You are here:
Chloride dynamics in a restored urban stream and the influence of road salts on water quality
Citation:
COOPER, C. A., P. M. MAYER, AND B. R. FAULKNER. Chloride dynamics in a restored urban stream and the influence of road salts on water quality. Presented at 16th Non-point Source Monitoring Workshop, Columbus, OH, September 15, 2008.
Impact/Purpose:
To assess the implications for human health and ecosystem services from the wide use of de-icers.
Description:
Understanding the connection between road salts and water quality is essential to assess the implications for human health and ecosystem services from these widely used de-icers. Preliminary analysis identified a probable connection between road salt application and a stream water quality response in Minebank Run, a first order urban stream in Maryland, USA. Minebank Run was recently restored to stabilize streambanks, at a cost of approximately $4 million. To assess the effects of the restoration on water quality, surface and ground waters have been monitored at Minebank Run since 2001. Stream gauges and piezometers were installed in the stream channel and floodplain of Minebank Run along multiple transects above and below the I-695 Beltway. Initial examination of chloride found elevated concentrations in both the surface and ground waters, often above acceptable drinking water recommendations and reaching concentrations known to injure woody plants. Salinity levels in Minebank Run increase immediately below the I-695 Beltway. Chloride concentrations remain consistently greater in both surface and ground water below the Beltway. Elevated ground water chloride concentrations suggest that ground water may act as a continuous source of chloride to surface water. Ongoing analysis examining the relationship between salt application, storm events and the in-stream response will be completed in July 2008. Additionally, cation exchange in the marble rich parent material of the basin’s soils and trend analysis to determine effects on surface and ground water quality will also be analyzed. The potential for road salt de-icers to impact stream restoration efforts by increasing salinity levels in urbanizing watersheds will be discussed along with the possibility for drinking water impacts.
