River

River

River

Provo

River

Jordan

River

Spanish

Fork

Utah

Lake

RANGE

Salt Lake City

Bear

Bear

River

Bear

Weber

Bear

Lake

WASATCH

IDAHO

WYOMING

Great

 Salt

 Lake

UTAH

Water-Resources Investigations Report 02–4276

U.S. Department of the Interior

U.S. Geological Survey

National Water-Quality Assessment Program

41∞

40∞

112∞

42∞

111∞

Strawberry

Reservoir

OQUIRRH MOUNTAINS

IDAHO WYOMING

UTAH

Salt

Lake

City

UINTA

MOUNTAINS

Hydrology and Water Quality of an Urban

Stream Reach in the Great Basin—Little

Cottonwood Creek near Salt Lake City, Utah,

Water Years 1999–2000
Hydrology and Water Quality of an Urban Stream 

Reach in the Great Basin—Little Cottonwood Creek 

near Salt Lake City, Utah, Water Years 1999-2000

NATIONAL WATER-QUALITY ASSESSMENT PROGRAM

By Steven J. Gerner and Kidd M. Waddell

Salt Lake City, Utah

2003

U.S. Geological Survey

Water-Resources Investigations Report 02-4276
U.S. DEPARTMENT OF THE INTERIOR

For additional information write to:

District Chief

U.S. Geological Survey

2329 West Orton Circle

Salt Lake City, Utah 84119

http://ut.water.usgs.gov

Copies of this report can be purchased from:

U.S. Geological Survey

Branch of Information Services

Building 810

Box 25286, Federal Center

Denver, CO 80225-0286

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. 

Government.

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

District Chief

U.S. Geological Survey

2329 Orton Circle

Salt Lake City, Utah 84119

http://ut.water.usgs.gov
Foreword iii

FOREWORD

The U.S. Geological Survey (USGS) is committed to serve the Nation with accurate and timely scientific 

information that helps enhance and protect the overall quality of life, and facilitates effective management of water, 

biological, energy, and mineral resources (http://www.usgs.gov/). Information on the quality of the Nation’s water 

resources is of critical interest to the USGS because it is so integrally linked to the long-term availability of water 

that is clean and safe for drinking and recreation and that is suitable for industry, irrigation, and habitat for fish and 

wildlife. Escalating population growth and increasing demands for the multiple water uses make water availability, 

now measured in terms of quantity and quality, even more critical to the long-term sustainability of our 

communities and ecosystems.

The USGS implemented the National Water-Quality Assessment (NAWQA) program to support national, 

regional, and local information needs and decisions related to water-quality management and policy 

(http://water.usgs.gov/nawqa). Shaped by and coordinated with ongoing efforts of other Federal, State, and local 

agencies, the NAWQA program is designed to answer: What is the condition of our Nation’s streams and ground 

water? How are the conditions changing over time? How do natural features and human activities affect the quality 

of streams and ground water, and where are those effects most pronounced? By combining information on water 

chemistry, physical characteristics, stream habitat, and aquatic life, the NAWQA program aims to provide sciencebased insights for current and emerging water issues and priorities. NAWQA results can contribute to informed 

decisions that result in practical and effective water-resource management and strategies that protect and restore 

water quality.

Since 1991, the NAWQA program has implemented interdisciplinary assessments in more than 50 of the 

Nation’s most important river basins and aquifers, referred to as Study Units (http://water.usgs.gov/nawqa/ 

nawqamap.html). Collectively, these Study Units account for more than 60 percent of the overall water use and 

population served by public water supply, and are representative of the Nation’s major hydrologic landscapes, 

priority ecological resources, and agricultural, urban, and natural sources of contamination. 

Each assessment is guided by a nationally consistent study design and methods of sampling and analysis. 

The assessments thereby build local knowledge about water-quality issues and trends in a particular stream or 

aquifer while providing an understanding of how and why water quality varies regionally and nationally. The 

consistent, multi-scale approach helps to determine if certain types of water-quality issues are isolated or pervasive, 

and allows direct comparisons of how human activities and natural processes affect water quality and ecological 

health in the Nation’s diverse geographic and environmental settings. Comprehensive assessments on pesticides, 

nutrients, volatile organic compounds, trace metals, and aquatic ecology are developed at the national scale through 

comparative analysis of the Study-Unit findings (http://water.usgs.gov/nawqa/natsyn.html). 

The USGS places high value on the communication and dissemination of credible, timely, and relevant 

science so that the most recent and available knowledge about water resources can be applied in management and 

policy decisions. We hope this NAWQA publication will provide you the needed insights and information to meet 

your needs, and thereby foster increased awareness and involvement in the protection and restoration of our 

Nation’s waters. 

The NAWQA program recognizes that a national assessment by a single program cannot address all waterresource issues of interest. External coordination at all levels is critical for a fully integrated understanding of 

watersheds and for cost-effective management, regulation, and conservation of our Nation’s water resources. The 

program, therefore, depends extensively on the advice, cooperation, and information from other Federal, State, 

interstate, Tribal, and local agencies, non-government organizations, industry, academia, and other stakeholder 

groups. The assistance and suggestions of all are greatly appreciated.

Robert M. Hirsch

Associate Director for Water
iv Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah
iv Contents

CONTENTS

Foreword .............................................................................................................................................................. iii

Abstract ................................................................................................................................................................ 1

Introduction .......................................................................................................................................................... 2

Purpose and Scope ...................................................................................................................................... 2

Description of Study Area........................................................................................................................... 3

Land Use and Urbanization................................................................................................................ 3

Stream Classification ......................................................................................................................... 8

Methods of Sample Collection and Data Analysis............................................................................................... 8

Hydrology............................................................................................................................................................. 9

Stream Characteristics................................................................................................................................. 9

Streamflow Components............................................................................................................................. 9

Water Quality ....................................................................................................................................................... 10

Properties..................................................................................................................................................... 11

Major Ions ................................................................................................................................................... 13

Nutrients...................................................................................................................................................... 19

Trace Elements............................................................................................................................................ 22

Pesticides..................................................................................................................................................... 24

Volatile Organic Compounds...................................................................................................................... 29

Effect of Storms .......................................................................................................................................... 29

Spring and Summer............................................................................................................................ 29

Winter................................................................................................................................................. 32

Summary .............................................................................................................................................................. 38

References Cited .................................................................................................................................................. 41

Appendix .............................................................................................................................................................. 43

Quality-Control Procedures and Results .............................................................................................................. 43
Contents v

FIGURES

Figure 1. Map showing location of study area, fixed sites, historic‘ smelter sites, and photographs 

showing area near fixed sites 1 and 2, and headwaters of Little Cottonwood Creek in Albion 

Basin, near Salt Lake City, Utah........................................................................................................ 4

Figure 2. Map showing location of sample sites, Little Cottonwood Creek, near Salt Lake City, Utah, 

August 31 and September 2, 1999 ..................................................................................................... 6

Figure 3. Map showing land use/cover of Little Cottonwood Creek drainage basin, near Salt Lake 

City, Utah........................................................................................................................................... 7

Figure 4. Graph showing streamflow between sites 1 and 2, Little Cottonwood Creek, near Salt Lake 

City, Utah, August 31 and September 2, 1999 .................................................................................. 11

Figure 5. Graph showing daily mean streamflow and temporal distribution of water-quality samples at 

sites 1 and 2 on Little Cottonwood Creek, near Salt Lake City, Utah............................................... 12

Figure 6. Graph showing monthly streamflow at sites 1 and 2 on Little Cottonwood Creek, near Salt 

Lake City, Utah.................................................................................................................................. 13

Figure 7. Graphs showing daily mean streamflow and specific conductance at sites 1 and 2 on Little 

Cottonwood Creek, near Salt Lake City, Utah .................................................................................. 16

Figure 8. Graphs showing relation of chloride and sodium concentration to specific conductance at sites 1 

and 2 on Little Cottonwood Creek, near Salt Lake City, Utah.......................................................... 17

Figure 9. Boxplots showing (A) dissolved oxygen, in percent saturation, (B) dissolved-oxygen 

concentration, and (C) pH at sites 1 and 2 on Little Cottonwood Creek, near Salt Lake City, 

Utah, 1999-2000 water years ............................................................................................................. 17

Figure 10. Graphs showing cumulative frequency curves of daily mean water temperature for sites 1 

and 2 on Little Cottonwood Creek, near Salt Lake City, Utah, 1999-2000 water years, and 

water temperature on August 1, 1999, and April 1, 2000, at sites 1 and 2........................................ 18

Figure 11. Graphs showing chemical composition of streamflow at sites 1 and 2 on Little Cottonwood 

Creek, near Salt Lake City, Utah, 1999 water year ........................................................................... 19

Figure 12. Trilinear diagram showing composition of water samples collected from sites 1, S6, S8, and 2 

on Little Cottonwood Creek, near Salt Lake City, Utah.................................................................... 20

Figure 13. Graphs showing relation of concentration of total phosphorus and dissolved nitrite plus 

nitrate to streamflow at sites 1 and 2, Little Cottonwood Creek, near Salt Lake City, Utah............. 22

Figure 14. Graph showing relation of concentration of suspended sediment to total phosphorus in 

samples from sites 1 and 2, Little Cottonwood Creek, near Salt Lake City, Utah ............................ 23

Figure 15. Boxplot showing percentage of phosphorus in the suspended phase in samples from sites 1 

and 2, Little Cottonwood Creek, near Salt Lake City, Utah.............................................................. 24

Figure 16. Graphs showing relation of concentration of arsenic and copper to streamflow at sites 1 and 2 

on Little Cottonwood Creek, near Salt Lake City, Utah.................................................................... 26

Figure 17. Graph showing concentration of arsenic, copper, and zinc in water collected from Little 

Cottonwood Creek, near Salt Lake City, Utah, August 31 and September 2, 1999.......................... 27

Figure 18. Graphs showing seasonal variability of selected pesticide concentrations at site 2 on Little 

Cottonwood Creek, near Salt Lake City, Utah .................................................................................. 31

Figure 19. Graph showing concentration of selected pesticides at sites 1 and S6 on Little Cottonwood 

Creek, September 2, 1999, and sites S8 and 2 on Little Cottonwood Creek, near Salt Lake City, 

Utah, August 31, 1999 ....................................................................................................................... 32
Contents vi

Figure 20. Graphs showing relation of number of volatile organic compounds detected to (A) dissolved 

organic carbon, (B) water temperature, and (C) seasonal streamflow at site 2 on Little 

Cottonwood Creek, near Salt Lake City, Utah .................................................................................. 36

Figure 21. Hydrograph showing streamflow and temporal distribution of water-quality samples at sites 1 

and 2 on Little Cottonwood Creek, near Salt Lake City, Utah, during storm on April 14, 2000...... 38

Figure 22. Graph showing relation of mean concentration of (A) total ammonia plus organic nitrogen, 

total nitrogen, and total phosphorus, and (B) atrazine, carbaryl, diazinon, and prometon at sites 1 

and 2, and in runoff between sites 1 and 2 in non-storm and storm samples, Little Cottonwood 

Creek, near Salt Lake City, Utah ....................................................................................................... 39
Contents vii

TABLES

Table 1. Minimum reporting level of parameters and constituents measured at fixed sites on Little 

Cottonwood Creek, near Salt Lake City, Utah ................................................................................. 14

Table 2. Summary of nutrient concentration in water samples collected from sites 1 and 2 on Little 

Cottonwood Creek, near Salt Lake City, Utah ................................................................................. 21

Table 3. Summary of trace-element concentration in water samples collected from sites 1 and 2 on 

Little Cottonwood Creek, near Salt Lake City, Utah ........................................................................ 25

Table 4. Minimum reporting level of pesticides analyzed for in water samples collected at fixed sites 

on Little Cottonwood Creek, near Salt Lake City, Utah ................................................................... 28

Table 5. Summary of pesticides analyzed for by gas chromatography/mass spectrometry and detected 

in water samples collected from sites 1 and 2 on Little Cottonwood Creek, near Salt Lake 

City, Utah .......................................................................................................................................... 30

Table 6. Minimum reporting level of volatile organic compounds analyzed for in water samples 

collected at fixed sites on Little Cottonwood Creek, near Salt Lake City, Utah .............................. 33

Table 7. Summary of volatile organic compounds detected in water samples from sites 1 and 2 on 

Little Cottonwood Creek, near Salt Lake City, Utah ........................................................................ 35

Table 8. Load and mean concentration of selected constituents at sites 1 and 2, and in runoff between 

sites 1 and 2, on Little Cottonwood Creek, near Salt Lake City, Utah, calculated for a storm 

on April 14, 2000 .............................................................................................................................. 37

Table 9. Summary of constituents detected in field blanks collected from basic fixed sites in the Great 

Salt Lake Basins study unit ............................................................................................................... 45

Table 10. Summary of surrogate and field matrix spike recovery in water samples collected from basic 

fixed sites in the Great Salt Lake Basins study unit ......................................................................... 45

Table 11. Summary of relative percent difference between constituents detected in split replicate sample 

pairs collected from fixed sites in the Great Salt Lake Basins study unit ......................................... 46
viii Conversion Factors

CONVERSION FACTORS, DATUMS, AND ABBREVIATED WATER-QUALITY UNITS

Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 

(NGVD 1929). Horizontal coordinate information is referenced to the North American Datum of 1983 

(NAD 83).

Chemical concentration and water temperature are reported only in metric units. Chemical concentration is reported in milligrams per liter (mg/L) or micrograms per liter (μg/L). Milligrams per liter is a 

unit expressing the solute per unit volume (liter) of water. One thousand micrograms per liter is equivalent to 1 milligram per liter. For concentrations less than 7,000 milligrams per liter, the numerical 

value is about the same as for concentrations in parts per million. Chemical load is a product of chemical concentration and streamflow and is reported in kilograms (kg) and grams (g). Specific conductance is reported in microsiemens per centimeter at 25 degrees Celsius (μS/cm). 

Water year is the 12-month period from October 1 through September 30. The water year is designated by the calendar year in which it ends. Thus, the 12-month period ending September 30, 1999, is 

water year 1999.

Multiply By To obtain

acre-foot (acre-ft) 1,233 cubic meter

cubic foot per second (ft3/s) 0.02832 cubic meter per second

foot (ft) 0.3048 meter

inch (in.) 25.4 millimeter

mile (mi) 1.609 kilometer

square mile (mi2) 2.590 square kilometer

Water temperature is reported in degrees Celsius (oC), which can be converted to 

degrees Fahrenheit (oF) by the following equation: oF = 1.8(oC)+32.
Abstract 1

ABSTRACT

The hydrology and water quality of an 

urbanized reach of Little Cottonwood Creek near 

Salt Lake City, Utah, were examined as part of the 

Great Salt Lake Basins study, part of the U.S. 

Geological Survey National Water-Quality 

Assessment program. Physical and chemical 

properties of the stream were referenced to 

established aquatic-life criteria as available. Two 

fixed sampling sites were established on Little 

Cottonwood Creek with the purpose of 

determining the influence of urbanization on the 

water quality of the stream. The fixed-site 

assessment is a component of the National WaterQuality Assessment surface-water study design 

used to assess the spatial and temporal distribution 

of selected water-quality constituents.

The occurrence and distribution of major 

ions, nutrients, trace elements, dissolved and 

suspended organic carbon, pesticides, volatile 

organic compounds, and suspended sediment were 

monitored during this study. From October 1998 to 

September 2000, stream samples were collected at 

regular intervals at the two fixed sites. Additional 

samples were collected at these sites during 

periods of high flow, which included runoff from 

snowmelt in the headwaters and seasonal 

thunderstorms in the lower basin. 

Arsenic was detected in 16 of 25 samples 

from site 1 in concentrations ranging from 0.7 to 

7.5 micrograms per liter (μg/L). Arsenic was 

detected in all 49 samples collected from site 2, 

with concentrations ranging from 4.7 to 284 μg/L. 

Surface runoff and sub-surface drainage near 

smelter tailings are likely sources of arsenic 

solutes. The U.S. Environmental Protection 

Agency aquatic-life criterion of 150 μg/L was 

exceeded in 8 of 49 samples at site 2.

Several pesticides were detected in more 

than 40 percent of the samples from sites 1 and 2. 

Prometon was the most frequently detected 

pesticide and was measured at higher 

concentrations than any other detected pesticide. 

Maximum measured prometon concentration was 

0.98 μg/L at site 1 and 5.61 μg/L at site 2.

Samples collected for volatile organic 

compounds at sites 1 and 2 were analyzed for 86 

compounds. At site 2, 28 compounds were 

detected. Toluene was detected at site 2 at a 

maximum concentration of 3.15 μg/L, which 

exceeded the aquatic-life criterion of 2 μg/L.

Runoff from urban land cover is a 

substantial source of nutrients and pesticides to 

Little Cottonwood Creek. Nutrient concentrations 

calculated in runoff to the stream between sites 1 

and 2 during a storm on April 14, 2000, were 

generally much higher than the mean 

concentration calculated for the storm at either site 

1 or 2. Atrazine, carbaryl, dacthal, and prometon 

concentrations calculated for inflow between sites 

1 and 2 during the storm were more than twice the 

mean concentration calculated for the storm at site 

1 and more than 30 percent higher than the mean 

concentration at site 2.

Specific-conductance values and chloride 

concentration increased in the urbanized reach of 

Little Cottonwood Creek during and following 

most winter storms. These increases were likely 

the result of road salting. The U.S. Environmental 

Protection Agency has recommended that the 

concentration of chloride not exceed 860 mg/L for 

more than 1 hour every 3 years or exceed a 4-day 

Hydrology and Water Quality of an Urban Stream Reach 

in the Great Basin—Little Cottonwood Creek near Salt 

Lake City, Utah, Water Years 1999-2000

By Steven J. Gerner and Kidd M. Waddell
2 Hydrology and Water Quality of Little Cottonwood Creek, Utah

average concentration of 230 mg/L more than once 

every 3 years. Estimates of chloride concentration 

determined from specific-conductance values 

indicate that chloride concentrations at site 2 

exceeded 860 mg/L about 9 percent of the time 

during December through March and exceeded a 

4-day average of 230 mg/L more than 30 times 

during the study period. A higher percentage of 

algae was identified in taxa more tolerant of 

salinity in samples from site 2 than from site 1, 

most likely because water with a higher salinity 

enters the stream between sites 1 and 2. 

INTRODUCTION

The National Water-Quality Assessment 

(NAWQA) program of the U.S. Geological Survey 

(USGS) began full-scale implementation in 1991. The 

objectives of the NAWQA program are to describe the 

status of and trends in the quality of the Nation's 

ground-water and surface-water resources as well as 

develop an understanding of the natural and human 

factors affecting those resources (Gilliom and others, 

1995). The Great Salt Lake Basins study unit in Utah, 

Idaho, and Wyoming (fig. 1) is 1 of 51 study units that 

are included in this national program. The 

environmental setting and description of the Great Salt 

Lake Basins study unit are presented in Baskin and 

others (2002). The fixed-site assessment is a 

component of the NAWQA surface-water study design 

used to assess the spatial and temporal distribution of 

selected water-quality constituents. Fixed sites are 

those locations on a stream where water samples are 

collected at a fixed frequency and a continuous record 

of streamflow is available. Sites are chosen to represent 

specific environmental settings, such as agricultural 

land or urban land, or to represent integration of 

multiple land uses. The latter sites are most often 

located at the major nodes in a drainage system. 

Two fixed sites were established on Little 

Cottonwood Creek, a tributary to the Jordan River, with 

the purpose of determining the influence of urban land 

uses on the water quality of the stream. Site 1, Little 

Cottonwood Creek at Crestwood Park, is about 4 mi 

downstream of the mouth of Little Cottonwood Canyon 

and was established to provide a baseline for evaluating 

the influence of the urban area on water quality (fixed 

site 1, fig. 1). Site 2, Little Cottonwood Creek at Jordan 

River, is about 0.7 mi above the confluence with the 

Jordan River and was established in conjunction with 

site 1 to determine the effects of urbanization on water 

quality in the stream reach between sites 1 and 2 (fixed 

site 2, fig. 1). The distance between sites 1 and 2 is 

about 5.7 mi. and the basin area between the sites is 

nearly 100 percent urban land cover. 

Data for this study were collected from October 

1998 through September 2000, encompassing the 1999 

and 2000 water years. A synoptic study, a short-term 

investigation of water quality used to provide improved 

spatial coverage for selected water-quality conditions, 

was conducted in August and September 1999 and 

provided additional information on occurrence and 

spatial distribution of nutrients, trace metals, and 

pesticides during low flow periods in the reach between 

sites 1 and 2.

This synoptic study included a tracer-injection 

study conducted in the Little Cottonwood Creek reach 

between sites 1 and 2 to determine areas of groundwater discharge and identify areas where solutes may 

be entering the stream. Increases in stream solute loads 

or streamflow where no inflows are visible can indicate 

an area where ground water is discharging to the 

stream. Water samples for the tracer-injection study 

were collected from the sites shown in figure 2. 

Water-quality issues of particular importance in 

the urban reach of Little Cottonwood Creek include 

constituents in storm-water runoff, trace metals 

entering the stream near historic ore smelting sites, and 

elevated chloride and sodium concentrations most 

likely caused by road salting. 

Purpose and Scope

This report (1) describes the stream hydrology 

and water quality in an urban reach of Little 

Cottonwood Creek from October 1, 1998, to September 

30, 2000, (2) relates changes in water quality to 

constituent sources, and (3) relates constituent 

concentrations to established aquatic-life criteria. The 

occurrence and distribution of major ions, nutrients, 

trace metals, dissolved and suspended organic carbons, 

pesticides, volatile organic compounds, and suspended 

sediment are reported. 

Data used in this report are available in the 

National Water Information System (NWIS) database 

and the NAWQA Data Warehouse maintained by the 

USGS. This database is subject to periodic review and 
Introduction 3

possible revision. Major ion, nutrient, trace metal, 

dissolved and suspended organic carbon, and sediment 

data also are available in USGS Water-Data Reports 

(Herbert and others, 2000, 2001, and 2002).

Description of Study Area

Little Cottonwood Creek flows west out of the 

Wasatch Mountains and across Salt Lake Valley to the 

Jordan River. The headwaters of Little Cottonwood 

Creek are in Little Cottonwood Canyon, a glaciated 

canyon in Wasatch-Cache National Forest and the 

Wasatch and Uinta Mountains eco-region (Woods and 

others, 2001). The entire Little Cottonwood Creek 

drainage basin encompasses 46 mi2, ranging in altitude 

from about 4,490 to 11,500 ft. The Little Cottonwood 

Creek urban land-use study area encompasses the Little 

Cottonwood Creek drainage basin from the canyon 

mouth to the confluence with the Jordan River (fig. 1). 

The study area is about 13.3 mi2, ranges in altitude 

from 4,490 to 5,810 ft, and lies in Salt Lake Valley and 

in the Central Basin and Range eco-region (Woods and 

others, 2001). 

Land Use and Urbanization 

The reach of Little Cottonwood Creek used for 

the urban land-use study extends across several 

communities, each of which was established as a 

separate town site and later grew to include residential 

areas extending to adjacent community boundaries. 

These communities were founded soon after pioneer 

settlement of Salt Lake Valley in 1847 and supported 

agricultural activities. Following the discovery of gold, 

silver, copper, and lead in nearby canyons in the 1870s, 

ore-refining activities brought an influx of people to 

these communities. During the mid- to late 1900s, 

residential land use replaced agriculture as the 

dominant land-use type in the lower Little Cottonwood 

Creek drainage basin as the population of Salt Lake 

Valley expanded. 

Land cover upstream from the mouth of Little 

Cottonwood Canyon is 60 percent forest land and 33 

percent rangeland (fig. 3). The watershed in Little 

Cottonwood Canyon is protected as a drinking water 

source but receives extensive recreational use. The 

urbanized part of the Little Cottonwood Creek drainage 

basin includes that part from the mouth of Little 

Cottonwood Canyon to the confluence with the Jordan 

River. Land use in the valley and urbanized area of the 

Little Cottonwood Creek drainage basin was remapped 

for this report. The system of land-use classification 

used throughout this report is described by Anderson 

and others (1976).

Residential land use accounts for 52 percent of 

land use in the urbanized area of the Little Cottonwood 

Creek drainage basin. Vegetative cover accounts for 21 

percent of the land use in the urban drainage, followed 

by roads and utilities that account for 15 percent. 

Commercial and municipal structures account for 8 

percent, and golf courses, water, and barren ground 

account for the remaining 3 percent. Low-density 

residential housing, consisting mostly of single-family 

dwellings, accounts for 96 percent of the residential 

land use.

The first legitimate mining operation in Little 

Cottonwood Canyon was established in 1865 (Calkins, 

1943). The ore deposits in Little Cottonwood Canyon 

yielded principally silver and lead with some copper, 

gold, and zinc. These ore deposits were formed mainly 

in shale, limestone, and dolomite. Galena or lead 

sulfide was the common primary lead mineral of the 

area. Argentite was found in most of the primary ores 

and was probably an abundant primary silver mineral. 

Ore production varied with time because of the nature 

of the deposits and the scattered control of holdings. 

The 1870s were especially productive, when rich 

deposits were mined.

A number of smelters operated along Little 

Cottonwood Creek during the 1870s. The Davenport 

and Flagstaff silver and lead smelters were located at 

the mouth of Little Cottonwood Canyon (fig. 1) and 

were operated from 1872 to 1875. Because of the 

technology employed during this period of smelter 

operation, as much as half the lead was lost to slag or 

emitted from the low stacks. Several other smelters 

began operating in the 1870s farther downstream, near 

site 2. The Germania smelter was built in 1872 and 

operated until 1902, when the Murray Smelter replaced 

it, operating until 1949. Smelting operations produced 

a variety of by-products that included arsenic, matte, 

arsenical speiss, and slag (U.S. Environmental 

Protection Agency, 1998a).
4 Hydrology and Water Quality of Little Cottonwood Creek, Utah

Figure 1. Location of study area, fixed sites, historic smelter sites, and photographs showing area near fixed sites 1 and 2, and headwaters of Little 

Cottonwood Creek in Albion Basin, near Salt Lake City, Utah.

Salt Lake Valley

Jordan River

Jordan Canal

Salt Lake and

Jordan

Canal

East

WASATCH

MOUNTAINS

Little Cottonwood Canyon

Cottonwood Creek Little

2

Albion Basin

Power plant

diversion

Metropolitan

Water Treatment Plant

Tower diversion

Cottonwood Weir

15

215

Base from U.S. Geological Survey digital line graph data, 1:100,000 scale, 1999,

Universal Transverse Mercator projection, Zone 12

National Elevation Data set 1:24,000 scale, 1999 2 4 5 KILOMETERS

0 1 3 5 MILES

01 3

2 4

1

S6

2 1

3

4

5

6

40r39"15' 40r34"

111r36"15'

111r53"

S8

Utah

Lake

East

Canyon

Reservoir

Pine View

Reservoir

Echo

Reservoir

Bear

River

River

Deer Creek

Reservoir

Mona

Reservoir

0 20 40 60 KILOMETERS

0 20 40 60 MILES

40r

41r

42r

112r 111r

Great

 Salt

 Lake

Provo

River

Jordan

River

Provo

Bear

Lake

UTAH

IDAHO

Bear

Woodruff

Narrows

Malad

Rockport

Reservoir

Evanston Ogden

Jordanelle

Reservoir

Study

area

Great Salt Lake

Basins NAWQA

study unit

River

Salt

Lake

City

Weber River Willard

Bay

WYOMING
Introduction 5

Figure 1. Location of study area, fixed sites, historic smelter sites, and photographs showing area near fixed sites 1 and 2, and headwaters of Little 

Cottonwood Creek in Albion Basin, near Salt Lake City, Utah—Continued.

Boundary of Little Cottonwood Creek drainage basin

Urbanized area

Non-urban area

Fixed site

1 Little Cottonwood Creek at Crestwood Park

2 Little Cottonwood Creek at Jordan River

Synoptic site

Hydrologic feature

Historic smelter site—Approximate location

1 Davenport

2 Flagstaff

3 Murray

4 Germania

5 Wasatch silver-lead works

6 Silver

EXPLANATION

Albion Basin

Little Cottonwood Creek, near site 1

Photograph by Heidi Hadley

Photograph by Jay Cederberg Photograph by Sandra Bray

S6

1

2

Little Cottonwood Creek, near site 2
6 Hydrology and Water Quality of Little Cottonwood Creek, Utah

Figure 2. Location of sample sites, Little Cottonwood Creek, near Salt Lake City, Utah, August 31 and September 2, 1999. 

S21

S20

S19

S18

Vine Street

S17

S16

S15

1300 East

S14

S13

S12

S11

900 East

S10

S9 S8

S7

S6

S4

S5

S3

S2

S1 1

2

5300 South

15

State Street

215

40°37"45'

40°36"15'

111°54"30'

Jordan

Canal

Salt

Lake

and

Jordan

Canal

East

111°51"30'

2 KILOMETERS

0 1 2 MILES

0 1

Fixed site—Number is site designation

Main stem site

Main stem site with additional tracemetal sample—Number is site designation

Tributary site

2

S19

EXPLANATION
Introduction 7

Figure 3. Land use/cover of Little Cottonwood Creek drainage basin, near Salt Lake City, Utah.

Lower (urbanized) basin

Low density residential

High density residential

Commercial/Municipal

Transportation/Utilities

Grass/Shrub/Forest

Golf course

Water

Barren/Other

Upper basin

Rangeland

Forest land

Barren land

Tundra

0 2 MILES

0 2 KILOMETERS

1

1

Barren land

2%

Tundra

 5%

Forest land

60%

Rangeland

33%

Barren/Other

1.4%

High density

residential

2.2%

Commercial/

Municipal

8.3%

Water

0.1%

Golf course

1.7%

Low density

residential

49.5%

Grass/

Shrub/

Forest

21.4%

Transportation/

Utilities

15.4%

EXPLANATION

Lower part of

basin

(urbanized)

Upper part

of basin

Photograph by Jay Cederberg
8 Hydrology and Water Quality of Little Cottonwood Creek, Utah

Past mining activities and ore-smelting 

operations continue to influence the water chemistry of 

the stream. Mine and smelter tailings in the Little 

Cottonwood Creek drainage basin can contribute trace 

metals to the stream. Metals from tailings can be 

transported by surface runoff and ground-water 

infiltration to the stream. Metals from fluvial tailings 

deposits in the stream can be resuspended and 

dissolved in the stream. 

Stream Classification

The Utah Division of Water Quality classifies 

water bodies in Utah as to type of water use to protect 

against controllable pollution (Utah Department of 

Environmental Quality, 1997). From the headwaters in 

Albion Basin to the Metropolitan Water Treatment 

Plant (fig. 1) near the mouth of the canyon, Little 

Cottonwood Creek is designated for the beneficial uses 

of treated drinking water (Class 1C), secondary contact 

recreation (Class 2B), and cold water aquatic-life 

support (Class 3A). Below the Metropolitan Water 

Treatment Plant to the confluence with the Jordan 

River, including the urban land-use study reach, Little 

Cottonwood Creek is designated for the beneficial uses 

of secondary contact recreation (Class 2B), cold water 

aquatic-life support (Class 3A), and agricultural uses 

(Class 4).

METHODS OF SAMPLE COLLECTION AND 

DATA ANALYSIS

Monthly samples were collected at sites 1 and 2 

during the 1999 and 2000 water years. Weekly to 

biweekly samples were collected at site 2 from March 

1999 to August 1999. Additional samples were 

collected at these sites during extreme flow and during 

synoptic studies. During each site visit, field 

measurements of specific conductance, water 

temperature, pH, dissolved oxygen, and alkalinity were 

made. Samples were analyzed at the USGS National 

Water Quality Laboratory in Denver, Colorado.

Discrete fixed-interval and most high-flow water 

samples were obtained for analysis of most 

constituents by collecting and compositing depthintegrated subsamples at equal-width increments or 

equal-discharge increments across the stream channel 

by using either a US DH-81 or a US D-95 sampler 

(Edwards and Glysson, 1988; Shelton, 1994). 

Conditions of low velocity and/or shallow depths 

required that some samples be collected with a 

weighted open bottle. Organic carbon samples were 

collected separately in a baked amber glass bottle by 

using a weighted sampler at a single midstream vertical 

(Shelton, 1994). Volatile organic compound (VOC) 

samples were collected with a specially designed 

Wildco sampler, into which 40-milliliter (ml) vials 

were placed directly to collect a sample at a single 

point in the stream (Shelton, 1997).

Samples were composited and split into equal 

subsamples with a Teflon cone splitter, except for those 

samples analyzed for organic carbon and VOCs, which 

were collected separately. Samples were processed in 

the field immediately after collection to reduce the 

chance of chemical or biological alteration. Major 

cation and anion, dissolved nutrient, and dissolved 

trace-element samples were filtered through a Gelman 

capsule filter with 0.45-micrometer (μm) pore size, and 

pesticide samples were filtered through a baked glass 

fiber filter with 0.70-μm pore size. Suspended and 

dissolved organic carbon samples were filtered through 

a silver filter with 0.45-μm pore size (Shelton, 1994). 

Major cation samples were preserved with nitric acid 

(HNO3), whole water nutrient samples were chilled or 

preserved with sulfuric acid (H2SO4), VOC samples 

were preserved with concentrated hydrochloric acid. 

The equipment was cleaned between sites as described 

in Shelton (1994, 1997).

The minimum reporting level (MRL) is the 

smallest measured concentration of a constituent that 

may be reliably reported when using a given analytical 

method. Concentrations are reported as less than the 

MRL for samples in which the analyte either was not 

detected or was detected at a concentration less than 

the MRL. Analytes that are detected at concentrations 

between the long-term method detection level and 

MRL are estimated. Estimated concentrations are noted 

with a remark code of “e.” These data should be used 

with the understanding that their uncertainty is greater 

than that of data reported without the “e” remark code. 

Nine water samples from site 1 and 42 water 

samples from site 2 were analyzed for pesticides by 

using gas chromatography/mass spectrometry 

(GC/MS). Four water samples from site 1 and 24 water 

samples from site 2 were analyzed for pesticides by 

using high-performance liquid chromatography/mass 

spectrometry (HPLC/MS). The HPLC/MS method was 

a custom method being validated at the USGS National 

Water-Quality Laboratory concurrently with analysis 
Hydrology 9

of water samples collected for this study. The 

HPLC/MS method was still being proven at the time of 

sample analysis and data from these analyses will 

remain provisional. Pesticides detected in water 

samples analyzed by HPLC/MS are reported; however, 

no concentrations or descriptive statistics associated 

with detected analytes are reported. Most of the 

samples analyzed by HPLC/MS were held for an 

extended period beyond the normal limit of 4 days. 

This may have resulted in degradation of some 

compounds initially present in the water samples to a 

concentration below the method reporting level.

The MRL of an analyte can be the largest 

influence on the detection frequency of that analyte. A 

common reporting limit of 0.01 μg/L was used to 

compare the detection frequencies of pesticides with 

different MRLs. Pesticide frequency analysis censored 

detections less than 0.01 μg/L, resulting in a slight loss 

of detection information; however, with a common 

reporting limit, a more uniform comparison of 

detection frequencies is possible. Pesticide data, at the 

original MRL, were used in other statistical analyses. 

The same method was applied to VOC data by using a 

common reporting limit of 0.05 μg/L. Estimated values 

were included in all data analysis.

Constituent loads and concentrations in the study 

reach, associated with a storm on April 14, 2000, were 

estimated by using discharge calculated from stage 

records and constituent concentrations from storm 

samples. Load calculations were based on the midinterval method described in Techniques of WaterResources Investigations of the United States 

Geological Survey, Book 3, Chapter C3 (Porterfield, 

1972). Concentrations associated with the beginning 

and ending point of the storm hydrograph were 

estimated from adjacent samples and used for 

calculating loads associated with the first and last 

interval of the storm hydrograph.

HYDROLOGY 

The hydrology of Little Cottonwood Creek is 

typical of that of many urban streams along the 

Wasatch Front and in the Intermountain West. A 

system of diversions for withdrawal of irrigation water 

began to be developed on many Wasatch Front streams 

soon after settlers arrived in Salt Lake Valley in 1847. 

As the population of the Wasatch Front increased, more 

of the water in valley streams was needed for drinking 

and domestic purposes. To meet domestic needs, water 

is withdrawn from several Wasatch Front streams, 

including Little Cottonwood Creek, as they emerge 

from headwater canyons and enter Salt Lake Valley. 

The water needs of irrigators downstream from the 

canyon mouths are satisfied with water diverted out of 

the Jordan River and transported across the valley in a 

system of canals. Some of the water from the Jordan 

River is imported to the urbanized reach of Little 

Cottonwood Creek. This water-distribution system 

continues to be monitored and updated, and the 

resulting hydrologic system is highly variable and 

complex. 

Stream Characteristics

In the vicinity of site 1 on Little Cottonwood 

Creek, the stream gradient is fairly steep, about 2 

percent. Cobbles and boulders are the dominant 

substrates with riffles and runs the dominant features. 

The stream gradient is gentler in the vicinity of site 2, 

less than 0.2 percent. Gravel and sand are the dominant 

substrates and pools are the dominant feature. Because 

of the nature of the substrates, an extensive hyporheic 

zone exists in much of the urban reach of Little 

Cottonwood Creek. The stream can be further 

characterized by extensive channelization and 

modification by structures such as diversion dams and 

head gates. Many sections of the stream are channeled 

in concrete or rip-rap to facilitate rapid downstream 

movement of snowmelt and storm flow. 

Streamflow Components 

Because of diversions of water out of Little 

Cottonwood Creek above the urban reach and imports 

to and diversions from the urban reach, natural 

streamflow conditions seldom occur in the urban reach 

between sites 1 and 2. A small hydroelectric plant (fig. 

1) withdraws water from Little Cottonwood Creek 

through a 52-in.-diameter aqueduct about 2 mi 

upstream from the mouth of Little Cottonwood 

Canyon. The water is then diverted to the Metropolitan 

Water Treatment Plant for drinking water supplies. 

During low- to moderate-flow conditions, this 

diversion results in withdrawal of all the water 

originating in the canyon before it reaches the valley 
10 Hydrology and Water Quality of Little Cottonwood Creek, Utah

and the urbanized reach. Snowmelt runoff and runoff 

from some larger storms exceed the water needs of 

upstream users, and excess water from the upper part of 

the basin reaches the valley and urbanized reach of the 

stream during these events. For several months during 

the spring and early summer, snowmelt runoff from 

Little Cottonwood Canyon makes up most of the flow 

in the valley and urbanized reach of the stream that 

includes sites 1 and 2.

During times when most of the water is diverted 

from the canyon, the sources of water for Little 

Cottonwood Creek at site 1 are localized ground-water 

inflow or sub-surface drainage and surface runoff from 

the urban area. Because of withdrawals, sections of 

Little Cottonwood Creek immediately upstream from 

site 1 and some sections downstream from site 1 are 

completely dewatered for extended periods each year. 

These sections are shown as intermittent in figure 1. 

During storms, storm drains throughout the urban study 

reach between sites 1 and 2 provide the major source of 

water to the stream.

Streamflow at site 2 may contain imported water 

from the Jordan River through the East Jordan Canal 

during about April 15 to September 15. Water is 

imported through this route to many parts of Salt Lake 

Valley. During storms or periods of low water use, 

water from the East Jordan Canal may spill and enter 

Little Cottonwood Creek at the Tower diversion (fig. 1) 

between sites 1 and 2. The water imported from the 

Jordan River has its source in a complex mix of landuse types. 

Substantial ground-water inflow contributions to 

streamflow between sites 1 and 2 were identified by 

using a synoptic approach and lithium-bromide tracer. 

The tracer-injection study was done by using methods 

and calculations described in Broshears and others 

(1993). The tracer was injected in the lower 4.5 mi of 

the reach between sites 1 and 2 on August 31, 1999. 

The tracer was injected in the upper 1.2 mi of the reach 

between sites 1 and 2 on September 2, 1999. Discharge 

in the gaining stream was determined by measuring the 

dilution of the lithium-bromide tracer as it moved 

downstream from the point of injection. Dilution of the 

tracer may be attributed to ground-water inflow to the 

stream if no surface inflows are evident. Samples were 

collected at 97 locations between sites 1 and 2. Fiftyeight sites were along Little Cottonwood Creek and 39 

were at surface-water inflows to the creek. Streamflow 

for Little Cottonwood Creek between sites 1 and 2 is 

shown in figure 4. Estimated ground-water inflow 

accounted for about 10 to 49 percent of total 

streamflow at the time of the synoptic study. The 

ground-water component of total streamflow varied 

little in the 4.4-mi reach below site 1 and then 

approximately doubled, from about 5 ft3/s to about 10 

ft3/s in the 1.3-mi reach above site 2.

Peak runoff is associated with either spring 

snowmelt from April through June, or rain occurring 

during July through October. Both types of runoff can 

result in large diurnal variations in streamflow. 

Rainstorms in late spring through fall are often of short 

duration and are associated with rapid increases and 

subsequent decreases in streamflow. 

Average annual snowfall was 516 in. during 

1948-2000 in Little Cottonwood Canyon and 94 in. in 

the urban area of the Little Cottonwood Creek drainage 

(measured at the Cottonwood Weir). Mild temperatures 

in the urban area often result in snowmelt runoff to 

Little Cottonwood Creek during or shortly after a 

winter storm; however, runoff associated with winter 

storms typically occurs throughout a longer period and 

with much lower peak flows than spring and summer 

storms. 

Daily mean streamflow for water years 1999-

2000 ranged from 0.03 to 359 ft3/s at site 1 and from 

1.3 to 357 ft3/s at site 2 (fig. 5). Annual runoff at site 1 

was 24,750 acre-ft during 1999 and 10,640 acre-ft 

during 2000. About 95 percent of the runoff resulted 

from snowmelt during April to July. Annual runoff at 

site 2 was 32,730 acre-ft during 1999 and 15,310 acreft during 2000, and about 85 percent of the runoff was 

from snowmelt during April to July (fig. 6). Total 

annual runoff at both sites during the 2000 water year 

was less than half of total annual runoff for the 1999 

water year, with the runoff peak occurring a month 

earlier in 2000 than in 1999. 

WATER QUALITY

Composition of water in a stream results from 

chemical reactions in the water, from processes that 

transfer constituents between the water and other parts 

of the biogeochemical system, and from fluxes into and 

out of the system (Stumm and Morgan, 1996). 

Temporal variations in the chemistry of Little 

Cottonwood Creek may occur as water is diverted into 

and out of the hydrologic system, chemical constituents 

enter the system from the urban environment, or 
Water Quality 11

biological and physical processes alter solute 

concentrations. Data obtained from the chemical 

analysis of water samples collected at site 1 near the 

canyon mouth and site 2 near the confluence with the 

Jordan River were used to evaluate the effects of 

urbanization on stream chemistry. 

Properties 

Physical and chemical properties including 

specific conductance, pH, water temperature, dissolved 

oxygen (DO), and alkalinity were measured in the field 

with each sample (table 1). Continuous specificconductance and water-temperature measurements 

were made at sites 1 and 2. Daily values for specific 

conductance and water temperature were calculated 

from values measured at 15-minute intervals.

Daily mean specific-conductance values at site 1 

ranged from 99 to 5,290 μS/cm (fig. 7), and 

instantaneous specific-conductance values ranged from 

72 to 9,360 μS/cm. daily mean specific-conductance 

values at site 2 ranged from 72 to 7,300 μS/cm (fig. 6), 

and instantaneous specific-conductance values ranged 

from 141 to 15,100 μS/cm. Most winter storms 

resulted in specific-conductance values exceeding 

2,000 μS/cm. Spring snowmelt and summer storms 

generally lowered specific-conductance values to 

below 250 μS/cm at site 1 and below 700 μS/cm at 

site 2. 

Well-defined relations among specificconductance values and dissolved-solids 

concentrations characterize most surface water (Hem, 

1992). Evaluation of data collected at sites 1 and 2 

indicates that specific conductance can be used to 

calculate concentrations of some other constituents, 

such as chloride and sodium, which correlate well with 

specific conductance at sites 1 and 2 (fig. 8).

The pH at site 1 ranged from 7.5 to 8.6 with a 

median value of 8.2 (fig. 9). At site 2, pH ranged from 

7.6 to 8.4 with a median value of 8.1. Larger amounts 

of aquatic vegetation and lower turbidity were observed 

at site 1 than at site 2. Because water samples at site 1 

were generally less buffered than at site 2, a higher 

level of photosynthetic activity of the aquatic 

vegetation, removing and releasing CO2 and hydrogen 

ions, may, in part, account for the larger pH range at 

site 1. The range of pH values measured at both sites 

falls within established national and Utah criteria (pH 

range of 6.5 - 9.0) for aquatic organisms.

Because DO measurements most often were 

taken at site 1 during the early afternoon and at site 2 

during mid- to late morning, diurnal changes in DO 

were not picked up by measurements at the fixed sites. 

Dissolved-oxygen concentrations ranged from 8.4 to 

14.1 mg/L at site 1 and from 7.3 to 11.4 mg/L at site 2. 

Dissolved-oxygen measurements were most often near 

or above saturation at site 1 (fig. 9), probably as a result 

of photosynthesis of aquatic vegetation. Sags in 

nighttime DO concentrations at sites 1 and 2 may have 

occurred during the study as a result of plant 

respiration. More data collection through diel (24-hour) 

oxygen studies is needed to determine whether low DO 

concentrations occur and if they are harmful to the 

environment in Little Cottonwood Creek. Dissolvedoxygen measurements were mostly near or below 

saturation at site 2, possibly as a result of the time of 

day that samples were collected or because of 

increased loads of oxygen-demanding substances and 

organic carbon. In a 1981 study of DO in the

Site 1

Site 2

0

5

10

15

20

25

Surface-water component

Ground-water component

STREAMFLOW, IN CUBIC

FEET PER SECOND

0 1 2 3 4 5 6

DISTANCE DOWNSTREAM FROM SITE 1, IN MILES

S15

S6

S12

S19

Figure 4. Streamflow between sites 1 and 2, Little Cottonwood Creek, near Salt Lake City, Utah, August 31 and September 2, 1999.
12 Hydrology and Water Quality of Little Cottonwood Creek, Utah

Figure 5. Daily mean streamflow and temporal distribution of water-quality samples at sites 1 and 2 on Little Cottonwood Creek, near Salt Lake City, 

Utah.

0

50

100

150

200

250

300

350

400

OJ M S

Streamflow

Water-quality sample

Water-quality sample - storm

1998 1999 2000

0

50

100

150

200

250

300

350

400

DAILY MEAN STREAMFLOW, IN CUBIC FEET PER SECOND

Streamflow

Water-quality sample

Water-quality sample - storm

ND FMA J J A O J M S ND FMA J J A

Site 2

Site 1
Water Quality 13

Jordan River, Little Cottonwood Creek was determined 

to be a major contributor of oxygen-demanding 

substances during non-storm periods (Stephens, 1984). 

Cumulative frequency curves of daily mean 

water temperature were developed for sites 1 and 2 by 

using daily mean values calculated from fixed interval 

(15-minute) samples (fig. 10). Because of short periods 

of missing data at both sites, these graphs represent 

cumulative distribution and not probability. The 50-

percent frequency point represents the median daily 

water temperature. The median daily water temperature 

for the study period was 7.6oC at site 1 and 10.2oC at 

site 2. Higher flows and cooler air temperatures 

resulted in a smaller annual range and slightly lower 

median value for daily mean water temperature at both 

sites in water year 1999 than in 2000. Water 

temperature ranged from 0 to 29.6oC at site 1 and from 

0.1 to 26.2oC at site 2 during this study. Winter water 

temperatures at site 1 are often low enough to result in 

ice formation. Urban and ground-water inflows 

between sites 1 and 2 generally prevent ice formation at 

site 2.

Water temperature for a typical spring and 

summer day (fig. 10) illustrate the diurnal water 

temperature change at sites 1 and 2. The range of the 

diurnal variation can be greater at site 1 than at site 2. 

This may be because of the ground-water inflow 

between sites 1 and 2, more canopy cover and less solar 

heating in the reach near site 2, and lower streamflow 

with shallower depths at site 1. The Utah Aquatic 

Criterion for maximum water temperature in Class 3A 

streams is 20oC (Utah Department of Environmental 

Quality, 1997). This criterion was exceeded on many 

days at both sites.

Major Ions 

Variations of dissolved-solids concentration and 

major inorganic chemical composition of water at sites 

1 and 2 on Little Cottonwood Creek generally are 

associated with seasonal snowmelt runoff, winter storm 

runoff, spring storms, and diversions and imports of 

irrigation water. During October to April, when 

diversions and imports are minimal or non-existent, the 

water quality of the base flow at site 1 is characteristic 

of that of ground water entering the reach above the 

site. At site 1 most of the ground-water inflow is from 

the perched shallow aquifer that is hydraulically 

connected to the stream. Base flow at site 2 is 

generally composed of surface runoff from the urban 

area and ground-water discharge from the shallow 

unconfined aquifer.

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

1999 2000

Site 2

Site 1

MONTHLY STREAMFLOW, IN ACRE-FEET

OND J FMAMJ J AS OND J FMAMJ J AS

1998

Figure 6. Monthly streamflow at sites 1 and 2 on Little Cottonwood Creek, near Salt Lake City, Utah.
14 Hydrology and Water Quality of Little Cottonwood Creek, Utah

Table 1. Minimum reporting level of parameters and constituents measured at fixed sites on Little Cottonwood Creek, near Salt Lake City, Utah—

Continued

Activity Parameter or constituent Minimum reporting

 level Unit

Field measurement

Physical properties

Discharge .01 Cubic foot per second

Specific conductance 1 Microsiemen per centimeter at 25 degrees Celsius

pH .1 Standard unit

Water temperature .1 Degree Celsius

Dissolved oxygen .1 mg/L

Alkalinity 1 mg/L

Laboratory analyses

Major ions 

Calcium, dissolved .02 mg/L

Chloride, dissolved .1 and .29 mg/L

Dissolved solids, residue on evaporation 10 mg/L

Fluoride, dissolved .1 mg/L

Magnesium, dissolved .004 and .014 mg/L

Manganese, dissolved 3.0 and 2.2 μg/L

Potassium, dissolved .1 and .24 mg/L

Silica, dissolved .05 and .09 mg/L

Sodium, dissolved .06 and .09 mg/L

Sulfate, dissolved .1 and .31 mg/L

Nutrients

Nitrogen, ammonia, dissolved .02 mg/L

Nitrogen, nitrite, dissolved .01 mg/L

Nitrogen, nitrite plus nitrate, dissolved .05 mg/L

Nitrogen, organic plus ammonia, dissolved .1 mg/L

Nitrogen, organic plus ammonia, total .1 mg/L

Phosphorus, orthophosphate, dissolved .01 mg/L

Phosphorus, dissolved .004 and .008 mg/L

Phosphorus, total .004 and .006 mg/L

Organic carbon

Dissolved .1 and .33 mg/L

Suspended .1 and .2 mg/L

Trace elements

Aluminum, dissolved 1 μg/L

Antimony, dissolved 1 μg/L

Arsenic, dissolved 1 and 2 μg/L

Barium, dissolved 1 μg/L

Beryllium, dissolved 1 μg/L

Boron, dissolved 16 μg/L

Cadmium, dissolved 1 μg/L

Chromium, dissolved 1 and .8 μg/L

Cobalt, dissolved 1 μg/L

Copper, dissolved 1 μg/L

Iron, dissolved 10 μg/L

Lead, dissolved 1 μg/L

Lithium, dissolved 1 μg/L

Molybdenum, dissolved 1 μg/L

Nickel, dissolved 1 μg/L

Selenium, dissolved 1 and 2.4 μg/L

Silver, dissolved 1 μg/L

Table 1. Minimum reporting level of parameters and constituents measured at fixed sites on Little Cottonwood Creek, near Salt Lake City, Utah

[mg/L, milligrams per liter; μg/L, micrograms per liter]
Water Quality 15

Water samples typical of low flow conditions 

were collected on November 19, 1999, at sites 1 and 2 

(fig. 11). The dissolved-solids concentration at site 1 

was 293 mg/L, with calcium and bicarbonate as the 

predominant ions. At site 2 the dissolved-solids 

concentration was 708 mg/L and the predominant ions 

were calcium, sodium, chloride, and bicarbonate. In the 

reach between sites 1 and 2, water from surface drains 

and the shallow unconfined aquifer is a higher 

percentage of the flow. Water from surface drains and 

the shallow unconfined aquifer typically contains 

higher concentrations of dissolved solids than does 

ground water from the upgradient perched aquifers.

During winter low-flow conditions, storm runoff 

often affects the water quality in the canyon and the 

valley reaches because of sodium chloride used for 

road salting. Samples collected on January 25, 1999, at 

sites 1 and 2 represent the effects of road salting after a 

winter snowstorm (fig. 11). At site 1 the dissolvedsolids concentration was 1,280 mg/L and the 

predominant ions were sodium and chloride. At site 2 

the concentration was 882 mg/L and the predominant 

ions also were sodium and chloride. The higher 

concentration occurred at site 1 because the storm 

runoff made up a greater percentage of the total flow 

there than at site 2, where there are larger contributions 

of relatively dilute ground water.

On April 20, 1999, samples were collected at 

sites 1 and 2 during a rainstorm. The dissolved-solids 

concentration was 118 mg/L at site 1 and 262 mg/L at 

site 2. Sodium and chloride were the dominant ions 

even though the concentrations were quite low relative 

to concentrations measured during winter storms. The 

high concentration of sodium and chloride ions is most 

likely residual from winter road salting.

On June 15, 1999, samples were collected during 

snowmelt runoff. The dissolved-solids concentration 

was 80 mg/L at site 1 and 171 mg/L at site 2. At site 1 

the dominant ions were calcium and bicarbonate, and at 

site 2 the dominant ions were mixed and included 

sodium, calcium, chloride, and bicarbonate ions.

During the irrigation season and periods of low 

flow, intermittent inflow from the Jordan and Salt Lake 

Canal and East Jordan Canal (fig. 1) can affect the flow 

and chemical composition of Little Cottonwood Creek 

below the inflow. The canals are operated from about 

April 15 to October 15. During storms, or when there is 

excess water that is not being used for irrigation, some 

water from the canals may also enter the stream. Not 

all of the water that enters Little Cottonwood Creek 

from the canals will reach site 2 because of diversions 

between the point of inflow and site 2. Samples 

collected at site 1 on September 2, 1999, and at site 2 

on August 31, 1999, represent a period when flow from 

the East Jordan Canal was entering the stream. The 

dissolved-solids concentration was 140 mg/L at site 1 

and 472 mg/L at site 2. Calcium and bicarbonate were 

the dominant ions at site 1 and sodium and chloride 

were dominant at site 2 during the period of inflow 

from the canal. During this period a substantial amount 

of streamflow in the East Jordan Canal was probably 

storm runoff. The concentration of dissolved solids 

normally measured at site 2 during base-flow 

conditions was reduced through dilution by inflow 

from the canal, but the canal flow contains other 

constituents that deteriorate the water quality at site 2. 

Trace elements—Continued

Strontium, dissolved 1 μg/L

Thallium, dissolved .9 μg/L

Uranium, dissolved 1 μg/L

Vanadium, dissolved 1 μg/L

Zinc, dissolved 1 μg/L

Sediment

Suspended 1 mg/L

Datalogger

Streamflow, 15-minute interval .01 Cubic foot per second

Specific conductance, 15-minute interval 1 Microsiemen per centimeter at 25 degrees Celsius

Water temperature, 15-minute interval .1 Degree Celsius

Table 1. Minimum reporting level of parameters and constituents measured at fixed sites on Little Cottonwood Creek, near Salt Lake City, Utah—

Continued

Activity Parameter or constituent Minimum reporting

 level Unit
16 Hydrology and Water Quality of Little Cottonwood Creek, Utah

 

Figure 7. Daily mean streamflow and specific conductance at sites 1 and 2 on Little Cottonwood Creek, near Salt Lake City, Utah.

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

1999 2000

Site 2

Site 1

MONTHLY STREAMFLOW, IN ACRE-FEET

OND J FMAMJ J AS OND J FMAMJ J AS

1998

0

50

100

150

200

250

300

350

400

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

Streamflow

Specific conductance

Site 2

0

1,000

2,000

3,000

4,000

5,000

6,000

1998 1999 2000

DAILY MEAN SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER CENTIMETER AT 25 DEGREES CELSIUS

0

50

100

150

200

250

300

350

400

DAILY MEAN STREAMFLOW, IN CUBIC FEET PER SECOND

Site 1

Streamflow

Specific conductance

No data

OJ M S ND FMA J J A O J M S ND FMA J J A
Water Quality 17

Figure 8. Relation of chloride and sodium concentration to specific conductance at sites 1 and 2 on Little Cottonwood Creek, near Salt Lake City, Utah.

Figure 9. Boxplots showing (A) dissolved oxygen, in percent saturation, (B) dissolved-oxygen concentration, and (C) pH at sites 1 and 2 on Little 

Cottonwood Creek, near Salt Lake City, Utah, 1999-2000 water years.

0

100

200

300

400

500

600

700

800

0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER CENTIMETER AT 25 DEGREES CELSIUS

SODIUM CONCENTRATION,

IN MILLIGRAMS PER LITER

0

200

400

600

800

1,000

1,200

1,400

CHLORIDE CONCENTRATION,

IN MILLIGRAMS PER LITER

Site 1

Site 2

Site 1

Site 2

y = 0.00004x2 + 0.1142x - 10.125

R2 R = 0.99 2 = 0.98 Winter Storm

Winter storm

Sample

collected

November

27, 2001

R2 = 0.99

R2 = 0.99

Winter storm

Winter Storm

1 2

130

DISSOLVED OXYGEN, IN

PERCENT SATURATION

CONCENTRATION OF DISSOLVED

OXYGEN , IN MILLIGRAMS PER LITER

pH, IN STANDARD UNITS

140

120

110

100

90

80

1 2

15

12

10

8

6

14

13

11

9

7

1 2

9.00

8.50

8.00

7.50

7.25

7.75

8.75

8.25

A BC

SITE

(fig. 1)

Largest value within 1.5 times the IQR above the box

75th percentile

Median (50th percentile)

25th percentile

Smallest value within 1.5 times the IQR below the box

EXPLANATION

Interquartile Range (IQR)
18 Hydrology and Water Quality of Little Cottonwood Creek, Utah

Synoptic sampling conducted on August 31 and 

September 2, 1999, identified some of the changes in 

major-ion chemistry in the reach between sites 1 and 2. 

At the time of this synoptic sampling, three substantial 

sources of water to the reach between sites 1 and 2 

were identified. Water originating in Little Cottonwood 

Canyon was the dominant influence on the water 

chemistry from site 1 downstream to the East Jordan 

Canal (fig. 1). The dominant ions at sites 1 and S6 in 

this upper reach were calcium and bicarbonate (fig. 

12). Water imported from the Jordan River and entering 

Little Cottonwood Creek from the East Jordan Canal 

through the Tower diversion was the dominant 

influence on water chemistry from the Tower diversion 

downstream to near State Street. The influence of 

ground-water inflow from near State Street 

downstream to site 2 was substantial enough to cause a 

change in water chemistry. The concentration of 

sodium, chloride, magnesium, and sulfate was higher at 

site 2 than it was in water imported from the Jordan 

River that was sampled at site S8. The dominant ions at 

sites S8 and 2 in this lower reach were mixed. Sodium 

and calcium were the dominant cations and chloride, 

bicarbonate, and sulfate were the dominant anions. 

During this synoptic study, samples were collected 

from most of the observed inflows in the study reach. 

14

16

18

20

22

24

26

28

30

0 4 8 12 16 20 24

HOUR OF DAY

August 1,1999

Site 1

Site 2

0

2

4

6

8

10

12

14

0 4 8 12 16 20 24

HOUR OF DAY

April 1, 2000

Site 1

Site 2

0

5

10

15

20

25

0 10 20 30 40 50 60 70 80 90 100

1999

2000

Site 2

0

5

10

15

20

25

1999

2000

Site 1

DAILY MEAN WATER TEMPERATURE,

IN DEGREES CELSIUS

WATER TEMPERATURE,

IN DEGREES CELSIUS

PERCENT FREQUENCY

Utah maximum water temperature criterion for cold water aquatic organisms

Utah maximum water temperature criterion for cold water aquatic organisms

Utah maximum water

temperature criterion

for cold water aquatic

organisms

Figure 10. Cumulative frequency curves of daily mean water temperature for sites 1 and 2 on Little Cottonwood Creek, near Salt 

Lake City, Utah, 1999-2000 water years, and water temperature on August 1, 1999, and April 1, 2000, at sites 1 and 2.
Water Quality 19

Water collected from many of these inflows did not 

chemically resemble the stream water and had a greater 

concentration range for most solutes (Briant A. 

Kimball, U.S. Geological Survey, written commun., 

2002). 

Nutrients

Nutrients are essential to the health and function 

of natural ecosystems. Insufficient nutrients can result 

in less than optimal growth of primary producers such 

as aquatic vegetation and limit the diversity and 

productivity of the ecosystem. Excessive nutrient 

loading, however, can result in accelerated growth of 

macrophytes, oxygen declines, imbalance of predator 

and prey species, public health concerns, and a general 

decline of the aquatic ecosystem (U.S. Environmental 

Protection Agency, 1998b). 

Nutrient transport depends on the mobility of 

each individual nutrient. Nitrate is readily dissolved 

and moves with water, whereas some forms of 

phosphorus attach to soil particles rather than dissolve 

and are transported during periods of high runoff. 

Nutrient sources in Little Cottonwood Creek are 

generally non-point. There are no permitted point 

discharges, such as waste-water treatment plants, 

which discharge into the stream. Sources of nutrients in 

Little Cottonwood Creek include fertilizer, plant decay, 

animal waste, and atmospheric deposition. 

Sodium plus potassium

Magnesium

Chloride plus fluoride

Sulfate

EXPLANATION

STREAMFLOW, IN CUBIC FEET PER SECOND

Calcium Bicarbonate plus carbonate

MILLIEQUIVALENTS PER LITER

20 0 20

1998 1999

0

50

100

150

200

250

300

350

400

Site 1

0

50

100

150

200

250

300

350

400

OCT NOV DEC JAN FEB MAR APR MAY JUNE JULY AUG SEPT

Site 2

Figure 11. Chemical composition of streamflow at sites 1 and 2 on Little Cottonwood Creek, near Salt Lake City, Utah, 1999 water year.
20 Hydrology and Water Quality of Little Cottonwood Creek, Utah

Figure 12. Composition of water samples collected from sites 1, S6, S8, and 2 on Little Cottonwood Creek, near Salt Lake City, Utah.

SULFATE PLUS CHLORIDE

80

60

40

20

80

60

40

20

CALCIUM PLUS MAGNESIUM

80

60

40

20

80

60

40

20

SODIUM PLUS POTASSIUM

80

60

40

20

80

60

40

20

MAGNESIUM

80

60

40

20

CALCIUM

PERCENT OF TOTAL MILLIEQUIVALENTS PER LITER

CHLORIDE, FLUORIDE, NITRITE PLUS NITRATE

80

60

40

20

80

60

40

20

20

40

60

80

SULFATE

CARBONATE PLUS BICARBONATE

EXPLANATION

Site 1—September 2, 1999. Dissolved-solids concentration, 140 milligrams per liter

Site S6—September 2, 1999. Dissolved-solids concentration, 212 milligrams per liter

Site S8—August 31, 1999. Dissolved-solids concentration, 444 milligrams per liter

Site 2—August 31, 1999. Dissolved-solids concentration, 472 milligrams per liter
Water Quality 21

Dissolved nitrite plus nitrate (as nitrogen) 

concentration ranged from 0.166 to 2.62 mg/L at site 1 

and from 0.241 to 1.83 mg/L at site 2 (table 2). The 

concentration of dissolved nitrite plus nitrate decreased 

at both sites with increased discharge (fig. 13) and was 

lowest during snowmelt runoff. The median 

concentration of nitrite plus nitrate at site 1 (0.593 

mg/L) and site 2 (0.508 mg/L) was near the estimated 

baseline concentration of 0.6 mg/L nitrate for 

undeveloped areas reported by Mueller and others 

(1995). This is an indication that nitrite plus nitrate 

concentrations in the urbanized reach of Little 

Cottonwood Creek are generally low. National aquaticlife criteria have not been established for nitrite plus 

nitrate or total nitrogen in streams. The Utah 

Department of Environmental Quality uses 

concentration exceedances of 4.0 mg/L as an indicant 

of nitrate pollution. All nitrite plus nitrate 

concentrations at sites 1 and 2 were less than this 

pollution indicant level.

Phosphorus is entering Little Cottonwood Creek 

between sites 1 and 2 attached to sediment particles in 

surface runoff. Total phosphorus concentration at sites 

1 and 2 generally increased with increased 

concentration of suspended sediment (fig. 14). 

Phosphorus, in the suspended phase, was generally the 

largest component of total phosphorus at sites 1 and 2 

(fig. 15). Total phosphorus concentration is greatest 

during spring and summer, particularly during storms 

or other runoff events when sediment is washed into the 

stream and higher streamflow velocities maintain more 

sediment in suspension. 

During the 1999-2000 water years, the 

concentration of total phosphorus at site 1 ranged from 

0.004 (estimated) mg/L to 0.827 mg/L (table 2). The 

U.S. Environmental Protection Agency recommends a 

limit of 0.10 mg/L total phosphorus to control 

excessive growth of algae and other nuisance plants in 

streams (U.S. Environmental Protection Agency, 

1986). The State of Utah uses 0.05 mg/L phosphate as 

a pollution indicator in all streams protected for the 

benefit of cold- and warm-water game fish and the 

aquatic organisms necessary for their food chain. At 

site 1 the concentration of total phosphorus exceeded 

0.10 mg/L in 5 of 29 samples (fig. 13). At site 2, total 

phosphorus concentration ranged from 0.029 to 2.39 

mg/L (table 2) and exceeded 0.10 mg/L in 15 of the 45 

samples.

Table 2. Summary of nutrient concentration in water samples collected from sites 1 and 2 on Little Cottonwood Creek, near Salt Lake City, Utah

[Concentration reported in milligrams per liter; <, less than; e, estimated value]

Nutrient Number of 

samples

Concentration

Minimum 25th percentile Median 75th percentile Maximum

Site 1 (Little Cottonwood Creek at Crestwood Park)

Nitrogen, ammonia, dissolved 29 <0.02 <0.02 <0.02 0.026 0.327

Nitrogen, nitrite, dissolved 29 <.01 <.01 <.01 <.01 .028

Nitrogen, nitrite plus nitrate, dissolved 29 .166 .270 .593 1.670 2.62

Nitrogen, organic, plus ammonia, dissolved 29 .07 e .1 e .140 .210 .920

Nitrogen, organic, plus ammonia, total 28 .100 .145 .160 .265 4.10

Phosphorus orthophosphate, dissolved 29 <.01 <.01 <.01 .012 .048

Phosphorus, dissolved 29 .003 e <.004 .006 .040 .070

Phosphorus, total 29 .004 e .007 .008 .018 .827

Site 2 (Little Cottonwood Creek at Jordan River)

Nitrogen, ammonia, dissolved 45 <0.02 <0.02 0.033 0.104 0.491

Nitrogen, nitrite, dissolved 45 <.01 <.01 .015 .023 .084

Nitrogen, nitrite plus nitrate, dissolved 45 .241 .392 .508 .821 1.83

Nitrogen, organic, plus ammonia, dissolved 45 .1 e .210 .310 .470 1.50

Nitrogen, organic, plus ammonia, total 44 .200 .320 .535 1.15 11.0

Phosphorus, orthophosphate, dissolved 45 <.01 .016 .023 .033 .108

Phosphorus, dissolved 45 .005 .012 .021 .043 .156

Phosphorus, total 45 .029 .050 .081 .125 2.39
22 Hydrology and Water Quality of Little Cottonwood Creek, Utah

Trace Elements 

Samples from site 1 and 2 on Little Cottonwood 

Creek were analyzed for 22 trace elements (table 1). 

The most likely sources of trace elements in the canyon 

include drainage from tunnels in previously mined ore 

bodies, unmined ore bodies, and mine tailings. The 

most likely sources in the valley include mill tailings, 

historic smelter sites, fluvial tailings, and slag lining 

the creek channel for bank stabilization. 

Quartile concentration values are those values 

that represent the 25th and 75th percentiles of a 

frequency distribution. Maximum and quartile 

concentrations of copper, zinc, and uranium were 

higher at site 1 than at site 2, indicating a source of 

these solutes in the canyon. Maximum and quartile 

concentrations of arsenic, boron, chromium, lithium, 

molybdenum, nickel, selenium, strontium, and 

vanadium were higher at site 2, indicating a source in 

the valley and urbanized reach of Little Cottonwood 

Creek (table 3). 

Flood plains downstream from mining districts 

can contain abundant deposits of fluvial tailings, 

particularly in areas adjacent to or downstream from 

older mining districts, such as the Little Cottonwood 

Mining District, which pre-date environmental 

regulations requiring containment of mine-waste 

materials. Resuspension and dissolution of fluvial 

tailings is a potential non-point source of metals in the 

Little Cottonwood Creek study reach.

Figure 13. Relation of concentration of total phosphorus and dissolved nitrite plus nitrate to streamflow at sites 1 and 2, Little Cottonwood Creek, near Salt 

Lake City, Utah.

0.1

1.0

10.0

Site 2

0.001

0.01

0.1

1.0

10.0

Site 1 Site 2

TOTAL PHOSPHORUS,

IN MILLIGRAMS PER LITER

DISSOLVED NITRITE PLUS

NITRATE, IN

MILLIGRAMS PER LITER

0

50

100

150

200

250

300

350

400

OND J FMAMJ J ASOND J FMAMJ J AS

1998 1999 2000

50

100

150

200

250

300

350

400

ONDJ FMAMJ J ASOND J FMAMJ J AS

1998 1999 2000

0

Streamflow

U.S. Environmental Protection Agency recommended maximum

concentration to control aquatic plants in streams

Sample

Sample—Nondetection

EXPLANATION

DAILY MEAN STREAMFLOW, IN CUBIC FEET PER SECOND

Site 1
Water Quality 23

A summary of trace-element concentrations for 

sites 1 and 2 during the 1999-2000 water years, 

drinking-water standards, and aquatic-life criteria are 

presented in table 3. Drinking-water standards are 

provided for comparison even though none of the water 

in the study reach is used for drinking water. Aquaticlife criteria for cadmium, copper, lead, nickel, and zinc 

are hardness dependent. As the hardness of stream 

water increases, the aquatic-life criterion concentration 

of these trace metals increases. In table 3, values of 

hardness-dependent trace metal aquatic-life criteria are 

based on a hardness of 100 mg/L calcium carbonate. 

The average hardness at the fixed sites was 143 mg/L 

as calcium carbonate at site 1 and 226 mg/L at site 2. 

Arsenic was detected in 16 of 25 samples at site 

1 in concentrations ranging from 0.7 to 7.5 μg/L (table 

3). Arsenic was detected in all 49 samples collected at 

site 2 with concentrations ranging from 4.7 to 284 

μg/L. Synoptic sampling during August 1999 in the 

urban reach between sites 1 and 2 on Little 

Cottonwood Creek indicated surface runoff and subsurface drainage in the vicinity of site S20 (fig. 2) near 

the Murray smelter tailings as the likely source of 

arsenic solutes. Arsenic concentrations were less than 

the U.S. Environmental Protection Agency (USEPA) 

aquatic-life criterion of 150 μg/L and the Utah aquaticlife criterion of 190 mg/L at site 1; at site 2 the USEPA 

criterion was exceeded in 8 of 49 samples (fig. 16) and 

the Utah criterion was exceeded in 4 of 49 samples. 

Copper concentration at sites 1 and 2 was 

elevated during snowmelt runoff relative to base flow 

during water year 1999, with a maximum concentration 

of 5.7 μg/L occurring at site 2 during May (fig. 16). 

Copper concentration measured during snowmelt 

runoff in water year 2000 was lower, probably because 

of decreased runoff from Little Cottonwood Canyon. A 

synoptic study in September 1998 (Gerner and others, 

2001) determined that copper concentration ranged 

from less than 1 to 144 μg/L at 91 sites in Little 

Cottonwood Canyon. During snowmelt, some copper is 

probably transported into the valley in the reach that 

includes sites 1 and 2. 

R2 = 0.88

0.1

1

10

100

1,000

10,000

0.001 0.01 0.1 1 10

CONCENTRATION OF TOTAL PHOSPHORUS, IN MILLIGRAMS PER LITER

CONCENTRATION OF SUSPENDED SEDIMENT,

IN MILLIGRAMS PER LITER

Figure 14. Relation of concentration of suspended sediment to total phosphorus in samples from sites 1 and 2, Little Cottonwood 

Creek, near Salt Lake City, Utah.
24 Hydrology and Water Quality of Little Cottonwood Creek, Utah

Synoptic sampling conducted on August 31 and 

September 2, 1999, showed the distribution and 

possible sources of arsenic, copper, and zinc. Samples 

were collected at a subset of 23 synoptic sites including 

fixed sites 1 and 2 and were analyzed for trace elements 

(fig. 2). The water originating from the East Jordan 

Canal and other sources downstream from the Tower 

diversion appears to contribute additional constituents 

to Little Cottonwood Creek that are not present above 

the Tower diversion. No arsenic was detected between 

sites 1 and S7 (fig. 17). Most of the water in the stream 

was being withdrawn between sites S7 and S8. Water 

from the Salt Lake and East Jordan Canal (at the Tower 

diversion, fig. 1) entered the stream immediately 

upstream of site S8. The sample from site S8 indicated 

that some arsenic was present in water from this canal. 

Arsenic concentration measured in samples from sites 

S8 downstream to site S19 ranged from 4.7 to 8.4 μg/L. 

Arsenic concentration measured at sites S20, S21, and 

2 was considerably higher and ranged from 42 μg/L to 

46 μg/L. Sites S20 and S21 were downstream from 

State Street in the vicinity of the Murray smelter site 

(fig. 1).

Zinc concentration was highest in samples from 

site 1 downstream to site S7 and ranged from 7 to 16 

μg/L. Zinc concentration was lower in samples 

collected below the Tower diversion, with 

concentration ranging from 3 to 7 μg/L. Copper 

concentration in synoptic samples ranged from 2 to 3 

μg/L at all sites.

Pesticides

Pesticides applied in the urban environment have 

a higher probability of being transported to surfacewater bodies than pesticides applied in a nonurban 

environment because of extensive impermeable 

surfaces present in urban areas (Larson and others, 

1997). Pesticides can reach the impermeable surfaces 

from direct application, spray drift, atmospheric 

deposition, or runoff from lawns and gardens. 

Application of pesticides to yards, gardens, golf 

courses, and public space in the urban areas of the 

Little Cottonwood Creek drainage basin is greatest 

during March through September.

Samples collected for pesticide analysis targeted 

those periods and events most likely to result in 

pesticide detection. Detection frequencies are likely 

biased because periods with minimal pesticide 

application were sampled at a lower intensity than 

periods when pesticides were often applied. The 

pesticide compounds analyzed for in samples collected 

from Little Cottonwood Creek are shown in table 4. 

Eighteen pesticides were detected at site 1, and 32 were 

detected at site 2. The detected pesticides include 23 

herbicides, 4 herbicide metabolites, 5 insecticides, and 

1 fungicide.

Eighteen pesticides were detected in water 

samples from sites 1 and 2 by using gas 

chromatography/mass spectrometry (GC/MS) analysis 

(table 5). The following pesticides were detected in 

water samples from sites 1 and 2 by using highperformance liquid chromatography/mass spectrometry 

(HPLC/MS) analysis:

Site 1 (Little Cottonwood Creek at Crestwood Park)

2,4 D

Clopyralid

Dicamba

0

20

40

60

80

100

SUSPENDED PHOSPHORUS,

IN PERCENT

1 2

SITE

(fig. 1)

Largest value within 1.5 times the IQR above the box

75th percentile

Median (50th percentile)

25th percentile

Smallest value within 1.5 times the IQR below the box

EXPLANATION

Interquartile Range (IQR)

Figure 15. Percentage of phosphorus in the suspended phase in 

samples from sites 1 and 2, Little Cottonwood Creek, near Salt Lake City, 

Utah.
Water Quality 25

Table 3. Summary of trace-element concentration in water samples collected from sites 1 and 2 on Little Cottonwood Creek, near Salt Lake City, Utah

[Concentration reported in micrograms per liter; v, analyte was detected in both environmental and blank samples; <, less than; —, not established; e, 

estimated value; concentration in bold italics exceeds aquatic-life criterion]

Constituent Number of 

samples

Percent 

detects

Concentration Drinking water 

standard1

Aquaticlife criterion2Utah aquatic-life 

criterion3 Maximum 75th percentile 25th percentile

Site 1

(Little Cottonwood Creek at Crestwood Park)

Aluminum 25 96 33.1 v <14.9 4.8 v 50-4200 — 587

Antimony 25 56 1.9 1.6 <1 6 30 —

Arsenic 25 64 7.5 1.6 e <1 10 150 5,6190

Barium 25 100 241 126 42.0 2,000 — —

Beryllium 25 0 <1 <1 <1 4 5.3 —

Boron 7 100 23.7 19.2 9.5 — — —

Cadmium 25 0 <1 <1 <1 5 72.2 5,71.1

Chromium 25 20 1.3 <1 <.8 100 811 —

Cobalt 25 0 <1 <1 <1 — — —

Copper 25 100 5.3 4.0 2.8 91,300 79.0 5,712

Lead 25 0 <1 <1 <1 915 72.5 5,73.2

Lithium 7 100 4.7 3.6 1.5 — — —

Molybdenum 25 100 9.0 5.9 3.1 1040 — —

Nickel 25 44 1.9 1.2 <1 10100 752 5,7160

Selenium 25 32 2.4 1.4 <1 50 5 55

Silver 25 0 <1 <1 <1 10100 — 510

Strontium 7 100 468 214 140 104,000 — —

Thallium 7 0 <.9 <.9 <.9 2 40 —

Vanadium 7 0 <1 <1 <1 — — —

Zinc 25 96 58.3 v 27.0 v 13.7 v 102,000 7120 5,7110

Uranium, natural 25 88 72.8 24.8 1.6 30 — —

Site 2

(Little Cottonwood Creek at Jordan River)

Aluminum 45 87 23.0 v 11.8 v 3.1 v 50-4200 — 587

Antimony 45 53 5.1 1.4 <1 6 30 —

Arsenic 49 100 284 87.3 11.7 10 150 5,6190

Barium 45 100 161 112 44.0 2,000 — —

Beryllium 45 0 <2 <1 <1 4 5.3 —

Boron 8 100 264 240 130 — — —

Cadmium 45 0 <2 <1 <1 5 72.2 5,71.1

Chromium 45 24 3.0 <1 <.8 100 811 —

Cobalt 45 0 <2 <1 <1 — — —

Copper 45 100 5.7 3.0 2.0 91,300 79.0 5,712

Lead 45 12 1.3 <1 <1 915 72.5 5,73.2

Lithium 8 100 109 98.5 36.6 — — —

Molybdenum 45 100 13.5 8.5 3.9 1040 — —

Nickel 45 76 3.7 2.0 1.1 10100 752 5,7160

Selenium 45 62 6.0 2.3 <1 50 5 55

Silver 45 0 <2 <1 <1 10100 — 510

Strontium 8 100 934 826 502 104,000 — —

Thallium 8 0 <.9 <.9 <.9 2 40 —

Vanadium 8 75 3.5 2.9 <1 — — —

Zinc 45 87 40.2 v 20.9 v 9.8 v 102,000 7120 5,7110

Uranium, natural 45 100 21.6 10.2 3.3 30 — —

1U.S. Environmental Protection Agency, 2002.

2Criteria Continuous Concentration (synonymous with 'Chronic'), U.S. 

Environmental Protection Agency, 1999. 3Utah Department of Environmental Quality, 1997.

4Secondary drinking-water regulation.

5Values are 4-day average (chronic) for beneficial use of cold water aquatic 

life support.

6Arsenic(III).

7Hardness-dependent value based on 100 mg/L CaCO3. 8Chromium(VI).

9Action level triggering treatment.

10Lifetime Health Advisory.
26 Hydrology and Water Quality of Little Cottonwood Creek, Utah

Diuron

MCPA

Site 2 (Little Cottonwood Creek at Jordan River)

2,4 D

2,4 DB

2,4 D Methyl ester

2-Hydroxyatrazine

Benomyl

Bromacil

Deethyldeisopropylatrazine

Deisopropylatrazine

Dicamba

Diuron

Flumetsulam

Imazaquin

MCPA

Triclopyr

Prometon is a broad-spectrum herbicide used on 

non-crop areas including rights-of-way. At the 

common reporting limit of 0.01 μg/L, prometon was 

the most frequently detected pesticide at both sites. It 

was detected in 78 percent of the samples for which it 

was analyzed from site 1 and 79 percent of the samples 

for which it was analyzed from site 2 (table 5). 

Prometon concentration was the highest measured 

among all detected pesticides, as high as 0.978 μg/L at 

site 1 and 5.61 μg/L at site 2. There is no established 

aquatic-life criterion for prometon; however, a median 

LC50 value, the concentration at which 50-percent 

mortality occurs, of 19,600 μg/L for freshwater fish 

was reported in Munn and Gilliom (2001) in a 

summary table of data from the USEPA Pesticide 

Ecotoxicity Database. An EC50 value, the 

concentration at which 50 percent of test organisms 

exhibit nonlethal responses, of 25,800 μg/L for water

0

1

2

3

4

5

6

7

8

9

10

0

50

100

150

200

250

300

Site 1

0

50

100

150

200

250

300

350

400

ARSENIC CONCENTRATION,

IN MICROGRAMS PER LITER

OND J FMAMJ J ASOND J FMAMJ J AS

1998 1999 2000

Site 2

COPPER CONCENTRATION,

IN MICROGRAMS PER LITER

Site 1 Site 2

0

50

100

150

200

250

300

350

400

DAILY MEAN STREAMFLOW, IN CUBIC FEET PER SECOND

OND J FMAMJ J ASOND J FMAMJ J AS

1998 1999 2000

EXPLANATION

Streamflow

Ambient Water Quality Criteria for protection of aquatic life (U.S.

Environmental Protection Agency, 1999)

Sample

Sample—Nondetection

AWQC = 150 micrograms per liter AWQC = 150 micrograms per liter

AWQC

Figure 16. Relation of concentration of arsenic and copper to streamflow at sites 1 and 2 on Little Cottonwood Creek, near Salt Lake City, Utah. 
Water Quality 27

fleas and 98 μg/L for green algae was reported in a 

summary table in Capel and others (1999). On the basis 

of comparisons of the concentration of prometon in 

Little Cottonwood Creek to the few LC50 and EC50

values determined for aquatic organisms, there seems 

to be little threat of acute toxicity from prometon to 

aquatic organisms in the study reach. 

The second most frequently detected pesticide at 

both sites was diazinon, which is an organophosphate 

insecticide. It is currently (2002) one of the most 

widely used insecticides in the United States, 

especially for household lawn and garden pest control. 

The concentration of diazinon exceeded the aquatic-life 

criterion of 0.08 μg/L (International Joint Commission 

United States and Canada, 1989) in 4 of 9 samples 

collected at site 1 and 8 of 42 samples collected at site 

2 (table 5). The highest concentration of diazinon 

measured was 0.343 μg/L at site 2. 

Carbaryl was detected in more than 40 percent of 

the samples at the common reporting limit of 0.01 

μg/L. The aquatic-life criterion for carbaryl had no 

exceedances in samples from site 1; in samples from 

site 2 the concentration of carbaryl exceeded the 

aquatic-life criterion of 0.2 μg/L (Canadian Council of 

Ministers of the Environment, 2001) in 4 of 42 

samples. The concentration of the insecticide 

malathion exceeded the aquatic-life criterion of 0.1 

μg/L (U.S. Environmental Protection Agency, 1999) in 

2 of 9 samples from site 1 and 1 of 42 samples from 

site 2. 

At site 2, where more frequent sampling 

occurred than at site 1, seasonal patterns in pesticide 

concentration were noted for several pesticides. 

Prometon, atrazine, diazinon, and carbaryl 

concentrations were highest during low or base-flow 

periods, which occur during late fall to early spring 

(fig. 18). Prometon and diazinon had secondary peaks 

during late summer. Application of prometon and 

diazinon begins in spring; however, samples collected 

during spring runoff had lower concentrations as a 

result of dilution from snowmelt in the upper canyon. 

Secondary peaks in concentration of these pesticides 

may be the result of additional summer application on 

lawns, orchards, and gardens in the case of diazinon, 

and rights-of-way in the case of prometon. The highest 

concentrations of prometon, diazinon, and carbaryl 

occurred during spring or summer storms. The highest 

concentration of atrazine occurred during late fall to 

early winter when most of the flow in Little 

Cottonwood Creek is from ground-water inflow and 

surface runoff from residential and commercial land 

uses. 

0

5

10

15

20

25

30

35

40

45

50

SAMPLING SITES (fig. 2)

Arsenic

Copper

Zinc

Tower diversion inflow

State Street

1 S1 S2 S3 S4 S5 S6 S7 S8 S9 S11 S12 S13 S14 S15 S19 S20 S21 2

CONCENTRATION, IN

MICROGRAMS PER LITER

S10

Figure 17. Concentration of arsenic, copper, and zinc in water collected from Little Cottonwood Creek, near Salt Lake City, Utah, August 31 and 

September 2, 1999.
28 Hydrology and Water Quality of Little Cottonwood Creek, Utah

Pesticide Type MRL

(μg/L)

Pesticides analyzed by GC/MS1

Acetochlor H 0.002

Alachlor H .002

Aniline, 2,6-diethyl HM .003

Atrazine H .001

Atrazine, Desethyl HM .002

Azinphos-methyl I .001

Benefin H .002

Butylate H .002

Carbaryl I .003

Carbofuran I .003

Chlorpyrifos I .004

Cyanazine H .004

Dacthal H .002

Deethylatrazine H .006

p,p’-DDE IM .006

Diazinon I .002

Dieldrin I .001

Disulfoton I .017

EPTC H .002

Ethalfluralin H .004

Ethoprop I .003

Ethyl Parathion I .004

Fonofos I .003

HCH, -alpha IM .002

Lindane (Gamma-hch) I .004

Linuron H .002

Malathion I .005

Methyl Parathion I .006

Metolachlor H .002

Metribuzin H .004

Molinate H .004

Napropamide H .003

Pebulate H .004

Pendimethalin H .004

Permethrin I .005

Phorate I .002

Prometon H .018

Pronamide (Propyzamide) H .003

Propachlor H .007

Propanil H .004

Propargite I .013

Simazine H .005

Tebuthiuron H .01

Terbacil H .007

Terbufos I .013

Thiobencarb H .002

Triallate H .001

Trifluralin H .002

Pesticides analyzed by HPLC/MS2

2,4-D H 0.0774

2,4-D methyl ester H .0865

2,4-DB H 3.0538

2-Hydroxyatrazine HM 3.1927

3(4-Chlorophenyl)-1-methyl urea HM .0915

3-Hydroxycarbofuran IM .0623

3-Ketocarbofuran IM 3.0723

Acifluorfen H .0622

Aldicarb I 3.0815

Aldicarb sulfone IM 3.1599

Aldicarb sulfoxide IM .0271

Bendiocarb I .0612

Pesticides analyzed by HPLC/MS2—Continued

Benomyl F .0219

Bensulfuron-methyl H .0482

Bentazon H 3.0193

Bromacil H 3.0807

Bromoxynil H 3.0572

Carbaryl H .0628

Carbofuran H .566

Chloramben methyl ester H 3.1139

Chlorimuron-ethyl H .0367

Chlorothalonil H 3.0485

Clopyralid H .0411

Cycloate H 3.0543

Dacthal monoacid HM .0722

Deethylatrazine HM 3.0868

Deethyldeisopropylatrazine HM 3.0599

Deisopropylatrazine HM 3.0737

Dicamba H .096

Dichlorprop H .05

Dinoseb H .0429

Diphenamid H .0581

Diuron H .0793

Fenuron H .0735

Flumetsulam H 3.0866

Fluometuron H .0617

Imazaquin H 3.103

Imazethapyr H 3.0879

Imidacloprid I .106

Linuron H .0695

MCPA H .0585

MCPB H 3.0625

Metalaxyl H .0571

Methiocarb I 3.0795

Methomyl I 3.0768

Methomyl oxime IM 3.0102

Metsulfuron methyl H 3.1138

Neburon H .0747

Nicosulfuron H .0653

Norflurazon H 3.0774

Oryzalin H .0711

Oxamyl I .016

Oxamyl oxime IM 3.0644

Picloram H .0712

Propham H .0717

Propiconazole F .0643

Propoxur I .0594

Siduron H .0933

Sulfometuron-methyl H .0388

Terbacil H 3.0954

Tribenuron-methyl H 3.0678

Triclopyr H .1008 1 GC/MS, U.S. Geological Survey National Water-Quality 

Laboratory schedule 2001, 2010. 2 HPLC/MS, U.S. Geological Survey National Water-Quality 

Laboratory schedule LC9060. 3 Concentration is always reported as “estimated” because of 

variability of recovery.

Pesticide Type MRL

(μg/L)

Table 4. Minimum reporting level of pesticides analyzed for in water samples collected at fixed sites on Little Cottonwood Creek, near Salt Lake City, 

Utah

[MRL, minimum reporting level; μg/L, micrograms per liter; GC/MS, gas chromatography/mass spectrometry; HPLC/MS, high-performance liquid 

chromatography/mass spectrometry; H, herbicide; HM, herbicide metabolite; I, insecticide; IM, insecticide metabolite; F, fungicide] 
Water Quality 29

Synoptic sampling conducted on August 31 and 

September 2, 1999, showed the distribution and 

possible sources of pesticides. Water samples collected 

from sites 1 and S6 had fewer pesticides detected than 

samples collected from sites S8 and 2 (fig. 19). 

Concentrations of diazinon and prometon were highest 

in samples from the two upstream sites (sites 1 and S6). 

Carbaryl also was detected in samples from the 

upstream sites but in lower concentrations than at the 

downstream sites. Malathion and atrazine also were 

detected at one or both downstream sites, S8 and 2. 

Volatile Organic Compounds

Volatile organic compounds (VOCs) are a class 

of compounds present in large quantities and used in 

many ways. They are present in fuels, exhaust, paint, 

adhesives, solvents, refrigerants, pesticides, and 

fumigants. Likely pathways for VOCs to enter a 

watershed include: (1) direct discharge into a stream 

from accidental spills and industrial or wastewater 

discharge, and (2) industrial and vehicle emissions, 

scavenged from the air by precipitation, deposited 

directly into a stream, or transported there in runoff.

Samples collected for VOC analysis at sites 1 

and 2 on Little Cottonwood Creek were analyzed for 

86 compounds (table 6). Two samples were collected 

from site 1 and 32 samples were collected from site 2. 

Benzene, chloroform, and toluene were detected in the 

two samples collected from site 1. A common reporting 

limit of 0.05 μg/L was used to compare the detection 

frequencies of VOCs that have different MRLs. 

Chloroform was the only compound detected at site 1 

above the 0.05 μg/L common reporting limit (table 7). 

At site 2, 28 compounds were detected, 23 of which 

were detected above the 0.05 μg/L common reporting 

limit. Toluene was detected in 94 percent of the 

samples and was the most frequently detected VOC. 

Acetone was the VOC detected in the highest 

concentration, at a maximum of 20 μg/L (estimated 

value). Toluene was detected at a maximum 

concentration of 3.15 μg/L in water from site 2, 

exceeding the aquatic-life criterion of 2 μg/L 

(Canadian Council of Ministers of the Environment, 

2001). It was the only VOC that exceeded established 

aquatic-life criteria in samples from sites 1 and 2.

Fuel-related BTEX compounds (benzene, 

toluene, ethyl benzene, and the xylenes) were the most 

frequently detected group of VOCs at site 2, followed 

closely by solvents. Other VOCs detected are used in 

organic synthesis, fumigation, and plastics 

manufacturing. VOC detections increased slightly with 

increased dissolved organic carbon concentration and 

decreased slightly with increasing water temperature 

(fig. 20). The coefficients of determination (R2) for the 

trends shown are small, 0.28 for graph A and 0.15 for 

graph B. The number of VOC detections in samples 

from site 2 was greatest in samples collected during 

base-flow periods in the late fall to spring and during 

storms. 

Effect of Storms 

Nutrients and pesticides may accumulate on 

impermeable surfaces in an urban area either through 

runoff from lawns and gardens or by direct application. 

Runoff during storms provides a path for these 

constituents to reach Little Cottonwood Creek and the 

Jordan River. Because of the importance of storm 

runoff to the water quality of Little Cottonwood Creek 

and the small chance of storms being sampled during 

fixed-interval sampling, several additional samples 

were collected at the fixed sites during storms (fig. 5).

At sites 1 and 2, maximum concentrations of 

many constituents including chloride, sodium, total 

phosphorus, total nitrogen, and the pesticides 

prometon, carbaryl, and diazinon were detected in 

samples collected during storms. Elevated 

concentrations during storms, often coupled with 

streamflow that is one to two orders of magnitude 

higher than base flow, resulted in substantial loads of 

these constituents in the urban reach of Little 

Cottonwood Creek. 

Spring and Summer 

Spring and summer storms are relatively short in 

duration, typically less than 4 to 6 hours. The 

hydrograph associated with a typical spring or summer 

storm in the Little Cottonwood Creek basin is 

characterized by a steep, rising limb, a peak of short 

duration, and a gradually declining, recession limb.

Elevated concentrations of nutrients and 

pesticides in samples collected during spring and 

summer storms at sites 1 and 2 indicate that 

accumulations of these constituents in the urban area 

are being transported to the stream in storm runoff. 
30 Hydrology and Water Quality of Little Cottonwood Creek, Utah

Table 5. Summary of pesticides analyzed for by gas chromatography/mass spectrometry and detected in water samples collected from sites 1 and 2 on 

Little Cottonwood Creek, near Salt Lake City, Utah 

[Concentration reported in μg/L, micrograms per liter; e, estimated value; —, not established; concentrations in bold italics exceed aquatic-life criterion]

Pesticide

Number of 

samples

Concentration Detections

Aquatic-life 

criterion Maximum Median

Total 

(including 

estimated 

values)

Frequency 

(percent)

 Above common 

reporting limit of 

0.01 μg/L

Frequency 

(percent)

Site 1 

(Little Cottonwood Creek at Crestwood Park)

Atrazine 9 0.004 0.003 4 44 0 0 11.8

Benefin 9 .010 .003 4 44 0 0 —

Carbaryl 9 .122 .050 4 44 4 44 1.2

Chlorpyrifos 9 .010 .007 4 44 0 0 2,3.041

Dacthal 9 .004 .004 4 44 0 0 —

Deethylatrazine 9 .006 e .006 e 1 11 0 0

Diazinon 9 .196 .086 7 78 6 67 3.08

EPTC 9 .104 .104 1 11 1 11 110

Malathion 9 .245 .204 3 33 3 33 3.1

Pendimethalin 9 .108 .101 4 44 3 33 —

Prometon 9 .978 .125 7 78 7 78 —

Tebuthiuron 9 .008 e .008 e 1 11 0 0 11.6

Trifluralin 9 .004 .003 3 33 0 0 1.2

Site 2

(Little Cottonwood Creek at Jordan River)

Alachlor 42 .024 .024 1 2 1 2 —

Atrazine 42 .130 .010 32 76 16 38 11.8

Benefin 42 .002 e .002 e 1 2 0 0 —

Carbaryl 42 .411 .021 28 67 21 50 1.2

Chlorpyrifos 42 .007 .005 e 3 7 0 0 2,3.041

Dacthal 42 .027 .005 19 45 3 7 —

Deethylatrazine 42 .022 .005 e 19 45 4 10 —

Diazinon 42 .343 .024 38 90 27 64 3.08

EPTC 42 .033 .003 e 6 14 1 2 110

Fonofos 42 .015 .015 1 2 1 2 —

Malathion 42 .144 .014 14 33 9 21 3.1

Metolachlor 42 .004 e .004 e 1 2 0 0 17.8

Napropamide 42 .048 .038 6 14 5 12 —

Pendimethalin 42 .174 .026 15 36 15 36 —

Prometon 42 5.61 .034 40 95 33 79 —

Simazine 42 .419 .004 e 9 21 2 5 110

Tebuthiuron 42 .69 e .016 e 15 36 11 26 11.6

Trifluralin 42 .004 e .002 e 7 17 0 0 1.2

1Canadian Government aquatic-life guidelines (Canadian Council of Ministers of the Environment, 2001).

2U.S. Environmental Protection Agency chronic aquatic-life guidelines (1999).

3Great Lakes water-quality objectives (International Joint Commission, United States and Canada, 1989).
Water Quality 31

A storm on April 14, 2000, deposited 0.50 in. of 

rain at the Cottonwood Weir, located at the mouth of 

Little Cottonwood Canyon (fig. 1). The storm, as 

defined from the streamflow hydrograph, lasted about 6 

hours, from about 0730 to 1330. Streamflow at site 2 

increased for about 3 hours from a base flow of 13 ft3/s 

to a peak flow of 187 ft3/s (fig. 21). Three samples 

were collected during the storm at site 1 and five 

samples were collected at site 2. Samples were 

collected during the storm on the streamflow rise, peak, 

and recession.

Constituent load and mean concentration 

calculations for sites 1 and 2, and in runoff between 

sites 1 and 2, during a storm on April 14, 2000, are 

shown in table 8. Land use in the drainage basin that 

contributes water to the reach of Little Cottonwood 

Creek between sites 1 and 2 is 54 percent residential 

and 46 percent other urban land uses. The effects of 

storm runoff from the urban area between sites 1 and 2 

on stream quality are shown by the increase in 

concentration and load of solutes at site 2.

Mean concentrations for selected nutrients and 

pesticides in (1) non-storm samples collected at sites 1 

and 2, (2) samples collected during the storm of April 

14, 2000, at sites 1 and 2, and (3) calculated for runoff 

between sites 1 and 2 during this storm are shown in 

figure 22. Nutrients and pesticides are present in much 

greater concentrations in samples with storm runoff 

than in non-storm samples. Runoff from urban land 

cover is a substantial source of nutrients and pesticides 

to Little Cottonwood Creek. Mean concentrations of 

total ammonia plus organic nitrogen, total nitrogen 

(total ammonia + organic nitrogen + nitrite + nitrate), 

and total phosphorus calculated for runoff between 

sites 1 and 2 for the April 14, 2000, storm were much

0

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

50

100

150

200

250

300

350

400

DIAZINON CONCENTRATION,

IN MICROGRAMS PER LITER

EXPLANATION

0

50

100

150

200

250

300

350

400

0

ATRAZINE CONCENTRATION,

IN MICROGRAMS PER LITER

D J FMAMJ J ASOND J FMAMJ J AS

1998 1999 2000

0

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

CARBARYL CONCENTRATION,

IN MICROGRAMS PER LITER

0.001

0.01

0.1

1

10

1998 1999 2000

PROMETON CONCENTRATION,

IN MICROGRAMS PER LITER

DAILY MEAN STREAMFLOW, IN CUBIC FEET PER SECOND

Streamflow

Ambient Water Quality Criteria for protection of aquatic life (International Joint Commission, United States and Canada, 1989)

Ambient Water Quality Criteria (Canadian Council of Ministers of the Environment, 2001)

Sample—fixed-interval

Sample—storm

Sample—nondetection

AWQC1 = 0.08 micrograms per liter

AWQC2 = 0.2 micrograms per liter

AWQC2 = 1.8 micrograms per liter

D J FMAMJ J ASOND J FMAMJ J AS

AWQC1

AWQC2

Figure 18. Seasonal variability of selected pesticide concentrations at site 2 on Little Cottonwood Creek, near Salt Lake City, Utah.
32 Hydrology and Water Quality of Little Cottonwood Creek, Utah

higher than those measured in non-storm samples from 

the fixed sites. Similarly, mean concentrations of 

atrazine, carbaryl, diazinon, and prometon in the runoff 

from the April 14, 2000, storm were much higher than 

what was measured in non-storm samples.

Nutrient and pesticide concentrations calculated 

for runoff to the stream between sites 1 and 2 during 

the April 14, 2000, storm were generally much higher 

than mean concentrations calculated for the storm at 

either site 1 or 2 (table 8). Atrazine, carbaryl, dacthal, 

and prometon concentrations calculated in runoff 

between sites 1 and 2 during the April 14, 2000, storm 

were more than twice the mean concentration 

calculated for the storm at site 1 and more than 30 

percent higher than mean concentrations at site 2. The 

calculated concentration of chlorpyrifos, diazinon, and 

malathion was higher at site 1 and 2 than in the runoff 

between sites 1 and 2. Concentration of these 

insecticides was highest at site 1, indicating that for this 

storm, a significant source of these insecticides was 

upstream of this site. 

Winter 

Parts of the Little Cottonwood Creek drainage 

basin have a dense network of roads that are salted 

during winter. Much of this salt runs off into the stream 

and greatly enhances the sodium and chloride 

concentration in the stream. Chloride ions are 

conservative, moving with water without being 

retarded or lost. Accordingly, almost all chloride ions 

that enter the soil and ground water in the Little 

Cottonwood Creek drainage basin have the potential to 

reach surface water. Specific-conductance values and 

chloride concentration increased in the urbanized reach 

of Little Cottonwood Creek during and following most 

winter storms. The USEPA recommends that a chloride 

concentration of 860 mg/L should not be exceeded for 

more than 1 hour every 3 years, and that a 4-day 

average chloride concentration of 230 mg/L should not 

be exceeded more than once every 3 years (U.S. 

Environmental Protection Agency, 1988). The second 

order polynomial regression equation for chloride (fig. 

8) provided an estimate of chloride concentration at 

ND

ND ND ND ND ND ND ND ND ND 0

0.02

0.04

0.06

0.08

0.10

0.12

0.14

1 S6 S8 2

CONCENTRATION, IN MICROGRAMS PER LITER

Malathion

Prometon

Diazinon

Carbaryl

Atrazine

Deethylatrazine

Not detected

SAMPLING SITES (fig. 1)

Figure 19. Concentration of selected pesticides at sites 1 and S6 on Little Cottonwood Creek, September 2, 1999, and sites S8 and 2 on Little 

Cottonwood Creek, near Salt Lake City, Utah, August 31, 1999.
Water Quality 33

Table 6. Minimum reporting level of volatile organic compounds analyzed for in water samples collected at fixed sites on Little Cottonwood Creek, near 

Salt Lake City, Utah—Continued

Parameter code name Parameter 

code

Preferred compound

name

CAS

number

MRL

(μg/L)

DIISOPROPYL ETHER 81577 Diisopropyl ether 108-20-3 0.098

1,1,1-TRICHLOROETHANE 34506 1,1,1-Trichloroethane 71-55-6 .032

1,1,2-TRICHLOROETHANE 34511 1,1,2-Trichloroethane 79-00-5 .064

1,1-DICHLOROETHANE 34496 1,1-Dichloroethane 75-34-3 .066

1,1-DICHLOROETHYLENE 34501 1,1-Dichloroethene 75-35-4 .044

1,1-DICHLOROPROPENE 77168 1,1-Dichloropropene 563-58-6 .026

1,2,3-TRICHLOROPROPANE 77443 1,2,3-Trichloropropane 96-18-4 .16

1,2-DIBROMOETHANE 77651 1,2-Dibromoethane 106-93-4 .036

1,2-DICHLOROETHANE 32103 1,2-Dichloroethane 107-06-2 .13

1,2-DICHLOROPROPANE 34541 1,2-Dichloropropane 78-87-5 .068

1,2-TRANSDICHLOROETHENE 34546 trans-1,2-Dichloroethene 156-60-5 .032

2,2-DICHLOROPROPANE 77170 2,2-Dichloropropane 594-20-7 .078

2-BUTENE, TRANS-1,4-DICHLORO- 73547 trans-1,4-Dichloro-2-butene 110-57-6 .7

2-HEXANONE 77103 2-Hexanone 591-78-6 .7

ACETONE 81552 Acetone 67-64-1 5

ACRYLONITRILE 34215 2-Propenenitrile 107-13-1 1.2

BENZENE 34030 Benzene 71-43-2 .1

BENZENE, 1,2,3-TRICHLORO- 77613 1,2,3-Trichlorobenzene 87-61-6 .27

BENZENE, 1,2,3-TRIMETHYL- 77221 1,2,3-Trimethylbenzene 526-73-8 .12

BENZENE, 1,2,4-TRICHLORO- 34551 1,2,4-Trichlorobenzene 120-82-1 .19

BENZENE, 1,2,4-TRIMETHYL- 77222 1,2,4-Trimethylbenzene 95-63-6 .056

BENZENE, 1,3,5-TRIMETHYL- 77226 1,3,5-Trimethylbenzene 108-67-8 .044

BENZENE, 1,3-DICHLORO- 34566 1,3-Dichlorobenzene 541-73-1 .054

BENZENE, 1,4-DICHLORO- 34571 1,4-Dichlorobenzene 106-46-7 .05

BENZENE, ISOPROPYL- 77223 (1-Methylethyl)benzene 98-82-8 .032

BENZENE, N-BUTYL- 77342 n-Butylbenzene 104-51-8 .19

BENZENE, N-PROPYL- 77224 n-Propylbenzene 103-65-1 .042

BENZENE, O-DICHLORO- 34536 1,2-Dichlorobenzene 95-50-1 .048

BENZENE, SEC-BUTYL- 77350 (1-Methylpropyl)benzene 135-98-8 .048

BENZENE, TERT-BUTYL- 77353 (1,1-Dimethylethyl)benzene 98-06-6 .1

BROMOBENZENE 81555 Bromobenzene 108-86-1 .036

BROMOETHENE 50002 Bromoethene 593-60-2 .1

BROMOFORM 32104 Tribromomethane 75-25-2 .1

CARBON DISULFIDE 77041 Carbon disulfide 75-15-0 .37

CARBONTETRACHLORIDE 32102 Tetrachloromethane 56-23-5 .088

CHLOROBENZENE 34301 Chlorobenzene 108-90-7 .028

CHLORODIBROMOMETHANE 32105 Dibromochloromethane 124-48-1 .18

CHLOROETHANE 34311 Chloroethane 75-00-3 .12

CHLOROFORM 32106 Trichloromethane 67-66-3 .052

CIS-1,2-DICHLOROETHENE 77093 cis-1,2-Dichloroethene 156-59-2 .038

CIS-1,3-DICHLOROPROPENE 34704 cis-1,3-Dichloropropene 10061-01-5 .09

DIBROMOCHLOROPROPANE 82625 1,2-Dibromo-3-chloropropane 96-12-8 .21

DIBROMOMETHANE 30217 Dibromomethane 74-95-3 .05

DICHLOROBROMOMETHANE 32101 Bromodichloromethane 75-27-4 .048

DICHLORODIFLUOROMETHANE 34668 Dichlorodifluoromethane 75-71-8 .14

ETHANE, 1,1,1,2-TETRACHLORO- 77562 1,1,1,2-Tetrachloroethane 630-20-6 .044

ETHANE, 1,1,2,2-TETRACHLORO- 34516 1,1,2,2-Tetrachloroethane 79-34-5 .13

ETHANE, HEXACHLORO- 34396 1,1,1,2,2,2-Hexachloroethane 67-72-1 .36

ETHER, ETHYL- 81576 Diethyl ether 60-29-7 .17

ETHER, TERT-BUTYL ETHYL- 50004 Ethyl tert-butyl ether 637-92-3 .054

ETHER, TERT-PENTYL METHYL- 50005 tert-Amyl methyl ether 994-05-8 .11

ETHYLBENZENE 34371 Ethylbenzene 100-41-4 .03

Table 6. Minimum reporting level of volatile organic compounds analyzed for in water samples collected at fixed sites on Little Cottonwood Creek, near 

Salt Lake City, Utah

[CAS number, Chemical Abstract Service number; MRL, minimum reporting level; μg/L, micrograms per liter]
34 Hydrology and Water Quality of Little Cottonwood Creek, Utah

FREON 113 77652 1,1,2-Trichloro-1,2,2-trifluoroethane 76-13-1 .032

FURAN, TETRAHYDRO- 81607 Tetrahydrofuran 109-99-9 9

HEXACHLOROBUTADIENE 39702 Hexachlorobutadiene 87-68-3 .14

ISODURENE 50000 1,2,3,5-Tetramethylbenzene 527-53-7 .2

METHACRYLATE METHYL 81597 Methyl methacrylate 80-26-6 .35

METHACRYLATE, ETHYL- 73570 Ethyl methacrylate 97-63-2 .28

METHACRYLONITRILE 81593 Methyl acrylonitrile 126-98-7 .57

METHANE, BROMOCHLORO- 77297 Bromochloromethane 74-97-5 .044

METHYL ACRYLATE 49991 Methyl acrylate 96-33-3 1.4

METHYL IODIDE 77424 Iodomethane 74-88-4 .21

METHYL TERTIARY-BUTYL ETHER (MTBE) 78032 Methyl tert-butyl ether 1634-04-4 .17

METHYLBROMIDE 34413 Bromomethane 74-83-9 .15

METHYLCHLORIDE 34418 Chloromethane 74-87-3 .25

METHYLENECHLORIDE 34423 Dichloromethane 75-09-2 .38

METHYLETHYLKETONE 81595 2-Butanone 78-93-3 1.6

METHYLISOBUTYLKETONE 78133 4-Methyl-2-pentanone 108-10-1 .37

M-XYLENE/P-XYLENE 85795 1,3 & 1,4-Dimethylbenzene 106-42-3:108-38-3 .06

NAPHTHALENE 34696 Naphthalene 91-20-3 .25

O-CHLOROTOLUENE 77275 1-Chloro-2-methylbenzene 95-49-8 .042

O-XYLENE 77135 1,2-Dimethylbenzene 95-47-6 .06

P-ISOPROPYLTOLUENE 77356 1-Isopropyl-4-methylbenzene 99-87-6 .11

PREHNITENE 49999 1,2,3,4-Tetramethylbenzene 488-23-3 .23

PROPANE, 1,3-DICHLORO- 77173 1,3-Dichloropropane 142-28-9 .12

PROPENE, 3-CHLORO- 78109 3-Chloro-1-propene 107-05-1 .2

STYRENE 77128 Ethenylbenzene 100-42-5 .042

TETRACHLOROETHYLENE 34475 Tetrachloroethene 127-18-4 .1

TOLUENE 34010 Methylbenzene 108-88-3 .05

TOLUENE, O-ETHYL- 77220 2-Ethyltoluene 611-14-3 .1

TOLUENE, P-CHLORO- 77277 1-Chloro-4-methylbenzene 106-43-4 .056

TRANS-1,3-DICHLOROPROPENE 34699 trans-1,3-Dichloropropene 10061-02-6 .13

TRICHLOROETHYLENE 39180 Trichloroethene 79-01-6 .038

TRICHLOROFLUOROMETHANE 34488 Trichlorofluoromethane 75-69-4 .09

VINYLCHLORIDE 39175 Chloroethene 75-01-4 .11

1,3, and 1,4-DIMETHYLBENZENE 85795 m/P-Xylene (Dimethyl benzene) 108-38-3 .06

Table 6. Minimum reporting level of volatile organic compounds analyzed for in water samples collected at fixed sites on Little Cottonwood Creek, near 

Salt Lake City, Utah—Continued

Parameter code name Parameter 

code

Preferred compound

name

CAS

number

MRL

(μg/L)
Water Quality 35

Table 7. Summary of volatile organic compounds detected in water samples from sites 1 and 2 on Little Cottonwood Creek, near Salt Lake City, Utah

[Concentration reported in μg/L, micrograms per liter; <, less than; e, estimated value; —, not established; concentrations in bold italics exceed aquatic-life 

criterion]

Constituent Number of 

samples

Concentration Detections

Aquaticlife 

Maximum Median criterion

Total

(including 

estimated 

values)

Above common 

reporting limit 

of 0.05 μg/L

Frequency

(percent)

Site 1

(Little Cottonwood Creek at Crestwood Park)

Benzene 2 0.009 e 0.009 1 0 0 1370

Chloroform 2 .055 e .034 2 1 50 11.8

Toluene 2 .011 e .011 1 0 0 12

Site 2

(Little Cottonwood Creek at Jordan River)

1,2,4-trimethyl-benzene 32 0.662 0.025 19 3 9 —

1,3,5-trimethyl-benzene 32 .172 .148 3 3 9 —

1,4-dichloro-benzene 32 .046 e .027 2 0 0 14

Acetone 32 20.0 e 3.52 19 19 59 —

Benzene 32 .212 .031 27 2 6 1370

1,2,3-trimethyl-benzene 32 .168 e .153 4 3 9 —

Dichlorobromomethane 32 .016 e .014 2 0 0 211,000

Bromoform 32 .156 .144 2 2 6 211,000

Carbon Disulfide 32 .084 e .076 3 2 6 32

Chloroform 32 .144 .023 29 6 19 11.8

Cis-1, 2-dichloroethene 32 .037 e .021 9 0 0 211,600

Ethylbenzene 32 .132 e .012 20 3 9 190

Isodurene 32 .135 e .125 3 3 9 —

m/p-Xylene 32 .692 .041 24 10 31 —

Methylethylketone 32 3.03 e 1.04 11 11 34 —

Methylisobutylketone 32 1.48 e .884 12 12 38 —

Methylchloride 32 .061 e .055 3 3 9 —

Methylenechloride 32 .038 e .021 12 0 0 211,000

Methyl Tertiary-butyl Ether (MTBE) 32 .075 e .043 13 3 9 —

N-butyl-benzene 32 .014 e .014 3 0 0 —

N-propyl-benzene 32 .052 e .049 3 1 3 —

P-isopropyltoluene 32 .107 e .015 12 3 9 —

Styrene 32 .103 .025 13 1 3 72

Tetrachloroethylene 32 .082 e .012 15 1 3 1111

Toluene, O-ethyl- 32 .100 e .091 3 3 9 —

Toluene 32 3.15 .115 32 30 94 12

O-xylene 32 .355 .022 19 3 9 —

Trichloroethylene 32 .071 e .036 7 2 6 121

1Canadian Government aquatic-life guidelines (Canadian Council of Ministers of the Environment, 2001).

2U.S. Environmental Protection Agency freshwater aquatic-life acute criteria/guidelines (Rowe and others, 1997).

3U.S. Environmental Protection Agency freshwater aquatic-life chronic criteria/guidelines (Rowe and others, 1997).
36 Hydrology and Water Quality of Little Cottonwood Creek, Utah

Figure 20. Relation of number of volatile organic compounds detected to (A) dissolved organic carbon, (B) water temperature, and (C) seasonal 

streamflow at site 2 on Little Cottonwood Creek, near Salt Lake City, Utah. 

Streamflow

0

2

4

6

8

10

12

14

16

18

20

0

50

100

150

200

250

300

350

400

C

J FMA M J J ASOND J F MA

1999 2000

STREAMFLOW, IN CUBIC FEET

PER SECOND

0

2

4

6

8

10

12

14

16

18

20

0 5 10 15 20 25

WATER TEMPERATURE, IN DEGREES CELSIUS

B

NUMBER OF VOLATILE ORGANIC COMPOUNDS DETECTED

0

2

4

6

8

10

12

14

16

18

20

0 2 4 6 8 10 12 14 16 18

CONCENTRATION OF DISSOLVED ORGANIC CARBON, IN MILLIGRAMS PER LITER

A
Water Quality 37

Table 8. Load and mean concentration of selected constituents at sites 1 and 2, and in runoff between sites 1 and 2, on Little Cottonwood Creek, near 

Salt Lake City, Utah, calculated for a storm on April 14, 2000

[Values in table are rounded from calculated values for load and concentration; mg/L, milligrams per liter; kg, kilograms; μg/L, micrograms per liter; g, 

grams] 

Constituent

Mean concentration1,2 Flow-weighted

 storm load

Runoff between sites 

1 and 2

Comparison of runoff 

concentration to fixed sites 

(percent)

Site 1 Site 2 Site 1 Site 2 Load3

Mean 

concentration

Site 1 Site 2

(mg/L) (mg/L) (kg) (kg) (kg) (mg/L)

Dissolved organic carbon 5.73 10.9 125 492 367 15.7 274 144

Dissolved solids, residue on 

evaporation

107 185 2,340 8,380 6,040 258 241 139

Major Ions

(mg/L) (mg/L) (kg) (kg) (kg) (mg/L)

Calcium 13.2 20.5 290 927 637 27.2 206 133

Magnesium 2.60 5.34 56.8 242 185 7.90 304 148

Potassium 1.33 2.66 29.1 121 91.6 3.91 294 147

Sodium 17.8 32.9 390 1,490 1,100 46.9 263 143

Bicarbonate 41.5 68.7 909 3,110 2,200 94.1 227 137

Chloride 30.0 51.3 657 2,330 1,670 71.2 237 139

Fluoride .170 .161 3.71 7.29 3.58 .153 90 95

Silica 3.33 3.01 72.9 136 63.6 2.71 81 90

Sulfate 8.91 16.9 195 765 570 24.3 273 144

Nutrients

(mg/L) (mg/L) (kg) (kg) (kg) (mg/L)

Nitrogen, ammonia, dissolved .174 .377 3.82 17.1 13.3 .567 326 150

Nitrogen, organic plus 

ammonia, dissolved

.479 1.09 10.5 49.4 38.9 1.66 347 152

Nitrogen, organic plus 

ammonia, total

2.95 6.06 64.6 275 210 8.96 304 148

Nitrogen, nitrite, dissolved .014 .044 .301 1.99 1.69 .072 514 164

Nitrogen, nitrate, dissolved .257 .428 5.62 19.4 13.8 .588 229 137

Nitrogen, nitrite plus nitrate, 

dissolved

.271 .472 5.92 21.4 15.5 .660 244 140

Nitrogen, total 3.18 6.47 69.5 293 224 9.55 300 148

Phosphorus, orthophosphate, 

dissolved

.046 .058 1.01 2.63 1.62 .069 150 119

Phosphorus, dissolved .066 .084 1.44 3.80 2.36 .101 153 120

Phosphorus, total .615 1.25 13.5 56.5 43.0 1.84 299 147

Trace elements

(μg/L) (μg/L) (g) (g) (g) (μg/L)

Aluminum 12.4 14.1 272 639 367 15.6 126 111

Arsenic 1.62 12.8 35.5 582 547 23.3 1,440 182

Barium 27.8 35.1 609 1,590 983 41.9 151 119

Copper 4.26 3.00 93.2 136 42.7 1.82 43 61

Iron 17.0 68.3 371 3,100 2,730 116 682 170

Manganese 8.74 51.6 191 2,340 2,150 91.7 1,050 178

Molybdenum 1.56 3.17 34.2 144 109 4.66 299 147

Uranium, natural 1.26 2.48 27.6 112 84.7 3.61 287 146

Zinc 28.1 18.9 616 856 240 10.2 36 54

Pesticides

(μg/L) (μg/L) (g) (g) (g) (μg/L)

Atrazine .001 .022 .031 .976 .944 .040 4,000 182

Carbaryl .043 .250 .951 11.3 10.4 .443 1,030 177

Chlorpyrifos .007 .003 .163 .129 0 0 0 0

Dacthal .004 .006 .089 .282 .193 .008 200 133

Diazinon .159 .140 3.48 6.36 2.88 .123 77 88

Malathion .165 .064 3.61 2.89 0 0 0 0

Prometon .471 1.18 10.3 53.3 43.0 1.84 391 156

1Stream discharge for this storm was 2.19 x 107 liters at site 1 and 4.53 x 107 liters at site 2. 2Calculated as ((load x 106)/discharge). 3Calculated as (site 2 load - site1 load).
38 Hydrology and Water Quality of Little Cottonwood Creek, Utah

site 2 based on specific-conductance values. With this 

regression equation, a chloride concentration of 860 

mg/L corresponds to a specific-conductance value of 

3,450 μS/cm. Because daily mean specific-conductance 

values exceeded 3,450 μS/cm about 9 percent of the 

time during December through March in water years 

1999 and 2000, the daily mean chloride concentration 

probably exceeded the USEPA acute criterion of 860 

mg/L about the same amount of time. On the basis of 

the regression equation (fig. 8), a chloride 

concentration of 230 mg/L corresponds to specific 

conductance of 1,410 μS/cm. Because the 4-day 

average specific-conductance value exceeded 1,410 

μS/cm more than 30 times at site 2 during 1999-2000, 

the 4-day average chloride concentration probably 

exceeded the USEPA chronic criterion of 230 mg/L 

about the same amount of time. 

Environment Canada (2001) concluded that very 

high concentrations of chloride may cause acute and 

chronic toxicity in aquatic organisms. Lower 

concentrations may affect community structure, 

diversity, and productivity. Periphyton samples were 

collected at sites 1 and 2 during summer 2000. About 5 

percent of diatom taxa identified from the sample 

collected at site 1 was very tolerant of salinity. About 

40 percent of diatom taxa identified from the sample 

collected at site 2 was very tolerant of salinity (Elise 

Giddings, U.S. Geological Survey, written commun., 

2002). The higher percentage of algae in taxa more 

tolerant of salinity at site 2 may be a result of sodium 

chloride, probably from road salts, entering the stream 

in ground-water discharge and surface runoff between 

sites 1 and 2.

SUMMARY

The Great Salt Lake Basins study unit of the 

USGS National Water-Quality Assessment program is 

1 of 51 study units designed to describe the status of 

and trends in the quality of the Nation's ground-water 

and surface-water resources. The program is intended 

to develop an understanding of the natural and human 

factors that affect those resources. A fixed-site 

assessment is a component of the surface-water study 

design used to assess the spatial and temporal 

distribution of selected constituent groups. Two fixed 

sites were established on Little Cottonwood Creek in 

Utah to help determine the influence of urbanization on 

the water quality of the stream. The objectives of this 

study were to (1) describe the hydrology and water 

quality in an urban reach of Little Cottonwood Creek 

from October 1, 1998, to September 30, 2000, (2) 

relate changes in water quality to constituent sources, 

and (3) relate constituent concentrations to established 

aquatic-life criteria. 

Figure 21. Streamflow and temporal distribution of water-quality samples at sites 1 and 2 on Little Cottonwood Creek, near Salt Lake City, Utah, 

during storm on April 14, 2000.

0

20

40

60

80

100

120

140

160

180

200

Streamflow site 1

Streamflow site 2

Sample site 1

Sample site 2

STREAMFLOW,

IN CUBIC FEET PER SECOND

0500

0600070008000900

10001100120013001400

1500

1600170018001900

HOUR OF DAY
Summary 39

The hydrology of the urbanized reach of Little 

Cottonwood Creek is highly variable and complex 

because of the canals and diversion structures utilized 

by different water users. Source water for the urban 

reach of Little Cottonwood Creek varies spatially and 

seasonally. Sources include snowmelt, storm water, 

ground water, irrigation return, and water imported 

from the Jordan River. The effect that each of these 

sources has on stream quality varies seasonally and 

with streamflow. During this study, about 85 percent of 

the runoff at the mouth of Little Cottonwood Creek was 

from snowmelt. Ground-water inflow is a major source 

of water to the urbanized reach of Little Cottonwood 

Creek. A tracer injection and synoptic sampling during 

August 31 and September 2, 1999, showed that the 

ground-water component of streamflow was variable in 

the urbanized reach and accounted for 10 to 49 percent 

of total streamflow at the time of the synoptic study. 

The Utah Division of Water Quality classifies 

water bodies in Utah according to type of water use to 

protect against controllable pollution. The urban reach 

of Little Cottonwood Creek, from the mouth of Little 

Atrazine

Carbaryl

Diazinon

Prometon

Not detected

B

0

1

2

3

4

5

6

7

8

9

10

CONCENTRATION, IN MILLIGRAMS PER LITER

Nitrogen, organic plus ammonia, total

Nitrogen, total

Phosphorus, total

A

NON-STORM SAMPLES STORM SAMPLES, APRIL14, 2000

Site 1 Runoff between

sites 1 and 2

Site 1 Site 2 Site 2

0

1

2

3

ND

ND ND

CONCENTRATION, IN MICROGRAMS PER LITER

Figure 22. Relation of mean concentration of (A) total ammonia plus organic nitrogen, total nitrogen, and total phosphorus, and (B) 

atrazine, carbaryl, diazinon, and prometon at sites 1 and 2, and in runoff between sites 1 and 2 in non-storm and storm samples, Little 

Cottonwood Creek, near Salt Lake City, Utah.
40 Hydrology and Water Quality of Little Cottonwood Creek, Utah

Cottonwood Canyon to the Jordan River, is designated 

for the beneficial uses of secondary contact recreation, 

cold water aquatic-life support, and agricultural uses.

Water temperature ranged from 0 to 29.6oC at 

site 1 and 0.1 to 26.2 oC at site 2. The maximum daily 

mean water temperature at both sites exceeded the Utah 

Class 3A aquatic criterion for maximum temperature 

(20oC) on many days. Daily mean specificconductance values at site 1 during water years 1999 

and 2000 ranged from 99 to 5,290 μS/cm. Daily mean 

specific-conductance values at site 2 during water years 

1999 and 2000 ranged from 72 to 7,300 μS/cm. The pH 

ranged from 7.5 to 8.6 at site 1 and 7.6 to 8.4 at site 2 

and falls within National and Utah established criteria 

for aquatic organisms. Dissolved oxygen 

measurements were mostly near or above saturation at 

site 1. Dissolved-oxygen measurements were mostly 

near or below saturation at site 2.

Variations in the concentration of dissolved 

solids and major inorganic chemical composition of 

water at sites 1 and 2 generally are associated with 

seasonal snowmelt runoff, winter storm runoff, spring 

storms, and diversions and imports of irrigation water. 

The dissolved-solids concentration in samples 

collected at site 1 generally was lower than that in 

samples collected at site 2. The exception was during 

winter low flow when higher concentrations of 

dissolved solids sometimes occurred at site 1 when 

storm runoff made up a higher percentage of total 

streamflow relative to site 2. Calcium and bicarbonate 

were most often the dominant ions at site 1. Sodium 

and chloride were most often the dominant ions at 

site 2. 

The median concentration of nitrite plus nitrate 

at sites 1 and 2 was near the estimated baseline 

concentration of 0.6 mg/L nitrate for undeveloped 

areas, which is an indication that nitrite plus nitrate 

concentrations in the urbanized reach of Little 

Cottonwood Creek are generally low. The USEPA 

recommends a limit of 0.10 mg/L total phosphorus to 

control excessive growth of algae and other nuisance 

plants in streams. At site 1 the total concentration of 

phosphorus ranged from 0.004 (estimated) mg/L to 

0.827 mg/L and exceeded 0.10 mg/L in 5 of 29 

samples. At site 2, total phosphorus concentration 

ranged from 0.029 to 2.39 mg/L and exceeded 0.10 

mg/L in 15 of the 45 samples.

Past mining activities and ore smelting 

operations continue to influence the water chemistry of 

the stream. Arsenic was detected in all 49 samples 

collected at site 2 with concentrations ranging from 4.7 

to 284 μg/L. The concentration of arsenic in eight 

samples from site 2 exceeded the USEPA aquatic-life 

criterion of 150 μg/L. Synoptic sampling during 

August 1999 in the urban reach between sites 1 and 2 

on Little Cottonwood Creek indicated surface runoff 

and sub-surface drainage in the vicinity of site S20 near 

the Murray smelter tailings as likely sources of arsenic 

solutes. 

Eighteen of the 107 pesticides analyzed for in 

this study were detected in at least 1 sample at site 1, 

and 32 of the 107 pesticides sampled for in this study 

were detected in at least 1 sample at site 2. The 

detected pesticides include 23 herbicides, 4 herbicide 

metabolites, 5 insecticides, and 1 fungicide. Prometon 

was the most frequently detected pesticide. Prometon 

concentration was the highest measured among all 

detected pesticides, as high as 0.978 μg/L at site 1 and 

5.61 μg/L at site 2. Diazinon was the second most 

frequently detected pesticide and exceeded the aquaticlife criterion of 0.08 μg/L in 12 of 51 samples. The 

highest concentration of diazinon was 0.343 μg/L at 

site 2. Concentrations of the insecticides malathion and 

carbaryl also exceeded the aquatic-life criteria.

Samples collected from sites 1 and 2 were 

analyzed for 86 volatile organic compounds. Three 

compounds were detected at site 1 and 28 compounds 

were detected at site 2. Fuel-related BTEX compounds 

(benzene, toluene, ethyl benzene, and the xylenes) 

were the most frequently detected group of VOCs at 

site 2, followed closely by solvents. Toluene was 

detected in 94 percent of the samples from site 2 and 

was the most frequently detected VOC. Acetone was 

the VOC detected in the highest concentration, at a 

maximum concentration of 20 μg/L. Toluene was the 

only VOC that exceeded established aquatic-life 

criteria. It was detected at a maximum concentration of 

3.15 μg/L, exceeding the aquatic-life criterion of 2 

μg/L.

Storm runoff from the urbanized area of the 

Little Cottonwood Creek drainage basin is a substantial 

source of nutrients and pesticides to Little Cottonwood 

Creek. Elevated concentrations of nutrients and 

pesticides in samples collected during spring and 

summer storms at sites 1 and 2 indicate that 

accumulations of these constituents in the urban area 

are being transported to the stream in storm runoff. 

Nutrients and pesticides can be present in a much 

higher concentration in samples with storm runoff than 

in non-storm samples. Mean concentration of total 
References Cited 41

ammonia plus organic nitrogen, total nitrogen (total 

ammonia + organic nitrogen + nitrite + nitrate), and 

total phosphorus calculated for runoff between sites 1 

and 2 for the April 14, 2000, storm were much higher 

than those measured in non-storm samples collected at 

the fixed sites. Similarly, mean concentrations of 

atrazine, carbaryl, diazinon, and prometon calculated in 

the runoff from the April 14, 2000, storm were much 

higher than those of non-storm samples.

Specific-conductance values and chloride 

concentration increased in the urbanized reach of Little 

Cottonwood Creek during and following most winter 

storms. These increases were likely the result of road 

salting. The USEPA has recommended that the 

concentration of chloride not exceed 860 mg/L for 

more than 1 hour every 3 years or a 4-day average 

concentration of 230 mg/L more than once every 3 

years. Estimates of chloride concentration determined 

from specific-conductance values indicate that chloride 

concentrations at site 2 exceeded 860 mg/L about 9 

percent of the time during December through March, 

and a 4-day average of 230 mg/L was exceeded more 

than 30 times during the study period. A higher 

percentage of algae were identified in taxa more 

tolerant of salinity in samples from site 2 than from site 

1, most likely because water with a higher salinity 

enters the stream between sites 1 and 2. 

REFERENCES CITED

Anderson, J.R., Hardy, E.E., Roach, J.T., and Witmer, R.E., 

1976, A land use and land cover classification system 

for use with remote sensor data: U.S. Geological 

Survey Professional Paper 964, 28 p.

Baskin, R.L., Thiros, S.A., Giddings, E.M., Hadley, H.K., 

Gerner, S.J., Stephens, D.W., Waddell, K.M., 2002, 

Water-quality assessment of the Great Salt Lake Basins, 

Utah, Idaho, and Wyoming—Environmental setting and 

study design: U.S. Geological Survey Water-Resources 

Investigations Report 02-4115, 47 p.

Broshears, R.E., Bencala, K.E., Kimball, B.A., and 

McKnight, D.M., 1993, Tracer-dilution experiments 

and solute-transport simulations for a mountain stream, 

Saint Kevin Gulch, Colorado: U.S. Geological Survey 

Water-Resources Investigations Report 92-4081, 18 p.

Calkins, F.C., and Butler, B.S., 1943, Geology and ore 

deposits of the Cottonwood-American Fork area, Utah: 

U.S. Geological Survey Professional Paper 201, 152 p.

Canadian Council of Ministers of the Environment, 2001, 

Canadian water quality guidelines for the protection of 

aquatic life: Summary table, accessed June 27, 2001, at 

http://www.ec.gc.ca/ceqg-rcqe

Capel, P.D., Spexet, A.H., and Larson, S.J., 1999, 

Occurrence and behavior of the herbicide prometon in 

the hydrologic system: Environmental Science and 

Technology, v. 33, no. 5, p. 674-680.

Edwards, T.K., and Glysson, G.D., 1988, Field methods for 

measurement of fluvial sediment: U.S. Geological 

Survey Open-File Report 86-531, 118 p.

Environment Canada, 2001, Priority substances list 

assessment report - road salt, accessed February 1, 

2002, at http://www.ec.gc.ca/substances/ese/eng/ 

psap/final/reports/Road_salt.pdf

Gerner, L.J., Rossi, F.J., and Kimball, B.A., 2001, Selected 

hydrologic data for Little Cottonwood Creek, Salt Lake 

County, Utah, September 1998: U.S. Geological Survey 

Open-File Report 01-38, 2 sheets. 

Gilliom, R.J., Alley, W.M., and Gurtz, M.E., 1995, Design of 

the National Water-Quality Assessment Program: 

Occurrence and distribution of water-quality 

conditions: U.S. Geological Survey Circular 1112, 33 p.

Hem, J.D., 1992, Study and interpretation of chemical 

characteristics of natural water: U.S. Geological Survey 

Water-Supply Paper 2254, 263 p.

Herbert, L.R., Allen, D.V., Wilberg, D.E., and Tibbets, J.R., 

2000, Water Resources Data, Utah, Water Year 1999: 

U.S. Geological Survey Water-Data Reports UT-99-1, 

340 p. 

Herbert, L.R., Wilberg, D.E., Tibbets, J.R., and Allen, D.V., 

2001, Water Resources Data, Utah, Water Year 2000: 

U.S. Geological Survey Water-Data Reports UT-00-1, 

380 p.

Herbert, L.R., Wilberg, D.E., and Tibbets, J.R., 2002, Water 

Resources Data, Utah, Water Year 2001: U.S. 

Geological Survey Water-Data Reports UT-01-1, 440 p.

International Joint Commission, United States and Canada, 

1989, Revised Great Lakes water quality agreement of 

1978, accessed on April 15, 2000, at http://www.ijc.org/ 

agree/quality.html#art5

Larson, S.J., Capel, P.D., and Majewski, M.S., 1997, 

Pesticides in surface waters - distribution, trends, and 

governing factors: Chelsea, Mich., Ann Arbor Press, 

373 p.

Mueller, D.K., Hamilton, P.A., Helsel, D.R., 1995, Nutrients 

in ground water and surface water of the United States - 

An analysis of data through 1992: U.S. Geological 

Survey Water-Resources Investigations Report 95-

4031, 74 p.

Mueller, D.K., Martin, J.D., and Lopes, T.J., 1997, Qualitycontrol design for surface-water sampling in the 

National Water-Quality Assessment Program: U.S. 

Geological Survey Open-File Report 97-223, 17 p.
42 Hydrology and Water Quality of Little Cottonwood Creek, Utah

Munn, M.D., and Gilliom, R.J., 2001, Pesticide toxicity 

index for freshwater aquatic organisms: U.S. 

Geological Survey Water-Resources Investigations 

Report 01-4077, 55 p.

Porterfield, G., 1972, Computation of fluvial-sediment 

discharge, U.S. Geological Survey Techniques of 

Water-Resources Investigations, book 3, chap. C3, 66 p. 

Rowe, B.L., Landrigan, S.J., Lopes, T.J., 1997, Summary of 

published aquatic toxicity information and waterquality criteria for selected volatile organic compounds: 

U.S. Geological Survey Open-File Report 97-563, 60 p.

Shelton, L.R., 1994, Field guide for collecting and 

processing stream-water samples for the National 

Water-Quality Assessment Program: U.S. Geological 

Survey Open-File Report 94-455, 42 p.

———1997, Field guide for collecting samples for analysis 

of volatile organic compounds in stream water for the 

National Water-Quality Assessment Program: U.S. 

Geological Survey Open-File Report 97-401, 14 p.

Stephens, D.W., 1984, Dissolved-oxygen regime of the 

Jordan River, Salt Lake County, Utah: U.S. Geological 

Survey Water-Resources Investigations Report 84-

4056, 56 p.

Stumm, Werner, and Morgan, J.J., 1996, Aquatic chemistry: 

Chemical equilibria and rates in natural waters: New 

York, Wiley Interscience, 1022 p.

U.S. Environmental Protection Agency, 1986, Quality 

criteria for water—1986: U.S. Environmental 

Protection Agency Report EPA 440/5-86-001.

———1988, Ambient Water Quality Criteria for Chloride: 

U.S. Environmental Protection Agency Report EPA 

440/5-88-001, 39 p.

———1998a, Record of Decision Abstract - Murray 

Smelter, accessed April 8, 2001, at http://www.epa.gov/ 

superfund/sites/rodsites/0800697

———1998b, National strategy for the development of 

regional nutrient criteria: U.S. Environmental 

Protection Agency Report EPA 822-R-98-002, 52 p.

———1999, National recommended water quality criteria - 

correction: U.S. Environmental Protection Agency 

Report EPA 822-Z-99-001, accessed May 21, 2001, at 

http://www.epa.gov/OST/standards/wqcriteria.html

———2002, 2002 edition of the drinking water standards 

and health advisories: U.S. Environmental Protection 

Agency Report EPA 822-R-02-038, accessed October 

21, 2002, at http://www.epa.gov/OST/drinking/ 

standards

Utah Department of Environmental Quality, 1997, Standards 

of quality for waters of the State, R317-2, Utah 

Administrative Code, accessed April 13, 2001, at 

http://www.rules.utah.gov/publicat/code/r317/r317-

002.htm

Wood, A.J., Lammers, D.A., Bryce, S.A., Omernik, J.M., 

Denton, R.L., Domeier, M., and Comstock, J.A., 2001, 

Ecoregions of Utah (color poster with map, descriptive 

text, summary tables, and photographs): Reston, 

Virginia, U.S. Geological Survey (map scale 

1:1,175,000).
Quality-Control Procedures and Results 43

APPENDIX

QUALITY-CONTROL PROCEDURES AND 

RESULTS 

Quality-control (QC) samples were collected 

during the study following NAWQA protocols 

(Shelton, 1994; Mueller and others, 1997). Samples 

consisted of field-blanks, equipment blanks, replicates, 

and field matrix spikes. QC samples collected at the 

Little Cottonwood Creek fixed sites are part of a larger 

group of samples collected at 10 Great Salt Lake 

Basins study unit fixed sites. Analysis of QC samples 

collected only from sites on Little Cottonwood Creek 

would not be statistically significant and, therefore, 

these samples have been combined with those collected 

at eight additional Great Salt Lake Basins study unit 

surface-water fixed sites from October 1998 to 

September 2000.

Field blanks are collected and analyzed to 

estimate bias in environmental samples. They 

demonstrate whether or not equipment has been 

adequately cleaned and whether sample collection, 

processing, and handling have introduced contaminants 

into the sample. Low concentrations of contaminants in 

field blanks could cause a positive bias in 

environmental samples with low concentrations of 

those contaminants. Contamination is considered 

significant if it exceeds 10 percent of the concentration 

measured in environmental samples. Some major ions, 

pesticides, dissolved organic carbon, and VOCs were 

detected in field blanks, but not at a concentration and 

frequency high enough to indicate a positive bias in 

environmental samples (table 9). Several nutrient 

constituents were detected in blank samples. Total 

ammonia plus organic nitrogen was the most frequently 

detected nutrient with a maximum concentration of 

0.386 mg/L and a median concentration of 0.053 mg/L. 

The range for concentration of total ammonia plus 

organic nitrogen for all samples at Little Cottonwood 

Creek fixed sites ranged from 0.10 to 11.0 mg/L and 

the median concentration was 0.35 mg/L. Zinc and 

aluminum were detected in field blanks at 

concentrations and frequencies high enough that most 

sample results have been prefaced with a 'v' remark 

code, indicating that the environmental-sample values 

have been affected by contamination. The range of zinc 

contamination in blank samples was 2.7 to 15.1 μg/L. 

The concentration of zinc in all samples at Little 

Cottonwood Creek fixed sites ranged from less than 1.0 

to 58 μg/L and the median concentration was 16 μg/L.

On the basis of QC results, it was concluded that 

measurements of concentrations in the environmental 

samples were of sufficiently high quality that the 

presence or absence of most constituents, concentration 

distributions, and comparisons to water-quality criteria 

could be determined. Sample concentrations of total 

and dissolved organic ammonia plus nitrogen and 

orthophosphate may be biased high as a result of 

contamination. Sample concentrations of aluminum 

and zinc, near the MRL, are probably biased high as a 

result of contamination.

A surrogate solution, containing a series of 

organic compounds of known concentration, was added 

to every environmental pesticide and VOC sample. The 

surrogate compounds were expected to behave in a 

manner similar to target analytes, yet not be present in 

the environment. Recovery of surrogate analytes for 

pesticide samples analyzed by using GC/MS ranged 

from 53 percent to 146 percent (table 10). Recovery of 

surrogate analytes from VOC samples ranged from 70 

percent to 118 percent.

Field matrix spike samples consisted of an 

environmental sample split into subsamples with a 

series of organic compounds that were contained in the 

analytical schedule added to one subsample. Matrix 

spike samples were used to assess extraction and 

elution recoveries from field matrices and to evaluate 

the precision of results for the target analytes in 

different environmental matrices (Shelton, 1994). 

Recovery of field spike solution analytes for pesticides 

analyzed with the GC/MS method ranged from 24 

percent to 221 percent (table 10). 

Recoveries of the surrogate and most analytes in 

field matrix spike samples analyzed for pesticides with 

the HPLC/MS method were less than 100 percent in 

more than half the samples. A laboratory detection with 

this method meant it was likely that the analyte was 

present; however, non-detections of other target 

analytes did not necessarily mean that they were not 

present.

Sample replicates were collected to provide an 

estimate of the variability of sample results. All 

replicates were split samples, in which one water 

sample was split into subsamples. These provide an 

estimate of variability associated with sample 

processing, handling, and analysis. Split samples will 

not provide an estimate of variability associated with 
44 Hydrology and Water Quality of Little Cottonwood Creek, Utah

sample collection. Relative differences for pesticides 

ranged from 0 to 80.7 percent (table 11). The median 

relative difference was 10.5 percent. The relative 

difference for nutrients ranged from 0 to 41.6 percent, 

with a median relative difference of 3.6 percent. Majorion samples had the smallest relative difference among 

split samples, ranging from 0 to 30 percent, with a 

median of 0.3 percent.
Quality-Control Procedures and Results 45

Table 9. Summary of constituents detected in field blanks collected from basic fixed sites in the Great Salt Lake Basins study unit 

[e, estimated; mg/L, milligrams per liter; μg/L, micrograms per liter; GC/MS, gas chromatography/mass spectrometry]

Constituent group Constituent Number of 

samples Detections

Concentration

Maximum Minimum

Major ions Magnesium 9 1 0.002 e mg/L 0.002 e mg/L

Sodium 9 2 .06 e mg/L .058 mg/L

Chloride 9 1 .62 mg/L .62 mg/L

Silica 9 1 .113 mg/L .113 mg/L

Nutrients Nitrogen, organic plus ammonia, dissolved 10 2 .06 mg/L .052 mg/L

Nitrogen, organic plus ammonia, total 10 3 .386 mg/L .051 mg/L

Dissolved phosphorus 10 2 .005 mg/L .004 mg/L

Orthophosphate 10 2 .021 mg/L .014 mg/L

Trace elements Zinc 3 2 15.1 μg/L 2.65 μg/L

Aluminum 3 2 9.85 μg/L 2.89 μg/L

Pesticides (GC/MS) Tebuthiuron 11 1 .007 e μg/L .007 e μg/L

Volatile organic compounds Toluene 4 1 .015 e μg/L .015 e μg/L

Table 10. Summary of surrogate and field matrix spike recovery in water samples collected from basic fixed sites in the Great Salt Lake Basins study unit 

[GC/MS, gas chromatography/mass spectrometry]

Type of spike Number of 

Samples

Spike recovery 

(percent)

Minimum 25th percentile Mean 75th percentile Maximum Standard 

deviation

Pesticide surrogate

Diazinon D10 1224 69 98 106 114 146 12

HCH, ALPHA D6 1224 53 90 96 102 135 11

Volatile organic compound surrogate

Benzene, 1,4-Bromo Fluoro- 76 70 89 95 103 118 12

Ethane, 1,2-Dichloro, D4- 76 89 101 104 107 117 5

Toluene, D8 76 87 98 100 103 111 4

Pesticide, field matrix spike - all analytes

Sample 1 (GC/MS) 1 36 107 113 122 221 28

Sample 2 (GC/MS) 1 61 93 106 115 176 25

Sample 3 (GC/MS) 1 58 93 107 117 197 27

Sample 4 (GC/MS) 1 45 87 102 113 178 28

Sample 5 (GC/MS) 1 42 92 105 120 178 28

Sample 6 (GC/MS) 1 24 91 100 110 134 20

Sample 7 (GC/MS) 1 59 98 106 115 150 19

Sample 8 (GC/MS) 1 52 92 105 109 179 24

Sample 9 (GC/MS) 1 50 95 104 111 176 22

Sample 10 (GC/MS) 1 31 79 89 99 124 18

Sample 11 (GC/MS) 1 47 89 100 113 161 21

Sample 12 (GC/MS) 1 46 81 97 110 192 25

Sample 13 (GC/MS) 1 39 94 101 115 155 21

Volatile organic compounds, field matrix spike - all analytes 

Sample 1 1 28 75 81 88 146 16 1Does not include one sample that was not spiked with surrogate solution and four samples that were probably double spiked.
46 Hydrology and Water Quality of Little Cottonwood Creek, Utah

Table 11. Summary of relative percent difference between constituents detected in split replicate sample pairs collected from fixed sites in the Great 

Salt Lake Basins study unit 

[nd, not detected; —, not sampled]

Constituent

Relative difference

 (percent)

Pair 1 Pair 2 Pair 3 Pair 4 Pair 5 Pair 6 Pair 7

Atrazine 9.7 0.4 12.7 61.3 2.3 12.1 27.2

Carbaryl nd nd nd 13.0 nd 80.7 nd

Chloropyrifos nd 41.6 nd nd nd nd nd

Dacthal nd 5.4 nd nd nd nd nd

Deethylatrazine nd 6.5 4.2 4.8 1.7 3.0 32.1

Diazinon nd 40.0 nd 2.2 nd 14.8 22.2

Malathion nd nd nd nd nd 10.5 9.5

Prometon nd 3.8 3.0 nd 13.0 18.0 22.2

Simazine nd 8.4 nd nd 10.0 45.5 nd

Nitrogen, ammonia, dissolved 20.4 nd 2.1 nd nd nd nd

Nitrogen, organic plus ammonia, 

dissolved

4.2 4.0 3.0 10.9 8.6 2.4 1.7

Nitrogen, organic plus ammonia, total 1.7 41.6 8.5 18.3 38.2 .9 3.1

Nitrogen, nitrite plus nitrate, dissolved .5 .0 2.9 1.0 1.3 3.6 4.9

Nitrogen, nitrite, dissolved 6.9 nd 5.4 nd nd 4.0 .0

Phosphorus, dissolved 1.0 .0 18.9 nd 6.5 7.1 7.4

Orthophosphorus 1.6 nd 5.0 nd nd nd nd

Phosphorus, total .6 2.5 6.5 nd 5.4 1.7 3.6

Calcium .3 .0 .6 .0 .5 .7 —

Chloride .2 .4 .5 .5 .9 .7 — 

Fluoride 10.9 .8 .3 .4 2.5 nd — 

Iron nd nd 5.9 12.9 4.1 nd — 

Magnesium .3 .0 .6 .5 .5 .9 — 

Potassium .1 .5 .5 .2 .3 4.7 — 

Silica .6 .1 .4 .2 .0 .8 — 

Sodium 1.0 .2 .4 .8 .7 1.1 — 

Sulfate .0 30.0 .1 .0 .1 .1 — 

Dissolved solids, residue on evaporation .1 .1 .0 .2 .5 .4 — 

pH .1 .1 .0 .0 .2 .3 — 

Specific conductance .1 .1 .0 .2 .0 .1 — 

Suspended organic carbon 13.0 .0 4.0 — — — — 

Dissolved organic carbon .0 .0 12.2 .6 3.3 11.8 — 

Aluminum 81.9 14.0 nd — — — — 

Antimony 2.2 2.8 .3 — — — — 

Arsenic nd .9 1.4 — — — — 

Barium 4.1 .5 1.0 — — — — 

Copper 5.3 5.6 .8 — — — — 

Lead nd nd 1.3 — — — — 

Molybdenum 1.9 .7 .7 — — — — 

Selenium 31.0 2.4 22.1 — — — — 

Uranium, natural 6.0 1.2 .8 — — — — 

Zinc 4.3 3.7 1.9 — — — — 
EXPLANATION

Steven J. Gerner and Kidd M. Waddell—Hydrology and Water Quality of an Urban Stream Reach in the Great Basin—Little Cottonwood Creek near

Salt Lake City, Utah, Water Years 1999-2000—Water-Resources Investigations Report 02–4276

National Water-Quality

Assessment Program

study unit

Great Salt Lake Basins

study unit

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