Limited macroinvertebrate biodiversity in Lytle Creek that runs through downtown Wilmington, Ohio has been documented over decades with the lowest in Lytle Creek at Sugar Grove Cemetery. Lytle Creek, a tributary of the Little Miami River, is a conduit for storm water and wastewater from an airport, downtown storm water with input from local businesses, and a wastewater treatment plant. This study was conducted to see if heavy metal pollution in the sediment, water quality, and Escherichia coli (E. coli) could be contributing factors in reduced macroinvertebrate populations. Eight sites were chosen for sediment sampling to measure trace metals. Mercury (Hg) using cold vapor atomic fluorescence spectrometry. Aluminum (Al), arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), strontium (Sr), and zinc (Zn) were determined by inductively-coupled plasma optical emission spectrometry (EPA method 200.7). Mercury concentrations ranged from 0.0120-0.2920 mg/kg dry wt. The highest level of mercury was found at one of the three areas we collected sediment samples from at Lytle Creek at Sugar Grove Cemetery, at a value of 0.2920 mg/kg dw, which exceeded threshold effect concentration (TEC) of 0.18 mg/kg dw. Mercury values were also high at Xidas Park, but it was just below (TEC). Lead was above (TEC) at Xidas Park, Sugar Grove Cemetery and the Fairborn site. Two areas collected from Xidas Park had values ranging between 36.95-37.93 mg/kg dw. Lytle Creek at Sugar Grove Cemetery values ranged between 48.76-55.41 mg/kg dw, and the Fairborn site had a value of 38.70 mg/kg dw. These values exceeded (TEC) of 35.8 mg/kg dw. The downtown tributary to Lytle Creek at the Xidas Park site, empties into Lytle Creek at Sugar Grove Cemetery indicating lack of biodiversity in Lytle Creek may be caused by runoff into storm drains in downtown Wilmington. More samples were taken at Xidas Park and one in Fairborn, OH downtown Hebble Creek for comparison, to verify the validity of the initial Pb results.
Five sites were chosen to monitor water quality parameters over a six-month period, February 2017 to July 2017. Fluoride (F-), chloride (Cl-), nitrite (NO2-), bromide (Br-), nitrate (NO3-), phosphate (PO43-), and sulfate (SO42-) were determined using ion chromatography (EPA method 300.1). Total nitrogen was found at a value of 6.740 mg/L, which could be attributed from fertilizer applied on plants found at that area. There was a steady flow of nitrate (NO3-), nitrite (NO2-) and sulfate (SO42-) in Lytle Creek and Indian Run. Phosphate (PO43-) concentrations were below limit of detection, except for Lytle Creek downstream from the treatment facility was found at a value of 3.463 mg/L.
E. coli samples were determined using SOP 6.3 (E. coli and coliform enumeration of water samples) (Russell, 2011). E. coli values were high before and after a rain event. The highest concentration we found was at Lytle Creek downstream from the wastewater treatment plant (WWTP), it was found at a value of 12,000 CFU/100 mL.
In the end, Xidas Park, not discussed in previous Ohio EPA studies, turned out to be the worst contaminated site of all.