Potomac Environmental Research and Education Center

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The mission of the Potomac Environmental Research and Education Center is to utilize the tools of scientific research, restoration, education, and policy analysis to help society understand and sustain natural processes in ecosystems, watersheds, and landscapes.

Research foci for the Center include:
  • Restoration of the Potomac River and its Tributaries
  • Sustainability of Natural Ecosystems in Suburban Areas
  • Impact of Global Climate Change on Management of Aquatic Ecosystems


Recent Submissions

Now showing 1 - 20 of 28
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    Microplastics in the Tidal Freshwater Potomac
    (2019) Rhoades, Benjamin; Nguyen, Han; Wigode, Evan; Sklarew, Daniel M.; Foster, Gregory D.
    Microplastics (MPs) are pieces of plastic between 0.33mm and 5mm and represent a near ubiquitous type of pollution and have been found in almost all bodies of water sampled. MPs represent both an ecological and a public health threat, as vectors of toxic chemicals. Only one peer-reviewed paper quantifies the microplastics issue in the Chesapeake Bay region, with no published findings regarding microplastics in tidal freshwater Potomac River. Yonkos et al. (2015) considers population density of a watersheds in the Bay region as a factor influencing MP concentrations. This study investigates MPs in the Potomac River basin and the impact of land development on MP concentrations.
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    An Ecological Study of Gunston Cove 2017
    (2018-12) Jones, R. Christian; Mutsert, Kim de; Fowler, Amy
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    Escherichia coli abundances in Hunting Creek/Cameron Run and adjacent Potomac River 2015
    (2016-12-04) Jonas, Robert
    During 2015, in connection with examination of ecological and chemical parameters, a study of Escherichia coli in waters in the areas of Hunting Creek/Cameron Run and adjacent waters of the Potomac River was continued with samples being collected at the same sites as in 2014. This work provides current microbiological water quality information in these aquatic ecosystems adjacent to and receiving water from the wastewater reclamation facility operated by Alexandria Renew Enterprises (Alex Renew). As previously one basic question is whether any of these waters are impaired under the Clean Water Act in terms of their designated uses.
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    Anadromous Fish Survey Cameron Run 2015
    (2016-12-04) de Mutsert, Kim
    The focus of the Cameron Run fish survey is river herring, the collective name of blueback herring and alewife. River herring populations have declined drastically over their range, spurring conservation efforts since 1970, which have been intensified since 2005 with implementation of moratoria. Identifying all areas used as spawning habitat by alewife and/or blueback herring is an important component of their conservation. Since 1988, George Mason University researchers have focused a monitoring program on the spawning of these species in other tributaries such as Pohick Creek, Accotink Creek, and, less regularly, Dogue Creek. With this study Cameron Run is added, which has not been monitored for presence of river herring or other anadromous species by either George Mason or other fisheries biologists before the start of this study in 2013 (Jim Cummins, pers. comm.). Our 2013 survey provided the first confirmation of Cameron Run as River Herring spawning habitat (Allan Weaver, VDGIF, pers. comm.). Use of Cameron Run by river herring upstream from where the effluent of Alexandria Renew Enterprises enters Cameron Run signifies that the effluent does not deter river herring from using Cameron Run as spawning habitat. In 2014 we moved the collection site approximately 500 m downstream (still above the Alexandria Renew Enterprises effluent), which increased our catches, and allows us to estimate the size of the spawning population. The new location proved successful and will remain the collection site for any subsequent surveys.
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    The Aquatic Monitoring Program for the Hunting Creek Area of the Tidal Freshwater Potomac River 2015
    (2016-12-04) Jones, R. Christian; de Mutsert, Kim
    This section reports the results of the third year of an aquatic monitoring program for Alexandria Renew Enterprises conducted by the Potomac Environmental Research and Education Center (PEREC) in the College of Science at George Mason University. Three other sections of the report include an anadromous fish study of Cameron Run, a study of the incidence of PCB’s and endocrine disrupting chemicals in Hunting Creek, and a survey of Escherichia coli levels in the Hunting Creek area of the tidal Potomac River. This work was in response to a request from Karen Pallansch, Chief Executive Officer of Alexandria Renew Enterprises (Alex Renew), operator of the wastewater reclamation and reuse facility (WRRF) which serves about 350,000 people in the City of Alexandria and the County of Fairfax in northern Virginia. The study is patterned on the long-running Gunston Cove Study which PEREC has been conducting in partnership with the County of Fairfax Department of Public Works and Environmental Services since 1984. The goal of these projects is to provide baseline and on-going trend analysis of the ecosystems receiving reclaimed water from wastewater treatment facilities with the objective of adaptive management of these valuable freshwater resources. This will facilitate the formulation of well-grounded management strategies for maintenance and improvement of water quality and biotic resources in the tidal Potomac. A secondary but important educational goal is to provide training for Mason graduate and undergraduate students in water quality and biological monitoring and assessment.
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    An Ecological Study of Hunting Creek 2015
    (2016-12-04) Jones, R. Christian; de Mutsert, Kim; Jonas, Robert; Huff, Thomas
    Hunting Creek is an embayment of the tidal Potomac River located just downstream of the City of Alexandria and the I-95/I-495 Woodrow Wilson bridge. This embayment receives treated wastewater from the Alexandria Renew Enterprises wastewater treatment plant and inflow from Cameron Run which drains most of the Cities of Alexandria and Falls Church and much of eastern Fairfax County. Hunting Creek is bordered on the north by the City of Alexandria and on the west and south by the George Washington Memorial Parkway and associated park land. Due to its tidal nature and shallowness, the embayment does not seasonally stratify vertically, and its water is flushed by rainstorms and may readily mix with the adjacent tidal Potomac River mainstem. Beginning in 2013 the Potomac Environmental Research and Education (PEREC) in collaboration with Alexandria Renew Enterprises (AlexRenew) initiated a program to monitor water quality and biological communities in the Hunting Creek area including stations in the embayment itself and the adjacent river mainstem. This document presents study findings from 2015 and compares them with 2013 and 2014 data. In addition special studies were conducted on anadromous fish usage of Hunting Creek and Cameron Run, Escherichia coli levels in Hunting Creek and tributaries, and micropollutant levels in sediments and waters of Hunting Creek and Cameron Run.
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    An Ecological Study of Hunting Creek 2013
    (2014-04-09) Jones, R. Christian; de Mutsert, Kim; Foster, Gregory D.
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    Diel and seasonal patterns in water quality continuously monitored at a fixed site on the tidal freshwater Potomac River
    (Freshwater Biological Association, 2013) Jones, R. Christian; Graziano, Alexander P.
    Recent advances in water quality monitoring have facilitated the acquisition of temporally rich datasets that allow comprehensive analysis of patterns and underlying processes and drivers at multiple scales. We analyzed data from a continuous water quality monitor on the tidal Occoquan River, a tributary of the tidal Potomac River and Chesapeake Bay. Temperature, conductivity, dissolved oxygen (DO), and pH were collected at 15 minute intervals from April through early November of 2010. Results of time series analysis indicate that, on a short-term basis, conductivity manifested an underlying semidiel pattern, presumably driven by tidal excursion. In comparison, DO, pH, and temperature exhibited a diel pattern correlated with the daily light and temperature cycle. Longer-term patterns were related to longer-term climatic factors such as a dry summer with low freshwater inputs, seasonal progressions of light and temperature, and a river discharge spike in early October. Examination of multiday patterns in DO and pH using 15 minute data during a climatically stable period illustrated both diel and semidiel patterns. Patterns in a period of strong hydrological forcing revealed a disruption of diel and semidiel patterns for several days with a general restoration of patterns thereafter. Both diel and seasonal data suggest that abundant submerged aquatic vegetation in the study area was the main primary producer component driving diel and seasonal DO and pH patterns.
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    Relationships among Escherichia coli (E. coli), Total Suspended Solids and Flow for Three Northern Virginia Subwatersheds: Rabbit Branch, Upper Accotink Creek, and Daniels Run
    (2013-10-02) Washington, Marissa
    This project was designed and completed to satisfy the requirements for the M.S. Program in Environmental Science and Policy at George Mason University. Three sites located in Fairfax, Virginia residential areas were chosen to monitor Escherichia coli concentrations between May 18th and July 19th, 2013 and to examine the relationship of E. coli to stream flow, total suspended solids (TSS) and impervious cover. Each site was visited a total of 9 times during the study period. Analysis of data from these sites indicated that they are not meeting the Virginia Department of Environmental Quality (VDEQ) standard of 235 CFU/100 mL for E. coli in recreation streams. The range for E. coli over all three sites was 78 - 19,100 CFU/100 mL. There were also nine samples in which the levels were above the range of the test procedure (>20,000 CFU). This study also suggested that E. coli may respond to increased impervious cover, TSS and rainfall; however, due to a high degree of variability most of the relationships were not significant. Visual examination of the watersheds indicate that there are multiple potential upstream non-point sources including human and animal activity that could contribute to elevated E. coli levels. Because these sites are in violation of state water quality standards, it is imperative that the County and City Storm Water Planning Divisions further investigate and devise plans to fulfill the purpose of the Clean Water Act. Two of the three sites, Daniels Run and Rabbit Branch, could benefit from projects that have been proposed.
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    An Ecological Study of Gunston Cove - 2011
    (2012-11-27) Jones, R. Christian; de Mutsert, Kim
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    An Ecological Study of Gunston Cove 2010
    (2011-12-13) Jones, R. Christian; Kraus, Richard
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    The influence of past and future urbanization on watershed nitrogen export and hydrology dynamics in two mid-Atlantic watersheds in Fairfax, Virginia
    (2011-10-21) Albert, Ryan
    This study examines urban land use change and its impact on watershed hydrology and nutrient loading in the Accotink and Pohick watersheds in Fairfax County, Virginia. The dissertation explored the amount of urbanization in the watersheds over the past 30 years and the impact of that urbanization on nitrogen loadings and stream hydrology. Further, it examined different projections of future urban development in the watersheds and how urbanization may affect nitrogen loadings and hydrologic changes. It was hypothesized that deterioration in hydrologic conditions and increases nitrogen loadings would be notable. Land use was estimated from 1975 to 2004 using a combination of remote sensing and demographic data, which was given the name of the Household Method. Adjusted land use projections from an existing study generated by the SLEUTH model and projections using the household method were used to estimate future land use. These land use estimates were input into several analytical tools, including the hydrologic component of HSPF, L-THIA, and export coefficient-based approaches. Water quality data collected by George Mason University and the Norman M. Cole Jr. Pollution Control Plant are available at four sites from 1984-1992. Data were also collected on 24 occasions in 2005 at four sites in the watersheds as part of this dissertation. Nitrate-N, ammonia-N, total phosphorus and soluble reactive phosphorus were compared between watersheds using statistical techniques and a multiple regression loading model (LOADEST); focus was given to nitrogen. Physical parameters, including conductivity, dissolved oxygen, pH, and temperature were also analyzed. Modeled and observed results indicate that significant changes correlated with increased urbanization have occurred to the hydrology of these watersheds. Furthermore, without implementation of effective Best Management Practices (BMPs), significant alterations in hydrology will continue into the future. Nitrogen loadings have also increased and will likely continue to increase without effective BMPs, although the increases in nitrogen loading do not pose a significant a risk to the streams themselves. However, these increased nitrogen loadings may pose a potential risk to the Chesapeake Bay ecosystem.
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    An Ecological Study of Gunston Cove 2009
    (2010-12) Jones, R. Christian; Kraus, Richard
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    Bioassessments of the Bull Run Watershed. 1998-99
    (2000-07-24) Jones, R. Christian; Arciszewski, Joanna
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    Bioassessment of Spout Run, Clarke County, VA
    (2002-08-30) Jones, R. Christian; Hansen, Ryan