Track A-4. Measuring and mapping nutrient loading
Utilizing geochemistry, soil properties, and oxygen isotopes for a simplified mass balance to quantify dissolved nitrate storage and flow within vadose and shallow saturated zones
Diane M. Lamb, Lincoln College
Lake Bloomington, a major water reservoir for Bloomington, Illinois, has a watershed land use of 90.3 percent agricultural. Periodically, the lake's nitrate as nitrogen (NO3-N) concentration exceeds the U.S. Environmental Protection Agency’s legal standard. To investigate, the city has established a research farm adjacent to the lake and has been working with different fertilizer application methods. Vadose and shallow saturated zone storage and movement is unknown. Research objectives were to enhance understanding of dissolved NO3-N in vadose and shallow saturated zones and create a conceptual model of transport and storage. The investigation included monitoring dissolved NO3-N through time, measuring shallow subsurface physical properties, determining preferential pathways, using measured and regional parameters to quantify nitrate with a simplified mass balance, and modeling groundwater flow through the study area. Vadose zone instruments were installed and used along with the city's groundwater equipment. Groundwater and soil water samples were regularly collected and analyzed. Land surface was surveyed and water levels were monitored. Field saturated hydraulic conductivity was measured at four soil sites for three depths each. Beans grown for half of the one-year study period had no fertilizers, while the second half had added fertilizers for corn. NO3-N concentrations increased with water availability, crop N-fixation, and N-fertilizer, while they decreased through dry periods and harvest. Soil hydraulic conductivity affected storage potential and inhibited transport. The vadose zone was found to store more dissolved NO3-N mass than the shallow saturated zone. Tile drains transported 99 percent of the total dissolved NO3-N output. The N-mass balance was shown to be a viable means to quantify the NO3-N. Preferential pathways did not enhance flow at the farm. A groundwater flow model for the watershed was utilized and calibrated with study data. Understanding of shallow subsurface nitrate activity was acquired through this investigation and subsequently related to the larger watershed.
Diane Lamb is an Illinois licensed professional geologist. She has worked with engineering firms and state agencies on water-related projects and environmental permitting. She has also been a visiting lecturer at several Illinois colleges. Diane received her bachelor of science in geology and master of science in hydrogeology from Illinois State University, graduating magna cum laude in 2004 after successfully changing careers from accounting. She completed two internships with the Illinois Geological Survey before working in environmental consulting. She has served on the executive committee for the Illinois Groundwater Association for seven years. Diane enjoys mentoring students and sharing her passion for the earth and its resources.
The Great Lakes to Gulf Observatory: An interactive geospatial application focused on nutrients in the Mississippi River and its tributaries
Edward Kratschmer, National Great Rivers Research and Education Center
The Great Lakes to Gulf Observatory (GLTG) is an interactive geospatial application that integrates water quality data from multiple sources to better facilitate analysis and, ultimately, knowledge of nutrient pollution, large river ecology, and water quality conditions in the Mississippi River watershed. GLTG's web-based application allows users to dynamically browse, search for, and visualize water quality information on the Mississippi River and its tributaries. The application uses a combination of different respected data sources, including long-term historical datasets and continuous real-time sensors, providing the users with a better picture of water quality in the watershed. Meant to add value to users of existing datasets and projects, the application's features, visualizations, and design allow researchers, communities, and decision makers to better understand nutrient inputs and loads, expedite data-to-knowledge-to policy connections, enhance risk management decisions, empower emergency response, and inform long-term strategic planning. With the first phase of the project focused on nutrient pollution, the application and its infrastructure are relevant to state nutrient reduction strategies, watershed planning efforts, and focused watershed initiatives. Led by the National Great Rivers Research and Education Center (NGRREC), data integration and visualization occurs within a cyber-infrastructure framework constructed in collaboration with the National Center for Supercomputing Applications and Illinois-Indiana Sea Grant at the University of Illinois.
Ted Kratschmer is the field station manager and science liaison at NGRREC in Alton. He also works as the NGRREC lead on GLTG.
Demonstrating and monitoring nutrient removal in a constructed wetland
Mahsa Izadmehr, University of Illinois at Chicago
As part of a collaboration with a non-profit non-governmental organization, I have gained access to a constructed wetland built in the fall of 2015. My proposed research aims are to perform an aqueous phase nutrient mass balance study on the treatment wetland in conjunction with particle tracer studies to determine the fate of different types of particulates within the system using fluorescent and magnetic tracer particles. There are two hypotheses for this research: Aqueous phase total nitrogen removal (TN) in the wetland will exceed total phosphorus (TP) removal and scouring events from high precipitation flow events will increase TP fluxes through the system to a greater extent than for TN through overland flow of particles. The aqueous phase mass balance will require automated samplers upstream and downstream of the wetland to measure N and P levels in the aqueous phase, which I have completed with the installation of samplers at the inlet and outlet structures constructed on site. An automated weather station has been employed on site to retrieve local weather data. Particle movement will be tracked using four particle tracers both temporally and spatially by Lagrangian sampling of a spatial grid at fixed time intervals. Each type of particle has different fluorescence characteristics, so I can readily separate the transport of each type of particle in mixed samples obtained from the sampling grid. The N and P data prior to, during, and after construction of the wetland will lead to the development of methodologies for cost-effective assessments of wetland nutrient removal and allow for a comparison between the developed model and predicted removal using wetland models.
Mahsa is a PhD student in civil and environmental engineering at University of Illinois at Chicago working on the wetland project to demonstrate and monitor nutrient removal by wetlands in the Big Bureau Creek watershed. Mahsa has experience as an entry-level environmental engineer for one of the Fortune 100 companies, Burns & Mcdonnell consulting engineering company. She has Engineer in Training and Hazardous Waste Operations and Emergency Response certificates as well as a master’s in environmental engineering from the Illinois Institute of Technology. She has experience with variety of engineering software, including Sewer CAD, ArcGIS, and Biowin.