Baltimore Ecosystem Study Institute of Ecosystem Studies

2010 BES Annual Meeting Presentation and Poster Abstracts

Deployment of Real-time Nitrate and Conductivity Sensors in Dead Run: Logistical Challenges and Practical Solutions
VerHoef, Jason
Co-Authors: Jason VerHoef, Claire Welty, Melissa Grese, William Davies, Julia Miller, Philip Larson, Sujay Kaushal, Larry Band, Jon Duncan, Peter Groffman, Andrew Miller, Michael McGuire, Kenneth Belt, and Reed Maxwell

Abstract: Our goal is to deploy nitrate and electrical conductivity sensors in BES streams to obtain near-real-time solute concentration data. A specific research question we aim to address is how information from high-frequency sensor deployment across a range of hydrologic conditions be used to "fill in the gaps" from current weekly long-term monitoring to explain interannual changes in residence times and flushing of solutes. Satlantic SUNA nitrate sensors and YSI 660 LS temperature/ conductivity sensors were purchased based on successful usage elsewhere. Conductivity is being used as a surrogate for chloride through a laboratory-developed correlation function. Deployment locations were chosen to coincide with USGS stream gaging stations in a nested watershed design. Pilot deployment is being carried out at six Dead Run stations in year 1 and at six BES longitudinal stations in year 2 of the project, for the purpose of evaluating data over a range of scales and across four seasons. The first two sensors were deployed at Dead Run Franklintown in October 2010 and are streaming data to UMBC; the remaining Dead Run sensor stations will become operable later this fall. This presentation will discuss many lessons learned in carrying out the initial deployment. Considerations include laboratory testing for interferences from turbidity and DOC; testing of in-line filtering apparatus; pump selection; power budgeting; equipment and material selection for supports and shelters; data-logger wiring and programming; wireless data communication; and concealment of the apparatus in an urban environment. Data collected to date will be presented.