Assessing Threats of Changing Climate to Drinking Water Quality
Institution: University of Maine
Sponsor: Maine Water Institute (WRRI Program)
Many lakes in New England are currently clean enough to be exempt from expensive filtration processes required by federal legislation. However, with changes in climate and air pollution, many lakes are undergoing a process referred to as “brownification”, in which the tea-colored stain in lakes from dissolved organic carbon (DOC) is increasing. While increasing DOC concentrations have been documented in many lakes in the Northeast, it remains unclear whether these changes are affecting the physical and biological structure of lakes, thereby threatening drinking water quality. The objectives of this project are to determine whether vertical temperature gradients and abundance of nuisance algae are affected by increasing DOC concentrations. To address these objectives, physical and biological changes will be investigated in three sets of lakes: 1) three of the sixteen US EPA Long-Term Monitoring (LTM) lakes in Maine in which DOC has increased since 1985; 2) three LTM lakes with no increase in DOC; 3) Floods Pond, the drinking water source for the city of Bangor. Paleolimnological methods will be used to assess these changes over the past century, while limnological sampling and temperature probes will be used to assess current and future conditions. Understanding the links among DOC, algal communities, and climate-relevant lake thermal structure will aid drinking water utilities in assessing the degree of risk and required treatment strength with DOC fluctuations in their water source.
- Jasmine Saros, Climate Change Institute (team leader)
- Sarah Nelson, Senator George J. Mitchell Center