Sunday, February 17, 2013
Auditorium/Exhibit Hall C (Hynes Convention Center)
The term indirect potable reuse is an occurrence in any watershed for a drinking water treatment plant (DWTP) that contains discharges of wastewater. It's not uncommon to have a substantial portion of the source water for these DWTPs originally derived from the upstream wastewater contribution. The goal of this project is to develop a model that estimates the amount of wastewater effluent that is present within drinking water treatment plants. Increases in effluent concentrations have the potential to be exaggerated with respect to temporal variations in stream flow. Future variances in stream flow will influence the impacts of wastewater treatment plants on downstream drinking water treatment plants. Heightened concern of this issue is given from uncertainties in changes of base flows due to climate change impacts. This study sheds light unto the variations in wastewater effluent proportions due to altering stream flows. This interdisciplinary project will also look into some of the social science aspects of this topic relating to the publics' perception. In order to manage information we must understand the underlying informal institutions that are present in the general public. An important portion of this research is aimed towards conducting social surveys in order to find the current perceptions that lie in the public. The focus is set upon finding the extent to which the public is aware that wastewater effluent resides in their drinking water, to find what percent is “acceptable” within the tap, and the degree to which their location affects their willingness to consume the water. A three-city case study will be used to analyze the social portion of the project through an online survey; the cities are to include Philadelphia-PA, Atlanta-GA, and Las Vegas-NV. The indirect reuse model is being developed within the ArcGIS 10 framework. Vector and raster layers have been added to the database from a variety of sources. Sources include the National Hydrography Dataset (NHD), USGS, and EPA. Model Builder is currently being used to design a network flow analysis that calculates the downstream wastewater effluent concentrations. It is important that the model is a good representation of actual effluent values. Analysis will be performed to validate the model with analytical lab work of the wastewater tracers sucralose and primidone. Preliminary analysis has been conducted for 25 cities across the U.S, previously found by EPA to have the highest wastewater impacts in 1980. The wastewater percentages ranged from 0.2% to 12.3% during average flow conditions, and 0.3% to 52.7% during low flow conditions.