a subsequent guidance document by federal agencies have adversely impacted enforcement of clean water programs, reported two House Committee chairmen in July.

Chairman James L. Oberstar of the Committee on Transportation and Infrastructure and Chairman Henry A.

Waxman of the Committee on Oversight and Government Reform obtained an internal U.S. EPA memo from Granta Y. Nakayama, EPA’s assistant administrator for enforcement and compliance assurance, to Benjamin Grumbles, the agency’s assistant administrator for water.

In the memo, Nakayama cited approximately 500 enforcement cases that were negatively affected in a nine-month period as a result of the three separate opinions in the 2006 Rapanos v. United States case and the 2007 guidance produced by EPA and the Army Corps of Engineers to address that decision. Rapanos dealt with the definition of navigable waters, which are protected under the Clean Water Act, yet did not clearly define them.

The chairmen sent a letter to EPA Administrator Stephen L. Johnson to request more information about the agency’s enforcement protocols. They

also pointed out that in three hearings held by the Committee on Transportation and Infrastructure related to the Rapanos decision, the Bush Administration failed to reveal the extent to which the uncertainty created by the decision was undermining the protection of clean water.

Copies of relevant communications were to be submitted to the committees by July 21. Both committees have oversight jurisdiction over EPA and enforcement of the Clean Water Act, and both planned further oversight on this issue.

Visit oversight.house.gov/documents/20080707150814.pdf.

Colorado River Pilferers May Be Cut Off

Well owners near the Colorado River in Arizona, California, and Nevada who pump river water without proper

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GOVERNMENT (continued)

entitlement may soon be cut off. The Bureau of Reclamation has proposed such a rule in order to properly account for the use of lower Colorado River water and to ensure existing and future use of the water consistent with federal law.

Reclamation says the rule will help ensure the long-term sustainability of the lower Colorado River, which over the past eight years has been affected by severe drought conditions. It will also protect the water rights of lower Colorado River water entitlement holders.

The 1928 Boulder Canyon Project Act requires all Colorado River water users in the lower basin to have an entitlement to that water, but current data indicate that 9,000 to 15,000 acre-feet of Colorado River water is used in the lower basin each year without entitlement. Most of this use is from wells located in the river’s floodplain that are hydraulically connected to the river. The Arizona Republic reported that more than half the wells affected are in Arizona.

The proposed rule will adopt a methodology to determine which wells are pumping Colorado River water, establish criteria for water users to demonstrate that their wells do not pump

water that would be replaced by river water, establish an appeals process, provide for public review and comment, and importantly, provide options for unlawful users to legitimize their use.

Well owners may be able to acquire water still available under the states’ apportionments. The Republic cited as much as 10,000 acre-feet of unallocated water in Arizona, but virtually nothing available in California and Nevada. Other options include transferring or leasing from an existing assignment, becoming a customer of an existing entitlement holder, and acquiring a different source of water.

Visit www.usbr.gov/lc/region/programs/unlawfuluse.html and www.azcentral.com

Transfers Excluded from NPDES

In June, the U.S. EPA published a final rule clarifying that water transfers are not regulated under the Clean Water Act’s (CWA) National Pollutant Discharge Elimination System (NPDES) permitting program.

The basis for EPA’s rule is a legal interpretation of the CWA indicating that Congress intended for states to have primary oversight of water transfers in cooperation with federal authorities, rather

than subjecting transfers to the NPDES program. In addition, pollutants are not added to water during the transfer process, as any pollutants present are alreadyin the water.

The rule excludes from the definition of water transfer those that are subjected to “intervening industrial, municipal, or commercial use” and does not apply to “pollutants introduced by the water transfer activity itself to the water being transferred.”

Visit www.epa.gov/npdes/agriculture.

Western Mining Claims Hot, But Not in Grand Canyon?

Mining claims have exploded throughout the West in the last five years, due to high prices for copper, gold, and uranium. Total claims within five miles of western cities and towns increased 46 percent—from 35,350 to 51,000—between 2003 and 2008, according to an analysis of Bureau of Land Management records by the Environmental Working Group. The Las Vegas and Phoenix metropolitan areas are each closely surrounded by over 5,000 claims.

The U.S. EPA has named metal mining the country’s top toxic polluter for nine straight years and reported that mining has contaminated 40 percent of the headwaters of western watersheds. Uranium is a double threat to water quality because it is both a toxic heavy metal and radioactive.

Last spring, the U.S. Forest Service approved applications to start exploratory drilling for uranium on the Kaibab National Forest near the South Rim of the Grand Canyon. But after environmental groups sued, the Forest Service agreed in September to withdraw the application approval and to require a full Environmental Impact Statement (instead of using a categorical exclusion) before allowing any renewed attempts to drill.

continued on page 16


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GOVERNMENT (continued)Meanwhile in June, the U.S. House Natural Resources Committee adopted a resolution requiring that the Secretary of the Interior immediately withdraw more than one million acres of federal land adjacent to Grand Canyon Park from future mining claims for up to three years.

The Arizona Daily Star reported in June that Committee Chair Raul Grijalva expected the Secretary to either not enforce the ban or to challenge it in court. “This will be good for three to six months,” Grijalva told the Star. “Even if it’s challenged and we lose, I think the focus on the Grand Canyon is good.”

Visit www.ewg.org, www.azstarnet.com, and resourcescommittee.house.gov.

NV, UT Oppose Each Other’s Proposed Water Transfer

What do Utah and Nevada have in common when it comes to water resources these days? Both have plans to build 100-plus-mile pipelines to transport water to fast-growing areas of the states and both oppose each other’s plans because of environmental and growth issues.

In June, the Salt Lake Tribune reported on Southern Nevada Water Authority (SNWA) General Manager Patricia Mulroy’s opposition to the selection

of the Federal Energy Regulatory Commission (FERC) as the federal lead in managing environmental studies of Utah’s proposed pipeline from Lake Powell to three fast-growing southern counties. Mulroy questioned FERC’s narrow expertise and lack of identification of “significant cumulative impacts” related to interbasin water transfers such as “induced growth and…impacts on lands and water resources in and surrounding the areas to be served.”

In July the Tribune reported that Utah officials object to SNWA’s proposal to pipe water from Snake Valley on the Utah-Nevada border to Las Vegas, fearing it would lower the water table, causing dust storms and degraded air quality. Local ranchers worry that their ability to grow is being exchanged for future growth in Las Vegas, said the Tribune, meanwhile Mulroy said it would be “unreasonable” to develop the Lake Powell pipeline partly because it is planned for people not yet living in southern Utah.

Mulroy wrote a reaction piece to the Las Vegas Sun’s series on her agency’s proposed project, saying that the opposition’s dire environmental predictions for rural areas from which Las Vegas plans to import water ignore both science and environmental safeguards in state and federal law. She added that

the pipeline is not just for future growth: if Lake Mead were to go dry as some predict, even the current population could not survive on the ten percent of its water supply that now comes from sources other than Lake Mead.

SNWA’s Snake Valley proposal is part of a larger importation plan. Last July, Nevada State Engineer Tracy Taylor granted SNWA 18,755 acre-feet per year (about half the water they applied for) from Cave, Dry Lake, and Delamar valleys. Rulings for Spring Valley have already been issued, and hearings on the Snake Valley application are scheduled to begin in fall 2009.

Visit www.sltrib.com, www.lasvegassun.com, and www.water.utah.gov.

EPA Won’t Regulate 11 Contaminants

The U.S. EPA will not regulate 11 contaminants on the second drinking water contaminant candidate list (CCL 2) because they do not occur nationally in public water systems or they occur at levels below a public health concern.

EPA is, however, updating health advisories for seven of the 11 contaminants in order to include current health information for situations


where the contaminants may be present. These include boron, 2,4-dinitrotoluene, and 2,6-dinitrotoluene (used in manufacturing); dacthal mono- and di-acid degradates (herbicides);1,3-dichloropropene (soil fumigant); and 1,1,2,2-tetrachloroethane (volatile organic).

EPA is not updating or creating health advisories for 1-dichloro-2,2-bis (p-chlorophenyl) ethylene (degradate of the pesticide DDT), s-ethyl propyl thiocarbamate and Terbacil (herbicides), and Fonofos (insecticide) because national monitoring data showed almost no occurrence at levels of public health concern as determined by peer-reviewed data.

Under the Safe Drinking Water Act, EPA is required to develop a CCL every five years and to make a regulatory determination for at least five contaminants on each list. CCL 1 was published in 1998 and CCL 2, made up of 51 contaminants from CCL 1, was published in 2005. In February 2008, EPA published CCL 3, with 104 contaminants.

In May 2007, EPA requested public comment on their preliminary decision not to regulate these 11 contaminants from CCL 2. The agency’s final regulatory determination is based on

extensive review of health effects, occurrence data, and public comments.

Visit www.epa.gov/safewater/ccl/ and yosemite.epa.gov/opa/admpress.nsf.

Tribe, Water Districts Resolve Conflict

Decades of litigation between the Soboba Band of Luiseño Indians and various water districts in Southern California ended with President Bush’s signing of a settlement act in July. The tribe filed a lawsuit in 2000 against Metropolitan Water District (MWD), claiming that a tunnel constructed by MWD in 1932 to transport water from the Colorado River to Southern California was illegally draining water from the Soboba reservation. The act approves a settlement agreement dated June 7, 2006 (see Southwest Hydrology, Sept/Oct 2006) involving the Soboba Band, MWD, and other area water districts.

The bill, introduced by Congresswoman Mary Bono Mack in December 2007, was broadly supported by Congress, local leaders, and residents, including the Soboba Band, the City of Hemet, the City of San Jacinto, MWD, the Lake Hemet Water District, and the Eastern Municipal Water District.

The act also creates new sources of water for San Jacinto Valley residents and assists both the tribe and local residents with critical water infrastructure needs.

Visit bono.house.gov/news.

EPA Approves Hopi Standards

In July, the U.S. EPA approved water quality standards for the Hopi tribe in northeastern Arizona. Now 33 tribes across the United States have water quality standards effective under the Clean Water Act.

EPA’s approval action culminates a two-step process that began with its April 2008 finding that the tribe was eligible to be treated in the same manner as a state for administering a water quality standards program. The second step—approval of the water quality standards—ensures that all surface waters within the boundaries of the Hopi Indian Reservation are covered by standards under Section 303(c) of the Clean Water Act, including designated uses and water quality criteria. The standards can now form the basis for federally enforceable regulatory requirements. EPA provides technical assistance to tribes to develop and implement water quality standards, and to manage other water quality programs.

Visit www.epa.gov.

• Supporting water resource decisions

• Analyzing regulatory and economic opportunities, risks, and trends

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Errol L. Montgomery & AssociatesWater Resource Consultants

www.elmontgomery.com Toll Free 866.744.6133Tucson • Phoenix • Santiago de Chile

• Supporting water resource decisions

• Analyzing regulatory and economic opportunities, risks, and trends


No other element on the periodic table elicits quite as strong a reaction as atomic number 92,

uranium. It is the heaviest of all naturally occurring elements and is ubiquitous in nature. Uranium has been mined in the United States since the latter 19th century. Early on, it was used to color glass and ceramic glazes, and to obtain radium, a common byproduct of uranium processing, which was needed in the field of medicine. Development of the atomic bomb by the United States during World War II and growing energy demands following the war led to greatly increased production and use of uranium. In the late 1950s and early 1960s, uranium was in demand for use in nuclear weapons (Shawe and others, 1991). Uranium production in the United States again peaked in the 1970s, due to the

increased development of nuclear power, then declined sharply after 1980 because of environmental concerns, health concerns for uranium miners, and the availability of cheaper foreign energy sources.

Currently we find ourselves in another uranium boom cycle driven by demand for nuclear power across Asia, Europe, and Africa, as well as North and South America. Uranium development is gathering momentum through the expansion of global distribution of reactor units (439 operating, 36 under construction, 93 in planning, and 218 proposed). The western United States used to be the world’s leader in production of uranium. Now 95 percent of our uranium is imported from Canada, Australia, Kazakhstan, Namibia, Uzbekistan, and Russia.

The U.S. BottleneckWestern U.S. uranium development is at a bottleneck that is continuing to tighten due to infrastructural impediments and conflicting opinions about its legacy versus current safety standards. But technology and the protection of both worker health and the environment in the U.S. uranium extraction industry have improved in the past decade. The United States will likely see an imminent increase in small-scale conventional (open-pit and underground) mining and processing in the Colorado Plateau, and the continued use of in-situ recovery (ISR, see pages 28 and 30) in the Rocky Mountain and Texas coastal plain regions. Both methods are now highly regulated and monitored by multiple state and federal agencies.

Current U.S. uranium production in the Colorado Plateau comes from conventional mining, but is limited by only one operating uranium mill in Utah. Additional mills are

How Bad Is It?

Uranium can be both chemically

and radioactively toxic. Chemically,

large amounts of uranium can cause

kidney damage in humans. Long-

term exposure to radiation from

uranium’s decay products, especially

radium and radon, can cause cancer

(uranium itself is not known to cause

cancer). Uranium and its decay

products enter humans and other

mammals primarily by inhalation

(such as radon gas or uranium dust

in building materials) and ingestion

(such as in drinking water).

Western UraniumWestern UraniumDevelopment: The Next Boom?Development: The Next Boom?

Clyde L. Yancey – Uranium Energy Corporation and Betsy Woodhouse – Southwest Hydrology

It’s a Southwest necessity.Together we can attain it.

• Groundwater resource evaluation and basin inventory analysis• Modeling of groundwater and surface water flow systems• Wellhead and aquifer source protection• Assured water supply planning and development• Litigation support for water rights and resource damage• Water quality evaluation and treatment (including arsenic)

For more information, contact Brad Cross at 480.905.9311 or via e-mail at [email protected].

LFR Inc. is an environmental management & consulting engineering firm with 29 offices nationwide. For more information, call 800.320.1028 or visit us at www.lfr.com.


planned, but permitting times are lengthy. ISR production currently occurs in Wyoming, Nebraska, and Texas; other mines are in the permitting stage in these states as well as Colorado and South Dakota.

Production in New Mexico, where tremendous uranium resources exist, is hampered by the lack of an operating mill and concerns related to groundwater protection, conflicting cultural beliefs, and perceived mine impacts. Even with expanded domestic uranium mining, the United States will continue to have a significant need to purchase uranium in the global market to fulfill current and projected energy requirements.

Then Versus NowWhy, as hydrologists and water managers, do we care about uranium mining? Because no matter how we may feel about nuclear energy or other uses of uranium, the worldwide demand for it is high and uranium mining is going to increase in the Southwest, presenting numerous hydrologic, water chemistry, and policy issues that are important to consider:• How have regulations for protecting groundwater and remediating

mined-out sites changed since the mining boom of the 1970s, when water quality standards for uranium were lacking? How do those differences impact water quality, the development of new mines, and the cleanup of old mines?

• What has happened to the old mining and milling operations that contaminated groundwater?

• How does in-situ mining and uranium recovery actually work from the standpoint of water chemistry, well mechanics, and aquifer properties? In-situ mining is becoming more prevalent because of the types of deposits that are being mined and because it does not generate the large amounts of tailings that conventional practices do. A saturated, confined aquifer with certain ranges of hydrologic properties is essential to making in-situ work, but how is containment of the uranium-bearing fluids ensured?

• How are background water quality levels determined? For old mines now being reclaimed, this is a particular challenge: background uranium data were not collected prior to the start of mining because uranium standards did not exist then. Mineralized areas generally have poor water quality before mining even begins, yet some argue that existing regulations may allow the “contaminated” zone to extend even further once the mines are developed.

These issues are addressed by the following articles, along with background about how uranium deposits are formed and extracted.

ReferenceShawe, D.R., J.T. Nash, and W.L. Chenoweth, 1991. Uranium and vanadium deposits,

in The Geology of North America, Vol. P-2, Economic Geology, U.S., Geologic Society of America, pp 103-123.

No matter how we may feel about nuclear energy or other uses of uranium, the worldwide demand for it is high and uranium mining is going to increase in the Southwest.

World production

• Total production: 45,500 tons uranium

• 60% of production (27,258 tons) was from three

countries:

Canada (23%)

Australia (21%)

Kazakhstan (16%)

• 4% was from the United States (1,800 tons)

Production method

• Conventional underground and open pit: 61%

• In-situ leach: 29%

• By-product: 10%

Top known recoverable sources of uranium (tons

uranium, percent of world reserves)

• Australia (1.3 million, 23%)

• Kazakhstan (901,000, 15%)

• Russia (602,000, 10%)

• South Africa (480,000, 8%)

• Canada (466,000, 8%)

• United States (377,000, 6%)

• The world’s known uranium resources increased 15%

from 2005 due to increased mineral exploration.

• Seven companies marketed 85% of the world’s

uranium mine production.

In the United States

• Six underground and five in-situ leach mines operated,

along with just one uranium mill (in White Mesa, Utah)

• 4,000 mines have a history of uranium production

• 104 nuclear reactors provided 19% of U.S. electricity

• Amount of uranium used for nuclear weapons: not

published

ReferencesOECD (Organisation for Economic Co-operation and Development), 2006. Forty

Years of Uranium Resources, Production and Demand in Perspective. OECD Publishing.

OECD and the Industrial Atomic Energy Agency, 2008. Uranium 2007: Resources, Production and Demand. http://213.253.134.43/oecd/pdfs/browseit/660831E.pdf.

U.S. Energy Information Administration (accessed August 2008): www.eia.doe.gov

2007 UraniumProduction Statistics

Western UraniumDevelopment: The Next Boom?

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

1945 1954 1964 1974 1984 1994 2004year

production(metrictons)

$0

$10

$20

$30

$40

$50

$60

$70

$80

$90

$100

price($/pound

U3O8)

worldwide U.S. price

Worldwide and U.S. Uranium Production Compared to Price(source: OECD 2006 and 2008)


Understanding how and where uranium deposits form provides the background for considering

water quality, hydrologic, and regulatory aspects of uranium mining.

Finch (1996) defined, described, and modeled the North American uranium provinces, including four that cover the western United States: Colorado Plateau Uranium Province (CPUP), Rocky Mountain and Intermontane Basins Uranium Province (RMIBUP), Gulf Coast Uranium Province (GCUP), and Basin and Range Uranium Province (BRUP) (see map right, and table below).

Where Did It Come From?Uranium occurs naturally within the rocks that form the earth’s crust,

particularly in granite, volcanic ash, and volcanic lavas with granite-like compositions. Some deposits occur as uranium-rich veins that formed from granitic magmas, but most formed when oxidizing groundwater leached uranium from igneous rocks and transported it to reducing environments where uranium precipitated and became concentrated.

The volcanic activity that provided uranium to the Colorado Plateau deposits was likely located to the west and south, at the edge of the North American tectonic plate. Uranium-rich volcanic ash and tuffs derived from what is now the Basin and Range area and the Rocky Mountains covered the intermontane basins of that area. Localized granitic sources also are found in the RMIBUP, as well as magmatic vein deposits

in the central Rockies of Colorado. Volcanism near Big Bend National Park, Texas, and Mexico provided uranium for the Texas Coastal Plain deposits.

How Do Deposits Form?Most uranium deposits in the western United States were formed by one of four mechanisms described below.

Roll-front deposits are aquifer-controlled ore bodies that form in medium- to coarse-grained sandstone. Oxidizing groundwater leaches uranium from its source rock and carries it through sandstone until it reaches a reducing environment, caused by the presence of buried organic material or gases such as hydrogen sulfide. Uranium precipitates at the interface between

Clyde L. Yancey – Uranium Energy Corporation and Virginia T. McLemore – New Mexico Bureau of Geology and Mineral Resources

Uranium province

% of total uranium in the 4

provinces

Amount already

produced

Types ofdeposits

Size (tons) and grade (U3O8)

Potential resource

(tons U3O8)

Associatedores

Mineralizingsolutions

Colorado Plateau (CPUP)

55 two-thirds tabular sandstone, solution-collapse breccia pipes

500-200,000 at 0.05 to 0.60%

6x105 vanadium and copper

groundwater

Rocky Mountain and Intermontane Basins (RMIBUP)

32 half roll-front and volcanic (hydrothermal veins)

roll-front: 500-20,000 at 0.04-0.23%; vein: 500-5,000 at 0.15-0.48%

3.5x105 vanadium groundwater (roll-front) and hydrothermal fl uids (veins)

Gulf Coast (GCUP) 9 three-fourths roll-front 500-10,000 at 0.04-0.39 %

1x105 molybdenum groundwater

Basin and Range (BRUP)

4 resources are increasing

volcanic (hydrothermal vein and tabular sandstone composite)

500-20,000 at 0.05 to 0.10%

4x104 molybdenum, vanadium, fl uorite, and mercury

hydrothermal fl uids, meteoric waters; and geothermal groundwater

Characteristics of the uranium provinces of the western United States (after Finch, 1996).

Uranium

Geology

of the West

Autunite (hydrated calcium uranyl phosphate), is a fluorescent, radioactive uranium ore mineral.


oxidizing and reducing conditions, often forming a curved “roll-front” ore body. This reduction/oxidation front can migrate over time, creating an ore trend that extends for miles. Numerous ore bodies are sometimes stacked parallel to one another at intervals along this trend, reflecting preferential flowpaths in the aquifer.

Roll-fronts are the predominant uranium deposit in the RMIBUP and the CPUP, and the only type found in the GCUP. The uranium is typically deposited as uranium oxides and, to a lesser extent, uranium silicates. Uranium concentrations range from 0.04 to 0.25 percent; the deposits generally range in size from 0.5 to 20 million pounds.

Most roll-front deposits that are below the water table can be mined through in-situ recovery (ISR, see pages 28 and 30). This is particularly true of well-defined, well-graded, and well-sorted fluvial sandstones that have good porosity and permeability and are in confined aquifers bounded by impermeable clays. These conditions make it easier to manage the fluids and retrieve the uranium economically. Roll-fronts that are not saturated are typically near the surface and can be mined by open-pit methods; most such deposits were mined during previous mining booms.

Tabular sandstone deposits are elongated, blanket-like deposits usually less than 8 feet thick, average more than 0.17 percent uranium, and have sharp ore-waste rock boundaries. The largest deposits in New Mexico contain more than 30 million pounds of uranium oxide (U3O8). Uranium minerals in these deposits are intimately associated with organic detritus, often humates, an insoluble organic material that makes the deposit unsuitable for recovery by ISR. Thus most of these deposits are mined by conventional open-pit or underground methods. Some tabular deposits are reworked over time by groundwater, resulting in the formation of redistributed ore bodies that may be amenable to ISR. Tabular sandstones occur mainly in the CPUP; some deposits also are found in the BRUP.

Solution-collapse breccia pipes form in karstic terrain consisting of limestone and calcium-rich sandstone and shale. Dissolution caused portions of the rocks to collapse, forming vertical pipes. A mineralized breccia pipe ranges from 1,000 to 1,800 feet deep, has a vertical height of up to 600 feet, and is typically 200 to 400 feet in diameter. They are highly fractured and filled

with rock fragments from the collapsed overlying layers. Uraninite, a reduced uranium oxide ore mineral, accumulates within the permeable column of broken rock, forming a cylindrical, vertical deposit. Mineralizing fluid apparently flows upward, but the precipitation front remains stationary, unlike the often-migrating roll-front deposits.

Location of uranium provinces in the West (modified from Finch, 1996).

TEXAXX S

MONTANAA

NEVADA

IDAHO

CALLIFOORRNIA

OREGON

KAKK NSAS

NEBRARR SKAKK

HHINGTOON

OKKLLLAAHOMA

SSOOUUTHDAKKOOTTA

NNOORTHDAAKKOTA

MINNESOOOTAA

IOOOWWWWWAAWW

MISSOURRRRIIIIII

A

N A

O

Mexico

Canada

PacificOcean

Basin and Range

Uranium Province

Rocky Mountain andIntermontaneBasins UraniumProvince

Colorado PlateauUranium Province

Gulf CoastUraniumProvince

50°

40°

40°

30°

30°

2 0°

-100°

-100°

-110°

-110°-120°-130°

0 250 500Miles

Legend

Major Uranium ClustersRoll-front sandstoneTabular sandstone

Vein

Collapse-breccia pipeVolcanicLimestone

Map compiled by: Kris Cope

see Geology, page 34

Pho

to: A

REV

A In

c.


The Grants uranium district in northwestern New Mexico was a prolific producer of uranium

from the 1950s to the early 1980s. Most of the uranium mining and milling activities occurred prior to the development of environmental laws and regulations aimed at protecting human health and the environment. As a result, conventional industry practices employed during this period caused extensive groundwater contamination throughout the area. Adequately addressing groundwater contamination has been complicated by the extensive mining operations in the area and the large-scale dewatering that was required to remove the ore.

HistoryThe Grants district (see map) is a large area within the San Juan Basin, extending from east of Laguna to west of Gallup. It comprises eight subdistricts that contained hundreds of mines, including 112 that produced at least 200,000 pounds of uranium oxide, U3O8. From 1948-1980, the Grants district yielded more uranium than any other in the United States. More than 340 million pounds of U3O8 were produced there from 1948-2002, accounting for 97 percent of the total production in New Mexico and more than 40 percent of the total U.S. production (McLemore, 2002).

Most uranium production in New Mexico has come from the Morrison Formation, mainly from the Westwater Canyon Member, a significant aquifer in the area. Therefore, the formation had to be

partially dewatered in order to remove ore. Prior to the mid-1970s, water generated during dewatering activities was discharged to the surface and allowed to flow into natural water courses without any treatment. These mine water flows were a significant source of contamination of sediments, alluvial aquifers, and even deeper aquifers in areas of faulting.

Groundwater in the Grants district was also contaminated by other mine-related activities, including seepage from evaporation ponds and mill-tailing ponds, mine-stope leaching, leaching of waste materials stored on the surface, and underground-mine disturbance related to removal of ore, which introduced oxygen into the system, causing geochemical reactions that dissolved contaminants into the groundwater. Contaminants present in the groundwater system include molybdenum, selenium, 226+228radium, sulfate, total dissolved solids, and uranium.

Regulatory FrameworkAll conventional underground and open-pit uranium mines in New Mexico closed by 1989, due mainly to economic factors. The Federal Clean Water Act was passed in 1972 and New Mexico followed suit by enacting the New Mexico Water Quality Act in 1974 and

accompanying regulations in 1977. These regulations addressed, among other things, discharges from uranium mines and mills. However, by this time the uranium market was already deteriorating and most mines and mills ceased operations shortly thereafter. Therefore, the majority of uranium mining and milling operations in New Mexico predated environmental laws and regulations.

When New Mexico’s regulations were promulgated in 1977, a groundwater-protection standard for uranium of 5 milligrams per liter (mg/l) was established; at that time, neither the World Health Organization (WHO) nor the U.S. Environmental Protection Agency (EPA) had established a standard. In 1993,

Groundwater RemediationJerry Schoeppner – New Mexico Environment Department

New Mexico

Churchrock—Crownpoint

Smith Lake

Grants

Laguna

Chaco Canyon

Nose Rock

Ambrosia Lake

Marquez

BarnabeMontaño

Morrison Formation (Jurassic)sandstone uranium deposits

Other sandstone uraniumdeposits

Limestone uraniumdeposits

Other sedimentaryrocks with uranium

Albuquerque

Grants uranium district, San Juan Basin, New Mexico. Polygons outline approximate areas of uranium mine subdistricts (from McLemore, 2007).

from Uranium Mining in New Mexico

St. Anthony’s Pit, New Mexico. See water quality analysis of pit lake water in table, opposite page.


WHO recommended that the limits for radiological characteristics for uranium be used until adequate short- and long-term studies on the chemical toxicity of uranium could be completed. Based on these limits, the equivalent for natural uranium is approximately 0.14 mg/l. In an addendum to the WHO Guidelines, published in 1998, a health-based guideline value of 0.002 mg/l was established (WHO, 2004). In 2000, EPA issued its first uranium drinking water standard of 0.03 mg/l; this standard is higher than the WHO standard because it was derived using both health data and economic considerations. Finally, in 2005 New Mexico revised its uranium standard to 0.03 mg/l to be consistent with EPA.

Challenges of Groundwater

RemediationAddressing groundwater contamination in the Grants uranium district is complicated by several factors: 1) extensive mining and related dewatering activities have created regional, rather than localized groundwater contamination; 2) underground workings are so extensive that they connect one mining operation to another, making it difficult to determine responsibilities; 3) many different companies operated mines throughout the Grants uranium district, and many no longer exist; 4) much of the groundwater quality data are dated and large data gaps exist; 5) premining groundwater data are insufficient to establish cleanup criteria; 6) the uranium standard has only recently been established and has been revised over time; and 7) proposed new operations could further cloud the issue of background and cleanup criteria.

Because groundwater is contaminated throughout the district, a regional solution is required. This may take the form of allowing the groundwater system to recover to premining levels to restore geochemical conditions (which could take hundreds to thousands of years), implementing an engineering solution that may involve extraction and treatment to drinking water standards (and possible sale of the resource to offset reclamation costs), or some other solution that lies between these two extremes. Any engineered

solution would require participation from many different parties, which would likely slow down the process with litigation.

Obviously, addressing groundwater contamination in the Grants uranium district is very complicated. It will take a great

deal of assessment work, coordination, and funding that is currently lacking. It also will inevitably take a long time, which raises the issue of how to protect the public from potential health impacts of drinking contaminated water. Very few residents live in the most contaminated portions of the district, but those that do rely on domestic wells for their primary drinking water supply. A combination of public education and individual water treatment systems may be the only short- and long-term solutions.

One of the few encouraging aspects is that, based on groundwater modeling, recovery of groundwater levels will take upwards of

see Remediation, page 34

Pit lake contaminantsRange* of samples collected

(2004-2005)Surface-water

standard*Groundwater

standard*

molybdenum <0.0055 – 0.020 none 1.0

selenium <0.015 – 0.035 0.05 0.05

uranium 4.2 – 5.3 none 0.03

total dissolved solids 23,000 – 32,000 none 1,000

sulfate 16,000 – 25,000 none 600

gross alpha 3,050 – 4,590 pCi/l 15 pCi/l none

226+228radium 11.59 – 24.83 pCi/l 30 pCi/l 30 pCi/l

* All measures in mg/l unless otherwise noted. pCi/l = picoCuries per liter

Water quality in the St. Anthony’s uranium mine pit lake compared to standards. Comparison for compliance is against surface-water standards for the designated use of livestock watering, wildlife habitat, and aquatic life. Concentrations of some contaminants are high, but lacking surface-water standards, are not out of compliance. If pit lake water were to flow into the groundwater system, it would have to meet groundwater standards outside the lake.

One of the few encouraging aspects is that recovery of groundwater levels will take upwards of several hundred years.


32 33 3431

35

3029 28 27

26

2322

2120

19

18 17 1615

14

111098

7

363534

252627

242322

131415

1211

10

23

T 14 NT 13 N

0 1 MILE

Mine workingsEstimated location of mine workings

N

Ambrosia Lake

Philips Petroleum Ambrosia Mill

Kermac Nuclear FuelsProcessing Plant

Uranium mine closure in Ambrosia Lake Valley, just east of Gallup, New Mexico, presents challenging

technical and regulatory issues. Because mining began before current regulatory requirements were established, data to define historic conditions are sparse; the original concentrations of groundwater contaminants in the mineralized zone are unknown. Establishing benchmark numerical values for background/baseline constituents of concern in groundwater is now critical to mine-site closure or permitting. Further, the influences on groundwater quality in the area’s underground mines are varied and complex and benchmarks that could demonstrate successful remediation are poorly defined.

For more than 30 years beginning in the mid-1950s, at least 14 uranium mines were developed in the valley, at depths

up to 2,500 feet below the surface. Uranium was mined by conventional room and pillar methods, resulting in an extensive network of mine workings at each mine. However, uranium

deposits ordinarily do not stop at section boundaries, so most of the workings are interconnected from one end of the valley to the other over an area approximately 10 miles long and three miles wide.

Uranium ore was extracted from the Westwater Canyon Member (WCM)

of the Morrison Formation. The WCM is composed of alternating, lens-like sandstone and mudstone interbeds, with ore deposits ranging from a few feet in length and thickness to mile-long masses over 30 feet thick. The scale of interbedding ranges from inches to a few tens of feet. Pyrite, a highly reactive sulfide mineral, is present in amounts ranging from none to two percent of the ore zone and is variable on the scale of feet or even inches.

Large-Scale DewateringPast mining activities necessitated large-scale dewatering: more than 250,000 acre-feet of water was pumped from Ambrosia Lake Valley. The U.S. Geological Survey has estimated that the potentiometric surface of groundwater in an 80-square-mile area in the valley has been drawn down

Finding Benchmarks at Uranium Mine SitesDaniel W. Erskine and Cynthia Ardito – INTERA Inc.

I N D E X M A P

SITE

The mine workings in Ambrosia Lake Valley cover some 30 square miles in northwest New Mexico.

The area affected by drawdown of 100 feet or more is estimated to be on the order of 1,000 square miles.


more than 500 feet from dewatering. The area affected by drawdown of 100 feet or more is estimated to be on the order of 1,000 square miles.

Most mine dewatering stopped by 1986 and water levels are now recovering. Estimates of the time required to fill the regional cone of depression range from several hundred to several thousand years. The water does not simply rise up uniformly, but is complicated by dipping strata and geologic structures, and diverted by the vast network of mine workings with gradients in all directions. Some deeper mine workings on the southeast end of the ore trend already are flooded but it will be hundreds of years before shallower workings on the northeast end are filled, causing the center of the cone of depression to migrate from the southeast to northwest over time. Thus flow paths will continue to change as groundwater flows back into the area, blurring the traditional hydrogeologic concept of upgradient/downgradient.

Water Quality Impacts

of DewateringBefore mining began, uranium ore zones were anaerobic; pyrite, uranium, and other metals were relatively stable. But as dewatering progressed, the ore zones were exposed to oxygen and pyrite oxidized, producing sulfate ions and acid. The production of sulfate increased the total dissolved solids concentrations in groundwater within and discharged from the mine workings, and the increased acidity dissolved the metals, including uranium, selenium, and molybdenum, causing their concentrations in groundwater to increase as well.

As the mine workings become flooded again, oxygen will be consumed and the subsurface conditions will return to a more reduced state. This change will favor the precipitation of metals, removing them from groundwater. However, because of the complexity of the underground workings and changing flow paths, predicting the timing, degree, and location of water quality changes is difficult.

Finding a BenchmarkThe presence of ore deposits at Ambrosia Lake Valley suggests that the regional groundwater quality was highly variable even before mining began. The fact that no pre-mine water quality data were collected compounds the challenge of establishing benchmark values—water quality standards to be achieved at specific locations—for remediation efforts. Yet determining the best estimates of these values is critical: a small change in a benchmark can translate to an enormous change in the cost of remediation for an operator.

Lack of pre-mine background data is a challenge to determining what the benchmark values should be. Changes in flow direction, variability in aquifer matrix materials and their states of oxidation, and uncertainties inherent in trying to predict flow in a complex void space also make defining where benchmarks should be applied difficult. Any benchmarks that might be set as closure goals will likely not be as simple as traditional upgradient and downgradient monitoring of water quality parameters.

Regulatory StatusResolution of these issues will require the participation of both regulators and mine operators to formulate a reasonable and effective strategy to protect human health and the environment. Both groups generally agree that pump-and-treat options for remediation are not feasible because this would continue to allow oxygen into the workings, causing continued leaching of constituents from

the aquifer matrix and no improvement in groundwater quality. They also agree that the existing cone of depression is causing the degraded groundwater to flow toward the center of the drawdown, thereby restricting any impacts to the area surrounding the mines. However, a path to regulatory compliance is uncertain.

From a regulatory perspective, long-term monitoring of groundwater is an absolute minimum requirement, but the question of what and where to monitor is currently unclear. Constituents such as sulfate, uranium, and selenium clearly exceed state standards, but their concentrations prior to mining are highly uncertain.

At present we are left with more questions than answers. Even if pre-mining water quality conditions were known, where should a compliance location be established to measure concentrations? In general, flow will be contained within the mined area for a long time. However, flow directions will change in complex ways over time, related to infilling of the complex void space represented by the mine workings. Should monitoring locations be upgradient and downgradient relative to the existing flow regime, or to the one that will be established when recovery is complete in several hundred years? If the former, what information will monitoring provide? Add to this the fact that there is renewed interest in reopening some of the mines in question and you have a regulatory conundrum on a scale equal to that of the technical complexities we have described.

Contact Dan Erskine at [email protected].


Surface and underground mining of uranium occurred in the United States throughout much of the

20th century, mostly in Colorado, Utah, New Mexico, and Wyoming and on tribal lands. Most uranium production was carried out under contract with the Atomic Energy Commission (AEC) for use in defense research and weapons development. Decades of unregulated uranium-ore processing resulted in uncontrolled mill tailings ponds and piles, and contaminated fluids discharged to surface drainages and groundwater. Many facilities were abandoned after government contracts were fulfilled, leaving the land and groundwater contaminated. Other facilities continued to operate, largely to support the nuclear power industry.

Federal Responsibilities AssignedBefore the 1950s, the federal government imposed few regulations on the mining and processing of uranium. In 1954, AEC was given regulatory authority over the production and use of nuclear materials. Its authority began when ores were received at processing mills, leaving other entities such as state agencies to regulate uranium mines.

Potential hazards at the ore-processing facilities from direct gamma radiation, radon gas emissions, and dissolved contaminants in groundwater and surface water began to be recognized in the 1960s, but it was not until 1974 that Congress called for a systematic inventory of inactive mill sites. Thousands to millions of cubic meters of contaminated materials were identified at individual sites; contaminated land areas ranged from about 25 to 600 acres. Off-site locations were often affected by windblown contamination. Seepage from tailings piles and leaky evaporation ponds resulted in groundwater contaminant plumes, typically extending from 600 to 3,000 feet or more. Aqueous-

phase contaminants consisted mostly of inorganic constituents that included arsenic, cadmium, chromium, lead, molybdenum, nitrate, selenium, radium isotopes, and uranium. Uranium concentrations in groundwater ranged from less than 0.01 milligrams per liter (mg/l) to 10 mg/l.

In 1978, Congress passed the Uranium Mill Tailings Radiation Control Act (UMTRCA), directing government agencies to stabilize, dispose of, and control materials contaminated by milling operations in a safe and environmentally sound manner (it does not address mine sites; see sidebar). Title I of UMTRCA required the Department of Energy (DOE) to complete remediation at the 22 then-inactive uranium mill sites and Title II directed the Nuclear

Regulatory Commission (NRC) to regulate active facilities. DOE is the long-term custodian for both types of sites after cleanup and decommissioning is complete.

UMTRCA directed the Environmental Protection Agency (EPA) to develop cleanup standards for Title I sites. In 1983, EPA’s final cleanup and disposal standards for inactive mills were challenged in court and upheld except for the groundwater standards. As a result, the surface cleanup program moved forward, and groundwater cleanup was deferred until groundwater standards could be finalized. DOE established the Uranium Mill Tailings Remedial Action (UMTRA) Project and began work on the UMTRA Surface Project in 1983. Processing sites were remediated in accordance with EPA standards for contaminated buildings, tailings, and soils. Tailings were placed in on-site or off-site engineered cells for final disposal. Low-permeability radon barriers (clay or silt) covered the disposal cells, typically overlaid by a layer of granular bedding material to provide a capillary break, and surface layers of rock for erosion protection. Drain systems for collecting tailings leachate were installed at most disposal sites, and ditches were frequently used to divert surface water away from the cells.

Groundwater Standards SetEPA’s groundwater standards for cleanup and disposal of inactive uranium-ore processing sites were finalized in January 1995 and formed the basis for implementing the UMTRA Ground Water Project. The final regulations established numerical groundwater protection standards for uranium, molybdenum, and other metals common to processing sites along with constituents known to occur there, such as lindane and nitrate. The regulations also provide for the use of background concentrations (in groundwater unaffected by uranium-ore processing), alternate

DOE Remediation of Uranium Mills: A Progress Report

David M. Peterson, Laura E. Cummins, and Judith D. Miller − S.M. Stoller Corporation andRichard P. Bush − U.S. Dept. of Energy Office of Legacy Management

Title I SitesTitle II Sites

Locations ofUMTRA sites currently managed by the U.S. Department of Energy Office of Legacy Management.

Seepage from tailings piles and evaporation ponds resulted in groundwater contaminant plumes extending 3,000 feet or more.


concentration limits, or supplemental standards for groundwater protection. Alternate concentration limits may be higher than maximum concentration limits or background but are still protective of human health and the environment. Supplemental standards apply to aquifers of naturally poor quality or low yield.

DOE’s Programmatic Environmental Impact Statement for the UMTRA Ground Water Project (DOE, 1996) provided a framework for characterizing groundwater at the inactive processing sites, assessing potential risks, and selecting an appropriate strategy for meeting EPA groundwater standards. Remediation strategies were selected in consultation with NRC, the states involved, and tribes where applicable.

Strategies for Meeting ComplianceThree general compliance strategies were identified: no action, natural flushing, and active remediation. The no-action alternative was applied to sites where groundwater constituents did not exceed background concentrations, maximum concentration limits, or supplemental standards; it was also considered for sites where alternate concentration limits could be established that were protective. Active remediation was applied to sites needing relatively aggressive groundwater cleanup methods to achieve standards, such as manipulation of hydraulic gradients, groundwater extraction and treatment, or in-situ remediation. Natural flushing (similar to what EPA calls monitored natural attenuation) was applied to sites where

natural attenuation processes are considered a viable route of achieving groundwater standards within 100 years. Groundwater modeling is generally required to support a natural flushing decision, and performance monitoring of the system is required to measure progress in meeting cleanup goals.

Surface remediation is considered complete at all 22 of the original Title I processing sites. DOE has responsibility for managing and monitoring the long-term integrity of 19 Title I disposal cells. Groundwater remediation is considered complete for 12 Title I processing sites where a no-action alternative groundwater compliance strategy was selected, but some continue to be monitored. For 10 Title I processing sites, active remediation

see DOE, page 35

While UMTRCA and its related

programs address problems related

to uranium mill sites, who looks after

the more than 4,000 mines with a

history of uranium production that

are listed in EPA’s database? Mines

fall under the purview of several EPA

statutes, including the Clean Water,

Safe Drinking Water, and Clean Air

acts and various programs under

them, for which most states and

many tribes have primary enforcement

responsibility. Mines on federal lands

also are subject to requirements

enforced by Department of Interior

agencies.

Recently, EPA completed a study of

Technologically Enhanced Naturally

Occurring Radioactive Materials

(TENORM) from uranium mining

(2008), which examined the nature

and risks of mine wastes. Mine waste

classified as TENORM includes ore

of insufficient quality to be mined,

Meanwhile, Back at the Mine Sites

waste rock, drill core and cuttings, and

mine and pit water. The volume of such

waste generated by open-pit mines far

surpasses that of underground mines,

and has been estimated to be three

billion metric tons nationwide.

According to EPA, most abandoned

uranium mines are likely to have elevated

concentrations of uranium and radium,

as well as other constituents such as

arsenic, but two factors reduce the risk

to most human populations: location and

climate. Most abandoned mines are on

federal land, where primary exposure is

through short-term recreational activities

that entail only minimal health risk. And

many are in areas with low precipitation

and deep groundwater, so the risk of

groundwater contamination is low, at

least for the short term (tens of years).

In contrast, those who live close to mine

sites and use mine waste in building

materials (as occurred on the Navajo

reservation) face substantial health risks.

Federal, state, and tribal agencies

have worked to prioritize remediation

and closure of abandoned mine sites,

but budget constraints will preclude

remediation of them all. Hundreds of

small mines likely will be left alone. But

at the other end of the scale, over 500

abandoned uranium mines have been

identified on the Navajo Nation, and

earlier this year EPA, the Department

of Energy, Bureau of Indian Affairs,

Indian Health Service, and the Nuclear

Regulatory Commission finalized

a five-year plan for remediation of

these mines. Several removal actions

addressing contaminated sites and

structures have been undertaken

on the reservation through EPA’s

Superfund program.

Reference

EPA, 2008. Technologically Enhanced Naturally Occurring Radioactive Materials from Uranium Mining, vols. 1 & 2, www.epa.gov/rpdweb00/tenorm/pubs.html.

1950 20001960 19831954 1978 1995 1996Prior to 1950, few government regulations

Atomic Energy Act of 1954

Potential hazards begin to be recognized

1974Congress callsfor systematic

inventory of inactive mill

sites

Congress passes UMTRCA

UMTRCA directs EPA to develop cleanup standards for Title I sites

EPA’s groundwater

standards set; form basis for

UMTRA Ground Water Project

Programmatic Environmental Impact Statement for the UMTRA Ground Water Project

Ongoing DOE monitoring of Title I and II sites


As an alternative to conventional underground or surface mining operations, uranium deposits

increasingly are being mined by in-situ recovery (ISR). ISR works well for redistributed uranium present as a coating on the sand grains in many sandstone deposits because the uranium is relatively soluble when subject to oxidizing conditions. Where the hydrogeology of the deposit is favorable, such as in permeable, saturated, confined sandstone deposits with relatively flat-lying beds and low hydraulic gradients, uranium can be recovered by circulating a solution through the deposit rather than by bulk excavation. Typically, 60 to 80 percent of the uranium in the deposit can be recovered. ISR offers many advantages over conventional mining, including a lack of tailings piles, minimal disruption of the land surface and thus minimal surface reclamation needs, reduced labor requirements, and overall lower costs.

About 30 ISR operations and numerous pilot projects have been licensed and operated in the United States since the early 1970s, particularly in Nebraska, Texas, and Wyoming. New operations are proposed in New Mexico, Texas, and Wyoming.

Running the Formation

Process BackwardsISR makes use of the hydrologic and geochemical properties of a uranium-bearing sandstone aquifer to recover uranium by essentially running backward the process that formed the uranium deposit in the first place. As described by Yancey (page 20), roll-front uranium deposits form in sandstone when oxidized water carrying dissolved uranium encounters a reducing zone in the aquifer, where the uranium precipitates and accumulates over time (see diagram, right).

In ISR, local groundwater fortified with sodium bicarbonate or gaseous carbon dioxide and oxygen (the “lixiviant”) is

injected into the ore body. Extraction wells draw the lixiviant through the formation, oxidizing and dissolving the uranium, and back to the surface, where the solution undergoes ion exchange to remove the

uranium. The uranium-depleted water is returned to the wellfield for refortification with oxygen, then recirculated back to the injection wells. This process continues until no more uranium can be economically recovered. Sets of injection wells are paired with extraction wells to ensure good flow through the deposit; their arrangement is based on the hydrogeologic conditions of the site (see page 30).

Production wells are operated at the maximum continuous flow rate achievable for the deposit. Flows typically range from 20 to 100 gallons per minute. In addition to the use of paired wellfield injection/extraction patterns, injection into the wellfield is maintained at a flow rate around one percent less than the extraction rate to create a hydraulic gradient that draws groundwater outside the ore zone into the wellfield and keeps the lixiviant from migrating outside the production zone. Flow rates for the injection and production wells are monitored regularly to assess operational conditions and mineral royalties.

The groundwater is extensively monitored to demonstrate that the lixiviant remains within the production zone. Monitor wells are completed in the ore-bearing aquifer, encircling the wellfield at about 400 feet from the peripheral production or injection wells and around 400 feet apart, according to industry convention (and Texas standards). Monitor wells are also completed in the aquifers overlying and underlying the ore zone.

Recovering the UraniumThe uranium-rich lixiviant is piped from the wellfield to the processing plant,

then pumped through

In-Situ Recovery of UraniumMark S. Pelizza – Uranium Resources Inc.

ISR recovers uranium by essentially running backward the process that formed the uranium deposit in the first place.

water table

sandstoneoxygenated water

roll-fronturaniumore body

sand & gravel

clay mudstone

lower clay

reducingenvironment

ISR is suitable for many roll-front uranium deposits, which form at the boundary of oxidizing and reducing subsurface environments.


ion exchange resin columns where the uranium is recovered and further processed into yellowcake, a uranium concentrate. Uranium-depleted water from the resin columns may be filtered to remove particulates before recirculation.

In cases where uranium ore deposits are too small to support a full-service process facility, or portions of the wellfield are so distant that piping water is not practical, remote ion exchange (RIX) may be employed. RIX uses ion exchange columns at the site to recover uranium from the leachate stream, but the uranium-loaded resin is trucked to a central plant where the uranium is recovered. The stripped resin is returned to the RIX site for reuse.

When There’s No More UraniumOnce the economic recovery limit of a mine area is reached, lixiviant injection is stopped and the affected groundwater is treated to return its quality to levels defined by regulatory standards. This is generally accomplished by circulating nonfortified groundwater through the production zone using the same injection-extraction wellfield configuration as was used during production. The extracted water is purified in an ion-filtration process such as reverse osmosis treatment (RO) and the clean water is recirculated. The concentrated brine byproduct of RO is about 25 to 35 percent of the feed volume.

Alternatively, the wellfield may be “swept” by continuously pumping water from the extraction wells, drawing groundwater in from beyond the mineralized zone to replace the pumped fluid. Pumping continues until the desired water quality is attained. Water quality improvements by this method are achieved more slowly than by RO, and large amounts of groundwater are consumed. After any uranium in the pumped water is recovered, the water is disposed of in deep waste injection wells, but well capacity limits the rate of restoration.

Aquifer quality restoration goals are initially established by state water-quality regulators, usually on a parameter-by-parameter basis, with the primary goal of restoring all parameters to average

pre-mining baseline conditions. Although the ISR process does not introduce new chemical species to the groundwater system, it does elevate the concentrations of some that were already present, such as calcium, sodium, chloride, bicarbonate and uranium. If it is not feasible to return all parameters to their baseline concentrations, the secondary goal of aquifer restoration is to return water quality to the maximum concentration limits as specified in U.S. Environmental Protection Agency primary and secondary drinking water regulations. If that is not feasible, the operator must demonstrate to the regulatory agency that leaving the parameter at the higher concentration will not threaten public health and safety, and that, on a parameter-by-parameter basis, water use will not be significantly degraded from its pre-mining condition.

ISR operations produce small amounts of solid wastes and predominantly liquid effluents. Solid wastes such as contaminated equipment, resin, and pond sediments are generally transported to licensed facilities, and liquid waste

from the wellfield, process circuit, and aquifer restoration usually is injected into deep waste disposal wells.

see In-Situ, page 34

Chemistry of Typical Uranium-Rich Lixiviant

(milligrams/liter unless noted)

calcium 100 - 350

magnesium 10 - 50

sodium 500 - 1600

potassium 25 - 250

carbonate 0 - 500

bicarbonate 800 - 1500

sulfate 100 - 1200

chloride 250 - 1800

silica 25 - 50

total dissolve solids 1500 - 5500

uranium 50 - 250226radium (pCi/l) 500

conductivity (μS/cm) 2500 - 7500

pH 7 - 9

pCi/l = picoCuries/liter

μS/cm = microsiemens/liter


In 1990, 55 percent of world’s uranium production came from conventional open-pit or underground mining

operations, but by 1999 the volume had decreased to 33 percent (World Nuclear Association, 2008). Conventional mining produces tailings, runoff, and considerable land disturbance—all requiring significant rehabilitation. With in-situ leach mining methods (see diagram at right), disturbance is reduced because only multiple boreholes are drilled for recovery. Rehabilitation is much simpler, consequently the number of in-situ uranium mining operations is steadily increasing.

Most in-situ mining projects are operated at sites with small ore deposits, lower-grade ore deposits, or where ore bodies are deep. Distance from drinking water supplies or environmentally sensitive ecosystems is also considered. Sites with large deposits can be divided into several smaller sections that are mined one at a time, allowing the operator to optimize the process.

Hydrogeologic AnalysisBasic to an in-situ mining operation is a thorough understanding of the site’s hydrogeology, particularly the degree to which fluid movement can be predicted and controlled. The hydrogeology of each site is specific; in-situ mining may not be practical for every uranium deposit. In determining feasibility, important questions to be answered include: Is uranium deposited in the saturated zone with sufficient available drawdown? Do the upper and lower confining units of the aquifer provide enough vertical confinement for the lixiviant (leaching solution)? Is the formation’s hydraulic conductivity high enough for wells to achieve reasonable well productivity and injectivity?

Well productivity and injectivity are directly proportional to the values of formation transmissivity. Hydraulic conductivity, defined as transmissivity divided by

aquifer thickness, is generally used as the measure for well productivity and injectivity. In a typical well-field setting, in order to maintain a minimum well flow of 10 to 25 gallons per minute, a hydraulic conductivity of one foot per day would be considered the minimum value suitable for in-situ mining.

The storage coefficient, a ratio of the water pumped to the volume of cone of depression, is important when estimating the radius of influence of pumping and injection. Typically, unconfined and confined aquifers have storage coefficients ranging from 10 to 25 percent and from 0.001 to 0.1 percent, respectively.

Once hydrogeologic feasibility of ISR has been determined, engineers can increase the economic feasibility of the operation and minimize the associated environmental effects by addressing three major aspects. Recovery process design influences how efficiently uranium is removed; well-field design optimizes resource recovery and containment; and monitoring programs provide baseline data and detect potential leakage from the site.

Recovery Process DesignThe design of the recovery process influences how efficiently the minerals can be recovered from underground formations and minimizes the time and cost to complete the recovery. The design usually begins in the laboratory, proceeding from batch tests to column tests and then stream-tube tests. Results show the distance that the lixiviant can travel underground before losing its leaching ability. These data are essential for determining spacing between production and injection wells; this spacing generally ranges from 30 to 80 feet.

A key indicator for extraction efficiency is the number of pore volumes of fluid required to recover significant amounts of uranium from an aquifer. In general, mining companies use seven to 15 pore volumes to estimate the economical value of an in-situ mining operation. The larger the number, the longer it takes and the lower the peak mineral recovery concentration.

Well-Field DesignAreal sweep efficiency is defined as the percentage of an area covered by injected

well-field mechanics forin-situ uranium miningShao-Chih (Ted) Way – In-Situ Inc.

Schematic of the in-situ mining process.

Controlling the flow pattern ensures the peak mineral concentration will be high and the mineral recovery time short.


solution at the time of breakthrough. Several standard well-field patterns are commonly used (see diagram above). Sweep efficiency varies with well configuration. For example, staggered line drive, wth sweep efficiency of 74 to 78 percent, is a much better well-field pattern than direct line drive, with sweep efficiency of 55 to 60 percent, although these two patterns have the same number of wells.

Controlling the flow pattern in such a way that the breakthrough times for all streamlines will be similar ensures that the peak mineral concentration will be high and the mineral recovery time short. Ideally, all streamlines would break through at the same time, meaning 100 percent areal sweep efficiency, but that is not possible.

In order to ensure containment, the total pumping rate is generally 1 to 3 percent higher than the total injection rate. The idea is to create an inward flow gradient and to control lixiviant flow. The effect of regional groundwater flow on well flow rates and in-situ mining operations is usually negligible since regional groundwater flow is very slow, generally less than 50 feet per year. A groundwater model is usually developed and its streamlines are examined as part of the well-field design process.

Well productivity and injectivity provide a good indication of the type of basic well-field pattern to be considered. Productivity is limited by the available drawdown, and injectivity is limited by the fracture pressure. If well-injection pressure exceeds the pressure at which hydraulic fractures would begin to develop, short circuits could form between injection and production wells.

In estimating well productivity and injectivity, well efficiency should be

considered. Typically, most wells operate with 60 to 80 percent efficiency. One hundred percent efficiency is usually not possible because of well-bore damage during drilling and well-screen plugging due to chemical deposits during operation.

Flow reversal: Inevitably, after a period of production, the mineral recovery rate shows a marked decline. This is because it is difficult to recover uranium in the areas between two production wells and between two injection wells. When decline occurs, switching some wells from production to injection, or otherwise altering the flow pattern, can boost recovery.

Groundwater Monitoring ProgramA groundwater monitoring program is essential for protecting areas surrounding the mining operation. This consists of a ring of production-zone monitor wells located 400 to 500 feet (depending on regulatory requirements) outside the production zone, with spacing between wells less than 500 feet. Additional monitor wells overlaying and underlying the aquifer are needed to monitor vertical leakage.

An inner ring of warning monitor wells is recommended (though not required by law) as an early warning system for potential leakage (see diagram below).

In-situ uranium mining uses groundwater from the ore body fortified with a complexing agent and an oxidant. Because the leaching process alters the pH of the formation water, pH is the best parameter to monitor for potential leakage. Conductivity and groundwater level are also monitored as indicators of potential leakage. Often these three parameters are measured hourly and are used as a field screening tool for detecting the presence of contamination. The analyses of uranium and other appropriate parameters are included in the weekly and monthly water sampling programs. If abrupt changes in the water quality indicators are observed, additional water samples are collected immediately and analyzed.

Bottom Line: Parameters Are KeyOther than a site’s uranium reserves (the amount of recoverable uranium), hydrologic characterization of the formation is the most important consideration in determining the economic feasibility of an in-situ uranium mining operation. Constant-rate pumping tests, sometimes combined with slug tests, are used to define average hydrologic conditions.

A proper well field pattern with the optimum areal sweep efficiency reduces the duration of the operation, lowers costs, provides better control of lixiviant flow, and minimizes the area of potential leakage. A combination of real-time monitoring of key water-quality indicators (pH, conductivity, and water level) and scheduled groundwater sampling is essential to a successful groundwater monitoring program.

Contact Ted Way at [email protected].

ReferencesAnderson, W.C., ed., 1998. Innovative Site Remediation

Technology, Design and Application, Liquid Extraction Technology, Amer. Acad. of Envir. Engrs.

Craig, F.F., Jr., 1971. The Reservoir Engineering Aspects of Waterflooding, Soc. Petrol. Engrs of Amer. Inst. of Mining Engrs.

World Nuclear Association, July 2008. World Uranium Mining, www.world-nuclear.org/info/inf23.html.

five-spot seven-spot inverted seven-spot

direct linedrive

staggeredline drive

production well

injection well

production wellinjection well

monitor wellwarning well

production zone monitorwell ring

overlying aquifermonitor well

underlying aquifermonitor well

productionzonewarningwell ring

400 feet

500 feetmax.

Common well-field design patterns.

Typical well placement for an ISR operation.


Climate Tools for Water ManagersMike Crimmins – University of Arizona. This department is provided by the Institute for the Environment and Society at the University of Arizona. Visit www.ispe.arizona.edu.

Tracking Precipitation Across the Nation

Source: National Weather Service

Access: water.weather.gov

The National Weather Service (NWS) has developed a new web tool to track precipitation amounts at various timescales across the United States. The tool displays daily precipitation values on a four-by-four kilometer grid estimated from multiple sensors including NEXRAD radar, surface rain gauges, and satellite precipitation estimates. The gridded national dataset is produced by combining precipitation estimates produced regionally at twelve NWS River Forecast Centers across the United States. In the mountainous West, where radar and rain gauge

coverage are limited, an additional step of interpolation and comparison to historical data is also incorporated to improve precipitation estimates.

The web tool allows users to view a national composite map or to zoom into regions, states, and county-level areas over multiple time periods, including for the previous day and precipitation totals over the last 7, 14, 30, or 60 days. Archived data are available back to 2005 with monthly estimates of departure from normal and percent of normal precipitation. Raw data files can also be downloaded for research purposes.

Continuous, national-scale precipitation estimates available through this web tool can assist in tracking hydroclimatic events like floods and drought over large areas. NWS welcomes your suggestions and comments to continue improving and enhancing the web tool.

Visit water.weather.gov.

Departure from normal of 60-day precipitation over New Mexico and the surrounding area on Sept. 9, 2008. Some areas received up to 16 inches more than normal during the 2008 monsoon season.


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that I have attended in years.

- S.C. Blauvelt, P.G., Vice President & Director of Regional Operations, Penn E&R, Inc.


Aquifer Impacts?Before ISR even begins, the uranium ore-bearing aquifer contains naturally occurring 226radium, 222radon, and other uranium-decay products at concentrations exceeding EPA drinking water standards (see table below). Nonpotable water such as this can be exempted as an underground source of drinking water under EPA’s Safe Drinking Water Act, and the field of injection and extraction wells can be permitted for Class III underground injection control (UIC) activity. UIC regulations require ISR operations to be designed to produce only from the exempted area, and monitoring must demonstrate that the leach solution is contained within the ore zone. Monitoring parameters are typically chosen that are high in concentration compared to surrounding ambient groundwater, are robust, and may be rapidly analyzed at site laboratories. Parameters such as conductivity, chloride, bicarbonate, sulfate, and uranium are common. Restoration must be completed before monitoring ceases, to prevent regional contamination.

Construction, operation, monitoring, and reporting at ISR sites in the United States have been highly successful in ensuring that leach solution remains confined to the exempted ore zone, as required by UIC regulations. As a result of these practices and the fact that the ore bodies are not in drinking-water-quality aquifers, ISR uranium operations have caused no adverse impact to underground sources of drinking water in the United States.

Contact Mark Pelizza at [email protected].

several hundred years. This isn’t good news as far as restoring geochemical conditions to premining conditions, but it provides assurance that contaminated groundwater will not migrate and contaminate new areas.

Future OperationsThe Grants uranium district still contains several hundred million pounds of uranium, now worth $60 per pound of U3O8. This elevated price will only raise interest in renewed mining and milling in the area. Conventional, open pit, and stope leach mining have historically been conducted in the Grants uranium district; all these methods, along with in-situ leaching, may be proposed in the future.

Environmental regulations that were absent during most of the past mining activities are now in place, along with more stringent mining regulations that will protect human health and the environment to a much greater degree. If water produced during new dewatering activities will be discharged to the surface, it will have to be treated to groundwater and possibly drinking-water standards prior to discharge. This will help prevent additional contamination, but water discharged to the surface could remobilize any contamination still present in the soil from the previous operational period if not addressed before new operations begin. This and continued exposure and oxidation of the ore body above the water table will continue to present challenges in managing potential contamination. However, the current regulations include flexibility to require protective engineering controls during operations and adequate financial assurance to address closure requirements.

Contact Jerry Schoeppner at [email protected].

ReferencesMcLemore, V.T., 2002. Database of Uranium Mines,

Prospects, Occurrences, and Mills in New Mexico, New Mexico Bur. Geology and Mineral Resources, Open-file Report 461, 11 pp.

McLemore, V.T., 2007. Uranium resources in New Mexico, Society for Mining, Metallurgy, and Exploration 2007 Annual Meeting, SME preprint 07-111.

World Health Organization, 2004. Guidelines for Drinking-water Quality: Summary Statement, 3rd ed., Geneva, WHO.

Solution-collapse breccia pipe uranium deposits occur in the CPUP, particularly in the Grand Canyon region.

The surface disturbance that results from mining this type of deposit historically has been remarkably small because of the high-grade, compact nature of the mineralization and use of underground waste rock backfill techniques during mine development. A 1,000- to 1,600-foot-deep shaft is usually required to access the deposits unless the pipe occurs near a deep canyon.

Breccia pipe ore grades are at least as high as any other global uranium-deposit type, at 0.4 to 1 percent, because the limited size of the pipe concentrates the uranium. Average ore reserves for an individual mineralized pipe are about 3.5 million pounds U308, with an average grade of about 0.6 percent uranium.

Volcanic uranium deposits are found in volcanic and volcaniclastic rocks. Volcanic deposits and hydrothermal veins occur in rhyolitic flows and tuffaceous ash flows, formed by hydrothermal, hot springs, or meteoric waters. Tabular lacustrine sandstone deposits occur in carbonaceous tuffaceous sandstone and mudstones, deposited by cooler groundwaters.

Several major uranium deposits in the RMIBUP occur as veins in metamorphic and sedimentary rocks, primarily within the Front Range and central Rocky Mountains of Colorado. Here, hydrothermal fluids directly deposited the uranium in fracture systems. Most of the BRUP deposits are volcanic, occurring as vein deposits and tabular ore bodies in paleolake sediments associated with volcanic activity. Volcanic deposits generally are developed by conventional mining methods.

Contact Clyde Yancey at [email protected].

ReferenceFinch, W.I., 1996. Uranium Provinces of North

America, Their Definition, Distribution, and Models, U.S. Geological Survey Bulletin 2141, U.S. Department of the Interior.

Geology, continued from page 21 In Situ, continued from page 29Remediation, continued from page 23

Water quality data from 89 baseline wells, collected prior to initiation of ISR operations, in the mineralized portion of the Oakville aquifer at the URI Inc. Vasquez ISR project in Duval County, Texas. EPA’s maximum contaminant levels (MCLs) are shown for comparison.

Parameter Average EPA MCL

uranium (ppb) 488 30

226radium (pCi/l) 215 5.0

222radon (pCi/l) 207,133 300

gross alpha (pCi/l) 865 15


(at three sites) or natural flushing (seven sites) was the selected compliance strategy, and remediation is ongoing.

Active groundwater remediation has generally been conducted at most Title II sites, though specific remedies vary. For many of the completed sites, remediation has not achieved background levels or maximum concentration limits and applications have been submitted to NRC for alternate concentration limits. NRC must approve cleanup of Title II sites, including groundwater, before the license is terminated and the site transferred to DOE for long-term custody. Ongoing groundwater monitoring is generally required at these sites along with annual site inspections. In addition to the five Title II sites that have transferred to DOE, several are in transition, with target transfer dates ranging from several months to many years away.

Monitoring ContinuesDOE regularly monitors groundwater at completed Title I and Title II sites to verify that constituent concentrations remain below alternate concentration limits and evaluate progress toward site cleanup goals where active remediation and natural flushing are employed. This evaluation is largely based on observing trends in site-related constituents such as uranium and nitrate. Immediately following the selection of a groundwater compliance strategy, groundwater sampling typically occurs quarterly to semiannually; sampling is decreased to annually or every five years once baseline data or trends are established.

Annual inspections of disposal cells are required. The cells seem to be performing as expected: minor seepage over the very long-term design life (1,000 years) has been recognized as unavoidable, but effects are confined to the immediate vicinity of disposal areas and are not expected to adversely affect water resources outside site boundaries. Established long-term-monitoring plans provide criteria that trigger certain actions if disposal cells require maintenance.

Continued monitoring of groundwater at most UMTRA Ground Water Project

sites still under remediation indicates that contaminant concentration levels are either remaining relatively constant or gradually decreasing. At some sites, residual contamination in the subsurface appears to provide an ongoing source of dissolved constituents. Trend analyses at several sites indicate that it may take multiple decades before all residual contamination is removed. Because natural flushing sites have 100 years to achieve compliance, assessing performance

based on a relatively short monitoring record is a challenge, particularly given the uncertainty associated with subsurface flow and transport.

Contact Judy Miller at [email protected] for more information.

ReferenceDOE, 1996. Final Programmatic Environmental Impact

Statement for the Uranium Mill Tailings Remedial Action Ground Water Project, DOE/EIS-0198, September. www.lm.doe.gov/documents/3_pro_doc/guidance/gw/peis/umtraTOC.htm

DOE, continued from page 27

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R & DPlutonium Clusters Offer Insight

Plutonium contamination in groundwater might become easier to model and remediate thanks to a breakthrough discovery at Argonne National Laboratory.

Plutonium tends to spread further than models predict, contaminating more groundwater and increasing the possibility of sickness in both humans and animals. These models have been based on single plutonium ions with a positive charge, which do not spread very far in groundwater because they are attracted to negative charges in substances such as plants and minerals.

However, plutonium can actually form into nanometer-sized clusters of plutonium oxide that behave very differently from single ions. Scientists at Argonne National Laboratory and the University of Notre Dame used high-energy X-rays to isolate the nanoclusters from groundwater and study their structure.

It turns out the nanoclusters consist of 38 plutonium atoms and have no charge. Because of this, their progression in groundwater is not slowed by attraction to other substances, allowing contamination to spread without inhibition.

This discovery will allow models to better account for the extent of plutonium contamination. In addition, scientists can direct their focus on how to break up the nanoclusters to improve the groundwater remediation process.

The properties of a few clusters with different numbers of plutonium atoms will also be the subject of more research.

Visit www.anl.gov.

Peripheral Canal Gains Support

Building a peripheral canal to carry water around the Sacramento-San Joaquin Delta is the most promising strategy to solve the ongoing debate about how to save the delta ecosystem while

still supplying water for California’s residents, concluded a July report by the Public Policy Institute of California.

Under current policy, water is drawn from the Sacramento River and sent south through the delta to enormous pumps that deliver water to millions of households in the Bay Area and Southern California as well as millions of acres of Central Valley farmland. This approach has threatened native fish and made the delta attractive to invasive species. Projected sea level rise, dilapidated levees, larger floods, and high earthquake potential threaten to dramatically change the delta environment, the report says.

Although the best strategy for fish populations would be for California to stop using the delta as a water source altogether, this would be extremely costly. A peripheral canal is the least expensive option and can be coupled with investment in the delta ecosystem. The report recommends allowing some delta islands to flood permanently for aquatic habitat while protecting high-value land, transitioning to a new management system as soon as possible, and developing a new framework with the proper safeguards for governing and regulating the delta.

California Department of Water Resources Director Lester Snow responded to the report, saying it “underscores the need for a long-term solution to fixing our water crisis in the delta.”

Visit www.ppic.org/main/pressrelease.asp?p=859 and www.water.ca.gov/news/newsreleases/2008/071708responseppic.doc.

Is Carbon-Capture the New Delta Crop?

California scientists envision a future for the Sacramento-San Joaquin River Delta based on carbon-capture farming, a process developed to sequester carbon, reverse subsidence, and create economic benefits. The California Department of Water Resources (DWR) has awarded the U.S. Geological Survey and the

University of California, Davis a three-year, $12.3 million research grant to study carbon-capture farming at a large scale.

Long-standing farming practices in the delta expose fragile peat soils to wind, rain, and cultivation; emit carbon dioxide; and cause land subsidence. Most of the farmed delta islands are more than 20 feet below the surrounding waterways and are permanently protected by levees. Water flowing through the delta’s levee system provides fresh water to millions of people and millions of acres of farmland, but continuing subsidence threatens the system.

Carbon-capture farming involves growing wetlands-type plants such as tules (a type of sedge) and cattails that remove carbon dioxide from the air. As the plants die and decompose, they create new peat soil, building the land surface over time. This could ease pressure on the levees and provide economic potential through developing carbon markets.

USGS and DWR have already partnered on a carbon-capture farming pilot project on deeply subsided Twitchell Island in the western delta. USGS scientists recorded elevation gains of more than 10 inches from 1997 to 2005 on two seven-acre test plots. Additional scientific work is necessary to learn how to maximize growth rates, verify greenhouse gas benefits over several years, and minimize any potential adverse environmental impacts. Construction of an expanded wetlands covering 400 acres on Twitchell Island is scheduled to start in spring 2009.

Visit ca.water.usgs.gov/news/ReleaseJuly23_2008.html.

Woody Plants Dissociated From Streamflow Decline

For the first time, researchers have demonstrated a hydrologic response to degradation and recovery of rangeland at a watershed scale. Texas A&M University and Texas AgriLIFE researchers reported in the July 2008 issue of Global Change


Biology that streamflow declines in the Concho River watershed in Texas result from rangeland recovery, not interception of would-be baseflow by woody plants as commonly thought.

The Concho rangeland began as prairie savanna, but heavy grazing from the 1870s to the 1950s transformed it to degraded grassland encroached by woody plants. Since 1960, vegetative cover―both woody and herbaceous―has increased. The researchers found that stormflows from 1960 to 2005 in the Concho watershed decreased significantly, particularly in the North Concho watershed, without any corresponding decrease in precipitation. In contrast, baseflow for all the watersheds remained essentially consistent or increased slightly in the same time period.

The authors concluded that higher levels of evapotranspiration from woody plants are not causing the drop in stormflow, because that effect would be reflected by a significant drop in baseflow as well. They attribute the stormflow decline to increased soil infiltration due to greater vegetation cover that slows overland flow.

The researchers believe that in contrast to the common belief that woody plants contribute to hydrological degradation, they have actually been part of the recovery process. Accordingly, they suggest that large-scale shrub clearing will not lead to significant increases in streamflow in many semi-arid rangelands.

See Wilcox, B.P., Y. Huang, and J.W. Walker, 2008. Long-term trends in streamflow from semiarid rangelands: Uncovering drivers of change, Global Change Biology, 14: 1676–1689, doi: 10.1111/j.1365-2486.2008.01578.x

Dams Favor Non-Native Fish, Hurt Natives

Damming of the Colorado River and introduction of game fish species has caused an extensive decline in native fish numbers, researchers reported in Science Daily in July. Physical changes to the river impair survival of native fish, but not introduced fish, because of their differing life histories.

Alice Gibb of Northern Arizona University and her colleagues studied the early life of both native and non-native fish species in the laboratory. Native fish are less

developed when they hatch compared to non-native fish, and as a result of the lack of adult swimming appendages, they have a poorer escape response to predators. Native species on the Colorado include razorback sucker, humpback and roundtail chub, bonytail chub, and pikeminnow.

Before the development of dams on the river, the native larvae were much better equipped for survival. Suspended sediment provided refuge from predators, turbulence made encountering plankton fairly easy, and warmer water allowed rapid growth. Dams have taken away these favorable conditions, replacing them with still, cold-water lakes.

Gibb suggested removing not only introduced predators, but the dams themselves to recreate the “high-flow, sediment-rich, warm waters that gave the Colorado its name,” she reported to Science Daily. She adds that recent research in Texas and the Pacific Northwest indicates that sediment might favor native fish in those areas as well.

See River Damming Leads to Dramatic Decline in Native Fish Numbers, www.sciencedaily.com /releases/2008/07/080709204836.htm.

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ClassifiedsLocation: Phoenix—Senior Hydrogeologist/Freeport-McMoRan Copper & Gold Freeport-McMoRan Copper & Gold Inc. (FCX) is a leading international mining company with headquarters in Phoenix, Arizona. The FCX Land & Water Department, which provides hydrogeologic services to Freeport sites worldwide, currently has two openings for Senior Hydrogeologists. The positions will provide project management services for various types of water resource development and water rights projects at operations worldwide. To view a detailed job description, visit the FCX website at http://www.fcx.com/careers/professional.htm; Job Number 0800891.


EducationTeens Jump into Arizona Rivers

Martha P.L. Whitaker, Jim Washburne and John Madden – University of Arizona

Some high school students spend their summers working part-time jobs or hanging out at the mall. But for 18 days in June, a group of high school students conducted environmental research at 15 riparian ecosystems throughout Arizona. The Arizona Rivers Project hosted this program, known as the high school Riparian Research Experience (RRE), to raise awareness and foster an appreciation of Arizona’s fragile riparian ecosystems. In addition, RRE aims to promote student-directed riparian research and develop lasting partnerships among students, teachers, and local riparian experts.

The program began with a three-day workshop at Biosphere 2, near Oracle, Arizona, where students and teachers worked together to learn methods of environmental data collection, including

water quality testing, sampling of macroinvertebrates (aquatic insects and arthropods) to assess river health, identification and census methods for birds and plants, and global positioning system skills to locate their data collection sites. The teachers completed the workshop with plans to implement their new knowledge in the classroom in the forthcoming year, while the students stayed on to begin their research tour of 15 riparian ecosystems in Arizona (see map).

The experience provided a unique opportunity for high school students to gain firsthand familiarity with a diversity of riparian ecosystems, develop skills to monitor riparian health, gain access to monitoring equipment and local experts, and conduct basic data collection and research—all within 18 days! The students plan to develop their own riparian research projects in the forthcoming academic year.

Arizona Rivers RRE was supported during its first year by Science Foundation Arizona, however, no long-term funding has been identified. Requests are already coming in from students and teachers to attend the next RRE, which is planned for summer 2009.

Visit www.azrivers.org.

Help send a kid to Riparian

Research Camp!

You can become a sponsor of the

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RRE students Jenny Miller and Myron Wolverton collect water samples at Wet Beaver Creek.

!!

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Flagstaff

Sedona

Prescott

Phoenix

Upper San Pedro

Cienega Creek

Catalina S.P.Biosphere 2

Middle San PedroAraviapa Creek

Roper Lake

San Fran. RiverGila Box

Tonto Creek Tonto Bridge

Stillman Lake

Wet Beaver CreekMontezuma’s Wall

Deadhorse S.P.

!!

Tucson

REE visited 15 riparian systems in Arizona.


In Print & OnlineManaging Ecosystems During Climate Change

Preliminary Review of Adaptation Options for Climate-Sensitive Ecosystems and Resources

U.S. EPA

This report aims to help mitigate the impacts of climate change on estuaries, forests, wetlands, and other sensitive ecosystems by identifying strategies to protect the environment as these changes occur.

Scientists reviewed established management goals for national parks, forests, wildlife refuges, wild and scenic rivers, estuaries, and marine protected areas to understand what strategies will increase the ability of each ecosystem to absorb change or disturbance before it shifts to a different ecosystem.

The report finds that many existing best management practices to reduce traditional stressors such as pollution or habitat destruction also can be applied to reduce the impacts of climate change.

The 910-page, peer-reviewed report is available at cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=180143.

Controlling Contaminants in Drinking Water

Drinking Water Treatability Database

U.S. EPA

EPA’s Drinking Water Treatability Database (TDB) presents referenced information from thousands of sources on controlling drinking water contaminants. It can be searched by type of contaminant or treatment process. Literature included in the database covers bench-, pilot-, and full-scale studies of surface waters, groundwaters, and laboratory waters. New contaminants and updates on existing contaminants will be added continually; ultimately, it will include over 250 regulated and unregulated contaminants and 30 treatment processes.

The database is available at iaspub.epa.gov/tdb/pages/general/home.do.

Trees Offer Clues to Subsurface Contamination

User’s Guide to the Collection and Analysis of Tree Cores to Assess the Distribution of Subsurface Volatile Organic Compounds

U.S. Geological Survey

Analysis of the volatile organic compound (VOC) content of tree cores

is an inexpensive, rapid, and simple approach to examining the distribution of subsurface VOC contaminants, according to this report. The method has been shown to detect several volatile petroleum hydrocarbons and chlorinated aliphatic compounds associated with

continued on next page

2009 Annual Water Symposium

MANAGING HYDROLOGIC EXTREMES

Arizona Hydrological Society

American Institute of Hydrology

August 30-September 2, 2009 Westin Kierland Resort & Spa

Scottsdale, Arizona www.hydrosymposium.org

Symposium sponsored by:

Jointly hosted by:


In Print & Online (continued)

vapor intrusion and groundwater contamination. Three-inch-long tree cores are analyzed by headspace analysis gas chromatography. Because the roots are exposed to VOC contamination in the unsaturated zone or shallow groundwater, VOC concentrations in the tree cores indicate the presence of subsurface VOC contamination and can be used to map it.

The 72-page report is available at pubs.usgs.gov/sir/2008/5088/.

Understanding Climate Change Impacts on Border Water

Water and Border Area Climate Change

California Department of Water Resources

Prepared for the XXVI Border Governors Conference, this report provides an introduction to climate change in the U.S.-Mexico border region from the water sector perspective. Using numerous charts, maps, and other graphics, the report focuses on likely impacts of

climate change on the region’s water resources and identifies areas where more research is needed. It concludes with recommendations for climate adaptation strategies for the water sector, with consideration of the challenges of working across an international border.

The 68-page report is available at www.water.ca.gov/news/newsreleases/2008/081508bgcreport.pdf.

Practical Guide to Water Resources

Watersheds, Groundwater and Drinking Water

Agriculture and Natural Resources Division, University of California

This book aims to help resource managers, planners, and other decision makers better understand and assess water supplies and define and manage protection areas for water sources.

The first section covers fundamentals such as watershed hydrology,

groundwater hydrology, water quality, and water contamination. Part 2 describes tools and background information that can help assess and protect individual water sources, such as sampling and monitoring, delineating watersheds and groundwater recharge areas, and determining possible contaminating activities.

Although written with the water needs of Californians in mind, much of the basic information is applicable to other western states.

The 274-page book is available for $40 at anrcatalog.ucdavis.edu/Items/3497.aspx.

Water-Sector Corruption Is Cause for Concern

Global Corruption Report 2008

Transparency International

This report sets forth the argument that corruption is a cause and catalyst for the current global water crisis, in which more than one billion people have inadequate access to safe drinking water. Furthermore, it argues that the crisis will likely be exacerbated by climate change.

The report documents how corruption affects all aspects of the water sector, from water resources management to drinking water services, irrigation, and hydropower, with case studies from around the world and suggestions for reform. In the Southwest, San Diego was used as an example of corruption for political power, as “an audit in 2006 found that households were improperly overcharged on their monthly sewage bills, with the excess being unlawfully used to subsidise the sewage costs of large industrial users.”

The report details corruption-related developments in 35 countries and presents summaries of corruption-related research, highlighting methodologies and new findings that may improve understanding of the dynamics of corruption and assist in devising more effective anti-corruption strategies. 262.542.5733 • www.aquiferscience.com

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Transparency International is a 15-year-old, Berlin-based, nonprofit organization.

Access the 345-page report at www.transparency.org/publications/gcr/.

DVD Promotes Water Reuse

Water Reuse for a Sustainable Future

American Water Works Association

One way to meet increasing water demand is through water reuse, in which wastewater is treated for use in irrigation, toilet flushing, and other nonpotable uses. This DVD is designed for water providers who want to inform communities, water boards, mayors, governors, and others about the positive potential of reuse for creating a more sustainable environment for their users. Viewers learn about the hydrologic cycle, treatment cost savings associated with reuse, and the environmental benefits of water reuse. The 11-minute DVD provides examples of water reuse projects in California.

The DVD costs $195 for AWWA members, $295 for nonmembers and is available at www.awwa.org/Bookstore/productDetail.cfm?ItemNumber=34914.

Developing Watershed Plans: the Details

Handbook for Developing Watershed Plans to Restore and Protect Our Waters

U.S. EPA

EPA’s Office of Wetlands, Oceans, and Watersheds recently released this 400-page document to help communities, watershed organizations, and environmental agencies at all levels develop and implement watershed plans to meet water quality standards and protect water resources. Targeted particularly to those working with impaired or threatened waters, the document contains detailed guidance on quantifying existing pollutant loads, developing estimates of the load reductions required to meet water quality standards, developing effective management measures, and tracking progress once a plan is implemented. It also offers ways to protect important

elements of the landscape and aquatic habitats within a watershed.

The handbook document is available at www.epa.gov/owow/nps/watershed_handbook/.

New Water Quality Website

ATTAINS

U.S. EPA

EPA has released a new database/website for water quality assessment and total maximum daily load (TMDL) information. The site, known as ATTAINS, combines two formerly separate databases: the National Assessment Database (for water quality assessment information reported by states), and the National TMDLs Tracking System (for impaired waters information reported by states).

The site includes state-reported information on: support of designated uses; identified causes and sources of impairment; identified impaired waters; and status of actions to restore impaired

waters. It allows the user to view dynamic tables and charts that summarize state-reported information for the nation as a whole, for individual states and waters, and for the 10 EPA regions.

The website is at www.epa.gov/waters/ir.

Real-Time WQ Info Online

WaterQualityWatch

U.S. Geological Survey

Real-time water-quality data are now accessible online through the USGS WaterQualityWatch website. Measurements are available at more than 1,300 sites across the United States in streams with watersheds as small as a few square miles to more than a million square miles in the Mississippi River. Measurements include streamflow, water temperature, specific conductance, pH, dissolved oxygen, and turbidity.

Access the website at water.usgs.gov/waterwatch/wqwatch.

Dissolved solids in basin-fill aquifers and streams in the southwestern United States—Executive Summary, by D.W. Anninghttp://pubs.usgs.gov/fs/2008/3076

Ground-water storage change and land subsidence in Tucson Basin and Avra Valley, southeastern Arizona, 1998-2002, by D.R. Pool and M.T. Andersonhttp://pubs.usgs.gov/sir/2007/5275/

Hydrologic data from the study of acidic contamination in the Miami Wash-Pinal Creek Area, Arizona, water years 1997-2004, by A.D. Konieczki, J.G. Brown, and J.T.C. Parkerhttp://pubs.usgs.gov/of/2008/1273/

Traveltime for the Truckee River between Tahoe City, California, and Vista, Nevada, 2006 and 2007, by E. James Cromptonhttp://pubs.usgs.gov/of/2008/1084/

Evaluation of the acoustic doppler velocity meter for computation of discharge records at three sites in Colorado, 2004-2005, by M.R. Stevens, Paul Diaz, and D.E. Smitshttp://pubs.usgs.gov/sir/2007/5236/

Comparison of water years 2004-05 and historical water-quality data, Upper Gunnison River Basin, Colorado, by N.E. Spahr, D.M. Hartle, and Paul Diazhttp://pubs.usgs.gov/ds/331/


T H E C A L E N D A R

November 3-4 Nielsen Environmental Field School. Surface Water and Sediment Sampling Field Course. Las Cruces, NM.

www.envirofieldschool.com/course.htm

November 3-5 National Ground Water Association. Petroleum Hydrocarbons Conference (Nov. 3-4), Approaches to Predicting NAPL Behavior (short course, Nov. 5), Evaluating Ground Water Flow and Transport Modeling: Guidelines for Hydrogeologists Who Don’t Model

(short course, Nov. 5). Houston, TX. www.ngwa.org/development/calendar.aspx

November 12-13 Water Education Foundation. San Joaquin River Restoration Tour. Fresno, CA area. www.watereducation.org/toursdetail.asp?id=845

November 16-18 WateReuse Association. Potable Reuse for Water Supply Sustainability. Long Beach, CA. www.watereuse.org/conferences/potable-reuse

November 17-20 American Water Resources Association. 2008 AWRA Annual Water Resources Conference. New Orleans, LA.

www.awra.org/meetings/NewOrleans2008

November 18-20 Water Education Foundation, federal agencies, and others. Colorado River Basin Science and Resource Management Symposium.

Scottsdale, AZ. www.watereducation.org/doc.asp?id=1072

November 19-20 Groundwater Resources Association of California. Emerging Contaminants 2008. San Jose, CA. www.grac.org/contaminants.asp

December 1-3 National Ground Water Association. Intro to Ground Water Geochemistry and Reaction Modeling (Dec. 1), Artificial Recharge of Ground Water (Dec. 1-2), Springs Ecosystem Inventory, Monitoring, and Assessment (Dec. 1-3) (short courses). Las Vegas, NV.

www.ngwa.org/development/shortcourses.aspx

December 2-3 Northwest Environmental Training Center. Monitored Natural Attenuation of Petroleum and Chlorinated Hydrocarbons in Soil and

Groundwater. Phoenix, AZ. www.nwetc.org/ghyd-410_12-08_phoenix.htm

December 2-5 National Ground Water Association. NGWA Ground Water Expo and Annual Meeting. Las Vegas, NV.

www.ngwa.org/development/conferences/2008GroundWaterExpoAnnualMeeting6010.aspx

December 15-17 Colorado River Water Users Association. 2008 Annual Conference: Power of Water. Las Vegas, NV. www.crwua.org

December 15-19 American Geophysical Union. AGU Fall Meeting. San Francisco, CA. www.agu.org/meetings/fm08/

January 15-16 Multi-State Salinity Coalition and Bureau of Reclamation. 9th Annual National Salinity Summit - Water and Energy: Our Future in

Balance. Las Vegas, NV. wrri.nmsu.edu/conf/NSS.pdf

January 22-23 University of Arizona College of Law. Adaptation to Climate Change in the Desert Southwest. Tucson, AZ.

www.law.arizona.edu/news/faculty/ualawevents.cfm

February 3-5 Nevada Water Resources Association. Annual Conference. Reno, NV. www.nvwra.org

February 12-13 American Water Works Association. Research Symposium: Emerging Organic Contaminants. Austin, TX. www.awwa.org

February 25-26 Groundwater Resources Association of California. Groundwater Monitoring Conference. Anaheim, CA. www.grac.org/monitoring.asp

March 2-6 Princeton Groundwater Inc. Groundwater Pollution and Hydrology Course. San Francisco, CA.

princeton-groundwater.com/pollution-and-hydrology-course.htm

March 16-22 World Water Council. 5th World Water Forum: Bridging Divides for Water. Istanbul, Turkey. www.worldwaterforum5.org/

March 29 Environmental and Engineering Geophysical Society. SAGEEP 2009: Expanding Horizons for Near-Surface Geophysics. Fort Worth, TX.

www.eegs.org/sageep/index.html

March 30-April 2 Forester Media Inc. WaterEC: International Water Efficiency Conference. Newport Beach, CA. waterec.net/wec.html

April 6-9 New Mexico Rural Water Association. Annual Conference. Albuquerque, NM. www.nmrwa.org/2009conference.php

April 19-23 National Ground Water Association. 5th Annual NGWA Ground Water Summit—The Science Conference: Adapting to Increasing

Demands in a Changing Climate. Tucson, AZ. www.ngwa.org/2009summit/

April 27- May 1 Princeton Groundwater Inc. Remediation Course. Las Vegas, NV. princeton-groundwater.com/remediation-course.htm

NOVEMBER 2008

DECEMBER 2008

JANUARY 2009

FEBRUARY 2009

MARCH 2009

APRIL 2009


T h e R e s o u r c e f o r S e m i - A r i d H y d r o l o g y We thank our advertisers for their support:

P.O. Box 210158B, Tucson, AZ 85721-0158 · visit our web site: www.swhydro.arizona.edu · 520.626.1805

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