RAN: Redesigning the American Neighborhood Project
In Stream vs. Land-based Sources of Water Pollution
Joel Nipper, current doctoral dissertation research project in Natural Resources at the University Vermont
Development of land surfaces can contribute to water quality impairment through a number of mechanisms. First, the process of development eliminates natural environmental features as structures, roads, and other infrastructure are built. The developed land cover may include a high degree of impervious and compacted surfaces in place of the pre-development pervious land cover. This alone can adversely affect the hydrology of the area and cause water quality problems if not properly mitigated.
In addition to the effects of development and infrastructure on hydrology, human activities on the developed land surfaces can have their own specific impacts on water quality. For example, a rock salt storage facility may leach salt to the environment, whereas residential development may have some combination of pollutants generated by lawn fertilizer, pet wastes, septic system discharges, and other sources. Any activity on the land surface has the potential to deliver pollutants to receiving waters if not properly managed.
When a water quality problem is observed at a point downstream of developed land cover, it can be difficult to accurately determine the source of the pollutants of concern. In addition to direct land-based sources, there may be other development-related sources. Pollutants delivered to downstream locations as a result of stream channel erosion are one such case.
For example, a pollutant not currently generated on the land surface at all may be mobilized from stream channel deposits by development-driven high flow conditions. For other pollutants, the quantity washed off the land surface may be augmented by materials eroded from the stream channel. This can make it difficult to identify how much individual sources are contributing to total watershed loads.
This uncertainty concerning the sources of pollutants being delivered to downstream locations can make it more difficult to formulate effective storm water management strategies. In this research effort, we are attempting to determine the relative contributions of surface washoff and channel erosion to total pollutant loads in a small, mixed-land-use watershed. To address this question, we are using a combination of in-stream and within storm drain sampling and simulation modeling. Together, these data sets will allow us to better understand which sources are contributing what proportion of watershed pollutant loads.
Prior to his doctoral work in The Rubenstein School at the University of Vermont, Joel Nipper earned his BS in Environmental Sciences at SUNY Plattsburgh in 2005 and an MS in Environmental Pollution Control from Penn State in 2006. His research interests include the application of field investigation and simulation modeling to water quality problems.
Last modified October 16 2009 12:38 PM