Surrogate Regression Model for Computation of Chloride Concentrations at Station 05427965 Spring Harbor Storm Sewer at Madison, Wisconsin (2014-2024)

In cooperation with the City of Madison and the Madison Metropolitan Sewerage District (MMSD), the U.S. Geological Survey (USGS) has collected discrete storm sewer samples for analysis of chloride concentrations at a real-time streamflow and water-quality monitoring (specific conductance) station located at Spring Harbor Storm Sewer in Madison, Wisconsin (USGS station 05427965). Data were collected from 2014-2024 at this station for the purpose of predicting chloride concentrations using real-time continuous specific conductance data. A piecewise (or segmented; SEG) regression equation was developed by relating discrete chloride samples to continuous specific conductance data. The regression equation included the explanatory variable of continuous specific conductance and the response variable of chloride concentration with base-10 logarithmic (log) transformations. Data files in .CSV format include the variables of datetime (nearest 15-minutes), sample datetime (exact time of sample), specific conductance (microsiemens per centimeter at 25 degrees Celsius, uS/cm), chloride concentrations (milligrams per liter, mg/L), and the log base 10 transformed variables of chloride and specific conductance.