Water Quality Variability in a Bioswell and Concrete Drainage Pipe, Southwest Lincoln, Nebraska

Abstract The goal of this project is to evaluate the effectiveness of bioswells in protecting water quality from urban runoff. The hypothesis tested in this project is that water in bioswells improves water quality. Water quality in both a bioswell and an underground concrete lined ditch, both containing ground and surface water, were tested for certain water quality parameters. These parameters consisted of: Dissolved Oxygen, pH, water temperature, weather temperature, Total Dissolved Solids, Specific Conductivity, Alkalinity, Total Dissolved Carbon, Chemical Oxygen Demand, and depth and width of the sampling site. An additional contaminant that was looked at was motor oil. This was measured by comparing Total Organic Carbon with Chemical Oxygen Demand. A variety of different methods to measure the water quality parameters were utilized. The concrete site had more stable readings, but much higher water temperatures. However, the bioswell water is mainly from surface water runoff, and the underground concrete lined pipe is from underground water, so the two cannot be directly compared. The bioswell had high readings, especially pertaining to Oxygen Demand, Total Organic Carbon, and Specific Conductivity in early test dates. But, these readings improved as they were filtered though the bioswell. As plant activity increased and the weather began to warm up there were more stable readings. It is concluded that bioswells are an effective way to reduce problems associated with urban runoff pertaining to certain water quality parameters.