- Effect of Visibility on Maintenance Investment and Consequent Performance of Urban Stormwater Control Measures , JOURNAL OF SUSTAINABLE WATER IN THE BUILT ENVIRONMENT (2022)
- Carbon storage potential in a recently created brackish marsh in eastern North Carolina, USA (vol 127, pg 579, 2019) , ECOLOGICAL ENGINEERING (2021)
- Event-scale hysteresis metrics to reveal processes and mechanisms controlling constituent export from watersheds: A review , WATER RESEARCH (2021)
- Effects of drying and rewetting cycles on denitrification and greenhouse gas emissions in normally saturated organic substrate , (2020)
- Floating treatment wetland retrofit in a stormwater wet pond provides limited water quality improvements , ECOLOGICAL ENGINEERING (2020)
- High-frequency, in situ sampling of field woodchip bioreactors reveals sources of sampling error and hydraulic inefficiencies , JOURNAL OF ENVIRONMENTAL MANAGEMENT (2020)
- Processes and mechanisms controlling nitrate dynamics in an artificially drained field: Insights from high-frequency water quality measurements , AGRICULTURAL WATER MANAGEMENT (2020)
- Response of Drainage Water Quality to Fertilizer Applications on a Switchgrass Intercropped Coastal Pine Forest , WATER (2020)
- Response of Nutrients and Sediment to Hydrologic Variables in Switchgrass Intercropped Pine Forest Ecosystems on Poorly Drained Soil , WATER AIR AND SOIL POLLUTION (2020)
- Temperature sensitivity of nitrate removal in woodchip bioreactors increases with woodchip age and following drying-rewetting cycles , ENVIRONMENTAL SCIENCE-WATER RESEARCH & TECHNOLOGY (2020)
NCDOT has installed and maintains hundreds of stormwater control measures (SCMs) across the state, and which must be routinely inspected and maintained to ensure they continually function as designed. The frequency of inspection of these controls varies, depending on the type, from multiple times a year to annual inspection only. Additionally, the frequency of â€œroutineâ€ maintenance (e.g., mowing and trash removal) also varies depending on type and location. For SCMs with infrequent inspection and/or routine maintenance, there is a lower chance of catching and remediating possible failures in a timely manner, which can lead to costly repairs. Therefore, there is a need to develop methods for low-cost, routine SCM monitoring such that timely action can be taken when problems first occur. There are unexplored opportunities in using low-cost camera technologies (e.g., security cameras) to continuously and visually monitor SCMs that may be visited infrequently. This project will utilize image data of an SCM type of interest from an existing low-cost camera system and exploit geometric, appearance, and semantic information to determine which areas have changed over time. Computational methods will be developed to account for changes in illumination and areas that are not of interest (e.g., background noise). Additionally, these changes will be coupled with precipitation data (such as from the Multi-Sensor Precipitation Estimates (MPE) service) to determine the likelihood that the change requires a maintenance action by a human inspector (i.e., after large precipitation events), and/or to perform targeted visual change detection using image data before and after these events.
This proposal aims at better understanding the Carbon cycle in freshwater impoundments. The expected changes in weather patterns have the potential to dramatically change the general role of freshwater reservoirs as global sinks to global carbon sources. For this, we will use a suite of novel sensors and models. To decouple the temperature and oxygen cycles, we will use a drinking water reservoir in Virginia where the hypolimnion can be oxygenated at will. The data obtained from high frequency sensors developed at NC State will capture the effect of oxygenation on the C cycle. The data will serve to further develop and models, which will be used to simulate for other reservoirs the potential impacts of changes in temperature and storm mixing.
The overall objective of this project is to evaluate the hydrological effects of converting pasture to eucalyptus plantation. Field research study sites for the project consists of two instrumented watersheds at La Corona, one control pasture watershed and one treatment watershed planted to Eucalyptus in 2013. The work performed for the project includes support for field collection of data, data processing, data analysis and archiving, data presentation and publication, data sharing and collaboration with other researchers. Similar work funded with existing funds will be performed on the data collected from two other watersheds at La Corona, one treatment watershed planted with loblolly pine in 2003 and a second control pasture watershed monitored since 2000.
Corn earworm (Helicoverpa zea Boddie) has been the target of black light and pheromone trapping networks across North Carolina for decades. Information generated by this network has been communicated to soybean growers through traditional extension meetings and digital resources (e.g., blogs, twitter, websites). Although the information provides an indication of adult corn earworm activity, the time lag between moth counting and online data availability limits growers ability to time scouting activities, determine economic thresholds, and apply insecticides. Automation of earworm specific trapping networks can address this need by eliminating the observer via seamless data integration into web and phone app interfaces. Moreover, automated traps require less effort to maintain than conventional black light systems that catch many different moth species. As a result, the number of traps could be expanded to monitor moth activity in areas that are not served by the NCSU Earworm Trap Network.
A large farm located in extreme eastern Hyde County uses intense drainage practices to allow for agricultural operations and to maximize crop yields. Currently, water management on the farm requires pumping of excess agricultural drainage water into the Pamlico Sound. Multiple stakeholders, which include members that have in some cases, been historically adversarial, have forged a partnership to develop a large scale restoration and water management plan that will encompass over 7,200 acres of land. This plan will significantly reduce pumped agricultural drainage water to the Pamlico Sound, and reroute this water through historical drainage paths that will enhance the hydrology and habitat on approximately 4,200 acres of forested wetland that have been drained (it is believed that this area formed a natural drainage way flowing northwest in the direction of the Alligator River). If this project is successful, it could signal a pivotal change in scale and acceptance of these types of projects, because our planning thus far appears to have minimized required socio-economic trade-offs between stakeholders. The current conceptual plan for replicating and restoring natural drainage patterns within this area include plugging of farm ditches, land contouring, creating impoundments for water reuse and migratory waterfowl habitat, and planting of native vegetation where needed. To reduce drainage outflow directly to the Pamlico Sound via pumping, this farm land to be restored may provide a more ecologically sound area to redirect a portion of agricultural drainage water. Hydrology in the restoration area which was historically common to pocosin ecosystems can be restored. In addition, as pumped drainage water flows through this area, sediment, nutrients, and bacteria contained in this water can be effectively removed through biogeochemical processes unique to wetland ecosystems. Some of this drainage water will also be available for reuse by the farm. Reuse coupled with infiltration and evapotranspiration in the restored areas will also reduce the net volume of water leaving the confines of the farm. The Department of Biological and Agricultural Engineering at North Carolina State University proposes to provide leadership in finalizing the design and overseeing construction of Phase I of this project. In addition, it is crucial that the initial hydrologic modeling efforts that addressed the feasibility of this project be intensified to determine how water will be managed following construction. Our initial estimates are that pumping costs will be reduced, and both the pollutant load reduction to the sound and assimilation capacity of the wetlands will be high - a win for all stakeholders. However, these hypotheses must be tested using long-term models that will be calibrated and validated with field and laboratory data obtained during this proposed effort. This overall project will serve as a demonstration of how environmental and water quality projects can be implemented in conjunction with agricultural operations. In addition, it will serve as an example for other farms in the watershed/drainage district that will lead to future restoration projects with additional water quality benefits. These studies proposed will be coupled with reporting and education at local meetings to solidify current fragile partnerships. Failure to do so may stalemate this and future projects of this scale.
Nitrogen (N) loading to our streams and rivers has improved since the mid-1990s through management practices that have reduced discharges from stormwater and agricultural sources. However, load reductions to surface waters like the Neuse River have not reached targeted goals, and eutrophication remains a major concern. Problems with N fluxes from our watersheds are expected to continue and worsen. Projected population increase and shifts in precipitation patterns will lead to significant increases in N loads to our surface waters, requiring new management strategies to reduce inputs by an additional 20-30%. Large facilities that treat wastewater for major municipalities are most heavily scrutinized, but what about the hundreds of small towns and communities that do not have advanced wastewater facilities? Often overlooked, the discharge limits for smaller systems for ammonia-nitrogen (NH4-N) are often high (10 mg/L) or even non-existent. Package plants that use aerobic processes to treat wastewater in smaller, rural communities often successfully treat NH4-N to low levels through the process of nitrification, but the effluent contains the byproduct nitrate-nitrogen (NO3-N). Discharge of this form of nitrogen is often similar to loads discharged from agricultural facilities on an areal basis and will continue to contribute to eutrophication problems if left unchecked. To help meet current and future N reduction goals, the time is now to address these often overlooked sources using alternative technologies. Installation of constructed wetlands, known for high N removal potential, placed strategically in the landscape to intercept N from smaller rural wastewater treatment facilities, could be a solution to help NC get closer to its N reduction goals. Constructed wetlands are often used across the country and the world for advanced nitrogen removal from wastewater. In NC, these systems have been successful, but very few are in operation. The objectives of this research and outreach project are 1) to help small towns improve nitrogen removal performance of older existing constructed wetlands and 2) advance the understanding and use of constructed wetlands to remove nitrogen from domestic and municipal wastewater. 3) demonstrate the impact constructed wetlands could have on overall watershed N reduction when coupled with existing wastewater package plants.
Denitrifying bioreactors have been identified as holding great promise to play a crucial role in reducing nitrogen pollution from agricultural fields. The thousands of bioreactors needed to significantly decrease nitrate concentrations and loads on a regional scale, and the major technical and financial tasks that this entails, demand that we transform our approach to their research, their design and their management to optimize and maintain their nitrate removal potential. Bioreactors can no longer be taken as â€˜black boxesâ€™, but rather the hydraulic and biochemical processes and their kinetics inside the beds must be quantified, modeled and accurately predicted in order to optimize nitrate removal at the bioreactor scale, across a gradient of substrate, climate and hydrological functioning. We are proposing a laboratory, field and modeling study to provide novel science-based tools and guidelines needed to improve, optimize and maintain removal efficacy of existing and future bioreactors. For the first time, we will open the 'black box' using state of the art continuous sensors for water quality and gases to entangle and quantify the tighly coupled hydraulic and biochemical processes inside the beds. From the high resolution data in time and in space inside the beds, process kinetics from the lab and three field bioreactors representing distinct pedo-climatic functionings, will be used as necessary benchmark data to calibrate a physically-based model. The model will be used to explore optimum designs, and â€˜rejuvenatingâ€™ and hydraulic management, which will yield optimum long term nitrate removal for acceptable gaseous and aqueous emissions.
This project (â€œUsing Smart Control and Real-Time Data Collection to Improve SCM Design and Performanceâ€) aims to explore real-time, â€œsmartâ€ control of the hydrologic and water quality performance of two existing stormwater control measures (SCMs) in North Carolina, a wet retention pond and a wetland. â€œReal-time controlâ€ in this scope of work refers to releasing water from an algorithm-controlled valve from two existing SCMs based on continuous weather forecast data. The high-resolution data portion of the project coinciding with the real-time control aims to collect the most precise and resolute water quality data from a stormwater device in North Carolina to date. The overall goal of both components is to be able to design more efficient and size-appropriate, process-based SCMs in the future. NCSU will retrofit two outlet structures with a sub-contracted control device that optimizes water levels in the systems. In addition to that, we will research more precise pollutant concentrations both entering and leaving these SCMs, combining to provide far more design details and optimization potential for future installations of these systems.
There is a lack of research and understanding on the immediate, mid-, and long term effects of stream restoration projects on water quality. NCDOT partnered with NCFS and NCSU to perform in-stream monitoring of water quality both pre- and during TIP and stream construction under RNS 4105. However, additional data collection & analysis is needed to get an overall, clear picture of the effects on water quality that occur throughout the various stages of a stream restoration project by continuing this effort through the post-construction and stream restoration monitoring phases. In this project, we will continue the acquisition of high frequency flow and water quality data at the existing up, middle and downstream stations. This will involve biweekly field servicing to retrieve data and water samples acquired automatically. Flow will be calculated after stage and velocity will be carefully corrected. Spectral absorbance data will correlated with concentration values obtained in the laboratory to create/validate water quality rating curves. Sediment properties (porosity, bulk density, diagenetic activity) will be quantified, as well as the ability of the stream substrate to retain nitrogen, using the method devised during project RNS 4105. The results of the project RP 2017-26 (RNS 7101) (post-restoration) will be compared to those of RNS 4105 (pre- and during construction) to describe the overall effects of a stream restoration in the Coastal Plain on NC.
Increasing urbanization and agricultural impacts have rallied efforts for mitigating societyâ€™s impact on water quality. North Carolina has passed a wide range of measures to regulate discharges, point and non-point, to surface waters including StormWater Control Measures (SWCM) and Total Maximal Daily Loads (TMDL). Improvements in water quality have been observed, however, continued development and growth expected over the several decades will put increasing strains on the stateâ€™s waters and current treatment infrastructure. Additionally, changing atmospheric composition and mutable precipitation patterns will require existing practices to perform as good or better to maintain good water quality. Many current practices implemented around the state are yesterdayâ€™s solutions to todayâ€™s conditions when we need to be refining solutions to handle tomorrowâ€™s crises. Floating treatment wetlands (FTW) are an emerging practice in water quality control measures. Free-floating vegetation is suspended in the water column using a soilless support matrix. Plants are grown hydroponically at sites of wastewater collection rather than rooted in the soil of the system. Theoretical benefits of this method are numerous. Plant roots are located in the water column rather than the soil increasing access to nutrients and facilitating plant uptake. Hanging root mats provide high surface area for biofilms for microbial water treatment. Numerous studies have shown reductions in phosphorus and nitrogen; both contaminants are of concern for the Tar-Pamlico and Neuse River Basins and both known to cause spikes in toxin-producing algal blooms found in stormwater ponds. FTW require no additional land requirements beyond existing infrastructure and do not significantly reduce the storage volume of the collection system. These systems are easily deployed retrofits for existing infrastructure that can provide immediate and significant water quality improvements. Despite obvious water quality benefits, use of FTW is still limited around the state. This may be for several reasons, including: misunderstanding of costs or lack of funding for FTW; lack of convincing results of treatment benefits; lack of understanding of the processes responsible for pollutant removal. Most importantly there is little to no buy-in or information from state agencies for these systems. The NCDWQ BMP Manual currently gives no information or pollutant reduction credit for FTW. This proposal aims to address three of the issues inhibiting implementation of FTW. The project itself will be broken up into three separate goals: - Goal #1 : Evaluating performance and understanding processes of FTW systems using new technologies developed by the authorâ€™s lab group to determine usefulness as a water quality tool. - Goal #2 : Concurrently performing a comprehensive literature review on all research on FTW with the objective of developing performance estimates for given pollutants. This extensive review will be shared with regional and state stakeholders as consolidated knowledge to inform future WQ policy decisions. - Goal #3 : Dissemination of results of this study, including both the FTW mesocosms/field-scale testing and comprehensive literature review, to local and state agencies in order to increase state-wide awareness and understanding of these systems as a potential water quality tool.