ANALYSIS AND MAPPING OF SOURCES OF CONTAMINANTS OF EMERGING CONCERN IN LAKE THUNDERBIRD, NORMAN, OK

A contaminant of emerging concern (CEC) is defined by the USGS as any synthetic or naturally occurring chemical or organism that is not commonly monitored in the environment, but has the potential to enter the environment. Four water sampling events at Lake Thunderbird in Norman, OK have been completed in the past year, each event representing a season. Water samples were analyzed for 95 CEC. The CEC are divided into four categories: 1) industrials, 2) pesticides, 3) pharmaceuticals and personal care products (PPCP), and 4) “others”. June sampling recovered eight detections, October had 21, January had 14, and April had the most detections at 32. The motivation for detecting CEC concentrations in Lake Thunderbird came from the City of Norman proposing an indirect potable reuse (IPR) project; this project would allow water to be recycled with Lake Thunderbird acting as an environmental buffer, after it is treated at the Norman Water Reclamation Facility (NWRF). The goal is to analyze the CEC concentrations in the lake, evaluate periodic tendencies, and identify probable sources for the detected CEC. Initial assessments of the data indicate that CEC are likely derived from seasonally variable sources, such as lawn applications (with higher number of occurrences during winter) and septic systems (anomalous incidence during summer season). The findings of this research project will be reported to all stakeholders so that background CEC concentrations in the lake are documented and necessary advanced water treatment can be designed at the NWRF before the IPR project commences. If time and resources are not a constraint, data will be collected showing neighborhoods that use septic tanks, densely populated areas with regular lawn maintenance, and agricultural areas that are upslope of Lake Thunderbird and that data will be mapped in ArcGIS to show potential sources of runoff contamination. Follow up CEC measurements are fundamental for the confirmation of the effectiveness of the proposed counteractive plans.