Suburban Storm Drain Water Quality Analysis
Storm water is a major cause of pollution in lakes and rivers because the rain water can easily become contaminated by chemicals and fertilizers that enter the storm drains. The purpose of storm drains is to prevent flooding by draining rain water directly to the lake; however, rain water that enters the lake through these drains is not treated.
The objective of this field study was to analyze the water quality of storm water runoff and the effect of storm water runoff on the water quality of Lake St. Clair.
Eighteen storm water samples were collected from storm drains in St. Clair Shores. A one sample t-test was used to compare standard water quality values in a healthy ecosystem to the average nitrate, phosphate, pH, and dissolved oxygen of the eighteen drain samples. Lake water samples were collected near storm drain outlet pipes before rain and three days after rain. A two-sample t test was used to compare the average nitrate, phosphate, pH, and dissolved oxygen of the lake water samples before and after rain.
It was hypothesized that the storm water runoff would have a higher mean level of nitrate than the standard value (0 mg/L), a higher level of phosphate than the standard value (1 mg/L), a lower pH than the standard value (7), and a lower level of dissolved oxygen than the standard value (10 mg/L). It was also predicted that the water quality of the lake would become more polluted after it rained due to the storm water runoff. The results from the experiment concluded that the levels of nitrate and phosphate were higher in storm drains than the environmental standard, and the overall water quality of the lake was not different before and after rain, though the dissolved oxygen was greater post rain.
Research Conducted By:
Lauren Livernois
Lake Shore High School
Elizabeth Stacheit
Lake Shore High School
Warren Consolidated Schools