Final Report: Ensuring Safe Drinking Water in Lake Erie: Quantifying Extreme Weather Impacts on Cyanobacteria and Disinfection Byproducts (DPBs)

EPA Grant Number: R835192
Title: Ensuring Safe Drinking Water in Lake Erie: Quantifying Extreme Weather Impacts on Cyanobacteria and Disinfection Byproducts (DPBs)
Investigators: Lee, Jiyoung , Liang, Song , Shum, C.K.
Institution: The Ohio State University
EPA Project Officer: Hiscock, Michael
Project Period: June 1, 2012 through May 31, 2016
Project Amount: $748,902
RFA: Extreme Event Impacts on Air Quality and Water Quality with a Changing Global Climate (2011) RFA Text |  Recipients Lists
Research Category: Air Quality and Air Toxics , Water Quality , Climate Change , Air , Water


Under increasing anthropogenic warming, with expected consequences of intensified extreme weather events, Lake Erie, already with excessive nutrients from intensive agriculture and sewer overflows from metropolitan areas, is prone to see its drinking water quality further impaired. The central hypotheses of this study were: (1) extreme weather events are correlated with increased nutrients, turbidity and harmful algal bloom (HAB) in the proposed western and central Lake Erie study regions, (2) increased HABs in source water will increase cyanotoxin concentrations in finished drinking water, and (3) HABs in Lake Erie source water will interact with chlorine disinfectants used in water treatment process, which in turn will increase harmful disinfectant byproducts (DPBs) concentrations in finished drinking water. This grave concern has not been considered before.  Thus, our objectives for this project were: (1) to assess of the link between historic weather events, water quality, and harmful algal blooms (HAB) using 10-year satellite and field work data, including water color (phycocyanin and chlorophyll), temperature, turbidity, precipitation, wind, water level, etc.; (2) to determine the impact of cyanobacteria densities and water quality parameters, including nutrient concentrations, on the quality of drinking water source in western and central Lake Erie; and (3) to examine the levels of disinfection byproducts (DBPs) in finished water in the two water treatment plants, located in western and central Lake Erie to examine if HAB affects the DBP levels.

Summary/Accomplishments (Outputs/Outcomes):

From the interdisciplinary approach using historical and current satellite remote sensing and geodetic data, chemical and molecular tools, comprehensive understanding of cyanobacterial dynamics and its influence on drinking water quality in Lake Erie region was possible. We found strong relationship between Microcystis abundance and DBPs, indicating a potentially important role of cyanobacterial blooms in promoting the formation of DBPs in finished water. When compared the western and central Lake Erie water, we observed the same level of total phosphate in Toledo (heavy bloom) and Painsville (no bloom) waters, but a significantly higher level of nitrate in Toledo, indicating the important role of nitrate in promoting Microcystis blooms in current Lake Erie.  Furthermore, our ten year historical data analysis shows strong seasonal and inter-annual patterns of harmful algal bloom in the western Lake Erie region. Among the water quality and weather factors, nitrogen concentration, wind speed, water temperature, precipitation, and solar radiation were the most influential environmental drivers in predicting HABs.


The results from the 10-year HAB data analysis suggest that there are significant spatial and temporal heterogeneities in the importance of environmental variables that can affect the dynamics of HABs and such heterogeneities are related to interactions between hydro-meteorological and water quality (nutrient) factors. More importantly, hydro-meteorological variables have important moderating effects on nutrient variables in driving HABs in western Lake Erie.   In the Toledo raw water (high bloom), toxin-producing Microcystis level was about 100-1000 times higher than Painesville (no bloom, as a control). Microcystin concentrations in the Toledo raw water in 2013 and 2014 ranged between undetectable to ~10.0 µg/L. In the finished water samples, all the samples did not exceed the WHO guideline (1ppb). The abundant Microcystis population in the lake water (drinking water source) could increase the formation of DBPs in finished water. Both TTHMs and HAA5 in Toledo drinking water were higher than those in Painesville. It may be due to the higher concentration of total organic carbon in Toledo source water than that in Painesville. However, both DBPs did not exceed the EPA regulation levels.  When compared MODIS-measured HAB indicators (chl-a and Cyanobacterial Index) with in situ-measured chlorophyll-a, the match between MODIS- and in situ-measured chlorophyll-a was only reliable in the areas with higher chlorophyll-a concentrations, such as western Lake Erie.

Journal Articles on this Report : 3 Displayed | Download in RIS Format

Other project views: All 9 publications 3 publications in selected types All 3 journal articles
Type Citation Project Document Sources
Journal Article Hu C, Rea C, Yu Z, Lee J. Relative importance of Microcystis abundance and diversity in determining microcystin dynamics in Lake Erie coastal wetland and downstream beach water. Journal of Applied Microbiology 2016;120(1):138-151. R835192 (Final)
  • Abstract from PubMed
  • Full-text: Wiley-Full Text HTML
  • Abstract: Wiley-Abstract
  • Other: Wiley-Full Text PDF
  • Journal Article Lee J, Tseng K-H, Zhang F, Lee C, Marion J, Liang S, Shum CK. From satellite to genes: an integrative approach for timely monitoring of harmful cyanobacteria in Lake Erie beach water. Journal of Environment Pollution and Human Health 2015;3(3):70-79. R835192 (Final)
  • Full-text: JEPHH-Full Text HTML
  • Abstract: JEPHH-Abstract
  • Other: JEPHH-Full Text PDF
  • Journal Article Zhang F, Hu C, Shum CK, Liang S, Lee J. Satellite remote sensing of drinking water intakes in Lake Erie for cyanobacteria population using two MODIS-based indicators as a potential tool for toxin tracking. Frontiers in Marine Science 2017;4:124 (11 pp.). R835192 (Final)
  • Full-text: Frontiers in Marine Science-Full Text PDF
  • Abstract: Frontiers in Marine Science-Abstract & Full Text HTML
  • Supplemental Keywords:

    Drinking water, global climate change, disinfection byproducts, microcystin, limnology, geodesy, environmental microbiology, satellite remote sensing, empirical modeling, harmful algal bloom, Great Lakes, Lake Erie, Ohio, OH

    Progress and Final Reports:

    Original Abstract
    2012 Progress Report
    2013 Progress Report
    2014 Progress Report