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The University of Arizona’s Water Resources Research Center provides research grants through Section 104(b) of the Water Resources Research Act. Funded by the U.S. Geological Survey, the Section 104(b) program supports small water related projects of importance to the state and the region. These projects seek to increase our understanding of scientific phenomena, educate students, and foster the entry of new scientists in water research. Faculty at all three Arizona state universities are eligible for 104(b) funding. The WRRC awarded grants for five projects in 2010.
Perfluouronated Compounds in Arizona Groundwater: Sources of Contamination.
In 2009 the Tucson Water Department detected a trace organic contaminant called perfluorooctane sulfonate at minute levels in four wells, and in the finished Central Arizona Project water produced by the Clearwater Recharge and Recovery Facility. The origin of PFOS contamination in the Tucson region is unknown. Effluent infiltrating into the local aquifer from the Santa Cruz River is one potential source. Recharged CAP water and stormwater runoff may also contribute.
University of Arizona researchers David M. Quanrud, Leif M. Abrell, Robert G. Arnold and A. Eduardo Sáez intend to identify major sources of PFOS in Tucson’s groundwater and determine if a related compound, perfluorooctanoic acid, is also present. The investigators will collect data at critical locations in Tucson and Marana, and study the contaminants’ fates at a CAP recharge facility and the Sweetwater Recharge Facilities. This project is an initial step toward developing a management strategy for PFOS contamination in Tucson’s groundwater.
Bioremediation of Uranium Plumes with Nano Scale Zero Valent Iron.
Levels of uranium exceeding EPA standards have been found in Arizona wells, including the Sierrita mine site near Green Valley. A potential carcinogen and endocrine disrupter, uranium leaches into water from mine tailings, former processing plants, and natural background levels in granite bedrock.
UA researchers James A. Field and Reyes Sierra are developing a low cost, onsite bioremediation method with microorganisms that use zero valent iron as a substrate. Previous research has shown that ZVI can chemically reduce uranium to an insoluble form. The investigators hypothesize that ZVI provides a buffer against reoxidation, and that microorganisms will enhance the reaction. They will prepare a controlled experiment to evaluate the potential of this form of treatment. This research will help develop cost effective treatment systems for uranium and other oxidized pollutants in drinking water, addressing a critical global need.
Use of Fish as Integrative Samplers of Uranium and Lead Isotopes in the Colorado River.
Uranium contamination is also a concern in the Colorado River. UA investigators Charles A. Sanchez, John T. Chesley, and Peter N. Reinthal intend to identify the sources and sinks of uranium, lead and other metal contaminants in the Colorado River by using fish tissue as integrative sampler for the contaminants of interest. They will compare the new data with historical fish samples at the UA and Arizona State University from the past 100 years. The project will help determine potential sources and pathways of contamination in the food web of the Colorado River Basin, a necessary step for designing management strategies. The data will also provide a baseline in case future mining activity alters contaminant levels.
Nitrogen is another groundwater contaminant of concern in this region. Recent research has suggested that atmospheric deposition, in aerosols or precipitation, may be a significant contributor to water contamination, especially as fossil fuel use has increased. UA researchers Jennifer C. McIntosh, Armin Sorooshian, and Kathleen Ann Lohse seek to determine the sources and amounts of nitrogen deposited in a sky island ecosystem, and how it is transported to groundwater. The investigators will collect samples from soil pore water, surface waters, and atmospheric deposition at three sites that span the full elevation gradient of the Santa Catalina Mountains. The sites provide a range of climates and bedrock types to compare. This project contributes to ongoing studies of how the hydrology of mountain systems surrounding urban areas impacts groundwater quality.
Biochar Soil Amendments to Increase the Water Holding Capacity of Sandy, Arid Soils.
Another project, led by UA researchers Janick F. Artiola, Craig Rasmussen and Robert J. Freitas, will investigate how biochar amendments affect the physical properties of Arizona soils. As Arizona enters a second decade of statewide drought, water conservation is increasingly important — particularly in agriculture, which accounts for 70 percent of the state’s water use. Yet Arizona’s sandy soils do not retain water efficiently and thus require more frequent irrigation. Biochar, a carbon based porous charcoal, acts as a long lasting sponge in soils. The investigators will determine how various biochar amendments alter the soil moisture, surface albedo and soil temperature over time. By increasing the soil’s water holding capacity, the investigators expect biochar amendments will improve irrigation efficiency, plant growth and soil fertility.
Each project will be funded for one year, beginning in March 2010. Contact the investigators for details about their work. For more information about the Section 104(b) grant program, or how to apply for a grant, go to http://ag.arizona.edu/azwater/programs/104.