U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report

Fraser River Watershed, Colorado—

Assessment of Available Water-Quantity and

Water-Quality Data Through Water Year 1997

By Lori E. Apodaca and Jeffrey B. Bails

Denver, Colorado

1999

98–4255

Prepared in cooperation with

GRAND COUNTY and the

COLORADO DEPARTMENT OF PUBLIC HEALTH

AND ENVIRONMENT
U.S. DEPARTMENT OF THE INTERIOR

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

The use of firm, trade, and brand names in this report is for identification purposes only and does

not constitute endorsement by the U.S. Geological Survey.

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

U.S. Geological Survey

Information Services

Box 25286

Federal Center

Denver, CO 80225

from:

District Chief

U.S. Geological Survey

Box 25046, Mail Stop 415

Denver Federal Center

Denver, CO 80225-0046
CONTENTS III

CONTENTS

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

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

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

Acknowledgments ....................................................................................................................................................... 4

Description of Study Area ..................................................................................................................................................... 4

Data Sources and Compilation .............................................................................................................................................. 4

Methods of Data Review and Analysis.................................................................................................................................. 10

Ground Water......................................................................................................................................................................... 20

Water Quantity............................................................................................................................................................. 20

Water Quality............................................................................................................................................................... 20

Occurrence of Inorganic Compounds ................................................................................................................ 22

Occurrence of Organic Compounds .................................................................................................................. 25

Dating Analysis ........................................................................................................................................................... 28

Surface Water......................................................................................................................................................................... 28

Water Quantity............................................................................................................................................................. 28

Water Quality............................................................................................................................................................... 31

Spatial Distribution of Concentrations .............................................................................................................. 38

Temporal Trends in Nutrient Species Concentrations ....................................................................................... 38

Summary................................................................................................................................................................................ 46

References Cited.................................................................................................................................................................... 48

Appendix I—List of properties and constituents for ground-water-quality data in the Fraser River watershed................... 51

FIGURES

1–6. Maps showing:

1. Location of the Fraser River watershed, Grand County, Colorado.................................................................. 3

2. Average annual precipitation (1951–80) in the Fraser River watershed.......................................................... 5

3. Geology of the Fraser River watershed ........................................................................................................... 6

4. Land use/land cover for the Fraser River watershed, 1990.............................................................................. 8

5. Location of the U.S. Geological Survey (USGS) National Water Information System (NWIS)

ground-water-quality and surface-water-quantity and water-quality sites in the Fraser River

watershed ......................................................................................................................................................... 11

6. Location of the U.S. Environmental Protection Agency (USEPA) Storage and Retrieval (STORET)

surface-water-quality sites in the Fraser River watershed ............................................................................... 12

7. Graph showing distribution of sampling dates and period of record for the National Water

Information System (NWIS) and the Storage and Retrieval (STORET) surface-water sites for nutrient data

collected in the Fraser River watershed .................................................................................................................... 18

8. Map showing generalized water-table map for the alluvial and Troublesome Formation

aquifers upstream from Tabernash in the Fraser River watershed (1960–96) .......................................................... 21

9–11. Graphs showing:

9. Distribution of specific conductance, sulfate, iron, and manganese for spring and fall sampling

and by land-use/land-cover classifications for Upper Colorado River Basin (UCOL) NAWQA

ground-water sites............................................................................................................................................ 26

10. Annual mean streamflow at selected surface-water stations in the Fraser River watershed............................ 32

11. Mean monthly streamflow at selected surface-water stations in the Fraser River watershed.......................... 33

12–13. Boxplots showing:

12. Distribution of pH, specific conductance, chloride, and manganese by land-use/land-cover classifications

for all surface-water sites................................................................................................................................. 36

13. Distribution of ammonia, nitrite, nitrate, orthophosphate, and total phosphorus by land-use/land-cover

classifications for all surface-water sites ......................................................................................................... 37
IV CONTENTS

14–18. Maps showing:

14. Spatial distribution of median concentrations for specific conductance ......................................................... 39

15. Spatial distribution of median concentrations for ammonia............................................................................ 40

16. Spatial distribution of median concentrations for nitrite................................................................................. 41

17. Spatial distribution of median concentrations for nitrate ................................................................................ 42

18. Spatial distribution of median concentrations for total phosphorus................................................................ 43

19. Graph showing temporal variations in ammonia and total phosphorus concentrations for selected sites in the

Fraser River watershed ............................................................................................................................................. 44

TABLES

1. Sources of water-related data for the Fraser River watershed................................................................................. 9

2. Characteristics of ground-water-quality sites from the U.S. Geological Survey (USGS) National

Water Information System (NWIS) data base in the Fraser River watershed......................................................... 13

3. Characteristics of surface-water-quality sites in the Fraser River watershed.......................................................... 14

4. Summary of the minimum, median, and maximum values for the ground-water-quality properties and

constituents for wells sampled for the Upper Colorado River Basin (UCOL) NAWQA study.............................. 23

5. Chlorofluorocarbon data and calculated apparent ground-water recharge date for six monitoring wells

sampled in the Fraser River watershed.................................................................................................................... 29

6. Generalized water budget for the Fraser River watershed ...................................................................................... 30

7. Hydrologic characteristics for selected surface-water stations in the Fraser River watershed ............................... 30

8. Summary of the minimum, median, and maximum values for the surface-water-quality properties and

constituents for all sites sampled in the Fraser River watershed............................................................................. 34

9. Results of the seasonal Kendall test for trends of selected nutrient species in the Fraser River

watershed................................................................................................................................................................. 45

Degree Fahrenheit (°F) may be converted to degree Celsius (°C) by using the following equation:

°C = 5/9 (°F–32).

Degree Celsius (°C) may be converted to degree Fahrenheit (°F) by using the following equation:

°F = 9/5 (°C) + 32.

CONVERSION FACTORS AND ABBREVIATIONS

Multiply By To obtain

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

cubic foot per second (ft3/s) 0.028 cubic meter per second

foot (ft) 0.3048 meter

gallon (gal) 3.785 liter

gallon per minute (gal/min) 0.06308 liter per second

inch 25.4 millimeter

inch per year (in/yr) 25.4 millimeter per year

mile (mi) 1.609 kilometer

picocuries per liter (pCi/L) 0.3125 tritium units

pound (lb) 0.4536 kilogram

square mile (mi2

) 2.59 square kilometer
CONTENTS V

ADDITIONAL ABBREVIATIONS OR TERMS

cols/100 mL, colonies per 100 milliliters

DOC, dissolved organic carbon

DWA, drinking water advisory

gpd/ft, gallons per day per foot

HA, health advisory

μg/L, microgram per liter

μS/cm, microsiemens per centimeter at 25 degrees Celsius

mg/L, milligram per liter

mL, milliliter

Ma, Mega-annum

MBAS, methylene blue active substances

MCL, maximum contaminant level

MCLG, maximum contaminant level goal

NTU, nephelometric turbidity units

pfu, plaque-forming unit

PMCL, proposed maximum contaminant level

SMCL, secondary maximum contaminant level

units/yr, units per year

as N, as quantified, as measured nitrogen

as P, as quantified, as measured phosphorus

VOC, volatile organic compound

Water year is the continuous 12-month period, October 1 through September 30, in U.S. Geological

Survey reports dealing with surface-water supply. The water year is designated by the year in which

it ends. Thus, the year ending September 30, 1980, is referred to as water year 1980.
Abstract 1

Fraser River Watershed, Colorado—Assessment of

Available Water-Quantity and Water-Quality Data

Through Water Year 1997

By Lori E. Apodaca and Jeffrey B. Bails

Abstract

The water-quantity and water-quality data

for the Fraser River watershed through water

year 1997 were compiled for ground-water and

surface-water sites. In order to assess the waterquality data, the data were related to land use/land

cover in the watershed. Data from 81 water-quantity and water-quality sites, which consisted of

9 ground-water sites and 72 surface-water sites,

were available for analysis. However, the data

were limited and frequently contained only one or

two water-quality analyses per site.

The Fraser River flows about 28 miles from

its headwaters at the Continental Divide to the

confluence with the Colorado River. Groundwater resources in the watershed are used for residential and municipal drinking-water supplies.

Surface water is available for use, but water diversions in the upper parts of the watershed reduce

the flow in the river. Land use/land cover in the

watershed is predominantly forested land, but

increasing urban development has the potential to

affect the quantity and quality of the water

resources.

Analysis of the limited ground-water data

in the watershed indicates that changes in the land

use/land cover affect the shallow ground-water

quality. Water-quality data from eight shallow

monitoring wells in the alluvial aquifer show that

iron and manganese concentrations exceeded the

U.S. Environmental Protection Agency secondary

maximum contaminant level. Radon concentrations from these monitoring wells exceeded the

U.S. Environmental Protection Agency proposed

maximum contaminant level. The proposed radon

contaminant level is currently being revised. The

presence of volatile organic compounds at two

monitoring wells in the watershed indicates that

land use affects the shallow ground water. In addition, bacteria detected in three samples are at

concentrations that would be a concern for public

health if the water was to be used as a drinking

supply. Methylene blue active substances were

detected in the ground water at some sites and are

a possible indication of contamination from

wastewater. Age of the alluvial ground water

ranged from 10 to 30 years; therefore, results of

land-management practices to improve water

quality may not be apparent for many years.

Surface-water-quality data for the Fraser

River watershed are sparse. The surface-waterquality data show that elevated concentrations of

selected constituents generally are related to

specific land uses in the watershed. For one

sample (about 2 percent; 1 of 53), dissolved

manganese concentration exceeded the

U.S. Environmental Protection Agency secondary

maximum contaminant level. Two samples from

two surface-water sites in the watershed exceeded

the un-ionized ammonia chronic criterion. Spatial

distribution of nutrient species (ammonia, nitrite,

nitrate, and total phosphorus) shows that elevated

concentrations occur primarily downstream from

urban areas. Sites with five or more years of

record were analyzed for temporal trends in

concentration of nutrient species. Downward
2 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

trends were identified for ammonia and nitrite for

three surface-water sites. For nitrate, no trends

were observed at two sites and a downward trend

was observed at one site. Total phosphorus

showed no trend for the site near the mouth of the

Fraser River. Downward trends in the nutrient

species may reflect changes in the wastewatertreatment facilities in the watershed. Bacteria

sampling completed in the watershed indicates

that more bacteria are present in the water near

urban settings.

The limited ground-water and surfacewater data for the Fraser River watershed provide

a general assessment of the quantity and quality

of these resources. Concentrations of most waterquality constituents generally are less than

ground- and surface-water-quality standards, but

the presence of bacteria, some volatile organic

compounds, methylene blue active substances,

and increased nutrients in the water may indicate

that land use is affecting the water quality.

INTRODUCTION

The Fraser River, which has a drainage area of

about 287 mi2 (fig. 1), flows about 28 mi from an area

along the Continental Divide in the Arapaho National

Forest through the towns of Winter Park, Fraser,

Tabernash, and Granby and empties into the Colorado

River near Granby, Colorado. The Fraser River watershed is located in the southeastern part of Grand

County.

Because of changes in land-use practices in the

Fraser River watershed, there is the potential to see

effects in the overall water quantity and quality in the

watershed. For this reason, the U.S. Geological Survey

(USGS), in cooperation with Grand County and the

Colorado Department of Public Health and Environment, compiled and analyzed information on water

quantity and quality in the Fraser River watershed

through water year 1997. This information was

compiled in order to identify potential concerns that

relate to the effects of changes in land use/land cover

on the quantity and quality of the ground-water and

surface-water resources.

Purpose and Scope

This report presents the available water-quantity

and water-quality data through water year 1997 for the

Fraser River watershed in order to assess the groundwater and surface-water resources. Ground-water data

are available primarily in the Winter Park, Fraser, and

Tabernash areas, whereas surface-water data are available throughout the watershed. The study provides an

assessment of the quantity and quality of the water

resources in relation to land use/land cover. Specific

objectives of this study are to: (1) Characterize

existing water-resources data for the Fraser River

watershed; (2) analyze historical data and assess the

broad-scale geographic and seasonal variability in the

quantity and quality of water in the Fraser River watershed; and (3) summarize, where possible, the changes

in land use/land cover that affect observed water-quantity and water-quality conditions in the Fraser River

watershed.

From 1904 through 1997, the Fraser River

watershed had 81 water-quantity and water-quality

sampling sites (9 ground-water sites and 72 surfacewater sites), which were sampled or measured for

discharge at various times throughout this period of

record. A large percentage of these sites had only one

or two water-quality analyses. The ground-water analyses typically include a more comprehensive suite of

constituents than the surface-water analyses. Eight of

the nine ground-water-sampling sites are located in the

area of Winter Park, Fraser, and Tabernash (fig. 1). For

most ground-water sites, data were available for field

parameters (such as water temperature, specific

conductance, dissolved oxygen, pH, alkalinity, and

turbidity), major ions, nutrients, trace elements, radon,

dissolved organic carbon, pesticides, volatile organic

compounds, bacteria, methylene blue active

substances, and chlorofluorocarbons. For the surfacewater sites, information was available on field parameters (such as water temperature, specific conductance,

dissolved oxygen, pH, and alkalinity), major ions,

nutrients, trace elements, and bacteria. In addition,

some information was available for suspended-sediment concentrations and discharge.
INTRODUCTION 3

Tabernash

Winter

Fraser

Granby

Park

 YMCA

 of the

 Rockies

40

40

Basin boundary

Arapaho

National

Forest

Figure 1. Location of the Fraser River watershed, Grand County, Colorado.
4 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

Acknowledgments

The authors of this report thank the many individuals and agencies that provided water-quantity and

water-quality data for the Fraser River watershed.

Special thanks are extended to Gary Cooper, Silvercreek and Winter Park West Water and Sanitation

District; Bruce Hutchins, Grand County Water and

Sanitation District; Doreen Schmidt, U.S. Forest

Service; and Mike Wajeck, YMCA of the Rockies,

Snow Mountain Ranch. We also thank Stephen Char,

USGS, for his assistance in compiling the waterquality data for the Fraser River watershed.

DESCRIPTION OF STUDY AREA

The Fraser River watershed is located in the

northwestern part of the Southern Rocky Mountains

physiographic province of Colorado (Apodaca and

others, 1996). Land-surface altitude in the watershed

ranges from about 8,000 ft in the valley to about

12,800 ft along the Continental Divide. Daily average

temperatures in the Fraser River watershed range from

a low of 13oF to a high of 55oF. Precipitation in the

watershed on average is less than 20 in/yr in the

valleys north and west of Fraser to more than 40 in/yr

in the higher peaks of the watershed (fig. 2).

The geology of the Fraser River watershed

varies from Precambrian-age basement rocks to

Quaternary alluvial deposits (fig. 3). The oldest rocks

are of Precambrian age and are exposed in the eastern

and southern mountains of the watershed. Fractured

Precambrian rocks generally yield small quantities of

water that are adequate only for domestic supplies.

Where the Precambrian rocks are fractured, water may

discharge from springs. Sedimentary rocks of Triassic,

Jurassic, and Cretaceous age are in the western part of

the watershed and generally are low yielding;

however, water from these sedimentary rocks probably

is suitable for most domestic uses. The geologic units

in the watershed that will yield water more readily are

Tertiary or younger in age (Voegeli, 1965). These units

include the Troublesome Formation and alluvial

deposits in the lower altitudes in the watershed. These

aquifers provide water for residential and municipal

use. The Troublesome Formation is predominantly

siltstone with some interbedded sandstones and

conglomerates and is as much as 1,000 ft thick. The

alluvial deposits consist of alluvial sands and gravels

and older glacial drift and are as much as 200 ft thick.

Land use/land cover in the Fraser River watershed is 71 percent forested (deciduous, evergreen, and

mixed) land; 14 percent cropland, pasture, agricultural, and rangeland; 11 percent tundra, bare ground,

and exposed rock; 2 percent urban; and 2 percent other

land-use classifications (fig. 4). The urban classification includes the categories of other urban, commercial, residential, and mixed urban areas. The major

urban centers in the watershed are Winter Park, Fraser,

and Granby. All land-use/land-cover classifications

were determined during the late 1970's (Fegeas and

others, 1983), and refined with 1990 population data

(Hitt, 1995).

The Fraser River watershed, which is located in

the southeastern part of Grand County, comprises

about 15 percent of the total area of Grand County

(1,869 mi2

). Population of Grand County has

increased about 94 percent between 1970 (4,107) and

1990 (7,966) (U.S. Bureau of the Census, 1970 and

1990). An increase from 1990 population of about

105 percent is projected for Grand County by the year

2020 (16,358) (U.S. Bureau of the Census, 1990).

Populations for the major towns in 1994 for the Fraser

River watershed were Winter Park (660), Fraser (671),

and Granby (1,026) (U.S. Bureau of the Census,

1994). However, these population numbers do not

represent an exact population for the Fraser River

watershed because unincorporated towns are not

included in the 1994 census. In addition, the population census does not reflect the full demand on the

water resources in the area. Primarily during the

winter and summer months, many tourists and vacationers significantly add to the population of the watershed.

DATA SOURCES AND COMPILATION

Many individuals and agencies were contacted

within the Fraser River watershed to obtain waterquantity and water-quality data. These data, summarized in table 1, include information on surface water,

ground water, and springs. Some of these data are

discussed in the report but were not used in the statistical summaries because sampling methods were

unknown and the data could not be quality assured.

Most of the data used in assessing the water-quality
DATA SOURCES AND COMPILATION 5

Tabernash

Winter

Fraser

Granby

Park

EXPLANATION

(in inches per year)

Greater than 40

30 to 40

20 to 30

Less than 20

Figure 2. Average annual precipitation (1951–80) in the Fraser River watershed (Colorado Climate Center, 1984).
6 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997



Tabernash

Winter

Fraser

Granby

Park

 

Qa

Tt 

Tt 

Kmw 

Kmw 

Kmw 

Kp

Kp

Mz

Mz

Mz

Mz

Kp

Mz

Mz Kp

Kc Kc

Xb

Xb

Xb

Xb

Xb

Xb

Xb

Xb

Xb

Xb

Xb

Xb

Xb

Xfh Xfh

Xfh

Xfh

Qdo Qdo

Qd

Qd

Qd

Qd

Qd

Qd

Qd

Qd

Qd

Qdo

Xfh

Xfh

Xfh

Xfh

Xg

KJdm

KJdm

KJdm

KJdm

KJdm

Kmw 

Xg 

Xb 

Xb 

Xg 

Xb 

Xg Xg 

Xg 

Xg 

Tt 

Tt 

Tt 

Tt 

TKi

Tc

Qg Qgo

Qg

Qg

Taf

Yg

Yg

Yg

Yg

Yg

Taf

Taf

Xg

Xg

Xg

Qg

Qg

Figure 3. Geology of the Fraser River watershed (Green, 1992; Tweto, 1979).
DATA SOURCES AND COMPILATION 7

Igneous rocks of Tertiary and/or Cretaceous age

Sedimentary rocks of Tertiary age

Sedimentary rocks of Cretaceous age

Sedimentary rocks of Cretaceous and Jurassic age

Sedimentary rocks broadly classified

Igneous and metamorphic rocks of Precambrian age

Qgo

Qd

TKi

Taf

Tt

Tc

Kmw

Kp

Kc

KJdm

Mz

Yg

Xg

Xb

Xfh

EXPLANATION

Unconsolidated surficial deposits of Quaternary age

Modern alluvium

Gravels and alluviums

Older gravels and alluviums

Glacial drift of Pinedale and Bull Lake Glaciations

Older glacial drift (pre-Bull Lake age)

Laramide intrusive rocks

Ash-flow tuff of main volcanic sequence

Troublesome Formation—Siltstone, sandstone, and conglomerate

Coalmont Formation—Sandstone, shale, coal beds, and conglomerate

Windy Gap Member of Middle Park Formation

Pierre Shale, undivided

Colorado Group

Dakota and Morrison Formations

Mesozoic rocks—Mainly early Cretaceous, Jurassic, and Triassic age

Granitic rock of 1,400 Ma

Granitic rock of 1,700 Ma

Biotite gneiss, schist, and migmatite

Felsic and hornblende gneisses, either separate or interlayered

Qa

Qg

Qdo
8 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

Tabernash

Winter

Fraser

Granby

Park

Transitional areas

Cropland and pasture

Other agricultural land

Deciduous forest

Evergreen forest

Mixed forest

Herbaceous rangeland

Shrub and brush rangeland

Mixed rangeland

Nonforested wetland

Forested wetland

Strip mines

Bare ground

Bare exposed rock

Herbaceous tundra

Shrub and brush tundra

Mixed tundra

Perennial snow

Lakes and reservoirs

EXPLANATION

Other urban

Commercial

Residential

Mixed urban

Figure 4. Land use/land cover for the Fraser River watershed, 1990. [Based on GIRAS (Geographic Information Retrieval and

Analysis System) land-use data from the 1970’s (Fegeas and others, 1983), and refined with 1990 population data (Hitt, 1995)].
DATA SOURCES AND COMPILATION 9

Table 1. Sources of water-related data for the Fraser River watershed[USEPA, U.S. Environmental Protection Agency; MCL, maximum contaminant level; ---, no data]

Source General purpose for collecting information Number of sites

Number

of

samples

per site

Data collected

Period

of

record

Results

ColoradoDepartment ofPublic Health andEnvironment

Fraser River field investigationSampling of Fraser River upstream and

downstream from effluent dischargesto evaluate wastewater-treatmentfacilities

Local Fraser River studyWater-quality investigations of the

 Fraser River

14

7

24

6

4141

Field parameters, discharge, and nutrients1

Field parameters, discharge, and nutrientsField parameters, nutrients, and bacteriaField parameters, major ions, and nutrients, and benthic and fish communities

1982–83198419831977–78

Nutrients were detected in the effluent.Nutrients were detected in the effluent.Nutrients and fecal coliforms were

detected in the effluent.

Results are summarized in report by

Mars, 1979.

Denver WaterBoard

Surface-water-quality data 4 6 or 8 Field parameters, major ions, nutrients,

trace elements, radionuclides, andbacteria data

1992–94 Constituents did not exceed USEPA

stream standards (USEPA, 1986).

Silvercreek Water

and SanitationDistrict

Develop potential ground-water supplies

in the alluvial deposits for use by theplanned Val Moritz development(south of Granby)

6 1 Nutrients, major ions, trace elements, and

aquifer tests

1973–74 Manganese concentrations may be high.

U.S. Forest

Service

Estimation of bedload sediment yieldDetermination of fish population in the

Fraser River

 ---

---

------

------

19961995

Annual sediment introduced into the

Fraser River from activity along U.S.Highway 40 is estimated at 1,300 cubicyards.

Fish populations in the Fraser River are

impacted by sediment loads.

Winter Park West

Water andSanitationDistrict

Inorganic analyses of ground-water

samples

Analyses completed for volatile organic

compounds of ground-water samples

Well construction and aquifer test

reports for eight wells in the FraserRiver valley in the TroublesomeFormation

24

48

11

---

Copper and leadVolatile organic compounds

---

199419931992

Lead levels exceeded the USEPA MCL

drinking-water standards at four sitessampled (USEPA, 1996).

Volatile organic compounds detected were

all less than USEPA MCL drinkingwater standards (USEPA, 1996).

Wells are located in the Troublesome

Formation and are recharged by precipitation.

YMCA of the

Rockies—Snow

MountainRanch

Water-quality analyses for the Ruesch

and Just springs

2 5 Inorganics, nutrients, organics, radiological, and waterborne particulates 1991–94 Constituents did not exceed USEPA MCL drinking-water standards (USEPA,

1996).

1 Field parameters may include dissolved oxygen, pH, specific conductance, and water temperature.
10 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

conditions of the Fraser River watershed were

obtained from two sources: (1) the USGS National

Water Information System (NWIS) and (2) the U.S.

Environmental Protection Agency (USEPA) Storage

and Retrieval (STORET) system. Data from 81 waterquantity and water-quality sampling sites were available for the Fraser River watershed from these

sources, which included 9 ground-water sites and

72 surface-water sites (figs. 5 and 6). Eight of the

nine ground-water wells were completed in the

unconsolidated alluvium and were sampled as part of

the USGS Upper Colorado River Basin (UCOL)

National Water-Quality Assessment (NAWQA)

Program. Twenty-nine of the surface-water sites were

from the USGS NWIS data base.

Water-quality data for the ground-water sites

(fig. 5, table 2) consist of a more comprehensive suite

of constituents analyzed than the surface-water data.

Information was available on field parameters (water

temperature, specific conductance, dissolved oxygen,

pH, alkalinity, and turbidity), major ions, nutrients,

trace elements, radon-222, dissolved organic carbon

(DOC), pesticides, volatile organic compounds

(VOC's), bacteria (total coliform and Escherichia coli

[E. coli] and viruses [somatic coliphage]), methylene

blue active substances (MBAS), and chlorofluorocarbons (CFC's) at most sites.

The surface-water-quality data for the watershed

(table 3) consist of field parameters (water temperature, specific conductance, dissolved oxygen, pH, and

alkalinity), major ions (primarily chloride), nutrients,

trace elements, and other constituents, which include

bacteria and suspended-sediment data. The data for

most of these sites are limited and may include only

one sample per site. The most abundant surface-waterquality data are field parameters, nutrients, and chloride. In figure 7, the distribution of nutrient species

samples for the surface-water sites is shown by date

and period of sampling. In the watershed, surfacewater sites with long-term water-quality data are

limited; only four sites had at least 5 years of record.

METHODS OF DATA REVIEW AND

ANALYSIS

In this report water-quality properties and

constituents are represented graphically and statistically. The ground-water and surface-water data were

quality assured by examining the differences between

the total-cation and total-anion concentrations. Differences between total-cation and total-anion concentrations for all nine wells from the NWIS data base were

less than 10 percent. For the surface-water-quality

sites from the NWIS and STORET data bases, less

than 1 percent of the samples (total of 3,759 waterquality samples) contained cation and anion data. For

these sites the differences between the total-cation and

total-anion charge balance were less than 10 percent.

A difference between the total-cation and the totalanion charge balance of less than 10 percent is

assumed acceptable for this report. Because of the

limited cation and anion data, not all of the data used

in this report were able to be quality assured. However,

laboratory analyses performed by the USGS or by the

other agencies as indicated in table 3 were assumed to

be reliable for the general assessment of the water

quality in the watershed.

Water-quality data were analyzed using

nonparametric statistical methods. Nonparametric

methods were used because they are not strongly influenced by outliers, require few assumptions about the

statistical properties of a data set, and are suitable for

use with small data sets. Water-quality data for

surface-water sites in the basin had many values that

were less than the detection or reporting limits.

Because different laboratory analytical methods were

used for the surface-water sites, the laboratory analytical detection or reporting limits for a given constituent were not consistent. Data that are less than the

detection or reporting limits are censored data. In

order to statistically compare the water-quality data for

a given constituent and not exclude all of the censored

data, these data needed to have a common detection or

reporting limit. For the data used in this report, the

most common detection or reporting limit was kept.

However, values that were censored above the most

common detection or reporting limit were deleted and

censored values below the common detection or

reporting limit were converted to the most common

detection or reporting limit before statistically

analyzing the data.

Boxplots are used to display variability in a data

set. Boxplots (for example, fig. 12) graphically represent the median, or 50th percentile (the centerline of

the box), the interquartile range (the part of the box

representing the range between the 25th and

75th percentile), and the 10th and 90th percentiles (the
METHODS OF DATA REVIEW AND ANALYSIS 11

EXPLANATION

Ground-water site and number

Surface-water site and number

Gaging station and site number

Figure 5. Location of the U.S. Geological Survey (USGS) National Water Information System (NWIS) ground-water-quality

and surface-water-quantity and water-quality sites in the Fraser River watershed.
12 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

Tabernash

Winter

Fraser

Granby

Park

EXPLANATION

Surface-water site and number

Figure 6. Location of the U.S. Environmental Protection Agency (USEPA) Storage and Retrieval (STORET) surface-waterquality sites in the Fraser River watershed.
METHODS OF DATA REVIEW AND ANALYSIS 13

Table 2. Characteristics of ground-water-quality sites from the U.S. Geological Survey (USGS) National Water Information System (NWIS) data base in the Fraser

River watershed

[---, no data; ft, feet; PVC, polyvinyl chloride; USGS, U.S. Geological Survey; FP, field parameters, MI, major ions; N, nutrients; O, other constituents (bacteria, chlorofluorocarbons, and/or methyleneblue active substances); P, pesticides; TE, trace elements; VOC's, volatile organic compounds; land-use/land-cover classifications for the ground-water sites are based on the predominant land use/landcover within a 500-meter radius of the well location]

Site

no.

(fig. 5)

Site identification

number

(latitude-longitude)

Water use1 Well- depth (ft) Static water level below land surface (ft)2 Casing Year constructed Data source Type of data Aquifer Land use/land cover

G1 395507105470200 U 26 3.8 (5.95) PVC 1996 USGS FP, MI, N, O, P,

TE, VOC's

Alluvium Urban

G2 395605106473100 U 22 6.36 (7.85) PVC 1996 USGS FP, MI, N, O, P,

TE, VOC's

Alluvium Rangeland

G3 395623105481000 U 17 0.90 (9.60) PVC 1996 USGS FP, MI, N, O, P,

TE, VOC's

Alluvium Rangeland

G4 395648105485300 U 16 1.94 (2.8) PVC 1996 USGS FP, MI, N, O, P,

TE, VOC's

Alluvium Urban

G5 395658105485400 PS 110 --- Steel 1983 USGS FP, MI, N, O, P,

TE, VOC's

Alluvium Urban

G6 395706105485000 U 18 2.84 (3.55) PVC 1996 USGS FP, MI, N, O, P,

TE, VOC's

Alluvium Urban

G7 395929105510300 U 28 6.97 (9.3) PVC 1996 USGS FP, MI, N, O, P,

TE, VOC's

Alluvium Rangeland

G8 395935105535800 H 115 70 PVC 1968 USGS FP, MI, N, O, P,

TE, VOC's

Alluvium Forest

G9 400248105560300 --- 603 --- --- --- USGS FP, MI, N, TE Middle Park

Formation

Rangeland

1Water use: H, domestic; PS, public supply, U, unused.2Static water level for May 1997; number in parentheses is static water level measured in October 1997.
14 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

Table 3. Characteristics of surface-water-quality sites in the Fraser River watershed[no., number; latitude and longitude = degrees, minutes, and seconds; mi2, square miles; ---, no data; ft, feet; n.d., not determined; CDPHE, Colorado Department of Public Health and Environment; DWB,

Denver Water Board; USEPA, U.S. Environmental Protection Agency; USFS, U.S. Forest Service; USGS, U.S. Geological Survey; FP, field parameters; MI, major ions; N, nutrients; O, other constituents(bacteria and/or suspended sediment); Q, discharge; TE, trace elements; surface-water land-use/land-cover classifications are determined by the land use/land cover upstream from the surface-water site; if

the site was within an urban area, the site was classified as urban]

Site no.

(figs. 5

and 6)

Site name Station identification number Latitude Longitude Drainage area (mi2) Data source Period of record, in water years Type of data Land use/land cover

1 Upper Colorado River, Upper

Vasquez #45

394900105501001 39o49'00'' 105o50'10'' --- USFS 1977–78 FP, O, Q Forest

2 Upper Colorado River, Fraser

River at Berthoud Pass #47

394950105452001 39o49'50'' 105o45'20'' --- USFS 1977 FP, O, Q Forest

3 Fraser River at Upper Station

near Winter Park, CO

09022000 39o50'45'' 105o45'05'' 10.5 USGS 1969–97 FP, MI, N, Q, TE Forest

4 Upper Colorado River, East St.

Louis Creek #42

395050105543001 39o50'50'' 105o54'30'' --- USFS 1977 FP, O, Q Forest

5 Fraser River above Mary Jane 395104105460000 39o51'04'' 105o46'00" --- USGS 1976–77 FP, MI, N, O, Q TE Forest

6 Jim Creek at intake near Tabernash 395212105452501 39o52'12'' 105o45'25" --- DWB 1982 FP, MI, N, O, TE Forest

7 Upper Colorado River, Fraser

River at USGS station #48

395310105484001 39o53'10'' 105o48'40'' --- USFS 1977–78 FP, O, Q Forest

8 Elk Creek at Upper Station near

Fraser, CO

09025300 39o53'22'' 105o49'55'' 1.67 USGS 1996–97 FP, Q Forest

9 Ranch Creek at intake near

Tabernash

395323105450501 39o53'23'' 105o45'05'' --- DWB 1982 FP, MI, N, O, TE Forest

10 Upper Colorado River, Lexen

Creek #55

395330105552001 39o53'30'' 105o55'20'' --- USFS 1977–79 FP, O, Q Forest

11 Fraser River below Buck Creek

at Winter Park, CO

09023750 39o53'33'' 105o45'49'' 25.6 USGS 1990–97 FP, MI, N, Q Forest

12 Upper Colorado River, Upper St.

Louis Creek #44

395340105524001 39o53'40'' 105o52'40'' --- USFS 1977 FP, O, Q Forest

13 Upper Colorado River Basin,

Fraser River

395350105463001 39o53'50'' 105o46'30'' --- CDPHE 1983–84 FP, MI, N Urban

14 Upper Colorado River, Winter

Park WWTP

395350105463301 39o53'50'' 105o46'33'' --- CDPHE 1982–84 FP, MI, N Urban

15 Upper Colorado River, Fool

Creek #40

395350105521001 39o53'50'' 105o52'10'' --- USFS 1977 FP, O, Q Forest

16 Fraser River at Winter Park, CO 09024000 39o54'00'' 105o46'34'' 27.6 USGS 1910–97 FP, MI, N, O, Q, TE Urban

17 Upper Colorado Basin, Fraser

River at USGS gage

395400105463501 39o54'00'' 105o46'35'' --- CDPHE 1982–84 FP, MI, N Urban

18 Upper Colorado River, Dead

Horse Creek #43

395400105544001 39o54'00'' 105o54'40'' --- USFS 1977–79 FP, O, Q Forest
METHODS OF DATA REVIEW AND ANALYSIS 15

Site no.

(figs. 5

and 6)

Site name Station identification number Latitude Longitude Drainage area (mi2) Data source Period of record, in water years Type of data Land use/land cover

19 Upper Colorado River, Main St.

Louis Creek #41

395430105524001 39o54'30'' 105o52'40'' --- USFS 1977 FP, O, Q Forest

20 St. Louis Creek near Fraser, CO 09026500 39o54'36'' 105o52'40'' 32.9 USGS 1934–97 FP, Q Forest21 Fraser River near Fraser 395452105464500 39o54'52'' 105o46'45'' --- USGS 1976–77 FP. MI, N, O, Q, TE Urban22 Fraser River at Winter Park Ski

Resort

12163 39o54'59'' 105o46'34'' --- CDPHE 1996–97 FP, MI, N, O, TE Urban

23 Elk Creek near Fraser, CO 09025400 39o55'09'' 105o49'31'' 7.15 USGS 1971–96 FP, Q Forest24 Vasquez Creek at Winter Park,

CO

09025000 39o55'13'' 105o47'05'' 27.8 USGS 1934–97 FP, Q Urban

25 Upper Colorado River Basin,

Fraser River

395520105465801 39o55'20'' 105o46'58'' --- CDPHE 1984 FP, MI, N Urban

26 Upper Colorado River Basin,

Vasquez

395520105470501 39o55'20'' 105o47'05'' --- CDPHE 1982–84 FP, MI, N Urban

27 St. Louis Creek above Fraser 12165 39o55'22'' 105o51'26'' --- CDPHE 1996–97 FP, MI, N, O, TE Forest28 Fraser River below Vasquez

Creek at Winter Park, CO

09025010 39o55'40'' 105o47'08'' 59.1 USGS 1990–97 FP, MI, N, O, Q, TE Urban

29 Upper Colorado River, South

Fork Ranch #30

395610105455001 39o56'10'' 105o45'50'' --- USFS 1976–78 Q Forest

30 Upper Colorado River Basin,

Fraser River above GrandWWT

395610105472501 39o56'10'' 105o47'25'' --- CDPHE 1982–84 FP, MI, N Urban

31 Upper Colorado River, Crooked

Creek #54

395620105561001 39o56'20'' 105o56'10'' --- USFS 1977 FP, O, Q Forest

32 Upper Colorado River, Grand

County WWTF no. 1

395625105474001 39o56'25'' 105o47'40'' --- CDPHE 1982–84 FP, MI, N Urban

33 Upper Colorado River Basin,

Fraser River below GrandWWT

395628105475501 39o56'28'' 105o47'55'' --- CDPHE 1982–84 FP, MI, N Urban

34 Upper Colorado River, Main

Ranch Creek #29

395630105442001 39o56'30'' 105o44'20'' --- USFS 1978 Q Forest

35 Crooked Creek below Tipperary

Creak near Tabernash, CO

395634105532401 39o56'34'' 105o53'24'' --- USGS 1997 FP, MI, N, O, Q Forest

36 Upper Colorado River, Middle

Fork Ranch Creek #31

395640105454001 39o56'40'' 105o45'40'' --- USFS 1976 Q Forest

Table 3. Characteristics of surface-water-quality sites in the Fraser River watershed—Continued

[no., number; latitude and longitude = degrees, minutes, and seconds; mi2, square miles; ---, no data; ft, feet; n.d., not determined; CDPHE, Colorado Department of Public Health and Environment; DWB,

Denver Water Board; USEPA, U.S. Environmental Protection Agency; USFS, U.S. Forest Service; USGS, U.S. Geological Survey; FP, field parameters; MI, major ions; N, nutrients; O, other constituents(bacteria and/or suspended sediment); Q, discharge; TE, trace elements; surface-water land-use/land-cover classifications are determined by the land use/land cover upstream from the surface-water site; if

the site was within an urban area, the site was classified as urban]
16 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997 Site no. (figs. 5 and 6) Site name Station identification number Latitude Longitude Drainage area (mi2) Data source Period of record, in water years Type of data Land use/land cover 37 Upper Colorado River, Hamilton Creek at Mouth #28 395950105474001 39o59'50'' 105o47'40'' --- USFS 1978 Q Forest 38 Upper Colorado River Basin, Fraser River 395650105485001 39o56'50'' 105o48'50'' --- CDPHE 1984 FP, MI, N Urban 39 St. Louis Creek above Fraser, CO 395659105494700 39o56'59'' 105o49'47'' --- USGS 1976 FP, N, O, Q Range- land 40 Ranch Creek near Fraser, CO 09032000 39o57'00'' 105o45'54'' 19.9 USGS 1957–97 FP, MI, N, O, Q Forest 41 Upper Colorado River Basin, St. Louis Creek 395700105490501 39o57'00'' 105o49'05'' --- CDPHE 1984 FP, MI, N Urban 42 Ranch Creek 3 mi east of US 40 near Fraser 395701105455301 39o57'01'' 105o45'53'' --- DWB 1981 FP, MI, N, O, TE Forest 43 Fraser River below St. Louis Creek at Fraser, CO 09027010 39o57'07'' 105o48'51'' 111 USGS 1956–97 FP, N, Q Urban 44 Upper Colorado River Basin, Fraser River above Fraser WWTP 395750105485001 39o57'50'' 105o48'50'' --- CDPHE 1982–84 FP, MI, N Urban 45 Upper Colorado River, Fraser WWTP 395810105485201 39o58'10'' 105o48'52'' --- CDPHE 1982–84 FP, MI, N Urban 46 Upper Colorado, Fraser River 300 ft below Fraser WWTP 395820105485101 39o58'20'' 105o48'51'' --- CDPHE 1982–83 FP, MI, N Urban 47 Pole Creek at Upper Station near Tabernash, CO 395901105550800 39o59'01'' 105o55'08'' --- USGS 1997 FP, MI, N, O, Q Range- land 48 Cabin Creek near Fraser, CO 09032100 39o59'09'' 105o44'40'' 4.87 USGS 1984–97 FP, Q Forest 49 Fraser River at Tabernash, CO 09027100 39o59'25'' 105o49'44'' 116 USGS 1990–97 FP, MI, N, Q, TE Urban 50 Pole Creek near Tabernash 12164 39o59'29'' 105o51'07'' --- CDPHE 1996–97 FP, MI, N, O, TE Range- land 51 Upper Colorado River, Ranch Creek 395930105493001 39o59'30'' 105o49'30'' --- CDPHE 1982–83 FP, MI, N Range- land 52 Upper Colorado River, Fraser near Tabernash 395930105494501 39o59'30'' 105o49'45'' --- CDPHE 1982–84 FP, MI, N Urban 53 Pole Creek at Mouth near Taber- nash, CO 395930105510700 39o59'30'' 105o51'07'' --- USGS 1997 FP, MI, Q Range- land 54 Upper Colorado River, Pole Creek 395945105510501 39o59'45'' 105o51'05'' --- CDPHE 1982–83 FP, MI, N Range- land Table 3. Characteristics of surface-water-quality sites in the Fraser River watershed—Continued [no., number; latitude and longitude = degrees, minutes, and seconds; mi2, square miles; ---, no data; ft, feet; n.d., not determined; CDPHE, Colorado Department of Public Health and Environment; DWB, Denver Water Board; USEPA, U.S. Environmental Protection Agency; USFS, U.S. Forest Service; USGS, U.S. Geological Survey; FP, field parameters; MI, major ions; N, nutrients; O, other constituents (bacteria and/or suspended sediment); Q, discharge; TE, trace elements; surface-water land-use/land-cover classifications are determined by the land use/land cover upstream from the surface-water site; if the site was within an urban area, the site was classified as urban]
METHODS OF DATA REVIEW AND ANALYSIS 17

Site no.

(figs. 5

and 6)

Site name Station identification number Latitude Longitude Drainage area (mi2) Data source Period of record, in water years Type of data Land use/land cover

55 Ranch Creek below Meadow

Creek near Tabernash, CO

09033100 39o59'57'' 105o49'37'' n.d. USGS 1997 FP, MI, N, O, Q Rangeland

56 Ranch Creek near Tabernash,

CO

395957105493900 39o59'57'' 105o49'39'' --- USGS 1976 FP, N, O, Q Rangeland

57 Upper Colorado River, Hurd

Creek at Mouth #27

400000105475001 40o00'00'' 105o47'50'' --- USFS 1976 Q Forest

58 Fraser River below Crooked

Creek at Tabernash, CO

400009105504600 40o00'09'' 105o50'46'' 4.87 USGS 1991–94 FP, N, Q Urban

59 Meadow Creek at mouth near

Tabernash, CO

400016105490800 40o00'16'' 105o49'08'' n.d. USGS 1997 FP, Q Forest

60 Fraser River below Tabernash,

CO

400220105525000 40o02'20'' 105o52'50'' --- USGS 1976–77 FP, N, O, Q Urban

61 Fraser River at Hwy. 40 at

Granby, CO

400453105554200 40o04'53'' 105o55'42'' --- USGS 1995 FP, MI, N, Q, TE Urban

62 Fraser River above Granby near

Granby, CO

400454105554500 40o04'54'' 105o55'45'' --- USGS 1976 FP, N, O, Q Urban

63 Upper Colorado River, Fraser

River near Granby, CO

400454105554201 40o04'54'' 105o55'42'' --- CDPHE 1979–92 FP, MI, N, O, TE Urban

64 Upper Colorado River Basin,

Fraser River

400500105571001 40o05'00'' 105o57'10'' --- CDPHE 1984 FP, MI, N Urban

65 Fraser River below Granby, CO 400505105571201 40o05'05'' 105o57'12'' --- USGS 1977–79 FP, MI, N, Q, TE Urban66 Upper Colorado River, Fraser

River

400505105572001 40o05'05'' 105o57'20'' --- CDPHE 1982–84 FP, MI, N Urban

67 Fraser River at Granby, CO 09034000 40o05'07'' 105o57'17'' 297 USGS 1904–09

1938–55

FP, Q Urban

68 Strawberry Creek near Granby,

CO

09033500 40o05'12'' 105o47'39'' 11.6 USGS 1936–45

1983

Q Forest

69 Upper Colorado River Basin,

Fraser River

400515105573001 40o05'15'' 105o57'30'' --- CDPHE 1984 FP, MI, N, TE Urban

70 Meadow Creek at Divide near

Tabernash, CO

400530105463001 40o05'30'' 105o46'30'' --- DWB 1981 FP, MI, N, O Forest

71 Fraser River near Mouth near

Granby, CO

400550105581800 40o05'50'' 105o58'18'' --- USGS 1995 FP, MI, N, Q, TE Urban

72 Fraser River, Granby Sanitation 401000105580001 40o10'00'' 105o58'00'' --- USEPA 1974–83 FP, MI, N, O Urban

Table 3. Characteristics of surface-water-quality sites in the Fraser River watershed—Continued

[no., number; latitude and longitude = degrees, minutes, and seconds; mi2, square miles; ---, no data; ft, feet; n.d., not determined; CDPHE, Colorado Department of Public Health and Environment; DWB,

Denver Water Board; USEPA, U.S. Environmental Protection Agency; USFS, U.S. Forest Service; USGS, U.S. Geological Survey; FP, field parameters; MI, major ions; N, nutrients; O, other constituents(bacteria and/or suspended sediment); Q, discharge; TE, trace elements; surface-water land-use/land-cover classifications are determined by the land use/land cover upstream from the surface-water site; if

the site was within an urban area, the site was classified as urban]
18 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998

YEAR

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

SITE NUMBER (FIGURES 5 AND 6 AND TABLE 3)

Sampling period

Sampling date

Figure 7. Distribution of sampling dates and period of record for the National Water Information System (NWIS) and the

Storage and Retrieval (STORET) surface-water sites for nutrient data collected in the Fraser River watershed.
METHODS OF DATA REVIEW AND ANALYSIS 19

lines to the boundary points of the boxplot). If analytical values fall outside the 10th and 90th percentile

(outliers), they are represented on the boxplots as

circles above and below these percentile values on the

boxplots.

Nutrient data in this report have been grouped

into equivalent nitrogen and phosphorus species using

methods described in Mueller and others (1995). The

reason for grouping the nutrient species is that nutrient

species have been collected for various reasons and are

reported in different ways in the data bases. In examining the spatial distribution of nutrients in the watershed, the following nutrient species are discussed:

ammonia as N (hereinafter referred to as ammonia);

nitrite as N (hereinafter referred to as nitrite); nitrate as

N (hereinafter referred to as nitrate); orthophosphate

as P (hereinafter referred to as orthophosphate); and

total phosphorus. To evaluate the spatial distributions

of nutrient species in the watershed, the site location

and the median nutrient concentrations were entered

into a geographic information system (GIS) file and

are represented graphically. Trends were evaluated

using the surface-water nutrient data, as they are

useful in showing the temporal variability at individual

water-quality sites and among sites.

Four sites in the watershed had sufficient data

for statistical trend tests. The seasonal Kendall test

(Hirsch and others, 1991), a nonparametric test, was

used to determine if the trend analysis shows whether

or not nutrient concentrations have changed over time.

This test accounts for seasonal effects on concentration by only comparing data within the same season.

Flow-adjusted concentrations were not used in the

trend analysis because no correlations were observed

between discharge and concentration by plotting the

data on normal, log-normal, and log-log plots. In addition, constituents having greater than 10 percent of the

data censored were not flow adjusted because flow

adjustment is not possible with nonparametric procedures when a high percentage of the data are censored

(Hirsch and others, 1991). Sites used for calculating

trends have at least 5 years of record with a minimum

of quarterly sampling. In addition, at least one-half of

the possible number of seasonal, pairwise data

comparisons must have been present in the first and

last thirds of the record (Lanfear and Alexander,

1990). For the sites used in determining trends, not

more than 50 percent of the data were censored.

The water-quality data have been compared to

drinking-water standards and stream-segment standards, where applicable. Drinking-water standards

include the primary (MCL), secondary (SMCL), and

proposed (PMCL) USEPA maximum contaminant

levels established for drinking water, maximum

contaminant level goals (MCLG), drinking-water

advisory (DWA), and health advisory (HA) standards

(U.S. Environmental Protection Agency, 1996).

USEPA drinking-water standards are defined as the

permissible level of a contaminant in water as delivered to users of a public water system. MCL’s are

health related and legally enforceable, whereas

SMCL’s apply to the esthetic qualities of water and are

recommended levels. PMCL’s are proposed levels that

are not currently enforceable. MCLG's are nonenforceable concentrations of a drinking-water contaminant that are intended for protection against adverse

human health effects. DWA is intended to protect

against taste and odor problems. The USEPA HA's

used in this report are defined as the concentration of a

contaminant in drinking water that is expected to

cause adverse, but noncarcinogenic, effects over a lifetime of typical exposure. The typical exposure

assumes that a 70-kilogram adult drinks 2 liters of

such water per day for 70 years (U.S. Environmental

Protection Agency, 1996). Stream-segment standards

include aquatic-life chronic and acute values, and

table-value standards for selected elements, which are

calculated on the basis of hardness of the water (Colorado Water Quality Control Commission, 1996). Field

temperature and pH are used in determining the coldwater chronic and acute values for ammonia in surface

water (Colorado Water Quality Control Commission,

1996).

Land-use/land-cover classifications for the

ground-water sites are based on the predominant land

use/land cover within a 500-meter radius of the well

location. Surface-water land-use/land-cover classifications are determined by the land use/land cover

upstream from the surface-water site; if the site was

within an urban area, the site was classified as urban.

For example, the area from Winter Park to Fraser

would have a predominant land-use/land-cover classification of urban even though urban development is

not continuous between these towns. Land-use/landcover classifications used in the analysis of the data

were grouped into forest (includes deciduous, evergreen, and mixed forest), rangeland (includes all
20 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

rangeland classifications as well as cropland, pasture,

and agriculture), and urban (other urban, commercial,

residential, and mixed urban) land use (fig. 4). These

land-use classifications include the predominant land

use/land cover for the ground-water and surface-water

sites in the watershed.

GROUND WATER

Water Quantity

Water-level measurements obtained from the

Colorado Division of Water Resources well permit

data base were used to generate a generalized watertable map (fig. 8) for part of the watershed upstream

from Tabernash. The wells in this area (fig. 3) were

completed in the alluvial and Troublesome Formation

aquifers. To limit the seasonal variability of the water

table, only fall (August, September, and October)

water-level measurements were used to compile this

map from 129 wells. Water-level information is available for wells installed between 1960 and 1996.

Ground-water flow directions are from higher altitudes

to lower altitudes in the watershed and generally

follow topography. The depth to water in the area

ranged from 3 to 240 ft. The water-table map was

constructed using 100-ft contour intervals because of

limited data and uncertainties with the data. The

uncertainties are related to the accuracy of the well

locations and to the possibility that the water-level

measurements, which are taken upon completion of

drilling, may not reflect the static water level.

Common yields for wells in alluvial aquifers in

the Upper Colorado River Basin range from 5 to

100 gal/min but can exceed 500 gal/min

(U.S. Geological Survey, 1985). Results from aquifer

tests of the alluvial aquifer near Granby indicate that at

a depth of about 15 ft the alluvial aquifer yields

100 gal/min with only a few feet of drawdown

(Voegeli, 1965). Transmissivity for the alluvial aquifer

near Granby was 12,000 gpd/ft. Near the town of

Fraser, aquifer tests conducted in 1994 from wells

installed in the Troublesome Formation indicated

yields that ranged from 110 to 220 gal/min and transmissivities that ranged from 5,000 to 11,000 gpd/ft

(Winter Park West Water and Sanitation District,

written commun., 1997).

The available ground-water resources for the

watershed can be estimated on the basis of the saturated thickness of the aquifers and their specific yield.

The areal extent of the exposed Troublesome Formation and the alluvial deposits in the Fraser River watershed upstream from Tabernash is about 52 mi2 (Green,

1992; Tweto, 1979). This area was selected for estimating the ground-water reserves because of the likelihood that these aquifers will provide water for a part

of the watershed that is being affected by increasing

urban development. In order to calculate ground-water

reserves, a few assumptions were made. Saturated

thickness for the aquifers was assumed to be 400 ft

with a specific yield ranging from 0.12 to 0.2 (Fetter,

1994; Bishop-Brogden Associates, Inc., written

commun., 1997). Total estimated volume of ground

water available from the Troublesome Formation and

the overlying alluvium ranges from about 1.6 to

2.7 million acre-ft. The specific yield for the aquifers

is believed to be variable as a result of changes in the

lithology of the Troublesome Formation. The lower

specific yield used to calculate ground-water reserves

is representative of a fine sand and shale aquifer

(Fetter, 1994) and the higher specific yield value is

more representative of a sand and gravel alluvial

aquifer (Wilson, 1965). Additional information is

needed to obtain a more accurate calculation of the

ground-water reserves in the alluvial and Troublesome

Formation aquifers upstream from Tabernash.

Water Quality

Historical ground-water-quality data for the

Fraser River watershed consist of one site sampled in

1974 from the Middle Park Formation along the

Tenmile Creek drainage (G9, fig. 5). Ground-waterquality data collected by the UCOL NAWQA Program

provides information from 1997 on water-quality

conditions in the alluvial aquifer in the area from

Winter Park to Tabernash (fig. 5). Six monitoring

wells were installed in the alluvium as part of the

UCOL NAWQA Program in 1996 and were sampled

for water-quality constituents in May and October of

1997 (G1–G4, G6, and G7, table 2). The wells were

installed following the NAWQA Program protocols in

order to limit possible contamination of the waterquality constituents and properties (Lapham and

others, 1995). The purpose of this sampling was to

provide information on water-quality conditions in an
GROUND WATER 21

8 500 8500 8500 8400

858400 00

8400

86 00

85

8400 00

8400

8400 8 400

8400

86

8500

00 8 600

8700

88 00

85 00

8500 8500

8900

8600

8500

8500

8600

8900

8600

8800

8600

8700

8600

8700

8600

8800

8600 86 00

8700

8600

8 9 00

90 00

8700 8700 8700 8700

8800

8800

8 900 8900

8800

8800

8800

8900

8 9 00

9000

90 00

8800

9000

88

00

90 00

8 9 00

9000 9000

8 900

8900

9 0 00

9000

8700

0

870 0

8700

0

8400

84 00

0

8800

EXPLANATION

Water-table contour, shows altitude of water table (Contour interval is 100 feet)

Well

0

0 1

1 2

2

3

3

4 KILOMETERS

4 MILES

Figure 8. Generalized water-table map for the alluvial and Troublesome Formation aquifers upstream from Tabernash in the

Fraser River watershed (1960–96).
22 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

area that is undergoing increasing urban development.

These wells were installed to assess the effects of land

use on the ground-water quality. In addition, two preexisting wells in the alluvium were sampled in the

watershed in September 1997 (G5 and G8, table 2).

These wells were sampled as part of another UCOL

NAWQA study, which was designed to describe waterquality conditions in alluvial aquifers in the Southern

Rocky Mountains physiographic province.

All ground-water sites were sampled in accordance with the procedures and protocols of the

NAWQA Program as described in Koterba and others

(1995). Field parameters, which included specific

conductance, pH, temperature, dissolved oxygen,

alkalinity, and turbidity, were measured at all sites.

Samples collected from the sites were analyzed for

major ions, nutrients, trace elements, radon-222,

DOC, 87 pesticides (pre-existing wells were sampled

for only 47 pesticides), and 87 VOC's. The following

analytical methods were used: Inorganics, various

methods (Fishman and Friedman, 1989); Radon-222,

liquid scintillation counting (American Society for

Testing and Materials, 1992); DOC, ultraviolet (UV)

promoted persulfate oxidation and infrared spectrometry (Brenton and Arnett, 1993); Pesticides, solidphase extraction (SPE) technology on a C-18 cartridge

and gas chromatography/mass spectrometry (Zaugg

and others, 1995); and VOC's, purge and trap capillary

gas chromatography/mass spectrometry (Rose and

Schroeder, 1995).

Ground-water samples collected for the study

also were analyzed for total coliform and E. coli by

using the mENDO and NA-MUG method (American

Public Health Association and others, 1992; Britton

and Greeson, 1989; U.S. Environmental Protection

Agency, 1991). This method allows all positive total

coliform membranes to be transferred to a NA-MUG

plate in order to determine if total coliform colonies

are positive for E. coli. Four sites were analyzed for

total coliform using an MI agar (Brenner and others,

1993), and these same sites were analyzed for somatic

coliphage (Sobsey and others, 1995). Ground-water

samples analyzed for bacteria were collected in a sterilized (autoclaved) bottle using a peristaltic pump with

autoclaved tubing. In May 1997, samples were

analyzed for CFC's (Plummer and others, 1993).

Quality-control and quality-assurance samples

were collected during these sampling efforts and

represented about 10 percent of the total samples

collected. Water-quality samples were analyzed at the

USGS National Water Quality Laboratory in Arvada,

Colo., and CFC's were analyzed at the USGS CFC

Laboratory in Reston, Va.

OCCURRENCE OF INORGANIC COMPOUNDS

Table 4 provides a summary of the water-quality

properties and constituents for the eight shallow alluvial wells sampled (total of 14 samples) in the Fraser

River watershed by the UCOL NAWQA Program and

also indicates the USEPA drinking-water and HA standards. Appendix I lists all properties and constituents

measured and analyzed for the ground-water samples

collected as part of the UCOL NAWQA Program. The

pH values ranged from 5.8 to about 7.6 with a median

value of about 6.6. USEPA SMCL’s for pH, which are

recommended values, range from 6.5 to 8.5 (table 4).

For the Fraser River watershed 28 percent of the

samples (4 of 14) were below the 6.5 pH value.

Dissolved oxygen ranged from 0.10 to 5.87 mg/L,

with values less than 0.3 mg/L at half the sites.

Dissolved-oxygen values of less than 1.0 mg/L can be

considered low values for the Fraser River watershed.

The odor of hydrogen sulfide was apparent at some of

the sites with the very low dissolved-oxygen concentrations, indicating anaerobic conditions.

Major ion chemistry of the ground-water

samples showed that the dominant ions were calcium,

chloride, and bicarbonate. For some of the wells,

sulfate also was a major anion. Ground-water composition is dependent upon the interactions between the

water and soil and minerals present in the aquifer

material through which the water had moved. In the

waters sampled, most inorganic constituents were less

than drinking-water standards; however, a few inorganic constituents exceeded drinking-water standards.

The USEPA SMCL for dissolved iron (300 μg/L) was

exceeded in 50 percent of the samples (7 of 14). High

iron concentrations in drinking water form red precipitates that stain laundry and plumbing fixtures (Hem,

1992). For dissolved manganese, the USEPA SMCL

(50 μg/L) was exceeded in 71 percent of the samples

(10 of 14). High manganese concentrations in drinking

water can cause a brown discoloration of the water and

affect the taste of the water. In addition, high concentrations of manganese in drinking water are undesirable because of the tendency to deposit black-oxide

stains (Hem, 1992). The presence of high concentrations of iron and manganese in the ground water is

probably a function of the surrounding geology (sedi-
GROUND WATER 23

Table 4. Summary of the minimum, median, and maximum values for the ground-water-quality properties and constituents for

wells sampled for the Upper Colorado River Basin (UCOL) NAWQA study

[---, no data; <, less than; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; μg/L, micrograms per liter; NTU, nephelometric turbidity units; cols/100 mL, colonies per 100 milliliters; pfu, plaque-forming units; pCi/L, picocuries per liter; USEPA, U.S. Environmental Protection Agency; MCL, maximum contaminant level; SMCL, secondary maximum contaminant level; PMCL, proposed maximum contaminant level; MCLG,

maximum contaminant level goal; DWA, drinking-water advisory; HA, health advisory level]

Properties, constituents, and reporting unit

Number of

analyses/

number of

detections

Minimum Median Maximum

USEPA drinkingwater standards or

health advisories

Water temperature (degrees Celsius) 14/14 5.20 8.45 16.5 ---

Specific conductance, field (μS/cm) 14/14 94.0 185 717 ---

Dissolved solids (mg/L) 14/14 61.0 117 376 500 (SMCL)

Hardness, total (mg/L as CaCO3) 14/14 24.0 66.5 200 ---

Oxygen, dissolved (mg/L) 14/14 0.10 0.32 5.87 ---

pH, field (standard units) 14/14 5.8 6.6 7.6 6.5-8.5 (SMCL)

Alkalinity, lab (mg/L as CaCO3) 14/14 37.2 68.3 179 ---

Turbidity (NTU) 14/14 0.2 3.2 46 ---

Major ions

Bicarbonate, dissolved (mg/L) 14/14 45.4 83.4 219 ---

Calcium, dissolved (mg/L) 14/14 7.0 19.8 68.4 ---

Chloride, dissolved (mg/L) 14/14 0.69 5.89 85.6 250 (SMCL)

Fluoride, dissolved (mg/L) 14/14 0.16 0.23 0.40 2.0 (SMCL)

Magnesium, dissolved (mg/L) 14/14 1.58 3.85 12.9 ---

Potassium, dissolved (mg/L) 14/14 1.06 1.91 4.31 ---

Silica, dissolved (mg/L as SiO2) 14/14 10.0 22.8 34.9 ---

Sodium, dissolved (mg/L) 14/14 5.08 7.38 37.8 ---

Sulfate, dissolved (mg/L) 14/14 0.24 1.92 7.20 250 (SMCL)

Nutrients

Ammonia, dissolved (mg/L as N) 14/5 0.02 0.15 0.55 30 (HA)

Nitrite, dissolved (mg/L as N) 14/3 <0.01 <0.01 0.06 1.0 (MCL)

Nitrate, dissolved (mg/L as N) 14/7 <0.05 0.07 1.44 10 (MCL)

Orthophosphate, dissolved (mg/L as P) 14/10 <0.01 0.03 0.65 ---

Trace elements

Aluminum, dissolved (μg/L) 14/14 3.75 8.55 55.9 50-200 (SMCL)

Antimony, dissolved (μg/L) 14/0 <1.0 <1.0 <1.0 6.0 (MCL)

Arsenic, dissolved (μg/L) 14/7 <1.0 <1.0 4.7 50 (MCL)

Barium, dissolved (μg/L) 14/14 12.5 36.7 317 2,000 (MCL)

Beryllium, dissolved (μg/L) 14/0 <1.0 <1.0 <1.0 4.0 (MCL)

Boron, dissolved (μg/L) 14/14 7.38 20.7 43.3 ---

Cadmium, dissolved (μg/L) 14/0 <1.0 <1.0 <1.0 5.0 (MCL)

Chromium, dissolved (μg/L) 14/13 <1.0 2.39 6.53 100 (MCL)

Cobalt, dissolved (μg/L) 14/4 <1.0 <1.0 4.58 ---

Copper, dissolved (μg/L) 14/8 <1.0 1.31 48.0 1,300 (action level)

Iron, dissolved (μg/L) 14/14 3.0 319 49,890 300 (SMCL)

Lead, dissolved (μg/L) 14/1 <1.0 <1.0 1.03 15 (action level)

Manganese, dissolved (μg/L) 14/12 <1.0 242 2,801 50 (SMCL)

Molybdenum, dissolved (μg/L) 14/8 <1.0 1.40 4.07 ---

Nickel, dissolved (μg/L) 14/7 <1.0 1.20 4.19 100 (MCL)

Selenium, dissolved (μg/L) 14/0 <1.0 <1.0 <1.0 50 (MCL)
24 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

Properties, constituents, and reporting unit

Number of

analyses/

number of

detections

Minimum Median Maximum

USEPA drinkingwater standards or

health advisories

Trace elements—Continued

Silver, dissolved (μg/L) 14/0 <1.0 <1.0 <1.0 100 (SMCL)

Uranium, dissolved (μg/L) 14/2 <1.0 1.06 2.55 20 (PMCL)

Zinc, dissolved (μg/L) 14/4 <1.0 <1.0 257 5,000 (SCML)

Volatile organic compounds

1,1-Dichloroethane (μg/L) 14/1 --- 0.19 --- ---

123-Trimethylbenzene (μg/L) 14/1 --- 2.13 --- ---

124-Trimethylbenzene (μg/L) 14/2 8.65 10.2 11.8 ---

135-Trimethylbenzene (μg/L) 14/1 --- 1.13 --- ---

Acetone (μg/L) 14/1 --- 7.54 --- ---

Benzene (μg/L) 14/1 --- 0.66 --- 5.0 (MCL)

Ethylenebenzene (μg/L) 14/1 --- 3.52 --- 700 (MCL)

Isodurane (μg/L) 14/1 --- 6.86 --- ---

Isopropyl-benzene (μg/L) 14/1 --- 9.37 --- ---

M/p xylene unfiltered (μg/L) 14/1 --- 11.2 --- ---

Methyl ethyl ketone (μg/L) 14/1 --- 6.11 --- ---

Methyl tert-butyl ether (MTBE) (μg/L) 14/1 --- 0.29 --- 20-40 (DWA)

Napthalene (μg/L) 14/1 --- 5.57 --- ---

N-butyl-benzene (μg/L) 14/1 --- 3.58 --- ---

N-propyl-benzene (μg/L) 14/2 1.29 4.72 8.14 ---

P-isopropyltoluene (μg/L) 14/1 --- 0.27 --- ---

Sec-butyl-benzene (μg/L) 14/2 2.81 3.22 3.62 ---

Toluene (μg/L) 14/1 --- 1.2 --- 1,000 (MCL)

Toluene O-ethyl (μg/L) 14/2 16.8 18.7 20.6 ---

Total O-xylene (μg/L) 14/1 --- 1.27 --- ---

Other constituents

Carbon, organic, dissolved (mg/L as C) 14/14 0.60 3.40 7.30 ---

Coliforms, total, m-ENDO agar (cols/100 mL) 14/1 <1 <1 80 0 (MCLG)

Coliforms, total, MI agar (cols/100 mL) 4/2 <1 7 55 0 (MCLG)

Coliphage, E. coli (pfu) 4/3 <1 5 37 0 (MCLG)

Methylene blue active substances (MBAS)

 (mg/L)

8/4 <0.02 0.03 0.12 ---

Radon-222, total (pCi/L) 14/14 305 3,159 5,943 300 (PMCL)

Table 4. Summary of the minimum, median, and maximum values for the ground-water-quality properties and constituents for

wells sampled for the Upper Colorado River Basin (UCOL) NAWQA study—Continued

[---, no data; <, less than; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; μg/L, micrograms per liter; NTU, nephelometric turbidity units; cols/100 mL, colonies per 100 milliliters; pfu, plaque-forming units; pCi/L, picocuries per liter; USEPA, U.S. Environmental Protection Agency; MCL, maximum contaminant level; SMCL, secondary maximum contaminant level; PMCL, proposed maximum contaminant level; MCLG,

maximum contaminant level goal; DWA, drinking-water advisory; HA, health advisory level]
GROUND WATER 25

mentary rocks) and the low dissolved oxygen. The

USEPA SMCL for dissolved aluminum (ranges from

50 to 200 μg/L) was exceeded in 7 percent of the

samples (1 of 14). The drinking-water standard for

aluminum is for control of odor and taste effects.

Nutrient concentrations at all sites were less

than drinking-water standards. The most frequently

detected nutrient species were orthophosphate and

nitrate. Median nutrient concentrations were less than

0.2 mg/L. The maximum nitrate concentration of

1.44 mg/L occurred at site G3 in May 1997.

Radon-222 is a natural decay product of

uranium and occurs in soils and rocks. Radon-222 was

detected in all wells sampled and ranged in concentration from 305 to 5,943 pCi/L. All of the wells sampled

exceeded the USEPA PMCL of 300 pCi/L, which has

currently been withdrawn pending further review

(U.S. Environmental Protection Agency, 1996). Once

a new standard for radon is finalized, ground water in

the Fraser River watershed may require treatment

before it is used for human consumption. Radon gas,

which causes lung cancer, can enter the home

through water use, such as showering or by infiltration

into the house from the surrounding ground

(U.S. Environmental Protection Agency and others,

1992).

The highest radon-222 concentrations were in

the wells located near the towns of Winter Park and

Fraser (sites G1–G5, and G7 [fig. 5]). Radon-222

concentrations that exceed the PMCL of 300 pCi/L are

not uncommon (Paulsen, 1991). Uranium-bearing

minerals are found in association with Precambrian

rocks, which are present in the Fraser River watershed.

Seasonal variations in the ground-water quality

for the six monitoring wells (G1–G4, G6, and G7

[fig. 5]) are indicated by comparison between the May

data and the October data. Spring to fall water-tablelevel measurements dropped from about 1 to 9 ft at

these six sites (table 2). Figure 9 shows the distribution

of selected water-quality data for the six monitoring

wells and the median concentrations. Generally, the

median concentration for a given constituent was

about the same or slightly higher in the spring than in

the fall sampling. For example, median specificconductance values decreased from 204 μS/cm in the

spring to 173 μS/cm in the fall, and median sulfate

concentrations also decreased from 3.38 to 1.92 mg/L.

Higher concentrations in the spring may be a result of

the increased exposure of the ground water to the

surrounding geology. However, median concentrations

for iron and manganese were similar for both seasons.

For land-use/land-cover classifications, the urban sites

typically had higher median concentrations for

selected water-quality constituents than for rangeland.

More ground-water-quality data are needed to more

accurately determine the changes in the water quality

related to seasonal variations and different land

use/land cover.

In addition to the water-quality samples

collected by the UCOL NAWQA Program, a groundwater site (site G9 [fig. 5]) in the Tenmile Creek

drainage was sampled in 1974 for major ions, nutrients, and trace elements. This well has a depth of

603 ft and is completed in the Middle Park Formation;

therefore, the water quality in this well might be

expected to be different than the water quality for the

shallower aquifers listed in table 2. Nutrient concentrations at this site met all drinking-water standards,

and the concentrations for iron (2,900 μg/L) and

manganese (80 μg/L) exceeded the SMCL for these

elements. Also, water-quality constituents that were

sampled in the ground water as described in table 1

were generally less than USEPA MCL drinking-water

standards. However, manganese concentrations may

exceed drinking-water standards in an alluvial aquifer

south of Granby and lead concentrations also may

exceed drinking-water standards as described in

table 1 (Silvercreek Water and Sanitation District and

Winter Park West Water and Sanitation District).

OCCURRENCE OF ORGANIC COMPOUNDS

Information on the organic compound concentrations is summarized in table 4. Dissolved organic

carbon concentrations ranged from 0.60 to 7.30 mg/L,

with a median concentration of 3.40 mg/L. Elevated

concentrations of DOC in ground water are typically

accompanied by low concentrations of dissolved

oxygen and elevated concentrations of reduced

species, such as dissolved iron and manganese, indicating anaerobic conditions. Microbial activity probably is an important factor contributing to these

reduced conditions.

No pesticides were detected in the eight UCOL

NAWQA wells sampled in the watershed (appendix I).

Volatile organic compounds were detected at site G1

(urban site) and site G2 (rangeland site). Eighteen

VOC's were detected at site G1 in May, but only
26 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

0 0 

EXPLANATION

Number of samples

Data values

Median concentration

Figure 9. Distribution of (a) specific conductance, (b) sulfate, (c) iron, and (d) manganese for spring and fall sampling and by

land-use/land-cover classifications for Upper Colorado River Basin (UCOL) NAWQA ground-water sites.
GROUND WATER 27

four VOC's were detected at site G1 in October, all at

lower concentrations. The VOC's detected at this site

are most likely associated with petroleum by-products,

but the exact source is difficult to ascertain because the

hydrocarbons are degraded. The presence of VOC's at

site G1 probably is a result of the previous land use at

this site. No drinking-water standards for VOC's were

exceeded at this site. At site G2, no VOC's were

detected in May, but two VOC's (methyl tert-butyl

ether [MTBE] and 1,1-dichloroethane) were detected

in October. Neither of these two VOC's were detected

at site G1. MTBE is commonly used as a gasoline

oxygenate and was detected at site G2 at concentrations less than the 20–40 μg/L DWA (U.S. Environmental Protection Agency, 1996). The compound

1,1-dichloroethane is a chlorinated solvent, which can

be used as a degreaser and in the manufacture of some

carbon-based products such as plastics, rubber,

perfumes, and lacquers but has no drinking-water standard (Kolpin and others, 1997). The occurrence of

VOC's at this site may be a result of stormwater runoff

from roads and/or parking lots.

All eight ground-water sites sampled by the

UCOL NAWQA Program were analyzed for total

coliform and E. coli bacteria. Bacteria are analyzed to

assess the sanitary quality of water and potential

health risk from waterborne diseases (Meyers and

Sylvester, 1997). Total coliform bacteria are not typically disease causing but are correlated to the presence

of several waterborne disease-causing organisms

(pathogens). The presence of E. coli is a better indication of fecal contamination. Of the 14 samples

analyzed, 3 samples were positive for total coliform

(21 percent). The sites that contained total coliform

bacteria were sites G3 (rangeland site) and G4 (urban

site) (fig. 5 and table 2). Total coliform bacteria were

detected during the May and October sampling at site

G4 and only detected in the May sampling at site G3.

The concentrations for total coliform for these two

sites ranged from 13 to 80 cols/100 mL. E. coli was

not present at any of the sites sampled. Maximum

contaminant level goals (MCLG's) for total coliform

bacteria in a drinking-water supply are zero

(U.S. Environmental Protection Agency, 1996). The

detection of as few as 4 cols/100 mL of total coliform

bacteria and 1 col/100 mL of E. coli warrants concern

for public health (Meyers and Sylvester, 1997).

Sources of fecal bacteria may include septic system

failures, improper septic system construction or

design, field runoff from rangeland sites, and wastewater-treatment facilities.

Four ground-water sites were analyzed for

somatic coliphage. The highest concentration of

coliphage in the ground water was from site G4 (urban

site), which had a concentration of 37 plaque-forming

units (pfu). Site G4 is located downstream from a

wastewater-treatment facility. The other ground-water

sites analyzed for coliphage were site G3 (6 pfu),

site G6 (4 pfu), and site G7 (0 pfu). Coliphage generally is detected in high numbers in sewage and is

thought to be a reliable indicator of sewage contamination of water. Monitoring for coliphage is an important

indicator for the survival and transport of viruses in the

environment. Viruses in drinking-water supplies have

an MCLG of zero (U.S. Environmental Protection

Agency, 1996).

Ground-water-monitoring wells also were

analyzed for MBAS, which can be an indicator of

nonpoint-source contamination by wastewater. The

MBAS analysis tests for the presence of anionic

sulfate- and sulfonate-based surfactants (Burkhardt

and others, 1995) that are present in soaps and detergents. Concentrations for MBAS ranged from less

than 0.02 to 0.12 mg/L with a median concentration of

0.03 mg/L. For 50 percent of the sites, MBAS concentrations were below the detection limit. The highest

concentration was at site G2 (0.12 mg/L), followed by

site G4 (0.08 mg/L). Sites G3 and G6 had concentrations at 0.03 mg/L, which is just above the detection

limit. The detection of MBAS in the ground water and

occurrence of bacteria and more elevated nutrients at

the same sites may indicate the possible contamination

by wastewater from septic systems or wastewatertreatment facilities.

In the Fraser River watershed, the limited

number of ground-water sites (a total of nine sites)

does not allow for a comprehensive analysis of the

water-quality conditions on a watershed scale. Characterization of the water-quality conditions over time

also cannot be effectively assessed with the available

ground-water-quality data.
28 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

Dating Analysis

Chlorofluorocarbon concentrations can be used

for dating young ground water (Plummer and others,

1993). CFC's, which are manmade and used as refrigerants, aerosol propellants, cleaning agents, solvents,

and blowing agents in the production of foam rubber

and plastics, were introduced into the atmosphere in

the 1940's and atmospheric concentrations have

increased through to the early 1990's. Ground water

acquires CFC's through recharge; with knowledge of

the temporal variations in the CFC concentrations in

the atmosphere, the age of the ground water can be

determined. Data for CFC's in the ground water are

available from the six monitoring wells installed in the

Fraser River watershed in 1996 (tables 2 and 5, fig. 5).

CFC data for site G1 were not obtainable because the

sample was contaminated with hydrocarbons. Sites G2

and G3 showed a similar age of the ground water from

early 1990's to late 1980's, respectively. At sites G4

and G6 the age of the ground water was mid-1970's or

younger. The CFC data for site G7 provides a groundwater age of early 1970's. Low dissolved oxygen, as

measured at some of the sites, may result in a falsely

old CFC age and also may result in degraded CFC's

such as at sites G4 and G6. The initial results from the

CFC data indicate that alluvial ground water is from

10 to 30 years old; that is, the water sample collected

from the alluvial ground water was introduced into the

aquifer as recharge from 10 to 30 years ago.

These dates indicate that changes in the land use

in recharge areas may not affect the alluvial groundwater quality for 10 to 30 years. Supplementing waterquality data with the age of the ground water is important in order to provide a better understanding of the

link between land use and the water quality in the

underlying aquifers. In cases where water may have to

travel over a long time and distance, the implementation of land-management practices may take many

years to produce improvement in the water quality. In

addition, the implementation of land-management

practices before development may help to reduce the

potential contamination from land-use practices.

Ground-water dating can be used in conjunction with

ground-water modeling to determine recharge areas

and ground-water flow paths, so that managers can

select strategies for maintaining or improving groundwater quality.

SURFACE WATER

Water Quantity

The major tributaries of the Fraser River include

Vasquez Creek, St. Louis Creek, Crooked Creek, Pole

Creek, Ranch Creek, Strawberry Creek, and Tenmile

Creek (fig. 1). Hydrologic modification in the upper

part of the Fraser River watershed affects the quality

and beneficial uses of the Fraser River (Colorado

Water Quality Control Division, 1989). Diversions at

the headwaters of the Fraser River watershed at St.

Louis and Vasquez Creeks reduce the flow and

adversely affect water quality through nonpoint-source

pollution. The Fraser River diversion system collects

and conveys water from the Fraser River, its tributaries, and flow from the Vasquez water tunnel into the

Moffat water tunnel.

For the Fraser River Valley the hydrologic characteristics can be represented in a generalized water

budget (table 6). Average annual water input for the

watershed is 392,200 acre-ft/yr, based on a weighted

average precipitation of 25.6 inches distributed over

the drainage area. The Fraser River watershed is a

headwater system and there are no surface-water

inflows to the basin except for small amounts of water

from transmountain diversions. Ground-water inflow

is assumed to be negligible. Water outputs from the

watershed are more diverse; the predominant output is

by evapotranspiration, which is calculated as the

residual in the water balance and accounts for about

58 percent of the total water output. Surface-water

outflow accounts for about 35 percent of the total

water output. Consumptive water use, estimated to be

7,500 acre-ft/yr based on 1995 water-use data,

accounts for less than 1 percent of the total water

output (R.G. Dash, U.S. Geological Survey, written

commun., 1998). Consumptive water use in the watershed is predominantly for irrigation. Transmountain

diversions account for about 6 percent of the outputs

for the watershed in 1995.

Streamflow measurements have been made at

12 gaging stations in the watershed, with 9 of the

gaging stations active through water year 1997

(table 3). About 70 percent of the annual streamflow is

derived from snowmelt and occurs in May, June, and

July. During most of the year the daily flow is less than

one-third of the mean annual streamflow, which

ranged from 3.14 to 218 ft3

/s among selected sites in
SURFACE WATER 29

Table 5. Chlorofluorocarbon data and calculated apparent ground-water recharge date for six monitoring wells sampled in the Fraser River watershed[no., number; cont., contaminated; indet., indeterminable; pg/kg, picograms per kilogram; pptv, parts per trillion by volume; CFC, chlorofluorocarbon]

Site no.

(fig. 5)

Site identification

number

(latitude-longitude)

Chlorofluorocarbon

concentration in water

(pg/kg)

Chlorofluorocarbon

partial pressure (pptv)

Chlorofluorocarbon

apparent CFC recharge date

Recharge

temperature

(degrees

Celsius)

Recharge

altitude

(feet)

Estimated

recharge

date

CFC-11 CFC-12 CFC-113 CFC-11 CFC-12 CFC-113 CFC-11 CFC-12 CFC-113

G1 395507105470200 479.5 648.5 67.3 184.8 1,118.1 60.9 1981.5 cont. 1987.5 6.3 8,780 indet.

182.8 1,207.4 113.4 70.5 2,082.7 102.7 1971.0 cont. cont. 6.3 8,780185.1 1,144.4 73.7 71.3 1,974.1 66.7 1971.0 cont. 1988.5 6.3 8,780

G2 395605106473100 329.8 307.0 131.9 124.3 519.0 116.6 1975.5 1993.0 cont. 6.0 8,660 1992

370.3 298.1 101.9 139.6 503.9 90.1 1976.5 1991.5 modern 6.0 8,660354.7 352.5 147.8 133.7 595.8 130.7 1976.0 cont. cont. 6.0 8,660

G3 395623105481000 1,436.8 427.7 81.8 515.5 691.8 68.5 cont. cont. 1988.5 5.2 8,620 1989

1,246.8 438.2 79.4 447.3 708.7 66.5 cont. cont. 1988.5 5.2 8,6201,417.5 447.2 85.1 508.6 723.3 71.3 cont. cont. 1989.0 5.2 8,620

G4 395648105485300 83.2 112.0 0.72 38.8 229.0 0.8 1967.0 1975.0 1956.0 9.8 8,570 1974

1,334.5 107.3 0.0 622.9 219.6 0.0 cont. 1974.5 1954.5 9.8 8,570

G6 395706105485000 21.3 48.5 0.0 7.7 78.6 0.0 1958.0 1966.0 1954.5 5.3 8,520 1967

30.5 55.1 0.0 11.0 89.3 0.0 1960.0 1967.0 1954.5 5.3 8,52037.0 66.6 0.0 13.3 107.8 0.0 1961.0 1968.5 1954.5 5.3 8,520

G7 395929105510300 120.8 97.3 7.84 44.2 159.9 6.7 1968.0 1971.5 1971.0 5.7 8,320 1972

110.5 97.5 9.74 40.4 160.2 8.3 1967.5 1971.5 1972.5 5.7 8,320121.2 107.6 12.7 44.3 176.7 10.9 1968.0 1972.5 1974.5 5.7 8,320
30 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

Table 6. Generalized water budget for the Fraser River watershed

[<, less than]

Source Inputs

(acre-feet per year) Percent Source Outputs(acre-feet per year) Percent

Precipitation (25.6 inches) 391,900 100 Evapotranspiration from

 nonirrigated land (residual)

225,700 58

Surface-water inflow negligible Surface-water outflow 135,500 a 35

Transmountain diversions

(Vasquez water tunnel)c 300 <1 Consumptive water use 7,500 b 0.02

Ground-water inflow negligible Transmountain diversions

(Moffat water tunnel)

23,500 c 6

Reservoir evaporation negligible

Ground-water outflow unknown

Change in ground-water storage negligible

Total (rounded) 392,200 100 Total (rounded) 392,200 100

a

 Data from the U.S. Geological Survey National Water Information System (site 67 in table 3) and Mark Leu,

Northern Colorado Water Conservancy District, written commun., 1998.

b

 Based on 1995 data (R.G. Dash, U.S. Geological Survey, written commun., 1998).

c

 Based on 1995 data (R.C. Steger, Denver Water Board, written commun., 1998).

Table 7. Hydrologic characteristics for selected surface-water stations in the Fraser River watershed

[mi2, square miles; ft3/s, cubic feet per second]

Site no.

(figs. 5

and 6)

Site name Station identification

number

Period of

record, in

water years

Drainage area

(mi2)

Mean annual

streamflow

(ft3/s)

Coefficient

of variation

of annual

streamflow

Mean

annual

runoff

(inches)

 3 Fraser River at Upper Station

near Winter Park, CO

09022000 1969–73

1984–97

10.5 14.4 0.16 18.5

16 Fraser River at Winter Park, CO 09024000 1910–34

1935–97

27.6

27.6

44.6

17.2

0.21

0.55

22.0

8.5

20 St. Louis Creek near Fraser, CO 09026500 1934–97 32.9 26.7 0.43 11.0

23 Elk Creek near Fraser, CO 09025400 1971–96 7.15 3.14 0.61 6.0

24 Vasquez Creek at Winter Park,

CO

09025000 1934–97 27.8 14.4 0.69 7.0

40 Ranch Creek near Fraser, CO 09032000 1935–97 19.9 14.5 0.55 9.9

48 Cabin Creek near Fraser, CO 09032100 1984–97 4.87 6.50 0.38 18.1

67 Fraser River at Granby, CO 09034000 1904–09

1937–55

297

297

218

148

0.27

0.35

10.0

6.8
SURFACE WATER 31

the watershed (table 7). Mean annual runoff ranges

from 6.0 to 22.0 inches and reflects the high amounts

of precipitation in the watershed. Coefficient of variation, which is a measure of the variability of streamflow from year to year, ranges from about 0.16 to 0.69.

As a result of the variability of the timing and magnitude of the streamflow from year to year, water quality

can be affected. The removal of water from water

diversions at the headwaters of the Fraser River also

can affect the water quality.

Annual mean streamflow varies at four selected

stations (fig. 10). Streamflow at the Fraser River at

Upper Station near Winter Park (site 3, table 7) is

unaffected by transmountain diversions, and the variability in the streamflow is low (coefficient of variance

of 0.16). Fraser River at Winter Park (site 16, table 7),

which has the longest period of record, is affected by

transmountain diversions, and the coefficient of variance ranges from 0.21 prior to 1935 to 0.55 after 1935.

In 1936 the first part of the Fraser River diversions,

which divert water through the Moffat water tunnel,

was completed. Streamflow at St. Louis Creek (site 20,

fig. 10) and Vasquez Creek (site 24, fig. 10) is similar

to the Fraser River at Winter Park station (site 16,

fig. 10). Mean monthly flows for the four stations are

similar, indicating that streamflow is dominated by

snowmelt (fig. 11).

Water Quality

Water-quality property and constituent data

available for the surface-water sites consist of field

parameters (water temperature, specific conductance,

dissolved oxygen, pH, and alkalinity), inorganic

species (primarily chloride, some trace elements, and

nutrients), and bacteria (table 8). The distribution of

selected water-quality data for all surface-water sites

(table 3 and fig. 12) are classified by land use (forest,

rangeland, and urban). The pH values ranged from 5.5

to 9.9 with the highest median value of 7.9 associated

with the urban land use. A few pH values were below

(about 0.1 percent; 2 of 1,505) and above (about

0.3 percent; 4 of 1,505) the recommended stream

water-quality standards for pH (6.5–9.0). Specific

conductance ranged from 7 to 1,650 μS/cm, and the

highest median concentration was associated with

rangeland (90 μS/cm). The most frequently analyzed

major ion was chloride, with concentrations ranging

from less than 0.1 to 47 mg/L, and forested lands had

the highest median concentration (6.6 mg/L). Chloride

concentrations were below the stream-water-quality

standards of 250 mg/L (Colorado Water Quality

Control Commission, 1996). Dissolved manganese,

which had fewer analyses than chloride, ranged in

concentration from less than 4 to 55 μg/L, and the

highest median concentration was associated with

rangeland (35 μg/L). Only one analysis (about

2 percent; 1 of 53) for dissolved manganese exceeded

the stream-water-quality standard of 50 μg/L (Colorado Water Quality Control Commission, 1996). Sedimentary rocks underlie rangeland in the watershed and

may be the primary source of the manganese.

Distributions of the nutrient concentrations are

represented in boxplots for ammonia, nitrite, nitrate,

orthophosphate, and total phosphorus by landuse/land-cover classification (fig. 13). The majority of

the surface-water-quality data are available for urban

land use. In comparing ammonia concentrations

among forest, rangeland, and urban land uses, the

highest ammonia concentrations were associated with

the urban land, which had a median concentration of

0.11 mg/L. Ammonia concentrations in the Fraser

River watershed were higher in the urban setting than

ammonia concentrations (median concentrations were

less than 0.10 mg/L) from sites sampled in the Upper

Colorado River Basin (Spahr and Wynn, 1997).

Criteria exist for un-ionized ammonia concentrations

based upon the chronic and acute exposure of an

aquatic organism to un-ionized ammonia (Colorado

Water Quality Control Commission, 1996). These

criteria vary, depending on the pH and temperature of

the water at the time of sampling. The criteria and

stream concentrations for dissolved ammonia can be

calculated for pH values ranging from 6.5 to 9.0 and

temperatures ranging from 0 to 30o

C. The Colorado

Water Quality Control Commission has established a

chronic criterion for un-ionized ammonia of

0.02 mg/L for the Fraser River. The un-ionized

ammonia chronic criterion for cold-water biota was

exceeded in one sample at site 43 and in one sample at

site 49 (table 3 and fig. 5).

Nitrite concentrations for all land uses ranged

from less than 0.001 to 0.4 mg/L, and the urban sites

had the highest median nitrite concentration

(0.005 mg/L). Nitrate concentrations ranged from

0.003 to 12.6 mg/L. In the Fraser River watershed only

two analyses, which were associated with the urban

land use, had nitrate concentrations that exceeded the
32 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

Fraser River at Upper Station near Winter Park, Colorado

(Site 3; 1969-97)

Fraser River at Winter Park, Colorado

(Site 16; 1910-97)

St. Louis Creek near Fraser, Colorado

(Site 20; 1934-97)

Vasquez Creek at Winter Park, Colorado

(Site 24; 1934-97)

1900 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

1900 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

1900 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

1900 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

70

0

60

50

40

30

20

10

60

50

40

30

20

10

45

40

35

30

25

20

15

10

0

0

25

20

15

10

5

5

0

WATER YEAR

ANNUAL MEAN STREAMFLOW, IN CUBIC FEET PER SECOND

Figure 10. Annual mean streamflow at selected surface-water stations in the Fraser River watershed.
SURFACE WATER 33

Fraser River at Upper Station near Winter Park, Colorado

(Site 3; 1969-97)

Fraser River at Winter Park, Colorado

(Site 16; 1910-97)

St. Louis Creek near Fraser, Colorado

(Site 20; 1934-97)

Vasquez Creek at Winter Park, Colorado

(Site 24; 1934-97)

Jan Feb Mar April May June July Aug Sept Oct Nov Dec

Jan Feb Mar April May June July Aug Sept Oct Nov Dec

Jan Feb Mar April May June July Aug Sept Oct Nov Dec

Jan Feb Mar April May June July Aug Sept Oct Nov Dec

80

70

60

50

40

30

20

10

0

140

120

100

80

60

40

20

0

140

120

100

80

60

40

20

0

80

70

60

50

40

30

20

10

0

MONTH

MEAN MONTHLY STREAMFLOW, IN CUBIC FEET PER SECOND

Figure 11. Mean monthly streamflow at selected surface-water stations in the Fraser River watershed.
34 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

Table 8. Summary of the minimum, median, and maximum values for the surface-water-quality properties and constituents for

all sites sampled in the Fraser River watershed

[---, no data; <, less than; μS/cm, microsiemens per centimeter; mg/L, milligrams per liter; μg/L, micrograms per liter; cols/100 mL, colonies per 100 milliliters; TVS, table value standard; ac, acute standard; ch, chronic standard]

Properties, constituents, and

reporting units

Number

of analyses

Number

of censored

analyses

Minimum Median Maximum Stream-segment

standards1

Water temperature (degrees Celsius) 2,951 0 0.0 4.0 19.5 ---

Specific conductance, field (μS/cm) 2,584 0 7.0 75.0 1,650 ---

Dissolved solids (mg/L) 17 0 44.0 68.0 106 ---

Hardness, total (mg/L as CaCO3) 102 0 8.0 46.0 140 ---

Oxygen, dissolved (mg/L) 1,167 0 0.2 9.9 16.4 6.0-7.0

pH, field (standard units) 1,505 0 5.5 7.8 9.9 6.5-9.0

Alkalinity, field (mg/L as CaCO3) 103 0 12.0 48.0 140 ---

Major ions

Calcium, dissolved (mg/L) 17 0 6.6 8.9 19.0 ---

Chloride, dissolved (mg/L) 199 6 <0.1 5.5 47 250

Fluoride, total (mg/L) 84 0 24.0 365 2,900 ---

Magnesium, dissolved (mg/L) 19 0 0.2 2.8 5.1 ---

Potassium, dissolved (mg/L) 17 0 0.6 1.2 3.0 ---

Sodium, dissolved (mg/L) 17 0 2.4 6.1 18.0 ---

Silica, dissolved (mg/L) 17 0 6.6 10.0 15.0 ---

Sulfate, dissolved (mg/L) 120 64 <5.0 <5.0 12.0 250

Nutrients

Ammonia (mg/L) 495 101 <0.002 0.026 26.0 TVS

Nitrite (mg/L) 441 70 <0.001 0.004 0.40 0.005

Nitrate (mg/L) 432 0 0.003 0.087 12.6 10

Orthophosphate (mg/L) 156 31 <0.001 0.006 0.19 ---

Total phosphorus (mg/L) 95 9 <0.01 0.06 0.33 ---

---

Trace elements

Arsenic, dissolved (μg/L) 19 16 <1.0 <1.0 5.0 ---

Arsenic, total (μg/L) 3 0 1.0 1.0 1.0 50 (ac)

Boron, total (μg/L) 12 7 <12.0 <12.0 120 ---

Cadmium, dissolved (μg/L) 47 29 <0.25 <0.25 3.0 TVS

Cadmium, total recoverable (μg/L) 4 0 1.0 1.0 3.0 TVS

Copper, dissolved (μg/L) 43 39 <4.0 <4.0 6.0 TVS

Copper, total recoverable (μg/L) 3 0 8.0 8.0 11.0 ---

Iron, dissolved (mg/L) 33 0 20.0 180 450 300 (ch)

Lead, dissolved (μg/L) 33 29 <1.0 <1.0 4.0 TVS

Lead, total recoverable (μg/L) 3 0 1.0 5.0 7.0 ---

Manganese, dissolved (μg/L) 53 7 <4.0 19.0 55.0 50 (ch)

Manganese, total recoverable (μg/L) 7 0 5.0 40.0 80 1,000 (ch)

Mercury, dissolved (μg/L) 33 33 <0.2 <0.2 <0.2 ---

Mercury, total recoverable (μg/L) 26 25 <0.5 <0.5 0.5 0.01(ch)

Molybdenum, total recoverable (μg/L) 4 0 27.0 29.5 32.0 ---

Selenium, dissolved (μg/L) 15 15 <1.0 <1.0 <1.0 ---
SURFACE WATER 35

Properties, constituents, and

reporting units

Number

of analyses

Number

of censored

analyses

Minimum Median Maximum Stream-segment

standards1

Trace elements—Continued

Selenium, total (μg/L) 8 5 <2.0 <2.0 5.0 ---

Silver, dissolved (μg/L) 17 17 <0.2 <0.2 <0.2 TVS

Uranium, dissolved (μg/L) 6 0 1.5 2.5 4.0 ---

Zinc, dissolved (μg/L) 45 26 <8.0 <8.0 100 TVS

Zinc, total recoverable (μg/L) 49 30 <10.0 <10.0 400 ---

Other constituents

Sediment concentration (mg/L) 606 15 <0.001 1.81 164 ---

Total coliforms (cols/100 mL) 20 5 <1 59.5 86,000 ---

Fecal coliforms (cols/100 mL) 329 55 <1 1 78,000 2,000

Fecal streptococcus (cols/100 mL) 18 10 <1 9.5 840 ---

1

 Stream-segment standards from Colorado Water Quality Control Commission, 1996.

Table 8. Summary of the minimum, median, and maximum values for the surface-water-quality properties and constituents for

all sites sampled in the Fraser River watershed—Continued

[---, no data; <, less than; μS/cm, microsiemens per centimeter; mg/L, milligrams per liter; μg/L, micrograms per liter; cols/100 mL, colonies per 100 milliliters; TVS, table value standard; ac, acute standard; ch, chronic standard]

USEPA 10-mg/L MCL criterion for nitrate in drinking

water (U.S. Environmental Protection Agency, 1996).

The urban land-use setting had the highest median

nitrate concentration of 0.14 mg/L. Orthophosphate

for the urban land-use classification had a higher

median concentration (0.021 mg/L) than the median

concentration for forest (0.001 mg/L). No national

criteria have been established for phosphorus concentration in stream water. However, to control eutrophication, the USEPA recommends that total phosphorus

concentrations should not exceed 0.1 mg/L for flowing

waters that do not discharge directly into a lake or

reservoir (U.S. Environmental Protection Agency,

1986). Total phosphorus concentrations that exceeded

0.1 mg/L were detected for about 23 percent of the

analyses (22 of the 95 analyses). Concentrations that

exceeded 0.1 mg/L were detected in all land-use/landcover classifications from the available data, with

median concentrations for rangeland and urban land

uses being similar (about 0.07 mg/L). Higher concentrations of total phosphorus can result in increased

algae in the streams, which can be undesirable esthetically.

Thirty surface-water sites, predominantly those

associated with forest land-use classification, have

been monitored for bacteria in the watershed. Microbial sampling has been completed for total coliform,

fecal coliform, and fecal streptococcus. Most of the

sampling (about 83 percent; 303 of 367 samples)

occurred between 1974 and 1989. The most recent

sampling from 1990 to 1997 accounts for the other

17 percent of the bacteria sampling in the watershed.

Total coliform bacteria were measured 20 times from

1974 to 1981 with values ranging from less than 1 to

86,000 cols/100 mL; a median value for these

20 samples was about 60 cols/100 mL. Total coliform

bacteria in fecal-contaminated surface water ranged

from 1,200 to 4,000,000 cols/100 mL (Meyers and

Sylvester, 1997). For the samples collected for total

coliform, the largest number of bacteria colonies were

associated with urban land use.

For the main stem of the Fraser River and its

tributaries, the established stream-segment standard

for fecal coliform is 2,000 cols/100 mL. In all,

329 analyses for fecal coliform bacteria were

completed at sites on the Fraser River with concentrations ranging from less than 1 to 78,000 cols/100 mL;

however, only two analyses at site 72 exceeded the

standard of 2,000 cols/100 mL. These samples were

collected in 1974 and 1983. In the watershed,

18 analyses (1976–81) were available for fecal streptococcus. Concentrations ranged from less than 1 to

840 cols/100 mL, and the median value was about

10 cols/100 mL. Fecal-contaminated surface water

analyzed for fecal streptococcus generally ranged

from 400 to more than 1,000,000 cols/100 mL

(Meyers and Sylvester, 1997). Surface-water sites
36 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

EXPLANATION

Number of samples

Data values outside the 

 10th and 90th percentiles

Data values 

Percentiles

Figure 12. Distribution of (a) pH, (b) specific conductance, (c) chloride, and (d) manganese by land-use/land-cover classifications for all surface-water sites.
SURFACE WATER 37

e

EXPLANATION

Number of samples

Data values outside the 

 10th and 90th percentiles

Percentiles

Detection limit (DL)

Figure 13. Distribution of (a) ammonia, (b) nitrite, (c) nitrate, (d) orthophosphate, and (e) total phosphorus by land-use/landcover classifications for all surface-water sites.
38 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

sampled for bacteria in the 1990's had concentrations

less than the established stream-segment standards.

Surface-water-quality data are limited in the

watershed and provide only a general assessment of

the water-quality conditions. For instance, additional

water-quality data for the mouth of the Fraser River

would provide a better understanding of the variation

in chemical constituents for the Fraser River watershed. Currently, water-quality data are not being

collected to assess water-quality conditions in the

entire watershed since the water-quality-sampling site

near the mouth of the Fraser River (site 63) was

discontinued in water year 1992.

SPATIAL DISTRIBUTION OF CONCENTRATIONS

Spatial distribution of the median concentrations for specific conductance and nutrient species

(ammonia, nitrite, nitrate, and total phosphorus) is

shown in figures 14–18. Surface-water sites with more

than five analyses are represented in these figures.

Concentration intervals in the figures represent

concentrations less than the 25th percentile, concentrations between the 25th and 50th percentiles, concentrations between the 50th and 75th percentiles, and

concentrations greater than the 75th percentile.

Specific conductance in the Fraser River watershed increases in a downstream direction (fig. 14),

probably because of changes in the geology; crystalline rocks are in the headwaters and sedimentary rocks

are in the downstream valleys. However, specificconductance values for the Fraser River watershed are

relatively low (median concentrations of 75.0 μS/cm)

when compared to the median concentration

(254 μS/cm) for surface-water sites sampled in the

Upper Colorado River Basin, Southern Rocky Mountains physiographic province, as part of the UCOL

NAWQA Program.

The available nutrient data allow for only a

general assessment of the spatial distribution for select

nutrient concentrations in the watershed (figs. 15–18).

In general, nutrient concentrations increase in the

vicinity of urban centers. Sites located upstream from

Winter Park on the Fraser River and upstream on

St. Louis Creek have the lowest nutrient concentrations. Ammonia concentrations for the watershed

overall are higher than the median ammonia concentration of 0.04 mg/L determined for urban sites in the

basinwide assessment of nutrient species in the Upper

Colorado River Basin (Spahr and Wynn, 1997). Nitrite

concentrations in the watershed were low, with a

median concentration of 0.004 mg/L. A median nitrate

concentration of 0.3 mg/L was determined for urban

sites in the Upper Colorado River Basin (Spahr and

Wynn, 1997), and only one site in the Fraser River

watershed had a concentration close to 0.3 mg/L in the

urban setting. Nitrate concentrations were less than

0.3 mg/L at all other urban sites. Total phosphorus for

urban sites in the Upper Colorado River Basin had a

median concentration of 0.04 mg/L (Spahr and Wynn,

1997). In the Fraser River watershed concentrations

were above this median value at one-half of the sites,

and the other sites associated with urban development

were comparable to the median value.

Only four sites in the watershed had sufficient

data to plot concentration as a function of time

(fig. 19). Overall, the ammonia concentrations appear

to decrease from 1990 to 1997 for all sites. The

highest ammonia concentrations were detected in

1990 and 1991. The principal change in the ammonia

values appears to be the reduction in the higher winter

concentrations. This could be due to changes in regulations because wastewater-treatment-plant operators

change plant operations to comply with required

limits. Total phosphorus concentrations appear fairly

consistent over time, with no obvious changes in the

phosphorus concentrations.

TEMPORAL TRENDS IN NUTRIENT SPECIES

CONCENTRATIONS

Results of the trend analysis of nutrient species

using the seasonal Kendall test (Helsel and Hirsch,

1992) are shown in table 9. For significant trends

(p-values less than 0.05), the slope in units per year is

indicated in this table. Ranges in slopes are given for

sites with censored data, and the different slopes are

computed with the censored data equal to the censored

value and equal to zero. The true slope of the trend line

would be in the range of these values. Analysis of

temporal trends was completed for four sites in the

watershed having sufficient data to meet the statistical

requirements as outlined in the "Methods of Data

Review and Analysis" section of this report. The

sampling period varied between these sites but is

comparable for three of the four sites with similar

periods of records and common nutrient species.

Trend analysis is useful in determining if

concentrations for selected constituents have changed
SURFACE WATER 39

Granby

EXPLANATION

Specific conductance, in

microsiemens per centimeter

(with site number)

Greater than 95

74 to 95

52 to 74

Less than 52

Tabernash

Fraser

Winter Park

Figure 14. Spatial distribution of median concentrations for specific conductance.
40 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

Granby

EXPLANATION

Ammonia, in

milligrams per liter

(with site number)

Greater than 0.188

0.018 to 0.188

0.003 to 0.018

Less than 0.003

Tabernash

Fraser

Winter Park

Figure 15. Spatial distribution of median concentrations for ammonia.
SURFACE WATER 41

Tabernash

Fraser

Granby

EXPLANATION

Nitrite, in

milligrams per liter

(with site number)

Greater than 0.007

0.003 to 0.007

0.001 to 0.003

Less than 0.001

Winter Park

Figure 16. Spatial distribution of median concentrations for nitrite.
42 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

Tabernash

Fraser

Granby

EXPLANATION

Nitrate, in

milligrams per liter

(with site number)

Greater than 0.215

0.083 to 0.215

0.043 to 0.083

Less than 0.043

Winter Park

Figure 17. Spatial distribution of median concentrations for nitrate.
SURFACE WATER 43

Tabernash

Winter

Fraser

Granby

Park

EXPLANATION

Total phosphorus, in

milligrams per liter

(with site number)

Greater than 0.091

0.070 to 0.091

0.028 to 0.070

Less than 0.028

Figure 18. Spatial distribution of median concentrations for total phosphorus.
44 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

Fraser River below Buck Creek at Winter Park, Colorado

(Station 09023750; Site 11)

Fraser River below Vasquez Creek at Winter Park, Colorado

(Station 09025010; Site 28)

Fraser River at Tabernash, Colorado

(Station 09027100; Site 49)

Upper Colorado River, Fraser River near Granby, Colorado

(Station 400454105554201; Site 63)

5/7/90 5/7/91 5/6/92 5/6/93 5/6/94 5/6/95 5/5/96 5/5/97

0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

1.8

1.6

1.4

1.2

1

0.8

0.6

0.4

0.2

5/7/90 5/7/91 5/6/92 5/6/93 5/6/94 5/6/95 5/5/96 5/5/97

0

5/7/90 5/7/91 5/6/92 5/6/93 5/6/94 5/6/95 5/5/96 5/5/97

0

0.35

0.3

0.25

0.2

0.15

0.1

0.05

12/11/78 12/11/79 12/10/80 12/10/81 12/10/82 12/10/83 12/9/84 12/9/85

DATE

12/9/86 12/9/87 12/8/88 12/8/89 12/8/90 12/8/91 12/7/92

0

0.02

0.04

0.06

0.08

0.1

0.12

Figure 19. Temporal variations in ammonia and total phosphorus concentrations for selected sites in the Fraser River

watershed.
SURFACE WATER 45

Table 9. Results of the seasonal Kendall test for trends of selected nutrient species in the Fraser River watershed[no., number; units/yr, units per year; mg/L, milligrams per liter; <, less than; ---, no data]

Site no.

(figs. 5

and 6)

Site name Number of analyses Number of censored analyses Censored value Trend direction p-value of tau test Slope (units/yr) Median concentration (mg/L)

Ammonia, as nitrogen

(water years 1991–96)

11 Fraser River below Buck Creek at

Winter Park, CO

60 22 <0.002 down <0.0001 –0.002 to –0.0029 0.006

28 Fraser River below Vasquez Creek

at Winter Park, CO

72 12 <0.002 down 0.0040 –0.0044 to –0.005 0.025

49 Fraser River at Tabernash, CO 72 8 <0.002 down 0.0004 –0.0065 to –0.0068 0.042

Nitrite, as nitrogen (water years 1991–96)

11 Fraser River below Buck Creek at

Winter Park, CO

59 15 <0.001 down 0.0333 –0.0003 to –0.0008 0.002

28 Fraser River below Vasquez Creek

at Winter Park, CO

70 8 <0.001 down 0.0026 –0.001 to –0.0008 0.004

49 Fraser River at Tabernash, CO 70 4 <0.001 down <0.0001 –0.0017 0.006

Nitrate, as nitrogen (water years 1991–96)

11 Fraser River below Buck Creek at

Winter Park, CO

58 0 none none 0.9433 --- 0.07

28 Fraser River below Vasquez Creek

at Winter Park, CO

71 0 none none 0.0815 --- 0.088

49 Fraser River at Tabernash, CO 71 0 none down <0.0001 –0.0107 0.134

Total phosphorus (water years 1980–91, quarterly sampling)

63 Upper Colorado River, Fraser River

near Granby, CO

63 29 <0.05 none 0.6687 --- 0.055
46 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

over time. However, a trend may not be statistically

significant if the rate of change (slope) is small for the

trend line or if the constituents are very low in concentration. Downward trends were observed for ammonia

and nitrite for sites 11, 28, and 49 (table 9). Nitrate

showed no trend except for site 49, which showed a

downward trend. No trend was observed for total

phosphorus at site 63. The downward trends in the

nutrient species probably reflect changes in wastewater-treatment facilities in the watershed.

In evaluating the median concentrations determined from the trend analysis, it is important to

compare these results with other data from similar

areas. Spahr and Wynn (1997) summarized the water

quality in surface water of the Upper Colorado River

Basin in relation to nitrogen and phosphorus species.

They compared the median nutrient concentrations to

different land uses in the basin. For ammonia as

nitrogen, Spahr and Wynn (1997) determined concentrations of 0.02 mg/L for background sites and

0.04 mg/L for urban sites. From their study, the

median nitrate as nitrogen concentrations for undeveloped and urban sites were 0.09 and 0.3 mg/L, respectively, and the median concentrations for total

phosphorus at undeveloped and urban sites were 0.03

and 0.04 mg/L, respectively. Median concentrations,

as determined for the water years used in the trend

analysis, generally indicate that the surface-water

quality at sites 49 and 63 is affected by land use.

SUMMARY

In order to evaluate the available water quantity

and quality through water year 1997 of the groundwater and surface-water resources in the Fraser River

watershed, data were obtained from Federal, State, and

local agencies. The predominant sources of information were the U.S. Geological Survey National Water

Information System (NWIS) and the U.S. Environmental Protection Agency Storage and Retrieval

(STORET) data bases. Water quantity or quality data,

or both, were collected at a total of 81 sites (9 ground

water and 72 surface water) at various times from

1904 to 1997.

The Fraser River watershed has a drainage area

of 287 mi2

 with its headwaters at the Continental

Divide. The watershed is located at altitudes ranging

from 8,000 to 12,800 ft and can receive more than

40 inches per year of precipitation along the Continental Divide. Ground-water resources are available

for residential and municipal use. The alluvial and

Troublesome Formation aquifers yield water more

readily than other aquifers in the watershed. Surfacewater resources in the area include the Fraser River

and its tributaries. The major land use/land cover in

the watershed is forested land; however, increasing

urban development in the watershed has the potential

to affect the water quantity and water quality of the

resources.

From the limited water-level data, it can be

stated that ground-water flow directions for the alluvial and Troublesome Formation aquifers generally

follow topography upstream from Tabernash. Available ground-water-use information indicates yields for

the alluvial aquifer of about 100 gallons per minute

and for the Troublesome Formation aquifer of about

110 to 220 gallons per minute. However, additional

information is needed to better estimate ground-water

reserves for these aquifers, which may range from 1.6

to 2.7 million acre-feet.

Ground-water-quality data from nine sites

generally consisted of field parameters, major ions,

nutrients, trace elements, radon, dissolved organic

carbon, pesticides, volatile organic compounds,

bacteria, and methylene blue active substances. In

addition, shallow ground water was dated at six sites

using chlorofluorocarbons (CFC’s). In general,

concentrations of water-quality constituents were less

than U.S. Environmental Protection Agency (USEPA)

drinking-water standards. However, iron and manganese concentrations in the shallow alluvial aquifer

exceeded the USEPA secondary maximum contaminant level (SMCL) for drinking water. High concentrations of these two elements also were detected in the

Middle Park Formation.

Concentrations of radon exceeded the USEPA

proposed MCL for radon (which is currently being

revised) at eight of the ground-water sites. The radon

concentrations are derived from natural sources; in

areas where the decay of uranium occurs, radon

concentrations would be elevated. Uranium-bearing

minerals are found in association with Precambrian

rocks, which are present in the Fraser River watershed.

No pesticides were detected in the ground water.

However, land-use effects on the shallow groundwater quality were indicated by the detection of volatile organic compounds (VOC’s) at two alluvial monitoring wells. Although the concentrations did not

violate drinking-water standards or advisories, it is
SUMMARY 47

evident that the ground-water quality is vulnerable to

land-use effects.

Microbial sampling also was completed for

eight wells in the watershed. Total coliform and

coliphage were detected in three samples in the watershed. The detection of bacteria and viruses indicates a

concern for public health, if the water were to be used

as a drinking supply. Methylene blue active

substances (MBAS) also were analyzed and detected

at four sites. The detection of MBAS, bacteria, and

more elevated nutrients at the same sites may indicate

the possible contamination by wastewater from septic

systems or wastewater-treatment facilities.

Age of the alluvial ground water in the Fraser

River watershed ranged from about 10 to 30 years.

The age indicates that effects of land-use activities

may take some time to affect the ground-water

quality. Likewise, if a water-quality problem exists,

results of land-management practices to improve

water quality might not be apparent for many years.

For the Fraser River watershed, water input into

the watershed is mainly from precipitation. Outputs

from the watershed, in order of decreasing volume,

include evapotranspiration, runoff, water diversions,

and consumptive use. Streamflow in the watershed is

dominated by snowmelt, and 70 percent of the flow

occurs in May, June, and July. Coefficient of variation

of the annual mean streamflows (ranging from 0.16 to

0.69) is largest for sites affected by transmountain

diversions.

Surface-water-quality data for the Fraser River

watershed were limited. In general, concentrations of

surface-water-quality constituents were less than

stream-segment standards. However, the available

water-quality data indicate that elevated concentrations of selected constituents generally are related to

specific land uses. For the surface-water sites only

one sample exceeded the USEPA SMCL for manganese. Two samples from two surface-water sites in the

watershed exceeded the un-ionized ammonia chronic

criterion.

Nutrient species represent the most abundant

data for examining the spatial and temporal variability and trends in the water quality. The effects of

land use are apparent in the watershed as stream sites

in the area associated with urban development have

the highest median concentration of nutrient species.

Spatial distribution of nutrient species (ammonia,

nitrite, nitrate, and total phosphorus) shows that

elevated concentrations occur primarily downstream

from urban areas. Bacteria sampling completed in the

watershed also indicates that the occurrence of

bacteria in the water is related to urban land use.

Data at four surface-water sites were analyzed

for temporal trends in nutrient concentrations. Downward trends were identified for ammonia and nitrite

for three sites. Nitrate for two sites showed no trends,

and one site showed a downward trend. The only site

with total phosphorus data showed no trend. The

downward trend in the nutrient species probably

reflects changes in the wastewater-treatment facilities

in the watershed.

Limited ground-water and surface-water data

provide a general assessment of the water-quantity

and water-quality resources of the Fraser River watershed. However, the available information indicates

where concentrations of water-quality constituents

historically and presently are less than or exceed

water-quality standards in the watershed, which is

important when devising watershed-management

strategies. Concentrations of constituents in groundand surface-water samples from the watershed generally are less than water-quality standards; however,

manganese and iron exceeded the USEPA SMCL in

the shallow ground-water sites and in one surfacewater sample. The detection of bacteria in the ground

and surface water and VOC's in the ground water is

an indication that land use probably is affecting the

water quality. Increased concentrations of nutrients in

the surface water downstream from urban centers are

another indication that urban land use in the watershed probably is affecting the water quality.
48 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

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APPENDIX
APPENDIX 53

Appendix I. List of properties and constituents for ground-water-quality data in the Fraser

River watershed

[USGS, U.S. Geological Survey; NWIS, National Water Information System; na, not applicable; μS/cm, microsiemens per centimeter; mg/L, milligrams per liter; μg/L, micrograms per liter; NTU, nephelometric turbidity units;

pCi/L, picocuries per liter; cols/100 mL, colonies per 100 milliliters; pfu, plaque-forming unit; *, pesticides analyzed in only the monitoring wells]

Constituent USGS NWIS parameter

code Reporting limit

FIELD PARAMETERS

Water temperature (degrees Celsius) 00010 na

Specific conductance (μS/cm) 00095 na

Oxygen, dissolved (mg/L) 00300 na

pH, field (standard units) 00400 na

Alkalinity, lab (mg/L as CaCO3) 90410 na

Alkalinity, field (mg/L as CaCO3) 39086 na

Turbidity (NTU) 00076 na

INORGANICS

Hardness total (mg/L as CaCO3) 00900 computed

Dissolved solids (mg/L) 70300 computed

Major ions, in milligrams per liter

Sample filtered through 0.45-micron filter

Bicarbonate (mg/L as HCO3) 00453 na

Calcium 00915 0.02

Chloride 00940 0.1

Fluoride 00950 0.1

Magnesium 00925 0.01

Potassium 00935 0.1

Silica 00955 0.01

Sodium 00930 0.2

Sulfate 00945 0.1

Nutrients, in milligrams per liter

Sample filtered through 0.45-micron filter

Ammonia, as N 00608 0.01

Nitrite, as N 00613 0.01

Nitrate, as N 00631 0.05

Orthophosphate, as P 00671 0.01

Trace elements, in micrograms per liter

Sample filtered through 0.45-micron filter

Aluminum 01106 1.0

Antimony 01095 1.0

Arsenic 01000 1.0

Barium 01005 1.0

Beryllium 01010 1.0

Boron 01020 16.0

Cadmium 01025 1.0

Chromium 01030 1.0
54 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

Constituent USGS NWIS parameter

code Reporting limit

Trace elements, in micrograms per liter

Sample filtered through 0.45-micron filter–Continued

Cobalt 01035 1.0

Copper 01040 1.0

Iron 01046 3.0

Lead 01049 1.0

Manganese 01056 1.0

Molybdenum 01060 1.0

Nickel 01065 1.0

Selenium 01145 1.0

Silver 01075 1.0

Uranium 22703 1.0

Zinc 01090 1.0

Radionuclides, in pCi/L

Radon-222 82303 26

ORGANICS

Dissolved organic carbon 00681 0.1 mg/L

Pesticides, in micrograms per liter

Sample filtered through 0.7-micron filter

*2,4,5-T 39742 0.035

*2,4-D 39732 0.15

*2,4-DB 38746 0.24

*2-(2,4,5-Trichlorophenoxy)

 propionic acid

39762 0.021

2,6-Diethylaniline 82660 0.003

*3-Hydroxycarbofuran 49308 0.014

*4,6-Dinitro-2-methylphenol 49299 0.42

Acetochlor 49260 0.002

*Acifluorfen 49315 0.035

Alachlor 46342 0.002

*Aldicarb 49312 0.55

*Aldicarb sulfone 49313 0.10

*Aldicarb sulfoxide 49314 0.021

Atrazine 39632 0.001

Azinphos, methyl- 82686 0.001

Benfluralin 82673 0.002

*Bentazon 38711 0.014

*Bromacil 04029 0.035

*Bromoxynil 49311 0.035

Appendix I. List of properties and constituents for ground-water-quality data in the Fraser

River watershed—Continued

[USGS, U.S. Geological Survey; NWIS, National Water Information System; na, not applicable; μS/cm, microsiemens per centimeter; mg/L, milligrams per liter; μg/L, micrograms per liter; NTU, nephelometric turbidity units;

pCi/L, picocuries per liter; cols/100 mL, colonies per 100 milliliters; pfu, plaque-forming unit; *, pesticides analyzed in only the monitoring wells]
APPENDIX 55

Constituent USGS NWIS parameter

code Reporting limit

Pesticides, in micrograms per liter

Sample filtered through 0.7-micron filter–Continued

Butylate 04028 0.002

Carbaryl 82680 0.003

*Carbaryl 49310 0.008

Carbofuran 82674 0.003

*Carbofuran 49309 0.12

*Chloramben 49307 0.42

Chloropyrifos 38933 0.004

*Chlorothalonil 49306 0.48

*Clopyralid 49305 0.23

Cyanazine 04041 0.004

DCPA (Dacthal) 82682 0.002

*Dacthal monoacid 49304 0.017

Deethylatrazine 04040 0.002

DDE, p,p'- 34653 0.006

Diazinon 39572 0.002

*Dicamba 38442 0.035

*Dichlobenil 49303 1.2

*Dichloroprop 49302 0.032

Dieldrin 39381 0.001

*Dinoseb 49301 0.035

Disulfoton 82677 0.017

*Diuron 49300 0.020

EPTC (Eptam) 82668 0.002

Ethalfluralin 82663 0.004

Ethoprophos 82672 0.003

*Fenuron 49297 0.013

*Fluometuron 38811 0.035

Fonofos 04095 0.003

HCH, alpha- 34253 0.002

Lindane 39341 0.004

Linuron 82666 0.002

*Linuron 38478 0.018

Malathion 39532 0.005

*MCPA 38482 0.17

*MCPB 38487 0.14

*Methiocarb 38501 0.026

Metolachlor 39415 0.002

*Methomyl 49296 0.017

Metribuzin 82630 0.004

Molinate 82671 0.004

Appendix I. List of properties and constituents for ground-water-quality data in the Fraser

River watershed—Continued

[USGS, U.S. Geological Survey; NWIS, National Water Information System; na, not applicable; μS/cm, microsiemens per centimeter; mg/L, milligrams per liter; μg/L, micrograms per liter; NTU, nephelometric turbidity units;

pCi/L, picocuries per liter; cols/100 mL, colonies per 100 milliliters; pfu, plaque-forming unit; *, pesticides analyzed in only the monitoring wells]
56 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

Constituent USGS NWIS parameter

code Reporting limit

Pesticides, in micrograms per liter

Sample filtered through 0.7-micron filter–Continued

Napropamide 82684 0.003

*Neburon 49294 0.015

*Norflurazon 49293 0.024

*Oryzalin 49292 0.31

*Oxamyl 38866 0.018

Parathion 39542 0.004

Parathion, methyl- 82667 0.006

Pebulate 82669 0.004

Pendimethalin 82683 0.004

Permethrin-cis 82687 0.005

Phorate 82664 0.002

*Picloram 49291 0.05

Prometon 04037 0.018

Propachlor 04024 0.007

Propanil 82679 0.004

Propargite 82685 0.013

*Propham 49236 0.035

*Propoxur 38538 0.035

Propyzamide 82676 0.003

Simazine 04035 0.005

Tebuthiuron 82670 0.010

Terbacil 82665 0.007

Terbufos 82675 0.013

Thiobencarb 82681 0.002

Triallate 82678 0.001

*Triclopyr 49235 0.25

Trifluralin 82661 0.002

Volatile organic compounds, in micrograms per liter

1, 1, 1, 2-Tetrachloroethane 77562 0.044

1, 1, 1-Trichloroethane 34506 0.032

1, 1, 2, 2-Tetrachloroethane 34516 0.132

1, 1, 2-Trichloroethane 34511 0.064

1, 1, 2-Trichlorotrifluoroethane 77652 0.092

1, 1-Dichlororethane 34496 0.066

1, 1-Dichloroethylene 34501 0.044

1, 1-Dichloropropene 77168 0.026

1, 2, 3, 4-Tetramethylbenzene 49999 0.230

1, 2, 3, 5-Tetramethylbenzene 50000 0.240

1, 2, 3-Trichlorobenzene 77613 0.266

Appendix I. List of properties and constituents for ground-water-quality data in the Fraser

River watershed—Continued

[USGS, U.S. Geological Survey; NWIS, National Water Information System; na, not applicable; μS/cm, microsiemens per centimeter; mg/L, milligrams per liter; μg/L, micrograms per liter; NTU, nephelometric turbidity units;

pCi/L, picocuries per liter; cols/100 mL, colonies per 100 milliliters; pfu, plaque-forming unit; *, pesticides analyzed in only the monitoring wells]
APPENDIX 57

Constituent USGS NWIS parameter

code Reporting limit

Volatile organic compounds, in micrograms per liter–Continued

1, 2, 3-Trichloropropane 77443 0.077

1, 2, 3-Trimethylbenzene 77221 0.124

1, 2, 4-Trichlorobenzene 34551 0.188

1, 2, 4-Trimethylbenzene 77222 0.056

1, 2-Dibromo-3-chloropropane 82625 0.214

1, 2-Dibromoethane 77651 0.036

1, 2-Dichlorobenzene 34536 0.048

1, 2-Dichloroethane 32103 0.134

1, 2-Dichloropropane 34541 0.068

1, 3, 5-Trimethylbenzene 77226 0.044

1, 3-Dichlorobenzene 34566 0.054

1, 3-Dichloropropane 77173 0.116

1,4-Dichlorobenzene 34571 0.050

2, 2-Dichloropropane 77170 0.078

2-Butanone 81595 1.650

2-Chlorotoluene 77275 0.042

2-Hexanone 77103 0.746

3-Chloropropene 78109 0.196

4-Chlorotoluene 77277 0.056

4-Isopropyl-1-methylbenzene 77356 0.110

4-Methyl-2-pentanone 78133 0.374

Acetone 81552 4.900

Acrolein 34210 1.430

Acrylonitrile 34215 1.230

Benzene 34030 0.032

Bromobenzene 81555 0.036

Bromochloromethane 77297 0.044

Bromodichloromethane 32101 0.048

Bromoform 32104 0.104

Bromomethane 34413 0.148

Butylbenzene 77342 0.186

Carbon disulfide 77041 0.080

Chlorobenzene 34301 0.028

Chloroethane 34311 0.120

Chloroform 32106 0.052

Chloromethane 34418 0.254

Dibromochloromethane 32105 0.182

Dibromomethane 30217 0.050

Dichlorodifluoromethane 34668 0.096

Dichloromethane 34423 0.382

Diethyl ether 81576 0.170

Appendix I. List of properties and constituents for ground-water-quality data in the Fraser

River watershed—Continued

[USGS, U.S. Geological Survey; NWIS, National Water Information System; na, not applicable; μS/cm, microsiemens per centimeter; mg/L, milligrams per liter; μg/L, micrograms per liter; NTU, nephelometric turbidity units;

pCi/L, picocuries per liter; cols/100 mL, colonies per 100 milliliters; pfu, plaque-forming unit; *, pesticides analyzed in only the monitoring wells]
58 Fraser River Watershed, Colorado—Assessment of Available Water-Quantity and Water-Quality Data Through Water Year 1997

Constituent USGS NWIS parameter

code Reporting limit

Volatile organic compounds, in micrograms per liter–Continued

Diisopropyl ether 81577 0.098

Ethyl metracrylate 73570 0.278

Ethyl tert-butyl ether 50004 0.054

Ethylbenzene 34371 0.030

Hexachlorobutadiene 39702 0.142

Hexachloroethane 34396 0.362

Isopropylbenzene 77223 0.032

Methyl acrylate 49991 0.612

Methyl acrylonitrile 81593 0.570

Methyl iodide 77424 0.076

Methyl methacrylate 81597 0.350

Napthalene 34696 0.250

Propylbenzene 77224 0.042

Styrene 77128 0.042

Tetrachloroethylene 34475 0.038

Tetrachloromethane 32102 0.088

Tetrahydrofuran 81607 1.150

Toluene 34010 0.038

Trichloroethylene 39180 0.038

Trichlorofluoromethane 34488 0.032

Vinyl acetate 77057 5.0

Vinyl bromide 50002 0.100

Vinylchloride 39175 0.112

cis-1, 2-Dichloroethylene 77093 0.038

cis-1, 3-Dichloropropene 34704 0.092

m- and p-Xylene 85795 0.064

o-Ethyl toluene 77220 0.100

o-Xylene 77135 0.064

sec-Butylbenzene 77350 0.048

tert-Butyl methyl ether 78032 0.112

tert-Butylbenzene 77353 0.096

tert-Pentyl methyl ether 50005 0.112

trans-1, 2-Dichloroethylene 34546 0.032

trans-1, 3-Dichloropropene 34699 0.134

trans-1, 4-Dichloro-2-butene 73547 0.692

OTHER CONSTITUENTS

Coliform, total, m-ENDO agar 31501 0 cols/100 mL

Coliform, total, MI agar 90900 0 cols/100 mL

Coliphage, E. coli 90903 0 pfu

Methylene blue active substances 38260 0.02 mg/L

Appendix I. List of properties and constituents for ground-water-quality data in the Fraser

River watershed—Continued

[USGS, U.S. Geological Survey; NWIS, National Water Information System; na, not applicable; μS/cm, microsiemens per centimeter; mg/L, milligrams per liter; μg/L, micrograms per liter; NTU, nephelometric turbidity units;

pCi/L, picocuries per liter; cols/100 mL, colonies per 100 milliliters; pfu, plaque-forming unit; *, pesticides analyzed in only the monitoring wells]