Effects of runoff and treated wastewater on water quality in three local waterbodies: Lake Michigan, the North Shore Channel, and the North Branch Chicago River.
Location
SU-215
Department
Environmental Science
Abstract
The Clean Water Act was established in 1972 with the goal of returning all waters in the US to fishable and swimmable conditions. However, we are far from reaching this goal, and most waterbodies in the Chicago area have been identified by the EPA as being impaired for multiple uses. These impairments can be the result of many factors, including land use, runoff, industrial discharge, and discharge of treated wastewater. Our objective was to document differences in water quality among three local waterbodies impacted by different factors. Specifically, in October 2023 we collected samples of water from Lake Michigan (“lake”, which is least impacted by local environmental factors), the North Shore Channel (“channel”, into which treated wastewater from the O’Brien Wastewater Treatment Plant is discharged), and the North Branch Chicago River (“river”, which is impacted by runoff from its relatively large watershed) above the confluence with the channel. Using probes from Hanna Instruments, we measured temperature, pH, electrical conductivity (EC), and turbidity in the field and nitrate and chloride in the lab, and measured phosphate in the lab using colorimetry. Using ANOVA, we found that the mean values of all parameters measured differed significantly among sites, and that many of the pairwise differences among sites were significant as well. Among the more interesting results, we found that: water quality in the lake was uniformly better than the other sites for all parameters; levels of EC and phosphate exceeded EPA standards in both the channel and river; nitrate exceeded standards in the channel; and chloride concentrations were highest in the river (but did not exceed standards). These results provide evidence that discharge of treated wastewater by the O’Brien plant has strong (and negative) effects on water quality in the channel, and that runoff from its watershed has negative impacts on water quality in the river. In the future, we recommend doing sampling throughout the year to see how water quality changes seasonally and after major weather events.
Faculty Sponsor
John Kasmer
Effects of runoff and treated wastewater on water quality in three local waterbodies: Lake Michigan, the North Shore Channel, and the North Branch Chicago River.
SU-215
The Clean Water Act was established in 1972 with the goal of returning all waters in the US to fishable and swimmable conditions. However, we are far from reaching this goal, and most waterbodies in the Chicago area have been identified by the EPA as being impaired for multiple uses. These impairments can be the result of many factors, including land use, runoff, industrial discharge, and discharge of treated wastewater. Our objective was to document differences in water quality among three local waterbodies impacted by different factors. Specifically, in October 2023 we collected samples of water from Lake Michigan (“lake”, which is least impacted by local environmental factors), the North Shore Channel (“channel”, into which treated wastewater from the O’Brien Wastewater Treatment Plant is discharged), and the North Branch Chicago River (“river”, which is impacted by runoff from its relatively large watershed) above the confluence with the channel. Using probes from Hanna Instruments, we measured temperature, pH, electrical conductivity (EC), and turbidity in the field and nitrate and chloride in the lab, and measured phosphate in the lab using colorimetry. Using ANOVA, we found that the mean values of all parameters measured differed significantly among sites, and that many of the pairwise differences among sites were significant as well. Among the more interesting results, we found that: water quality in the lake was uniformly better than the other sites for all parameters; levels of EC and phosphate exceeded EPA standards in both the channel and river; nitrate exceeded standards in the channel; and chloride concentrations were highest in the river (but did not exceed standards). These results provide evidence that discharge of treated wastewater by the O’Brien plant has strong (and negative) effects on water quality in the channel, and that runoff from its watershed has negative impacts on water quality in the river. In the future, we recommend doing sampling throughout the year to see how water quality changes seasonally and after major weather events.