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2013 USGS 104b Program Grants


Project Number: 2013TN104B, 2014
Title: Re-filling the Bucket: Recharge Processes for the Memphis Aquifer in the Exposure Belt in Western Tennessee
Team: Dan Larsen, Scott Schoefernacker, and Brian Waldron, University of Memphis

Little is currently known regarding direct recharge to the Memphis aquifer across the unconfined region in western Tennessee; however, initial investigations indicate that little recharge may penetrate through the upland surfaces, taking possibly 100 years to move from the ground surface down to the water table. Gaining an understanding of recharge processes in the unconfined region of the aquifer is critical to understanding input rates both spatially and temporally so as to ascertain the impact of land use and climate change and ultimately effect the long-term sustainability of this valuable and heavily relied upon natural resource. The proposed project will investigate recharge processes in the unconfined region of the Memphis aquifer at the Pinecrest site, near LaGrange, Tennessee. Initial investigations have included using vadose-zone and saturated zone chloride mass balance methods (CMB) to estimate recharge in the upland region (i.e. thick vadose zone), installation of and continuous water level monitoring in an observation well on an upland surface screened within the Memphis aquifer, and recurrent analyses of vadose zone soil moisture profiles within one of the wells using a neutron probe. Furthermore, geologic mapping and reconnaissance soil studies have clarified geologic and soil control on recharge process.

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Project Number: 2013TN101B, 2013
Title: Chemical and Morphological Analyses of Trout Otoliths as a Measure of Aluminum Exposure in Streams Impacted by Acid Deposition in the Great Smoky Mountains National Park
Team: Michelle Connolly and John Schwartz, UT Civil and Environmental Engineering

Acid deposition is a global issue, which greatly affects fish populations throughout the Northern Hemisphere. In the Southeastern United States stream acidification is thought to be responsible for the extirpation of brook trout (Salvelinus fontinalis) from many headwater streams in the Great Smoky Mountains National Park (GRSM). The management of fishery resources and particularly populations of native brook trout is a high priority for conservation efforts within the Park. Streams within the GRSM are particularly susceptible to the effects of acid deposition due to the low buffering capacity associated with the geology in this region. Our archival datasets indicate that aqueous aluminum (Al) is prevalent at high elevations in the Park, where acid deposition has led to increased trace metal exposure, especially under stormflow conditions. Yet until recently it was unclear whether these Al levels were bio-accumulating in fish. In 2011, members of our research team were the first to show that trace aluminum could be detected in GRSM fish (rainbow trout otoliths and gill arches). Otoliths have long been used as an environmental archive as they continuously incorporate inorganic material (including trace metals) into their calcified matrix. However, relatively little is known about aluminum (Al) uptake in freshwater fish, especially among streams impacted by acid deposition. Notably, our 2011 study was conducted within Walker Camp Prong (WCP), a GRSM stream that is impacted by acid deposition but is also buffered by unusual calcium (Ca) levels due to the salting of nearby roads. Here we propose extending our research efforts to four GRSM streams that are not buffered by anthropogenic Ca input, in order to determine whether the age-specific Al/Ca trends observed among fish from Walker Camp Prong are applicable to other regions and species (brook trout) in the Park. As our research team has previously shown that an abnormal form of calcium carbonate calcification is present in a subset of fish in the Park, trout otoliths will be excised and photographed prior to trace metal analysis in order to map differences in bone morphology (vateritic otolith formation) within and across sites. This morphological survey will contribute to our understanding of abnormal otolith formation in the Park and will help determine whether these morphological differences are linked to Al-rich environments. In addition, this work will provide insight into species-specific tolerance to acid deposition among brook trout and rainbow trout, which will help delineate the upper limit their range in acidic environments. Following morphological analyses, otoliths will be chemically analyzed. Trace Al and Ca levels will be quantified among sagittal otoliths using established Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) methods. These data will be compared to archival aqueous datasets (1993-present), which have been collected by Dr. Schwartz group (co-PI on this project) in order to develop predictive regression models of the biological impacts of acid deposition in the Park. These regression analyses will also be used to provide information on stream conditions where long-term chemical analysis data are not available and will thus contribute to ongoing management and prioritization strategies in the Park.

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Project Number: 2013TN100B, 2013
Title: Long-term Evaluation of Norris Dam Operation under Changing Environments
PI: Ungtae Kim, UT Institute for a Secure and Sustainable Environment and UT Civil and Environmental Engineering

This project aims to provide practical decision-making information for long-term water resources manage - ment in the TVA region based on demonstrated data sources and robust hydrologic methods. The uncertainty of the results generated in this project inherently relies on the credibility of current and future watershed information. This project therefore will emphasize the role of the operating guide currently used in the Norris reservoir to maintain the Clinch River keeping its designated performance. This study found that while the current operating guide will allow the Norris reservoir to meet various flood protection, navigation, and electrical power generation goals in the future, it may be possible to gain additional operating flexibility through modification of the operating guide to meet future conditions.

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Project Number: 2013TN99B, 2013
Title: Engineered Strategy to Remediate Trace Organic Contaminants Using Recirculating Packed-Bed Media Biofilters at Decentralized Wastewater Treatment Systems: Determination of Trace Organic Sorption to Treatment Media
Team: John R. Buchanan, Associate Professor, and Jennifer DeBruyn, Assistant Professor, UT Biosystems Engineering and Soil Science

This project will create new information as to the ability of recirculating packed-bed media biofilters to remove seven trace organic contaminants from domestic wastewater. Each day hundreds of chemicals, including hormones, antibiotics, surfactants, and other pharmaceuticals and personal care products (PPCPs) are used and subsequently released to the environment through domestic/municipal wastewater discharge. These organic wastewater contaminants (OWCs) have been widely detected in surface and groundwater resources, and in soils under the land application of municipal biosolids and septage. The ecological and environmental risks resulting from the release of OWCs are not fully understood.

A packed-bed media biofilter is a slow-rate, fixed-film (or attached-growth) unit process used for secondary and tertiary wastewater treatment. This process passes primary-treated effluent through a porous, inert media (the packed-bed) where waste constituents diffuse out of the bulk water and into the biofilms that form on the media. A recirculating packed-bed media biofilter (RPBMB) recirculates the effluent through the media several times for enhanced organic carbon removal and nitrification (oxidation of ammonia to nitrate). Four laboratory-scale RPBMB systems were constructed to determine the removal efficiencies of three target trace organic contaminants: triclosan—an endocrine disrupting compound, and ibuprofen and naproxen—two nonsteroidal anti-inflammatory drugs. Each system included a supply tank, a 51-cm tall by 10-cm diameter column filled with media (3-5 mm fine gravel), a recirculation tank, and a final product tank. Primary-treated wastewater from a community-scale decentralized treatment system served as the wastewater source. The supply tanks emulated the discharge from primary treatment (liquid/solid separation) and fed into the recirculation tank on a diurnal basis—representing the higher wastewater flows that occur during mornings and evenings. Effluent in the recirculation tank was then micro-dosed to the column five times per hour. Every fifth time the recirculation pump dosed the column, the three-way valve switched state, and the column effluent drained to the final discharge. Septic tank effluent from a near-by housing development was also used as the wastewater source, where subject compounds were present, for these secondary-treatment devices. The subject compounds were present in the source water. To gain more information about removal efficiencies, one system was spiked with triclosan, the second with naproxen, the third with ibuprofen, and the forth system was a non-spiked control. Overall, the laboratory-scale RPBMB removed 70% of the ibuprofen, 79% of the naproxen, and 82% of the triclosan. This preliminary data indicates that this decentralized wastewater treatment technology can potentially remove these three compounds with the same efficiency as larger municipal-scale systems. Further investigations are needed to determine whether the removal process is by microbial degradation or by sorption to the media.

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Project Number: 2012TN92B, 2013
Title: Determining Channel Protection Flows in Urban Watersheds Through Effective Strategies for Stormwater Management and Stream Restoration
PI: John Schwartz, UT Civil and Environmental Engineering

This project will create new information as to the ability of recirculating packed-bed media biofilters to remove seven trace organic contaminants from domestic wastewater. Each day hundreds of chemicals, including hormones, antibiotics, surfactants, and other pharma - ceuticals and personal care products (PPCPs) are used and subsequently released to the environment through domestic/municipal wastewater discharge. These organic wastewater contaminants (OWCs) have been widely detected in surface and groundwater resources, and in soils under the land application of municipal biosolids and septage. The ecological and environmental risks resulting from the release of OWCs are not fully understood. Recirculating packed-bed media biofilters (RPBMB) are a low-cost and low- maintenance wastewater treatment process that is well suited for individual onsite and very small community applications. Approximately 25% of the domestic wastewater generated in the US is processed by individ - ual onsite or very small wastewater treatment systems. Unlike municipal sewage treatment plants, these small systems generally depend on the soil for treatment and effluent dispersal. The specific objective of this project is to determine whether the combination of endogenous respiration and nitrate-reducing conditions found in a RPBMB can maximize the biodegradation of OWCs found in domestic wastewater. Using a series of laboratory-scale RPBMB, the removal of seven commonly found OWCs will be monitored. The OWCs will include triclosan, bisphenol-A, ibuprofen, diclofenac, naproxen, sulfa - methoxazole, and 17alpha-ethinyl estradiol.

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