2 July 2007 Morehart Farm Dye Trace

Abstract

Our research is designed to delineate springsheds feeding trout streams in Olmsted County, Minnesota. Trout streams are highly dependent on springs discharging large volumes of cool, clear spring water in order to sustain trout populations. Olmsted County is an area of Southeastern Minnesota with mature karst, and as such, the surficial bedrock aquifer is highly vulnerable to pollution and contamination. In particular, highly turbid ground water from storm events can reach springs and thereby adversely affecting trout populations. Fluorescent dye tracing was utilized to delineate springshed areas and conduit connections of springs feeding the east side of Kinney Creek in Pleasant Grove and Orion Townships. In late June 2007, background monitoring was started at selected locations and on 2 July 2007 a double dye trace was initiated by introducing the fluorescent dyes eosin (CAS 17372-87-1) and sulforhodamine B (CAS 3520-42-1) to sinkholes MN55:D0133 and MN55:D0162, respectively. Direct water . samples and activated carbon detectors were analyzed by scanning spectrofluorometric methods revealing both introduction points to be in the springshed McConnell's Spring (MN55:A0006). Travel times were faster than three days per kilometer.