Prepared in cooperation with the City of Fayetteville, Arkansas, and Beaver Water District

Ambient Conditions and Fate and Transport Simulations of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

Scientific Investigations Report 2013–5019

U.S. Department of the Interior U.S. Geological Survey Cover: Photo by Robert Morgan, Beaver Water District. Ambient Conditions and Fate and Transport Simulations of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

By W. Reed Green

Prepared in cooperation with the City of Fayetteville, Arkansas, and Beaver Water District

Scientific Investigations Report 2013–5019

U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2013

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Suggested citation: Green, W. Reed, 2013, Ambient conditions and fate and transport simulations of dissolved solids, chloride, and sulfate in Beaver Lake, Arkansas, 2006–10: U.S. Geological Survey Scientific Investigations Report 2013–5019, 50 p. iii

Contents

Abstract...... 1 Introduction...... 1 Purpose and Scope...... 2 Description of Study Area...... 2 Methods...... 2 Streamflow...... 2 Water-Quality Sampling...... 2 Constituent Loads...... 4 Data Analysis...... 5 Model Implementation...... 5 Computational Grid...... 5 Boundary and Initial Conditions...... 5 Hydraulic and Thermal Boundary Conditions...... 5 Dissolved Solids, Chloride, and Sulfate Boundary Conditions...... 7 Initial Conditions...... 7 Model Parameters...... 7 Model Calibration and Testing...... 7 Water Balance...... 8 Sensitivity Analysis...... 8 Model Limitations...... 9 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake...... 9 Hydrologic Conditions...... 9 Water-Quality Conditions...... 9 Inflow Water Quality...... 11 Reservoir Water Quality...... 11 Dissolved Solids, Chloride, and Sulfate Fate and Transport Simulations ...... 14 Inflow Loads and Concentrations...... 14 Reservoir Hydrodynamics...... 14 Dissolved Solids, Chloride, and Sulfate Concentrations...... 14 Dissolved Solids, Chloride, and Sulfate Fate and Transport...... 18 Summary...... 49 Cited References...... 49 iv

Figures

1. Map showing Beaver Lake study area, Arkansas, with locations of water-quality sampling sites...... 3 2. Composite showing side view (A), top view (B), and face view from the dam (C) of the computational grid of Beaver Lake, Arkansas, used in the CE-QUAL-W2 model...... 6 Graphs showing: 3. Simulated and measured water-surface elevations near Beaver Lake dam, Arkansas, January 2006 through December 2010...... 8 4. Mean daily streamflow for White River (site S1), Richland Creek (site S2), and War Eagle Creek (site S3), and hourly outflow at Beaver Lake dam...... 10 5. Distribution of dissolved solids, chloride, and sulfate concentrations for White River (site S1), Richland Creek (site S2), and War Eagle Creek (site S3), 2006–10...... 12 6. Distribution of dissolved solids, chloride, and sulfate concentrations 2 meters (m) below the surface at lake sites L1–L5, L9, and L10, 2006–10...... 13 7. Time-series distributions of measured and S-LOADEST estimated dissolved solids, chloride, and sulfate concentrations at White River (site S1)...... 15 8. Time-series distributions of measured and S-LOADEST estimated dissolved solids, chloride, and sulfate concentrations at Richland Creek (site S2)...... 16 9. Time-series distributions of measured and S-LOADEST estimated dissolved solids, chloride, and sulfate concentrations at War Eagle Creek (site S3)...... 17 10. Selected simulated and measured water-temperature profiles for Beaver Lake at Highway 412 bridge near Eureka Springs, Arkansas (site L5, segment 35)...... 19 11. Simulated and measured dissolved solids concentrations 2 meters below the surface in Beaver Lake, Arkansas...... 22 12. Simulated and measured dissolved solids concentrations 2 meters above the bottom in Beaver Lake, Arkansas...... 24 13. Simulated and measured chloride concentrations 2 meters below the surface in Beaver Lake, Arkansas...... 26 14. Simulated and measured chloride concentrations 2 meters above the bottom in Beaver Lake, Arkansas...... 28 15. Simulated and measured sulfate concentrations 2 meters below the surface in Beaver Lake, Arkansas...... 30 16. Simulated and measured sulfate concentrations 2 meters above the bottom in Beaver Lake, Arkansas...... 32 17. Dissolved solids, chloride, and sulfate concentrations 2 meters below the surface at model segments 2, 5, 48, 14, 16, 23 and 35 from baseline model and increased loading scenarios from both White River near Fayetteville, Arkansas, (site S1) and War Eagle Creek near Hindsville, Ark. (site S3)...... 34 18. Average daily dissolved solids for the period January 2006 through December 2010 from White River near Fayetteville, Arkansas, (site S1) only...... 40 v

19. Average daily dissolved solids for the period January 2006 through December 2010 from War Eagle Creek near Hindsville, Arkansas, (site S3) only ...... 41 20. Average daily dissolved solids for the period January 2006 through December 2010 from both White River near Fayetteville, Arkansas, (site S1) and War Eagle Creek near Hindsville, Ark. (site S3)...... 42 21. Average daily chloride concentrations for the period January 2006 through December 2010 from White River near Fayetteville, Arkansas, (site S1) only ...... 43 22. Average daily chloride concentrations for the period January 2006 through December 2010 from War Eagle Creek near Hindsville, Arkansas, (site S3) only ...... 44 23. Average daily chloride concentrations for the period January 2006 through December 2010 from both White River near Fayetteville, Arkansas, (site S1) and War Eagle Creek near Hindsville, Ark. (site S3)...... 45 24. Average daily sulfate concentrations for the period January 2006 through December 2010 from White River near Fayetteville, Arkansas, (site S1) only ...... 46 25. Average daily sulfate concentrations for the period January 2006 through December 2010 from War Eagle Creek near Hindsville, Arkansas, (site S3) only ...... 47 26. Average daily sulfate concentrations for the period January 2006 through December 2010 from both White River near Fayetteville, Arkansas, (site S1) and War Eagle Creek near Hindsville, Ark. (site S3) ...... 48

Tables

1. Streamflow and water-quality sites for Beaver Lake, Arkansas...... 4 2. Parameters and values used in the CE-QUAL-W2 model of Beaver Lake, January 2006 to December 2010...... 7 3. Statistics measuring error between measured and S-LOADEST estimated dissolved solids, chloride, and sulfate concentrations at White River (S1), Richland Creek (S2), and War Eagle Creek (S3)...... 18 4. CE-QUAL-W2 model calibration evaluation statistics for water temperature, dissolved solids, chloride, and sulfate for Beaver Lake sites, January 2006 through December 2010...... 20 5. Average daily dissolved solids, chloride, and sulfate concentrations for baseline condition and increasing loading factor scenarios from White River near Fayetteville (site S1) only, for the period January 2006 through December 2010...... 37 6. Average daily dissolved solids, chloride, and sulfate concentrations for baseline condition and increasing loading scenarios from War Eagle Creek (site S3) only, for the period January 2006 through December 2010...... 38 7. Average daily dissolved solids, chloride, and sulfate concentrations for baseline condition and increasing loading factor scenarios from White River near Fayetteville (site S1) and War Eagle Creek near Hindsville (site S3), for the period January 2006 through December 2010...... 39 vi

Conversion Factors

SI to Inch/Pound

Multiply By To obtain Length centimeter (cm) 0.3937 inch (in.) millimeter (mm) 0.03937 inch (in.) meter (m) 3.281 foot (ft) kilometer (km) 0.6214 mile (mi) kilometer (km) 0.5400 mile, nautical (nmi) meter (m) 1.094 yard (yd) Area square kilometer (km2) 247.1 acre Volume cubic meter (m3) 6.290 barrel (petroleum, 1 barrel = 42 gal) liter (L) 33.82 ounce, fluid (fl. oz) liter (L) 2.113 pint (pt) liter (L) 1.057 quart (qt) liter (L) 0.2642 gallon (gal) cubic meter (m3) 0.0002642 million gallons (Mgal) liter (L) 61.02 cubic inch (in3) cubic meter (m3) 35.31 cubic foot (ft3) cubic meter (m3) 1.308 cubic yard (yd3) Flow rate cubic meter per second (m3/s) 70.07 acre-foot per day (acre-ft/d) Mass gram (g) 0.03527 ounce, avoirdupois (oz) kilogram (kg) 2.205 pound avoirdupois (lb)

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows: °F=(1.8×°C)+32 Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 (NGVD 1929) Altitude, as used in this report, refers to distance above the vertical datum. Ambient Conditions and Fate and Transport Simulations of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

By W. Reed Green

Abstract concentration scenarios. The results for both the 2 m below the surface and 2 m above the bottom were similar, with the Beaver Lake is a large, deep-storage reservoir located exception of concentrations resulting from the increased in the upper White River Basin in northwestern Arkansas, loading factors (5.0 and 10.0 times), where concentrations and was completed in 1963 for the purposes of flood control, 2 m above the bottom were consistently greater than those hydroelectric power, and water supply. Beaver Lake is affected 2 m below the surface at most segments. by point and nonpoint sources of minerals, nutrients, and sediments. The City of Fayetteville discharges about half of its sewage effluent into the White River immediately upstream Introduction from the backwater of the reservoir. The City of West Fork discharges its sewage effluent into the West Fork of the White Beaver Lake is a large, deep-storage reservoir located in River, and the City of Huntsville discharges its sewage effluent the upper White River Basin in northwestern Arkansas. The into a tributary of War Eagle Creek. reservoir was completed in 1963 for the purposes of flood A study was conducted to describe the ambient conditions control, hydroelectric power, and water supply. In addition, the and fate and transport of dissolved solids, chloride, and sulfate reservoir is used for fish and wildlife habitat, recreation, and concentrations in Beaver Lake. Dissolved solids, chloride, and waste assimilation. sulfate are components of wastewater discharged into Beaver Beaver Lake is affected by point and nonpoint sources Lake and a major concern of the drinking water utilities that of minerals, nutrients, and sediments. The City of Fayetteville use Beaver Lake as their source. A two-dimensional model discharges about half of its sewage effluent into the White of hydrodynamics and water quality was calibrated to include River immediately upstream from the backwater of the simulations of dissolved solids, chloride, and sulfate for the reservoir. The City of West Fork discharges its sewage period January 2006 through December 2010. Estimated daily effluent into the West Fork of the White River, and the City dissolved solids, chloride, and sulfate loads were increased in of Huntsville discharges its sewage effluent into a tributary the White River and War Eagle Creek tributaries, individually of War Eagle Creek. Water-quality constituents like dissolved and the two tributaries together, by 1.2, 1.5, 2.0, 5.0, and 10.0 solids (DS), chloride (Cl), sulfate (SO4), nutrients, sediment, times the baseline conditions to examine fate and transport of pathogenic bacteria, and others enter Beaver Lake through its these constituents through time at seven locations (segments) tributaries and around its shoreline and through precipitation in the reservoir, from upstream to downstream in Beaver Lake. on the pool. Fifteen dissolved solids, chloride, and sulfate fate and In 2006, a study was conducted by Galloway and Green transport scenarios were compared to the baseline simulation (2006) that analyzed ambient water-quality conditions. at each of the seven downstream locations in the reservoir, In Galloway and Green (2006), a two-dimensional model both 2 meters (m) below the surface and 2 m above the of hydrodynamics and water-quality characteristics was bottom. Concentrations were greater in the reservoir at model developed and calibrated for the period 2001 through 2003. segments closer to where the tributaries entered the reservoir. For the present study, conducted by the U.S. Geological Concentrations resulting from the increase in loading became Survey (USGS) in cooperation with the City of Fayetteville more diluted farther downstream from the source. Differences and Beaver Water District (BWD), their model was modified in concentrations between the baseline condition and the and recalibrated to examine ambient conditions of DS, Cl, and

1.2, 1.5, and 2.0 times baseline concentration scenarios were SO4 and fate and transport of these compounds and elements smaller than the differences in the 5.0 and 10.0 times baseline in Beaver Lake from January 2006 through December 2010. 2 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

Purpose and Scope and water-quality samples were collected at three tributaries to Beaver Lake from January 2006 through December

The purpose of this report is to describe the ambient 2010. Annual DS, Cl, and SO4 loads were estimated from conditions and fate and transport of DS, Cl, and SO4 streamflow and water-quality data at these three sites. Water- concentrations in Beaver Lake. DS, Cl, and SO4 are quality samples were also collected at seven fixed sites components of wastewater discharged into Beaver Lake and a along the downstream gradient in the reservoir during the major concern of the drinking water utilities that use Beaver same time period. Lake as their source. A previously developed CE-QUAL-W2 two-dimensional model of hydrodynamics and water quality in Beaver Lake (Galloway and Green, 2006) was modified Streamflow and recalibrated to include simulations of DS, Cl, and SO4 for the period of January 2006 through December 2010. Stream stage was measured continuously at White River near Fayetteville (site S1), Richland Creek at Goshen (site Estimated daily DS, Cl, and SO4 loads were increased in the White River and War Eagle Creek tributaries, individually S2), and War Eagle Creek near Hindsville (site S3) (table 1 and the two tributaries together, by 1.2, 1.5, 2.0, 5.0, and 10.0 and fig. 1). Stage and instantaneous discharge were measured times the baseline conditions to examine fate and transport to compute the continuous streamflow from stage-discharge of these constituents through time at seven locations in the rating curves by using methods described by Rantz and others reservoir, from upstream to downstream in Beaver Lake. (1982). Outflow data from Beaver Lake were provided by the U.S. Army Corps of Engineers (USACE), Little Rock District, for the period January 2006 through December 2010. Description of Study Area

Beaver Lake (fig. 1) was impounded in 1963 on the Water-Quality Sampling White River, is located northeast of the City of Fayetteville, Ark., and near Eureka Springs, Ark., and had reached Water-quality data were collected from January conservation capacity in 1968 (Haggard and Green, 2002). 2006 through December 2010 at five fixed sites along the The conservation capacity of the reservoir is the storage downstream gradient of Beaver Lake. Sample sites in the capacity used for hydroelectric power, water supply, fish lake were located along the original stream channel, the and wildlife habitat, and recreation (U.S. Army Corps of deepest location within the lake cross section. Samples were Engineers, 1997). The main inflows into Beaver Lake are collected six times annually at White River at Goshen (site the White River, Richland Creek, and War Eagle Creek (fig. L1), at Beaver Lake at Highway 412 bridge near Sonora 1). Several smaller tributaries also flow into the reservoir. (site L2), near Beaver Lake near Lowell (site L3), at Beaver The reservoir has a drainage area of 3,087 square kilometers Lake at Highway 12 bridge near Rogers (site L4), and (km2) at the Beaver Lake dam. Beaver Lake contains 2,040 Beaver Lake near Eureka Springs (site L5) (table 1 and million cubic meters (m3) of water at the top of the current fig.1). Samples were collected six times annually at War conservation pool (341.4 meters (m) above NGVD of 1929) Eagle Creek above White River near Lowell (site L9) from and the surface area is 114 km2 (Haggard and Green, 2002). October 2007 through December 2010 and monthly (12 times The length of the reservoir is 80 kilometers (km) from the annually) at Beaver Lake downstream from Hickory Creek White River at the Highway 45 bridge to the Beaver Lake landing near Springdale (site L10) from August 2008 through dam. The depth of the reservoir at the dam at conservation December 2010. pool elevation is 60 m, and the average depth throughout the Water-quality samples were collected at lake sites by reservoir is 18 m (Haggard and Green, 2002). using a peristaltic pump and weighted hose to collect samples The USGS in cooperation with BWD has monitored 2 m below the water surface when isothermal and well-mixed water quality in Beaver Lake since 2001. Currently, water- conditions were present. During thermal stratification, samples quality samples are collected at seven lake sites (L1–L5, were collected at 2 m below the water surface to represent the L9, and L10) and three tributary inflow sites (S1–S3) (table epilimnion (near surface), at various depths in the metalimnion 1, fig. ).1 Continuous streamflow data are also collected (middle depth) depending on the depth of the thermocline, at S1, S2, and S3 and used to calculate constituent loading and at 2 m above the reservoir bottom to represent the into Beaver Lake. hypolimnion (near bottom). Water-quality samples were analyzed for concentrations of DS (analytically determined by weighing residue after drying at 180 degrees Celsius (°C), not

Methods the sum of individual constituents), Cl, and SO4. All sample analyses were conducted at the USGS National Water Quality This section describes the methods of data collection Laboratory according to USGS procedures (Fishman, 1993). and analysis used to describe the ambient DS, Cl, and SO4 Field measurements of water temperature were also recorded conditions in Beaver Lake used in this report. Streamflow at various depths at the time of sample collection. Methods 3

94°12’ 93°36’

BENTON

62 # 07049690 Eureka (L5, MS35) Springs

Berryville e iri CARROLL

ra 23 P k BEAVER LAKE

Rogers ree C # 07049500 (L4, MS23)

36°18’

# 07049200# (L3, MS16) 07049187 (L10, MS14)

Lowell 12 # 07049160 (L9, MS48) War #07049000 (S3)

Springdale

Eagle Sonora # 412 07048910 (L2, MS5) Hindsville C re 45 ek

07048700 Goshen Fayetteville # (L1, MS2) # 07048800 (S2) Huntsville 07048600 (S1) White R ic hla Fork nd Creek

36°00’ River

Beaver Lake West Basin West Fork

WASHINGTON MADISON

Base from U.S. Geological Survey digital data, 1:100,000 0 2.5 5 MILES

EXPLANATION 0 2.5 5 KILOMETERS

07049000 # Streamflow and water-quality measurement site with associated

ARKANSAS USGS station and stream site identification numbers 07048910 # Lake water-quality measurement site with associated USGS station, lake site, and model grid segment identification numbers

S1 Stream site identification number Location Map L1 Lake site identification number

MS14 Model grid segment number

Figure 1. Beaver Lake study area, Arkansas, with locations of water-quality sampling sites. 4 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

Table 1. Streamflow and water-quality sites for Beaver Lake, Arkansas Site U.S. Geological Model grid Latitude Longitude identification Survey station segment Station name Station type (degree,minute, (degree, minute, number (fig. 1) number (fig. 2) second) second) S1 07048600 — White River near Fayetteville Streamflow, 36°04′23″ 94°04′52″ water quality S2 07048800 — Richland Creek at Goshen Streamflow, 36°06′15″ 94°00′28″ water quality S3 07049000 — War Eagle Creek Streamflow, 36°12′00″ 93°51′18″ near Hindsville water quality L1 07048700 2 White River near Goshen Water quality 36°06′21″ 94°00′41″ L2 07048910 5 Beaver Lake at Highway 412 Water quality 36°10′00″ 94°00′26″ bridge near Sonora L3 07049200 16 Beaver Lake near Lowell Water quality 36°15′33″ 94°04′08″ L4 07049500 23 Beaver Lake at Highway 12 Water quality 36°19′56″ 94°01′08″ bridge near Rogers L5 07049690 35 Beaver Lake near Eureka Water quality 36°25′15″ 93°50′50″ Springs L9 07049160 48 War Eagle Creek above White Water quality 36°13′24″ 94°00′38″ River near Lowell L10 07049187 14 Beaver Lake downstream Water quality 36°15′01″ 94°01′35″ from Hickory Creek landing near Springdale

Water-quality samples also were collected from three of the residuals (Cohn, 1995). The regression method uses fixed inflow sites: White River near Fayetteville (site S1), discrete water-quality samples often collected over several Richland Creek at Goshen (site S2), and War Eagle Creek years and a daily streamflow hydrograph. The relations near Hindsville (site S3) (table 1, fig. 1). Water-quality between natural logarithmic-transformed L (QC) and Q were samples were collected following equal-width increment used: methods by using depth-integrated samplers and processed by using protocols described in Wilde and Radke (1998) and ln ()Ll=+ββ nQ() (1) Wilde and others (1998a, 1998b, 1998c, 1999a, and 1999b). 01 Water-quality samples were analyzed for concentrations where of DS, Cl, and SO . Field measurements including water 4 ln is natural logarithm; temperature were collected with each sample. Water-quality L is constituent load, in kilograms per day samples were collected six times annually and during selected (kg/d); surface-runoff events. b o is regression constant, dimensionless; b 1 is a regression coefficient, dimensionless; and Constituent Loads Q is daily streamflow, in cubic meters per second (m3/s). DS, Cl, and SO4 loads were estimated for the three main inflows to Beaver Lake: the White River near Fayetteville (site Transformation of the results of the model from S1), Richland Creek at Goshen (site S2), and War Eagle Creek logarithmic space to real space was accomplished by using near Hindsville (site S3) (fig. 1). Constituent load L( ) is a two methods: an adjusted maximum likelihood estimator function of the volumetric rate of water passing a point in the stream (Q) and the constituent concentration within the water (AMLE) and a least absolute deviation (LAD) (Cohn and (C). Regression methods used to estimate constituent loads use others, 1992). The AMLE method was used if the constituent the natural logarithm (ln) transformed relation between Q and had censored values, and the LAD method was used to C to estimate daily load (L) of the constituent. The regression transform the results if no censored values were included method can account for nonnormal data distributions, seasonal in the data or if outliers in the residuals were present. The and long-term cycles, censored data, biases associated with S-LOADEST computer program (Runkel and others, 2004) using logarithmic transformations, and serial correlations was used to estimate daily loads for 2006 through 2010. Methods 5

Data Analysis Beaver Lake for calendar years 1994 and 1995. Thirty-five computational segments exist along the main stem branch of The resulting measured streamflow, water-quality (DS, the White River and 12 computational segments are in War

Cl, and SO4 concentrations—inflow and lake samples), and Eagle Creek branch in Beaver Lake. In addition, four other S-LOADEST loading rates were analyzed and summarized downstream branches are modeled with three computational by using several graphical techniques for data collected from segments each. Volumes of the smaller embayments not January 2006 through December 2010. Time-series plots were included in the computational grid were added to associated used to describe inflow and outflow. Boxplots and time-series main stem segments so that reservoir volume was preserved. plots were used to compare concentrations of DS, Cl, and SO4 Each segment was divided vertically into 1-m layers. among sites. Boxplots, scatter plots, line plots, and bar charts Tributaries were linked geometrically to the segment they were used to describe model simulation results. enter and allow for the application of inflow without affecting the geometry. Two tributaries were included in the model at the most upstream segment. One tributary was used to Model Implementation simulate the discharge from the Fayetteville wastewater- treatment plant (WWTP) at the upstream segment although A two-dimensional, laterally averaged, hydrodynamic WWTP discharge concentrations were not included for the and water-quality model using CE-QUAL-W2 Version 3.1 purposes of this study; DS, Cl and SO concentration data (Cole and Wells, 2003) had been developed for Beaver Lake 4 in WWTP discharge were limited and uncertain. A second and calibrated on the basis of vertical profiles of temperature tributary was used to simulate the inflow from Richland Creek, and dissolved oxygen, and water-quality constituent and a third to simulate the inflow from Prairie Creek (fig. 1). concentrations were collected at various depths at four sites Model grid segments 2, 5, 14, 16, 23, 35, and 48 (fig. 2) relate in the reservoir from April 2001 to April 2003 (Galloway to water-quality monitoring sites L1, L2, L10, L3, L4, L5, and and Green, 2006). This Beaver Lake CE-QUAL-W2 model L9, respectively (table 1). had simulated water-surface elevation and vertical and longitudinal gradients in water-quality constituents. The model had included routines for 18 state variables in addition Boundary and Initial Conditions to temperature and dissolved oxygen, including any number of inorganic suspended solids groups, phytoplankton groups, nitrogen and phosphorus species, dissolved and particulate Hydraulic and Thermal Boundary Conditions organic matter, total inorganic carbon, and organic sediment. Daily reservoir inflow data (upstream hydraulic Additionally, CE-QUAL-W2 had the capability of computing boundaries) used in the model were obtained from streamflow- more than 60 derived variables from the state variables (Cole gaging station data on the three main inflows (White River, and Wells, 2003); however, for the purposes of this report, Richland Creek, and War Eagle Creek) and were estimated for only water temperature, DS, Cl, and SO were simulated. DS, 4 the three smaller ungaged branches and the tributary, Prairie Cl, and SO were considered to be conservative constituents 4 Creek. The mean daily streamflow recorded for War Eagle and changed concentration only through advection and Creek near Hindsville (site S3, upstream from L9) was used dilution, as a conservative tracer might be expected to behave. to estimate the streamflow for the three ungaged branches Implementation of the CE-QUAL-W2 model for and tributary, based on the ratio between the drainage area for Beaver Lake included development of the computational War Eagle Creek at site S3 and the drainage areas of the three grid, specification of boundary and initial conditions, and ungaged branches and tributary. preliminary selection of model parameter values. Model The downstream hydraulic boundary for the Beaver development and associated assumptions in the selection Lake model consisted of the outflow from Beaver Lake dam. of boundary and initial conditions are described and model The USACE produced hourly outflow data by using stage- parameters are listed in the “Boundary and Initial Conditions” discharge relations and hourly power generation records for and “Model Parameters” sections. the period of January 2006 through December 2010 (U.S. Army Corps of Engineers, written commun., 2011). The Computational Grid release structure (penstock) was simulated as a point release, and the middle of the penstock was located at an elevation of The computational grid used by Galloway and Green 302.2 m above NGVD of 1929, model layer 45 (fig. 2). (2006) and used in this study provides the geometric scheme Hydraulic boundary conditions also included water that numerically represents the space and volume of Beaver withdrawal by four public water-supply districts (Beaver Lake. The grid extends 80 km from the upstream boundary Water District, Carroll-Boone County Water District, Madison (White River at the Highway 45 bridge) to the Beaver Lake County Water District, and Benton-Washington County Water dam (figs. 1 and 2). The grid originally was developed by District). Annualized mean daily withdrawal rates for each Haggard and Green (2002) to simulate the hydrodynamics water-supply district were applied (Terrance W. Holland, U.S. and distribution of temperature and dissolved oxygen in Geological Survey, written commun., 2011). 6 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

A

2

10

20 Model layers Model

30

40

50 Elevation, in metersabove NGVD of 1929

60

Distance from dam, in kilometers 35 B

C

Prairie Creek

23

16 14 k 48 e re C Wa Penstock r gle Ea

5

Fayetteville wastewater- Richland Creek treatment 2 plant discharge

Figure 2. Side view (A), top view (B), and face view from the dam (C) of the computational grid of Beaver Lake, Arkansas, used in the CE-QUAL-W2 model. Methods 7

Hydraulic boundary conditions at the water surface Model Parameters included evaporation, wind stress, and surface heat exchange. Meteorological data required for these computations were Parameters are used to describe the physical and chemical measured hourly at a weather station southwest of Rogers (fig. processes that are not explicitly modeled and to provide 1) (National Climatic Data Center, Asheville, North Carolina, the chemical kinetic rate information. Many parameters written commun., 2011). cannot be measured directly and often are adjusted during Hourly inflow water temperatures were estimated from the model calibration process until simulated values, for air temperature in the meteorological data by using the example, water temperature, dissolved oxygen, and others, Marciano and Harbeck (1954) method and from periodic agree with measured observations. Most of the hydrodynamic measurements at the three main inflow sites (White River, and thermal processes are modeled in CE-QUAL-W2, Richland Creek, and War Eagle Creek). Water temperatures for which results in very few adjustable hydraulic and thermal the three smaller branches and Prairie Creek were estimated parameters. There are many chemical and biological rate only from air temperature. coefficients required for the application of CE-QUAL-W2, which were all temporally constant (table 2). Many of the Dissolved Solids, Chloride, and Sulfate coefficients were based on suggested values given as default Boundary Conditions values for CE-QUAL-W2, and others were based on other Chemical boundary conditions were estimated daily, by model applications (Bales and others, 2001; Haggard and dividing daily S-LOADEST loads (kg/d) by the daily mean Green, 2002; Galloway and Green, 2002 and 2003; Green and streamflow (m3/s) to provide a daily mean concentration others, 2003; Sullivan and Rounds, 2005). (mg/L) for each of the main inflow sites. Daily mean streamflow was used to calculate daily mean concentrations Model Calibration and Testing from daily S-LOADEST loads because it probably more accurately reflected the variation in constituent concentrations Successful model application requires model calibration compared to using discrete concentrations as input, where that includes comparing simulated results with measured the model linearly interpolates daily concentrations between reservoir conditions. The Beaver Lake model calibration sample collection dates. was completed by adjusting parameters for the 5-year period from January 2006 through December 2010. Calibration was Initial Conditions achieved generally by calibrating the water balance first and Initial water-surface elevation, water temperature, and then the thermodynamics. Two statistics were used to compare simulated DS, Cl, and SO4 concentrations for each model segment are required at the start of a model simulation. Initial water- and measured water temperature and DS, Cl, and SO4 surface elevations were set to the measured value (337.0 concentrations. The absolute mean error (AME) indicated the m above NGVD of 1929) on January 1, 2006. At this time, average difference between simulated and measured values Beaver Lake was assumed to be in isothermal conditions and was computed by equation 2: throughout the entire reservoir with an initial water temperature of 6 °C. Initial DS, Cl, and SO concentrations 4 Σ simulatedvalue − measured value also were assumed to be uniform and were set at 80, 4.0, and AME = (2) 9.0 mg/L, respectively. numberof observations

Table 2. Parameters and values used in the CE-QUAL-W2 model of Beaver Lake, January 2006 to December 2010. Parameter description Values Units Coefficient of bottom heat exchange 0.3 watts/square meter/ second Sediment temperature 20.0 degrees Celsius Wind-sheltering coefficient 0.7 dimensionless Horizontal eddy viscosity 1.0 square meters /second Horizontal eddy diffusivity 1.0 square meters/second Light extinction coefficient for pure water 0.35 1/meter Fraction of incident solar radiation absorbed at water surface 0.32 dimensionless 8 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

An AME of 1.5 °C, for example, means that the average correcting the distributed inflow, the temperature and water difference between simulated temperatures and measured quality could be calibrated without the uncertainty incurred temperature is 1.5 °C. with having differences between simulated and measured The root mean square error (RMSE) indicated the spread water-surface elevations. of how far simulated values deviated from the measured values and was computed by equation 3: Sensitivity Analysis A sensitivity analysis is the determination of the effects Σ ()simulatedvalue − measured value 2 RMSE = (3) of small changes in the calibrated model parameters and numberof observations input on model results. A complete sensitivity analysis for the Beaver Lake model was not conducted. Testing of how An RMSE of 1.5 °C, for example, means that the changes in different parameters affect the hydrodynamics, simulated temperatures are within 1.5 °C of the measured temperature, and water quality, however, was conducted as temperatures about 67 percent of the time. part of the model development and calibration. Results from the model development and calibration runs plus information Water Balance from previous model studies (Bales and others, 2001; Simulated water-surface elevations in Beaver Lake were Haggard and Green, 2002; Galloway and Green, 2002, 2003; adjusted to the measured water-surface elevation near the dam Green and others, 2003; Sullivan and Rounds, 2005) were for the model period of January 2006 through December 2010 used to identify several parameters for partial evaluation in (fig. 3). The simulated water-surface elevations were corrected the sensitivity analysis. to the measured values by adjusting the unmeasured inflow The sensitivity of simulated water temperature and into the lake that had been distributed to all the segments water quality was assessed with changes in the wind- within a branch. Inflow was added or subtracted so that the sheltering coefficient and light-extinction coefficient (for simulated water-surface elevation reflected the measured pure water). Simulated vertical profiles of water temperature, water-surface elevation, therefore accounting for unmeasured at 1-m depth intervals, were compared with measured inflow and groundwater interaction in Beaver Lake. By water-temperature profiles.

346

344

342

340

338 EXPLANATION Water-surface elevation,Water-surface meters in above National Geodetic Vertical Datum of 1929 Measured elevation Simulated elevation

336 7/1/2010 1/1/2011 1/1/2010 1/1/2006 7/1/2006 1/1/2007 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009

Date

Figure 3. Simulated and measured water-surface elevations near Beaver Lake dam, Arkansas, January 2006 through December 2010. Ambient Conditions of Dissolved Solids, Chloride, and Sulfate inBeaver Lake 9

Water temperature in the Beaver Lake model was the Hydrologic Conditions most sensitive to wind speed (wind-sheltering coefficient, table 2). The wind speed, adjusted by using the wind- Streamflow varied substantially from January 2006 sheltering coefficient, affects the amount of mixing in the through December 2010 for the three major tributaries that reservoir, which can change the depth of the thermocline and provide inflow to Beaver Lake (fig. 4). The White River is increase or decrease the evaporative cooling. the main inflow into Beaver Lake, and approximately 34

Sensitivity analysis of DS, Cl, and SO4 was not percent of the drainage area at Beaver Lake dam is above the conducted. These water-quality constituents were considered streamflow-gaging station near Fayetteville (site S1, fig. 1). conservative and only changed concentration through The daily mean streamflow for the White River ranged from advection and dilution, as a conservative tracer might be 0.01 to 1,215 m3/s for the period of January 2006 through expected to behave. December 2010. Mean daily streamflow for the period was 16.3 m3/s. The drainage area of Richland Creek above the Model Limitations gaging station at Goshen (site S2, fig. 1) composes 12 percent of the drainage area at Beaver Lake dam. The daily mean The accuracy of the Beaver Lake model was limited by streamflow for Richland Creek ranged from 0.003 to 957 3m /s the simplification of the complexities of the hydrodynamics for the period of January 2006 through December 2010, with a within the reservoir, by spatial and temporal discretization mean daily streamflow of 6.06 3m /s for the period. War Eagle effects, and by assumptions made in the formulation of the Creek at the gaging station near Hindsville (site S3, fig. 1) governing equations. Model accuracy also was limited by has a drainage area that composes 22 percent of the drainage segment size, boundary conditions, accuracy of calibration, area at Beaver Lake dam. The daily mean streamflow for War and parameter sensitivity. Moreover, model accuracy was Eagle Creek ranged from 0.312 to 767 m3/s for the period limited by the availability of data and by the interpolations of January 2006 through December 2010, with a mean daily and extrapolations that were inherent in using data in a model. streamflow of 9.90 3m /s for the period. Although a model might be calibrated, calibration parameter The outflow from Beaver Lake also varied substantially values are generally not necessarily unique in yielding for the period of January 2006 through December 2010 (fig. acceptable values for the selected water-quality constituents 4). Outflow discharge at Beaver Lake dam ranged from 1.76 and reservoir water-surface elevation. m3/s to 2,254 m3/s, with a mean outflow discharge of 35.3 3m /s Another limitation of the Beaver Lake model was that for the period. Four public water-supply withdrawals also are it is a two-dimensional representation of a three-dimensional located on Beaver Lake near the dam. water body. The governing equations are laterally and The water-surface elevation for Beaver Lake varied vertically averaged within layers. Although the model may according to changes in the inflow and outflow for the have accurately represented vertical and longitudinal processes reservoir (fig. 3). Water-surface elevation started off low in within the reservoir, processes that occur laterally, or from January 2006 reaching a minimum elevation March 7, 2006, at shoreline to shoreline perpendicular to the downstream axis, 336.9 m above NGVD of 1929 and remained below the top of may not have been properly represented. conservation pool (341.4 m above NGVD of 1929) for most of 2006. Water-surface elevation reached a maximum elevation of 344.9 m above NGVD of 1929 on April 11, 2008. Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Water-Quality Conditions Beaver Lake Water quality has been monitored in Beaver Lake by the USGS in cooperation with Beaver Water District since This section describes the ambient hydrologic and water- 2001. Water-quality samples are collected from both high- quality conditions for Beaver Lake from January 2006 through flow events and base flow to characterize conditions within December 2010. Streamflow in the three major tributaries, the entire hydrograph. Samples are collected in the reservoir outflow at Beaver Lake dam, and pool elevation for Beaver at sites positioned along the downstream gradient. Vertical Lake are described for the period. In addition, water-quality samples are collected within the water column when the conditions for the three major tributaries and for seven sites lake is thermally stratified in the epilimnion, metalimnion, on Beaver Lake are described for January 2006 through and hypolimnion. When the lake is not thermally stratified, December 2010. These data were retrieved and are still only one sample (epilimnion) is collected. Both inflow and available from the USGS National Water Quality Information reservoir samples are analyzed for a number of constituents,

System Web site: http://waterdata.usgs.gov/ar/nwis/qw/. DS, Cl, and SO4, included. 10 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

10,000 White River near Fayetteville 1,000 100 Mean 10 1 0.1 d n

o 0.01 c e s

r 10,000 e p

s 1,000 Richland Creek at Goshen r e t

e 100 m

c i 10 Mean cu b

n 1 i ,

w 0.1 o l f m

a 0.01 e r t

S 10,000 1,000 War Eagle Creek near Hindsville 100 Mean 10 1 0.1

0.01

10,000 White River at Beaver Dam (outflow) d c n i 1,000 o cu b

se c

n 100 i r Mean

, e p

s o w 10 r tf l e t e O u 1 M

0.1 1/1/2010 7/1/2010 1/1/2011 1/1/2006 7/1/2006 1/1/2007 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009 Date

Figure 4. Mean daily streamflow for White River (site S1), Richland Creek (site S2), and War Eagle Creek (site S3), and hourly outflow at Beaver Lake dam. Ambient Conditions of Dissolved Solids, Chloride, and Sulfate inBeaver Lake 11

Inflow Water Quality Beaver Lake near Lowell (site L3), Beaver Lake at Highway 12 bridge near Rogers (site L4), Beaver Lake near Eureka Water-quality samples were collected at the three main Springs (site L5), War Eagle Creek above White River inflows to Beaver Lake: the White River near Fayetteville near Lowell (site L9), and Beaver Lake downstream from (site S1), Richland Creek at Goshen (site S2), and War Eagle Hickory Creek landing near Springdale (site L10) (table 1, Creek near Hindsville (site S3) (fig. 1). Measured DS, Cl, fig. 1). Concentrations of DS, Cl, and SO were analyzed and SO concentrations varied among the tributaries because 4 4 from samples collected 1 m below the surface at White of differences in land use and contributions from point sources. DS concentrations were greater at Richland Creek River near Goshen (site L1) and 1 m above the bottom, when and War Eagle Creek than White River (fig. 5). The median the water column was thermally stratified. When the water DS concentrations at White River, Richland Creek, and column was isothermal, one sample was collected 1 m below War Eagle Creek were 72, 96, and 109 mg/L, respectively. the surface. Samples were collected 2 m below the surface Cl concentrations were greater at War Eagle Creek than and 2 m above the reservoir bottom at the other six sampling Richland Creek and White River (fig. 5). The median Cl sites. When the water column was isothermal, one sample concentrations at White River, Richland Creek, and War was collected 2 m below the surface. Eagle Creek were 3.1, 4.1, and 6.9 mg/L, respectively. The Measured DS, Cl, and SO4 concentrations varied median SO4 concentration was greater at White River and among lake sites relative to their downstream distance from Richland Creek than War Eagle Creek (fig. 5). The median the tributary point of entry to Beaver Lake (fig. 6). DS, Cl, SO4 concentrations at White River, Richland Creek, and and SO4 concentrations were most variable at the upper end War Eagle Creek were 10.6, 9.5, and 5.8 mg/L, respectively. of the reservoir, White River near Goshen (site L1). The The inflow of DS, Cl, and SO input from groundwater 4 City of Fayetteville discharges wastewater into the White into Beaver Lake was not considered in this study. River, upstream from site L1 near Goshen and downstream Groundwater inflow through the bottom of the reservoir from White River near Fayetteville (site S1). Although the was not considered a boundary condition in the model and therefore not simulated. Tributary base flow into Beaver variability in DS concentrations was greatest at White River Lake was considered to be dominated by groundwater; near Goshen (site L1), the greatest median value (98 mg/L) therefore, groundwater inflow was indirectly accounted for occurred at War Eagle Creek above White River near Lowell in tributary loading. (site L9), followed by Beaver Lake at Highway 412 bridge near Sonora (site L2, 93 mg/L) and Beaver Lake downstream Reservoir Water Quality from Hickory Creek landing near Springdale (site L10, 91 mg/L). Variability and median concentrations for both Cl

Water-quality samples were collected at the seven (5.4 mg/L) and SO4 (13.0 mg/L) were greatest at White River sites in Beaver Lake: White River near Goshen (site L1), near Goshen (site L1) and generally decreased the farther Beaver Lake at Highway 412 bridge near Sonora (site L2), downstream the site was located. 12 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

300 Dissolved Solids 250 r e , s li t

d 200 r i e o l p

s s d m e

a 150 v l o s llig r s i i m D 100 n i

50

0 S1 S2 S3

70 EXPLANATION 60 Chloride Outlier r 50 e 90th percentile li t

r e , 40 75th percentile p e

d s m or i a 30 Ch l llig r

i 50th percentile

m 20

n i

10 25th percentile

0 10th percentile

S1 S2 S3

50 Sulfate 40 r e li t

, pe r

e 30 s m lfa t a u S llig r i 20 m

n i

10

0 S1 S2 S3 Site Figure 5. Distribution of dissolved solids, chloride, and sulfate concentrations for White River (site S1), Richland Creek (site S2), and War Eagle Creek (site S3), 2006–10. Ambient Conditions of Dissolved Solids, Chloride, and Sulfate inBeaver Lake 13

Upstream Downstream 250 Dissolved Solids

r 200 e , s li t

d r i e o l p 150

s s d m e a v l

o 100 s llig r s i i m D

n i 50

0 1 2 9 3 4 5 0 L L L L L L 1 L

50 EXPLANATION Chloride r Outlier

e 40

li t 90th percentile

r e , p e 30 75th percentile d s m or i a 20 Ch l llig r i 50th percentile m

n 10 i

0 25th percentile

10th percentile 1 2 9 3 4 5 0 L L L L L L 1 L

50 Sulfate

r 40 e li t

, pe r

30 e s m lfa t a u

S 20 llig r i m

n i 10

0 1 2 9 3 4 5 0 L L L L L L 1 L

Lake site

Figure 6. Distribution of dissolved solids, chloride, and sulfate concentrations 2 meters (m) below the surface at lake sites L1–L5, L9, and L10, 2006–10. 14 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

Dissolved Solids, Chloride, conditions. The greatest differences between simulated and measured temperatures at any given site generally and Sulfate Fate and Transport occurred in simulating the location of the thermocline. Higher wind speeds result in more mixing, resulting in a Simulations deeper thermocline and lower surface temperatures, whereas lower wind speeds result in a shallower thermocline and Inflow Loads and Concentrations higher surface temperatures. Differences in the thermocline depth between the simulated and measured vertical profiles resulted in high temperature errors because of the rapid Estimated daily DS, Cl, and SO4 concentrations in the Beaver Lake model were determined by dividing daily change and differences in water temperature with depth. S-LOADEST loads by daily discharge and converting to milligrams per liter. S-LOADEST daily concentrations were Dissolved Solids, Chloride, and similar to measured instantaneous concentrations at all three inflow tributaries (figs. 7–9, table 3). In general, estimated Sulfate Concentrations mean daily concentrations followed the seasonal (high-flow/ Simulated DS, Cl, and SO concentrations in model low-flow) cycles of instantaneous measured concentrations. 4 segments 2, 5, 48, 14, 16, 23, and 35 matched well with measured concentrations at lake sites L1, L2, L9, L10, Reservoir Hydrodynamics L3, L4, and L5, respectively (figs. 11–16). The greatest

differences between measured and simulated DS, Cl, and SO4 Simulated water temperatures in Beaver Lake were concentrations occurred at the upstream sites on the White compared to 197 depth profiles of temperature measured River main stem in Beaver Lake: White River near Goshen at seven sites on Beaver Lake (fig. 1). Temperatures were (site L1, model segment 2) and Beaver Lake at Highway adjusted to the measured values for the model period, 412 (site L2, model segment 5). The higher measured January 2006 through December 2010. concentrations likely resulted from wastewater discharges Simulated temperatures compared reasonably well upstream from station L1 that were not included in the model with measured temperatures (fig. 10), and differences varied input, based on the measured and simulated increases in spatially in Beaver Lake for January 2006 through December DS, Cl, and SO4 concentrations between White River near 2010. Differences in temperature between simulated and Fayetteville (site S1) and White River near Goshen (site L1) measured values decreased from site L2 (segment 5) to (figs. 7–8). Not including sites L1 and L2, the AME for DS site L5 (segment 35). The AME ranged from 1.75 °C at site for sites L3, L4, L5, L9, and L10 ranged from 7.64 mg/L at L5 to 2.68 °C at L2, and the RMSE ranged from 2.22 °C site L10 to 11.5 mg/L at L9, and the RMSE ranged from 10.4 at site L5 to 3.35 °C at site L2 from January 2006 through mg/L at site L5 to 15.2 mg/L at site L9 from January 2006 December 2010 (table 4). Among all the sites, the greatest through December 2010 (figs. 11–12, table 4). The AME for differences between measured and simulated data occurred Cl ranged from 0.224 mg/L at site L5 to 1.20 mg/L at site in the upstream part of the reservoir, which is the most L9, and the RMSE ranged from 0.286 mg/L at site L5 to 1.37 dynamic part of the reservoir. The upstream part of the mg/L at site L9 from January 2006 through December 2010 reservoir is the shallowest section of Beaver Lake and has (figs. 13–14, table 4). The AME for SO4 ranged from 1.27 more riverine characteristics than the deep downstream mg/L at site L4 to 1.60 mg/L at site L3, and the RMSE ranged part of the reservoir. The upstream part also receives most from 1.51 mg/L at site L4 to 1.95 mg/L at site L9 from January of the inflow to the reservoir, which creates more dynamic 2006 through December 2010 (figs. 15–16, table 4). Dissolved Solids, Chloride, and Sulfate Fate and Transport Simulations 15

180 160 r

e 140 , s li t

d r i

e 120 o l p

s s d

m 100 e a v l o

s 80 llig r s i i m D

n 60 i 40 20 7/1/2010 1/1/2011 1/1/2010 1/1/2006 7/1/2006 1/1/2007 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009

7

6 r e li t

5 r e , p e

d s 4 m or i a 3 Ch l llig r i m 2 n i

1

0 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009 1/1/2010 7/1/2010 1/1/2011 1/1/2006 7/1/2006 1/1/2007

50

r 40 e li t

, pe r

30 e s m lfa t a u

S 20 llig r i m

n i 10

0 1/1/2006 7/1/2006 1/1/2007 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009 1/1/2010 7/1/2010 1/1/2011

Date

EXPLANATION

Measured concentration Estimated concentration time series

Figure 7. Time-series distributions of measured and S-LOADEST estimated dissolved solids, chloride, and sulfate concentrations at White River (site S1). 16 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

250 r e , 200 s li t

d r i e o l p

s s

d 150 m e a v l o s llig r s i

i 100 m D

n i 50

0 7/1/2010 1/1/2011 1/1/2010 1/1/2006 7/1/2006 1/1/2007 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009

12

r 10 e li t

r e

, 8 p e

d s m or i

a 6 Ch l llig r i

m 4

n i

2

0 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009 1/1/2010 7/1/2010 1/1/2011 1/1/2006 7/1/2006 1/1/2007

35

30

r 25 e li t

20 , pe r

e s m

lfa t 15 a u S llig r i 10 m

n i 5

0 1/1/2006 7/1/2006 1/1/2007 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009 1/1/2010 7/1/2010 1/1/2011

Date

EXPLANATION

Measured concentration Estimated concentration time series

Figure 8. Time-series distributions of measured and S-LOADEST estimated dissolved solids, chloride, and sulfate concentrations at Richland Creek (site S2). Dissolved Solids, Chloride, and Sulfate Fate and Transport Simulations 17

300

250 r e , s li t

d r

i 200 e o l p

s s d m

e 150 a v l o s llig r s i

i 100 m D

n i 50

0 1/1/2010 7/1/2010 1/1/2011 1/1/2006 7/1/2006 1/1/2007 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009

70

60 r e li t

50 r e , p e

d 40 s m or i a 30 Ch l llig r i 20 m

n i 10

0 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009 1/1/2010 7/1/2010 1/1/2011 1/1/2006 7/1/2006 1/1/2007

10 r

e 8 li t

, pe r

e 6 s m lfa t a u S

llig r 4 i m

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0 1/1/2006 7/1/2006 1/1/2007 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009 1/1/2010 7/1/2010 1/1/2011

Date

EXPLANATION

Measured concentration Estimated concentration time series

Figure 9. Time-series distributions of measured and S-LOADEST estimated dissolved solids, chloride, and sulfate concentrations at War Eagle Creek (site S3). 18 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

Table 3. Statistics measuring error between measured and S-LOADEST estimated dissolved solids, chloride, and sulfate concentrations at White River (S1), Richland Creek (S2), and War Eagle Creek (S3).

[AME, absolute mean error; RMSE, root mean square error; DS, dissolved solid; Cl, chloride; SO4 , sulfate] White River (S1) Richland Creek (S2) War Eagle Creek (S3) Constituent AME RMSE AME RMSE AME RMSE DS 12.8 18.2 19.2 22.9 17.9 26.1 Cl 0.672 0.919 0.913 1.150 3.994 8.586

SO4 3.271 5.701 3.123 4.566 2.242 6.912

Dissolved Solids, Chloride, and Sulfate the baseline condition, at model segments 2, 5, 48, 14, 16, 23, Fate and Transport and 35 at 2 m below the surface, occurred when loads were increased by a factor of 5.0 and 10.0 times baseline loads. Average daily DS, Cl, and SO concentrations, from Fifteen DS, Cl, and SO4 fate and transport scenarios were 4 compared to the baseline (calibrated) simulation. Daily DS, January 2006 through December 2010, for each constituent

Cl, and SO4 concentrations in the baseline simulation from the for the baseline and each loading scenario at each of the White River near Fayetteville (site S1) and War Eagle Creek seven model segments both 2 m below the surface and 2 near Hindsville (site S3) (fig. 1), individually and the two m above the bottom are presented in tables 5–7 and figures tributaries together, were increased by factors of 1.2, 1.5, 2.0, 18–26. Concentrations were greater in the reservoir at model 5.0, and 10.0 times; flow (discharge) remained unchanged. segments closer to where the tributaries entered the reservoir:

These scenarios resulted in increased inflow DS, Cl, and SO4 sites L1 and L2 (segments 2 and 5) for increased loads from loading in each tributary by a factor of 1.2, 1.5, 2.0, 5.0, and White River near Fayetteville (site S1) and sites L9 and L10 10.0 times baseline. It should be noted again that contributions (segments 48 and 14) for increased loads from War Eagle from the City of Fayetteville’s WWTP were not included in Creek near Hindsville. Concentrations resulting from the either the baseline model or any of the loading scenarios. increase in loading became more diluted farther downstream Daily DS, Cl, and SO concentrations in the 15 scenarios were 4 from the source. Differences in concentrations between the compared to daily baseline concentrations at the seven model baseline condition and the 1.2, 1.5, and 2.0 times baseline segments (2, 5, 48, 14, 16, 23, and 35) corresponding to lake concentration scenarios were smaller than the differences in sites L1, L2, L9, L10, L3, L4, and L5, respectively. Daily the 5.0 and 10.0 times baseline concentration scenarios. The baseline and scenario concentrations were reported at the results for both the 2 m below the surface and 2 m above the seven model segments 2 m below the surface and 2 m above bottom were similar, with the exception of concentrations the bottom, corresponding to the depths where water samples resulting from the increased loading factors (5.0 and 10.0 were collected. A time-series plot of baseline and scenario results from increasing loading scenarios from White River times), where concentrations 2 m above the bottom were near Fayetteville (site S1) and War Eagle Creek near Hindsville consistently greater than those 2 m below the surface at (site S3), individually and the two tributaries together, for each most segments. During thermal stratification, inflow water of the seven model segments at 2 m below the surface was temperature often is lower (more dense) than the surface of prepared to visualize differences for the period January 2006 the reservoir, which causes the inflow to dip below the warmer through December 2010 (fig. 17A–C). For all three constituents surface layer into a layer of equal density, carrying DS, CL, and SO with it. During these times, concentrations will be (DS, Cl, and SO4), the loads that were increased by factors of 4 1.2, 1.5, and 2.0 times baseline produced only slightly higher higher in the deeper water than the surface, as shown in the concentrations in the model segments than those in the baseline average concentrations at the increased loading rates in tables condition. Much greater separation in concentrations from 5–7 and figures 18–26. Dissolved Solids, Chloride, and Sulfate Fate and Transport Simulations 19 5 5 5 3 3 3 0 e 8 8 8 1 r 2 2 2 0 ur e u 2 t 1 1 1 2 2 2 a r 4 4 4 era t 22 / e 1 1 1 / p p 9/5/2007 1 5/6/2009 7 m 7 7 ON 1 m e e t t

0 0 0 d AT I 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 e 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 t N ure d a A l 5 5 5 L u 3 3 3 P ea s m 8 8 8 i 2 2 2 X M S 01 0 E 1 1 1 2 2 2 2 / 6 4 4 4 1 1 1 1 / 7/10/2007 9 7 7 7 3/10/2009 0 0 0 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 5 5 5 3 3 3 8 8 8 2 2 2 01 0 1 1 1 2 2 2 2 / 5 4 4 4 1 1 1 1 / 5/30/2007 7 7 7 7 12/17/2008 0 0 0 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 5 5 5 3 3 3 8 8 8 2 2 2 01 0 1 1 1 2 2 2 2 / 8 4 4 4 1 1 1 1 / 2/22/2007 5 7 7 7 10/22/2008 0 0 0 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 s u i 5 5 5 s 3 3 3 l 0 8 8 e 8 2 2 2 c

1 1 1 2 2 s 2 / 20 1 e 4 4 4 1 1 2 4 1 3 / 7 7 12/12/2006 7 8/27/2008 gr e e 0 0 0 d

0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 n i

, 5 5 5 3 3 3 0 8 8 8 ur e 2 2 2 0 1 t 1 1 1 a / 2 2 2 2 r 4 4 e 4 2 5 1 1 1 p 1 / 7 10/30/2006 7 7 6/10/2008 m e 0 t 0 0

0 5 0 5 0 5 r 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 e t 5 5 5 a 3 3 3 9 8 8 8 0 W 2 2 2 0 2 1 1 1 / 2 2 2 1 4 4 4 1 1 1 1 8/22/2006 5/5/2008 7 7 7 11 / 0 0 0 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 5 5 5 3 3 3 9 8 8 8 2 2 2 0 1 1 1 2 2 2 / 2 4 4 4 1 1 1 8 1 7/17/2006 8 / 7 7 7 2/19/2008 0 0 0 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 5 5 5 3 3 3 8 8 8 2 2 2 00 9 1 1 1 2 2 2 2 / 4 4 4 7 1 1 1 / 7 5/22/2006 7 7 1/15/2008 7 0 0 0 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 5 5 5 3 3 3 8 8 8 9 2 2 2 1 1 1 2 2 2 20 0 / 4 4 4 9 1 1 1 / Selected simulated and measured water-temperature profiles for Beaver Lake at Highway 412 bridge near Eureka Springs, Arkansas (site L5, segment 35). Selected simulated and measured water-temperature 6 2/24/2006 7 7 7 10/24/2007

0 0 0

0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5

0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6 1 1 2 2 3 3 4 4 5 5 6 6

e c a f ur s w o l e b s r e t e m n i , h t p e D Figure 10. 20 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

Table 4. CE-QUAL-W2 model calibration evaluation statistics for water temperature, dissolved solids, chloride, and sulfate for Beaver Lake sites, January 2006 through December 2010.

[Difference is simulated minus measured]

Minimum Maximum Mean Absolute Root mean Station Year difference difference difference mean error square error Temperature, in degrees Celsius L1, White River near Goshen 2006–2010 -4.35 8.95 1.44 2.55 3.04 (segment 2)1 L2, Beaver Lake at Highway 412 2006–2010 -3.66 9.77 2.15 2.68 3.35 bridge near Sonora (segment 5)1 L9, War Eagle Creek above White 2007–2010 -2.74 7.78 2.28 2.62 3.19 River near Lowell (segment 48) L10, Beaver Lake downstream from 2008–2010 -4.47 7.32 1.24 2.04 2.61 Hickory Creek Landing near Springdale (segment 14) L3, Beaver Lake near Lowell 2006–2010 -5.31 6.84 1.35 2.30 2.77 (segment 16) L4, Beaver Lake at Highway 12 2006–2010 -3.06 6.97 1.05 1.92 2.40 bridge near Rogers (segment 23) L5, Beaver Lake near Eureka 2006–2010 -6.13 7.39 0.76 1.75 2.22 Springs (segment 35) Dissolved solids, in milligrams per liter L1, White River near Goshen 2006–2010 -153 19.8 -24.1 29.2 45.1 (segment 2)1 L2, Beaver Lake at Highway 412 2006–2010 -74.7 18.3 -17.7 19.3 24.7 bridge near Sonora (segment 5)1 L9, War Eagle Creek above White 2007–2010 -50.8 14.8 -5.96 11.5 15.2 River near Lowell (segment 48) L10, Beaver Lake downstream 2008–2010 -27.4 5.97 -5.20 7.64 10.8 from Hickory Creek landing near Springdale (segment 14) L3, Beaver Lake near Lowell 2006–2010 -36.9 18.2 -6.23 10.3 13.3 (segment 16) L4, Beaver Lake at Highway 12 2006–2010 -38.0 12.1 -7.71 9.55 12.5 bridge near Rogers (segment 23) L5, Beaver Lake near Eureka 2006–2010 -29.1 14.8 -6.11 7.94 10.4 Springs (segment 35) Chloride, in milligrams per liter L1, White River near Goshen 2006–2010 -39.1 0.725 -3.92 4.17 8.13 (segment 2)1 L2, Beaver Lake at Highway 412 2006–2010 -7.60 1.04 -1.68 1.83 2.60 bridge near Sonora (segment 5)1 L9, War Eagle Creek above White 2007–2010 -2.10 2.41 0.80 1.20 1.37 River near Lowell (segment 48) L10, Beaver Lake downstream 2008–2010 -2.35 1.01 0.04 0.65 0.81 from Hickory Creek landing near Springdale (segment 14) L3, Beaver Lake near Lowell 2006–2010 -2.84 1.33 -0.29 0.69 0.93 (segment 16) L4, Beaver Lake at Highway 12 2006–2010 -2.50 0.92 -0.33 0.56 0.74 bridge near Rogers (segment 23) L5, Beaver Lake near Eureka 2006–2010 -0.82 0.58 -0.01 0.22 0.29 Springs (segment 35) Dissolved Solids, Chloride, and Sulfate Fate and Transport Simulations 21

Table 4. CE-QUAL-W2 model calibration evaluation statistics for water temperature, dissolved solids, chloride, and sulfate for Beaver Lake sites, January 2006 through December 2010.—Continued

[Difference is simulated minus measured]

Minimum Maximum Mean Absolute Root mean Station Year difference difference difference mean error square error Sulfate, in milligrams per liter L1, White River near Goshen 2006–2010 -32.6 5.01 -3.36 5.32 8.73 (segment 2)1 L2, Beaver Lake at Highway 412 2006–2010 -7.24 8.89 0.10 2.49 3.12 bridge near Sonora (segment 5)1 L9, War Eagle Creek above White 2007–2010 -1.00 5.26 1.44 1.58 1.95 River near Lowell (segment 48) L10, Beaver Lake downstream 2008–2010 -2.03 2.33 0.916 1.40 1.55 from Hickory Creek landing near Springdale (segment 14) L3, Beaver Lake near Lowell 2006–2010 -3.47 5.87 1.31 1.60 1.93 (segment 16) L4, Beaver Lake at Highway 12 2006–2010 -2.19 4.55 1.10 1.27 1.51 bridge near Rogers (segment 23) L5, Beaver Lake near Eureka 2006–2010 0.47 2.41 1.54 1.54 1.59 Springs (segment 35) 1Model simulation does not include dissolved solids, chloride, and sulfate constituents from the Fayetteville, Arkansas, wastewater-treatment plant, which influence measured concentrations. 22 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

250 L1, White River at Goshen, segment 2 200

150

100

50

0 250

200 L2, Beaver Lake at Hwy. 412 bridge near Sonora, segment 5 r e

t 150 i l

r e p

100 s m a 50 g r i l l i m

0 n i

,

s 250 d i o l

s L9, War Eagle Creek above White River near Lowell, segment 48 200 d e

ol v 150 is s D 100

50

0 250 L10, Beaver Lake downstream from Hickory Creek landing near Springdale, segment 14 200

150

100

50

0 1/1/2010 7/1/2010 1/1/2011 1/1/2006 7/1/2006 1/1/2007 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009 Date

EXPLANATION

Measured concentration Simulated concentration

Figure 11. Simulated and measured dissolved solids concentrations 2 meters (m) below the surface in Beaver Lake, Arkansas. Dissolved Solids, Chloride, and Sulfate Fate and Transport Simulations 23

250

200 L3, Beaver Lake near Lowell, segment 16

150

100

50 r e t

i 0 l

r 250 e p

s L4, Beaver Lake at Hwy. 12 bridge near Rogers, segment 23 200 m a g r i l

l 150 i m

n i

100 , s d i

o l 50 s

d e 0 ol v

is s 250 D L5, Beaver Lake near Eureka Springs, segment 35 200

150

100

50

0 1/1/2010 7/1/2010 1/1/2011 1/1/2007 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009 7/1/2006 1/1/2006 Date

EXPLANATION

Measured concentration Simulated concentration

Figure 11. Simulated and measured dissolved solids concentrations 2 meters (m) below the surface in Beaver Lake, Arkansas.—Continued 24 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

250 L1, White River at Goshen, segment 2 200

150

100

50

0

250 L2, Beaver Lake at Hwy. 412 bridge near Sonora, segment 5 200

150

100

50

0 250 L9, War Eagle Creek above White River near Lowell, segment 48 200

150 ol ved solids, in milligrams per liter is s

D 100

50

0

250 L10, Beaver Lake downstream from Hickory Creek landing near Springdale, segment 14 200

150 No measured hypolimnetic dissolved solids samples 100

50

0 1/1/2010 7/1/2010 1/1/2011 1/1/2006 7/1/2006 1/1/2007 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009 Date

EXPLANATION

Measured concentration Simulated concentration

Figure 12. Simulated and measured dissolved solids concentrations 2 meters (m) above the bottom in Beaver Lake, Arkansas. Dissolved Solids, Chloride, and Sulfate Fate and Transport Simulations 25

250

200 L3, Beaver Lake near Lowell, segment 16

150

100

50

0

250

200 L4, Beaver Lake at Hwy. 12 bridge near Rogers, segment 23

150

100

50 ol ved solids, in milligrams per liter 0 is s D 250

200 L5, Beaver Lake near Eureka Springs, segment 35

150

100

50

0 1/1/2010 7/1/2010 1/1/2011 7/1/2006 1/1/2007 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009 1/1/2006 Date

EXPLANATION

Measured concentration Simulated concentration

Figure 12. Simulated and measured dissolved solids concentrations 2 meters (m) above the bottom in Beaver Lake, Arkansas.—Continued 26 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

50

40 L1, White River at Goshen, segment 2 30

20

10

0 50

40 L2, Beaver Lake at Hwy. 412 bridge near Sonora, segment 5

30

20

r pe r liter 10

0 50

n , i n milligrams 40 L9, War Eagle Creek above White River near Lowell, segment 48

30 Ch loride 20

10

0 50

40 L10, Beaver Lake downstream from Hickory Creek landing near Springdale, segment 14 30

20

10

0 1/1/2010 7/1/2010 1/1/2011 1/1/2006 7/1/2006 1/1/2007 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009 Date

EXPLANATION

Measured concentration Simulated concentration

Figure 13. Simulated and measured chloride concentrations 2 meters (m) below the surface in Beaver Lake, Arkansas. Dissolved Solids, Chloride, and Sulfate Fate and Transport Simulations 27

50

40 L3, Beaver Lake near Lowell, segment 16

30

20

10

0

50

40 L4, Beaver Lake at Hwy. 12 bridge near Rogers, segment 23

30

20

e, in milligrams per liter 10

0 Chl orid

50

40 L5, Beaver Lake near Eureka Springs, segment 35

30

20

10

0 7/1/2010 1/1/2011 1/1/2010 7/1/2007 7/1/2008 7/1/2009 7/1/2006 1/1/2007 1/1/2008 1/1/2009 1/1/2006 Date

EXPLANATION

Measured concentration Simulated concentration

Figure 13. Simulated and measured chloride concentrations 2 meters (m) below the surface in Beaver Lake, Arkansas.—Continued 28 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

50

40 L1, White River at Goshen, segment 2

30

20

10

0 50

40 L2, Beaver Lake at Hwy. 412 bridge near Sonora, segment 5

30

20

10

0

50

e, in milligrams per liter 40 L9, War Eagle Creek above White River near Lowell, segment 48

Chl orid 30

20

10

0 50

40 L10, Beaver Lake downstream from Hickory Creek landing near Springdale, segment 14 30

20

10 No measured hypolimnetic TDS samples

0 1/1/2010 7/1/2010 1/1/2011 1/1/2006 7/1/2006 1/1/2007 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009 Date

EXPLANATION

Measured concentration Simulated concentration

Figure 14. Simulated and measured chloride concentrations 2 meters (m) above the bottom in Beaver Lake, Arkansas. Dissolved Solids, Chloride, and Sulfate Fate and Transport Simulations 29

50

40 L3, Beaver Lake near Lowell, segment 16

30

20

10

0

50 L4, Beaver Lake at Hwy. 12 bridge near Rogers, segment 23 40

30

20

e, in milligrams per liter 10

Chl orid 0

50

40 L5, Beaver Lake near Eureka Springs, segment 35

30

20

10

0 7/1/2010 1/1/2011 1/1/2010 7/1/2007 7/1/2008 7/1/2009 7/1/2006 1/1/2007 1/1/2008 1/1/2009 1/1/2006 Date

EXPLANATION

Measured concentration Simulated concentration

Figure 14. Simulated and measured chloride concentrations 2 meters (m) above the bottom in Beaver Lake, Arkansas.—Continued 30 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

50 L1, White River at Goshen, segment 2 40

30

20

10

0

50

40 L2, Beaver Lake at Hwy. 412 bridge near Sonora, segment 5

30

20

10

0 ll ig rams per liter 50 n mi , i n 40 L9, War Eagle Creek above White River near Lowell, segment 48

Sulfate 30

20

10

0

50

40 L10, Beaver Lake downstream from Hickory Creek landing near Springdale, segment 14

30

20

10

0 1/1/2010 7/1/2010 1/1/2011 1/1/2006 7/1/2006 1/1/2007 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009 Date

EXPLANATION

Measured concentration Simulated concentration

Figure 15. Simulated and measured sulfate concentrations 2 meters (m) below the surface in Beaver Lake, Arkansas. Dissolved Solids, Chloride, and Sulfate Fate and Transport Simulations 31

50 L3, Beaver Lake near Lowell, segment 16 40

30

20

10

0 50

40 L4, Beaver Lake at Hwy. 12 bridge near Rogers, segment 23

30 ll ig rams per liter 20

n mi , i n 10

Sulfate 0 50 L5, Beaver Lake near Eureka Springs, segment 35 40

30

20

10

0 1/1/2010 7/1/2010 1/1/2011 1/1/2007 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009 7/1/2006 1/1/2006 Date

EXPLANATION

Measured concentration Simulated concentration

Figure 15. Simulated and measured sulfate concentrations 2 meters (m) below the surface in Beaver Lake, Arkansas.—Continued 32 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

50 L1, White River at Goshen, segment 2 40

30

20

10

0

50

40 L2, Beaver Lake at Hwy. 412 bridge near Sonora, segment 5

30

20 li ter

r pe r 10

0 rams llig rams 50

40 L9, War Eagle Creek above White River near Lowell, segment 48 lfate, in mi

Su 30

20

10

0

50 L10, Beaver Lake downstream from Hickory Creek landing near Springdale, segment 14 40

30

20 No measured hypolimnetic TDS samples 10

0 1/1/2010 7/1/2010 1/1/2011 1/1/2006 7/1/2006 1/1/2007 7/1/2007 1/1/2008 7/1/2008 1/1/2009 7/1/2009 Date

EXPLANATION

Measured concentration Simulated concentration

Figure 16. Simulated and measured sulfate concentrations 2 meters (m) above the bottom in Beaver Lake, Arkansas. Dissolved Solids, Chloride, and Sulfate Fate and Transport Simulations 33

50

40 L3, Beaver Lake near Lowell, Segment 16

30

20

10

0 50 lite r 40 L4, Beaver Lake at Hwy. 12 bridge near Rogers, segment 23 pe r s m

a 30 llig r i

m 20

e, i n 10 lfa t u

S 0 50

40 L5, Beaver Lake near Eureka Springs, segment 35

30

20

10

0 7/1/2010 1/1/2011 1/1/2010 7/1/2007 7/1/2008 7/1/2009 7/1/2006 1/1/2007 1/1/2008 1/1/2009 1/1/2006 Date

EXPLANATION

Measured concentration Simulated concentration

Figure 16. Simulated and measured sulfate concentrations 2 meters (m) above the bottom in Beaver Lake, Arkansas.—Continued

34 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10 1/1/2011

s e d 7/1/2010 d i i at e r f

o

so l Su l 1/1/2010 Ch l

ved 7/1/2009

Disso l 1/1/2009 8

4

t 7/1/2008 e n t e a

D 1/1/2008

Seg m

7/1/2007

1/1/2007

7/1/2006 1/1/2006 0 0 0 80 60 40 20 80 60 40 20

800 600 400 200 100 100

1200 1000 1/1/2011

s e d 7/1/2010 i

so l 1/1/2010 oad) Sulfa t

Chloride

ved 7/1/2009 t plant l

Disso l 1/1/2009 5

t

t n 7/1/2008 e ATIO N t e a o u

D

t h 1/1/2008 PLA N Se g m

X

E

7/1/2007 1/1/2007

1.2 times loading 1.5 times loading 2.0 times loading 5.0 times loading 10.0 times loading Baseline (w i wastewater-treatme n

7/1/2006 1/1/2006 0 0 0

40 30 20 10 80 60 40 20

800 700 600 500 400 300 200 100 140 120 100 1/1/2011

s d 7/1/2010 i at e

f

so l 1/1/2010 Su l

Chloride

ved 7/1/2009

Disso l 1/1/2009

2

t n 7/1/2008 e t e a

D 1/1/2008

Seg m

7/1/2007

1/1/2007

7/1/2006 1/1/2006 0 0 0 Dissolved solids, chloride, and sulfate concentrations 2 meters (m) below the surface at model segments 2, 5, 48, 14, 16, 23 35 from baseline increased 50 40 30 20 10 80 60 40 20

800 600 400 200 200 180 160 140 120 100

1200 1000

r r e t i l r e p r lite r e p r e t i l r e p

s m a igr l l i m n i s m a r g i ll i m s m a r g i l l i m

, s d i l o s d e v l o s s Di n i , e id r o l Ch n i , e t fa l u S Figure 17. Eagle Creek near Hindsville, Ark. (site S3). loading scenarios from both White River near Fayetteville, Arkansas, (site S1) and War

Dissolved Solids, Chloride, and Sulfate Fate and Transport Simulations 35

1/1/2011

7/1/2010

1/1/2010

7/1/2009 1/1/2009 6

1 t 7/1/2008 e t n a e

D 1/1/2008 Se g m

s d 7/1/2007 i

oad)

so l 1/1/2007 e

ved

d e i r 7/1/2006 t plant l o

Ch l Disso l Sulfa t 1/1/2006 0 0 0 t ATIO N 50 40 30 20 10 80 60 40 20

800 700 600 500 400 300 200 100 100

o u 1/1/2011 t h PLA N

X

E 7/1/2010 1/1/2010

1.2 times loading 1.5 times loading 2.0 times loading 5.0 times loading 10.0 times loading Baseline (w i wastewater-treatme n

7/1/2009 1/1/2009 4

1

7/1/2008 e t t n a e

D 1/1/2008 Se g m

s d 7/1/2007 i

so l 1/1/2007 e

ved

d e i r 7/1/2006 o

Sulfa t Disso l Ch l 1/1/2006 0 0 0

50 40 30 20 10 80 60 40 20

800 700 600 500 400 300 200 100 100

r r e t i l r e p r lite r e p r e t i l r e p

s m a igr l l i m n i s m a r g i ll i m s m a r g i l l i m

, s d i l o s d e v l o s s Di n i , e id r o l Ch n i , e t fa l u S Dissolved solids, chloride, and sulfate concentrations 2 meters (m) below the surface at model segments 2, 5, 48, 14, 16, 23 35 from baseline increased

Figure 17. Eagle Creek near Hindsville, Ark. (site S3).—Continued loading scenarios from both White River near Fayetteville, Arkansas, (site S1) and War

36 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

1/1/2011

7/1/2010

1/1/2010

7/1/2009 1/1/2009 6

1

t 7/1/2008 e t n a

e

D 1/1/2008 Se g m

s d 7/1/2007 i

oad)

so l 1/1/2007 e

ved

d e i r 7/1/2006 t plant l o

Ch l Disso l Sulfa t 1/1/2006 0 0 0 t ATIO N 50 40 30 20 10 80 60 40 20

800 700 600 500 400 300 200 100 100

o u 1/1/2011 t h PLA N

X

E 7/1/2010 1/1/2010

1.2 times loading 1.5 times loading 2.0 times loading 5.0 times loading 10.0 times loading Baseline (w i wastewater-treatme n

7/1/2009 1/1/2009 4

1

7/1/2008 e t t n a

e

D 1/1/2008 Se g m

s d 7/1/2007 i

so l 1/1/2007 e

ved

d e i r 7/1/2006 o

Sulfa t Disso l Ch l 1/1/2006 0 0 0

50 40 30 20 10 80 60 40 20

800 700 600 500 400 300 200 100 100

r r e t i l r e p r lite r e p r e t i l r e p

s m a igr l l i m n i s m a r g i ll i m s m a r g i l l i m

, s d i l o s d e v l o s s Di n i , e id r o l Ch n i , e t fa l u S Dissolved solids, chloride, and sulfate concentrations 2 meters (m) below the surface at model segments 2, 5, 48, 14, 16, 23 35 from baseline increased

Figure 17. Eagle Creek near Hindsville, Ark. (site S3).—Continued loading scenarios from both White River near Fayetteville, Arkansas, (site S1) and War Dissolved Solids, Chloride, and Sulfate Fate and Transport Simulations 37 4.09 4.22 4.43 4.76 7.34 8.93 9.39 11.4 84.2 87.4 92.6 12.6 10.1 21.0 40.3 101 169 307 bottom 2 m above (site L5) Segment 35 4.00 4.12 4.30 4.58 6.26 8.77 8.90 9.29 9.92 84.2 87.1 91.6 99.0 10.9 16.8 25.7 142 206 surface 2 m below 4.14 4.28 4.51 4.89 7.80 8.88 9.42 11.9 84.3 88.1 94.4 13.4 10.3 22.9 43.6 105 182 327 bottom 2 m above (site L4) Segment 23 4.00 4.28 4.47 4.91 7.37 8.75 9.42 83.9 88.1 96 10.80 10.4 12.0 20.5 32.6 107 170 258 surface 2 m below 4.11 4.27 4.54 4.98 8.19 8.76 9.41 83.5 88.2 95.4 14.0 10.5 12.3 24.5 46.1 108 193 344 bottom 2 m above (site L3) Segment 16 4.22 4.39 4.75 6.80 8.37 8.79 9.61 85.5 90.9 12.8 10.8 14.1 23.7 39.2 100 137 192 304 surface 2 m below 4.07 4.27 4.57 5.06 8.55 8.69 9.46 83.1 88.5 96.5 14.9 10.6 12.7 25.9 49.4 110 202 367 bottom 2 m above (site L10) Segment 14 4.30 4.46 4.83 5.40 8.63 8.80 9.63 86.1 91.5 13.2 10.9 12.9 24.3 40.3 Sulfate, in milligrams per liter Chloride, in milligrams per liter 115 100 197 313 surface 2 m below Dissolved solids, in milligrams per liter 3.48 3.92 4.43 5.28 9.87 11.0 80.8 90.0 10.8 20.8 13.0 16.2 37.3 74.5 103 126 269 524 bottom 2 m above (site L2) Segment 5 3.38 3.85 4.43 5.35 11.5 81.0 90.9 10.8 19.0 10.5 13.6 17.0 37.2 66.8 105 129 269 477 surface 2 m below 3.50 3.86 4.48 5.67 11.4 85.8 94.2 13.3 26.3 12.6 15.6 20.5 50.2 111 142 337 671 101 bottom 2 m above (site L1) Segment 2 3.22 3.70 4.38 5.36 11.3 80.4 91.7 10.8 19.1 12.7 15.0 18.7 39.4 71.3 108 134 273 485 surface 2 m below Average daily dissolved solids, chloride, and sulfate concentrations for baseline condition increasing loading factor scenarios from White River near Fayetteville Average

Loading factor 1.0x (baseline) 1.2x 1.5x 2.0x 5.0x 10.0x 1.0x (baseline) 1.2x 1.5x 2.0x 5.0x 10.0x 1.0x (baseline) 1.2x 1.5x 2.0x 5.0x 10.0x Table 5. Table for the period January 2006 through December 2010, 2 meters (m) below surface and m above bottom at model segments 2, 5, 14, 16, 23, 35 (fig. 2). (site S1) only, [m, meter; x, times] 38 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10 4.09 4.28 4.61 5.21 9.50 8.93 9.07 9.32 9.74 84.2 87.0 91.8 17.2 13.2 20.0 101 168 293 bottom 2 m above (site L5) Segment 35 4.00 4.17 4.42 4.82 7.12 8.90 9.03 9.26 9.63 11.7 84.2 86.7 90.7 97.3 10.6 14.8 134 190 surface 2 m below 4.14 4.38 4.80 5.53 8.88 9.01 9.29 9.81 84.3 87.8 93.8 10.28 17.9 13.7 20.0 105 178 296 bottom 2 m above (site L4) Segment 23 4.00 4.25 4.61 5.17 8.22 8.75 8.98 9.31 9.83 83.9 87.8 93.4 12.7 12.6 16.6 102 151 222 surface 2 m below 4.11 4.40 4.87 5.68 8.76 8.93 9.25 9.84 83.5 87.8 94.6 10.8 19.8 14.0 21.6 107 186 325 bottom 2 m above (site L3) Segment 16 4.22 4.48 4.95 5.69 9.82 8.79 9.06 9.46 85.5 89.8 96.9 15.8 10.1 13.6 18.4 108 170 259 surface 2 m below 4.07 4.40 4.90 5.78 8.69 8.90 9.26 9.90 11.3 83.1 88.0 95.3 21.3 14.4 22.8 109 194 348 bottom 2 m above (Site L10) Segment 14 4.30 4.56 5.05 5.82 8.80 9.08 9.50 86.1 90.4 97.8 10.1 16.4 10.2 13.7 18.7 Sulfate, in milligrams per liter Chloride, in milligrams per liter 110 173 264 surface 2 m below Dissolved solids, in milligrams per liter 3.48 3.76 4.01 4.48 7.8 9.87 9.81 9.99 80.8 83.9 87.7 94.8 15.4 10.3 12.9 19.1 145 262 bottom 2 m above (site L2) Segment 5 3.38 3.57 3.72 3.98 5.74 9.12 11.9 81.0 82.6 84.8 88.7 10.5 10.2 10.3 10.5 14.6 115 166 surface 2 m below 5.15 5.49 6.39 7.91 7.94 8.51 9.17 90.4 97.3 16.5 31.0 10.3 16.9 28.0 110 132 255 463 bottom 2 m above (site L1) Segment 2 5.64 5.88 6.71 7.96 7.79 8.53 9.34 95.1 13.6 20.2 10.5 15.5 20.8 114 102 133 216 309 surface 2 m below Average daily dissolved solids, chloride, and sulfate concentrations for baseline condition and increasing loading scenarios from War Eagle Creek (site S3) only, for the Eagle Creek (site S3) only, daily dissolved solids, chloride, and sulfate concentrations for baseline condition increasing loading scenarios from War Average

Loading factor 1.0x (baseline) 1.2x 1.5x 2.0x 5.0x 10.0x 1.0x (baseline) 1.2x 1.5x 2.0x 5.0x 10.0x 1.0x (baseline) 1.2x 1.5x 2.0x 5.0x 10.0x Table 6. Table period January 2006 through December 2010, 2 meters (m) below the surface and m above bottom at model segments 48, 5, 14 , 16, 23, 35 (fig. 2). [m, meter; x, times] Dissolved Solids, Chloride, and Sulfate Fate and Transport Simulations 39 4.09 3.74 4.95 5.86 8.93 84.2 92.2 12.7 23.4 12.7 10.5 12.2 24.0 43.7 118 100 247 455 bottom 2 m above (site L5) Segment 35 4.00 4.28 4.71 5.40 9.33 8.90 9.45 11.7 84.2 89.8 98.2 15.5 10.3 19.6 32.2 112 191 315 surface 2 m below 4.14 4.52 5.18 6.20 8.88 9.58 84.3 91.7 13.1 23.9 10.7 12.6 25.0 46.6 104 124 255 465 bottom 2 m above (site L4) Segment 23 4.00 4.43 5.07 6.07 8.75 9.63 11.5 83.9 92.5 19.8 10.9 13.0 24.5 41.6 105 125 236 403 surface 2 m below 4.11 4.56 5.28 6.46 8.76 9.59 83.5 92.3 13.6 25.2 10.9 13.1 26.3 50.2 106 128 266 498 bottom 2 m above (site L3) Segment 16 4.22 4.71 5.53 6.80 8.79 9.88 11.5 85.5 95.7 13.9 24.5 14.1 28.6 50.3 111 137 277 489 surface 2 m below 4.07 4.58 5.36 6.63 8.69 9.65 11.1 83.1 93.0 14.1 26.5 13.5 27.8 53.3 108 132 276 524 bottom 2 m above (site L10) Segment 14 4.30 4.80 5.66 7.01 8.80 9.92 11.6 86.1 96.5 14.6 25.9 14.3 29.8 52.9 Sulfate, in milligrams per liter Chloride, in milligrams per liter 113 140 289 513 surface 2 m below Dissolved solids, in milligrams per liter 3.48 4.07 4.82 6.04 9.87 11.1 80.8 92.3 13.4 26.7 13.2 16.6 38.4 77.2 109 136 305 607 bottom 2 m above (site L2) Segment 5 3.38 3.95 4.67 5.84 11.6 81.0 92.3 12.9 24.6 10.5 13.8 17.4 39.2 73.8 109 136 301 570 surface 2 m below 3.50 3.91 4.58 5.87 11.4 85.8 94.9 14.0 28.0 12.6 15.7 20.6 50.5 112 145 347 697 102 bottom 2 m above (site L1) Segment 2 3.22 3.74 4.45 5.51 11.5 11.3 80.4 92.2 20.7 12.7 15.0 18.8 40.2 73.2 109 136 283 512 surface 2 m below Average daily dissolved solids, chloride, and sulfate concentrations for baseline condition increasing loading factor scenarios from White River near Fayetteville Average

Loading factor 1.0x (baseline) 1.2x 1.5x 2.0x 5.0x 10.0x 1.0x (baseline) 1.2x 1.5x 2.0x 5.0x 10.0x 1.0x (baseline) 1.2x 1.5x 2.0x 5.0x 10.0x Table 7. Table Eagle Creek near Hindsville (site S3), for the period January 2006 through December 2010, 2 meters (m) below surface and m above bottom at model (site S1) and War segments 2, 5, 14, 16, 23, and 35 (fig. 2). [m, meter; x, times] 40 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10 X X

10.0 10.0 X X

5.0 5.0 X X

2.0 2.0 X X

1.5 1.5 X X

1.2 1.2 5 4 3

1 t t n n X X e e

* * 1.0 1.0 Seg m Se g m 0 0 0 0 0 0 0 0 0 0 80 0 60 0 40 0 20 0 8 6 4 2 to r X X fa c

g n 10.0 10.0 i m X X loa d

o t t 5.0 5.0 o S1 )

surfac e b

e t i X X

ve s ( o 2.0 2.0 b a belo w

ATIO N s N r rs X X e e A

teville t e 1.5 1.5 me t me t

EXP L 2 2 Fa y

X X

3 ea r 1.2 1.2 5 2 n

t t n n e e X X ve r

i * R * 1.0 1.0 ite Se g m Seg m h W 0 0 0 0 0 0 0 0 0 0 80 0 60 0 40 0 20 0 8 6 4 2 X X

10.0 10.0 X X

5.0 5.0 X X

2.0 2.0 X X

1.5 1.5 X X

6 1 2 1.2 1.2

t t n n e e X X

* * 1.0 1.0 Seg m Se g m Average daily dissolved solids for the period January 2006 through December 2010 at 2 meters (m) below surface and m above bottom model segments 2, Average 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0

8 6 4 2 8 6 4 2

r e t i l r pe s m a r g i l l i m n i , on i t a r t n e conc

s d i l o s d lve o ss i d e g a r Ave Figure 18. 5, 14, 16, 23, and 35 from baseline model (loading factor 1.0) increased loading scenarios (1.2, 1.5, 2.0, 5.0, 10.0) White River near Fayetteville, Arkansas, (site (* Fayetteville wastewater treatment plant dissolved solids not included in CE-QUAL-W2 baseline calibration or any scenario runs.) S1) only. Dissolved Solids, Chloride, and Sulfate Fate and Transport Simulations 41 X X

10.0 10.0 X X

5.0 5.0 X X

2.0 2.0 X X

1.5 1.5 X X

4 5 1 3

1.2 1.2 t t n n e e X X

* * 1.0 1.0 Se g m Seg m 0 0 0 0 0 0 0 0 0 0 40 0 30 0 20 0 10 0 4 3 2 1 r o t fa c X X

g n i 10.0 10.0 m oa d l o

X X

t ) t 3 o 5.0 5.0 S surfac e

b

e t i ve s X X o

(

b a l e belo w 2.0 2.0

l ATIO N i s N v r rs e e A X X

nd s i me t me t 1.5 1.5 H

EXP L 2 2 r a e X X

n 3 1.2 1.2 2 5 ek

t t n n Cr e e X X e

* e * l 1.0 1.0 g a Se g m Seg m E

r a 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 3 2 1 4 3 2 1 W X X

10.0 10.0 X X

5.0 5.0 X X

2.0 2.0 X X

1.5 1.5 X X

8 6 1.2 1.2 1 4

t t n n e X X e

* * 1.0 1.0 Seg m Seg m Average daily dissolved solids for the period January 2006 through December 2010 at 2 meters (m) below surface and m above bottom model segments Average 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0

4 3 2 1 4 3 2 1

r e t i l r pe s m a r g i l l i m n i , on i t a r t n e conc

s d i l o s d lve o ss i d e g a r Ave Figure 19. Eagle Creek near Hindsville, Arkansas, 48, 5, 14, 16, 23, and 35 from baseline model (loading factor 1.0) increased loading scenarios (1.2, 1.5, 2.0, 5.0, 10.0) War (* Fayetteville wastewater treatment plant dissolved solids not included in CE-QUAL-W2 baseline calibration or any scenario runs.) (site S3) only. 42 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10 X X

10.0 10.0 X X

5.0 5.0 X X

2.0 2.0 X X

r o 1.5 1.5 t c a f

X X

g 5 4 n 3 i 1.2 1.2

1 t t d n n a e e o l

X X

t * * n 1.0 1.0 Seg m Se g m 0 0 0 0 0 0 ncurr e 0 0 0 0 o 80 0 60 0 40 0 20 0 8 6 4 2 c ) 3 S

e t i s (

e l l X X i

v 10.0 10.0 nd s i m H

o X X r

t t a o e 5.0 5.0 surfac e b n

ve X X o

b a belo w 2.0 2.0 Cr ee k

ATIO N

s e N r rs l e e A g X X a

E

me t me t 1.5 1.5 r

EXP L a 2 2 W X X

3 nd 5 2 1.2 1.2 a

t t ) n n 1 e e S X X

* e * t i 1.0 1.0 s ( Se g m Seg m

e l l i 0 0 0 0 0 0 v 0 0 0 0 e 80 0 60 0 40 0 20 0 8 6 4 2 t t e y a F

r a e n

X X r

e v i 10.0 10.0 R

e t i X X

h 5.0 5.0 W X X

2.0 2.0 X X

1.5 1.5 X X

6 1.2 1.2 1 2

t t n n e e X X

* * 1.0 1.0 Se g m Seg m Average daily dissolved solids for the period January 2006 through December 2010 at 2 meters below surface and above bottom model segments Average 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0

8 6 4 2 8 6 4 2

r e t i l r pe s m a r g i l l i m n i , on i t a r t n e conc

s d i l o s d lve o ss i d e g a r Ave Figure 20. 2, 5, 14, 16, 23, and 35 from baseline model (loading factor 1.0) increased loading scenarios (1.2, 1.5, 2.0, 5.0 , 10.0) both White River near Fayetteville, Eagle Creek near Hindsville, Ark. (site S3). (* Fayetteville wastewater treatment plant dissolved solids not included in CE-QUAL-W2 baseline Arkansas, (site S1) and War calibration or any scenario runs.) Dissolved Solids, Chloride, and Sulfate Fate and Transport Simulations 43 X X

10.0 10.0 X X

5.0 5.0 X X

2.0 2.0 X X

1.5 1.5 X X

4 5 1.2 1.2 1 3

t t n n e e X X

* * 1.0 1.0 Se g m Seg m 0 5 0 5 0 5 0 0 5 0 5 0 5 0 3 2 2 1 1 3 2 2 1 1 r o t X X fa c

g n i 10.0 10.0 d m o X X lo a

t

t ) o 1 5.0 5.0 surfac e b S

e t ve i X X o

s ( b

a belo w 2.0 2.0

ATIO N s ill e N r rs v e e A e X X t

t e me t me t 1.5 1.5

EXP L 2 2 Fa y

r X X

a 3 5 e 2

1.2 1.2 t t n

n n r e e e v X X i

R * *

1.0 1.0 e Seg m Seg m t i h W 0 5 0 5 0 5 0 0 5 0 5 0 5 0 3 2 2 1 1 3 2 2 1 1 X X

10.0 10.0 X X

5.0 5.0 X X

2.0 2.0 X X

1.5 1.5 X X

6 1 2 1.2 1.2

t t n n e e X X

* * 1.0 1.0 Seg m Se g m Average daily chloride concentrations for the period January 2006 through December 2010 at 2 meters below surface and above bottom model Average

0 5 0 5 0 5 0 0 5 0 5 0 5 0

3 2 2 1 1 3 2 2 1 1

r e t li r e p s m a r llig i m n i

, on i t a r t n e conc e d i or l ch e g a r e Av Figure 21. segments 2, 5, 14, 16, 23, and 35 from baseline model (loading factor 1.0) increased loading scenarios (1.2, 1.5, 2. 0, 5.0, 10.0) White River near Fayetteville, (* Fayetteville wastewater treatment plant chloride load not included in CE-QUAL-W2 baseline calibration or any scenario runs.) Arkansas, (site S1) only. 44 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10 X X

10.0 10.0 X X

5.0 5.0 X X

2.0 2.0 X X

1.5 1.5 X X

5 4 1.2 1 3 1.2

t t n n e e X X

m m * * g 1.0 1.0 Se Seg 5 0 5 5 0 5 0 5 0 0 5 0 1 1 1 1 2 2 2 2 r o t c a f

g X X

n i d a 10.0 10.0 e o m l ) o X X t

t o 5.0 5.0 e S3 surfac b

it N s w ve ( X X o

b lle i a belo ATIO 2.0 2.0

s N sv r rs A e e t t X nd X L

i H

me 1.5 me 1.5 r

EXP 2 2 a e n X X

3 ek 5 1.2 1.2 2

t t n n Cr e e e X X

m m le * * g 1.0 1.0 Seg Seg Ea r a 5 0 5 0 5 0 5 0 5 0 5 0 1 1 1 1 2 2 2 2 W X X

10.0 10.0 X X

5.0 5.0 X X

2.0 2.0 X X

1.5 1.5 X X

8 6 1.2 1 4 1.2

t t n n e e X X

m m * * g 1.0 1.0 Seg Se Average daily chloride concentrations for the period January 2006 through December 2010 at 2 meters below surface and above bottom model Average

5 0 5 0 5 0 5 0 5 0 5 0

1 1 1 1 2 2 2 2

r e t li r e p s m a r llig i m n i

, on i t a r t n e conc e d i or l ch e g a r e Av Figure 22. Eagle Creek near Hindsville, segments 48, 5, 14, 16, 23, and 35 from baseline model (loading factor 1.0) increased loading scenarios (1.2, 1.5, 2 .0, 5.0, 10.0) War (* Fayetteville wastewater treatment plant chloride load not included in CE-QUAL-W2 baseline calibration or any scenario runs.) Arkansas, (site S3) only. Dissolved Solids, Chloride, and Sulfate Fate and Transport Simulations 45 X X

10.0 10.0 X X

5.0 5.0 X X

2.0 2.0 X X

1.5 1.5 r o t c X X

5 a f 3

1 4 1.2 1.2 t t g n n n i e e X X m m

a d

g o * * l

1.0 1.0 t Seg Se n e 0 5 0 5 0 5 0 0 5 0 5 0 5 0 1 1 1 1 2 2 2 3 2 3 concurr ) 3 S

e t si X X (

e l l i 10.0 10.0 v e s m o X X t

nd t i o H 5.0 5.0

surfac b

r

a N w ve e X X o

n

b a belo 2.0 ATIO 2.0 ek

s N r rs A e e Cr e t t X

X L

e me 1.5 me gl 1.5

a EXP 2 2 E

r X X

3 a 5 2

1.2 W t t 1.2

n n e e nd a X m m X

) g * * 1.0 1.0 S1 Seg Se

ite s ( 0 5 0 5 0 5 0 0 5 0 5 0 5 0

1 1 1 1 2 2 2 2 3 3 eville tt e y Fa

r X X

a e n

10.0 10.0 r ve i X X

R

e 5.0 5.0 t i h X X

W 2.0 2.0 X X

1.5 1.5 X X

6 2 1

t 1.2 t 1.2 n n e e m m X X

g * * 1.0 1.0 Seg Se Average daily chloride concentrations for the period January 2006 through December 2010 at 2 meters below surface and above bottom Average

0 5 0 5 0 5 0 0 5 0 5 0 5 0

1 1 1 1 2 2 2 2 3 3

r e t li r e p s m a r llig i m n i

, on i t a r t n e conc e d i or l ch e g a r e Av Figure 23. model segments 2, 5, 14, 16, 23, and 35 from baseline (loading factor 1.0) increased loading scenarios (1.2, 1 .5, 2.0, 5.0, 10.0) both White River near Eagle Creek near Hindsville, Ark. (site S3). (* Fayetteville wastewater treatment plant chloride load not included in CE-QUAL-W2 Fayetteville, Arkansas, (site S1) and War baseline calibration or any scenario runs.) 46 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10 X X

10.0 10.0 X X

5.0 5.0 X X

2.0 2.0 X X

1.5 1.5 X X

5 4 3 1 1.2 1.2

t t n n e e X X

* * 1.0 1.0 Seg m Se g m 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 8 6 4 2 2 0 8 6 4 2 1 1 1 1 to r X X

g fa c n i 10.0 10.0 e m o oa d X X t l

t ) o 5.0 5.0 surfac b

N e S 1 w ve t i X X o

s ( b a belo ATIO 2.0 2.0

s N r rs A e e t t X X L

tevi ll e

t e me 1.5 me 1.5

EXP 2 2 Fa y r X X

3

a 5 2

e t t 1.2 1.2 n

n n e e ve r X X i

R * * 1.0 1.0 Se g m Seg m ite h W 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 8 6 4 2 2 0 8 6 4 2 1 1 1 1 X X

10.0 10.0 X X

5.0 5.0 X X

2.0 2.0 X X

1.5 1.5 X X

6 2 1

1.2 t t 1.2 n n e e X X

* * 1.0 1.0 Seg m Seg m Average daily sulfate concentrations for the period January 2006 through December 2010 at 2 meters below surface and above bottom model Average 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2 0 8 6 4 2 2 0 8 6 4 2

1 1 1 1

r e t i l r pe s m a r ig ill m n i

, on i t a r t n e conc e t a f l u s e g a r e v A Figure 24. segments 2, 5, 14, 16, 23, and 35 from baseline model (loading factor 1.0) increased loading scenarios (1.2, 1.5, 2. 0, 5.0, 10.0) White River near Fayetteville, (* Fayetteville wastewater treatment plant sulfate load not included in CE-QUAL-W2 baseline calibration or any scenario runs.) Arkansas, (site S1) only. Dissolved Solids, Chloride, and Sulfate Fate and Transport Simulations 47 X X

10.0 10.0 X X

5.0 5.0 X X

2.0 2.0 X X

1.5 1.5 X X

4 5 1 3

1.2 1.2 t t n n e e X X

* * 1.0 1.0 Se g m Seg m 5 0 5 0 5 0 5 0 5 0 5 0 2 2 1 1 2 2 1 1 r o t fa c

X X g

n i 10.0 10.0 e oa d m l

o ) X X t

3 t S o

5.0 5.0 surfac b e

t i N w s ve ( X X

o

b l e l a belo 2.0 ATIO i 2.0

v s N r rs A e e t t X X L nd s

i H

me 1.5 me 1.5

r EXP 2 2 a e X n X

3 2 5 ek 1.2

1.2 t t n n e e Cr e

X X

e l * * g 1.0 1.0 a Se g m Seg m E

r a 5 0 5 0 5 0 5 0 5 0 5 0 2 2 1 1 2 2 1 1 W X X

10.0 10.0 X X

5.0 5.0 X X

2.0 2.0 X X

1.5 1.5 X X

8 6 1.2 1.2 4 1

t t n n e e X X

* * 1.0 1.0 Se g m Seg m Average daily sulfate concentrations for the period January 2006 through December 2010 at 2 meters below surface and above bottom model Average 5 0 5 0 5 0 5 0 5 0 5 0

2 2 1 1 2 2 1 1

r e t i l r pe s m a r ig ill m n i

, on i t a r t n e conc e t a f l u s e g a r e v A Figure 25. Eagle Creek near Hindsville, segments 48, 5, 14, 16, 23, and 35 from baseline model (loading factor 1.0) increased loading scenarios (1.2, 1.5, 2 .0, 5.0, 10.0) War (* Fayetteville wastewater treatment plant sulfate load not included in CE-QUAL-W2 baseline calibration or any scenario runs.) Arkansas, (site S3) only. 48 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10 X X

10.0 10.0 X X

5.0 5.0 X X

2.0 2.0 X X

1.5 1.5 r o t c X X a

5 f

3

1 4 g 1.2 1.2 t t n n n i e e d a X X m m

o g l * *

t 1.0 1.0 n Seg Se e 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 8 2 2 6 8 0 6 4 4 ncurr 12 1 10 1 o ) c 3 S

e t si (

X X

e l l i v 10.0 10.0 e s m o nd X X t i

t H o

5.0 5.0 r surfac b

a N e w ve n X X o

b ek a belo ATIO 2.0 2.0

e s N r rs Cr A e e

t t X X L e

gl me 1.5 me 1.5 a

EXP 2 2 E

r a X X

3 5 2 W

1.2 1.2 t t n n nd e e a

X m X m )

g * * S1 1.0 1.0

Se Seg ite s (

0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 2 2 8 8 6 0 6 4 4 12 1 10 1 eville tt e y Fa

r X a X

e n

r 10.0 10.0 ve i X X R

e t 5.0 5.0 i h W X X

2.0 2.0 X X

1.5 1.5 X X

6 1 2 1.2 1.2

t t n n e e X X

m m * * g 1.0 1.0 Se Seg Average daily sulfate concentrations for the period January 2006 through December 2010 at 2 meters below surface and above bottom Average 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2 2 2 2 8 8 6 0 6 0 4 4

1 1 1 1

r e t i l r pe s m a r ig ill m n i

, on i t a r t n e conc e t a f l u s e g a r e v A Figure 26. model segments 2, 5, 14, 16, 23, and 35 from baseline (loading factor 1.0) increased loading scenarios (1.2, 1 .5, 2.0, 5.0, 10.0) both White River near Eagle Creek near Hindsville, Ark. (site S3). (* Fayetteville wastewater treatment plant sulfate load not included in CE-QUAL-W2 baseline Fayetteville, Arkansas, (site S1) and War calibration or any scenario runs.) Cited References 49

Summary Cited References

Beaver Lake is a large, deep-storage reservoir located Bales, J.D., Sarver, K.M., and Giorgino, M.J., 2001, Moun- in the upper White River Basin in northwestern Arkansas, tain Island Lake, North Carolina—Analysis of ambient and was completed in 1963 for the purposes of flood control, conditions and simulation of hydrodynamics, constituent hydroelectric power, and water supply. In addition, the transport, and water-quality characteristics, 1996-97: U.S. reservoir is used for fish and wildlife habitat, recreation, Geological Survey Water-Resources Investigations Report and waste assimilation. Beaver Lake is affected by point 01–4138, 85 p. and nonpoint sources of minerals, nutrients, and sediments. Cohn, T.A., 1995, Recent advances in statistical methods for The City of Fayetteville discharges about half of its sewage the estimation of sediment and nutrient transport in rivers, effluent into the White River immediately upstream from the U.S. National Report to the International Union Geodesy backwater of the reservoir. The City of West Fork discharges and Geophysics, 1991-1994: Reviews of Geophysics, its sewage effluent into the West Fork of the White River, and supplement 33, p. 1117–1123. the City of Huntsville discharges its sewage effluent into a tributary of War Eagle Creek. Cohn, T.A., Caulder, D.L., Gilroy, E.J., Zynjuk, L.D., and The purpose of this report is to describe the ambient Summers, R.M., 1992, The validity of a simple log-linear conditions and fate and transport of dissolved solids, chloride, model for estimating fluvial constituent loads—An empiri- and sulfate concentrations in Beaver Lake. Dissolved solids, cal study involving nutrient loads entering Chesapeake Bay: chloride, and sulfate are components of wastewater discharged Water Resources Research, v. 28, no. 9, p. 2353–2363. into Beaver Lake and a major concern of the drinking Cole, T.M., and Wells, S.A., 2003, CEQUAL-W2—A two water utilities that use Beaver Lake as their source. A two- dimensional, laterally averaged, hydrodynamic and water dimensional model of hydrodynamics and water quality was quality model, version 3.1: U.S. Army Corps of Engineers calibrated to include simulations of dissolved solids, chloride, Instruction Report EL–03–1 [variously paged]. and sulfate for the period January 2006 through December 2010. Estimated daily dissolved solids, chloride, and sulfate Fishman, M.J., 1993, Methods of analysis by the U.S. Geo- loads were increased in the White River and War Eagle Creek logical Survey National Water Quality Laboratory—Deter- mination of inorganic and organic constituents in water tributaries, individually and the two tributaries together, by and fluvial sediments: U.S. Geological Survey Open-File 1.2, 1.5, 2.0, 5.0, and 10.0 times the baseline conditions to Report 93–125, 217 p. examine fate and transport of these constituents through time at seven locations in the reservoir, from upstream to Galloway, J.M., and Green, W.R., 2002, Simulation of hydro- downstream in Beaver Lake. dynamics, temperature, and dissolved oxygen in Norfork Fifteen dissolved solids, chloride, and sulfate fate and Lake, Arkansas, 1994-1995: U.S. Geological Survey Water- transport scenarios were compared to the baseline simulation Resources Investigations Report 02–4250, 23 p. at each of the seven downstream locations in the reservoir, Galloway, J.M., and Green, W.R., 2003, Simulation of hydro- both 2 meters (m) below the surface and 2 m above the dynamics, temperature, and dissolved oxygen in Bull Shoals bottom. Concentrations were greater in the reservoir at model Lake, Arkansas, 1994-1995: U.S. Geological Survey Water- segments closer to where the tributaries entered the reservoir. Resources Investigations Report 03–4077, 23 p. Concentrations resulting from the increase in loading became more diluted farther downstream from the source. Differences Galloway, J.M, and Green, W.R. 2006, Analysis of ambient in concentrations between the baseline condition and the conditions and simulation of hydrodynamics and water- 1.2, 1.5, and 2.0 times baseline concentration scenarios were quality characteristics in Beaver Lake, Arkansas, 2001- smaller than the differences in the 5.0 and 10.0 times baseline 2003: U.S. Geological Survey Scientific Investigations concentration scenarios. The results for both the 2 m below Report 2006–5003, 55 p. the surface and 2 m above the bottom were similar, with the Green, W.R., Galloway, J.M., Richards, J.M., and Wesolowski, exception of concentrations resulting from the increased E.A., 2003, Simulation of hydrodynamics, temperature, and loading factors (5.0 and 10.0 times), where concentrations 2 dissolved oxygen in Table Rock Lake, Missouri, 1996-1997: m above the bottom were consistently greater than those 2 m U.S. Geological Survey Water-Resources Investigations below the surface at most segments. Report 03–4237, 35 p. 50 Ambient Conditions of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10

Haggard, B.E., and Green, W.R., 2002, Simulation of hydro- Wilde, F.D., and Radke, D.B., 1998, Field measurements: U.S. dynamics, temperature, and dissolved oxygen in Beaver Geological Survey Techniques of Water-Resources Investi- Lake, Arkansas, 1994-1995: U.S. Geological Survey Water- gations, book 9, chap. A6 [variously paged]. Resources Investigations Report 02–4116, 21 p. Wilde, F.D., Radke, D.B., Gibs, J., and Iwatsubo, R.T., 1998a, Marciano, J.J., and Harbeck, G.E., 1954, Mass-transfer stud- Preparations for water sampling: U.S. Geological Survey ies, in Water-loss investigations—Lake Hefner studies, Techniques of Water-Resources Investigations, book 9, technical report: U.S. Geological Survey Professional Paper chap. A1 [variously paged]. 269, p. 46–70. Wilde, F.D., Radke, D.B., Gibs, J., and Iwatsubo, R.T., 1998b, Rantz, S.E, and others, 1982, Measurement and computation Selection of equipment for water sampling: U.S. Geological of streamflow—Volume 1. Measurement of stage and dis- Survey Techniques of Water-Resources Investigations, book charge, Volume 2. Computation of discharge: U.S. Geologi- 9, chap. A2 [variously paged]. cal Survey Water-Supply Paper 2175, 631 p. Wilde, F.D., Radke, D.B., Gibs, J., and Iwatsubo, R.T., 1998c, Runkel, R.L., Crawford, C.G., and Cohn, T.A., 2004, Load Cleaning of equipment for water sampling: U.S. Geological estimator (LOADEST)—A FORTRAN program for Survey Techniques of Water-Resources Investigations, book estimating constituent loads in streams and rivers: U.S. Geological Survey Techniques and Methods, book 4, chap. 9, chap. A3 [variously paged]. A5, 69 p. Wilde, F.D., Radke, D.B., Gibs, J., and Iwatsubo, R.T., 1999a, Sullivan, A.B., and Rounds, S.A., 2005, Modeling hydro- Collection of water samples: U.S. Geological Survey Tech- dynamics, temperature, and water quality in Henry Hagg niques of Water-Resources Investigations, book 9, chap. A4 Lake, Oregon, 2000-03: U.S. Geological Survey Scientific [variously paged]. Investigations Report 2004–5261, 38 p. Wilde, F.D., Radke, D.B., Gibs, J., and Iwatsubo, R.T., 1999b, U.S. Army Corps of Engineers, 1997, Hydrologic engineering Processing of water samples: U.S. Geological Survey Tech- requirements for reservoirs: U.S. Army Corps of Engineers niques of Water-Resources Investigations, book 9, chap. A5 Engineering Manual 1110–2–1420 [variously paged]. [variously paged].

Publishing support provided by Lafayette Publishing Service Center Green—Ambient Conditions and Fate and Transport Simulations of Dissolved Solids, Chloride, and Sulfate in Beaver Lake, Arkansas, 2006–10—SIR 2013–5019