Using sorbent media to address the impact of deicing salt on contaminant dynamics in infiltration-based green stormwater management: nutrients, metals, and trace organics
Abstract:
Degraded water quality can negatively impact the key waterways of Pennsylvania. For example, excess nutrients can result in development of a Total Maximum Daily Load, metal concentrations can exceed aquatic life criteria particularly in saltwater ecosystems, and trace organic contaminants including poly- and perfluoroalkyl substances (PFAS) are under increased scrutiny due to persistence, toxicity, and bioaccumulation but behave differently than traditional contaminants such as polycyclic aromatic hydrocarbons (PAHs).
This proposal will focus on the four contaminant classes’ retention or transport in infiltration-based stormwater management practices, specifically the impacts of intermittent flow and seasonal deicer salt application and mitigation strategies.
Building on ongoing involvement in regional stormwater monitoring, statistical analysis of historic data will be conducted to evaluate the performance of conventional media (sandy loam) to identify strengths and shortcomings in contaminant removal performance. This work will be extended through laboratory experiments to better understand how the combination of salinity and intermittent flow impacts the fate and transport of the four contaminant classes.
Experimental work is approached with increasing complexity as follows: 1) batch studies to evaluate salt impact on sorption, 2) continuous flow 1-D saturated columns to evaluate salt impact on transport, 3) intermittent flow columns to evaluate contaminant leaching impacted by wetting/drying cycles and salt, and 4) column mesocosm studies testing stochastic salinity and intermittent flow effects on contaminant fate and transport.
The statistical analysis and experimental results will be synthesized to evaluate the performance of conventional media and to identify if sorbent amendments could provide further water quality enhancements. The proposed work is responsive to “Healthy Coastal Ecosystems” and “Resilient Communities and Economies,” to evaluate and improve stormwater management and enhance water resources, and opportunities to engage professional and scholastic audiences have been identified for results dissemination.
