Recently Funded Projects

Additional projects are currently funded by the Urban Water Consortium and the Stormwater Group.

Faculty Projects

  • Tarek Aziz, NC State University | Predicting the Effectiveness of Artificial Mixing for Controlling Algal Blooms in Piedmont Reservoirs
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    The use of artificial mixing has been proposed as a means of suppressing the formation of algal (phytoplankton) blooms in freshwater and coastal waterbodies. However, there are conflicting reports on the performance of such systems, with sparse data relating to how artificial mixing affects bloom formation in North Carolina (NC) reservoirs. An understanding of the linkages between blooms, artificial mixing, climate variability, and other water quality constituents is critical to effectively managing water supplies and developing useful geo-engineering solutions. In this proposed research we aim to (1) conduct field campaigns in multiple Piedmont reservoirs to measure vertical diffusivity, water quality, and phytoplankton assemblages in natural and artificially mixed conditions, (2) perform statistical (hierarchical) modeling of vertical diffusivity and phytoplankton concentrations to help identify and quantify key biophysical relationships, (3) perform mechanistic water-column modeling to generalize the results obtained in (2), and (4) develop a decision-support tool from the data and analysis performed in objectives (1) – (3) to predict algal type and abundance under different artificial mixing and background physical and chemical scenarios. Findings from this research will provide new insights into the impacts of both natural and artificial mixing in Piedmont reservoirs, and aid engineers and managers in developing strategies to protect the beneficial uses of these reservoirs.

  • James Bowen, UNC-Charlotte | Comparing the Impact of Organic vs. Inorganic Nitrogen Loading to the Neuse Estuary with a Mechanistic Eutrophication Model
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    In the 1980s and 90s the Neuse River Estuary was plagued with algal blooms and fishkills. A model-based total maximum daily load (TMDL) for nitrogen (N) loading was performed in 1999 and regulations to reduce total N loading to the estuary by 30% from a 1995 baseline were implemented. Inorganic N loading to the estuary has been reduced by 15-25%, but organic N and Trent River loading has increased by approximately 15% and 30%. Algal blooms and violations of the water quality criteria for chlorophyll-a still occur throughout the estuary.In a focused one-year study we propose to update the existing two-dimensional mechanistic model of the Neuse River Estuary in order to address the following research questions:
    1. Is the Neuse Estuary equally sensitive, with regard to phytoplankton biomass, to changes in organic inorganic N loading?
    2. Is nutrient assimilation by phytoplankton equally effective for the organic and inorganic fractions of the N loading to the estuary?
    3. Is the model developed in the 1990s still able to accurately predict phytoplankton biomass given the changes in the fractionation and spatial distribution of N loading to the estuary?
    4. To what extent are the changes in distribution of phytoplankton biomass, and the biomass values seen in the estuary in the 2000’s attributable to changes in changes in the N loading?
    5. What role do the bottom sediments play in the cycling and phytoplankton assimilation of organic and inorganic N loading to the estuary?

    The project will leverage efforts by the P.I. to develop the numerical model used for the TMDL and a second model developed to predict the fate and transport of pathogenic bacteria in the Neuse Estuary. These earlier projects provide the perfect starting point for a reexamination of the linkage between nutrient loading and biomass production in the Neuse Estuary.

  • Joel Ducoste, NC State University | Evaluation of Alternative Binder Material to Reduce Sewer Collection System Infrastructure Maintenance and Enhance Sustainability
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    A large fraction of the estimated 3 to 10 billion gallons of untreated wastewater from sanitary sewer overflows (SSOs) is caused by calcium-based fat, oil, and grease (FOG) deposit related pipe blockages. Solutions that effectively protect the collection system from FOG deposit accumulation are scarce. One possible solution is to reduce the FOG deposit’s ability to form and adhere to sewer infrastructure surfaces. In addition, North Carolina is dealing with the aftermath of the discharge of nearly 40,000 tons of coal ash into a major waterway. The increased use of fly ash in infrastructure materials could help offset some of the fly ash created by coal-fired power plants. The objectives of the proposed research are to: (1) Evaluate alternative binder materials used in precast concrete to reduce or eliminate calcium leaching, (2) Evaluate the adhesion properties of FOG deposits on these alternative concrete surfaces, and (3) Assess the structural durability of these alternative concrete materials. This project involves six research tasks. In Task 1, three alternative binder materials will be developed that differ in the amount of calcium. In Tasks 2-4, these alternative binders will be compared with traditional portland cement binders to determine the amount of calcium and toxic chemicals leaching from these materials and the rate of formation and adhesive properties of the FOG deposits. In Tasks 5 and 6, the structural and durability performance of the candidate binder(s) will be performed. The results of this research will offer North Carolinian wastewater municipalities with strategies to maintain a sustainable sewer collection system that are experiencing significant growth and alleviate the potential environmental and public health harm from FOG related SSOs.

  • Nathan Hall, UNC-Chapel Hill | How, where, when, and why: Defining Eutrophication Related Trends in Water Quality for the Middle and Lower Cape Fear River Basin
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    Over the past decade, the Cape Fear River, NC has experienced symptoms of eutrophication that threaten its value as a vital natural resource for recreation, aquatic habitat, and water supply. While there is a perception that water quality is deteriorating and that increased anthropogenic nutrient loading is likely responsible, very few trend analyses for eutrophication-related water quality parameters have been conducted. This project will leverage an expansive, multi-decade water quality dataset collected by NCDENR, the Middle Cape Fear River Basin Association, and the Lower Cape Fear River Project. Statistically robust trend analyses will be conducted at nineteen sites distributed throughout the middle and lower Cape Fear basin for concentrations and fluxes of eutrophication related water quality parameters including nutrients, chlorophyll a, dissolved oxygen, pH, total suspended sediments, and water clarity. The objectives are to determine how conditions have changed, where in the basin, and when in the data records are changes most apparent. Additionally, a recently developed weighted regression modeling approach will be used to determine shifts in seasonality and shifts in relationships of water quality constituents with flow. Such shifts in combination with information on anthropogenic activities in the watershed (i.e. changes in point/non-point sources) will be used to identify likely reasons why water quality has changed. Information gained will provide a broad ecosystem-level characterization of human and climatic influences on water quality over the past 2-4 decades. Determining where water quality is deteriorating or improving, and why will help prioritize management plans and allow for targeted management responses to specific sources of pollution. This information will be greatly needed as NCDENR updates the Cape Fear River Basinwide Water Quality Plan. By establishing historic baseline conditions and water quality trajectories, the project will be of immediate benefit to recently initiated efforts to develop realistic and achievable nutrient targets under the Nutrient Criteria Development Plan. A two day workshop will teach the recently developed modeling technique to NCDENR staff, stakeholder groups, and fellow researchers for use throughout NC surface waters.

  • Avner Vengosh, Duke University | Tracing Groundwater Contamination Near And Away From Coal Ash Ponds in North Carolina
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    Recent discovery of elevated hexavalent chromium and vanadium concentrations in drinking water wells near coal ash ponds has triggered public concerns about the possible migration of coal ash contaminants to aquifer systems adjacent to coal ash-holding ponds in NC. Previous studies have demonstrated that coal ash effluents contain elevated levels of contaminants, and their migration to the environment could increase human health and environmental risks. This proposed study seeks to evaluate the occurrence of toxic contaminants in drinking water wells near and away from coal ash ponds in two focal sites in Salisbury and Belmont, NC, evaluate possible migration of coal ash effluents to the underlying aquifers, and establish reliable geochemical and isotopic criteria combined with hydrogeological data for distinction between naturally occurring and anthropogenic contamination specifically derived from coal ash ponds leaking. The proposed project consists of (1) generating a new geochemical and isotopic database of about 150 drinking water wells near and away from coal ash ponds in Salisbury and Belmont; (2) drilling new monitoring wells for characterization of the hydrogeology, groundwater gradients, and the quality of shallow groundwater adjacent to coal ash ponds; and (3) integrating new and existing water quality databases for drinking water wells, shallow groundwater underlying coal ash ponds, and baseline datasets in NC. The overall objectives of this study are (1) to provide a scientific evaluation of the occurrence and origin of toxic elements such as hexavalent chromium and vanadium in drinking water wells and associated risks to homeowners in affected areas in NC, and (2) determine if coal ash contaminants are indeed migrating to the aquifers near coal ash ponds. The proposed study is based on a wide spectrum of analytical tools including hydrogeology, water quality with high precision detection of hexavalent chromium and vanadium, aquatic geochemistry, and multiple isotopic tracers including oxygen, hydrogen, carbon, boron, lithium, and strontium isotopes. We have already identified drinking water wells and established communication with homeowners in the two research areas, followed by conducting preliminary sampling and establishing an initial dataset of water quality in the two research sites in order to demonstrate our capability to conduct this study. The outcome of this proposed study will be highly beneficial for homeowners who use private wells as their major drinking water source in areas near and away coal ash ponds, as well as state officials for helping to evaluate the human health risks associated with the water quality and in particularly the highly toxic hexavalent chromium in aquifers of North Carolina.

Student Projects

  • Alexandria Hounshell, UNC-Chapel Hill | Hans Paerl, Faculty Sponsor | Role of organic nitrogen to eutrophication dynamics along the Neuse River Estuary, NC
  • Bryan Maxwell, NC State University | Francois Birgand, Faculty Sponsor | Quantifying treatment potential of floating treatment wetlands to benefit North Carolina waters using improved methodology and novel technology
  • Mark River, Duke University | Curt Richardson, Faculty Sponsor | Particle-bound Nutrients in Stormflow: A New Approach for Monitoring and Predicting the N and P Transport and Fate in Watersheds of the NC Piedmont
  • Charles Stillwell, NC State University | William Hunt, Faculty Sponsor | Use of Hydrologic Models to Evaluate Stormwater Treatment Strategies: A Case Study
  • Kirsten Studer, UNC-Chapel Hill | Howard Weinberg, Faculty Sponsor | Impact of Hospital and Patient Discharges on North Carolina Surface and Drinking Water Quality as Measured by Iodinated Contrast Agents

Past Projects & Research Results

WRRI has funded research since the 1960s. A complete list of projects and associated results and report information can be found below. Research reports are housed and accessible through the NCSU Technical Reports Repository.