CAREER: Impacts of Lake Browning on the Photochemical Fate of Organic Micropollutants

Lakes are key natural water systems that provide critical services to people and ecosystems including the supply of drinking water, fishing, recreational activities, and climate regulation. Long-term water quality trends in lakes often serve as indicators of local, regional, or global environmental changes. Many inland lakes in the State of New York and the northeastern regions of the United States are experiencing browning, an increase in water color due to changing organic matter compositions, hydroclimatic forcings, and land use patterns.

Many of these lakes also receive significant inputs of organic micropollutants (OMPs) from their watersheds. However, a fundamental understanding of the impact of browning on the photochemical transformations and fate of OMPs in lakes has remained elusive. The overarching goal of this CAREER project is to characterize and quantify the impact of browning on the sunlight-driven transformations of OMPs in inland lakes of the State of New York.

The successful completion of this research will benefit society through the generation of new data and fundamental knowledge to support the development of adaptive lake monitoring programs and water treatment practices to manage and minimize the impact of lake browning on water quality in the State of New York. Further benefits to society will be achieved through student education and training including the mentoring of a graduate student and a high-school student summer intern at Syracuse University.

Many inland lakes in the State of New York and the northeastern regions of the United States are experiencing an increase in water color (browning) due to changing compositions of their organic matter while receiving significant inputs of organic micropollutants (OMPs) from their watersheds. For communities and utilities that rely on lakes for the supply of drinking water, lake browning might lead to an increase of water treatment costs (e.g., increasing chemical and energy consumption) to remove OMPs and achieve the drinking water quality standards required to protect human and ecosystem health.

However, there are critical knowledge gaps in the fundamental understanding of the impact of browning on the reactivity and fate of OMPs in lakes. This CAREER project will address these knowledge gaps. To advance this goal, the Principal Investigator (PI) proposes to evaluate the impacts of browning-induced changes in lake organic matter composition and reactivity on the photochemical (sunlight-driven) transformations of OMPs in the State of New York (NY) inland lakes.

The specific objectives of the research are to: (1) Conduct a broad characterization of the photoreactivity of inland lake waters in collaboration with the NY Citizens Statewide Lake Assessment Program to identify key organic matter properties driving the inter-lake variability in photoreactivity; (2) Examine the impact of allochthonous organic matter from acid-impacted lake watersheds on the photochemical transformations of OMPs in lakes; and (3) Evaluate the impacts of autochthonous organic matter from algal blooms and the effluents of wastewater treatment plants on the photochemical transformations of OMPs in lakes. The successful completion of this project has the potential for transformative impact through the generation of new data and fundamental knowledge to support the watershed management decisions and water treatment practices that will be required to manage and mitigate the impact of lake browning on water quality.

To implement the educational and training goals of this CAREER project, the PI will develop and incorporate new inquiry-based modules into three environmental engineering courses at Syracuse University (SU). In addition, the PI plans to develop and deliver outreach programs at SU to 1) broaden the participation of students from underrepresented groups in water quality research and 2) promote environmental literacy among lake community members and the public in collaboration with the NY Citizens Statewide Lake Assessment Program.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.