USING ELECTRICAL CONDUCTIVITY MEASUREMENTS AS A STREAM ASSESSMENT TOOL: A CASE STUDY IN WATERSHED EDUCATION AND RESEARCH

As part of a campus-based volunteer monitoring program and field work for an introductory course in environmental engineering, undergraduate students from Lafayette College noted consistently high electronic conductivity (EC) readings in the lower reaches of Bushkill Creek, Northampton County, Pennsylvania. The Delaware River Basin Commission independently identified Bushkill Creek as a source of degradation of the Delaware River, particularly with respect to EC. Although short term spikes in EC could be attributed to road salt, consistently high readings under baseflow conditions warranted further investigation of EC of the Bushkill and other local streams as a research project. Because the area is underlain by soluble carbonate bedrock, high EC values were expected, but the fundamental question of "How high is too high?" still remained. To answer this question, we developed a screening method that uses concurrent alkalinity data as an index of bedrock type to normalize the EC values and thus distinguish background EC values from those indicative of anthropogenic impacts. This paper discusses this project as a case study in watershed education and research.