Supporting dataset for chloride source delineation in an urban-agricultural watershed, deicing agents versus agricultural contributions

Authors

Eric Wade Peterson, Illinois State UniversityFollow
Andrew Oberhelman, University of FloridaFollow

Document Type

Data

Publication Date

8-2019

Keywords

Road Salt, Chemical Ratios, Land Use, High Frequency Sampling, Tile Drain, Chloride

Abstract

Analyses (n = 535) of chloride (Cl^-), bromide (Br^-), nitrate as nitrogen (NO₃-N), sodium (Na⁺), calcium (Ca²⁺), and potassium (K⁺) in stream water, tile-drain water, and groundwater were conducted in an urban-agricultural watershed (10% urban/impervious, 87% agriculture) to explore potential differences in the signature of Cl^- originating from an urban source as compared to an agricultural source. Water samples were collected on a weekly interval from February 2018 to February 2019 at three station along the stream and from tile drains and wells. Nearly all surface water and tile water samples had Cl^- concentrations above the calculated background threshold of 18 mg/l. Mann-Whitney U test revealed ratios of Cl^- to Br^- (p = 0.045), NO³-N (p < 0.0001), Ca²⁺ (p < 0.0001), and Na⁺ (p < 0.0001) to be statistically significantly different between urban and agricultural waters. Cl- ratios indicate that road salt is the dominant source of Cl- in the watershed, while potassium chloride fertilizer is an important secondary source. This study demonstrated that while deicing in watersheds where urban land use is minimal can have a profound impact on Cl^- dynamics, agricultural practices should not be ignored.

Recommended Citation

Peterson, Eric Wade and Oberhelman, Andrew, "Supporting dataset for chloride source delineation in an urban-agricultural watershed, deicing agents versus agricultural contributions" (2019). Faculty Publications-- Geography, Geology, and the Environment. 1.
https://ir.library.illinoisstate.edu/fpgeo/1