Title: Municipal biosolid applications: Improving ecosystem services across urban, agricultural, and wildlife interfaces in Austin, Texas Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 15, 2009
Publication Date: N/A
Technical Abstract: Our project encompasses emerging contaminants, ecosystem services, and urban-agriculture-wildlife interfaces. This seminal research collaboration between USDA-ARS Grassland, Soil, and Water Research Laboratory, The City of Austin Water Utility, and Texas Parks and Wildlife Environmental Contaminants Laboratory. These entities, representing three levels of government, are committed to working together in a series of experiments at the Hornsby Bend Biosolids Management Plant (HBBMP) in Austin, Travis County, Texas. There is no comprehensive overview of a land-based biosolids recycling program at this scale and scope in the literature. We are quantifying the chemical profiles, persistence, and hydrologic transport of biosolids-borne anthropogenic compounds (e.g., hormones, nutrients, micronutrients, trace metals, and organic contaminants) across urban-agriculture-wildlife interfaces from the point of arrival at HBBMP, through land-application, movement in the soil profile, and into groundwater. The data generated in this study provide important baseline data for future risk assessments and studies of anthropogenic compound fate and bioavailability. Low level exposure to anthropogenic compounds may disrupt endocrine systems in humans and wildlife. However, no comprehensive model of organic contaminant migration from land treatment systems has yet been developed. We are quantifying the persistence and transport of anthropogenic compounds in the context of a real-world, full-scale municipal biosolids management program. In a controlled study, we will develop parameters for fate and transport of various contaminants. In a series of soil infiltration experiments, we will manipulate precipitation events on intact soil microcosms excavated from points of varied biosolid land application rates within the HBBMP management landscape. Utilizing the analytical expertise of the U.S. Geological Survey’s National Water Quality Assessment Laboratory (NWQL; Denver, Colorado), Texas Parks and Wildlife Environmental Contaminants Laboratory (ECL; San Marcos, Texas), and analytical facilities at the USDA-ARS Grassland, Soil, and Water Research Laboratory (Temple, Texas), we are quantifying real-world management effects on the persistence and infiltration of anthropogenic compounds commonly found in biosolids. The third novel aspect of our research is development of the USDA-ARS’ Soil and Water Assessment Tool (SWAT) to model the persistence and transport of hormones and organic contaminants at the watershed-scale. We will refine SWAT parameters to model the persistence and movement of biosolids-borne anthropogenic compounds, and then use the model to predict long-term effects of various biosolids management scenarios and climate variability (e.g., variable precipitation) on soil and water transport processes. The model simulations will be validated on long term application sites at HBBMP. There is a need for risk management tools to address the origin, transport, and fate of anthropogenic compounds in the environment. This project will move us forward in providing this risk assessment tool. Results will help The City of Austin Water Utility develop a more ecologically-sound, cost-efficient management plan to enhance the sustainability of its land-based biosolids recycling program. Austin Water Utility’s HBBMP is an exemplary facility, a two-time first place recipient of the US-EPA’s Environmental Excellence Award. Thus, the implications of our research and model development are not confined to managing the local facility, but will serve as decision making tools for national and international biosolids managers.