Browsing by Author "Estepp, Lisa"

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    The MnDRIVE Transdisciplinary Project Implementation of Smart Bioremediation Technology to Reduce Sulfate Concentrations in NE Minnesota Watersheds
    (University of Minnesota Duluth, 2017-07-14) Hudak, George J; Estepp, Lisa; Schoff, Patrick K
    This report opens with an Executive Summary, which briefly describes the project’s major accomplishments to date. The body of the report is constructed in sections focused on five related project efforts: 1) Bioreactor Design, Operation, and Performance, 2) Power Management, 3) Microbiology, 4) Chemical Treatments, and 5) Economic Aspects of Sulfate Reduction. Each of these sections, in turn, starts with a brief summary, which is followed by a detailed report. Additional materials concerning bioreactor design, construction, and operation, as well as experimental design, rationale, methods, and data are included in appendices. In addition, the MnDRIVE Project Accountability metrics, which contain a breakdown of particular project tasks, are included as appendices.
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    Paleolimnology of the St. Louis River Estuary
    (University of Minnesota Duluth, 2016-05) Reavie, Euan D; Alexson, Elizabeth; Axler, Richard P; Yost, Chad; Ladwig, Jammi; Nurse, Andrea; Estepp, Lisa; Krasutsky, Pavel A; Kennedy, Kathleen; Yemets, Sergiy; Engstrom, Daniel R
    The St. Louis River Watershed which drains to the St. Louis River and its associated estuary near Lake Superior has more than 150 years of human development history since Euro‐Americans first settled there, resulting in critical water quality impacts. In 1987, the U.S. Environmental Protection Agency designated the St. Louis River as an Area of Concern primarily due to that history which entailed inappropriate discharge of untreated wastewater and debris from poor industrial and community practices. The organic matter loading from inadequate treatment of sewage and paper mill products along with the dumping of woody debris from sawmills contributed to low oxygen levels in the river. The result included devastating impacts to the entire food web from the bacteria to vegetation to invertebrates to fish. Concurrently, poorly managed stormwater runoff from this post‐logged, barren landscape contributed excessive loading of suspended sediments resulting in increased turbidity and nutrient concentrations (e.g., phosphorus, nitrogen) to the river. Since then, government and private entities have taken action to restore the water quality in the St. Louis River Estuary, and to eventually remove the eight remaining SLRAOC BUIs. This summary focuses on the research documenting water quality changes over time associated with the excessive loading of sediment and nutrients BUI.