MS Graduate Student
Department of Biological and Agricultural Engineering
NC State University
Twitter: @NCState_Wetland
Target Start Date: August 15, 2024 (Summer start possible)
Project description:
Nutrient loading to North Carolina’s streams, rivers, and lakes has improved since the mid-1990s through management practices focused on pollution from large, advanced wastewater treatment plants, urban stormwater, and agricultural facilities. However, load reductions to surface waters have not reached targeted goals. Eutrophication remains a major concern, particularly in the face of population increases and shifts in precipitation patterns that will likely also increase nutrient pollution.
A shift in focus towards smaller wastewater treatment systems in rural communities offers another strategy for reducing pollution, particularly nutrients. Often overlooked, the discharge limits for smaller wastewater systems for ammonia-nitrogen (NH4-N) are usually high (10 mg/L) or even non-existent. Some technologies simply convert nitrogen to another form without significant reductions. For example, facilities that use aerobic processes to treat wastewater in small rural communities often successfully treat NH4-N to low levels through the process of nitrification, but the effluent contains significant amounts of the byproduct nitrate-nitrogen (NO3-N) which also contributes to eutrophication. Additionally, phosphorus (P) treatment is usually not required and effluent limits are rare. Sometimes, the requirement for wastewater facilities is to simply monitor and report nutrient concentrations without permit limits, but even this requirement is inconsistent across permits and leads to underestimates of nutrient loads delivered to watersheds. Many of these smaller wastewater systems have aging infrastructure, diminished treatment efficiency, and limited budgets and expertise to address these problems.
The NC General Assembly appropriated funds for the purpose of establishing the Innovative Highly Treated Wastewater (HTWW) Program. The program was intended to provide funding to rural towns with distressed wastewater systems that serve less than 10,000 customers to upgrade their wastewater systems. The project is currently underway; five rural towns in NC are being studied for current wastewater treatment performance before and after the installation of new technology. These conventional systems will be compared to a sixth system, a constructed wetland using ecological engineering approaches to treat wastewater. The outcomes of the project will be a) the determination of wastewater treatment improvements with newer technologies compared to a constructed wetland approach and b) an evaluation of if constructed wetlands used in conjunction with traditional wastewater treatment approach could provide a low-cost, low-tech alternative to improve waste water effluent quality and improve watershed health.
The M.S. student will work alongside a team studying enhancements to constructed wetlands for the treatment of wastewater and have the opportunity to participate in various outreach events. Please contact Dr. Mike Burchell (mike_burchell@ncsu.edu) if you have interest or questions about the project.