QUANTIFICATION OF METAL LOADING TO SILVER CREEK 

THROUGH THE SILVER MAPLE CLAIMS AREA, PARK CITY, 

UTAH, MAY 2002

Prepared in cooperation with the

Bureau of Land Management and the

Utah Department of Environmental Quality

By Briant A. Kimball, Kevin K. Johnson, Robert L. Runkel, and Judy I. Steiger

Salt Lake City, Utah

2004

U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report 03-4296
U.S. DEPARTMENT OF THE INTERIOR

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

For additional information write to: Copies of this report can be purchased from:

U.S. Geological Survey

Branch of Information Services

Building 810

Box 25286, Federal Center

Denver, Colorado 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.

District Chief

U.S. Geological Survey

2329 Orton Circle

Salt Lake City, Utah 84119

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

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

Introduction .......................................................................................................................................................... 1

Methods................................................................................................................................................................ 2

Tracer Injection ........................................................................................................................................... 5

Sample Collection and Analysis ................................................................................................................. 7

Mass-Loading Analysis............................................................................................................................... 7

Quantification of Metal Loading.......................................................................................................................... 9

Discharge..................................................................................................................................................... 9

Chemical Character of Synoptic Samples................................................................................................... 11

Mass Loading.............................................................................................................................................. 20

Principal Locations of Mass Loading ................................................................................................ 21

Unsampled Inflow.............................................................................................................................. 30

Attenuation......................................................................................................................................... 31

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

References Cited .................................................................................................................................................. 38

CONTENTS
iv

Figure 1. Map showing location of study reach, injection reach, and sampling sites outside the study 

reach, Silver Creek, Utah................................................................................................................... 3

Figure 2. Schematic map of injection reach, Silver Creek, Utah ...................................................................... 6

Figure 3. Graph showing variation of bromide concentration at transport sites with time, Silver Creek, 

Utah, April and May 2002 ................................................................................................................. 15

Figure 4. Graph showing variation of bromide concentration and calculated discharge with distance, 

Silver Creek, Utah.............................................................................................................................. 23

Figure 5. Graphs showing variation of (A) pH and (B) sulfate concentration with distance, Silver 

Creek, Utah ........................................................................................................................................ 25

Figure 6. Graph showing distribution of dissolved and colloidal concentration of metals in synoptic 

stream samples, Silver Creek, Utah ................................................................................................... 26

Figure 7. Graph showing variation of dissolved and colloidal aluminum concentration with distance 

for Silver Creek, Utah........................................................................................................................ 27

Figure 8. Graph showing variation of dissolved and colloidal zinc concentration with distance for Silver 

Creek, Utah ........................................................................................................................................ 28

Figure 9. Graphs showing variation of dissolved (A) sodium and (B) chloride concentration with 

distance for Silver Creek, Utah.......................................................................................................... 29

Figure 10. Photograph showing pond receiving discharge from the Silver Creek tailings discharge pipe, 

near Park City, Utah........................................................................................................................... 30

Figure 11. Graphs showing variation of (A) zinc load with distance and (B) change in load for 

individual stream segments, Silver Creek, Utah................................................................................ 33

Figure 12. Graphs showing variation of (A) sulfate load with distance and (B) change in load for 

individual stream segments, Silver Creek, Utah................................................................................ 34

Figure 13. Graphs showing variation of (A) iron load with distance and (B) change in load for 

individual stream segments, Silver Creek, Utah................................................................................ 35

Figure 14. Graphs showing load for (A) cadmium, (B) copper, (C) lead, and (D) zinc for principal 

locations, Silver Creek, Utah ............................................................................................................. 36

Figure 15. Graphs showing variation of (A) chloride load with distance and (B) change in load for 

individual stream segments, Silver Creek, Utah................................................................................ 37

FIGURES
 v

Table 1. Sample identification, source, downstream distance, site description, location, discharge, and 

tracer concentration for synoptic sampling sites, Silver Creek, Utah................................................ 4

Table 2. Physical properties of synoptic and quality-assurance samples, Silver Creek, Utah......................... 10

Table 3. Results of chemical analyses of major constituents in synoptic and quality-assurance 

samples, Silver Creek, Utah............................................................................................................... 12

Table 4. Results of chemical analyses for trace constituents in synoptic and quality-assurance samples, 

Silver Creek, Utah.............................................................................................................................. 16

Table 5. Average accuracy, precision of chemical analyses, and detection limits for synoptic samples, 

Silver Creek, Utah.............................................................................................................................. 22

Table 6. Median concentration of selected constituents, grouped by chemical similarity among synoptic 

samples, Silver Creek, Utah............................................................................................................... 24

Table 7. Calculated concentration of selected constituents in water from Silver Creek tailings discharge 

pipe, Silver Creek, Utah..................................................................................................................... 31

Table 8. Change in load for individual stream segments, Silver Creek, Utah................................................. 32

Table 9. Summary of load calculations for selected constituents, Silver Creek, Utah .................................... 32

TABLES
vi 

CONVERSION FACTORS, DATUMS, AND ABBREVIATED WATER-QUALITY 

UNITS

Water temperature in degrees Celsius (oC) can be converted to degrees Fahrenheit (oF) by using the 

following equation:

oF = 9/5(oC)+32.

Horizontal coordinate information is referenced to the North American Datum of 1927 (NAD 27).

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 mass of solute per unit volume (liter) of water. For concentrations less than 7,000 

milligrams per liter, the numerical value is about the same as for concentrations in parts per million. 

Specific conductance is reported in microsiemens per centimeter at 25 degrees Celsius (μS/cm).

Multiply By To obtain

kilogram per day (kg/day) 2.2 pound per day

milligram per second (mg/s) .1901 pound per day

liter per second (L/s) .0353 cubic foot per second (ft3/s)

meter (m) 3.281 foot (ft)

micrometer (μm) 3281000 foot (ft)

milliliter (mL) .000264 gallon
Abstract 1

QUANTIFICATION OF METAL LOADING TO SILVER CREEK 

THROUGH THE SILVER MAPLE CLAIMS AREA, PARK CITY, 

UTAH, MAY 2002

By Briant A. Kimball, Kevin K. Johnson, Robert L. Runkel, and Judy I. Steiger

ABSTRACT

The Silver Maple Claims area along Silver 

Creek, near Park City, Utah, is administered by the 

Bureau of Land Management. To quantify possible 

sources of elevated zinc concentrations in Silver 

Creek that exceed water-quality standards, the 

U.S. Geological Survey conducted a mass-loading 

study in May 2002 along a 1,400-meter reach of 

Silver Creek that included the Silver Maple 

Claims area. Additional samples were collected 

upstream and downstream from the injection reach 

to investigate other possible sources of zinc and 

other metals to the stream. Many metals were 

investigated in the study, but zinc is of particular 

concern for water-quality standards. The total 

loading of zinc along the study reach from Park 

City to Wanship, Utah, was about 49 kilograms 

per day. The Silver Maple Claims area contributed 

about 38 percent of this load. The Silver Creek 

tailings discharge pipe, which empties just inside 

the Silver Maple Claims area, contributed more 

than half the load of the Silver Maple Claims area. 

Substantial zinc loads also were added to Silver 

Creek downstream from the Silver Maple Claims 

area. Ground-water discharge upstream from the 

waste-water treatment plant contributed 20 percent 

of the total zinc load, and another 17 percent was 

contributed near the waste-water treatment plant. 

By identifying the specific areas where zinc and 

other metal loads are contributed to Silver Creek, 

it is possible to assess the needs of a remediation 

plan. For example, removing the tailings from the 

Silver Maple Claims area could contribute to 

lowering the zinc concentration in Silver Creek, 

but without also addressing the loading from the 

Silver Creek tailings discharge pipe and the 

ground-water discharge farther downstream, the 

zinc concentration could not be lowered enough to 

meet water-quality standards. Additional existing 

sources of zinc loading downstream from the 

Silver Maple Claims area could complicate the 

process of lowering zinc concentration to meet 

water-quality standards.

INTRODUCTION

Thousands of historical mining sites are located 

on Federally managed lands in the Western United 

States. Federal land management and regulatory agencies, often in cooperation with stakeholder groups, are 

faced with the challenge of choosing sites where they 

can implement remediation to lessen the effect of zinc 

and other toxic metals on streams in mountainous 

watersheds. Decisions about remediation of individual 

sites in a watershed require an understanding of the 

location and magnitude of metal loading.

Tracer-injection methods and synoptic sampling 

have been combined to quantify mass loading in many 

watersheds affected by abandoned and inactive mines 

and tailings. Mass-loading studies, together with geologic and biologic studies, can provide information that 

is needed to make science-based decisions for improvement of water quality in a watershed (Buxton and others, 1997). The Silver Maple Claims (CERCLIS # 

TUD980951396) area along Silver Creek, near Park 

City, Utah, is administered by the Bureau of Land Management (BLM). Mason (1989) investigated the 

hydrology of the Prospector Square area. Results of 
2 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

that study indicate a substantial increase in zinc (Zn) 

load in the vicinity of the Silver Maple Claims area, 

and that is attributed to the high concentrations of Zn 

that were measured in discharge from the Silver Creek 

tailings discharge pipe (CERCLIS # UTD980951404). 

A consultant report describes the details of the discharge pipe (Dames and Moore, written commun., 

1975). Giddings and others (2001) observed elevated 

metal concentrations in streambed sediments of Silver 

Creek. The geology of the area is described by Broomfield and Crittenden (1971).

The purposes of this report are to (1) determine 

the net metal loading to Silver Creek through the Silver 

Maple Claims area, (2) identify locations of metal loading through the study reach, and (3) calculate mass 

loading at additional sites outside the study reach. To 

meet these objectives, the U.S. Geological Survey 

(USGS) designed a mass-loading study along a 1,400-

m study reach that included the Silver Maple Claims 

area (fig. 1). Seven additional samples were collected 

outside of this injection reach, one upstream from the 

injection reach in Park City, one from the Pace-Homer 

ditch near the injection reach, and five downstream 

from the injection reach, the farthest one being in Wanship. Thus, two scales were used for the mass-loading 

calculations: a detailed scale in the injection reach, and 

a larger scale over the length of the Silver Creek study 

reach from Park City to Wanship. 

This work was funded by the Bureau of Land 

Management and the Utah Department of Environmental Quality through the cooperative program of the U.S. 

Geological Survey. Valuable field assistance was given 

by many individuals from the stakeholder group 

including: Heidi Hadley and Tim H. Ingwell of the 

Bureau of Land Management; John Whitehead, Alan V. 

Jones, and Ann Tillia of the Utah Department of Environmental Quality; Luke Chavez of the U.S. Environmental Protection Agency; Jay Cederberg and Steve 

Gerner of the U.S. Geological Survey; and Kerry Gee 

and Paul Lammers of United Park City Mines Company. James Mason, of the U.S. Geological Survey provided many useful suggestions on the hydrology of the 

area.

METHODS

The application of tracer-injection methods to 

mine drainage has been developed as part of the USGS 

Toxic Substances Hydrology Program (Bencala and 

McKnight, 1987; Kimball and others, 1994; Kimball 

and others, 2002). To evaluate the relative importance 

of multiple sources and the effects of instream processes, the stream and inflows must be considered in 

the hydrologic context of loads, not just in terms of 

concentrations. The load of a constituent is the product 

of its concentration and the discharge at the sampling 

site. One inflow could have a low metal concentration, 

and another could have a high concentration, but their 

discharges could differ enough so that their loads might 

be the same, in which case they would have the same 

effect on the downstream concentration.

Quantification of discharge in mountain streams 

presents unique challenges. In the Silver Maple Claims 

area, numerous beaver dams retard the flow of Silver 

Creek. The traditional area-velocity method of measuring discharge does not work in the sequence of ponds 

and braided channels. Thus, a measurement of discharge in the stream channel may miss a substantial 

percentage of the streamflow, resulting in an underestimate of metal loads.

A tracer-dilution approach is better suited for the 

problem of source determination in such a stream. In a 

complex stream like Silver Creek, the tracer must be 

injected for a sufficiently long time to come to a plateau, or steady-state condition, along the injection 

reach. Synoptic sampling of instream and inflow chemistry provides a spatially detailed “snapshot” of stream 

water quality. This sampling occurs during the tracer 

plateau. Typically one integrated sample is collected at 

a specified distance. In Silver Creek, this was possible 

at several locations at the beginning and end of the 

Silver Maple Claims area and a few other locations. 

Where the stream was spread out over a wide area 

because of beaver ponds, samples were collected near 

the left, center, and right of the stream area at the specified distances (table 1). 

 Sampling sites were selected during two reconnaissance visits to the study reach (table 1). Three samples were collected from inflows and 44 samples were 

collected from the stream. Eight quality-assurance 

samples were also collected to test replication, field 

equipment, and filtering equipment. Although it was 

possible to identify where most of the water was 
Methods 3

 

Figure 1. Location of study reach, injection reach, and sampling sites outside the study reach, Silver Creek, Utah.

Wanship 7,000Weber River

6,000

Irrigation diversion

5,500

5,000

0

375

Park City

Silver

Creek

40

o47

111o31

40

o41

111o27

0

0

1234 5 6 7

1234

Kilometers

Miles

6,500

Rockport Reservoir

Injection reach

Waste-water

treatment

plant

Richardson

Flat

Silver Creek

tailings

Irrigation

diversion

Silver Maple

Claims area

(Bureau of Land

Management property)

6,500

	






















 !



"



#

#






4 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

Table 1. Sample identification, source, downstream distance, site description, location, discharge, and tracer concentration for synoptic sampling sites, 

Silver Creek, Utah—Continued

Sample 

identification Source Distance(meters) Segment Site description Latitude Longitude Discharge(L/s)

Concentration of 

bromide

(mg/L)

1SCS-0000 S 0 S1 Silver Creek below confluence of Ontario, Empire & Deer 

Valley

40.65003 111.50002 71.9 0.15

SCS-0072 S 72 S2 Stream up from road culvert, upstream from injection 40.66685 111.48520 42.5 .15

SCS-0225 S 225 S3 Upstream from footpath culvert 40.66667 111.48334 42.5 4.57

SCS-0265 S 265 S4 T1 site - Upstream end of Prospector park pond 40.66781 111.48340 42.5 4.53

SCS-0360 S 360 S5 T2 site - Weir at end of Prospector park pond - start of Silver 

Maple Claims area (BLM property)

40.66827 111.48228 42.5 4.21

SCI-0370 LBI 370 - End of Silver Creek tailings ground-water pipe 40.66838 111.48231 212.7 .77

1SCI-0375 LBI 375 - Pace Homer Ditch at U.S. Highway 248 (across road from 

park pond)

40.66668 111.48647 395 <.05

SCI-0378 LBI 378 - Standing water to right of tailings, upstream from BLM fence 40.66668 111.46676 NC .44

SCS-0398A S 398 S6 Outflow of pond with Prospector pipe discharge - replicate 40.66843 111.48209 84.9 2.88

SCS-0398B S 398 S6 Outflow of pond with Prospector pipe discharge - replicate 40.66843 111.48209 84.9 2.98

SCS-0490R S 498 - Toward middle of marsh area 40.66668 111.46675 NC 2.90

SCS-0498C S 498 S7 Channel outside fence along right bank 40.66668 111.47190 84.9 2.83

SCS-0498L S 499 - Sample toward left bank 40.66883 111.48130 NC 3.36

SCS-0543L S 542 - Left bank upstream from beaver pond 40.66761 111.47141 NC 2.76

SCS-0543C S 543 S8 Center upstream from beaver pond 40.66668 111.46675 85.1 2.89

SCS-0543R S 544 - Right side at start of beaver pond 40.66805 111.46675 85.1 2.72

SCS-0576 S 576 S9 At breach made in mud beaver pond 40.66668 111.46675 85.1 2.92

SCS-0637L S 637 S10 Overflow from small dam/pond 40.66758 111.47134 85.1 2.90

SCS-0637R S 637 S10 Overflow from small dam/pond 40.66758 111.47134 85.1 2.98

SCS-0684 S 684 S11 Center at start of central pond 40.66941 111.47910 85.1 3.02

SCS-0711 S 710 S12 Left at return of right bank channel outside fence 40.66935 111.47878 85.1 2.96

SCS-0778A S 778 S13 T3 site - Downstream end of small pond below large pond 40.66985 111.47832 NC 2.73

SCS-0778B S 778 S13 T3 site - Downstream end of small pond below large pond 40.66985 111.47832 NC 2.63

SCS-0832L S 831 - Left side near fallen tree along left bank - most of flow on left 40.67002 111.47771 90.2 2.66

SCS-0832C S 832 S14 Center near fallen tree along left bank 40.67002 111.47771 90.2 2.73

SCS-0832R S 833 - Right side near fallen tree along left bank 40.67002 111.47771 90.2 2.70

SCS-0877 S 877 S15 Upstream end of pond with large beaver lodge 40.66997 111.47725 90.2 2.75

SCS-0940 S 940 S16 Channel flow downstream from beaver pond at cut bank 40.66793 111.47022 90.2 2.75

SCS-0990L S 989 - Left side with spread out channel near post 40.66792 111.47052 NC 2.67

SCS-0990C S 990 - Center channel between two other samples 40.66787 111.47051 NC 2.68

SCI-0991 LBI 991 - Left bank ditch as possible inflow water 40.66795 111.50123 NC .46

SCS-0992 S 992 S17 Channel gathered - good for discharge measurement 40.67017 111.47632 90.2 2.83

SCS-1017 S 1,017 S18 Fence at downstream; end of Silver Maple Claims area 

(BLM property)

40.67030 111.47572 90.2 2.75

SCS-1079L S 1,079 - Left side at small dam down from Silver Maple 40.67052 111.47511 NC 2.70

SCS-1079C S 1,080 - Center at small dam down from Silver Maple 40.67052 111.47511 NC 2.81

SCS-1079R S 1,081 S19 Right side at small dam down from Silver Maple 40.67052 111.47511 90.2 2.82

SCI-1140 LBI 1,140 - Drainage from breach of Pace Homer Ditch 40.67093 111.47482 NC .06

SCS-1162 S 1,162 - At a dam up from bridge 40.67083 111.47419 NC 2.62

SCS-1165 S 1,165 - Left bank sample in channel with irrigation inflow 40.67098 111.47419 NC 2.09

SCS-1212 S 1,212 S20 Upstream end of pond at final bridge 40.67101 111.47368 90.2 2.78

SCS-1344A S 1,344 S21 T4 site - Down from pond at bridge - replicate 40.66818 111.46868 90.2 2.80

SCS-1344B S 1,344 S21 T4 site - Down from pond at bridge - replicate 40.66818 111.46868 90.2 2.64

SCS-1380 S 1,380 S22 At small, old wood walking bridge 40.67095 111.47168 90.2 2.61

SCS-1420 S 1,420 S23 End of reach down from pipes across stream 40.67129 111.47154 90.2 2.61

1SCS-5000A S 5,000 S24 Silver Creek 100 meters above Richardson Flat 40.68108 111.45805 165 <.05

Table 1. Sample identification, source, downstream distance, site description, location, discharge, and tracer concentration for synoptic sampling sites, 

Silver Creek, Utah

[Sample identification, unique sample identifier; Source: S, stream; LBI, left bank inflow; Distance along the study reach, in meters; BLM, Bureau of Land 

Management; Latitude and Longitude, in decimal degrees; L/s, liters per second; mg/L, milligrams per liter; NC, discharge not calculated, sample was not in 

the main channel; <, less than]
Methods 5

moving along the study reach in those parts of Silver 

Creek affected by beaver dams, in some areas all the 

water entered large beaver ponds. Each stream sample 

that was considered in the main channel (table 1) 

defines the downstream end of a stream segment. Each 

stream segment was given a sequential number from 

upstream to downstream, and each represents the mass 

loading contributed by a given part of the watershed. 

The length of the segment is the difference between the 

upstream and downstream distances. A schematic view 

of the sampling sites for the injection reach is shown in 

figure 2.

To quantify the arrival, plateau, and departure of 

the tracer, continuous samples were collected at four 

sites along the study reach. During the 72 hours prior to 

the synoptic sampling, samples at these transport sites 

define the hydrologic properties of the stream. The 

arrival and departure of the tracer provide information 

about the residence time between sites, stream crosssectional area, exchange rate of the stream with the 

hyporheic zone, and the stream discharge as the tracer 

reaches a plateau concentration. Transport samples 

were collected by individuals at the transport sites 

during the arrival and departure periods and by autosampler throughout the plateau of the injection period. 

Transport sites were located at the upstream end of the 

pond in Prospector Park (T1), at the weir at the downstream end of the pond in Prospector Park (T2), downstream from the largest beaver pond where there is a 

majority of flow for a short reach (T3), and at the end 

of the study reach (T4). Only one 125-mL bottle of filtered, untreated (FU) water is collected for the transport sampling.

Several publications provide details about tracer 

injections, including Bencala and others (1990), Broshears and others (1993), Kimball and others (1994, 

1999, 2001, and 2002), and Zellweger and others 

(1988).

Tracer Injection

The tracer injection began with a careful evaluation of all visible inflows to the injection reach, which 

was accomplished by walking the entire reach from 

Prospector Park to the end near 1,421 m (fig. 2). Sampling sites within the injection reach are referenced in 

this report by the measured downstream distance along 

the injection reach. The distance from one stream site 

to the next site downstream represents a stream segment. The injection began at 10:55 hours on April 29, 

2002, and continued until 16:55 hours on May 2, 2002. 

Sodium bromide was selected for the injection solution. Bromide (Br) was considered a good tracer 

because of the high pH of the stream and the lack of 

geologic sources of Br in the watershed. The injection 

solution had a Br concentration of 255,500 mg/L, and 

was injected at a rate of 0.00107 L/s. 

Precision metering pumps were used to inject the 

tracer. A Campbell CR-10 data logger controlled the 

pumps by counting pump revolutions and adjusting the 

voltage to maintain a constant number of revolutions 

for each 2-minute period. This careful control assures 

that any observations of tracer concentration downstream result from hydrologic change and not from 

pump variation. In the analysis of this experiment, Br is 

assumed to be a conservative tracer. No adverse effects 

were observed from the injection of the tracer solution.

A continuously injected chemical tracer provides 

a way to measure discharge that includes the hyporheic 

flow of the stream because it follows the water as it 

moves in and out of the streambed. During base-flow 

conditions, tracer dilution allows the detection of 

increases in streamflow of only a few percent. Once the 

tracer reaches a steady concentration at each point 

along the stream, called the plateau condition, 

1SCS-5000B S 5,500 S25 Silver Creek 50 meters below U.S. Highway 248 road 

crossing

40.68562 111.45286 235 <.05

1SCS-6000A S 6,000 S26 Silver Creek above Silver Creek waste-water treatment plant 40.71946 111.47138 28.9 <.05

1SCS-6000B S 6,500 S27 Silver Creek below Silver Creek waste-water treatment plant 40.73404 111.47636 117 <.05

1SCS-7000 S 7,000 S28 Silver Creek at town of Wanship 40.80351 111.40272 532 <.05 

1Sample collected on 5/1/2002, outside of mass-loading study reach.

2Measured by flow meter at the end of the pipe.

3Discharge of ditch does not contribute to the discharge of Silver Creek in the study reach.

Table 1. Sample identification, source, downstream distance, site description, location, discharge, and tracer concentration for synoptic sampling sites, 

Silver Creek, Utah—Continued

Sample 

identification Source Distance

(meters) Segment Site description Latitude Longitude Discharge

(L/s)

Concentration of 

bromide

(mg/L)
6 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

discharge can be calculated at any point. During the 

tracer plateau, numerous samples along the stream 

provide a synoptic sampling. Each stream sample has a 

measured discharge because of the tracer concentration 

in the synoptic sample.

Concentrations of bromide in stream environments are typically low, with background concentrations at or near the lower detection limits. Spatial 

variability in background concentrations is low, such 

that background concentrations are nominally uniform. 

Assuming uniform background concentrations, stream 

discharge at any location downstream from the injection is given by:

(1)

where

QD is stream discharge, in L/s,

QINJ is the injection rate, in L/s,

CINJ is the injectate concentration, in mg/L,

CD is the tracer concentration at plateau, in mg/L, 

and

CB is the naturally occurring background 

concentration, in mg/L.

The amount of tracer dilution between two consecutive stream sites indicates the total inflow from 

surface and ground water for that segment of the injection reach. Tracer dilution accounts for visible inflows, 

QD

QINJCINJ ( )

CD CB – = ---------------------------

 

Figure 2. Schematic map of injection reach, Silver Creek, Utah.

459000 459200 459400 459600 459800 460000 460200

4501700

4501800

4501900

4502000

4502100

4502200

72

225

265

360

370

378

398

498

498

499

542

543

544

576 637

684710

778

831-3

877

940

989

990 991-2

1,017

1,079-81

1,140

1,162

1,165 1,212 1,344

1,380

1,420

NORTHING, IN METERS

EASTING, IN METERS

Injection site

T1 Site

Upper end of pond



	


	



		

			

	

		




 	


		

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%
	



499
Methods 7

such as tributaries and springs, as well as dispersed, 

subsurface inflow. To divide the total inflow within a 

stream segment into surface- and ground-water components would require a secondary discharge measurement of the inflow.

Sample Collection and Analysis

Synoptic sampling is used to quantify discharge 

and detailed longitudinal profiles of chemistry along a 

stream reach. For the injection reach, sampling proceeded from downstream (1,421 m) to upstream (72 m) 

to avoid disturbing the bed materials. Samples outside 

the injection reach were collected the day prior to the 

synoptic sampling. Because the flow was spread out 

over most of the bottom area of Silver Creek, many of 

the samples were grab samples across a transect of the 

area of flow. Where possible, samples were collected at 

well-defined stream cross sections by using integrating 

techniques (Ward and Harr, 1990). A hand-held, depthintegrating, Teflon sampler was used for both the single 

vertical grab samples and the width-integrated samples. 

Temperature was measured at the time of sample collection and recorded along with field notes about the 

sampling conditions, character of the streambed, and 

any important observations. Samples were transported 

to a centrally located field laboratory where filtration 

could occur with standardized procedures to control 

contamination. The processing included a (1) raw, 

untreated (RU) sample for pH and conductance; (2) a 

raw, acidified sample (RA) for total-recoverable metals; (3) a 0.45-μm filtered, acidified (FA) sample for filtered metal concentrations; and (4) a 0.45-μm filtered, 

untreated (FU) sample for tracer and other anions.

Colloidal metal concentrations are important for 

understanding the transport and transformation of 

metals (Kimball and others, 1995). The colloidal concentration was calculated as the difference between the 

total-recoverable and the filtered concentrations (Kimball and others, 1995). Metal concentrations were 

determined by inductively coupled argon plasma - mass 

spectrometry for calcium (Ca), magnesium (Mg), 

sodium (Na), potassium (K), aluminum (Al), cadmium 

(Cd), chromium (Cr), cobalt (Co), copper (Cu), iron 

(Fe), lead (Pb), lithium (Li), manganese (Mn), molybdenum (Mo), nickel (Ni), strontium (Sr), silica (SiO2), 

vanadium (V), and Zn. Anions were determined by ion 

chromatography and included sulfate (SO4), chloride 

(Cl), fluoride (F), the Br tracer, and nitrate (NO3). 

Alkalinity, as calcium carbonate (CaCO3), was determined by titration.

Mass-Loading Analysis

Because of the beaver dams throughout the injection reach, quantifying stream discharge was difficult. 

To quantify the change in load for the Silver Maple 

Claims area required accurate discharge and chemical 

measurements at the beginning (360 m) and end (1,017 

m) of the area. Stream discharge measurements were 

possible because both locations had reasonably well 

channelized cross sections and were easily sampled. To 

quantify more detailed changes in load was not as 

straightforward. Obtaining changes in discharge from 

the tracer was possible only for those segments where 

there was a clear change in tracer concentration. There 

were many individual segments for which discharge 

was unchanged. To quantify loads for those sites outside the injection reach required accurate discharge 

measurements by flow meter. Flow-meter measurements do not include water transported in the hyporheic 

zone, which is quantified by a tracer-injection study 

(Kimball and others, 2002). 

Profiles of mass load along the study reach use 

three different views of load. Sampled instream load at 

individual sampling sites is calculated as:

(2)

where

Ma is the constituent load at location a, in kg/day,

Ca is the concentration of the selected constituent 

at location a, in mg/L, 

Qa is the discharge at location a, in L/s, and

0.0864 is the conversion factor from mg/s to kg/day.

Sampled instream load is calculated from the 

total-recoverable concentration of the constituent, but 

this value for load can be divided between the dissolved and the colloidal load if both filtered and totalrecoverable samples are collected. The longitudinal 

profile of sampled instream load is the basic data from 

the mass-loading study. 

The change in load between a pair of stream 

sites, or for a stream segment, accounts for the gain or 

loss of constituent load for that segment. For the 

change in load for the segment starting at location a

and ending at location b, we calculate:

Ma CaQa = ( ) 0.0864
8 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

(3)

where 

∆Ms is the change in sampled instream load 

from location a to b, in kg/day, 

Cb is the concentration of the selected 

constituent at location b, in mg/L, 

 Qb is the discharge at location b, in L/s, 

 Ca and Qa are defined above, and

0.0864 is the conversion factor from mg/s to 

kg/day.

Gains in constituent load (∆Ms is greater than 

zero) imply that there is a source that contributes to the 

stream between the two stream sites. Instream load also 

can decrease within a stream segment (∆Ms is less than 

zero), meaning that there was a net loss of the constituent from physical, chemical, or biological processes. 

Summing all the increases in load between sampling 

sites along the study reach (positive values of ∆Ms) 

leads to the cumulative instream load. At the end of the 

study reach, the cumulative instream load is the best 

estimate of the total load added to the stream but is 

likely a minimum estimate because it only measures 

the net loading between sites and does not account for 

loss resulting from reaction.

For those segments that include a sampled 

inflow, it is possible to calculate a second value for load 

that is based upon the change in discharge between 

stream sites. This change, multiplied by constituent 

concentration in an inflow sample, produces an estimate of the inflow load for a stream segment. If stream 

sites a and b surround an inflow sample, location i:

(4)

where

∆Mi is the change in sampled inflow load from 

location a to b, in kg/day,

Ci is the concentration of the selected 

constituent at inflow location i, in mg/L,

Qa and Qb are defined above, and 

0.0864 is the conversion factor from mg/s to 

kg/day.

Summing the inflow loads along the study reach 

produces a longitudinal profile of the cumulative 

inflow load. This sum can be compared to the cumulative instream load to indicate how well the sampled 

inflows account for the load measured in the stream. 

The cumulative instream and cumulative inflow profiles would be equal if the sampled inflows were representative of the constituent concentration for all the 

water entering the stream, but that is rarely the case. 

Ground-water inflow in streams affected by mine 

drainage commonly has higher concentrations of 

metals than the surface-water inflows in the same 

stream segment. This causes the profile of cumulative 

instream load to be greater than the profile of cumulative inflow load, and can indicate important areas of 

unsampled inflow, which is defined as:

Unsampled inflow = ∆Ms-∆Mi. (5)

This can be calculated for individual stream segments if the segment included a sampled inflow, or for 

the entire injection reach. If the value is negative for the 

entire study reach, however, it can still be positive for 

some individual stream segments.

In considering estimates of stream discharge and 

metal concentration at each stream site, it is possible to 

predict an error for the change in load along a stream 

segment. The error is determined by the precision of 

both discharge and chemical measurements (Taylor, 

1997), according to an equation from McKinnon 

(2002):

Load Error = (6)

where 

Qa is the discharge at the upstream site, in L/s,

∆Ca is the concentration error at the upstream site, 

in mg/L,

Ca is the concentration at the upstream site, in 

mg/L, 

∆Qa is the discharge error at the upstream site, in 

mg/L, and

0.0864 is the conversion factor from mg/s to kg/day.

Load error can be calculated for each stream site 

and compared to the change in load from that site to the 

next site downstream, ∆Ms. If ∆Ms is greater than the 

calculated load error, then there has been a significant 

change in load. Only the changes of instream load that 

are greater than the load error are included in the longitudinal profiles of sampled instream load and the 

cumulative instream load.

∆Ms CbQb CaQa = ( ) – ( ) 0.0864)

∆Mi Ci Qb Qa = ( ) – ( ) 0.0864

Qa

2

∆Ca

2 Ca2

∆Qa

2 ( ) + ( ) 0.0864
Quantification of Metal Loading 9

QUANTIFICATION OF METAL LOADING

Descriptions of synoptic sampling sites, calculated discharge, and tracer concentrations are listed in 

table 1. Results of chemical analyses for the synoptic 

samples are presented in tables 2, 3, and 4. Although 41 

stream sites were sampled, these sites define only 28 

stream segments because some samples were multiple 

samples collected across the channel at the same distance and others were replicates collected at individual 

sites. Samples that are considered to be collected from 

the main channel of flow are indicated by segment 

numbers in the “Segment” column of table 1, and data 

from these samples are used to calculate loads for 

stream segments. 

Six stream samples and one inflow sample were 

collected outside the injection reach; a footnote indicates these samples in table 1. The stream segments 

they represent are of a much different scale than that of 

the samples collected in the injection reach. Only one 

of these stream segments contained an inflow sample. 

Although there were inflows that could have been sampled in these segments, that was not an objective of this 

study. Changes in tracer concentration in these segments can still provide information about possible 

metal loading to the stream.

The precision and accuracy of metal and anion 

analyses were determined by running sets of certified 

standards and standard reference samples repeatedly. 

This allowed the calculation of single operator precision by the method suggested by Friedman and Erdmann (1982). Precision was determined as a function 

of concentration and was calculated for individual samples from a power equation in load calculations. The 

coefficient and exponent of the power equations for 

each element are listed in table 5, along with lower 

detection limits and the average accuracy of repeated 

analyses of certified standards. 

Discharge

Breakthrough of the tracer was sampled at four 

sites along the study reach (transport sites are indicated 

as T1 through T4 in table 1). The difference in plateau 

concentration at these sites indicates the dilution from 

inflows to the stream between sites (fig. 3). Bromide 

concentration varied substantially during plateau periods for the transport sites. Samples were run several 

times to determine if this was an analytical problem, 

but the results were similar each time. Because other 

tracer-injection studies have not shown this kind of 

variation in Br concentration, something peculiar about 

the water in this area of beaver ponds could have 

caused the variation. The variation did not adversely 

affect the determination of plateau concentrations, 

however. Arrival of the tracer at each transport site 

indicates the average residence time for constituents 

between sites. 

Along the entire study reach from Park City to 

Wanship, discharge increased from 71.9 to 538 L/s, for 

a total increase of 466 L/s. Discharge at the site 

upstream from the waste-water treatment plant (6,000 

m) was only 28.9 L/s, which was much less than the 

discharge of 235 L/s measured at 5,500 m. A reconnaissance of the section between the sites at 5,500 and 

6,000 m in May 2003 revealed that these two discharges are not related. The discharge at 6,000 m represents dispersed discharge of ground water to the Silver 

Creek channel after the water at 5,500 m flows in an 

irrigation diversion (fig. 1). Thus, segment S25 represents the end of the load accounting that starts at segment S1, and segment 26 represents water draining the 

piles and flood-plain deposits of mine tailings between 

these two sites. The increase in discharge at 6,500 m 

represents the discharge of the waste-water treatment 

plant as well as a substantial ground-water inflow that 

could contribute to metal loading. 

Discharge increased by 47.7 L/s through the 

Silver Maple Claims area (from 360 m to 1,017 m). 

Bromide concentrations (fig. 4) only indicated three 

increases in discharge within the Silver Maple Claims 

area. The first increase occurred between 360 m and 

398 m where the pipe draining the Silver Creek tailings 

discharged to the stream. Tracer dilution accounted for 

an increase of 42.4 L/s in that stream segment, which 

was 89 percent of the increase through the Silver Maple 

Claims area. An individual measurement of discharge 

was made at the end of the pipe by using a flow meter 

and determining the cross-sectional area at the end of 

the pipe, indicating 12.7 L/s for the discharge of the 

pipe. This is slightly higher than 8.5 and 10.5 L/s, 

which were measured in 1987 before the end of the 

pipe was under water (Mason, 1989). Thus, 30 percent 

of the increase in flow that was measured by the tracer 

was from the pipe and 70 percent was from dispersed, 

subsurface inflow.
10 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

Table 2. Physical properties of synoptic and quality-assurance samples, Silver Creek, Utah—Continued

Sample identification Source Distance 

(meters) Date Time

Specific conductance 

(microsiemens per 

centimeter at 25 

degrees Celsius)

pH 

(standard 

units)

Temperature 

(degrees 

Celsius)

SCS-0000 S 0 05/01/02 11:25 1,668 8.40 9.0

SCS-0072 S 72 05/02/02 15:00 1,621 8.90 12.0

SCS-0225 S 225 05/02/02 14:54 1,561 8.88 12.0

SCS-0265 S 265 05/02/02 14:50 1,542 8.91 11.5

SCI-0300 LBI 300 05/02/02 14:47 1,894 9.58 21.0

SCS-0360 S 360 05/02/02 14:33 1,596 8.83 13.5

SCI-0370 LBI 370 05/02/02 14:18 2,130 6.32 9.5

SCI-0375 LBI 375 05/01/02 12:05 994 7.98 12.5

SCI-0378 LBI 378 05/02/02 14:41 3,710 6.72 11.5

SCS-0398A S 398 05/02/02 14:02 1,693 7.65 13.0

SCS-0398B S 398 05/02/02 14:09 1,681 7.67 12.5

SCS-0490R S 497 05/02/02 13:56 1,788 7.69 14.0

SCS-0490R S 497 05/02/02 13:56 1,788 7.69 14.0

SCS-0498C S 498 05/02/02 13:51 1,785 7.85 14.0

SCS-0498L S 499 05/02/02 13:42 1,906 7.83 12.0

SCS-0543L S 542 05/02/02 13:33 1,861 7.96 12.5

SCS-0543C S 543 05/02/02 13:28 1,782 8.22 13.0

SCS-0543R S 544 05/02/02 13:21 1,852 7.92 12.0

SCS-0576 S 576 05/02/02 13:15 1,792 7.84 12.0

SCS-0637R S 637 05/02/02 13:08 1,773 8.55 11.5

SCS-0637L S 638 05/02/02 12:59 1,788 7.82 11.5

SCS-0684 S 684 05/02/02 12:45 1,778 7.77 11.5

SCS-0711 S 710 05/02/02 12:40 1,773 7.77 12.0

SCS-0778A S 778 05/02/02 11:52 1,836 7.77 9.0

SCS-0778B S 778 05/02/02 11:55 1,835 7.76 9.0

SCS-0832L S 831 05/02/02 11:43 1,855 7.73 9.0

SCS-0832C S 832 05/02/02 11:40 1,857 7.77 8.5

SCS-0832R S 833 05/02/02 11:24 1,870 7.76 9.0

SCS-0877 S 877 05/02/02 11:19 1,884 7.78 8.5

SCS-0940L S 940 05/02/02 10:57 1,904 7.72

SCS-0990L S 989 05/02/02 11:08 1,880 7.67 8.0

SCS-0990C S 990 05/02/02 11:15 1,883 7.61 8.0

SCI-0991 LBI 991 05/02/02 10:52 2,480 7.36 7.5

SCS-0992 S 992 05/02/02 10:49 1,906 7.73 8.0

SCS-1017 S 1,017 05/02/02 10:38 1,913 7.77 7.5

SCS-1079L S 1,079 05/02/02 10:30 1,957 7.76 8.0

SCS-1079C S 1,080 05/02/02 10:26 1,936 7.74 7.0

SCS-1079R S 1,081 05/02/02 10:23 1,931 7.74 7.0

SCI-1140 LBI 1,140 05/02/02 10:09 999 8.10 9.5

SCS-1162 S 1,162 05/02/02 10:13 1,934 7.72 6.5

SCS-1165 S 1,165 05/02/02 10:05 1,801 7.76 8.0

SCS-1212 S 1,212 05/02/02 9:55 1,920 7.68 6.0

SCS-1344A S 1,344 05/02/02 9:38 1,942 7.65 6.0

Table 2. Physical properties of synoptic and quality-assurance samples, Silver Creek, Utah

[Source: S, stream, LBI, left bank inflow]
Quantification of Metal Loading 11

The second increase of only 0.2 L/s occurred in 

segment S8 and probably was dispersed, subsurface 

inflow also. This was less than 1 percent of the 

increase. The final increase of 5.1 L/s occurred in segment S13 and accounted for 11 percent of the total. The 

largest beaver pond was present in this segment. No 

inflows were present, however, and the increase was 

likely from dispersed, subsurface inflow. 

Chemical Character of Synoptic Samples

Three distinct changes in the chemical character 

of stream water occurred along the study reach (table 

6). Upstream from the Silver Maple Claims area (segments S1 through S5), the dominant ions were Na and 

Cl, and the median pH was 8.89 (table 6, group 1; fig. 

5A). Downstream from the Silver Creek tailings discharge pipe (segment S6), Ca and SO4 concentrations 

increased (fig. 5B) and pH decreased to a median of 

7.82 (table 6; fig. 5A). Finally, at the downstream end 

of the largest beaver pond (segment S13), the concentration of most of the major ions increased slightly, but 

the increase was greatest for Na and Cl. At that same 

location, pH decreased to a median of 7.75 (table 6, 

group 3). 

Instream metal concentrations ranged from less 

than 1 μg/L for several constituents to greater than 

3,000 μg/L for Zn (fig. 6). Many samples had concentrations of Al, Fe, Mn, Sr, and Zn that exceeded 100 —

μg/L. Median concentrations of colloidal Al, Cu, Fe, 

and Pb were greater than the median dissolved concentrations, which is consistent with the high pH along the 

study reach and the normal geochemical behavior of 

these metals (Nordstrom and Alpers, 1999).

The spatial variation of metal concentrations was 

greater than the variation of the major ions. Three general patterns of variation occurred along the study 

reach. Upstream from the Silver Maple Claims area 

(segments S1 through S5), colloidal concentrations of 

Al, Cu, and Fe were relatively high, as illustrated by the 

variation of Al concentration (fig. 7). At the beginning 

of the Silver Maple Claims area, concentrations of 

these metals decreased, possibly as a result of flow 

through thick vegetation in the wetland. Colloidal concentrations of these metals, however, continued 

through the wetland at a lower level. 

A second pattern of concentration was important 

for most metals and SO4 (fig. 5B). The pattern was distinguished by an increase in concentration downstream 

from the Silver Creek tailings discharge pipe at segment S6; the concentration of Zn doubled along that 

segment (fig. 8). A second increase in Zn concentration 

occurred downstream from the largest beaver pond 

(segment S13). A similar increase occurred for arsenic 

(As), Fe, Pb, Mn, and Sr, but not for Cd or Cu (table 4). 

Total-recoverable Zn remained nearly constant along 

the remainder of the injection study reach, but a part of 

the Zn was transformed from the dissolved to the colloidal phase because of the high pH of the stream (fig. 

8). Note that Zn concentrations exceeded aquatic-life 

standards along the entire study reach; the standards 

are indicated on figure 8.

SCS-1344B S 1,344 05/02/02 9:40 1,939 7.69 6.0

SCS-1380 S 1,380 05/02/02 9:30 1,801 7.75 6.0

SCS-1420 S 1,420 05/02/02 9:25 1,923 7.78 6.0

SCS-5000A S 5,000 05/01/02 15:45 1,463 8.03 12.0

SCS-5000B S 5,500 05/01/02 15:35 1,449 8.11 12.0

SCS-6000A S 6,000 05/01/02 15:00 1,835 7.69

SCS-6000B S 6,500 05/01/02 14:10 1,790 7.86 11.0

SCS-7000 S 7,000 05/01/02 13:05 710 8.14 8.5

SCF1-BLNK QA 8,888 05/02/02

SCF2-BLNK QA 8,888 05/02/02

SCL-BLNK QA 8,888 05/02/02

Table 2. Physical properties of synoptic and quality-assurance samples, Silver Creek, Utah—Continued

Sample identification Source Distance 

(meters) Date Time

Specific conductance 

(microsiemens per 

centimeter at 25 

degrees Celsius)

pH 

(standard 

units)

Temperature 

(degrees 

Celsius)
12 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

Table 3. Results of chemical analyses of major constituents in synoptic and quality-assurance samples, Silver Creek, Utah—Continued

Sample 

identification Treatment Calcium (mg/L)

Magnesium 

(mg/L)

Sodium 

(mg/L)

Potassium 

(mg/L)

Alkalinity 

as CaCO3

(mg/L)

Sulfate 

(mg/L)

Chloride 

(mg/L)

Fluoride 

(mg/L)

Silica, as Si 

(mg/L)

SCS-0000 FA 110 25.0 172 2.7 101 135 366 0.93 5.22

SCS-0000 RA 96.5 23.4 146 2.5 101 135 366 .93 5.16

SCS-0072 FA 105 24.3 167 2.8 77.4 117 377 1.28 5.56

SCS-0072 RA 106 25.3 164 2.7 77.4 117 377 1.28 6.61

SCS-0225 FA 106 24.2 153 2.6 99.4 145 319 .95 5.35

SCS-0225 RA 103 23.8 143 2.8 99.4 145 319 .95 6.23

SCS-0265 FA 94.0 22.0 131 2.5 84.4 127 280 .88 4.52

SCS-0265 RA 100 23.7 145 2.8 84.4 127 280 .88 6.13

SCI-0300 FA 92.7 23.9 217 3.4 40.8 152 430 1.24 1.45

SCI-0300 RA 89.5 24.1 203 3.3 40.8 152 430 1.24 1.26

SCS-0360 FA 109 24.3 160 2.9 96.4 149 333 .92 4.98

SCS-0360 RA 108 24.5 150 2.9 96.4 149 333 .92 5.64

SCI-0370 FA 288 40.1 118 5.7 66.9 638 305 1.99 12.0

SCI-0370 RA 292 41.7 116 6.0 66.9 638 305 1.99 16.1

SCI-0375 FA 104 35.4 28.9 1.5 136 214 80.8 .52 4.64

SCI-0375 RA 116 38.4 32.1 1.8 136 214 80.8 .52 7.13

SCI-0378 FA 319 59.1 399 7.6 112 785 728 3.32 10.7

SCI-0378 RA 334 60.5 415 7.1 112 785 728 3.32 11.1

SCS-0398A FA 132 26.9 151 3.2 91.1 219 322 1.04 6.00

SCS-0398A RA 128 26.5 142 3.3 91.1 219 322 1.04 6.45

SCS-0398B FA 118 24.1 125 3.1 74.7 183 287 1.04 4.82

SCS-0398B RA 122 24.6 129 2.8 74.7 183 287 1.04 5.68

SCS-0490R FA 136 27.8 164 3.3 93.2 222 348 1.05 5.40

SCS-0490R RA 133 27.2 153 3.2 93.2 222 348 1.05 5.75

SCS-0498C FA 138 28.2 167 3.2 92.0 213 365 1.06 5.40

SCS-0498C RA 130 27.4 158 3.2 92.0 213 365 1.06 5.44

SCS-0498L FA 120 25.0 160 3.3 85.8 185 339 1.41 4.30

SCS-0498L RA 125 25.6 168 3.3 85.8 185 339 1.41 5.02

SCS-0543L FA 133 26.9 186 3.5 93.9 204 387 1.14 5.21

SCS-0543L RA 125 26.3 171 3.3 93.9 204 387 1.14 5.26

SCS-0543C FA 112 24.3 143 3.0 76.9 178 308 1.13 4.27

SCS-0543C RA 114 25.1 145 3.1 76.9 178 308 1.13 4.40

SCS-0543R FA 125 26.1 147 3.1 81.9 191 328 1.26 4.43

SCS-0543R RA 125 26.8 151 3.1 81.9 191 328 1.26 5.26

SCS-0576 FA 140 28.6 173 3.5 98.1 220 370 1.17 5.47

SCS-0576 RA 123 26.6 146 3.0 98.1 220 370 1.17 4.83

SCS-0637R FA 138 27.4 163 3.3 94.6 218 351 1.10 5.51

SCS-0637R RA 127 26.9 153 3.3 94.6 218 351 1.10 5.47

SCS-0637L FA 120 24.9 141 3.4 82.5 190 308 1.15 4.59

SCS-0637L RA 127 27.6 158 3.2 82.5 190 308 1.15 5.28

SCS-0684 FA 122 25.0 142 2.9 86.7 190 311 1.10 4.36

SCS-0684 RA 120 24.9 137 2.9 86.7 190 311 1.10 4.58

SCS-0711 FA 121 25.3 139 3.0 80.9 190 308 1.10 4.25

SCS-0711 RA 122 25.2 144 3.0 80.9 190 308 1.10 4.74

Table 3. Results of chemical analyses of major constituents in synoptic and quality-assurance samples, Silver Creek, Utah

[Treatment: FA, 0.45-micrometer filtered, RA, total recoverable; mg/L, milligrams per liter]
Quantification of Metal Loading 13

SCS-0778A FA 135 28.0 166 2.9 98.5 210 356 1.27 5.73

SCS-0778A RA 132 28.1 163 3.1 98.5 210 356 1.27 5.19

SCS-0778B FA 135 28.9 172 3.4 99.9 214 364 1.24 5.39

SCS-0778B RA 131 28.3 160 2.8 99.9 214 364 1.24 5.21

SCS-0832L FA 124 26.0 147 3.0 89.0 190 324 1.26 4.18

SCS-0832L RA 126 27.9 163 3.0 89.0 190 324 1.26 4.96

SCS-0832C FA 127 27.3 154 2.8 91.4 194 337 1.18 4.36

SCS-0832C RA 127 28.5 165 3.2 91.4 194 337 1.18 5.06

SCS-0832R FA 138 29.0 178 3.5 112 217 369 1.25 5.03

SCS-0832R RA 124 27.7 158 3.0 112 217 369 1.25 4.86

SCS-0877 FA 144 29.6 187 3.4 105 227 393 1.32 5.16

SCS-0877 RA 124 28.6 166 3.2 105 227 393 1.32 4.96

SCS-0940L FA 141 29.1 182 3.6 102 221 384 1.33 5.26

SCS-0940L RA 132 29.0 169 3.2 102 221 384 1.33 5.16

SCS-0990L FA 129 26.6 152 3.0 86.6 181 349 1.15 4.23

SCS-0990L RA 130 28.6 170 3.1 86.6 181 349 1.15 5.03

SCS-0990C FA 129 27.0 154 3.0 92.6 195 339 1.26 4.40

SCS-0990C RA 127 28.5 167 3.2 92.6 195 339 1.26 5.16

SCI-0991 FA 175 36.7 292 4.6 138 291 569 2.81 6.68

SCI-0991 RA 172 35.2 268 4.4 138 291 569 2.81 7.03

SCS-0992 FA 145 30.1 181 3.3 106 224 388 1.37 5.87

SCS-0992 RA 136 29.4 177 3.2 106 224 388 1.37 5.28

SCS-1017 FA 131 27.9 159 3.1 94.9 199 348 1.42 4.28

SCS-1017 RA 142 29.9 175 3.4 94.9 199 348 1.42 5.56

SCS-1079L FA 147 32.7 189 3.3 108 230 405 1.38 5.18

SCS-1079L RA 135 29.9 166 3.2 108 230 405 1.38 4.53

SCS-1079C FA 127 27.1 157 3.2 91.2 194 341 1.23 4.21

SCS-1079C RA 125 27.0 158 3.1 91.2 194 341 1.23 4.69

SCS-1079R FA 126 26.8 157 3.0 91.3 193 341 1.40 4.25

SCS-1079R RA 137 29.5 178 3.2 91.3 193 341 1.40 5.18

SCI-1140 FA 105 33.2 30.6 1.5 129 192 99.0 .54 4.74

SCI-1140 RA 107 36.1 31.2 1.6 129 192 99.0 .54 5.16

SCS-1162 FA 125 27.6 157 3.0 94.2 195 337 1.31 4.34

SCS-1162 RA 140 29.0 171 3.3 94.2 195 337 1.31 4.95

SCS-1165 FA 123 29.5 130 2.7 103 195 291 1.07 3.88

SCS-1165 RA 141 34.1 149 3.3 103 195 291 1.07 5.19

SCS-1212 FA 128 27.8 160 2.9 94.6 198 345 1.38 4.29

SCS-1212 RA 143 30.1 178 3.3 94.6 198 345 1.38 5.25

SCS-1344A FA 147 31.2 188 3.7 106 232 399 1.33 5.08

SCS-1344A RA 142 29.6 172 3.3 106 232 399 1.33 4.94

SCS-1344B FA 129 27.3 161 3.3 92.0 200 346 1.39 4.31

SCS-1344B RA 136 30.1 177 3.1 92.0 200 346 1.39 5.02

SCS-1380 FA 128 26.8 158 2.7 91.0 199 341 1.38 4.44

SCS-1380 RA 140 29.2 169 3.3 91.0 199 341 1.38 4.86

SCS-1420 FA 143 30.9 189 3.5 90.6 196 432 1.42 5.42

Table 3. Results of chemical analyses of major constituents in synoptic and quality-assurance samples, Silver Creek, Utah—Continued

Sample 

identification Treatment Calcium 

(mg/L)

Magnesium 

(mg/L)

Sodium 

(mg/L)

Potassium 

(mg/L)

Alkalinity 

as CaCO3

(mg/L)

Sulfate 

(mg/L)

Chloride 

(mg/L)

Fluoride 

(mg/L)

Silica, as Si 

(mg/L)
14 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

The final pattern of concentration was unique to 

the variation of Na and Cl and consisted in a nearly 

constant concentration along the injection reach (fig. 

9). The concentration of Na and Cl correlated with the 

high concentrations of salt on the highway next to the 

Silver Maple Claims area. The equivalents of Cl actually exceed the equivalents of Na in the stream. The 

excess Cl balances some of the Ca and Mg, indicating 

that these alkaline-earth chlorides may be used as road 

salt along with NaCl. 

Only five inflow samples were collected along 

the study reach (table 1). This small number could be a 

result of the high flow that may have covered some 

inflows that would be visible at a lower stage of the 

stream. The Pace-Homer Ditch (375 m) was sampled 

across the highway from the injection study reach. The 

inflow sample at 1,140 m represented water flowing to 

the stream from a breach in the Pace-Homer Ditch, and 

this relatively small flow started mixing with the 

stream at about 1,165 m. Two inflow samples at 378 m 

and 991 m were collected from small ponds that had no 

visible connection to the flow in the stream. These may 

represent water that drains from tailings piles along the 

study reach. For purposes of quantifying loads, the 

most important inflow sample was the end of the 

ground-water drain pipe from the Silver Creek tailings 

(sample PS-DR-1 of Mason, 1989). Obtaining a sample 

from the Prospector pipe was complicated because the 

discharge from the end of the pipe was below the surface of a pond at the upstream end of the BLM property 

(fig. 10).

The inflow sample from the Silver Creek tailings 

pipe had a Br concentration of 0.77 mg/L, indicating 

that the sample included some fraction of pond water. 

This could have happened as the vertical-integrating 

sampler was lowered from the surface to the end of the 

pipe. Assuming that the pipe sample should have had a 

Br concentration closer to a background concentration 

of 0.06 mg/L, and given the plateau concentration of Br 

at the upstream end of the pond of 4.21 mg/L, it is possible to determine the fraction of pond water in the 

sample:

(4.21)x+(0.06)y=0.77

x+y=1

x=0.17; y=0.83 (7)

where

x is the fraction of pond water, and 

y is the fraction of pipe discharge.

SCS-1420 RA 145 31.2 186 3.2 90.6 196 432 1.42 5.92

SCS-5000A FA 119 35.0 87.8 2.3 117 223 204 .94 3.37

SCS-5000A RA 121 34.5 88.2 2.3 117 223 204 .94 3.62

SCS-5000B FA 123 34.5 80.5 2.3 120 230 191 .94 3.87

SCS-5000B RA 125 36.4 82.6 2.5 120 230 191 .94 4.37

SCS-6000A FA 204 51.9 98.4 3.5 143 461 333 1.40 11.1

SCS-6000A RA 202 52.3 100 3.7 143 461 333 1.40 11.5

SCS-6000B FA 146 40.3 145 9.1 158 333 364 1.24 10.8

SCS-6000B RA 151 38.7 139 8.3 158 333 364 1.24 11.9

SCS-7000 FA 60.0 12.8 40.5 3.1 113 76 184 .08 8.70

SCS-7000 RA 61.9 13.9 41.2 3.1 113 76 184 .08 10.3

SCF1-BLNK FA .088 .029 .067 .040 .05

SCF1-BLNK RA .088 .029 .067 .015 .05

SCF2-BLNK FA .088 .029 .067 .015 .05

SCF2-BLNK RA .088 .029 .067 .015 .05

SCL-BLNK .03 .02 .01

SCT-BLNK RA .088 .029 .067 .015 .05

Table 3. Results of chemical analyses of major constituents in synoptic and quality-assurance samples, Silver Creek, Utah—Continued

Sample 

identification Treatment Calcium (mg/L)

Magnesium 

(mg/L)

Sodium 

(mg/L)

Potassium 

(mg/L)

Alkalinity 

as CaCO3

(mg/L)

Sulfate 

(mg/L)

Chloride 

(mg/L)

Fluoride 

(mg/L)

Silica, as Si 

(mg/L)
Quantification of Metal Loading 15

 

Figure 3. Variation of bromide concentration at transport sites with time, Silver Creek, Utah, April and May 2002.

4/29/2002 06:004/30/2002 06:00

5/1/2002 06:005/2/2002 06:005/3/2002 06:005/4/2002 06:005/5/2002 06:00

5/6/2002 06:00

0

1

2

3

4

5

6

End of injection

End of synoptic sampling

BROMIDE CONCENTRATION, IN MILLIGRAMS PER LITER

Start of synoptic sampling

DATE AND TIME, IN HOURS

Upstream from injection reach

Site T1

Site T2

Site T3

Site T4

Start of injection
16 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

Table 4. Results of chemical analyses of trace constituents in synoptic and quality-assurance samples, Silver Creek, Utah

[Source: S, stream; LBI, left bank inflow; Treatment: FA, 0.45-micrometer filtered, RA, total recoverable; μg/L, micrograms per liter]

Sample 

identification Treatment Aluminum (μg/L)

Arsenic

(μg /L)

Barium

(μg /L)

Cadmium

(μg /L)

Chromium 

(μg /L)

Cobalt 

(μg /L)

Copper 

(μg /L)

Iron

(μg /L)

Lead 

(μg /L)

SCS-0000 FA 38.1 2.80 110 7.18 0.13 0.34 2.59 5.37 0.66

SCS-0000 RA 302.2 3.81 120 8.80 .45 .47 4.57 343 15.0

SCS-0072 FA 41.6 2.98 103 2.69 .13 .36 3.14 8.92 .68

SCS-0072 RA 423.9 4.86 110 6.65 .71 .53 6.83 477 14.3

SCS-0225 FA 33.4 3.59 103 3.68 .14 .29 3.13 5.56 .70

SCS-0225 RA 436.8 5.01 106 7.42 .70 .56 6.98 470 14.4

SCS-0265 FA 27.2 2.99 101 3.62 .13 .32 2.83 4.32 .63

SCS-0265 RA 452.1 5.10 120 7.67 .72 .53 6.92 480 15.6

SCI-0300 FA 37.0 7.54 109 .10 .15 .21 2.56 11.0 .88

SCI-0300 RA 217.3 8.08 112 2.10 .45 .28 3.78 321 19.7

SCS-0360 FA 33.5 2.95 96.2 3.46 .12 .31 2.83 3.90 1.24

SCS-0360 RA 321.6 4.60 104 6.67 .50 .47 5.21 330 14.0

SCI-0370 FA 36.0 1.08 23.8 34.3 .11 .88 1.35 54.0 .47

SCI-0370 RA 2,469.5 76.0 45.4 43.6 4.21 3.25 29.2 8,859 182

SCI-0375 FA 41.1 7.10 48.6 .22 .15 .38 .80 4.81 .60

SCI-0375 RA 451.0 8.47 49.2 .40 .61 .49 2.53 418 12.4

SCI-0378 FA 119.2 6.90 62.4 26.2 .14 12.7 13.3 2,600 4.03

SCI-0378 RA 113.0 11.5 55.9 26.9 .12 15.1 11.2 4,533 17.1

SCS-0398A FA 33.6 2.54 80.3 8.08 .10 .35 2.07 4.40 1.03

SCS-0398A RA 317.3 3.49 88.6 12.1 .51 .51 5.11 348 15.1

SCS-0398B FA 23.2 2.42 90.5 9.47 .11 .46 2.18 3.78 .91

SCS-0398B RA 263.5 3.86 89.1 11.9 .49 .45 5.17 314 15.6

SCS-0490R FA 31.5 2.59 86.2 7.53 .09 .31 1.93 4.58 1.03

SCS-0490R RA 170.2 2.42 104 11.4 .32 .41 3.95 196 9.28

SCS-0498C FA 30.0 2.70 93.7 6.02 .09 .35 2.05 6.26 .86

SCS-0498C RA 156.9 3.70 97.0 9.43 .30 .39 3.84 206 9.90

SCS-0498L FA 26.9 9.67 92.9 5.77 .06 .85 2.17 19.5 .40

SCS-0498L RA 109.1 5.70 84.9 7.97 .21 .82 4.00 434 9.27

SCS-0543L FA 32.5 2.43 87.0 3.35 .05 .53 1.43 17.6 .39

SCS-0543L RA 217.3 5.29 88.6 7.27 .40 .58 4.98 569 17.2

SCS-0543C FA 79.1 2.38 84.6 3.77 .11 .31 1.83 9.35 .53

SCS-0543C RA 70.5 3.88 90.5 5.72 .21 .30 2.94 195 7.00

SCS-0543R FA 25.4 2.65 94.6 8.04 .09 .33 1.69 4.58 1.36

SCS-0543R RA 189.5 3.00 95.3 10.6 .32 .37 3.68 222 13.5

SCS-0576 FA 37.5 2.14 77.5 5.45 .08 .30 1.73 7.22 .84

SCS-0576 RA 98.4 3.22 84.1 8.73 .24 .35 3.61 199 9.81

SCS-0637R FA 29.0 2.09 85.6 5.55 .08 .31 1.45 6.90 .84

SCS-0637R RA 137.9 3.43 90.3 8.90 .28 .41 3.52 230 10.2

SCS-0637L FA 40.1 1.80 76.3 4.30 .07 .28 1.39 8.43 .60

SCS-0637L RA 98.1 3.90 96.5 8.23 .23 .37 3.11 246 10.2

SCS-0684 FA 24.3 2.34 88.7 5.03 .07 .26 1.37 7.57 .62

SCS-0684 RA 85.9 3.46 92.6 7.36 .23 .36 3.15 209 9.41

SCS-0711 FA 24.1 1.72 89.6 4.59 .08 .20 1.52 5.44 .91

SCS-0711 RA 104.6 3.25 82.4 6.56 .24 .25 3.13 189 13.0

SCS-0778A FA 29.0 2.58 82.5 3.56 .05 .36 1.22 11.0 .75

SCS-0778A RA 115.5 4.39 96.3 7.67 .26 .42 3.99 265 17.3

SCS-0778B FA 34.1 1.89 86.0 3.83 .05 .35 1.32 11.2 .74

SCS-0778B RA 119.2 4.30 87.8 7.03 .21 .41 3.88 280 19.1
Quantification of Metal Loading 17

Table 4. Results of chemical analyses of trace constituents in synoptic and quality-assurance samples, Silver Creek, Utah—Continued

Sample 

identification Treatment Lithium(μg /L)

Manganese 

(μg/L)

Molybdenum

(μg /L)

Nickel

(μg /L)

Silver 

(μg /L)

Strontium

(μg /L)

Vanadium

(μg /L)

Zinc

(μg /L)

SCS-0000 FA 8.84 140 1.49 2.05 0.08 415 0.70 963

SCS-0000 RA 8.36 169 1.41 1.99 .47 388 1.12 1,038

SCS-0072 FA 8.93 121 1.75 1.30 .08 429 .94 259

SCS-0072 RA 9.21 171 1.75 1.77 .36 456 1.62 741

SCS-0225 FA 9.31 121 1.82 1.44 .08 420 .94 358

SCS-0225 RA 9.31 160 1.88 2.12 .33 461 1.64 876

SCS-0265 FA 8.07 108 1.82 1.21 .08 462 .83 327

SCS-0265 RA 9.64 167 1.96 2.17 .39 407 1.57 874

SCI-0300 FA 10.3 24.0 3.37 1.03 .08 466 2.41 17.0

SCI-0300 RA 12.1 66.8 3.32 1.59 .14 453 2.99 214

SCS-0360 FA 7.50 124 1.59 1.43 .08 465 .88 357

SCS-0360 RA 9.53 161 1.62 2.00 .37 407 1.35 830

SCI-0370 FA 17.7 615 .17 15.8 .08 602 .23 7,930

SCI-0370 RA 18.7 1,010 .53 19.4 7.21 556 9.69 8,557

SCI-0375 FA 8.84 23.4 2.20 1.08 .08 769 1.14 57.7

SCI-0375 RA 10.5 49.0 2.32 1.27 .10 727 1.91 72.0

SCI-0378 FA 32.1 3,220 1.14 18.5 .08 692 .02 17,068

SCI-0378 RA 37.3 3,244 1.34 21.5 .11 765 .09 17,419

SCS-0398A FA 8.33 206 1.38 3.36 .08 472 .67 1,646

SCS-0398A RA 10.3 226 1.41 3.95 .41 455 1.17 1,882

SCS-0398B FA 9.48 182 1.56 4.25 .08 480 .77 1,560

SCS-0398B RA 9.18 217 1.37 4.84 .36 426 1.18 1,720

SCS-0490R FA 8.75 175 1.28 2.95 .08 476 .65 1,528

SCS-0490R RA 9.55 187 1.45 4.12 .23 497 1.01 1,651

SCS-0498C FA 10.5 167 1.36 3.19 .08 448 .72 1,240

SCS-0498C RA 10.6 180 1.35 3.32 .21 456 1.01 1,361

SCS-0498L FA 10.3 391 1.93 3.57 .08 493 .33 1,422

SCS-0498L RA 11.9 402 1.74 3.14 .17 430 .65 1,631

SCS-0543L FA 9.78 299 1.69 2.93 .08 490 .34 1,201

SCS-0543L RA 12.4 290 1.63 4.25 .22 430 .97 1,366

SCS-0543C FA 11.4 127 1.57 2.96 .08 461 .63 863

SCS-0543C RA 10.4 135 1.50 2.51 .11 445 .78 990

SCS-0543R FA 8.69 158 1.20 2.94 .08 473 .55 1,378

SCS-0543R RA 8.85 181 1.19 3.21 .23 435 .86 1,601

SCS-0576 FA 8.66 196 1.30 2.89 .08 478 .48 1,484

SCS-0576 RA 9.11 189 1.35 3.73 .13 454 .74 1,445

SCS-0637R FA 8.26 175 1.32 3.10 .08 438 .47 1,455

SCS-0637R RA 12.7 184 1.46 4.72 .16 471 .87 1,608

SCS-0637L FA 8.81 182 1.34 2.89 .08 485 .39 1,314

SCS-0637L RA 10.7 208 1.49 3.90 .17 457 .68 1,580

SCS-0684 FA 9.30 148 1.38 3.05 .08 506 .41 1,333

SCS-0684 RA 11.5 163 1.53 4.42 .15 509 .75 1,402

SCS-0711 FA 9.74 104 1.51 3.28 .08 469 .50 1,152

SCS-0711 RA 9.75 127 1.46 4.85 .16 402 .73 1,248

SCS-0778A FA 8.91 241 1.37 3.37 .08 503 .29 1,882

SCS-0778A RA 11.1 250 1.54 4.76 .20 480 .62 1,938

SCS-0778B FA 9.14 250 1.43 3.89 .08 504 .31 1,819

SCS-0778B RA 9.93 247 1.45 4.27 .17 502 .59 1,955
18 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

Table 4. Results of chemical analyses of trace constituents in synoptic and quality-assurance samples, Silver Creek, Utah—Continued

Sample 

identification Treatment Aluminum (μg/L)

Arsenic

(μg /L)

Barium

(μg /L)

Cadmium 

(μg /L)

Chromium 

(μg /L)

Cobalt 

(μg /L)

Copper 

(μg /L)

Iron

(μg /L)

Lead 

(μg /L)

SCS-0832L FA 28.6 2.75 81.5 2.64 .04 .37 1.13 8.81 .86

SCS-0832L RA 133.0 5.59 101 5.54 .25 .44 3.82 303 21.7

SCS-0832C FA 35.1 2.95 93.6 2.43 .04 .39 .96 10.3 .72

SCS-0832C RA 129.5 5.18 89.7 4.92 .21 .40 3.13 308 22.7

SCS-0832R FA 42.3 2.90 75.5 1.81 .04 .35 1.04 10.6 .72

SCS-0832R RA 103.7 5.11 89.1 4.33 .19 .38 2.78 258 18.0

SCS-0877 FA 43.1 3.19 80.3 2.32 .05 .29 1.28 71.0 3.53

SCS-0877 RA 81.0 4.08 87.4 3.54 .18 .33 2.24 219 11.8

SCS-0940L FA 27.1 3.19 80.0 1.10 .03 .34 .92 13.5 .74

SCS-0940L RA 185.9 5.67 93.0 4.01 .31 .45 4.39 382 29.1

SCS-0990L FA 25.2 3.13 96.5 2.20 .04 .34 .97 9.20 .73

SCS-0990L RA 117.0 5.44 87.5 4.82 .21 .40 3.08 281 20.2

SCS-0990C FA 28.1 2.51 94.1 2.20 .03 .35 1.14 38.1 .63

SCS-0990C RA 97.7 5.27 83.6 4.35 .22 .40 2.96 302 15.8

SCI-0991 FA 30.5 1.10 20.0 46.1 .01 .10 1.93 1.51 1.80

SCI-0991 RA 75.9 1.40 18.3 43.8 .12 .11 2.49 54.0 5.70

SCS-0992 FA 30.0 2.82 89.4 1.31 .03 .37 1.01 18.0 .64

SCS-0992 RA 126.7 4.73 97.1 3.81 .23 .38 3.24 339 22.5

SCS-1017 FA 24.8 2.33 84.4 1.29 .03 .41 1.04 15.7 .59

SCS-1017 RA 172.5 7.00 104 4.71 .34 .48 4.88 422 29.5

SCS-1079L FA 33.8 2.88 79.4 1.82 .03 .17 1.34 6.71 .67

SCS-1079L RA 52.4 3.62 77.9 3.14 .11 .19 1.87 145 7.66

SCS-1079C FA 26.0 3.51 88.2 1.14 .03 .41 .74 12.1 .73

SCS-1079C RA 155.3 6.84 97.1 4.69 .34 .50 5.12 427 32.0

SCS-1079R FA 24.2 6.39 84.0 1.23 .02 .33 .92 17.0 .69

SCS-1079R RA 110.8 4.94 87.4 3.43 .22 .37 3.09 288 17.5

SCI-1140 FA 40.4 5.43 43.8 .33 .19 .40 .86 3.67 .53

SCI-1140 RA 90.9 6.35 45.4 .38 .27 .38 1.47 110 5.01

SCS-1162 FA 26.4 3.18 91.9 1.43 .04 .36 1.16 11.0 .87

SCS-1162 RA 102.1 5.13 90.9 3.85 .19 .38 3.22 244 14.5

SCS-1165 FA 25.0 3.01 74.0 1.90 .05 .12 1.60 5.93 .92

SCS-1165 RA 165.6 5.06 76.2 3.52 .30 .22 3.57 271 24.8

SCS-1212 FA 29.1 2.77 93.5 1.44 .04 .35 1.22 18.6 .89

SCS-1212 RA 118.7 3.33 89.7 8.58 .27 .38 3.25 290 11.4

SCS-1344A FA 35.3 3.01 73.5 1.80 .03 .32 1.56 9.27 1.66

SCS-1344A RA 86.9 5.20 85.4 3.64 .16 .32 3.16 232 20.3

SCS-1344B FA 26.4 3.54 87.3 1.91 .03 .33 1.33 7.08 1.49

SCS-1344B RA 90.5 4.99 81.4 3.92 .17 .38 3.53 233 17.6

SCS-1380 FA 30.2 2.91 77.7 2.67 .02 .61 1.74 8.30 2.66

SCS-1380 RA 104.0 6.39 87.2 6.18 .27 .73 8.47 318 37.5

SCS-1420 FA 37.9 3.21 93.2 2.83 .02 .58 1.82 32.2 2.95

SCS-1420 RA 135.3 6.16 86.2 5.18 .26 .72 7.47 357 41.1

SCS-5000A FA 31.5 2.54 59.8 3.18 .06 .41 2.60 16.4 1.85

SCS-5000A RA 60.4 5.33 63.4 3.93 .10 .34 4.39 243 27.7

SCS-5000B FA 32.6 2.97 59.7 2.14 .06 .25 2.81 10.9 4.11

SCS-5000B RA 153.8 5.23 61.3 3.25 .21 .30 6.15 319 41.4

SCS-6000A FA 40.0 8.87 57.9 12.6 .04 1.20 6.19 17.0 1.34

SCS-6000A RA 32.0 13.7 55.0 13.8 .04 .99 7.05 219 10.4
Quantification of Metal Loading 19

Table 4. Results of chemical analyses of trace constituents in synoptic and quality-assurance samples, Silver Creek, Utah—Continued

Sample 

identification Treatment Lithium(μg /L)

Manganese 

(μg/L)

Molybdenum

(μg /L)

Nickel

(μg /L)

Silver 

(μg /L)

Strontium

(μg /L)

Vanadium

(μg /L)

Zinc

(μg /L)

SCS-0832L FA 9.48 254 1.35 3.66 .08 536 .28 1,688

SCS-0832L RA 10.7 279 1.54 4.93 .18 557 .63 1,969

SCS-0832C FA 9.70 263 1.39 3.59 .08 492 .25 1,695

SCS-0832C RA 9.82 284 1.33 3.49 .20 433 .48 1,948

SCS-0832R FA 9.00 302 1.31 3.37 .08 516 .24 1,794

SCS-0832R RA 9.53 284 1.44 3.71 .11 467 .48 1,846

SCS-0877 FA 8.85 258 1.31 3.54 .08 502 .28 1,741

SCS-0877 RA 11.0 246 1.38 4.56 .09 474 .43 1,824

SCS-0940L FA 9.00 300 1.38 3.66 .08 528 .22 1,674

SCS-0940L RA 10.9 299 1.42 4.03 .24 463 .58 1,869

SCS-0990L FA 9.16 263 1.34 3.37 .08 472 .23 1,685

SCS-0990L RA 9.61 296 1.41 4.17 .17 501 .49 2,008

SCS-0990C FA 9.61 245 1.55 4.08 .08 521 .27 1,643

SCS-0990C RA 10.1 264 1.45 4.08 .16 471 .48 1,889

SCI-0991 FA 14.6 78.3 .83 2.13 .08 601 .02 8,598

SCI-0991 RA 17.0 82.9 .85 3.06 .08 517 .07 8,421

SCS-0992 FA 9.53 297 1.47 3.75 .08 496 .22 1,741

SCS-0992 RA 10.7 308 1.47 3.83 .20 464 .48 1,899

SCS-1017 FA 10.1 293 1.51 4.02 .08 508 .22 1,570

SCS-1017 RA 11.3 337 1.60 4.83 .21 581 .65 1,957

SCS-1079L FA 12.3 158 1.38 3.40 .08 551 .17 1,453

SCS-1079L RA 11.4 157 1.31 3.00 .08 522 .27 1,465

SCS-1079C FA 9.43 301 1.28 3.42 .08 481 .18 1,533

SCS-1079C RA 11.1 318 1.52 4.87 .24 565 .66 1,752

SCS-1079R FA 9.64 276 1.48 3.80 .08 522 .20 1,552

SCS-1079R RA 10.7 289 1.45 4.47 .14 559 .42 1,817

SCI-1140 FA 11.2 26.1 2.05 1.22 .08 814 1.12 70.0

SCI-1140 RA 8.60 46.1 1.96 1.69 .08 719 1.14 82.1

SCS-1162 FA 10.8 249 1.67 4.27 .08 525 .25 1,485

SCS-1162 RA 11.2 282 1.63 4.09 .13 513 .48 1,711

SCS-1165 FA 9.67 81.7 1.40 2.46 .08 608 .31 1,159

SCS-1165 RA 9.85 146 1.53 3.25 .23 570 .71 1,426

SCS-1212 FA 9.91 246 1.62 3.92 .08 528 .23 1,490

SCS-1212 RA 10.3 281 1.44 3.51 .19 470 .79 1,859

SCS-1344A FA 9.28 275 1.41 3.27 .08 532 .17 1,650

SCS-1344A RA 10.2 263 1.41 3.19 .14 441 .32 1,697

SCS-1344B FA 9.77 241 1.43 3.14 .08 502 .18 1,463

SCS-1344B RA 11.0 271 1.46 4.38 .13 557 .42 1,751

SCS-1380 FA 9.24 259 1.44 3.56 .08 507 .19 1,629

SCS-1380 RA 10.9 279 1.67 4.01 .29 518 .49 1,881

SCS-1420 FA 9.47 287 1.44 3.39 .08 507 .18 1,875

SCS-1420 RA 11.0 305 1.55 4.44 .28 563 .47 1,950

SCS-5000A FA 11.3 119 2.33 2.02 .08 776 .36 716

SCS-5000A RA 11.2 146 2.21 2.01 .14 661 .51 819

SCS-5000B FA 12.0 112 2.28 1.90 .08 844 .31 673

SCS-5000B RA 12.4 139 2.08 1.86 .19 701 .57 789

SCS-6000A FA 20.3 433 2.93 3.87 .08 1,182 .23 3,736

SCS-6000A RA 20.7 448 2.60 3.72 .10 972 .24 3,880
20 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

These fractions allow for a correction of the measured concentrations to make them representative of 

the undiluted pipe water. Corrected concentrations are 

listed in table 7. This is important for accurate calculation of load from the pipe.

Mass Loading

Mass-loading profiles were prepared according 

to the methods described by Kimball and others (2002), 

but several considerations were necessary for these 

data. First, load was calculated only for those sites that 

were judged to be in the main part of the flow (these 

sites are indicated by segment numbers in table 1). This 

was a subjective field observation when two or three 

samples were collected across the stream channel at 

essentially the same downstream distance along the 

study reach (fig. 2). Second, the calculated inflow load 

for the Silver Creek tailings discharge (370 m) was calculated from the measured discharge at the end of the 

pipe (table 1) and the adjusted concentrations of the 

constituents (table 5). This inflow load was comparable 

but somewhat greater than the instream load for most 

constituents in the segment from 360 m to 398 m that 

receives the Silver Creek tailings discharge. Third, 

loads calculated at 5,500 m and 6,000 m do not represent downstream change. The load at 5,500 m essentially is the end of accounting for the upstream load 

(segment S25). The load at 6,000 m represents the 

input from ground water downstream from the diversion (segment S26). The difference in constituent load 

between 6,000 m and 6,500 m, however, does represent 

a change that principally resulted from two inflows. 

One of the inflows was from the waste-water treatment 

plant and the other was from ground-water drainage to 

the stream that had a high specific-conductance value, 

but neither inflow was sampled. Finally, the comparison of load calculated at 6,500 m and 7,000 m is not 

certain (segment S27). The stream between the two 

sites was not studied in detail, but the net change 

between 6,500 m and 7,000 m is reported to give an 

indication of changes downstream (segment S28).

Load calculations for selected constituents are 

summarized in table 8. These values represent only the 

positive or negative changes of instream load for individual segments. Segments where the five greatest 

loads occur for each constituent are indicated by numbers in parentheses in table 8. If no value is listed for a 

segment in the table, the change in load for that segment was less than the load error calculated from equation 6. In table 8, and in the figures representing loads, 

the change of instream load that might be attributed to a 

particular inflow is accounted for by the change in load 

for the segment that contains the inflow. For example, 

the instream load from the Silver Creek tailings discharge pipe is accounted for by segment S6. That is 

why there are only stream sites listed in table 8.

The first of three patterns among the constituent 

load profiles along the study reach was typical of Cd 

and Zn and is illustrated by the mass-loading profile of 

Zn (fig. 11). Two ways to account for the loading of Zn 

are presented in figure 11. A spatially oriented view 

(fig. 11A), includes details of the dissolved, collodial, 

and total sampled instream loads (eq. 2), the cumulative instream load (eq. 3), and the inflow load (eq. 4). A 

comparative view (fig. 11B) for each segment allows a 

visual indication of which segments contribute the 

most to the mass load of Zn as well as which segments 

indicate a net loss of load (∆Ms <0). The loads are

Table 4. Results of chemical analyses of trace constituents in synoptic and quality-assurance samples, Silver Creek, Utah—Continued

Sample 

identification Treatment Aluminum (μg/L)

Arsenic

(μg /L)

Barium

(μg /L)

Cadmium 

(μg /L)

Chromium 

(μg /L)

Cobalt 

(μg /L)

Copper 

(μg /L)

Iron

(μg /L)

Lead 

(μg /L)

SCS-6000B FA 42.1 10.3 46.1 4.69 .20 .32 4.16 19.0 3.28

SCS-6000B RA 44.0 12.9 49.9 5.28 .15 .32 7.18 104 26.8

SCS-7000 FA 104.4 6.40 72.8 .60 .14 .11 2.61 47.8 2.09

SCS-7000 RA 601.0 8.26 94.9 1.45 .58 .26 5.01 452 29.7

SCF1-BLNK FA 34.4 .06 .10 .09 .01 .01 .25 1.19 .05

SCF1-BLNK RA 28.9 .03 .10 .09 .06 .01 .25 11.5 .27

SCF2-BLNK FA 24.3 .08 .13 .09 .01 .01 .25 1.60 .06

SCF2-BLNK RA 24.6 .03 .10 .09 .04 .01 .25 38.4 .08

SCL-BLNK FA

SCT-BLNK RA 4 .03 .10 .09 .01 .01 .25 1.00 .03
Quantification of Metal Loading 21

divided between the sampled inflow load (∆Mi, eq. 4) 

and the unsampled inflow (eq. 5). The load of Zn was 

dominated by the discharge from the Silver Creek 

tailings pipe (segment S6) and the ground-water 

inflows upstream and downstream from the wastewater treatment plant (segments S26 and S27). Other 

substantial loading included sources upstream from the 

study reach (accounted for by segment S1), loading 

near the largest beaver pond (segment S13), and 

loading downstream from the injection reach at 

Richardson Flat (segment S25). This pattern also was 

typical of Cd (tables 8 and 9).

The second pattern was typical of SO4, Mn, Na, 

and Sr (table 8); the pattern is illustrated by the massloading profile of SO4 (fig. 12). For these constituents, 

substantial loading occurred from upstream sources 

(segment S1) and the Silver Creek tailings discharge 

pipe (segment S6). This pattern differs because of the 

large contributions to load from sources upstream from 

Richardson Flat (segment S24) and from Richardson 

Flat (segment S25). The third pattern was typical of Al, 

Cl, Cu, Fe, and Pb (table 8). The mass-loading pattern 

for Fe illustrates the third pattern (fig. 13). The unique 

characteristic of this pattern is the large increase in load 

in the last stream segment, S27. 

Principal Locations of Mass Loading

These three patterns of mass-loading indicate 

eight principal sources of constituent loading: 

1. Upstream from Silver Maple Claims area—

includes segments S1 through S5 (table 6): This 

was most important for Na and Cl, which is an 

indication of the salt used on the roads. All the 

other constituents had measurable loads from 

upstream sources.

2. Silver Creek tailings discharge pipe—includes 

segment S6 (table 6): Every constituent had a 

measurable loading from the pipe discharge, but 

this was the major source of mass loading for Cd 

and Zn. It also was important for Cl, Mn, Na, Ni, 

and SO4. 

3. Remainder of Silver Maple Claims area—includes 

segments S7 through S18 (table 6): Measurable 

mass loading occurred for Al, Fe, Pb, Mn, Na, Ni, 

Zn, SO4, and Cl. The mass loading was relatively 

small compared to other locations, however, and 

most loading occurred in segment S13.

4. Downstream from Silver Maple Claims area and 

upstream from Richardson Flat—includes 

segments S19 through S24 (table 6): Mass loading 

of Cd, Cu, and Pb was important in the segments 

S20 and S22. The greatest mass loading of Sr and 

SO4 occurred in segment S24, which is upstream 

from Richardson Flat (5,000 m). This is the 

location of the “flood-plains” tailings along the 

left bank of the stream.

5. Richardson Flat—includes segment S25 (table 6): 

There was substantial mass loading for many 

constituents in the segment that brackets 

Richardson Flat (table 6). It was the second 

greatest mass loading for Al, Cu, Fe, Pb, Sr, and 

SO4, and the third greatest for Ni and Zn. All the 

constituents in table 6 had a measurable mass 

loading in this segment.

Table 4. Results of chemical analyses for trace constituents in synoptic and quality-assurance samples, Silver Creek, Utah—Continue

Sample 

identification Treatment Lithium

(μg /L)

Manganese 

(μg/L)

Molybdenum

(μg /L)

Nickel

(μg /L)

Silver 

(μg /L)

Strontium

(μg /L)

Vanadium

(μg /L)

Zinc

(μg /L)

SCS-6000B FA 12.9 220 5.08 2.40 .08 798 .66 1,616

SCS-6000B RA 14.4 217 4.98 2.40 .18 693 .72 1,784

SCS-7000 FA 6.72 61.9 1.18 .91 .08 302 1.70 243

SCS-7000 RA 8.94 74.3 1.21 1.37 .14 290 2.47 328

SCF1-BLNK FA .70 8.00 .02 .49 .08 .46 .02 2.00

SCF1-BLNK RA .70 8.00 .02 .49 .08 .46 .01 2.00

SCF2-BLNK FA .70 8.00 .02 .49 .08 .76 .01 2.00

SCF2-BLNK RA .70 8.00 .02 .49 .08 .60 .01 2.00

SCL-BLNK FA 

SCT-BLNK RA .70 8.00 .02 .49 .08 .46 .01 2.00
22 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

6. Ground-water inflows upstream from waste-water 

treatment plant—includes segment S26 (table 6). 

The flow in the stream at this point is from 

discharge of ground water to the channel of Silver 

Creek, downstream from the diversion for 

irrigation (fig. 1). The load of Zn was almost as 

great here as it was from the Silver Creek tailings 

discharge pipe. The occurrence of substantial Mn 

loading indicates the influence of tailings, where 

Mn likely occurs in the residue gangue minerals.

7. Waste-water treatment plant / ground-water 

inflow—includes segment S27 (table 6). This 

segment had the greatest load for Na and SO4, and 

second greatest load for Cl. Several metals had 

substantial loading, including Cu, Pb, Mn, Ni, and 

Zn. There were two substantial inflows in this 

stream segment, however, and neither was 

sampled so that it is not possible to say which one 

could be responsible for the large loadings that 

were measured. In figures 11 to 15, this load is 

evenly divided between surface-water and 

unsampled inflow.

Table 5. Average accuracy, precision of chemical analyses, and detection limits for synoptic samples, Silver Creek, Utah

[Minimum, percent variation from standard closest to zero; Maximum, percent variation from standard farthest from zero; Median, constituent value of 

median percent variation; Coefficient and Exponent, terms for precision equation of an exponential equation to calculate precision in percent]

Constituent Minimum

percent

Maximum

percent

Median

percent Coefficient Exponent

Detection 

limit

(micrograms per 

liter)

Calcium -2.3 58.3 7.9 88

Magnesium -.4 9.3 2.3 29

Sodium 4.6 -13.0 9.2 4.8248 .0067 67

Potassium -1.9 11.0 5.3 15

Sulfate -.77 -1.40 1.09 11.279 -.5244 .57

Chloride .43 .46 .45 .9821 .1175 .15

Bromide1 5.2 5.4 5.3 .2985 4.3189 .15

Silica .5 -50.6 5.6 48

Aluminum -2.0 50.3 5.2 14.114 -.104 4

Arsenic -2.3 -57.5 13.1 .03

Barium 2.5 15.6 6.2 .1

Cadmium 2.9 52.2 4.5 9.3566 -.1178 .02

Cadmium .9 20.1 3.9 .02

Chromium -3.0 25.5 4.5 .01

Cobalt .0 17.1 4.5 .01

Copper -.5 17.7 3.5 7.4538 -.0153 .25

Iron -2.0 6.0 3.4 1.8432 .0664 1

Lead -2.5 20.9 5.4 4.3394 .0481 .03

Lithium .6 20.9 4.7 .7

Manganese .0 7.5 3.2 4.7533 -.0312 8

Molybdenum -.4 33.7 4.0 .02

Molybdenum -1.3 14.6 4.0 .02

Nickel 2.0 -56.6 7.4 16.396 -.1946 .49

Silver -.4 -473.7 32.4 .01

Strontium .1 16.3 4.2 5.1452 .0216 .46

Vanadium -2.5 -54.8 9.2 .01

Zinc -.5 7.2 3.9 4.1745 -.0127 2

1Bromide equation is linear with the slope and intercept given as coefficient and exponent.
Quantification of Metal Loading 23

 

Figure 4. Variation of bromide concentration and calculated discharge with distance, Silver Creek, Utah.

0 200 400 600 800 1,000 1,200 1,400

0

1

2

3

4

5

End of Silver Maple claims area

T3 site - below large pond

Weir at end of Prospector pond

(Start of Silver Maple Claims area)

Bromide, main channel

Discharge

Bromide, off main channel

 Bromide, inflow

DISTANCE ALONG INJECTION REACH, IN METERS

BROMIDE CONCENTRATION, IN MILLIGRAMS PER LITER

Upper end of Prospector pond

30

40

50

60

70

80

90

100

DISCHARGE, IN LITERS PER SECOND
24 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

8. Downstream from waste-water treatment plant to 

Wanship—includes segment S28 (table 6). This 

long section of Silver Creek, which was accounted 

for at the town of Wanship, contributed the greatest 

mass load for many of the constituents (table 6, 

segment S28; recall that the values of distance for 

the last five sites in table 6 are arbitrary). Details of 

mass loading along segment S28 are not known 

because there was no detailed evaluation 

downstream from the site at 6,500 m. The large 

increases in loads for Al, Cu, Fe, and Pb mostly 

were increases in the colloidal phase. Note, 

however, that the greater loads do not necessarily 

mean greater concentrations; the concentration of 

Zn, for example, is near the toxicity standards at 

7,000 m (fig. 8). 

A comparison of mass loading for Cd, Cu, Pb, 

and Zn is presented in figure 14. For Cd, the greatest 

mass loading was in the area of segments S19 through 

S24. This area also contributed the second greatest 

mass of SO4 (table 6). Large deposits of tailings material occur along the stream in this area. The principal 

area of loading for Cu (fig. 14B) and Pb (fig. 14C) was 

the Wanship segment (S28). This pattern was the same 

for Al and Fe (table 6) and reflects a colloidal load in 

the sample from Wanship (sample at 7,000 m in fig. 7). 

Metal sources in this part of the study reach were not 

investigated. There also were several upstream sources, 

however, particularly Richardson Flat (segment S25).

Table 6. Median concentration of selected constituents, grouped by chemical similarity among synoptic samples, Silver Creek, Utah

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

Constituent Unit Phase

Group 1

Upstream from 

Silver Maple Claims 

area

Group 2

Downstream from 

Silver Creek tailings 

discharge

Group 3

Downstream from 

large beaver pond

Utah Department 

of Environmental 

Quality samples

Number of samples

4 8 14 6

pH Standard units Dissolved 8.89 7.82 7.75 8.07

Calcium mg/L Dissolved 106 125 130 121

Magnesium mg/L Dissolved 24.2 26.1 27.9 34.7

Sodium mg/L Dissolved 157 143 160 93.1

Alkalinity, as CaCO3 mg/L Dissolved 105 98.3 110 140

Sulfate mg/L Dissolved 157 228 234 267

Chloride mg/L Dissolved 349 374 411 264

Fluoride mg/L Dissolved .94 1.10 1.33 .94

Aluminum μg/L Dissolved 33.5 29.0 29.5 39.1

μg/L Colloidal 393 127 86.2 75.1

Arsenic μg/L Dissolved 2.99 2.43 2.93 4.69

μg/L Colloidal 1.77 1.34 2.16 2.46

Cadmium μg/L Dissolved 3.54 5.03 2.03 3.94

μg/L Colloidal 3.85 3.27 2.51 .99

Copper μg/L Dissolved 2.98 1.60 1.15 2.71

μg/L Colloidal 3.77 1.97 2.14 2.19

Iron μg/L Dissolved 4.94 6.26 11.6 16.7

μg/L Colloidal 467 217 272 267

Lead μg/L Dissolved .69 .86 .74 1.97

μg/L Colloidal 13.6 9.62 17.4 24.7

Manganese μg/L Dissolved 121 167 261 129

μg/L Colloidal 44.8 15.3 17.3 20.9

Nickel μg/L Dissolved 1.37 2.96 3.58 2.04

μg/L Colloidal .63 1.01 .58 .49

Strontium μg/L Dissolved 446 476 507 787

μg/L Colloidal 13.5 .46 .46 .46

Zinc μg/L Dissolved 342 1,314 1,636 840

μg/L Colloidal 500 153 214 110
Quantification of Metal Loading 25

 

Figure 5. Variation of (A) pH and (B) sulfate concentration with distance, Silver Creek, Utah.

0 250 500 750 1,000 1,250 5,000 6,000 7,000

0

50

100

150

200

250

600

700

800

900

0 250 500 750 1,000 1,250 5,000 6,000 7,000

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

Stream group 1

Stream group 2

Stream group 3

Department of Environmental

 Quality samples

Inflow

Downstream from

Prospector tailings

pipe

End of injection reach

End of Silver Maple Claims area

Start of Silver Maple Claims area

Beginning of injection reach

SULFATE CONCENTRATION,

IN MILLIGRAMS PER LITER

DISTANCE ALONG STUDY REACH, IN METERS End of largest beaver pond

Stream group 1

Stream group 2

Stream group 3

Department of Environmental

 Quality samples

Inflow

Downstream from

Prospector tailings

pipe

End of largest

beaver pond

End of injection reach

End of Silver Maple Claims area

Start of Silver Maple Claims area

B

pH, IN STANDARD UNITS

DISTANCE ALONG STUDY REACH, IN METERS

A

Beginning of injection reach
26 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

 

Figure 6. Distribution of dissolved and colloidal concentration of metals in synoptic stream samples, Silver Creek, Utah.

AlD

ALC

ASDASC

CDDCDCCUDCUC

FED

FEC

PBDPBC

MND

MNC

NID

NIC

SRDSRC

ZNDZNC

0.01

0.1

1

10

100

1,000

10,000

 CONSTITUENT

CONCENTRATION, IN MICROGRAMS PER LITER

Al - aluminum

As - arsenic

Cd - cadmium

Cu - copper

Fe - iron

Pb - lead

Mn - manganese

Ni - nickel

Sr - strontium

Zn - zinc

D - Dissolved concentration

C - Colloidal concentration
Quantification of Metal Loading 27

 

Figure 7. Variation of dissolved and colloidal aluminum concentration with distance for Silver Creek, Utah.

0 250 500 750 1,000 1,250 1,500 5,000 6,000 7,000

0

100

200

300

400

500

2,500

3,000

End of Silver Maple

Claims area

End of injection reach

Downstream from Prospector pipe

Start of Silver Maple

Claims area

ALUMINUM CONCENRATION, IN MICROGRAMS PER LITER

DISTANCE ALONG STUDY REACH, IN METERS

Total-recoverable

Stream group 1, dissolved

Stream group 1, colloidal

Stream group 2, dissoved

Stream group 2, colloidal

Stream group 3, dissolved

Stream group 3, colloidal

Department of Environmental

 Quality sample, dissolved

Department of Environmental

 Quality sample, colloidal

Inflow

Start of injection reach
28 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

 

Figure 8. Variation of dissolved and colloidal zinc concentration with distance for Silver Creek, Utah.

0 250 500 750 1,000 1,250 1,500 5,000 6,000 7,000

0

500

1,000

1,500

2,000

4,000

6,000

8,000

10,000

Downstream from largest beaver pond

End of Silver Maple

Claims area

End of injection reach

Downstream from Prospector pipe

Start of Silver Maple

Claims area

ZINC CONCENRATION, IN MICROGRAMS PER LITER

DISTANCE ALONG STUDY REACH, IN METERS

Total-recoverable

Acute toxicity

Chronic toxicity

Stream group 1, dissolved

Stream group 1, colloidal

Stream group 2, dissoved

Stream group 2, colloidal

Stream group 3, dissolved

Stream group 3, colloidal

Department of Environmental

 Quality sample, dissolved

Department of Environmental

 Quality sample, colloidal

Inflow

Start of injection reach
Quantification of Metal Loading 29

 

Figure 9. Variation of dissolved (A) sodium and (B) chloride concentration with distance for Silver Creek, Utah.

0 500 1,000 1,500 5,000 6,000 7,000

0

100

200

300

400

500

600

700

800

Start of Silver Maple

Claims area

End of Silver Maple

Claims area

DISTANCE ALONG STUDY REACH, IN METERS

Main channel

Stream group 1, dissolved

Stream group 2, dissolved

Stream group 3, dissolved

Department of Environmental

 Quality sample, dissolved

Inflow

Downstream from 

largest beaver pond

End of injection reach

Downstream from 

Prospector pipe

CHLORIDE CONCENTRATION, 

IN MILLIGRAMS PER LITER

DISTANCE ALONG STUDY REACH, IN METERS

Start of injection reach

B

A

0 500 1,000 1,500 5,000 6,000 7,000

0

100

200

300

400

500

Main channel

Stream group 1, dissolved

Stream group 2, dissolved

Stream group 3, dissolved

Department of Environmental

 Quality sample, dissolved

Inflow

Start of injection reach

Start of Silver Maple

Claims area

Downstream from 

Prospector pipe

Downstream from 

largest beaver pond

End of Silver Maple

Claims area

SODIUM CONCENTRATION,

End of injection reach

IN MILLIGRAMS PER LITER
30 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

The greatest loading for Zn (fig. 14D) was from 

the Silver Creek tailings discharge pipe (segment S6). 

The load from the remainder of the Silver Maple 

Claims area (segments S7 through S18), however, was 

nearly as great, comparing the instream loads. The Zn 

load contributed by ground-water inflows upstream 

from the waste-water treatment plant (segment S26) 

was almost as large as the load from segment S6. 

Because the loads from these locations are comparable, 

it is possible that remediation efforts focused only on 

one location might not decrease Zn concentrations in 

Silver Creek to levels below the aquatic toxicity standards. 

For each of these elements, the inflow load measured for the Silver Creek tailings discharge pile (segment S6) was greater than that for the instream load. 

The difference was relatively small, only 4 percent, for 

Cd (fig. 14A) and 20 percent for Zn (fig. 14D). The difference was 70 percent for Cu (fig. 14B) and 83 percent 

for Pb (fig. 14C). The mass load that is implied by 

these percentages is consistent with a greater affinity of 

Cu and Pb to associate with the solid phase and be 

removed from solution. There likely was substantial Fe 

collodial material because almost all of the inflow load 

of Fe was removed (fig. 13A).

Unsampled Inflow

Unsampled inflow was greater than 50 percent 

for all the constituents except Zn (summary calculations in table 9). Much of this unsampled inflow 

occurred in the Silver Maple Claims area, downstream 

from the Silver Creek tailings discharge pipe, and

 

Figure 10. Pond receiving discharge from the Silver Creek tailings discharge pipe, near Park City, Utah.

Discharge

point of

Silver Creek tailings

drainage

pipe (370 meters)

Start of

Silver Maple

Claims area,

 T2 site at

360 meters

Outflow of pond

receiving pipe

discharge (398 meters)
Quantification of Metal Loading 31

 

between the Silver Maple Claims area and Richardson 

Flat (table 6), as indicated in the mass-loading profiles 

for Zn (fig. 11B), SO4 (fig. 12B), and Fe (fig. 13B). 

Tailings that are visible between 398 m and 1,420 m 

are a plausible source for these loads, but the 

unsampled inflow likely indicates ground-water 

discharge in this location where the alluvium is 

somewhat constricted by bedrock.

Unsampled inflow for Na and Cl occurred in segment S6, which included the Silver Creek tailings discharge pipe (fig. 15). This likely indicates inflow of 

water that has been affected by road salt, because the 

pipe discharge accounted for all the load of tailingsrelated constituents, but not all the Cl load (fig. 15B). 

Loads of Ca, Mg, and Sr also occurred partly as unsampled inflow for segment S6, which is consistent with 

the likely composition of the other 70 percent of the 

discharge in this stream segment. These same constituents are important in the unsampled inflow for segment 

S13. That segment also had unsampled inflow of Zn 

and other metals, so it was likely affected by interaction 

with tailings in the Silver Maple Claims area.

The two main locations of unsampled inflow 

were downstream from the injection study reach at 

Richardson Flat and upstream from the town of Wanship (segment S25, fig. 13B and segment S38, fig. 

15B). Loads in these segments were called unsampled 

inflow only because there were no inflow samples collected. Further work may indicate what the sources are 

for this mass loading.

Attenuation

Attenuation for many constituents occurred in 

three principal locations.

1. Between Park City and the injection study reach 

(segment S2) —All constituents, except Cu, lost 

mass in this segment. The cause of the mass loss is 

not known; the stream between 0 m and the 

injection reach at 72 m was not investigated as part 

of this study. Because most every constituent lost 

mass, the loss could result from a diversion of 

water, and thus mass. This is consistent with the 

decrease in discharge from 72 to 42 L/s (table 1). 

2. Downstream from the Silver Creek tailings 

discharge pipe (segment S7)—Measurable 

attenuation occurred for all the constituents except 

SO4 in this segment (table 8). It is very likely, 

however, that attenuation of all the constituents 

that were added from the Silver Creek tailings 

discharge pipe, accounted for in segment S6, was 

substantial in the pond area. Evidence for this 

attenuation is in the difference between large 

inflow loads and the smaller instream loads (see 

fig. 14). Because the increased flow in segment S6, 

calculated from the Br tracer, was comparable to a 

flow-meter measurement, and the sampled Zn 

concentration in the discharge pipe was high, there 

is no reason to think there is an error in this inflow 

load calculation. The same difference was 

indicated for SO4 (fig. 12) and Fe (fig. 13).

3. Downstream from Silver Maple Claims area 

(segments S18 through S21)—Loads of As, Cd, 

Cu, Fe, Pb, and Mn all were attenuated 

substantially in these stream segments. A cause for 

the attenuation is not known because this location, 

downstream from the Silver Maple Claims study 

reach, was not studied in detail.

Table 7. Calculated concentration of selected constituents in 

water from Silver Creek tailings discharge pipe, Silver Creek, 

Utah

Constituent Measured 

value Adjusted value

Dissolved (milligrams per liter)

Calcium 288 440

Magnesium 40.1 59.5

Sodium 118 156

Sulfate 652 1,020

Chloride 312 433

Total recoverable (micrograms per liter)

Aluminum 2,470 2,910

Arsenic 76 90.6

Cadmium 43.6 51.2

Copper 29.2 34.1

Iron 8,860 10,600

Lead 182 216

Manganese 1,010 1,180

Nickel 19.4 22.9

Strontium 556 630

Zinc 8,560 10,100
32 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

Table 8. Change in load for individual stream segments, Silver Creek, Utah

[Segment, stream segment; Distance, distance at the end of the segment; Na, sodium; SO4, sulfate; Cl, chloride; Al, aluminum; Cd, cadmium; Cu, copper; Fe, 

iron; Pb, lead; Mn, manganese; Ni, nickel; Sr, strontium; Zn, zinc; all values reported in kilograms per day, except percents; blank cells indicate change in load 

is less than the calculated error; Italicized bold numbers in parentheses indicate rank for the five greatest loads]

Segment Distance, 

in meters Na SO4 Cl Al Cd Cu Fe Pb Mn Ni Sr Zn

S1 0 (2)1,070 840 (3)2,270 (3)1.88 (2)0.055 (5)0.028 (3)2.13 0.093 (4)1.05 (4)0.013 2.58 (4)6.45

S2 72 -456 -412 -890 -.322 -.030 -.003 -.379 -.041 -.423 -.006 -.908 -3.73

S3 225 -49.8 103 -213 .003 -.042 .001 .495

S4 265 -80.9 -64.3 -141 .005

S5 360 106 81.3 192 -.478 -.004 -.006 -.548 -.006

S6 398 (3)422 (5)926 (4)1,020 (4).949 (1).064 .019 (5)1.22 .061 (5)1.03 (2).025 1.78 (1)10.2

S7 498 215 90.5 442 -.978 -.019 -.010 -.916 -.040 -.308 -.008 -3.23

S8 544 -146 -158 -263 .243 .009 -.001 .121 .027 .017 -.001 .133 1.80

S9 576 192 209 304 -.670 -.014 -.167 -.027 .105 .004 -.856

S10 637 -236 -218 -454 -.004 .348 .700

S11 684 -.089 -.006 -.274 -.006 -.329 -1.31

S12 710 .137 -.006 -.143 .027 -.268 -.291 -1.13

S13 778 300 250 534 .145 .009 .008 .728 .046 1.02 .471 (5)5.99

S14 832 -122 -140 .095 -.019 -.006 .281 .034 .264 -.007

S15 877 263 259 435 -.378 -.011 -.007 -.699 -.084 -.205 .008 -.959

S16 940 (5).818 .004 .017 (4)1.27 (5).135 .327

S17 992 -.461 -.009 -.339 -.052

S18 1,017 -172 -190 -311 .356 .007 .013 .653 .055 .224 .008 .663

S19 1,081 -.481 -.010 -.014 -1.05 -.093 -.372 -1.09

S20 1,212 (3).040 -.048

S21 1,344 109 143 214 -.234 -.037 -.449 .059 -1.05

S22 1,380 -127 -134 -242 .120 .019 (4).040 .670 (4).145 1.23

S23 1,420 244 704 .244 -.008 -.008 .304 .028 .201 .351

S24 5,000 -224 (2)1,650 -455 -.194 .016 .675 .075 -.297 -.006 (1)6.67 -3.52

S25 5,500 (5)384 (3)1,490 (5)967 (2)2.26 .010 (2).062 (2)3.03 (2).445 .734 (5).010 (2)6.08 4.33

S26 6,000 246 (4)1,150 830 .100 (4).035 .018 .547 .026 (2)1.12 .010 (5)2.95 (2)9.69

S27 6,500 (1)1,220 (1)2,220 (2)2,840 .345 (5).019 (3).055 .504 (3).245 (3)1.11 (3).015 (4)5.11 (3)8.35

S28 7,000 (4)397 (1)4,770 (1)27.2 .013 (1).158 (1)19.7 (1)1.09 (1)1.19 (1).039 (3)5.83 -2.94

Table 9. Summary of load calculations for selected constituents, Silver Creek, Utah

[Na, sodium; SO4, sulfate; Cl, chloride; Al, aluminum; Cd, cadmium; Cu, copper; Fe, iron; Pb, lead; Mn, manganese; Ni, nickel; Sr, strontium; Zn, zinc; all 

values reported in kilograms per day, except percents]

Na SO4 Cl Al Cd Cu Fe Pb Mn Ni Sr Zn

Cumulative instream 

load

5,160 9,410 15,500 34.9 0.301 0.417 32.2 2.20 8.06 0.131 32.6 49.2

Cumulative inflow 

load

2,460 4,170 5,590 5.4 .130 .121 14.3 .576 3.46 .052 8.39 25.9

Percent inflow load 47.6 44 36.0 15.5 43.1 29.0 44 26.2 42.9 40.1 25.7 53

Unsampled inflow 2,710 5,240 9,930 29.5 .171 .3 17.9 1.6 4.60 .078 24.2 23.27

Percent unsampled 52.4 56 64.0 84.5 56.9 71.0 55.7 73.8 57.1 59.9 74.3 47.3

Attenuation 1,610 1,180 2,970 4.29 .164 .1 5.0 .0 1.92 .028 1.20 19.8

Percent attenuation 31.2 13 19.1 12.3 54.5 16.3 15.4 .0 23.8 21.3 3.7 40.3
Quantification of Metal Loading 33

Figure 11. Variation of (A) zinc load with distance and (B) change in load for individual stream segments, Silver Creek, Utah. S01 S02 S03 S04 S05 S06 S07 S08 S09 S10 S11 S12 S13 S14 S15 S16 S17 S18 S19 S20 S21 S22 S23 S24

S25S26S27S28

-5

0

5

10

15

0 250 500 750 1,000 1,250 1,500 5,000 6,000 7,000

0

10

20

30

40

50

B

CHANGE IN LOAD, IN KILOGRAMS PER DAY

STREAM SEGMENT

 Sampled inflow

 Unsampled inflow

 Loss

 DISTANCE ALONG STUDY REACH, IN METERS

Downstream from waste-water

treatment plant (S27)

Upstream from waste-water

treatment plant (S26)

Downstream from

Richardson Flat

(S25)

End of injection reach (S23)

Downstream from

Silver Creek tailings

pipe (S06)

Start of Silver

Maple Claims area (S05)

 Dissolved load

 Colloidal load

 Total load

 Cumulative instream load

 Cumulative inflow load

Start of injection reach (S02)

Downstream from

largest beaver pond

(S13)

A

End of Silver Maple

Claims area (S18)

ZINC LOAD, IN KILOGRAMS PER DAY
34 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

Figure 12. Variation of (A) sulfate load with distance and (B) change in load for individual stream segments, Silver Creek, Utah. S01 S02 S03 S04 S05 S06 S07 S08 S09 S10 S11 S12 S13 S14 S15 S16 S17 S18 S19 S20 S21 S22 S23 S24

S25S26S27S28

-500

0

500

1,000

1,500

2,000

2,500

0 250 500 750 1,000 1,250 1,500 5,000 6,000 7,000

0

2,000

4,000

6,000

8,000

10,000

B

CHANGE IN LOAD, IN KILOGRAMS PER DAY

STREAM SEGMENT

 Sampled inflow

 Unsampled inflow

 Loss

 DISTANCE ALONG STUDY REACH, IN METERS

Downstream from waste-water

treatment plant (S27)

Upstream from waste-water

treatment plant (S26)

Downstream from

Richardson Flat

(S25)

End of injection reach (S23)

Downstream from

Silver Creek tailings

pipe (S06)

Start of Silver

Maple Claims area (S05)

 Dissolved load

 Cumulative instream load

 Cumulative inflow load

Start of injection reach (S02)

Downstream from

largest beaver pond

(S13)

A

End of Silver Maple

Claims area (S18)

SULFATE LOAD, IN KILOGRAMS PER DAY
Quantification of Metal Loading 35

Figure 13. Variation of (A) iron load with distance and (B) change in load for individual stream segments, Silver Creek, Utah. S01 S02 S03 S04 S05 S06 S07 S08 S09 S10 S11 S12 S13 S14 S15 S16 S17 S18 S19 S20 S21 S22 S23 S24

S25S26S27S28

-2

0

2

4

6

8

10

12

14

16

18

20

0 250 500 750 1,000 1,250 1,500 5,000 6,000 7,000

0

5

10

15

20

25

30

35

B

CHANGE IN LOAD, IN KILOGRAMS PER DAY

STREAM SEGMENT

 Sampled inflow

 Unsampled inflow

 Loss

 DISTANCE ALONG STUDY REACH, IN METERS

Downstream from waste-water

treatment plant (S27)

Upstream from waste-water

treatment plant (S26)

Downstream from

Richardson Flat

(S25)

End of injection reach (S23)

Downstream from

Silver Creek tailings

pipe (S06)

Start of Silver

Maple Claims area (S05)

 Dissolved load

 Colloidal load

 Total load

 Cumulative instream load

 Cumulative inflow load

Start of injection reach (S02)

Downstream from

largest beaver pond

(S13)

A

End of Silver Maple

Claims area (S18)

IRON LOAD, IN KILOGRAMS PER DAY
36 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

Figure 14. Load for (A) cadmium, (B) copper, (C) lead, and (D) zinc for principal locations, Silver Creek, Utah.

Upstream from injection

Tailings discharge pipe

Remainder of Silver Maple

Downstream from Silver Maple

Richardson Flat

Ground-water discharge

WWTP - Ground-water inflow

Upstream from Wanship

0

2

4

6

8

10

12

 Instream load

 Inflow load

MASS LOAD, IN KILOGRAMS PER DAY

0.0

0.2

0.4

0.6

0.8

1.0

 Instream load

 Inflow load

0.00

0.05

0.10

0.15

0.20

 Instream load

 Inflow load

0.00

0.02

0.04

0.06

0.08

0.10

 Instream load

 Inflow load

D

C

B

A
Quantification of Metal Loading 37

Figure 15. Variation of (A) chloride load with distance and (B) change in load for individual stream segments, Silver Creek, Utah.. S01 S02 S03 S04 S05 S06 S07 S08 S09 S10 S11 S12 S13 S14 S15 S16 S17 S18 S19 S20 S21 S22 S23 S24 S25

S26S27S28

-1,000

0

1,000

2,000

3,000

4,000

5,000

0 250 500 750 1,000 1,250 1,500 5,000 6,000 7,000

0

4,000

8,000

12,000

16,000

B

CHANGE IN LOAD, IN KILOGRAMS PER DAY

STREAM SEGMENT

 Sampled inflow

 Unsampled inflow

 Loss

 DISTANCE ALONG STUDY REACH, IN METERS

Downstream from waste-water

treatment plant (S27)

Upstream from waste-water

treatment plant (S26)

Downstream from

Richardson Flat

(S25)

End of injection reach (S23)

Downstream from

Silver Creek tailings

pipe (S06)

Start of Silver

Maple Claims area (S05)

 Dissolved load

 Cumulative instream load

 Cumulative inflow load

Start of injection reach (S02)

Downstream from

largest beaver pond

(S13)

A

End of Silver Maple

Claims area (S18)

CHLORIDE LOAD, IN KILOGRAMS PER DAY
38 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah

SUMMARY

Sampling by the U.S. Geological Survey and 

other agencies, both upstream and downstream from 

the Silver Maple Claims area indicated that there was a 

substantial increase in metal loads in Silver Creek. Not 

enough data were collected, however, for the Bureau of 

Land Management, which administers the Silver Maple 

Claims area, to make science-based decisions about 

possible remediation in the area. In May 2002, the U.S. 

Geological Survey conducted a mass-loading study to 

provide the needed detail. The study included a tracer 

injection to provide values of discharge for chemical 

synoptic sampling along a 1,420-m reach of Silver 

Creek in Utah. Loads along a much longer study reach 

were calculated by area-velocity discharge measurements and by analyses of water samples collected at 

seven sites selected by the Utah Department of Environmental Quality. 

Loads of constituents varied from a few kg/day 

for most metals to several thousand kg/day for major 

ions. For example, the cumulative instream load for Zn 

was 49.2 kg/day, and that for SO4 was 9,410 kg/day. 

The study was able to divide the total loading of 

selected constituents into eight areas so that the relative 

importance of different sources is illustrated.

For example, a substantial load of Zn came from 

sources upstream from the Park City sample (segment 

S1). The greatest mass loading of Zn, however, 

occurred at the Silver Creek tailings discharge pipe, 

which drains into the Silver Maple Claims area. There 

was a substantial mass loading of Zn through the Silver 

Maple Claims area; most of this occurred where there 

was an increase in discharge about halfway through the 

area. For comparison, the instream load of Zn in the 

stream segment including the Silver Creek tailings discharge pipe was 10.2 kg/day and the cumulative 

instream load for the rest of the Silver Maple Claims 

area was 8.5 kg/day. Increases in Zn load and other 

metal loads in the vicinity of Richardson Flat also were 

substantial. Only a small increase in Zn load occurred 

downstream from the waste-water treatment plant and 

the town of Wanship, but for most constituents the 

greatest increases in load occurred in that area.

Distinction of the load contribution of the Silver 

Creek tailings discharge pipe from that of the rest of the 

Silver Maple Claims area helps to compare their relative influence on Silver Creek. Each metal load 

increased downstream from the Silver Creek tailings 

discharge pipe. These increases were greater than the 

increases of mass load through the rest of the Silver 

Maple Claims area, except for Cu load. The Cu load 

from the pipe was 0.019 kg/day and from the rest of the 

Silver Maple Claims area was 0.038 kg/day. Understanding these relative contributions of load in the 

Silver Maple Claims area and along the larger study 

reach will help water and land managers make sciencebased decisions about remediation efforts.

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40 Quality and Sources of Shallow Ground Water in Areas of Recent Residential Development in Salt Lake Valley, Salt Lake County, Utah