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Long-Term Water-Quality Constituent Trends in the Little Arkansas River, South-Central Kansas, 1995–2021

Scientific Investigations Report 2023-5102
Prepared in cooperation with the city of Wichita, Kansas
By:  and 
https://doi.org/10.3133/sir20235102

Links

  • Document: Report (5.5 MB pdf) , HTML , XML
  • Tables:
    • Table 2.1 (20 KB xlsx) - Summary statistics for continuously (hourly) measured turbidity data measured with different sensors at the Little Arkansas River at Highway 50 near Halstead, Kansas; Little Arkansas River near Sedgwick, Kans.; and Little Arkansas River upstream of ASR Facility near Sedgwick, Kans., 2004–19
    • Table 2.1 (2.2 KB csv)
    • Table 3.1 (27 KB xlsx) - Relative percentage differences for discrete replicate pairs and detection percentages for blank discrete water-quality samples for the Little Arkansas River sites near Sedgwick, Kansas, 1995–2021
    • Table 3.1 (6.3 KB csv)
    • Tables 7.1–7.3 (108 KB xlsx)
    • Table 7.1 (12 KB csv) - Weighted Regressions on Time, Discharge, and Season estimated mean, flow-normalized, and generalized mean concentrations for primary ions at the Little Arkansas River at Highway 50 near Halstead, Kansas, and Little Arkansas River near Sedgwick, Kans., 1995–2021
    • Table 7.2 (10 KB csv) - Weighted Regressions on Time, Discharge, and Season estimated mean, flow-normalized, and generalized mean concentrations for nutrients and carbon species at the Little Arkansas River at Highway 50 near Halstead, Kansas, and Little Arkansas River near Sedgwick, Kans., 1995–2021
    • Table 7.3 (8 KB csv) - Weighted Regressions on Time, Discharge, and Season estimated mean, flow-normalized, and generalized mean concentrations or densities for sediment, indicator bacteria, and trace elements at the Little Arkansas River at Highway 50 near Halstead, Kansas, and Little Arkansas River near Sedgwick, Kans., 1995–2021
    • Tables 8.1–8.3 (112 KB xlsx)
    • Table 8.1 (12 KB csv) - Weighted Regressions on Time, Discharge, and Season estimated mean, flow-normalized, and generalized mean fluxes for primary ions at the Little Arkansas River at Highway 50 near Halstead, Kansas, and Little Arkansas River near Sedgwick, Kans., 1995–2021
    • Table 8.2 (10 KB csv) - Weighted Regressions on Time, Discharge, and Season estimated mean, flow-normalized, and generalized mean fluxes for nutrients and carbon species at the Little Arkansas River at Highway 50 near Halstead, Kansas, and Little Arkansas River near Sedgwick, Kans., 1995–2021
    • Table 8.3 (9 KB csv) - Weighted Regressions on Time, Discharge, and Season estimated mean, flow-normalized, and generalized mean fluxes for sediment, indicator bacteria, and trace elements at the Little Arkansas River at Highway 50 near Halstead, Kansas, and Little Arkansas River near Sedgwick, Kans., 1995–2021
    • Table 11.1 (51 KB xlsx) - Weighted Regressions on Time, Discharge, and Season estimated yearly water-quality constituent loads at the Little Arkansas River at Highway 50 near Halstead, Kansas and near Sedgwick, Kans., 1998–2021
    • Table 11.1 (14 KB csv)
  • Figure: Figure 1.1 (2.7 MB pdf) - Relations between turbidity sensors, 2004–19. A, YSI 6026 (YSI6026) and YSI 6136 (YSI6136) at the Little Arkansas River at Highway 50 near Halstead, Kansas
  • Appendixes:
    • Appendix 4 (1.1 MB zip) - Surrogate Regression Model Archive Summaries for the Little Arkansas River at Highway 50 near Halstead, Kansas
    • Appendix 5 (2.7 MB zip) - Surrogate Regression Model Archive Summaries for the Little Arkansas River near Sedgwick, Kansas
    • Appendix 6 (2.6 MB zip) - Surrogate Regression Model Archive Summaries for the Little Arkansas River upstream of ASR Facility near Sedgwick, Kansas
    • Appendix 9 (35 MB zip) - Weighted Regressions on Time, Discharge, and Season Graphical Output at station 07143672
    • Appendix 10 (46 MB zip) - Weighted Regressions on Time, Discharge, and Season Graphical Output at station 07144100
  • Dataset: USGS National Water Information System database —USGS water data for the Nation
  • Download citation as: RIS | Dublin Core

Abstract

The Equus Beds aquifer and Cheney Reservoir are primary sources for the city of Wichita’s current (2023) water supply. The Equus Beds aquifer storage and recovery (ASR) project was developed by the city of Wichita in the early 1990s to meet future water demands using the Little Arkansas River as an artificial aquifer recharge water source during above-base-flow conditions. Little Arkansas River water is removed from the river at an ASR Facility intake structure, treated using National Primary Drinking Water Regulations as a guideline, and is infiltrated into the Equus Beds aquifer through recharge basins or injected into the aquifer through recharge wells for later use. The U.S. Geological Survey, in cooperation with the city of Wichita, completed this study to quantify and characterize Little Arkansas River water-quality data. Data in this report can be used to evaluate changing conditions, provide science-based information for decision making, and help meet regulatory requirements.

Continuous (hourly) physicochemical properties were measured, and discrete water-quality samples were collected from three Little Arkansas River sites located along the easternmost extent of the Equus Beds aquifer during 1995 through 2021 over a range of streamflow conditions. The Little Arkansas River at Highway 50 near Halstead, Kansas, streamgage (U.S. Geological Survey station 07143672; hereafter referred to as the “Highway 50 site”) is located upstream from the other two sites, and the Little Arkansas River near Sedgwick, Kans., streamgage (U.S. Geological Survey station 07144100; hereafter referred to as the “Sedgwick site”) is located downstream from the other two sites; these two sites bracket most of the easternmost part of the Equus Beds aquifer. The Little Arkansas River upstream of ASR Facility near Sedgwick, Kans., streamgage (U.S. Geological Survey station 375350097262800; hereafter referred to as the “Upstream ASR site”) is located between the Highway 50 and Sedgwick sites, about 14.7 river miles (mi) downstream from the Highway 50 site, about 1.7 river mi upstream from the Sedgwick site, and immediately upstream from the ASR Facility intake structure. Surrogate models for water-quality constituents of interest (including bromide, dissolved organic carbon, 2-chloro-4-isopropylamino-6-amino-s-triazine [deethylatrazine], atrazine, and metolachlor) were updated or developed using continuously measured and concomitant discrete data. These surrogate models, along with previously developed regression models, were used to compute concentrations (at the Highway 50, Sedgwick, and Upstream ASR sites) and loads (at the Highway 50 and Sedgwick sites) during the study period. Federal criteria were used to evaluate water quality. Where applicable, water-quality data were compared to Federal national drinking-water regulations. Flow-normalized water-quality constituent trends were evaluated using Weighted Regressions on Time, Discharge, and Season (WRTDS) statistical models and water-quality trends were described using WRTDS bootstrap tests.

Continuously computed primary ion concentrations were generally larger at the Highway 50 site compared to the Sedgwick site. During the study period, the Federal secondary maximum contaminant level (SMCL) for dissolved solids was exceeded 57 percent of the time at the Highway 50 site and 38 percent of the time at the Sedgwick site. Computed bromide concentrations were larger at the Highway 50 site and exceeded the city of Wichita treatment threshold about 70, 21, and 19 percent of the time at the Highway 50, Sedgwick, and Upstream ASR sites, respectively. Chloride concentrations exceeded the Federal SMCL about 16 percent of the time at the Highway 50 site and did not exceed the SMCL at the Sedgwick site. Continuous arsenic concentrations exceeded the Federal Maximum Contaminant Level (MCL) 9 to 15 percent of the time at the Sedgwick and Highway 50 sites, respectively, during the study. Atrazine concentrations exceeded the Federal MCL 10 percent of the time at the Highway 50 and Sedgwick sites and 14 percent of the time at the Upstream ASR site during the study; computed glyphosate concentrations at the Sedgwick site never exceeded the MCL during the study.

Little Arkansas River flow-normalized primary ion concentrations during 1995 through 2021 generally had downward trends and decreases were generally larger at the Highway 50 site compared to the Sedgwick site. Dissolved solids and chloride concentrations decreased at the Highway 50 and Sedgwick sites. Bromide had no trend at the Highway 50 site and a downward trend at the Sedgwick site. Nitrate plus nitrite and total phosphorus concentrations had upward trends at the Highway 50 site but downward trends at the Sedgwick site, whereas total organic carbon had upward trends at both sites. Nitrate plus nitrite, total nitrogen, total phosphorus, and total organic carbon fluxes had upward trends at the Highway 50 and Sedgwick sites. Suspended-sediment concentrations had an upward trend at the Highway 50 site and had no trend at the Sedgwick site. Arsenic concentrations had downward trends at the Highway 50 and Sedgwick sites.

About one-quarter to one-half of the Little Arkansas River loads, including nutrients and sediment, were transported during 1 percent of the time during the study. Because streamflows are highly sensitive to climatic variation and an increase of extreme precipitation events in the Great Plains is expected, similar disproportionately large pollutant loading events may increase into the future. Continuous measurement of physicochemical properties in near-real time allowed characterization of Little Arkansas River surface water during conditions and time scales that would not have been possible otherwise and served as a complement to discrete water-quality sampling. Continuation of this water-quality monitoring will provide data to characterize changing conditions in the Little Arkansas River and possibly identify new and changing trends. Information in this report allows the city of Wichita to make informed municipal water-supply decisions using past and present water-quality conditions and trends in the watershed.

Suggested Citation

Stone, M.L., and Klager, B.J., 2023, Long-term water-quality constituent trends in the Little Arkansas River, south-central Kansas, 1995–2021: U.S. Geological Survey Scientific Investigations Report 2023–5102, 103 p., https://doi.org/10.3133/sir20235102.

ISSN: 2328-0328 (online)

Study Area

Table of Contents

  • Acknowledgments
  • Abstract
  • Introduction
  • Methods
  • Little Arkansas River Long-Term Water Quality
  • Summary
  • References Cited
  • Appendix 1. Turbidity Sensor Relations
  • Appendix 2. Turbidity Sensor Comparisons
  • Appendix 3. Quality Assurance and Quality Control Summary
  • Appendix 4. Surrogate Regression Model Archive Summaries for the Little Arkansas River at Highway 50 near Halstead, Kansas (U.S. Geological Survey station 07143672)
  • Appendix 5. Surrogate Regression Model Archive Summaries for the Little Arkansas River near Sedgwick, Kansas (U.S. Geological Survey station 07144100)
  • Appendix 6. Surrogate Regression Model Archive Summaries for the Little Arkansas River upstream of ASR Facility near Sedgwick, Kansas (U.S. Geological Survey station 375350097262800) 
  • Appendix 7. Weighted Regressions on Time, Discharge, and Season Concentrations 
  • Appendix 8. Weighted Regressions on Time, Discharge, and Season Fluxes 
  • Appendix 9. Weighted Regressions on Time, Discharge, and Season Graphical Output at station 07143672 
  • Appendix 10. Weighted Regressions on Time, Discharge, and Season Graphical Output at station 07144100 
  • Appendix 11. Weighted Regressions on Time, Discharge, and Season Estimated Yearly Water-Quality Constituent Loads 
Publication type Report
Publication Subtype USGS Numbered Series
Title Long-term water-quality constituent trends in the Little Arkansas River, south-central Kansas, 1995–2021
Series title Scientific Investigations Report
Series number 2023-5102
DOI 10.3133/sir20235102
Year Published 2023
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Kansas Water Science Center
Description Report: ix, 103 p.; 1 Figure; 9 Tables; 5 Appendixes; Dataset
Country United States
State Kandad
Online Only (Y/N) Y
Additional Online Files (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details