Grantee Research Project Results
Impacts of Unsewered Residential Development on Groundwater QualityEPA Grant Number: F5B30314
Title: Impacts of Unsewered Residential Development on Groundwater Quality
Investigators: Wilcox, Jeffrey D.
Institution: University of Wisconsin - Madison
EPA Project Officer: Lee, Sonja
Project Period: September 1, 2005 through August 31, 2007
Project Amount: $91,012
RFA: STAR Graduate Fellowships (2005) RFA Text | Recipients Lists
Research Category: Academic Fellowships
Urbanization of rural areas is one of the most significant land-use issues in many parts of the United States. While residential developments near urban centers typically use city water and sewer services, those in rural areas often obtain their water supply from private on-site wells and dispose of wastewater through on-site treatment systems. As more and more rural areas are developed, it is important to understand the impact of wastewater treatment systems on the groundwater that supplies private wells and feeds local streams.
Literally thousands of organic chemicals are used in households daily, including pharmaceuticals, cleaning products, cosmetics, and food supplements. Many of these compounds and their metabolites can be found in domestic wastewater, and ultimately, can be released to the environment. The overall goal of this research is to develop a better understanding of the processes and conditions controlling the transport and fate of hormones, pharmaceuticals, and personal-care products (HPPCPs) from on-site wastewater treatment systems and the implications for unsewered development.
The proposed research will use controlled laboratory column experiments to investigate how sorption and degradation processes within saturated and unsaturated sediments, the chemical composition of wastewater effluent, and compound-specific properties affect the mobility, and ultimately the fate, of organic compounds in the subsurface. The results of these experiments will be used to design field tracer tests that can be performed through instrumented septic systems at a subdivision site in Dane County, Wisconsin. Finally, relevant parameters including retardation and degradation will be incorporated into groundwater models to simulate contaminant transport beneath unsewered subdivisions with varying layouts, housing densities, septic system type, well designs, and soil and bedrock type to assess the likelihood of unintentional exposure to HPPCPs through nearby drinking water wells or surface water bodies.
This study will contribute an increased knowledge of the processes and conditions controlling the fate and transport of organic contaminants from on-site wastewater treatment systems. The modeling phase of this study is intended to assess the overall impacts of unsewered subdivisions on groundwater supplies and assist decision makers in weighing the alternatives of subdivision development, including site location, lot size, housing density, well design, and septic system design and location.