U.S. Department of the Interior

U.S. Geological Survey

Prepared in cooperation with:

Virginia Department of Conservation and Recreation

Patterns and Sources of Fecal Coliform Bacteria in 

Three Streams in Virginia, 1999-2000

Water-Resources Investigations Report 03-4115

FECAL COLIFORM CONCENTRATIONS,

IN COLONIES PER 100 MILLILITERS

DISCHARGE, IN CUBIC FEET PER SECOND

50

100

150

200

250

300

350

0

50,000

100,000

150,000

200,000

250,000

300,000

Discharge, in cubic 

feet per second

Fecal coliforms

0 10 20 30 50 40 60 70

TOTAL HOURS ELAPSED
Representative agricultural, urban, and forested streams (Photographs by K.E. Hyer and D.L. Moyer, U.S. Geological Survey)
U.S. Department of the Interior

U.S. Geological Survey

Patterns and Sources of Fecal Coliform Bacteria in 

Three Streams in Virginia, 1999-2000

By Kenneth E. Hyer and Douglas L. Moyer

Water-Resources Investigations Report 03-4115

Prepared in cooperation with:

Virginia Department of Conservation and Recreation

Virginia Department of Environmental Quality

Fairfax County, Virginia

Richmond, Virginia

2003
U.S. DEPARTMENT OF THE INTERIOR

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

The use of trade or product names in this report is for identification purposes 

only and does not constitute endorsement by the U.S. Government.

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

District Chief U.S. Geological Survey

U.S. Geological Survey Branch of Information Services

1730 East Parham Road Box 25286, Federal Center

Richmond, VA 23228 Denver, CO 80225-0286

dc_va@usgs.gov

Information about water resources in Virginia is available on the World Wide Web at http://va.water.usgs.gov
Contents III

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

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

Purpose and scope ........................................................................................................................................................................ 3

Acknowledgments ......................................................................................................................................................................... 3

Description of the study areas ................................................................................................................................................................ 3

Accotink Creek ............................................................................................................................................................................... 4

Christians Creek ............................................................................................................................................................................. 7

Blacks Run ....................................................................................................................................................................................... 9

Methods ...................................................................................................................................................................................................... 11

Water-sample collection for bacteria ......................................................................................................................................... 11

Supporting field measurements ................................................................................................................................................... 12

Fecal coliform enumeration .......................................................................................................................................................... 12

E. coli enumeration ........................................................................................................................................................................ 13

Bacterial source tracking ............................................................................................................................................................. 13

Source-sample collection and source library development ................................................................................................... 16

Patterns and sources of fecal coliform bacteria ................................................................................................................................. 16

Overview of the water samples collected ................................................................................................................................. 16

Fecal coliform analyses ................................................................................................................................................................. 16

Spatial patterns in the fecal coliform concentrations .................................................................................................. 16

Temporal patterns in the fecal coliform concentrations .............................................................................................. 18

Correlations between fecal coliform concentrations and streamwater parameters ............................................. 22

Analysis of replicate fecal coliform enumerations ........................................................................................................ 26

Bacteria sources in the three streams ....................................................................................................................................... 28

Samples submitted for source tracking .......................................................................................................................... 28

Results of the bacterial source tracking ......................................................................................................................... 28

Temporal variability in the bacteria sources .................................................................................................................. 33

Quality control for the ribotyping results ........................................................................................................................ 36

Source-library development and application ................................................................................................................. 39

Future directions ........................................................................................................................................................................................ 41

Summary and conclusions ....................................................................................................................................................................... 41

References cited ....................................................................................................................................................................................... 43

Appendix ..................................................................................................................................................................................................... 45

Figures

1-4. Maps showing:

1. Location of Accotink Creek, Blacks Run, and Christians Creek watersheds, and physiographic 

provinces in Virginia ........................................................................................................................................................... 5

2. Land use, streams, and sampling stations in the Accotink Creek watershed, 

Fairfax County, Virginia ....................................................................................................................................................... 6

3. Land use, streams, and sampling stations in the Christians Creek watershed, 

Augusta County, Virginia .................................................................................................................................................... 8

4. Land use, streams, and sampling stations in the Blacks Run watershed, 

Rockingham County, Virginia ............................................................................................................................................. 10

5-6. Graphs showing:

5. Storm-flow sampling design for bacterial source tracking study ............................................................................... 12

6. Relation of fecal coliform and E. coli concentrations in water samples ................................................................... 13

7. Photograph showing example of the banding patterns produced by the ribotyping procedure ................................... 15

8-19. Graphs showing:

CONTENTS
IV Contents

8. Fecal coliform concentrations during low-flow sampling ............................................................................................ 19

9. Fecal coliform concentrations during storm-flow sampling ........................................................................................ 21

10. Changes in discharge, fecal coliform concentrations, and supporting water-quality 

parameters during storm events ....................................................................................................................................... 23

11. Relations of observed and predicted fecal coliform concentrations as a function 

of water-quality parameters .............................................................................................................................................. 27

12. Distribution of the bacteria isolates that were identified in streamwater samples ................................................. 30

13. Distribution of the bacteria isolates that were identified in streamwater samples after 

combining the poultry sources and distributing the avian sources ........................................................................... 31

14. Bacteria sources identified in stream-water samples .................................................................................................. 32

15. Land use in the Accotink Creek, Blacks Run, and Christians Creek watersheds .................................................... 32

16. Distribution of identified bacteria sources in two neighboring watersheds ............................................................. 34

17. Top eight bacteria sources from low-flow and storm-flow stream-water samples 

collected March 1999 through October 2000 .................................................................................................................. 35

18. Top eight bacteria sources from low-flow stream-water samples collected 

April through September 1999 and October 1999 through March 2000 ...................................................................... 37

19. Caffeine and estimated cotinine concentrations ........................................................................................................... 39

Tables

1. Permitted point-source dischargers of fecal coliform bacteria in Christians Creek

watershed during 2000, Augusta County, Virginia ......................................................................................................... 7

2. Number and type of streamwater samples collected from March 1999 through 

October 2000 in three watersheds in Virginia ................................................................................................................. 16

3. Fecal coliform concentrations of the continuum samples ........................................................................................... 17

4. Fecal coliform concentrations of water samples collected in the 

Accotink Creek watershed ................................................................................................................................................ 18

5. Number of E. coli isolates ribotyped, and percentage of those isolates from low-flow samples ......................... 28

6 Design of the quality-control experiment for the ribotyping analysis used in this study ........................................ 38

7. Summary of source samples collected ........................................................................................................................... 40

8. Summary of databases used to identify the source of each isolate .......................................................................... 41

Appendix

1. Bacterial source tracking data from streamwater samples collected March 1999 

through October 2000 .......................................................................................................................................................... 45
 Contents V 

Horizontal coordinate information is referenced to the North American Datum of 1927 (NAD27).

Temperature: Temperature is reported in degrees Celsius (°C), which can be converted to degrees Fahrenheit (°F) as follows: °F = 1.8 (°C) + 32°

Abbreviated water-quality units: Chemical concentration is reported in milligrams per liter (mg/L) or micrograms per liter (μg/L). Milligrams per liter is a unit 

expressing the concentration of chemical constituents in solution as mass (milligrams) of solute per unit volume (liter) of water. One-thousand micrograms per liter 

is equivalent to 1 milligram per liter. For concentrations less than 7,000 mg/L, the numerical value is the same as for concentrations in parts per million. Bacterial 

concentrations are reported in units of colonies per 100 milliliters (col/100mL). Specific electrical conductance of water is reported in microsiemens per centimeter 

at 25 degrees Celsius (μS/cm). Turbidity is reported in nephelometric turbidity units (NTU).

Multiply By To obtain

Length

inch (in.) 25.4 millimeter

foot (ft) 0.3048 meter

mile (mi) 1.609 kilometer

Area

square mile (mi2) 259.0 hectare

square mile (mi2) 2.590 square kilometer

Volume

gallon (gal) 3.785 liter

gallon (gal) 0.003785 cubic meter

Flow

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

gallons per day 0.003785 cubic meter per day

million gallons per day (Mgal/d) 0.04381 cubic meter per second

CONVERSION FACTORS, DATUM, AND ABBREVIATED WATER-QUALITY UNITS
IV Contents
Abstract 1

ABSTRACT

Surface-water impairment by fecal coliform 

bacteria is a water-quality issue of national scope 

and importance. In Virginia, more than 175 stream 

segments are on the Commonwealth’s 1998 303(d) 

list of impaired waters because of elevated 

concentrations of fecal coliform bacteria. These 

fecal coliform-impaired stream segments require 

the development of total maximum daily load 

(TMDL) and associated implementation plans, but 

accurate information on the sources contributing 

these bacteria usually is lacking. The development 

of defendable fecal coliform TMDLs and 

management plans can benefit from reliable 

information on the bacteria sources that are 

responsible for the impairment. Bacterial source 

tracking (BST) recently has emerged as a powerful 

tool for identifying the sources of fecal coliform 

bacteria that impair surface waters. In a 

demonstration of BST technology, three 

watersheds on Virginia’s 1998 303(d) list with 

diverse land-use practices (and potentially diverse 

bacteria sources) were studied. Accotink Creek is 

dominated by urban land uses, Christians Creek by 

agricultural land uses, and Blacks Run is affected 

by both urban and agricultural land uses. During 

the 20-month field study (March 1999–October 

2000), water samples were collected from each 

stream during a range of flow conditions and 

seasons. For each sample, specific conductance, 

dissolved oxygen concentration, pH, turbidity, 

flow, and water temperature were measured. Fecal 

coliform concentrations of each water sample 

were determined using the membrane filtration 

technique. Next, Escherichia coli (E. coli) were 

isolated from the fecal coliform bacteria and their 

sources were identified using ribotyping (a method 

of “genetic fingerprinting”).

Study results provide enhanced understanding 

of the concentrations and sources of fecal coliform 

bacteria in these three watersheds. Continuum 

sampling (sampling along the length of the 

streams) indicated that elevated concentrations of 

fecal coliform bacteria (maximum observed concentration of 290,000 colonies/100 milliliters 

(col/100mL) could occur along the entire length of 

each stream, and that the samples collected at the 

downstream monitoring station of each stream 

were generally representative of the entire 

upstream reach. Seasonal patterns were observed 

in the base-flow fecal coliform concentrations of 

all streams; concentrations were typically highest 

in the summer and lowest in the winter. Fecal 

coliform concentrations were lowest during periods of base flow (typically 200–2,000 col/100mL) 

and increased by 3–4 orders of magnitude during 

storm events (as high as 700,000 col/100mL). 

Multiple linear regression models were developed 

to predict fecal coliform concentrations as a function of streamflow and other water-quality parameters. The source tracking technique provided 

identification of bacteria contributions from 

diverse sources that included (but were not limited 

to) humans, cattle, poultry, horses, dogs, cats, 

geese, ducks, raccoons, and deer. Seasonal patterns were observed in the contributions of cattle 

and poultry sources. There were relations between 

the identified sources of fecal coliform bacteria 

and the land-use practices within each watershed. 

There were only minor differences in the distribution of bacteria sources between low-flow periods 

and high-flow periods. A coupled approach that 

utilized both a large available source library and a 

smaller, location-specific source library provided 

the most success in identifying the unknown E. 

coli isolates. BST data should provide valuable 

support and guidance for producing more defendPatterns and Sources of Fecal Coliform Bacteria in Three 

Streams in Virginia, 1999-2000

By Kenneth E. Hyer and Douglas L. Moyer
2 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

able and scientifically rigorous watershed models. 

Incorporation of these bacteria-source data into 

watershed management strategies also should 

result in the selection of more efficient 

source-reduction scenarios for improving water 

quality.

INTRODUCTION

Surface-water impairment by fecal coliform 

bacteria is a water-quality issue of national scope and 

importance. Section 303(d) of the Clean Water Act 

requires that each State identify surface waters that do 

not meet applicable water-quality standards. In Virginia, more than 175 stream segments are on the Commonwealth’s 1998 303(d) list of impaired waters 

because of violations of the fecal coliform bacteria 

standard (an instantaneous water-quality standard of 

1,000 col/100 mL, or a geometric mean water-quality 

standard of 200 col/100 mL). Fecal coliform concentrations that violate either standard indicate an increased 

risk to human health when these waters are contacted 

through swimming or other recreational activities.

 In Virginia, total maximum daily load (TMDL) 

plans will need to be developed over the next 10 years 

for all impaired water bodies identified on the State’s 

1998 303(d) list. TMDL plans provide a quantitative 

representation of all the contaminant contributions to a 

stream:

 TMDL = ∑WLAi + ∑LAi + MOS 

where ∑WLAi represents the sum of all the 

point-source loadings, ∑LAi represents the sum of all 

the nonpoint-source loadings, and MOS represents a 

margin of safety. The sum of these loading terms and 

assigned margin of safety constitutes the TMDL and 

represents the fecal coliform loading that the 

surface-water body can assimilate without violating the 

state’s water-quality standards. For a TMDL plan to be 

approved by the U.S. Environmental Protection 

Agency (USEPA), all major fecal coliform contributions to the stream must be identified and quantified. 

Once a TMDL plan is established, fecal coliform 

source-load contributions are then reduced (through 

implementation of source-control management practices) until the target TMDL is achieved. 

Establishing TMDLs in waters contaminated by 

fecal coliform bacteria is difficult because the specific 

sources of the bacteria are numerous and the magnitude 

of their contributions is commonly unknown. Potential 

sources of fecal coliform bacteria include all 

warm-blooded animals (humans, pets, domesticated 

livestock, birds, and wildlife). The lack of information 

on bacteria sources makes it difficult to develop accurate load allocations, technically defensible TMDLs, 

and appropriate source-load reduction measures. Information about the major fecal coliform sources that 

impair surface-water quality would represent a major 

improvement in the development of technically defensible TMDLs.

Bacterial source tracking (BST) recently has 

emerged as a tool for identifying the sources of fecal 

coliform bacteria that impair surface waters. In application, this technology identifies specific differences 

among the fecal coliform bacteria that are present in 

the feces of different animal species. Time, diet, environment, and many other factors may have contributed 

to produce these evolutionary distinctions; these distinctions are used in BST to identify the animal source 

of fecal coliform bacteria that have been isolated from 

a waterbody.

BST is a rapidly growing technology with various 

analytical techniques available, depending on the goals 

of the study. In general, these techniques rely on 

molecular, genetics-based approaches (also known as 

“genetic fingerprinting”), or phenotypic (relating to the 

physical characteristics of an organism) distinctions 

between the bacteria of different sources. Three primary genetic techniques are available for BST. 

Ribotyping characterizes a small, specific portion of 

the bacteria’s DNA sequence (Samadpour and 

Chechowitz, 1995). Pulsed-field gel electrophoresis 

(PFGE) is similar to ribotyping but typically is performed on the entire genome of the bacteria (Simmons 

and others, 1995). Polymerase chain reaction (PCR) 

amplifies selected DNA sequences in the bacteria’s 

genome (Makino and others, 1999). Phenotypic techniques generally involve an antibiotic resistance analysis, where resistance patterns for a suite of different 

concentrations and types of antibiotics are developed 

(Wiggins, 1996; Hagedorn and others, 1999).

Although all these techniques show promise for 

bacteria source identification, the ribotyping technique 

was chosen for this study. Ribotyping involves an analysis of the specific DNA sequence that codes for the 

production of ribosomal RNA (ribonucleic acid). 

Ribotyping has been demonstrated to be an effective 

technique for distinguishing bacteria from the feces of 

(1)
Description of the Study Areas 3

multiple animal sources (Carson and others, 2001); it 

has been performed successfully and used to identify 

fecal coliform bacteria sources in both freshwater 

(Samadpour and Chechowitz, 1995) and estuarine systems (Ongerth and Samadpour, 1994). Furthermore, the 

technique has been used to identify the sources of bacteria contributing to impairments in both urban (Herrera Environmental Consultants, Inc., 1993) and wilderness systems (Farag and others, 2001). The broad 

applicability of ribotyping makes it well suited for use 

in this study.

This study was performed to demonstrate the field 

application of BST technology and to identify the 

sources of fecal coliform bacteria in three streams on 

Virginia’s 1998 303(d) list of impaired waters. The 

three streams sampled during this study were selected 

because they represent a range of land uses (urban, 

agricultural, and mixed urban/agricultural) and most of 

the potential fecal coliform sources that are likely to be 

encountered throughout the Commonwealth. The three 

streams were sampled over a period of 20 months 

(March 1999–October 2000) and over a wide range of 

hydrological conditions. For all samples, the fecal 

coliform concentration, specific conductance, turbidity, 

pH, water temperature, and dissolved oxygen concentration were determined. Ribotyping was used to identify the sources of the fecal coliform bacteria. The 

results of this study have broad implications for the 

development of fecal coliform watershed models, 

selection of TMDL allocation scenarios, and the identification of effective strategies for reducing fecal 

coliform contributions to streams. The U. S. Geological 

Survey (USGS) conducted this study in cooperation 

with the Virginia Department of Environmental Quality 

(DEQ), Virginia Department of Conservation and Recreation (DCR), and Fairfax County, Virginia.

Purpose and Scope

This report demonstrates the field application of 

bacterial source tracking technology, which was used 

to identify the sources of fecal coliform bacteria in 

three streams that are on Virginia’s 1998 303(d) list of 

impaired waters. Streamwater data were collected from 

March 1999 through October 2000, under both 

base-flow and storm-flow conditions. Concentrations 

of fecal coliform bacteria were determined at the 

stream gage and 4–5 other locations in each watershed; 

bacterial source tracking was performed only on the 

samples that were collected at the stream gage in each 

watershed. In addition to identifying the sources of 

fecal coliform bacteria in the three streams, the report 

describes (1) seasonal and discharge-related patterns in 

the concentrations of fecal coliform bacteria, (2) multiple linear regression models for predicting fecal 

coliform concentrations as a function of supporting 

water-quality field parameters, (3) seasonal and 

discharge-related patterns in the identified bacteria 

sources of each stream, and (4) the effect of 

source-library size on the identification of bacteria. 

Study results have broad implications for the interpretation of source-tracking data and the development of 

TMDL plans in impaired streams.

Acknowledgments

The authors acknowledge USGS employees 

Michael Gearheart, Trisha Baldwin, and Russ 

Lotspeich for providing outstanding technical support 

on this project. Don Stoeckel and Michael Focazio of 

USGS are thanked for providing technical reviews of 

this report. The following organization and persons 

assisted in collecting the scat samples that were used 

for developing a portion of the known-source database: 

The Wildlife Center of Virginia, Michael Noto (James 

Madison University), Kay Rutledge (Fairfax County, 

Wastewater Treatment Division), Robert Heavener 

(Rockingham County Sewer Authority), Melissa Harris 

(Augusta County Service Authority), and Greg Zell 

(Arlington County, Department of Parks, Recreation, 

and Community Resources). Michael Noto also 

assisted in collecting additional continuum samples in 

Blacks Run. Lastly, we are indebted to the residents, 

farmers, and stakeholders in all three watersheds for 

their enthusiastic participation in this study. 

DESCRIPTION OF THE STUDY AREAS

Three stream segments on Virginia’s 1998 303(d) 

list were selected for this study. The streams in Virginia 

that are impaired by fecal coliform bacteria drain 

watersheds that generally can be categorized into one 

of three land-use practices: agricultural, urban, and 

mixed urban/agricultural. To represent a range of land 

uses and potential sources of fecal contamination, a 

representative study site was selected from each of 

these land-use types. The criteria evaluated for site 
4 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

selection included (1) presence of a stream gage, (2) 

size of watershed (about 100 mi2 or smaller), (3) 

well-defined and stable land-use patterns, (4) availability of historical water-quality data, (5) availability of 

up-to-date geographic information system (GIS) coverages, and (6) support from the local community. The 

three sites selected for this study (fig. 1) were Accotink 

Creek (representing urban land use), Christians Creek 

(agricultural land use), and Blacks Run (mixed urban 

and agricultural land use). The data collected during 

this study are being used in a separate watershed modeling and TMDL development study by the USGS 

(Moyer and Hyer, in press).

Accotink Creek

Accotink Creek near Annandale, Va., is the urban 

watershed selected for this study (fig. 2). The headwaters of Accotink Creek are in the city of Fairfax, Va., 

and the creek flows for approximately 10.9 mi before it 

drains into Lake Accotink, located in Fairfax County. 

The impaired stream reach is a 4.5-mi-long section just 

upstream of Lake Accotink. The portion of the 

Accotink Creek watershed studied has a drainage basin 

area of 25 mi2 and a population of more than 110,000 

(2000 U.S. Census Bureau data). Approximately 600 ft 

upstream from the bridge at Route 620 (Braddock 

Road) is a stream gage that has been active since 1949 

and is managed by DEQ (USGS station number 

01654000). DEQ has performed quarterly sampling for 

fecal coliform bacteria at the bridge at Route 620 since 

1990. Currently, there are no permitted fecal coliform 

point source dischargers within the watershed 

(J. Crowther, Virginia Department of Environmental 

Quality, written commun., 1999).

Although portions of the watershed are forested 

(especially adjacent to the stream), urban and residential land uses dominate the majority of the watershed. 

Potential sources of fecal contamination in this urban 

watershed include domestic pets (such as dogs and 

cats), wildlife (such as raccoons, opossum, rats, squirrels, and deer), waterfowl (such as geese, ducks, and 

sea gulls), and humans (as contributed by cross-pipes, 

leaking or overflowing sewer lines, and failing septic 

systems).

The Accotink Creek watershed lies in the Piedmont 

physiographic province, and is underlain by crystalline 

igneous and metamorphic rocks (Froelich and Zenone, 

1985). The surficial geology of the watershed is composed of five formations. The Wissahickon Formation 

dominates the watershed and is composed of 

quartz-mica schist, phyllite, and quartzite (Johnston, 

1964). The Greenstone Contact Complex is present in 

some headwater areas of the catchment and is composed of chlorite schist, sericite-chlorite schist, chlorite-quartz schist, talc schist and small amounts of 

quartzite (Johnston, 1962). Granitic rocks are distributed throughout the watershed; these rocks are of variable composition and include biotite granite, muscovite 

granite, biotite-muscovite granite, granodiorite, quartz 

monzonite, and quartz diorite (Johnston, 1964). A 

small portion of the watershed is underlain by the 

Sykesville Formation, which includes muscovite or 

sericite-biotite-quartz schist and gneiss, quartzite, epidote quartzite, and muscovite-biotite quartzite 

(Johnston, 1964). Alluvial material (composed of clay 

and sand, as well as quartz cobbles and pebbles) also is 

present along the channel and in the floodplain of 

Accotink Creek (Johnston, 1962). 

The soils of the Accotink Creek watershed are 

present as three distinct soil associations, described by 

Porter and others (1963). The Glenelg-Elioak-Manor 

association has developed from the weathering of the 

crystalline bedrock of the Piedmont. These 

well-drained (and, in some places, excessively drained) 

silt-loam soils dominate the watershed. The 

Fairfax-Beltsville-Glenelg association comprises a relatively small portion of the watershed (limited to the 

headwater areas) and formed from the residuum of 

Piedmont bedrock and fluvial Coastal Plain sediments. 

These soils are present as silt or sand loams, and range 

from somewhat poorly drained to well drained. The 

Chewacla-Wehadkee association occurs only on a limited basis within the watershed, generally in the bottomland and in floodplains along streams. These 

silt-loam soils range from moderately well drained to 

poorly drained and have developed from alluvial 

material that was washed from the Piedmont uplands. 

Most water-quality data for this study were collected from the Accotink Creek stream gage (station 

number 01654000); this site also is a DEQ ambient 

water-quality sampling station. Four additional stations 

where data were collected (continuum sampling sites) 

along Accotink Creek are at Route 237 (Pickett Road, 

station number 01653900), Route 846 (Woodburn 

Road, station number 01653985), Woodlark Drive (station number 01653995), and Lonsdale Drive (station 

number 01654520).
Description of the Study Areas 5 Figure 1. Location of Accotink Creek, Blacks Run, and Christians Creek watersheds, and physiographic provinces in Virginia.

82o

80o

78o

37o

38o

39o

0 25 

50 

0 25 50 75 100 

APPALACHIAN PLATEAU VALLEY AND RIDGE

BLUE RIDGE

PIEDMONT

COASTAL PLAI

AF

Christians Creek watershed,Augusta County

Blacks Run watershed,Rockingham County

County boundaries from 1:100,000, TIGER files, 1994Universal Transverse Mercator 18 projection, NAD 27, central meridian 75o00'W

Base from USGS Digital Line Graph, 1:2,000,000, 1987

TENNESSEE NORTH CAROLINA

KENTUCKY

MARYLAND WEST VIRGINIA
6 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

Figure 2. Land use, streams, and sampling stations in the Accotink Creek watershed, Fairfax County, Virginia.

77 ̊ 16'

77 ̊ 18'

77 ̊ 20'

38 ̊ 54'

38 ̊ 52'

38 ̊ 50'

38 ̊ 48'

77 ̊ 14'

77 ̊ 12'

66

495

Fairfax

FAIRFAX CO

Accotink

Creek

Accotink

Creek

01653900 01653900

01653985 01653985

01653995 01653995

01654000 01654000

1AACO014.57 1AACO014.57 01654520 01654520

Lake Accotink

Accotink Creek 

watershed

COASTAL PLAIN

PIEDMONT

BLUE RIDGE

APPALACHIAN

PLATEAU

VALLEY

AND

RIDGE

0 1 2 MILES

0 1 2 KILOMETERS

EXPLANATION

Urban

Residential

Forested

Grasslands

Wetlands

LAND USE

Land use from U.S. Environmental Protection Agency Multi-Resolution Land Characteristics 

 Region 3, 1993, 30-meter resolution

County boundaries from 1:100,000, TIGER files, 1994

Hydrography digitized from 1:24,000, 7.5-minute quadrangles

Universal Transverse Mercator 18 projection, NAD 27, central meridian 75o00'W

Base from USGS Digital Elevation Model 7.5-minute quadrangles, 30-meter resolution

U.S. Geological Survey station number and Virginia 

Department of Environmental Quality stream gage, 

ambient water-quality sampling station and 

station number

U.S. Geological Survey continuum sampling site 

and station number

1AACO014.57

01654000

01654520

Impaired reach—Classified as impaired with 

respect to fecal coliform bacteria by the Virginia 

Department of Environmental Quality

Nonimpaired reach

Turkey

Run

Crook

Branch

Daniels

Run

Coon Branch

Long

Branch

Bear

Branch

Hunter

Run

Annandale
Description of the Study Areas 7

Christians Creek

Christians Creek, located in Augusta County, is the 

agricultural watershed selected for this study (fig. 3). 

Christians Creek originates northwest of Greenville, 

Va., and extends to the confluence with the Middle 

River. The entire 31.5-mi-long reach is classified as 

impaired with respect to fecal coliform bacteria. The 

watershed has a drainage area of 107 mi2. The population of the watershed is estimated to be 12,000 (1990 

U.S. Census Bureau data). There is a recently (1997) 

deactivated stream gage (still operational for instantaneous stage determinations) at Route 794 (Sangers 

Lane, station number 01624800), with a period of 

record from 1967 to 1997. DEQ has sampled for fecal 

coliform bacteria at Route 794 and Route 831 (Old 

White Hill Road, station number 1BCST021.76) on a 

monthly basis since 1991. The ambient water-quality 

sampling station at Route 794 was the primary Christians Creek sampling location for this study.

There are 18 permitted point source dischargers in 

the watershed (B.K. Fowler, Virginia Department of 

Environmental Quality, written commun., 2000; 

table 1). The Fishersville Sewage Treatment Plant discharges into Christians Creek about 1,500 ft upstream 

from one of the USGS and DEQ water-quality sampling locations (Route 794). On various occasions, the 

outfall from this sewage-treatment plant was sampled 

to check that it was not an important contributor of 

fecal coliform bacteria to the stream. As permitted, 

none of these point sources contributes greater than 

200 col/100 mL to Christians Creek. None of these 

point sources represents a large flow contribution to 

Christians Creek; cumulatively, these sources account 

for less than 5 percent of the daily flow in the creek. 

The 12 private permitted dischargers in the watershed 

are 9 family residences and 3 small businesses.

Land use within the watershed is dominated by 

agricultural practices that are potential sources of fecal 

coliform bacteria within the watershed. Major components of animal husbandry in this watershed include the 

production of beef cattle, dairy cattle, heifers, broilers, 

and turkeys. Other potential fecal coliform bacteria 

sources within the watershed include humans (as contributed by failing septic systems, leaking or overflowing sewer lines, cross-pipes, and straight pipes), 

domestic animals (such as dogs and cats), waterfowl 

(such as geese, ducks, and sea gulls), and wildlife (such 

as deer, raccoons, opossum, rabbits, muskrats, ground 

hogs, foxes, and beaver).

The Christians Creek watershed lies within the Valley and Ridge physiographic province. The surficial 

geology that underlies the drainage basin is composed 

of 10 formations and is dominated by limestone and 

dolomite; information about each formation is summarized from Rader (1967). The Martinsburg Formation 

(calcareous shale and sandstone) is the dominant formation within the basin. Other formations in the watershed include the Edinburg Formation (argillaceous 

limestone and shale), Lincolnshire Formation (cherty 

limestone), New Market Limestone (limestone with 

dolomite beds near the base), Beekmantown Formation 

(dolomite and limestone), Chepultepec Formation 

(limestone and dolomite), Conococheague Formation

Discharger Discharge

(Mgal/d) Latitude Longitude

Fishersville Sewage Treatment Plant 0.7 38o07’41” 78o59’46”

Staunton Plaza Sewage Treatment Plant .09 38o06’45” 79o03’18”

Brookwood Interchange Sewage Treatment Plant .03 38o04’26” 79o04’56”

Riverheads High School Sewage Treatment Plant .014 38o01’47” 79o08’27”

Southern States Cooperative 0 38o06’09” 79o04’24”

Woodlawn Village Mobile Home Park .007 38o08’53” 78o55’06”

12 private permitted dischargers .001 Various Various

Table 1. Permitted point-source dischargers of fecal coliform bacteria in Christians Creek watershed during 

2000, Augusta County, Virginia (B.K. Fowler, Virginia Department of Environmental Quality, written commun., 

2000)

[Mgal/d, million gallons per day]
8 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

Figure 3. Land use, streams, and sampling stations in the Christians Creek watershed, Augusta County, Virginia.

79 ̊ 10'

79 ̊ 05'

79 ̊

78 ̊ 55'

38 ̊ 10'

38 ̊ 05'

0 2 4 MILES

0 2 4 KILOMETERS

64

64

81

AUGUSTA COAUGUSTA CO

Greenville Greenville Christians

Creek

Christians

Creek

Christians Creek

watershed

COASTAL PLAIN

PIEDMONT

BLUE RIDGE

APPALACHIAN

PLATEAU

VALLEY

AND

RIDGE

EXPLANATION

U.S. Geological Survey stream gage (currently inactive) and 

station number and Virginia Department of Environmental 

Quality ambient water-quality sampling station and 

station number

U.S. Geological Survey continuum sampling site 

and station number

Virginia Department of Environmental 

Quality ambient water-quality 

sampling station and station number

Urban

Residential

Forested

Pasture

Cropland

Hayland

LAND USE

1BCST012.32

1BCST021.76

01624800

01624615 01624615

01624615

Impaired reach—Classified as impaired with respect to fecal coliform 

bacteria by the Virginia Department of Environmental Quality

Nonimpaired reach

01624660 01624660

01624700 01624700

01624800 01624800

01624900 01624900

01624620 01624620

Middle River

1BCST021.76 1BCST021.76

1BCST012.32 1BCST012.32

County boundaries from 1:100,000, TIGER files, 1994

Land use from Virginia Department of Conservation and Recreation, Carterra imagery 1996, 1997, and 1998,

5-meter resolution panchromatic Indian Remote Sensing fused with 1997 Landsat, 30-meter resolution

Hydrography digitized from 1:24,000, 7.5-minute quadrangles

Universal Transverse Mercator 17 projection, NAD 27, central meridian 81

o

00'W

Base from USGS Digital Elevation Model 7.5-minute quadrangles, 30-meter resolution
Description of the Study Areas 9

(limestone, dolomite, and sandstone), and Elbrook Formation (limestone and dolomite). Alluvial material 

(composed of sand and clay) is present in portions of 

the floodplain adjacent to Christians Creek. Small 

amounts of fault breccia (large blocks of dolomite and 

limestone with crush conglomerate) also are present in 

the basin.

The soils of the Christians Creek watershed have 

been described thoroughly (Hockman and others, 

1979) and are best classified as derived from the parent 

material from which they were formed. Much of the 

soil in the watershed has formed from the residuum of 

interbedded limestone, dolomite, and calcareous shale. 

Three soil assemblages have been identified in this category. The Frederick-Christian-Rock outcrop assemblage consists of deep, well-drained, silt loam or fine 

sandy loam soils with limestone outcrop areas. The 

Frederick-Bookwood-Christian assemblage consists of 

deep to moderately deep, well-drained, silt loam or fine 

sandy loam soils; scattered sinkholes or rock outcrops 

also may be present. The Chilhowie-Edom assemblage 

consists of deep to moderately deep, well-drained, silt 

loam or silty clay loam soils with occasional bedrock 

outcrops. Soil also has formed from the residuum of 

shale and thin interbedded sandstone and limestone. 

These soils are a part of the Berks-Weikert-Sequoia 

assemblage, which consists of shallow to deep, 

well-drained, silt loam or shaly silt loam soils. On 

floodplains and terraces, soils have formed in the alluvial or colluvial material. Although not extensive 

within the watershed, these soils are part of the 

Buchanan-Wheeling-Buckton assemblage, which consists of deep, somewhat poorly drained to well-drained 

soils. Generally these soils consist of silt loam, loam, or 

fine sandy loam, although some soils are gravelly or 

cobbly.

Most water-quality data were collected from Christians Creek below the bridge at Route 794 (Sangers 

Lane, station number 01624800); this site also is a 

DEQ ambient water-quality sampling station. Five 

additional sampling stations (continuum sampling 

sites) along Christians Creek were at the spring near 

Route 693 (Berry Moore Road, station number 

01624615), Route 604 (McClures Mill Road, station 

number 01624620), Route 340 (Stuarts Draft Highway, 

station number 01624660), Route 635 (Barterbrook 

Road, station number 01624700), and Route 612 (Laurel Hill Road, station number 01624900).

Blacks Run

Blacks Run, located in Rockingham County, is the 

mixed urban and agricultural watershed selected for 

this study (fig. 4). Blacks Run originates on the north 

side of the city of Harrisonburg and extends to the confluence of Cooks Creek. The entire 10.7-mi-long reach 

is classified as impaired with respect to fecal coliform 

bacteria. The watershed has a drainage area of 20 mi2

and an estimated population of 34,700 (1990 U.S. Census Bureau data). The city of Harrisonburg is the primary urban area within the watershed. This stream, like 

many in Virginia, did not have a stream gage, so one 

was installed (station number 01621470) at Route 704 

(Cecil Wampler Road) in 1999. DEQ has sampled for 

fecal coliform bacteria at this station on a monthly 

basis since 1991.

There are no sewage-treatment plants in the Blacks 

Run watershed, but there are two private permitted dischargers, one family residence and one small business 

(B.K. Fowler, Virginia Department of Environmental 

Quality, written commun., 2000). Under the discharge 

permits, the treated wastewater discharge may not 

exceed 1,000 gallons per day and may not contain fecal 

coliform bacteria concentrations that exceed 

200 col/100 mL. 

Approximately two-thirds of the watershed (generally the portion closer to the headwaters) is dominated 

by urban land uses. In this urban area, potentially major 

contributors of fecal coliform bacteria include humans 

(as contributed by cross-pipes, failing septic systems, 

and leaking or overflowing sewer lines), domestic animals (such as dogs and cats), waterfowl (such as geese, 

ducks, and sea gulls), and wildlife (such as raccoons, 

opossum, rats, squirrels, and deer). The remaining 

one-third of the watershed (the lower portion of the 

watershed, closer to the stream gage) is dominated by 

agricultural land uses. Major components of the animal 

husbandry in this watershed include the production of 

beef cattle, dairy cattle, heifers, chickens, broilers, and 

turkeys. Other potential contributors in this agricultural 

area include humans (as contributed by failing septic 

systems, leaking or overflowing sewer lines, 

cross-pipes, and straight pipes), domestic animals 

(such as dogs and cats), waterfowl (such as geese, 

ducks, and sea gulls), and wildlife (such as deer, raccoons, opossum, rabbits, muskrats, ground hogs, foxes, 

and beaver).

The Blacks Run watershed lies within the Valley 

and Ridge physiographic province. The surficial geol
10 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

Figure 4. Land use, streams, and sampling stations in the Blacks Run watershed, Rockingham County, Virginia. Streams that appear disconnected are continuous; 

however, development activities within the watershed have captured these streams and routed the streamflow under portions of the city of 

Harrisonburg. Barren areas are primarily quarries.

EXPLANATION

Urban

Residential

Forested

Pasture

Cropland

Hayland

Barren

LAND USE

U.S. Geological Survey stream gage (inactive) 

and station number and Virginia Department of 

Environmental Quality ambient water-quality 

sampling station and station number

U.S. Geological Survey continuum sampling 

site and station number

1BBLK000.38

016221470

01621440

Impaired reach—Classified as impaired with respect to 

fecal coliform bacteria by the Virginia Department of 

Environmental Quality

Nonimpaired reach

78 ̊ 50'

78 ̊ 52'

78 ̊ 54'

78 ̊ 56'

38 ̊ 28'

38 ̊ 26'

38 ̊ 24' 0 1 2 MILES

0 1 2 KILOMETERS

ROCKINGHAM CO

Harrisonburg

Harrisonburg

ROCKINGHAM CO

Blacks

Run

Blacks

Run

Blacks Run 

watershed

COASTAL PLAIN

PIEDMONT

BLUE RIDGE

APPALACHIAN

PLATEAU

VALLEY

AND

RIDGE

01621470 01621470

1BBLK000.38 1BBLK000.38

01621440 01621440

01621425 01621425

01621410 01621410

01621397 01621397

01621395 01621395

Cooks Creek

33

81

Land use from Virginia Department of Conservation and Recreation, Carterra imagery 1996, 1997

 and 1998, 5-meter resolution panchromatic Indian Remote Sensing fused with 1997 Landsat, 

 30-meter resolution

County boundaries from 1:100,000, TIGER files, 1994

Hydrography digitized from 1:24,000, 7.5-minute quadrangles

Universal Transverse Mercator 17 projection, NAD 27, central meridian 81

o

00'W

Base from USGS Digital Elevation Model 7.5-minute quadrangles, 30-meter resolution
Methods 11

ogy of the watershed is composed of seven formations 

and is dominated by limestone and dolomite; information about each formation is summarized in Gathright 

and Frischmann (1986). The primary formations within 

the watershed include the Martinsburg Formation (calcareous slate, argillite, and sandstone), Beekmantown 

Group (limestone and dolomite), New Market Limestone (limestone with dolomite beds near the base), 

Lincolnshire Formation (cherty limestone), Oranda 

Formation (limestone and calcareous shale), and Edinburg Formation (limestone and calcareous shale). Karst 

features are evident in portions of the watershed. Alluvial material (composed of unconsolidated fine sand, 

silt, and minor clay) is present in portions of the floodplain adjacent to Blacks Run. 

The soils of the Blacks Run watershed have been 

described thoroughly (Hockman and others, 1982) and 

are best classified as derived from the parent material 

from which they were formed. Most of the soil in the 

watershed has formed from the residuum of limestone, 

dolomite, and calcareous shale. Three soil assemblages 

have been identified in this category. The 

Frederick-Lodi-Rock outcrop assemblage consists of 

deep, well-drained, silt loam soils with limestone or 

dolomite outcrop areas. The Endcav-Carbo-Rock 

outcrop assemblage consists of deep and moderately 

deep, well-drained, silt loam soils; sinkholes and 

limestone outcrops are common in this assemblage. 

The Chilhowie-Edom assemblage consists of deep to 

moderately deep, well-drained, silt loam or silty clay 

loam soils with occasional bedrock outcrops. On 

floodplains and terraces, soils have formed in the 

alluvial or colluvial material. Although not extensive 

within the watershed, these soils are part of the 

Monongahela-Unison-Cotaco assemblage, which 

consists of deep, well-drained or moderately well 

drained soils. Generally these soils consist of fine 

sandy loam soils, although some soils are cobbly.

Most water-quality data for this study were collected from Blacks Run below the bridge at Route 704 

(Cecil Wampler Road, station number 01621470); this 

site also is a DEQ ambient water-quality sampling station. Five additional sampling stations (continuum 

sampling sites) along Blacks Run were at Route 753 

(Liberty Street, station number 01621395), Water 

Street (station number 01621397), Route 726 (Stone 

Spring Road, station number 01621410), Route 679 

(Pleasant Valley Road, station number 01621425), and 

Route 988 (station number 01621440).

METHODS

Water-sample collection for bacteria

Intensive streamwater sampling at the ambient 

water-quality sampling station of each watershed was 

done to provide an understanding of the temporal patterns in fecal coliform concentrations and the specific 

sources of these bacteria at each sampling site. Streamwater samples were collected over a wide range of 

hydrological conditions. Low-flow samples were collected from each stream approximately every 6 weeks, 

and approximately 4 of these low-flow samplings in 

each watershed were performed on the recession limbs 

of storm events. Typically, between four and eight 

depth-integrated samples were collected at each sampling site during each low-flow sampling. Width integration was accomplished by sampling at three locations across the width of the stream (the center of the 

channel and approximately halfway to each stream 

bank). The depth-integrated samples were collected at 

5-minute intervals, providing time integration during 

each sampling. Five storm events were sampled on 

each stream. During each storm event, at least 10 water 

samples were collected from approximately the center 

of the streamflow. When possible, the storm samples 

were collected such that the first three samples were 

collected on the rising limb of the hydrograph, the next 

four samples were collected around the peak in the 

hydrograph, and the last three samples were collected 

on the falling limb of the hydrograph (fig. 5). 

All samples were collected using sterile, 160-ml, 

narrow-mouth, borosilicate glass bottles. The samples 

were collected from the stream using the hand-dip 

method or a weighted-bottle sampler, depending on the 

site and flow conditions. Samples were immediately 

chilled on ice and processed in the field within 6 hours 

of collection.

Continuum sampling sites were established at 2- to 

4-mi intervals along each of the three stream reaches, 

resulting in a total of four or five continuum sites on 

each reach. These continuum sites were sampled at various times during this study to evaluate whether the 

intensive sampling at the ambient water-quality sampling station represented the entire watershed. Each 

continuum sample was collected as a single, 

depth-integrated sample from the approximate center 

of the streamflow.
12 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

Synoptic samples of Accotink Creek were collected 

on June 5, 2000, following a major storm event. Various storm drains, major stream tributaries, and main 

channel sites were sampled to determine whether the 

entire watershed was contributing fecal coliform 

bacteria to the stream. Rhodamine WT dye was 

injected into the stream headwaters, and synoptic samples were collected while moving downstream at a rate 

that was consistent with the stream velocity and the 

injected dye. A single water sample (a grab sample) 

from the approximate center of the streamflow was collected from each sampling site. During this synoptic 

survey, a consistent water parcel was sampled as it traveled from the headwaters to the stream gage.

Supporting field measurements

Streamwater discharge and field water-quality 

parameters (pH, turbidity, dissolved oxygen concentration, water temperature, and specific conductance) 

were measured during the collection of each of the 

water samples for bacteria enumeration. Discharge 

measurements were made following standard USGS 

methods (Rantz and others, 1982). All field parameters 

were determined in accordance with the standard methods of the USGS (Wilde and Radke, 1998). The pH, 

water temperature, and specific conductance were measured using a YSI Model 63 handheld field meter. The 

dissolved oxygen concentration was measured using a 

YSI Model 95 handheld field meter. Turbidity was 

determined using a HACH 2100P handheld portable 

turbidimeter. All meters were calibrated (or quality 

assured, as appropriate) at the start of each field day, in 

accordance with the manufacturers’ instructions. Specific conductance, dissolved oxygen concentration, pH, 

and water temperature were measured in situ by positioning the probes in the center (or as close as possible 

to the center) of the streamflow. Turbidity was measured on aliquots obtained from the water samples that 

were processed for bacteria.

Fecal coliform enumeration

All samples for the enumeration of fecal coliform 

bacteria were collected and processed according to 

USGS standard methods (Myers and Sylvester, 1997). 

Figure 5. Storm-flow sampling design for bacterial source tracking study in Accotink Creek, Blacks Run, and Christians Creek watersheds, Virginia.

1,000

500

600

700

400

300

200

100

800

900

0

DISCHARGE, IN CUBIC FEET PER SECOND

0 5 10 15 20 25

TIME SINCE BEGINNING OF RAINFALL EVENT, IN HOURS
Methods 13

Water samples were processed in the field by membrane filtration (using gridded, 0.7-μm pore size membrane filters), and filters were incubated on a media of 

m-FC broth. Through this technique, fecal coliform 

bacteria are defined operationally as organisms that 

produce blue colonies in whole or in part after incubation for 18 to 22 hours at 44.5 ± 0.2oC. A range of sample dilutions was always prepared in an effort to have at 

least one filter with colonies in the ideal counting range 

(20-60 colonies). The filter apparatus, bench tops, and 

necessary equipment were sterilized between the processing of each water sample. Start and end sample 

blanks were processed to ensure that the equipment 

initially was sterile, and that between-dilution rinsing 

procedures were adequate. Replicates were processed 

on 6 percent of the samples. After incubation, fecal 

coliform colonies were counted and the concentration 

of bacteria in the streamwater sample was calculated 

(as col/100 mL) based on the volume of filtered 

sample.

E. coli enumeration

About 150 fecal coliform samples (approximately 

50 from each watershed) also were enumerated for 

Escherichia coli (E. coli) concentrations. E. coli were 

enumerated following standard USGS methods (Myers 

and Sylvester, 1997). Water samples were processed in 

the field by membrane filtration (using gridded, 

0.45-μm pore size membrane filters), and filters were 

incubated on m-TEC agar. Through this technique, E. 

coli bacteria are defined operationally as organisms 

that produce yellow or yellow-brown colonies after 

resuscitation at 35.0 ± 0.5oC for 2 hours and incubation 

for 22 to 24 hours at 44.5 ± 0.2oC. A range of sample 

dilutions was always prepared in an effort to have at 

least one filter with colonies in the ideal counting range 

(20-80 colonies). The filter apparatus, bench tops, and 

necessary equipment were sterilized between the processing of each water sample. Start and end sample 

blanks were processed to ensure that the equipment 

initially was sterile, and that between-dilution rinsing 

procedures were adequate. After incubation, E. coli

colonies were counted and the concentration of the 

streamwater sample was calculated (as col/100 mL) 

based on the volume of filtered sample.

A paired comparison of fecal coliform and E. coli

concentrations was performed to verify that E. coli

were the primary component of the fecal coliform bacteria that were observed in the streams. This verification was important because the ribotyping was performed on E. coli, and the Commonwealth of Virginia 

determined the water quality of streams and rivers on 

the basis of a fecal coliform standard. A strong correlation is present between fecal coliform and E. coli concentrations (fig. 6); most of the fecal coliforms collected in these three streams (67 percent) were E. coli. 

These results justify the use of E. coli bacteria for 

ribotyping even though the water-quality standard is 

based on fecal coliform bacteria.

Bacterial source tracking

Ribotyping was selected as the BST technique for 

this study because it offered definitive source identification and produced results that should be applicable to 

detailed TMDL development. Dr. Mansour Samadpour’s Microbial Source Tracking Laboratory at the 

University of Washington (UWMSTL) performed the 

bacterial source tracking for all samples in this study. 

Although the specific application to field-based source 

identification is relatively new, ribotyping is a 

well-established tool in molecular biology (Tarkka and 

others, 1994; Schalch and others, 1997; Dalla-Costa 

and others, 1998; Samadpour, 2001). Conceptually, 

ribotyping is successful for this application because 

individual E. coli strains generally are host-species specific—only infrequently does an E. coli strain colonize 

a foreign host species. Subtle genetic differences are 

present among E. coli strains, and ribotyping is able to 

characterize these differences. After isolating and characterizing an E. coli strain from an unknown source,

Figure 6. Relation of fecal coliform and E. coli concentrations in water 

samples collected March 1999 through October 2000 in the Accotink Creek, 

Blacks Run, and Christians Creek watersheds, Virginia.

E. coli concentration = 0.67 (Fecal coliform concentration)

R2

= 0.96

100

1,000

10,000

100,000

1,000,000

100 1,000 10,000 100,000 1,000,000

FECAL COLIFORMS, IN COLONIES PER 100 MILLILITERS

E. COLI, IN COLONIES PER 100 MILLILITERS

Regression line
14 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

the strain is compared with a known source database 

(developed from the feces of potential source animals) 

to identify the source of the E. coli. The ribotyping 

technique makes use of the portion of the E. coli

genome that codes for the production of ribosomal 

RNA (ribonucleic acid). This portion of the E. coli

genome is believed to be stable and intolerant of 

genetic mutations. Consequently, individual E. coli

strains should maintain the same genes for ribosomal 

RNA production over many generations, and the occurrence of each E. coli strain can be tracked over 

extended time periods.

Standard microbiological and molecular biology 

techniques were used in the ribotyping analysis. The 

following is a brief description of the steps used in the 

ribotyping procedure: 

1. Isolation of E. coli bacteria: For each water sample, a single fecal coliform plate was sent to the 

UWMSTL, where it was logged into the tracking 

system. Between 3 and 5 E. coli colonies were isolated from each fecal coliform plate. Colonies were 

cultured on MacConkey Agar following standard 

techniques and confirmed using biochemical tests 

(indole production from tryptophane, and lack of 

growth on a citrate media).

2. Preservation of pure cultures: Isolated E. coli colonies were stored by freezing at –80oC in a nutrient 

broth that contained 15-percent glycerol.

3. Isolation of genetic material: Isolated E. coli colonies also were cultured on a nutrient medium for 

isolation of their genetic material. Cells were collected from the nutrient medium and lysed (broken 

open). After various cleanup and extraction steps, 

the free DNA material was isolated from the 

remainder of the cellular material. 

4. Digestion of the DNA material using restriction 

enzymes: The isolated DNA material was digested 

(cut into fragments of variable length that 

depended on the specific base sequence that the 

enzyme recognized) in separate reactions using a 

pair of restriction enzymes (EcoRI and PvuII). 

Each enzyme produces a different, but highly specific digestion of the DNA. 

5. Gel electrophoresis to separate the digested DNA 

material: The DNA fragments were loaded into an 

agarose gel and an electrical field was applied to 

the gel. Because the DNA fragments are negatively 

charged, the induced current causes them to 

migrate away from the negative electrode; the agarose gel is sufficiently permeable that the small 

DNA fragments migrate faster than the larger fragments. After 17 hours, the DNA fragments become 

separated according to the size of the fragment and 

the current is discontinued. One specific E. coli

isolate (labeled isolate #3915) was included with 

every gel to allow size comparisons among individual gels. Following electrophoresis, the DNA fragments in the gel were stained with ethidium bromide (which fluoresces under an ultraviolet light 

source), and the gel was placed under an ultraviolet 

light to ensure that complete digestion occurred 

and that the electrophoresis was successful. If 

digestion and electrophoresis are successful, a fluorescent band of DNA will generally extend from 

the lower edge of the gel (where the DNA fragments were initially loaded) to the upper edge of 

the gel (near the positive electrode).

6. Transfer of the DNA fragments from the agarose 

gel onto a nylon membrane: Once electrophoresis 

was completed, the DNA material was manipulated 

further before being transferred onto a nylon membrane. First, the DNA fragments were cut up further (using hydrochloric acid) to allow an easier 

transfer from the gel onto the paper. Second, the 

DNA was denatured (using sodium hydroxide) into 

single strands to allow recombination with the gene 

probe. Neither of these treatments affected the 

positioning of the DNA within the gel. After these 

two manipulations, the single-stranded DNA fragments were transferred from the agarose gel onto 

the nylon membrane. This procedure is known as 

the Southern blot procedure. After the transfer was 

complete, the nylon membrane was air dried and 

baked to fix the single-stranded DNA fragments to 

the membrane.

7. Hybridization with the radiolabeled cDNA probe:

The radiolabeled cDNA probe was prepared by 

extension of random hexanucleotide primers. The 

probe and the nylon membrane then were combined in a hybridization solution, and the probe 

was given time to hybridize, or bind with any complementary, single-stranded DNA fragments on the 

nylon membrane. Following hybridization, the 

nylon membrane was washed to remove any 

non-specific binding of probe material and then 

allowed to dry. Only regions containing 

single-stranded DNA complementary to the cDNA 

probe retained the radioactive label.
Methods 15

8. Generation of the autoradiograph: The dry membranes were exposed to X-ray films; the hybridized 

regions appear as dark bands on the radiograph 

(fig. 7). This specific banding pattern is the 

“ribotype” for a particular E. coli isolate.

9. Comparison of the unknown E. coli banding pattern to the known-source library of patterns: The 

unknown ribotype was compared to the 

known-source library (described below) to see if 

the unknown pattern matched a source that was 

already sampled. Analysis and identification of the 

unknown isolate banding pattern was performed by 

assigning a numerical value to each ribotype based 

on the distance between bands. Bands that were 

more than 3 mm apart were counted as single 

bands, whereas bands that were within 3 mm of 

each other were counted as double or triple bands 

(for example, two bands that were closer than 3 

mm to each other were designated a “2” and three 

bands with 3 mm or less between each band were 

designated a “3.” In this manner, each banding pattern was assigned a specific numeric value. Two 

isolates with the same numeric value but different 

banding patterns (because the actual bands may be 

shifted and not identical) were assigned letters to 

differentiate the two ribotypes; for example, 

2122111A and 2122111B would identify two isolates with similar but slightly offset banding patterns. Isolates with the same numeric values for 

their ribotypes were deemed to be members of the 

same ribogroup. The known-source library of 

ribotype patterns was stored in an electronic database that also included information on the animal 

source from which each known isolate was 

obtained. Unknown isolates were queried against 

this database, based on the numeric value. If an 

unknown isolate had the same numeric value as 

any in the known-source library, the unknown 

ribotype was compared directly to all the 

known-source isolates that were members of this 

particular ribogroup. The unknown isolate was 

identified only if the banding pattern of the 

unknown isolate visually matched an isolate in the 

library for both the restriction enzymes. Any 

unknown isolate that did not match a sample in the 

known source library was labeled “unknown.”

Figure 7. Example of the banding patterns produced by the ribotyping procedure. Each lane represents the pattern 

generated by a single E. coli isolate.

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

LANE
16 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

Source-sample collection and source library 

development

A source-sample library is necessary for a successful source tracking study. The source-sample library 

provides a set of known ribotype patterns with which 

the unknown isolates can be compared and identified. 

The extensive source library at the UWMSTL contained approximately 50,000 isolates. In addition, a 

site-specific source library was developed for this study 

by collecting known-source fecal samples from most of 

the potentially contributing animal sources in each of 

the three watersheds studied. Fresh fecal samples (of 

known origin) were collected from farms, animal shelters, veterinary clinics, animal rehabilitation centers, 

sewage-treatment plants, forested areas, and public 

parks. These fecal samples were collected aseptically, 

placed in sterile specimen containers, labeled by 

source, and sent by overnight delivery to the 

UWMSTL. At the laboratory, a single E. coli isolate 

was cultured from each fecal sample, ribotyped, and 

added to the source-library database. 

PATTERNS AND SOURCES OF FECAL 

COLIFORM BACTERIA

Overview of the water samples collected

A total of 605 water samples was collected from the 

three study streams during this investigation. The distribution of the total number and the type of water samples collected are presented in table 2. Approximately 

two-thirds of the samples from the ambient waterquality sampling stations in each watershed were collected during low-flow conditions; the remaining 

one-third of all samples were collected during 

storm-flow periods. The collection of water samples 

during both low-flow and storm-flow periods is critical 

for accurately describing both bacteria concentrations 

and bacteria sources in a surface-water system. Continuum samples were also collected to investigate the spatial patterns of the fecal coliform concentrations along 

the length of each study stream. 

Fecal coliform analyses

Spatial patterns in the fecal coliform concentrations

The continuum streamwater samples provided evidence that the fecal coliform concentrations observed 

at the ambient water-quality sampling station of each 

stream were reflective of the water-quality conditions 

for the entire stream (table 3). Although concentrations 

of fecal coliforms were variable among continuum sites 

on a given day, the streamwater quality (relative to the 

water-quality standard) generally was consistent 

among sites; if the water-quality standard was violated 

at the ambient water-quality sampling station, then the 

standard typically was violated at the other continuum 

sampling sites on that day. Similarly, if the waterquality standard was met at the ambient water-quality 

sampling station, then the other continuum sampling 

sites also were generally in compliance with the standard. Several of the continuum samples had extremely 

elevated fecal coliform concentrations (Accotink Creek 

on June 6 and August 8, 2000; Blacks Run on March 

22, July 22, September 5, and October 4, 1999). All six 

of these sampling events were performed under 

storm-affected flow conditions (there had been appreciable rainfall within the past 48 hours and the flow 

was still receding). These storm-affected samples provided evidence that the fecal coliform concentrations 

increase during storm-flow periods. Another Accotink 

Creek sampling event on August 11, 1999, is of interest 

because it occurred during extended drought conditions 

and the stream had been reduced to a series of disconnected pools; the samples from these disconnected

Watershed

Number of samples collected

Low flow Storm flow Continuum Total

Accotink Creek 104 53 36 193

Christians Creek 104 66 18 188

Blacks Run 99 56 69 224

Table 2. Number and type of streamwater samples collected from March 1999 through 

October 2000 in three watersheds in Virginia
Patterns and Sources of Fecal Coliform Bacteria 17

Accotink Creek watershed

Continuum

sample

number

Station

number

Fecal coliform concentration

(col/100mL)

Sampling date

3/18/99 8/11/99 6/6/00a 8/8/00a

1 01653900 320 190 38,000 13,000

2 01653985 200 25 18,000 15,000

3 01653995 50 54 23,000 17,000

4 01654000b 73 37 13,000 13,000

5 01654520 64 42 – 9,300

Christians Creek watershed

Continuum

sample

number

Station

number

Fecal coliform 

concentration

(col/100mL)

Sampling date

3/25/99 7/27/99 8/1/00

1 01624615 5 71 7

2 01624620 87 1,500 300

3 01624660 230 2,000 3,800

4 01624700 23 6,400 1,900

5 01624800b 15 790 1,800

6 01624900 9 140 830

Blacks Run watershed

Continuum

sample

number

Station

number

Fecal coliform concentration

(col/100mL)

Sampling date

3/22/99a 7/22/99a 8/19/99 9/5/99a 10/4/99a 11/17/99 12/17/99 1/22/00 2/25/00 3/28/00 4/27/00 5/13/00 8/15/00

1 01621395 290,000 – – 86,000 2,300 – – – 16 200 450 – –

2 01621397 – 23,000 760 62,000 4,600 300 1,100 20,000 120 770 340 2,000 6,000

3 01621410 100 54,000 610 41,000 4,300 69 160 – 26 42 170 770 520

4 01621425 400 81,000 820 22,000 2,300 33 110 13 80 130 610 1,700 2,000

5 01621440 2,000 39,000 94 21,000 1,100 10 18 10 13 160 73 200 380

6 01621470b 2,200 7,200 22,000 65,000 6,300 410 6,000 20 390 180 61 580 700

Table 3. Fecal coliform concentrations of the continuum samples in three watersheds in Virginia, 1999-2000

[Location of stations on figures 2-4; col/100 mL, colonies per 100 milliliters; –, no sample collected]

a Storm-affected sample (rain had occurred in the last 48 hours and flow was receding) b Sampling station is co-located with a stream gage
18 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

pools had some of the lowest fecal coliform concentrations that were observed during the study.

The synoptic sampling of Accotink Creek on June 

6, 2000, provided further evidence that the entire 

watershed was contributing fecal coliforms (table 4). 

This synoptic sampling was performed immediately 

following a storm event and included samples from 

various storm drains, major stream tributaries, and 

main channel sites (all samples were collected while 

moving in the downstream direction). All sampled 

storm drains and stream tributaries had elevated concentrations of fecal coliform bacteria, and all samples 

collected during this synoptic survey exceeded the 

Commonwealth’s instantaneous water-quality standard 

for fecal coliform bacteria (1,000 col/100 mL). However, because these samples were collected at different 

times and on different portions of the storm recession 

(while the water quality of the entire stream system was 

changing rapidly), direct comparisons of fecal coliform 

concentrations among sites would not be meaningful. 

For example, these data do not support the conclusion 

that the fecal coliform contributions from Daniels Run 

were greater than the contributions from Coon Branch 

because these two samples were collected approximately 9 hours apart and on different portions of the 

hydrograph. Rather, one could conclude that elevated 

concentrations of fecal coliform bacteria occurred 

throughout the watershed and that all areas sampled 

contributed to these elevated concentrations.

Temporal patterns in the fecal coliform concentrations

Seasonal patterns were evaluated in the fecal 

coliform concentrations at each ambient water-quality 

sampling station. Water samples were collected over a 

20-month period, with 15 sampling events at each site 

during low-flow periods. Between four and eight water 

samples were collected during each low-flow sampling 

event, and these low-flow fecal coliform concentrations 

are summarized (fig. 8). For some of the low-flow sampling events, stream discharge records and meteorological data indicated that the streamflow was receding 

and that rain had fallen within the last 48 hours. These 

recession-flow samples (identified in figure 8) represent a subset of the low-flow samples. Most of the 

low-flow samples, however, were not collected under 

periods of recession flow, and this other subset of 

low-flow samples is referred to as base-flow samples. 

In Accotink Creek, base-flow fecal coliform concentrations were generally below the instantaneous 

water-quality standard of 1,000 col/100 mL (fig. 8); 

however, the recession-flow samples occasionally 

exceeded the water-quality standard. The recession-flow fecal coliform concentrations were significantly elevated relative to the base-flow fecal

Main channel

station

Fecal coliform

(col/100mL)

Stream tributary

sampling station

Fecal coliforma

(col/100mL)

Storm-drain

sampling

station number

Fecal coliform

(col/100mL)

Above Daniels Run 33,000 Daniels Run 100,000 1 21,000

01653900 38,000 Hunters Run 22,000 2 31,000

01653985 18,000 Bear Branch 22,000 3 10,000

01653995 23,000 Long Branch 30,000 4 10,000

01654000 13,000 Crook Branch 18,000 5 2,000

Coon Branch 13,000

Turkey Run 1,100

Table 4. Fecal coliform concentrations of water samples collected in the Accotink Creek watershed, Virginia, during 

synoptic sampling, June 6, 2000

[col/100 mL, colonies per 100 milliliters; samples collected and stations listed in downstream order; storm-drain station 

numbers increase in the downstream direction]

a Upstream sites were sampled immediately following a storm; more downstream sites were sampled later on the recession curve of the storm 

hydrograph
Patterns and Sources of Fecal Coliform Bacteria 19

Figure 8. Fecal coliform concentrations during low-flow sampling of Accotink Creek (A), Blacks Run (B), and Christians Creek (C) watersheds, 

Virginia, 1999-2000.

75th Percentile

Median

25th Percentile

Concentration exceeding upper or lower quartile by 

more than 1.5 times the interquartile range

Largest concentration value less than or equal to the 

upper quartile plus 1.5 times the interquartile range 

Smallest concentration value greater than or equal to the 

lower quartile minus 1.5 times the interquartile range 

EXPLANATION

Instantaneous fecal coliform water-quality standard

Instantaneous fecal coliform water-quality standard

Instantaneous fecal coliform water-quality standard

Recession-flow sample date (precipitation in previous 

48 hours and flow was receding)

10

100

1,000

10,000

FECAL COLIFORMS, IN COLONIES PER 100 MILLITERS

100

1,000

10,000

100,000

10

100

1,000

10,000

5/27/99

10/2/00

7/7/99

8/17/99

9/27/99

11/10/99

12/21/99

2/3/00

3/24/00

5/3/00

4/13/99

5/31/00

7/11/00

8/10/00

9/21/00

10/13/99

11/22/99

1/4/00

3/1/00

3/30/00

5/10/00

6/14/00

7/18/00

8/17/00

4/27/99

9/26/00

10/4/00

6/9/99

7/20/99

8/25/99

8

9/27/00

10/5/00

/28/00

8/3/00

3/30/00

5/10/00

6/20/00

3/1/00

1/18/00

12/6/99

10/25/99

7/2

9/13/99

8/99

6/16/99

5/5/99

SAMPLING DATE

(A)

(B)

(C)

8/3/00
20 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

coliform concentrations (p < 0.05 using a Wilcoxon 

rank-sum test). The timing of the collection of some of 

the recession-flow samples makes a seasonal evaluation difficult; however, there appeared to be a slight 

seasonality with slightly lower fecal coliform concentrations during the winter and slightly higher concentrations during the warmer months. Pronounced 

seasonality in the fecal coliform concentrations was not 

expected in Accotink Creek because the land-use practices and potential fecal coliform sources in the watershed can be considered constant throughout the year.

Low-flow fecal coliform concentrations in Blacks 

Run were elevated relative to the Commonwealth’s 

water-quality standard (fig. 8). Similar to Accotink 

Creek, the recession-flow water samples had fecal 

coliform concentrations that were significantly higher 

than those observed during base-flow conditions 

(p < 0.05 using a Wilcoxon rank-sum test). More than 

half of the base-flow water samples had fecal coliform 

concentrations that exceeded the 1,000 col/100 mL 

fecal coliform standard. A seasonal pattern was present 

that was similar to, but more pronounced than the one 

observed in Accotink Creek. The highest base-flow 

fecal coliform concentrations occurred during the summer and into the fall. During the winter, fecal coliform 

concentrations decreased to a minimum and then 

increased during the spring. This seasonal pattern is 

consistent with the animal management practices in the 

watershed. Livestock numbers typically are greatest 

during the summer and fall, and during these warm 

months the animals (particularly cattle) spend more 

time closer to and sometimes wading into the stream. 

This increased association of animals with the stream 

likely results in both direct deposition of feces into the 

stream and deposition of feces closer to the stream than 

during other times of the year. In addition to animal 

management practices, it also is possible that seasonally different fecal coliform survival rates (greater bacteria survival during the warm summer, relative to the 

cold winter, for example) may have affected these 

observed fecal coliform concentrations and contributed 

to the observed seasonal patterns.

Low-flow fecal coliform concentrations in Christians Creek also demonstrated a seasonal pattern 

(fig. 8). Approximately half of the base-flow water 

samples had fecal coliform concentrations that 

exceeded the Commonwealth’s water-quality standard. 

Recession-flow samples had fecal coliform concentrations that were significantly elevated relative to the 

base-flow samples (p < 0.05 using a Wilcoxon 

rank-sum test). The seasonal variation in the Christians 

Creek fecal coliform concentrations was more pronounced and followed the same pattern as at Blacks 

Run and Accotink Creek. The highest base-flow fecal 

coliform concentrations occurred during the warm 

summer months, concentrations decreased through the 

fall, reached a minimum during the winter, and then 

concentrations increased through the spring. This pattern again is consistent with the animal practices in the 

watershed (increased animal density and activity 

around the streams during the hot summer months) and 

possible seasonal differences in survival rates of fecal 

coliform bacteria. Similar seasonal patterns have been 

described in other studies of fecal coliform concentrations and loads (Christensen and others, 2001; 

Baxter-Potter and Gilliland, 1988). 

Fecal coliform concentrations were also monitored 

during five storm events on each study stream. At least 

10 water samples were collected during each storm 

event, and as possible, the entire storm hydrograph (rising limb, plateau, and falling limb) was sampled. The 

fecal coliform concentrations observed during these 

storm events (fig. 9) were significantly elevated 

(p < 0.05 using Wilcoxon rank-sum test) relative to the 

observed base-flow fecal coliform concentrations (the 

recession-flow samples were not included for this analysis), and the water-quality standard was usually 

exceeded during these storm events. A large range of 

concentrations was observed during the individual 

storms because of the comprehensive sampling over the 

entire hydrograph. Peak fecal coliform concentrations 

observed during storm events on each study stream 

were 340,000 col/100 mL in Accotink Creek; 

260,000 col/100 mL in Blacks Run; and 

730,000 col/100 mL in Christians Creek. These elevated fecal coliform concentrations during storm events 

were anticipated on the basis of the results of previous 

studies (Christensen and others, 2001; Bolstad and 

Swank, 1997). In other studies, these elevated 

storm-flow concentrations have been interpreted as a 

combination of a flushing response (whereby fecal 

coliform bacteria that were deposited near the stream 

are washed off the land surface and into the stream) and 

a re-suspension of streambed sediments containing 

fecal coliform bacteria (Hunter and others, 1992; 

McDonald and Kay, 1981). Similar mechanisms likely 

were responsible for the storm-flow fecal coliform concentrations observed in these study streams, although 

other sources (including cross-pipes, failing septic sys
Patterns and Sources of Fecal Coliform Bacteria 21

Figure 9. Fecal colifrom concentrations during storm-flow sampling of Accotink Creek (A), Blacks Run (B), and Christians Creek (C) watersheds, 

Virginia, 1999-2000.

Instantaneous fecal coliform water-quality standard

Instantaneous fecal coliform water-quality standard

Instantaneous fecal 

coliform water-quality 

standard

100

1,000

10,000

100,000

1,000,000

5/24/99 8/14/99 9/9/99 9/16/99 6/5/00

100

1,000

10,000

100,000

1,000,000

5/8/99 9/16/99 11/2/99 1/10/00 6/14/00

100

1,000

10,000

100,000

1,000,000

9/5/99 4/25/00 11/1/99 3/20/00 6/28/00

FECAL COLIFORMS, IN COLONIES PER 100 MILLILITERS

(A)

(B)

(C)

SAMPLING DATE

75th Percentile

Median

25th Percentile

Concentration exceeding upper or lower quartile by 

more than 1.5 times the interquartile range

Largest concentration value less than or equal to the 

upper quartile plus 1.5 times the interquartile range 

Smallest concentration value greater than or equal to the 

lower quartile minus 1.5 times the interquartile range 

EXPLANATION
22 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

tems, and leaking or overflowing sewer lines) also may 

have contributed during storms.

Overall, the storm-flow responses of the fecal 

coliform bacteria and the supporting water-quality 

parameters were consistent among the three study 

streams and with the responses observed in previous 

studies. The data from the intensive sampling of the 

storm events are presented as a series of chemographs 

(figures demonstrating the time-course evolution of the 

stream-water composition during a storm event); a single, representative storm event from each study stream 

is presented (fig. 10). In general, the data demonstrated 

an increased fecal coliform concentration on the rising 

limb of the storm hydrograph, peak fecal coliform concentrations around the hydrograph peak, and decreased 

fecal coliform concentrations on the falling limb of the 

hydrograph. In a minor variation of this pattern, fecal 

coliform concentrations in Accotink Creek usually 

were slightly decreased during the peak in the 

hydrograph. Data on the supporting water-quality 

parameters (turbidity, specific conductance, pH, and 

dissolved oxygen concentration) were typically collected during storm events at a frequency slightly 

greater than that used for fecal coliforms. Turbidity levels always increased during storm events, generally 

reaching a maximum concentration about the time of 

the peak discharge. Increased turbidity levels are 

reflective of the suspended sediments that enter the 

water column because of surface runoff, re-suspension 

of the streambed sediments, or stream bank erosion 

(Kronvang and others, 1997; Jeje and others, 1991). 

The pH generally decreased slightly during storm 

events in all streams. Declines in pH are commonly 

observed during storms, as relatively more acidic rainfall, runoff, and interflow contributes to the streamflow. 

These acidic contributions consume buffering capacity 

and reduce the overall pH (Whitfield and others, 1993; 

Gburek and Pionke, 1993). As observed in earlier studies (Laudon and Slaymaker, 1997; Caissie and others, 

1996), specific conductance generally decreased during 

storm events–an indication that the new water that was 

added to the stream during the storm had a relatively 

lower specific conductance than what was already resident in the stream. Although the initial runoff (also 

referred to as the “first flush”) from a watershed may 

contain relatively high concentrations of dissolved 

material (and an elevated specific conductance), subsequent runoff and incident rainfall generally are much 

more dilute and result in an overall reduction in the 

streamwater specific conductance during storm events 

(De Boer and Campbell, 1990). Dissolved oxygen concentrations typically decreased during storm events, a 

response that has been observed in other studies (Bolstad and Swank, 1997). This decrease in dissolved oxygen concentrations generally is attributed to rapid 

inputs of readily degraded organic material in the surface runoff, and potentially an increased oxygen 

demand by the re-suspended streambed sediments.

Correlations between fecal coliform concentrations and 

stream-water parameters

Correlations were examined between the observed 

fecal coliform concentrations and the supporting 

streamwater parameters to develop multiple linear 

regression models for predicting fecal coliform concentrations at each of the ambient water-quality sampling 

stations. Parameters considered for these empirical 

models included discharge, specific conductance, turbidity, pH, water temperature, and dissolved oxygen 

concentration. The multiple linear regression models 

were developed using the approach described by Helsel 

and Hirsch (1992). On the basis of their sample distributions, the fecal coliform concentration, discharge, 

and turbidity variables were transformed logarithmically (log base 10) to reduce skew and produce more 

normally distributed residual and partial plots. Best 

subsets regression was used to identify the most promising multiple linear regression models. These candidate models were subsequently screened for significance of all variables, and the best models were 

selected based on a minimized Mallows Cp and maximized adjusted R2. Plots of the model residuals also 

were evaluated to ensure that the residuals were normally distributed and had a constant variance. 

Although best subsets regression is the optimal 

method for developing multiple linear regression models, stepwise multiple linear regression also may be 

used (Helsel and Hirsch, 1992). As confirmation, stepwise multiple linear regressions also were performed 

on the fecal coliform concentration data, and the same 

supporting streamwater parameters were used as independent variables. The stepwise multiple linear regressions identified the same models as those selected 

using the best subsets regression. 

Multiple linear regression models were developed 

for the ambient water-quality sampling station of each 

individual study stream, as well as a combined overall 

model of all three monitoring stations. These models 

predicted fecal coliform concentrations as a function of
Patterns and Sources of Fecal Coliform Bacteria 23

Figure 10. Changes in discharge, fecal coliform concentrations, and supporting water-quality parameters during storm 

events September 9-10, 1999, Accotink Creek (A), September 15-16, 1999, Blacks Run (B), and June 27-29, 2000, 

Christians Creek (C) watersheds, Virginia.

0

200

400

600

800

1,000

1,200

TOTAL HOURS ELAPSED

DISCHARGE AND 10 X RAINFALL

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

FECAL COLIFORM CONCENTRATIONS,

IN COLONIES PER 100 MILLILITERS

Discharge, in cubic 

feet per second

Rainfall, in millimeters

Fecal coliforms

6

6.5

7

7.5

8

8.5

DISSOLVED OXYGEN CONCENTRATIONS,

IN MICROGRAMS PER LITER

60

70

80

90

100

110

120

130

140

SPECIFIC CONDUCTANCE, IN 

MICROSIEMENS PER CENTIMETER

Dissolved oxygen

AT 25 DEGREES CELSIUS

Specific conductance

6.6

6.7

6.8

6.9

7

7.1

7.2

12 18 24 30 36

pH, IN STANDARD UNITS

0

100

200

300

400

500

600

700

800

TURBIDITY, IN NEPHELOMETRIC

TURBIDITY UNITS

pH

Turbidity

(A)
24 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

Figure 10. Changes in discharge, fecal coliform concentrations, and supporting water-quality parameters during storm 

events September 9-10, 1999, Accotink Creek (A), September 15-16, 1999, Blacks Run (B), and June 27-29, 2000, 

Christians Creek (C) watersheds, Virginia—Continued.

(B)

DISCHARGE AND 10 X RAINFALL

FECAL COLIFORM CONCENTRATIONS,

IN COLONIES PER 100 MILLILITERS

DISSOLVED OXYGEN CONCENTRATIONS,

IN MICROGRAMS PER LITER pH, IN STANDARD UNITS

TURBIDITY, IN NEPHELOMETRIC

TURBIDITY UNITS

0

20

40

60

80

100

0

10,000

20,000

30,000

40,000

50,000

60,000

7.6

7.7

7.8

7.9

8

8.1

8.2

8.3

8.4

8.5

8.6

8.7

200

250

300

350

400

450

500

550

600

650

7.8

7.85

7.9

7.95

8

8.05

8.1

8.15

0

50

100

150

200

250

300

350

Discharge, in cubic 

feet per second

Rainfall, in millimeters

Fecal coliforms

Dissolved oxygen

Specific conductance

pH

Turbidity

0 10 20 30 40 50 60

TOTAL HOURS ELAPSED

SPECIFIC CONDUCTANCE, IN 

MICROSIEMENS PER CENTIMETER

AT 25 DEGREES CELSIUS
Patterns and Sources of Fecal Coliform Bacteria 25

Figure 10. Changes in discharge, fecal coliform concentrations, and supporting water-quality parameters during storm 

events September 9-10, 1999, Accotink Creek (A), September 15-16, 1999, Blacks Run (B), and June 27-29, 2000, 

Christians Creek (C) watersheds, Virginia—Continued.

(C)

0 10 20 30 40 50 60 70

TOTAL HOURS ELAPSED

FECAL COLIFORM CONCENTRATIONS,

IN COLONIES PER 100 MILLILITERS

TURBIDITY, IN NEPHELOMETRIC

TURBIDITY UNITS

DISCHARGE AND 10 X RAINFALL

DISSOLVED OXYGEN CONCENTRATIONS,

IN MICROGRAMS PER LITER pH, IN STANDARD UNITS

0

50

100

150

200

250

300

350

0

50,000

100,000

150,000

200,000

250,000

300,000

5

5.5

6

6.5

7

7.5

8

8.5

9

9.5

350

400

450

500

7.7

7.75

7.8

7.85

7.9

7.95

8

8.05

8.1

0

200

400

600

800

1,000

1,200

Discharge, in cubic 

feet per second

Rainfall, in millimeters

Fecal coliforms

Dissolved oxygen

Specific conductance

pH

Turbidity

SPECIFIC CONDUCTANCE, IN 

MICROSIEMENS PER CENTIMETER

AT 25 DEGREES CELSIUS
26 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

(Sample concentration) - (Mean of replicate)

(Mean of replicate) Sample % difference = x 100%

some of the supporting streamwater parameters. In all 

the models, turbidity was identified as the parameter 

that explained the greatest variance and was most significant in the model. In addition to turbidity, parameters such as water temperature, pH, and dissolved 

oxygen also were useful in explaining some of the variability in the fecal coliform concentrations. The regression equations and correlation coefficients for these 

models are:

Accotink Creek:

Blacks Run: 

Christians Creek:

All three streams combined:

where FC represents the fecal coliform concentration, 

 Turb is the turbidity,

 WT is the water temperature, and

 DO is the dissolved oxygen concentration. 

A comparison between the model predictions and 

the observed data for all sites is presented (fig. 11). In 

general, these models explained between 64 percent 

and 88 percent of the observed variability in fecal 

coliform concentrations, depending on the study 

stream. The ability to predict fecal coliform concentrations from these easily measured water-quality parameters is useful, particularly when estimates of fecal 

coliform concentrations are needed quickly (18-22 

hours of incubation are required before fecal coliform 

concentrations can be determined). Additionally, the 

parameters used in these predictive models are easier 

and less expensive to analyze for than fecal coliform; 

this regression approach may be especially useful in 

cases where monitoring cost is a special concern. 

Although it appears that these empirical models can be 

used to predict fecal coliform concentrations, independent verification is needed before these models should 

be applied. After verification, these models would be 

relevant to the conditions and streams in which they 

were developed. Given the variability in the observed 

fecal coliform concentrations (relative to the predicted 

concentrations), these empirical models may be best 

suited for situations that require only an approximate 

fecal coliform concentration, or that call for evaluating 

the likelihood of a water sample exceeding a specific 

water-quality standard or criterion.

Correlations between turbidity and fecal coliform 

concentrations have been observed previously (Christensen and others, 2001; Francy and Darner, 1998). 

Conceptually, the strong relation between fecal 

coliform concentrations and turbidity may result 

because both constituents are “flushed” into the stream 

during storm events (fecal coliforms are transported in 

runoff from parking lots, pastures, fields, and other surfaces; sediments are generally eroded off the land surface and carried into the stream). A distinction must be 

made, however, between this correlation and any inference of causality. Although turbidity is an effective predictor of fecal coliform concentrations, it cannot be 

inferred that the sediments (measured as turbidity) are 

the primary source of the fecal coliforms; rather, it can 

be concluded that conditions that favor elevated fecal 

coliform concentrations also favor elevated turbidity 

levels.

Analysis of replicate fecal coliform enumerations

Knowledge of the variability inherent in the fecal 

coliform enumeration process is important for comparing fecal coliform concentrations of different water 

samples. Replicate fecal coliform enumerations were 

performed on 6 percent of the samples collected (7 

duplicate fecal coliform enumerations and 24 triplicate 

fecal coliform enumerations). The replicate fecal 

coliform enumerations were generally performed as 

multiple analyses of a single water sample (in a few 

cases, paired water samples were collected simultaneously and analyzed as duplicate samples). These replicate enumerations were analyzed using a percent difference calculation, given as:

log[FC] = 1.130 (log[Turb]) + 0.044 (WT) + 1.068

R2 = 0.88 (2)

log[FC] = 0.768 (log[Turb]) - 0.086 (DO) - 0.025 (WT) + 3.825

R2 = 0.68 (3)

log[FC] = 1.314 (log[Turb]) + 0.668 (pH) - 3.908 

R2 = 0.64 (4)

log[FC] = 1.222 (log[Turb]) + 1.688

R2 = 0.71, (5)

(6)
Patterns and Sources of Fecal Coliform Bacteria 27Figure 11. Relations of observed and predicted fecal coliform concentrations as a function of water-quality parameters, from streamwater samples collected March 1

Accotink Creek (A), Blacks Run (B), and Christians Creek (C), and all three streams combined (D). OBSERVED LOG OF FECAL COLIFORM CONCENTRATION, IN COLONIES PER 100 MILLILITERS Predicted log (fecal coliform) = 1.222 (log turbidity)+1.688

R

2 = 0.71

1

2

3

4

5

6

1

2

3

4

5

6

PREDICTED LOG OF FECAL COLIFORM CONCENTRATION, IN COLONIES PER 100 MILLILITERS Predicted log (fecal coliform) = 1.130 (log turbidity) + 0.044 (water temperature) + 1.068

R

2 = 0.88

1 2 3 4 5 6 1 2 3 4 

(A)

(C) 

1:1 agreement between the predicted and observed values

Predicted log (fecal coliform) = 0.768 (log turbidity) - 0.086 (dissolved oxy

R

2 = 0.68

Predicted log (fecal coliform) = 1.314 (log turbidity) + 0.668 (pH) - 3.908

R

2 = 0.64
28 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

The percent difference values for each individual enumeration (n=86) were summarized to evaluate the variability in the fecal coliform enumeration technique. 

The percent difference term was normally distributed, 

with a mean percent difference value of 0.00 percent 

and a standard deviation of 12.2 percent. This normal 

distribution of the percent difference term can be used 

to calculate the probability of observing the specific 

percent difference value that is present between two 

fecal coliform concentrations (Johnson and Bhattacharyya, 1985).

Bacteria sources in the three streams

Samples submitted for source tracking

In performing this BST study, a large number of 

samples were collected over 20 months. Only the water 

samples collected from the ambient water-quality 

sampling station of each study stream were submitted 

for the source-tracking analysis; none of the continuum 

samples were submitted for ribotyping. This source 

tracking design was selected because it allowed the 

development of an understanding of the spatial and 

temporal patterns in fecal coliform concentrations 

throughout each study stream and it provided 

knowledge of the bacteria sources affecting water 

quality at the ambient water-quality sampling station 

for each stream.

Results of the bacterial source tracking

A total of 1,285 unknown E. coli isolates was 

ribotyped from the three watersheds during this investigation (table 5). Overall, 65 percent of those isolates 

were matched to a known-source isolate in the source 

library. Identification of 65 percent of the unknown isolates is considered successful and is consistent with 

previous ribotyping studies (Farag and others, 2001; 

Samadpour and Chechowitz, 1995). The distribution of 

the number and the type of isolates that were ribotyped 

is presented in table 5. About 61 percent of the 

source-tracked isolates were selected from low-flow 

samples, and about 39 percent of all isolates were from 

storm-flow samples. Similarly, about 59 percent of the 

identified E. coli were from low-flow samples, and 41 

percent were from storm-flow samples. The collection 

and identification of E. coli isolates from both low-flow 

and storm-flow periods were important for identifying 

the dominant sources of bacteria in the watersheds. 

Procedures for quantifying and interpreting BST 

data are still being developed; few standard protocols 

exist to handle the complexities of these data and the 

methods used to generate them (Simpson and others, 

2002). As this technology is applied under different 

field settings and as the science of BST matures, more 

uniform approaches may be developed. One unresolved 

issue involves the number of known-source isolates 

that are needed to accurately quantify the distribution 

of bacteria sources. A sample size of about 1,000 E. 

coli isolates represents only a small fraction of the total 

number of fecal coliform bacteria that are transported 

by the three streams. The frequency with which samples should be collected during any BST study is also 

unresolved. More frequent sampling is expensive but 

may be necessary for evaluating seasonal patterns that 

may be present in the bacteria sources that are contributing to a stream. The value of storm-flow sampling is 

unresolved. Point sources are likely to be the primary 

contributors of fecal coliform bacteria to a stream during base-flow conditions, and nonpoint-source contributions likely dominate during storm-flow periods, but 

these patterns have yet to be investigated. There remain 

questions regarding the number of bacteria isolates to 

source-track from each individual water sample. 

Evaluating many isolates from a single water sample

Watershed

Total 

isolates

(percent low flow)

Identified isolates

(percent)

Identified low-flow 

isolates

(percent)

Identified storm-flow 

isolates

(percent)

Accotink Creek 404 (64.6) 279 (69.1) 174 (62.4) 105 (37.6)

Blacks Run 451 (60.1) 285 (63.2) 173 (60.7) 112 (39.3)

Christians Creek 430 (59.5) 274 (63.7) 146 (53.3) 128 (46.7)

Total 1,285(61.3) 838 (65.2) 493 (58.8) 345 (41.2)

Table 5. Number of E. coli isolates ribotyped, and percentage of those isolates from low-flow samples collected from 

three watersheds in Virginia, March 1999 through October 2000. Number (and percentage) of isolates that were 

identified, and the number (and percentage) of identified isolates from low-flow and high-flow samples
Patterns and Sources of Fecal Coliform Bacteria 29

may provide a more detailed understanding of that particular sample, but restrictions in the scope of a study 

may result in fewer water samples collected and 

source-tracked. Although these questions remain unresolved, our intensive sampling over a 20-month period, 

incorporation of low-flow and storm-flow sampling, 

and identification of more than 270 isolates in each 

watershed should allow these data to be treated in a 

semi-quantitative manner and for inferences to be 

drawn regarding the bacteria sources that are impairing 

these three streams. 

Before presenting the bacteria sources that were 

identified in the three watersheds, the unidentified E. 

coli isolates must be considered. Approximately 35 

percent of the isolates were unidentified. These unidentified isolates represent E. coli that were not yet present 

in the known-source library. Based on knowledge of 

the potential fecal coliform contributors in these watersheds and the sources represented in the known-source 

library, the presence of a significant yet unrepresented 

fecal coliform contributor in these watersheds (lions, 

for example) is unlikely. It is likely that the unidentified 

isolates are from sources that are common in these 

watersheds (humans, dogs, and raccoons, for example) 

but that the particular ribotype was not yet included in 

the known-source library. Collection of additional 

known-source isolates likely would reduce the number 

of unidentified isolates. On the basis of the diversity of 

the 50,000-isolate known-source library that was used 

in this study, it is reasonable to assume that the sources 

of the unidentified isolates had a distribution that was 

identical to the source distribution observed in each 

watershed. The implication of this assumption is that 

the identified isolates could be used to describe the 

overall distribution of E. coli sources (and, therefore, 

fecal coliform sources) that impaired each watershed.

The identified bacteria sources in the three watersheds demonstrate that a diverse collection of fecal 

sources contributed to the impairment of each stream 

(fig. 12). Two source categories are discussed in more 

detail. The first source category that was treated differently is poultry, which represents a combination of 

chicken and turkey sources. The ribotyping technique 

sometimes was able to distinguish chickens from turkeys (and the two are labeled separately in figure 12b 

and c); in other cases, an isolate was identified as either 

a chicken or a turkey isolate (in this case, the isolate is 

labeled as poultry). This lack of specificity may have 

occurred for three reasons: (1) identical E. coli were 

found in both birds; (2) different E. coli were found in 

chickens and turkeys, but the ribotyping analysis produced banding patterns that were identical; or (3) the 

ribotype from the source library that matched the 

unknown isolate was identified during the source collection process as poultry litter and did not indicate 

whether the sample was from chickens or turkeys. For 

data-interpretation and watershed-modeling purposes, 

the chicken, turkey, and poultry categories were combined into a total poultry category. The second category 

that was treated differently is avian, a source which was 

identified in all three watersheds. The avian category 

represents E. coli isolates that occurred in multiple bird 

species. Whereas the poultry category is specific to 

chickens and turkeys, the avian category encompasses 

all birds. For data-interpretation and watershedmodeling purposes, this avian category was distributed 

among all the observed bird sources, which included 

geese, ducks, sea gulls, crows, poultry, and swans. 

Quantitatively, it was assumed that the avian component was distributed proportionally, according to the 

occurrence of each individual bird source shown in figure 12. For example, if the goose contribution for an 

individual stream was 25 percent of all the bird sources 

that were identified, then 25 percent of the avian contribution was attributed to geese. In this way, the avian 

contribution was distributed among all the identified 

bird sources.

 After combining the poultry sources and distributing the avian component, the E. coli sources of each 

stream were re-plotted (fig. 13). The plot for each 

stream was arranged from the greatest contributor to 

the least contributor. No single source accounted for 

more than 30 percent of the identified E. coli; a range 

of sources contributed fecal coliforms to all three 

stream systems. In Accotink Creek, the greatest contributors were geese and human sources, followed by 

dogs, ducks, cats, sea gulls, and raccoons (fig. 13a). 

Cattle, poultry, human sources, and dogs were the top 

four sources in both Blacks Run and Christians Creek 

(fig. 13b and c). Cats also were an important source in 

Blacks Run, whereas horses and deer were additional 

sources to Christians Creek. All other observed sources 

were minor, providing less than 5 percent of the total 

source observed in these streams. Although they were 

independently considered minor, these minor sources 

may be cumulatively important to the overall water 

quality in these streams.

The bacteria-source data can also be grouped by 

their general animal categories (humans, pets, waterfowl, wildlife, and agricultural; fig. 14). Accotink
30 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

Figure 12. Distribution of the bacteria isolates that were identified in streamwater samples collected from 

March 1999 through October 2000 in Accotink Creek (A), Blacks Run (B), and Christians Creek (C), Virginia.

0

5

10

15

20

25

Human

Goose

Avian

Dog

Cat

Duck

Raccoon

Sea gull

Rodent

Cattle

Deer

Rabbit

Muskrat

Sheep

Ground hog

Fox

Horse

Opossum

Poultry

Coyote

Bear

Swan

0

5

10

15

20

25

30

35

Cattle

Human

Poultry

Avian

Dog

Cat

Raccoon

Turkey

Horse

Deer

Opossum

Sheep

Rodent

Duck

Coyote

Goose

Sea gull

Pig

Crow

Rabbit

Chicken

0

5

10

15

20

25

Cattle

Avian

Human

Dog

Horse

Deer

Turkey

Poultry

Cat

Raccoon

Duck

Goose

Sea gull

Fox

Crow

Chicken

Rodent

Opossum

Coyote

Beaver

Skunk

Goat

PERCENT CONTRIBUTION PERCENT CONTRIBUTION PERCENT CONTRIBUTION

(A)

(B)

(C)

IDENTIFIED BACTERIA SOURCE

N = 279 isolates

N = 285 isolates

N = 274 isolates
Patterns and Sources of Fecal Coliform Bacteria 31

Figure 13. Distribution of the bacteria isolates that were identified in streamwater samples collected from 

March 1999 through October 2000 in Accotink Creek (A), Blacks Run (B), and Christians Creek (C), Virginia, 

after combining the poultry sources and distributing the avian source.

(A)

(C)

(B)

0

5

10

15

20

25

30

Goose

Human

Dog

Duck

Cat

Sea gull

Raccoon

Rodent

Cattle

Deer

Rabbit

Muskrat

Poultry

Swan

Sheep

Ground hog

Fox

Horse

Opossum

Coyote

Bear

0

5

10

15

20

25

30

Cattle

Poultry

Human

Dog

Cat

Raccoon

Horse

Deer

Goose

Opossum

Duck

Sheep

Rodent

Sea gull

Coyote

Pig

Crow

Rabbit

0

5

10

15

20

25

30

PERCENT CONTRIBUTION PERCENT CONTRIBUTION PERCENT CONTRIBUTION

Cattle

Poultry

Human

Dog

Cat

Horse

Deer

Raccoon

Goose

Duck

Sea gull

Crow

Fox

Opossum

Rodent

Coyote

Beaver

Skunk

Goat

IDENTIFIED BACTERIA SOURCE

N = 279 isolates

N = 285 isolates

N = 274 isolates
32 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

Creek was dominated by waterfowl sources (geese, 

ducks, sea gulls, and swans), followed by almost equal 

contributions from human sources and pets (dogs and 

cats). Wildlife also made an important contribution to 

Accotink Creek, whereas agricultural sources were relatively minor. Both Blacks Run and Christians Creek 

were dominated by agricultural sources, followed by 

contributions from human sources, pets, and wildlife. 

Both Blacks Run and Christians Creek also had relatively minor contributions from waterfowl. In addition 

to the differences in the general categories that contributed to the impairment of each stream, the data indicate 

that a range of sources contributed fecal coliforms to 

each stream; no one group of sources accounted for 

more than 60 percent of the identified E. coli in these 

stream systems.

Comparison of the BST results (figs. 13 and 14) 

with the land use of each watershed (fig. 15) demonstrates relations between the dominant activities within 

each watershed and the observed bacteria sources. The 

land use of each watershed can be used to infer the 

source category that would be expected to contribute 

bacteria to these three streams. Although information 

about the land use can aid in verifying the presence of 

an observed source, the BST data from this study do 

not provide information on the specific mechanisms by 

which the bacteria are entering these streams.

The Accotink Creek watershed is primarily urban, 

but still contains large amounts of forested areas and 

smaller amounts of open, grassland areas; its bacteria 

sources reflect this land-use pattern. The human population in the watershed is estimated to be about 

110,000; therefore, the presence of human-source bacteria is not surprising. It is unknown, however, whether 

this human waste source is contributed by failing septic 

systems, leaking sewer lines, cross-connected sewer 

and storm drains, or straight pipes. Similarly, the dominant contributions from waterfowl are not surprising, 

given the large resident goose and waterfowl populations in the watershed. Waterfowl populations in the 

area are large because of an abundance of golf course 

ponds, development lakes, public parks, and other 

standing water bodies throughout the watershed. The 

proximity of waterfowl to the stream (and its tributaries) is also likely an important component of the large 

waterfowl contribution. The significant contributions 

from dogs and cats are indicative of a large pet population. Wildlife was also an important contributor, and 

wildlife populations have adapted to both the urban 

and forested areas of this watershed.

Land use in the Blacks Run watershed reflects the 

urban activities of the city of Harrisonburg and the 

agricultural activities that dominate the downstream 

portions of the watershed. The human population of the 

watershed is approximately 34,700, providing a source 

of human waste that could enter the stream through 

multiple pathways. Agricultural activities in the watershed are demonstrated by the areas of cropland, hayland, and pastureland; however, the agricultural 

activities also include intensive cattle and poultry farming (County of Rockingham, Department of Planning 

and Zoning, 1997). The intensive cattle and poultry 

farming are likely the source of the cattle and poultry 

contributions in Blacks Run; however, the mechanisms 

by which these bacteria are transported into the stream 

are uncertain. Erosion of field-applied manure is one

Figure 14. Bacteria sources identified in streamwater samples collected 

March 1999 through October 2000 from three watersheds in Virginia, 

grouped by animal category.

0

10

20

30

40

50

60

HUMAN PET WATERFOWL WILDLIFE AGRICULTURAL

Accotink Creek

Blacks Run

Christians Creek

PERCENT CONTRIBUTION

IDENTIFIED BACTERIA SOURCE

Figure 15. Land use in the Accotink Creek, Blacks Run, and Christians 

Creek watersheds, Virginia. Urban represents residential and commercial 

uses; grassland in the Accotink Creek watershed is primarily parks, golf 

courses, and residential lawns; grassland in the Blacks Run and Christians 

Creek watersheds is primarily pastureland. See figures 2-4 for sources of 

land-use data.

0

10

20

30

40

50

60

70

URBAN FOREST GRASSLAND HAYLAND CROPLAND

PERCENT DISTRIBUTION

Accotink Creek

Blacks Run

Christians Creek

LAND USE
Patterns and Sources of Fecal Coliform Bacteria 33

potential mechanism. Direct deposition of waste into 

the stream by cattle (in areas where cattle have direct 

access to the stream) also may be important. Human 

activities in both the urban and agricultural areas are 

likely responsible for the pet contributions of bacteria 

to the stream.

The Christians Creek watershed is dominated by 

agricultural activities and forested areas; urban areas 

are minimal. The human population of the watershed is 

approximately 12,000—considerably smaller than 

either of the other two watersheds. Although fewer 

people live in the Christians Creek watershed, E. coli of 

human origin were detected and were an important 

contributor to the stream. Christians Creek may have a 

higher occurrence of near-stream contributors than the 

other study streams. Three straight pipes have been 

identified in the watershed; these pipes may route 

untreated wastewater from three houses directly into 

the stream. These three straight pipes may or may not 

be contributing an appreciable quantity of the human E. 

coli that are observed at the ambient water-quality sampling station; however, they demonstrate the potential 

for other straight pipes and a condition in which a single, near-stream source (a straight pipe, for example) 

may contribute more bacteria than another mechanism 

(numerous failing septic systems that are located a considerable distance away from the stream, for example). 

Human activities in the watershed are likely responsible for the pet contributions of E. coli to the stream. 

Agricultural practices are dominant in this watershed; 

however, the density of these agricultural activities is 

lower than in the Blacks Run watershed. Similar to 

Blacks Run, cattle and poultry production accounts for 

the primary livestock populations in the watershed; 

these livestock generate large amounts of feces that 

may be routed into the stream. Numerous horse farms 

are also located in this watershed, providing a source 

for the horse waste in the stream. The mixture of forested and agricultural land produces a habitat that is 

conducive to populations of white-tailed deer and other 

wildlife.

As an emerging technology, published BST studies 

are limited; however, other studies have presented field 

results that can be compared to the results from this 

study. Four Mile Run (a nearby watershed, approximately 5 miles east of Accotink Creek) was studied by 

Simmons and others (2000). The Four Mile Run watershed has similar land-use practices and watershed characteristics as Accotink Creek. Simmons and others 

(2000) used a different method of BST (pulsed-field 

gel electrophoresis) and a different sampling protocol 

than used here; however, their identified bacterial 

sources were similar to those observed in Accotink 

Creek (fig. 16). Waterfowl, human sources, and dogs 

all were identified as major contributors of bacteria to 

both systems. Even though less similar contributions 

were observed for raccoons, deer, and cats, both studies 

identified these animals as contributors. Studies in 

analogous watersheds are not available for direct comparison with the study results in Christians Creek (the 

agricultural watershed) and Blacks Run (the mixed 

urban and agricultural watershed); however, others 

have performed source-tracking (using antibiotic resistance analysis) studies in agricultural watersheds. Cattle have been identified as the primary contributor of 

fecal coliform bacteria in some agricultural watersheds 

in Virginia (Hagedorn and others, 1999; Wiggins, 

1996). Although the contributions were less than those 

observed in Christians Creek and Blacks Run, Wiggins 

(1996) also documented bacteria contributions from 

both poultry and human sources in some agricultural 

watersheds.

Despite the wide-spread occurrence of elevated 

fecal coliform concentrations in surface waters, this 

water-quality condition appears to be reversible. In two 

watersheds (one dominated by wildlife sources, the 

other dominated by agricultural sources), previous 

studies demonstrated that reducing the dominant 

sources of fecal pollution identified by BST methods 

may result in significantly improved water quality 

(Hagedorn and others, 1999; Simmons and others, 

1995). Hagedorn and others (1999) observed an average fecal coliform concentration reduction of 94 percent following the implementation of source-control 

measures.

Temporal variability in the bacteria sources

The effects of flow on the distribution of bacteria 

sources were evaluated by comparing the distribution 

of bacteria sources during low-flow periods and 

storm-flow periods (fig. 17). It was expected that the 

bacteria sources would differ between these low-flow 

and high-flow periods as runoff processes occurred and 

waste from different sources was flushed into the 

streams. Although there were small variations in the 

source contributions, the data indicated that distributions of bacteria sources were relatively uniform during 

both sampling periods; major contributors during 

low-flow periods were major contributors during 
34 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

Figure 16. Distribution of identified bacteria sources in two neighboring watersheds, 

Accotink Creek and Four Mile Run, Virginia. (Four Mile Run data from Don Waye, 

Northern Virginia Regional Commission, written commun, 2001.)

Accotink Creek

Waterfowl

40%

Human 

21%

Dog 

13%

Cat 

7%

Raccoon 

5%

Deer 

1%

Other 

13%

Four Mile Run

Waterfowl 

31%

Human 

18% Dog 

13%

Cat 

1%

Raccoon 

19%

Deer 

6%

Other

12%
Patterns and Sources of Fecal Coliform Bacteria 35

Figure 17. Top eight bacteria sources from low-flow and storm-flow streamwater samples collected March 

1999 through October 2000 in Accotink Creek (A), Blacks Run (B), and Christians Creek (C), Virginia.

(A)

(B)

(C)

0

5

10

15

20

25

30

Goose

Human

Dog

Duck

Cat

Sea gull

Raccoon

Rodent

0

5

10

15

20

25

30

Cattle

Poultry

Human

Dog

Cat

Raccoon

Horse

Deer

0

5

10

15

20

25

30

PERCENT CONTRIBUTION PERCENT CONTRIBUTION PERCENT CONTRIBUTION

Low-flow samples

Storm-flow samples

Low-flow samples

Storm-flow samples

Low-flow samples

Storm-flow samples

Poultry

Cattle

Human

Dog

Horse

Deer

Cat

Duck

IDENTIFIED BACTERIA SOURCE
36 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

storm-flow periods, and minor contributors during 

low-flow periods were minor contributors during 

storm-flow periods. Although no statistical analysis 

was performed to establish error bars on these plots 

(fig. 17), the relatively small number of isolates in each 

flow category and data analysis indicate that differences of 5 percent or less would be inconclusive. Using 

this criterion, the Christians Creek data indicated that 

there might be a slight increase in poultry and human 

sources during storm events; however, these increases 

were not indicated in either the Accotink Creek or 

Blacks Run data.

The observation of relatively uniform distributions 

of bacteria sources during both low-flow and high-flow 

periods remains largely unexplained. This pattern may 

indicate that the bed-sediment reservoir of these 

streams is a significant source of fecal coliform contamination in the water column. In this scenario, a 

“sloughing off” of bacteria from the bed-sediment surface may produce the low-flow distributions of fecal 

coliforms. During storm-flow periods, these same bed 

sediments are re-suspended into the water column. If 

no other factors were affecting the streamwater fecal 

coliform bacteria composition, this situation would 

result in similar distributions of low-flow and 

storm-flow bacteria sources. Because streamflow generation, suspended-sediment transport, and fecal 

coliform transport are complex processes, however, this 

scenario is probably oversimplified. Alternatively, the 

complex runoff processes that are initiated during 

storm events may combine to produce a similar 

bacteria source distribution to that observed in these 

three streams during low-flow periods. To our knowledge, no other studies have reported the effects of flow 

on bacteria-source distributions. The potential for a 

variation in the distributions of fecal coliform bacteria 

sources between low-flow and storm-flow periods 

requires further investigation.

Seasonal patterns in the bacteria-source distributions also were investigated (fig. 18). To have enough 

isolates in each seasonal category for a meaningful 

analysis, the seasonal evaluation only involved a comparison of the relatively warm months (April-September) with the relatively cool months (October-March). 

Only the low-flow samples were used for this analysis 

to ensure that slight differences between low-flow and 

storm-flow distributions were not misinterpreted as 

seasonal patterns. Although some variability was evident in the data, the Accotink Creek results failed to 

demonstrate seasonality. Seasonal patterns were not 

necessarily expected in Accotink Creek because the 

populations of fecal coliform sources in the watershed 

remain stable over the entire year. The Blacks Run data 

indicated seasonality in the poultry contributions, with 

higher percent contributions during the cool months 

and lower percent contributions during the warm 

months. This seasonal pattern is logical because the 

early spring and the late fall (the cool months) are generally when poultry litter is applied to the agricultural 

fields for fertilizer and as a method of waste disposal. If 

this field-applied manure were being washed off the 

fields and into Blacks Run, a larger poultry contribution would be expected during and immediately after 

application to fields. A similar seasonal pattern was 

also observed in Christians Creek; in addition to the 

increased importance of poultry contributions during 

cool months, however, there also appeared to be an 

increase in the percentage of cattle contributions during 

warm months. This seasonal pattern is consistent with 

the animal-management practices in the Christians 

Creek watershed. Similar to the Blacks Run watershed, 

poultry litter applications generally occur in the late 

fall and early spring. Many cattle herds had direct 

access to Christians Creek, and during the warmer 

months, cattle were observed wading into streams and 

spending many hours wallowing (and sometimes defecating) in the stream. During the cooler months, cattle 

still visited the streams as a water source, but their time 

spent in direct contact with the water was reduced 

greatly compared to the warmer months. This pattern 

of animal behavior would produce the observed relative 

dominance by cattle sources during the warm months 

and a shift to dominance by poultry sources during the 

cool months. A review of the Blacks Run data indicated 

a 7-percent increase in the cattle contributions during 

the warm months. Although this increase in the Blacks 

Run cattle contribution may not be significant, it lends 

additional support to the observed seasonal pattern. A 

similar increase in the contributions of cattle sources 

during the hot summer months was also observed by 

Bower (2001). Although the observed seasonal patterns 

in this study are consistent with the land-use and agricultural practices in each watershed, additional sampling and more detailed discretization (consideration of 

four seasons) would be needed to confirm these seasonal patterns and further explore the more subtle 

changes that might be occurring in the contributions 

from the less dominant fecal coliform sources.
Patterns and Sources of Fecal Coliform Bacteria 37

Figure 18. Top eight bacteria sources from low-flow streamwater samples collected April through 

September 1999 and October 1999 through March 2000 from Accotink Creek (A), Blacks Run (B), and 

Christians Creek (C), Virginia.

(A)

(B)

(C)

0

5

10

15

20

25

30

35

40

Duck

Human

Dog

Raccoon

Cat

Sea gull

Rodent

Goose

Warm months (April-September)

Cool months (October-March)

Warm months (April-September)

Cool months (October-March)

Warm months (April-September)

Cool months (October-March)

0

5

10

15

20

25

30

35

40

Cattle

Human

Dog

Deer

Cat

Raccoon

Poultry

Goose

0

5

10

15

20

25

30

35

40

Cattle

Human

Dog

Deer

Cat

Horse

Poultry

Goose

PERCENT CONTRIBUTION PERCENT CONTRIBUTION PERCENT CONTRIBUTION

IDENTIFIED BACTERIA SOURCE
38 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

Quality control for the ribotyping results

Quality control for the ribotyping method was done 

through a blind isolate experiment. In this experiment, 

23 known E. coli source isolates were randomly 

selected from the source library at the UWMSTL and 

sent to the USGS Virginia District for preparation and 

blinding. The 23 original source isolates were prepared 

as single, duplicate, or triplicate blind isolates and 

re-labeled with a key that was known only to USGS 

personnel (the number of blind isolates prepared from 

each original source isolate also was not revealed to the 

UWMSTL). A total of 66 blind isolates was then 

returned to the UWMSTL for ribotyping analysis. The 

UWMSTL used the ribotype patterns to identify which 

blind isolates were replicates (E. coli from the same 

original source isolate) and to match the blind isolate 

with the original source isolate from the known-source 

library (table 6). The UWMSTL successfully identified 

all replicate isolates and associated the blind isolates 

with the original 23 isolates from the known-source 

library. This quality-control experiment supports the 

capacity of the ribotyping method to generate reproducible, isolate-specific banding patterns, and supports 

the utility of ribotyping for fingerprinting E. coli. 

The observations of poultry waste in Christians 

Creek and Blacks Run were supported by Hancock and 

others (2000), who examined arsenic concentrations in 

Christians Creek streamwater during both low-flow 

and storm-flow periods. The bedrock and soils of the 

Christians Creek watershed are not considered an 

arsenic source; however, feed amendments containing 

arsenic (such as Roxarsone, 3-nitro-4-hydroxyphenylarsonic acid) are commonly used in the poultry industry. The arsenic generally passes through the birds 

(Aschbacher and Feil, 1991) and is excreted with their 

feces (Morrison, 1969; Kunkle and others, 1981). Field 

application of poultry litter (which may contain this 

excreted arsenic) and transport during subsequent 

storm events may flush poultry-derived arsenic into the 

streams. Hancock and others (2000) found that detectable concentrations of total arsenic were present during 

low-flow conditions and that the total arsenic concentration increased during a storm event, supporting the 

hypothesis that field-applied poultry waste was flushed 

into streams. The poultry litter that was flushed into 

streams was also a likely source of the poultry contributions observed here.

In these streams, the presence of fecal coliform bacteria from humans was not unexpected; however, the 

identification of humans as one of the top three contributors in each stream was unexpected. The presence of 

human waste in these streams also was indicated by the 

presence of caffeine and cotinine, both of which can be 

used as chemical tracers of human wastewater (S.D. 

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

2002). Caffeine is a stimulant that is commonly found 

in many beverages (like coffee and soda) whereas cotinine is a metabolite of nicotine (the primary source 

being cigarettes). Some caffeine passes unchanged 

through the human body, whereas cotinine is produced 

as a metabolite; both compounds can then be excreted 

in human waste. Identification of these two compounds 

in streamwater is an indication of the presence of 

human waste, but does not indicate the mechanism by 

which the waste is entering the stream. During a single 

sampling of all three streams, detectable concentrations 

of both caffeine and cotinine were measured at the 

ambient water-quality sampling station of each watershed (fig. 19). Cotinine concentrations are estimated 

because of the method reporting limit. These data cannot be used to quantify the amount of human waste in 

UWMSTL library

identification 

number

USGS replicate identification number

24221 72 – –

24269 70 2 –

25145 67 5 69

26102 64 8 66

26623 61 11 63

26830 58 14 60

13043 52 20 54

13083 49 23 51

13949 46 26 48

14229 43 29 45

14653 40 32 42

15894 37 35 39

16113 34 38 36

18762 28 44 30

18964 25 47 27

19446 22 50 24

19585 19 53 21

19966 16 56 18

22178 7 65 9

24183 1 71 3

17042 73 80 79

21075 84 81 86

24049 87 85 75

Table 6. Design of the quality-control experiment for the ribotyping 

analysis used in this study

[UWMSTL, University of Washington Microbial Source Tracking 

Laboratory; USGS, U.S. Geological Survey; –, no replicate]
Patterns and Sources of Fecal Coliform Bacteria 39

the streams, but they do provide additional, independent evidence of the presence of human waste in all 

three of these streams.

Source-library development and application

Successful application of E. coli-based BST methods requires the development of an extensive 

known-source library that represents all major contributors of feces to a particular watershed. The 

UWMSTL’s ribotyping method involved direct comparison of known-source with unknown-source isolate 

banding patterns, with an exact match in the banding 

patterns required for positive source identification. Isolates that differed by even a single band were not considered matches. Because of these stringent matching 

requirements, this method cannot identify any isolates/ribotypes that are not already a part of the 

known-source database. Two known-source libraries 

were used in the study. These two libraries consisted of 

the UWMSTL’s large database (containing approximately 50,000 isolates) and the UWMSTL’s 

Virginia-specific database (containing approximately 

450 isolates). The Virginia-specific library consisted of 

source isolates that were collected during previous 

investigations unrelated to this study.

To enhance the rate of positive source identification, 723 known-source samples were also collected 

from the three watersheds investigated in this study 

(table 7). Of these 723 samples, only 559 unique banding patterns were obtained (some of the isolates exhibited the same ribotype). These 559 unique isolates were 

then compared to the UWMSTL’s large database and 

the Virginia-specific database. More than half 

(62.8 percent) of the site-specific source isolates that 

were collected during this study were already present 

in the UWMSTL’s large database. Although the 

Virginia-specific database was relatively small (compared to the UWMSTL database), nearly 13 percent of 

the site-specific source isolates that were collected 

were already present in this database. Of the new 

known-source isolates collected, 4.3 percent were classified as transient strains of E. coli (strains that have 

been observed in more than one animal classification). 

Source samples from this study were compared with 

those already in the UWMSTL’s large database and the 

Virginia-specific database; 27.5 percent of the isolates 

were identified as new ribotypes, added to the 

Virginia-specific source library, and used to identify the 

unknown isolates from this study. The large percentage 

of source isolates already present in the UWMSTL’s 

large source database (62.8 percent) supports the conclusion that this database had national relevance and, 

therefore, a national database approach was reasonable 

for this ribotyping method. In addition, although many 

of the known-source isolates in this study were already 

included in the existing source libraries, the contribution of 154 new known-source isolates to the 

Virginia-specific source library was important and supports the need to collect site-specific fecal samples.

An examination of the databases used to identify 

the unknown isolates provided further support for using 

both a database of national scope and a site-specific 

database. For most cases, a record is available of which 

database was used to identify each unknown isolate 

(table 8). Most of the unknown isolates (60.5 percent) 

were identified using the UWMSTL’s large database; 

however, an appreciable percentage of the unknowns 

(12.9 percent) were identified using only the 

Virginia-specific database (this database did include 

the 154 new known-source isolates that were collected 

as part of this study). A portion of the unknown isolates 

(16.1 percent) could be identified using either database, 

and in some cases (10.5 percent), the database used for 

the identification was inadvertently not recorded. These 

results highlight the utility of a large database for the 

ribotyping method; however, the results also demonstrate the need to supplement a large existing database 

with locally collected known-source isolates. If only 

one of these known-source databases had been used for 

identifying the unknown isolates, the number of identified isolates would have decreased considerably (from 

65 percent to 29 percent if only the Virginia-specific

Figure 19. Caffeine and estimated cotinine concentrations measured in 

Accotink Creek on August 8, 2000, Blacks Run on August 15, 2000, and 

Christians Creek on August 1, 2000.

0

0.05

0.1

0.15

0.2

0.25

ACCOTINK 

CREEK

BLACKS RUN CHRISTIANS

CREEK

Caffeine

Cotinine

CONCENTRATION, IN MICROGRAM PER LITER

WATERSHED
40 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

Source

Number of 

source

samples

collected

Unique source 

isolates

identified

Isolates already 

in the 

Virginia-specific 

database

Isolates already 

in the UWMSTL 

large available 

database

Isolates already in 

both databases

Isolates 

identified as 

transient

New source

isolates added

to the Virginia

database

Human 220 168 4 103 15 7 39

Pets

Dog 66 51 3 31 2 4 11

Cat 30 22 1 12 2 1 6

Livestock

Cow 132 83 7 51 4 4 17

Turkey 39 39 3 22 2 0 12

Chicken 28 23 1 15 1 1 5

Horse 16 12 0 5 2 0 5

Sheep 5 5 0 2 0 2 1

Goat 3 3 0 0 0 1 2

Donkey 1 1 0 0 0 0 1

Mule 1 1 0 1 0 0 0

Pig 1 1 0 0 0 0 1

Poultry 1 1 0 0 0 0 1

Wildlife

Goose 47 32 2 17 2 1 10

Duck 28 17 1 9 3 1 3

Deer 21 18 1 8 2 0 7

Muskrat 10 10 2 4 0 1 3

Groundhog 9 9 2 2 1 0 4

Rabbit 9 9 0 3 0 1 5

Squirrel 9 8 0 3 2 0 3

Fox 8 8 1 3 1 0 3

Opossum 7 6 0 3 1 0 2

Raccoon 5 5 2 1 1 0 1

Skunk 5 5 0 2 1 0 2

Hawk 4 4 0 3 0 0 1

Bird 3 3 0 2 0 0 1

Crow 3 3 0 2 0 0 1

Rat 3 3 0 1 0 0 2

Beaver 2 2 0 0 0 0 2

Pigeon 2 2 0 1 0 0 1

Osprey 1 1 0 1 0 0 0

Quail 1 1 0 0 0 0 1

Robin 1 1 0 0 0 0 1

Starling 1 1 0 1 0 0 0

Waterfowl 1 1 0 1 0 0 0

Totals 723 559 30 309 42 24 154

Percentagesa 100 5.4 55.3 7.5 4.3 27.5

Table 7. Summary of source samples collected in the Accotink Creek, Blacks Run, and Christians Creek watersheds, Virginia, from March 1999 

through October 2000, and comparison of the isolates from these source samples with the available source-library databases

[Unique source isolates identified represents the number of genetically distinct source isolates that were observed; this value is generally smaller 

than the number of source samples collected because clones were occasionally observed between source samples. The sum of the 5 columns to 

the right of the unique source isolates identified column is equal to this unique source isolates identified column; UWMSTL, University of 

Washington Microbial Source Tracking Laboratory]

a Percentages are based on the number of unique source isolates identified.
Future Directions 41

database had been used for the source identification). 

The large size of the UWMSTL database is likely the 

reason it was able to identify the majority of the 

unknown isolates; the percentage of isolates identified 

likely would have increased if an even larger 

known-source database had been used. Although the 

size of the UWMSTL large database is important, the 

local nature of the Virginia-specific database is also 

important. In general terms, the fecal sources that have 

been sampled for the Virginia-specific source library 

should be more similar to the actual fecal sources that 

are found in Virginia waterways. Based on this work, 

the best source tracking results are likely produced 

from a coupled approach that utilizes a large available 

source database combined with a location-specific (or 

site-specific) source database.

FUTURE DIRECTIONS

In general, future studies (not just at these three 

impaired watersheds) would be useful in the following 

areas:

• BST studies would benefit from the development 

of standard protocols for sampling and data interpretation, including the total number of isolates to 

source-track in a stream system, the number of isolates to source-track from each water sample, and 

the design and frequency of sampling. In developing these protocols, the different objectives of the 

BST studies must be considered.

• The transport mechanisms by which bacteria can 

be routed into a stream should be identified.

• After the transport mechanisms have been identified and source-management practices have been 

implemented, the capacity of these practices to 

reduce source inputs to streams should be evaluated.

• BST data should provide support and guidance for 

the production of more defendable and scientifically rigorous watershed models. Incorporation of 

these source-tracking data into watershedmanagement strategies should result in the selection of more efficient source-reduction scenarios 

for improving water quality.

• Presently, BST studies are probably too expensive 

to be performed in all impaired stream systems. 

Cost-effective strategies are needed for generating 

bacteria-source information that can be applied to 

the large number of watersheds for which fecal 

coliform watershed models still must be developed.

SUMMARY AND CONCLUSIONS

The U.S. Geological Survey, in cooperation with 

the Virginia Department of Environmental Quality, 

Virginia Department of Conservation and Recreation, 

and Fairfax County, began a 3-year study in 1999 to 

perform bacterial source tracking (BST) on three 

streams in Virginia. The three streams selected for this 

study were Accotink Creek, Christians Creek, and 

Blacks Run, because they represented a range of different land-use practices (urban, agricultural, and mixed 

urban/agricultural, respectively) and potential fecal 

coliform sources. The Virginia Department of Environmental Quality classified these three streams as 

impaired by fecal coliform bacteria because of violations of the of the State’s water-quality standard

(1,000 col/100mL). This study was performed to demonstrate the field application of BST technology and to 

identify the sources of fecal coliform bacteria in these 

three impaired streams. The three streams were sampled over a period of 20 months (March 1999–October 

2000) and over a wide range of hydrological conditions. The ribotyping technique was used to identify the 

sources of the fecal coliform bacteria.

Watershed

Total

number of

isolates

UWMSTL

large database

(percent)

Virginia-specific 

database

(percent)

Both

databases

(percent)

Unspecified

database

(percent)

Accotink Creek 279 177 (63.4) 30 (10.8) 43 (15.4) 29 (10.4)

Blacks Run 285 176 (61.8) 43 (15.1) 43 (15.1) 23 (8.1)

Christians Creek 274 154 (56.2) 35 (12.8) 49 (17.9) 36 (13.1)

Total 838 507 (60.5) 108 (12.9) 135 (16.1) 88 (10.5)

Table 8. Summary of databases used to identify the source of each isolate for this study

[UWMSTL, University of Washington Microbial Source Tracking Laboratory]
42 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

This study demonstrated the utility of BST technology and provided an enhanced understanding of the 

fecal coliform concentrations and sources that impaired 

the Accotink Creek, Blacks Run, and Christians Creek 

watersheds in Virginia. The major findings and conclusions of this study are:

• Fecal coliform concentrations were lowest during 

periods of base flow (typically 

200–2,000 col/100mL) and increased by 3–4 

orders of magnitude during storm events (as high 

as 700,000 col/100mL). 

• Multiple linear regression models can be developed 

to predict fecal coliform bacteria concentrations in 

these streams as a function of water-quality 

parameters (turbidity, pH, water temperature, and 

dissolved oxygen concentration). 

• The major contributors of fecal coliform bacteria in 

each watershed, in order of importance, were:

Accotink Creek: geese, humans, dogs, 

ducks, cats, seagulls, and raccoons.

Blacks Run: cattle, poultry, humans, dogs, 

and cats.

Christians Creek: poultry, cattle, humans, 

dogs, horses, and deer.

• Identified bacteria sources were related to the 

land-use practices within each watershed. 

• For Christians Creek and Blacks Run, seasonal patterns were present in the contributions of E. coli

from cattle and poultry sources. Cattle sources 

were more prevalent during the warm months 

(April–September), whereas poultry sources were 

more prevalent during the cool months (October– 

March).

• There were only minor differences in the distribution of bacteria sources between low-flow periods 

and storm-flow periods. 

• A coupled approach that utilized both a large available source library and a smaller, location-specific 

source library provided the most success in 

identifying unknown E. coli isolates.

• Future studies would benefit from the development 

of more cost-effective, standardized protocols for 

BST techniques, sampling strategies, and data 

analyses.
References Cited 43

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Appendix 45

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Accotink Creek

04/13/99 1000 WAC06 23470 Feline E, V

04/13/99 1000 WAC06 23471 Goose V

04/13/99 1005 WAC07 23473 Opossum n.r.

04/13/99 1005 WAC07 23472 – n.a.

04/13/99 1010 WAC08 23474 Avian E

04/13/99 1010 WAC08 23475 Avian E

04/13/99 1015 WAC09 23477 Dog E

04/13/99 1015 WAC09 23476 – n.a.

04/13/99 1020 WAC10 23478 Dog E

04/13/99 1020 WAC10 23479 Dog E

04/13/99 1025 WAC11 23480 – n.a.

04/13/99 1025 WAC11 23481 – n.a.

04/13/99 1030 WAC12 23482 – n.a.

04/13/99 1030 WAC12 23483 – n.a.

04/13/99 1035 WAC13 23485 Dog E

04/13/99 1035 WAC13 23484 – n.a.

05/24/99 1115 WAC15 23787 Raccoon E

05/24/99 1115 WAC15 23788 Raccoon E

05/24/99 1130 WAC16 23790 Human E

05/24/99 1130 WAC16 23789 – n.a.

05/24/99 1145 WAC17 23792 Human E

05/24/99 1145 WAC17 23791 Human E

05/24/99 1200 WAC18 23794 Human E

05/24/99 1200 WAC18 23793 – n.a.

05/24/99 1230 WAC19 23796 Feline E

05/24/99 1230 WAC19 23795 Raccoon E

05/24/99 1300 WAC20 23798 Duck E

05/24/99 1300 WAC20 23797 – n.a.

05/24/99 1330 WAC21 23799 Dog E

05/24/99 1530 WAC22 23800 Dog E

05/24/99 1530 WAC22 23801 – n.a.

05/24/99 1730 WAC23 23802 Goose V

05/24/99 1730 WAC23 23803 Goose V

05/24/99 1900 WAC24 23805 Duck E

05/24/99 1900 WAC24 23804 Transient n.r.

05/27/99 1115 WAC25 23869 Dog E

05/27/99 1120 WAC26 23870 Dog E

05/27/99 1125 WAC27 23872 Canine n.r.

05/27/99 1125 WAC27 23871 Fox E

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
46 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

05/27/99 1130 WAC28 23874 Goose E

05/27/99 1130 WAC28 23873 – n.a.

05/27/99 1135 WAC29 23876 Dog E

05/27/99 1135 WAC29 23875 – n.a.

05/27/99 1140 WAC30 23878 Human E, V

05/27/99 1140 WAC30 23877 Sea Gull E

05/27/99 1145 WAC31 23879 Human E, V

05/27/99 1150 WAC32 23880 – n.a.

05/27/99 1150 WAC32 23881 – n.a.

07/07/99 1100 WAC33 24353 Dog E

07/07/99 1100 WAC33 24354 Human E

07/07/99 1105 WAC34 24356 Duck E

07/07/99 1105 WAC34 24355 – n.a.

07/07/99 1110 WAC35 24358 Feline E

07/07/99 1110 WAC35 24357 – n.a.

07/07/99 1115 WAC36 24359 Avian E

07/07/99 1115 WAC36 24360 Human E

07/07/99 1120 WAC37 24361 Avian E

07/07/99 1120 WAC37 24362 Dog E

07/07/99 1125 WAC38 24363 Avian E

07/07/99 1125 WAC38 24364 Avian E

07/07/99 1125 WAC38 24365 Feline E

07/07/99 1130 WAC39 24368 Goose V

07/07/99 1130 WAC39 24367 Human E, V

07/07/99 1135 WAC40 24366 Human E, V

07/07/99 1135 WAC40 24369 – n.a.

07/07/99 1135 WAC40 24370 – n.a.

08/14/99 1640 WAC47 24830 Goose E

08/14/99 1640 WAC47 24828 Rodent E

08/14/99 1640 WAC47 24829 – n.a.

08/14/99 1745 WAC48 24831 Avian E

08/14/99 1745 WAC48 24832 Avian E

08/14/99 1745 WAC48 24833 Goose E, V

08/14/99 1915 WAC49 24834 Duck E

08/14/99 1915 WAC49 24835 Human E

08/14/99 1945 WAC50 24836 Duck E

08/14/99 2000 WAC51 24838 Dog E

08/14/99 2000 WAC51 24837 Human E

08/14/99 2000 WAC51 24839 Raccoon E

08/14/99 2010 WAC52 24842 Dog E

08/14/99 2010 WAC52 24840 Dog E, V

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
Appendix 47

08/14/99 2010 WAC52 24841 Goose E, V

08/14/99 2025 WAC53 24845 Bovine E

08/14/99 2025 WAC53 24844 Duck E

08/14/99 2025 WAC53 24843 Feline E, V

08/14/99 2100 WAC54 24847 Feline E, V

08/14/99 2100 WAC54 24848 Goose E

08/14/99 2100 WAC54 24846 – n.a.

08/14/99 2145 WAC55 24849 Avian n.r.

08/14/99 2145 WAC55 24850 Rodent E

08/14/99 2145 WAC55 24851 Rodent E

08/15/99 15 WAC56 24852 Goose V

08/15/99 15 WAC56 24853 – n.a.

08/15/99 15 WAC56 24854 – n.a.

08/17/99 1005 WAC59 24855 Goose E, V

08/17/99 1010 WAC60 24856 – n.a.

08/17/99 1010 WAC60 24857 – n.a.

08/17/99 1010 WAC60 24858 – n.a.

08/17/99 1020 WAC62 24859 Duck E, V

08/17/99 1020 WAC62 24860 – n.a.

08/17/99 1030 WAC64 24861 Goose E, V

08/17/99 1030 WAC64 24862 Human E

09/10/99 2055 WAC65 25306 Avian E

09/10/99 2055 WAC65 25305 Dog E

09/10/99 2137 WAC66 25308 Dog n.r.

09/10/99 2137 WAC66 25307 Human V

09/10/99 2330 WAC67 25310 Rodent E

09/10/99 2330 WAC67 25311 Rodent E

09/10/99 2330 WAC67 25309 – n.a.

09/10/99 2330 WAC67 25312 – n.a.

09/10/99 15 WAC68 25315 Digested Sludge E

09/10/99 15 WAC68 25314 Feline E, V

09/10/99 15 WAC68 25313 Human E

09/10/99 15 WAC68 25316 – n.a.

09/10/99 100 WAC69 25319 Goose E

09/10/99 100 WAC69 25320 Goose E

09/10/99 100 WAC69 25317 Sludge n.r.

09/10/99 100 WAC69 25318 – n.a.

09/10/99 124 WAC71 25321 Dog E

09/10/99 124 WAC71 25323 Dog E

09/10/99 124 WAC71 25324 Duck E

09/10/99 124 WAC71 25322 Human E, V

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
48 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

09/10/99 124 WAC71 25325 Human E

09/10/99 154 WAC72 25326 Goose E, V

09/10/99 154 WAC72 25327 Human E

09/10/99 154 WAC72 25328 Human E

09/10/99 320 WAC73 25330 Feline V

09/10/99 320 WAC73 25331 Feline V

09/10/99 320 WAC73 25329 – n.a.

09/10/99 320 WAC73 25332 – n.a.

09/10/99 603 WAC74 25333 Goose E

09/15/99 640 WAC75 25707 Human E

09/15/99 640 WAC75 25704 Goose E

09/15/99 640 WAC75 25706 Human E

09/15/99 640 WAC75 25705 – n.a.

09/15/99 900 WAC76 25710 Dog E

09/15/99 900 WAC76 25708 Duck E, V

09/15/99 900 WAC76 25709 – n.a.

09/15/99 945 WAC77 25713 Sea Gull E

09/15/99 945 WAC77 25711 – n.a.

09/15/99 945 WAC77 25712 – n.a.

09/15/99 945 WAC77 25714 – n.a.

09/15/99 1115 WAC78 25715 Bovine E

09/15/99 1115 WAC78 25717 Goose E, V

09/15/99 1115 WAC78 25718 Goose E, V

09/15/99 1115 WAC78 25716 – n.a.

09/15/99 1230 WAC79 25722 Dog E

09/15/99 1230 WAC79 25721 Human E, V

09/15/99 1230 WAC79 25719 Muskrat V

09/15/99 1230 WAC79 25720 Muskrat V

09/15/99 1315 WAC80 25725 Dog E

09/15/99 1315 WAC80 25723 – n.a.

09/15/99 1315 WAC80 25724 – n.a.

09/15/99 1315 WAC80 25726 – n.a.

09/15/99 1430 WAC81 25729 Septage n.r.

09/15/99 1430 WAC81 25727 – n.a.

09/15/99 1430 WAC81 25728 – n.a.

09/15/99 1545 WAC82 25733 Goose E

09/15/99 1545 WAC82 25732 Human E

09/15/99 1545 WAC82 25731 Human E, V

09/15/99 1545 WAC82 25730 Sea Gull E

09/15/99 1730 WAC83 25734 – n.a.

09/15/99 2100 WAC84 25735 Coyote E

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
Appendix 49

09/15/99 2100 WAC84 25736 – n.a.

09/16/99 900 WAC85 25738 combined sewer overflow E

09/16/99 900 WAC85 25737 Raccoon E

09/16/99 900 WAC85 25739 – n.a.

09/27/99 1105 WAC86 25847 Rodent E

09/27/99 1105 WAC86 25849 Sea Gull E

09/27/99 1105 WAC86 25848 – n.a.

09/27/99 1110 WAC87 25851 Raccoon E

09/27/99 1110 WAC87 25850 – n.a.

09/27/99 1110 WAC87 25852 – n.a.

09/27/99 1110 WAC87 25853 – n.a.

09/27/99 1115 WAC88 25855 Avian E

09/27/99 1115 WAC88 25854 Dog E, V

09/27/99 1115 WAC88 25856 – n.a.

09/27/99 1115 WAC88 25857 – n.a.

09/27/99 1120 WAC89 25858 Bovine E, V

09/27/99 1120 WAC89 25861 Goose E

09/27/99 1120 WAC89 25859 Goose E, V

09/27/99 1120 WAC89 25860 – n.a.

09/27/99 1125 WAC90 25863 Dog E

09/27/99 1125 WAC90 25865 Dog E

09/27/99 1125 WAC90 25862 – n.a.

09/27/99 1125 WAC90 25864 – n.a.

09/27/99 1130 WAC91 25868 Avian E

09/27/99 1130 WAC91 25869 Avian E

09/27/99 1130 WAC91 25867 Duck E

09/27/99 1130 WAC91 25866 Septage n.r.

09/27/99 1135 WAC92 25870 Avian E

09/27/99 1135 WAC92 25871 Avian E

09/27/99 1135 WAC92 25873 Dog n.r.

09/27/99 1135 WAC92 25872 – n.a.

09/27/99 1140 WAC93 25876 Avian E

09/27/99 1140 WAC93 25877 Raccoon E, V

09/27/99 1140 WAC93 25874 – n.a.

09/27/99 1140 WAC93 25875 – n.a.

09/27/99 1140 WAC93B 25880 Avian E

09/27/99 1140 WAC93B 25878 – n.a.

09/27/99 1140 WAC93B 25879 – n.a.

09/27/99 1140 WAC93B 25881 – n.a.

09/27/99 1140 WAC93C 25882 Dog E

09/27/99 1140 WAC93C 25883 Raccoon E, V

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
50 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

09/27/99 1140 WAC93C 25884 – n.a.

09/27/99 1140 WAC93C 25885 – n.a.

11/10/99 940 WAC94 26511 – n.a.

11/10/99 940 WAC94 26512 Human E

11/10/99 940 WAC94 26513 Septage n.r.

11/10/99 940 WAC94 26514 Bovine E, V

11/10/99 945 WAC95 26515 Human E

11/10/99 945 WAC95 26516 Goose E, V

11/10/99 945 WAC95 26517 Feline E

11/10/99 945 WAC95 26518 – n.a.

11/10/99 950 WAC96 26519 Goose E, V

11/10/99 950 WAC96 26520 Goose E

11/10/99 950 WAC96 26521 Human E

11/10/99 950 WAC96 26522 – n.a.

11/10/99 955 WAC97 26523 Human E

11/10/99 955 WAC97 26524 Duck E

11/10/99 955 WAC97 26525 – n.a.

11/10/99 955 WAC97 26526 Bovine E, V

11/10/99 1000 WAC98 26527 Goose E, V

11/10/99 1000 WAC98 26528 Raccoon E

11/10/99 1000 WAC98 26529 – n.a.

11/10/99 1000 WAC98 26530 Raccoon E

11/10/99 1005 WAC99 26531 Sea Gull n.r.

11/10/99 1005 WAC99 26532 Rabbit E

11/10/99 1005 WAC99 26533 Rabbit E

11/10/99 1005 WAC99 26534 Deer E

11/10/99 1010 WAC100 26535 Deer E

11/10/99 1010 WAC100 26536 Dog V

11/10/99 1010 WAC100 26537 Human E

11/10/99 1010 WAC100 26538 – n.a.

11/10/99 1015 WAC101 26539 – n.a.

11/10/99 1015 WAC101 26540 Human E, V

11/10/99 1015 WAC101 26541 Human E, V

11/10/99 1015 WAC101 26542 Feline E

11/10/99 1015 WAC101B 26543 Goose E

11/10/99 1015 WAC101B 26544 Dog E

11/10/99 1015 WAC101B 26545 – n.a.

11/10/99 1015 WAC101B 26546 – n.a.

11/10/99 1015 WAC101B 26547 Avian E

11/10/99 1015 WAC101C 26548 Avian n.r.

11/10/99 1015 WAC101C 26549 Avian n.r.

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
Appendix 51

11/10/99 1015 WAC101C 26550 Feline E

11/10/99 1015 WAC101C 26551 Dog E

12/21/99 1215 WAC102 26864 Avian E

12/21/99 1215 WAC102 26865 Goose n.r.

12/21/99 1215 WAC102 26866 Goose n.r.

12/21/99 1220 WAC103 26868 Sea Gull E

12/21/99 1220 WAC103 26870 Sea Gull E

12/21/99 1220 WAC103 26867 – n.a.

12/21/99 1220 WAC103 26869 – n.a.

12/21/99 1225 WAC104 26874 Digested Sludge E

12/21/99 1225 WAC104 26873 Goose E

12/21/99 1225 WAC104 26871 – n.a.

12/21/99 1225 WAC104 26872 – n.a.

12/21/99 1230 WAC105 26877 Goose E

12/21/99 1230 WAC105 26878 Goose V

12/21/99 1230 WAC105 26875 Human E

12/21/99 1230 WAC105 26876 Sheep V

12/21/99 1235 WAC106 26881 Goose V

12/21/99 1235 WAC106 26879 – n.a.

12/21/99 1235 WAC106 26880 – n.a.

12/21/99 1235 WAC106 26882 – n.a.

12/21/99 1240 WAC107 26883 Human E

12/21/99 1240 WAC107 26884 Sea Gull E

12/21/99 1240 WAC107 26886 Sea Gull E

12/21/99 1240 WAC107 26885 – n.a.

12/21/99 1245 WAC108 26890 Avian n.r.

12/21/99 1245 WAC108 26887 Canine E

12/21/99 1245 WAC108 26888 Goose V

12/21/99 1245 WAC108 26889 – n.a.

12/21/99 1250 WAC109 26892 Dog E

12/21/99 1250 WAC109 26893 Duck E

12/21/99 1250 WAC109 26891 Human V

12/21/99 1250 WAC109 26894 Human E, V

12/21/99 1250 WAC109B 26896 Feline n.r.

12/21/99 1250 WAC109B 26897 Goose E

12/21/99 1250 WAC109B 26895 – n.a.

12/21/99 1250 WAC109B 26898 – n.a.

12/21/99 1250 WAC109C 26899 Dog n.r.

12/21/99 1250 WAC109C 26900 Goose E, V

03/24/00 1315 WAC111 27877 Human n.r.

03/24/00 1315 WAC111 27875 – n.a.

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
52 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

03/24/00 1315 WAC111 27876 – n.a.

03/24/00 1320 WAC112 27878 Avian E

03/24/00 1320 WAC112 27879 Human n.r.

03/24/00 1320 WAC112 27880 – n.a.

03/24/00 1325 WAC113 27882 Dog E

03/24/00 1325 WAC113 27883 Human V

03/24/00 1325 WAC113 27881 Human n.r.

03/24/00 1330 WAC114 27884 Human V

03/24/00 1330 WAC114 27886 Transient n.r.

03/24/00 1330 WAC114 27885 – n.a.

03/24/00 1330 WAC114B 27887 Avian E

03/24/00 1330 WAC114B 27888 Bear E

03/24/00 1330 WAC114B 27889 – n.a.

03/24/00 1330 WAC114C 27891 Rodent E

03/24/00 1330 WAC114C 27892 Rodent E

03/24/00 1330 WAC114C 27890 – n.a.

05/03/00 1315 WAC115 29752 Avian E

05/03/00 1315 WAC115 29753 Avian E

05/03/00 1315 WAC115 29751 – n.a.

05/03/00 1320 WAC116 29754 Human E

05/03/00 1320 WAC116 29756 Human V

05/03/00 1320 WAC116 29755 Swan V

05/03/00 1325 WAC117 29757 Human V

05/03/00 1325 WAC117 29758 Human E

05/03/00 1325 WAC117 29759 Rodent E

05/03/00 1330 WAC118 29762 Avian E, V

05/03/00 1330 WAC118 29760 Human V

05/03/00 1330 WAC118 29761 – n.a.

05/03/00 1330 WAC118B 29764 Raccoon V

05/03/00 1330 WAC118B 29763 – n.a.

05/03/00 1330 WAC118B 29765 – n.a.

05/03/00 1330 WAC118C 29767 Avian E

05/03/00 1330 WAC118C 29766 – n.a.

05/03/00 1330 WAC118C 29768 – n.a.

05/31/00 1100 WAC119 31168 Avian n.r.

05/31/00 1100 WAC119 31169 Duck E

05/31/00 1100 WAC119 31170 – n.a.

05/31/00 1105 WAC120 31172 Avian E

05/31/00 1105 WAC120 31173 Human V

05/31/00 1105 WAC120 31171 Raccoon E

05/31/00 1110 WAC121 31175 Avian E

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
Appendix 53

05/31/00 1110 WAC121 31174 Human E

05/31/00 1110 WAC121 31176 Raccoon E

05/31/00 1115 WAC122 31179 Goose V

05/31/00 1115 WAC122 31177 – n.a.

05/31/00 1115 WAC122 31178 – n.a.

05/31/00 1115 WAC122B 31181 Bovine E, V

05/31/00 1115 WAC122B 31182 Feline E

05/31/00 1115 WAC122B 31180 – n.a.

05/31/00 1115 WAC122C 31183 Feline E

05/31/00 1115 WAC122C 31184 – n.a.

05/31/00 1115 WAC122C 31185 – n.a.

06/05/00 2000 WAC123 31502 Dog E

06/05/00 2000 WAC123 31501 Sea Gull E

06/06/00 815 WAC124 31504 Duck E

06/06/00 815 WAC124 31505 Duck E

06/06/00 815 WAC124 31503 – n.a.

06/06/00 935 WAC125 31507 Deer E

06/06/00 935 WAC125 31508 Deer E

06/06/00 935 WAC125 31506 – n.a.

06/06/00 1000 WAC126 31509 Goose n.r.

06/06/00 1000 WAC126 31510 Goose n.r.

06/06/00 1000 WAC126 31511 – n.a.

06/06/00 1015 WAC127 31513 Dog E

06/06/00 1015 WAC127 31514 Human E, V

06/06/00 1015 WAC127 31512 – n.a.

06/06/00 1030 WAC128 31516 Ground Hog V

06/06/00 1030 WAC128 31515 Rabbit E

06/06/00 1030 WAC128 31517 – n.a.

06/06/00 1045 WAC129 31519 Bovine E

06/06/00 1045 WAC129 31518 Feline E

06/06/00 1045 WAC129 31520 Human E

06/06/00 1050 WAC130 31521 – n.a.

06/06/00 1050 WAC130 31522 – n.a.

06/06/00 1050 WAC130 31523 – n.a.

06/06/00 1130 WAC131 31526 Human E, V

06/06/00 1130 WAC131 31524 Raccoon E

06/06/00 1130 WAC131 31525 Raccoon E

06/06/00 1310 WAC132 31528 Avian n.r.

06/06/00 1310 WAC132 31529 Avian n.r.

06/06/00 1310 WAC132 31527 – n.a.

06/06/00 2037 WAC133 31531 Avian E

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
54 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

06/06/00 2037 WAC133 31532 Avian E

06/06/00 2037 WAC133 31530 – n.a.

07/11/00 1100 WAC134 33258 Duck E, V

07/11/00 1100 WAC134 33257 Feline E

07/11/00 1100 WAC134 33259 Feline E

07/11/00 1105 WAC135 33260 Feline E

07/11/00 1105 WAC135 33261 Human E

07/11/00 1105 WAC135 33262 Human E

07/11/00 1110 WAC136 33263 Poultry n.r.

07/11/00 1110 WAC136 33264 – n.a.

07/11/00 1110 WAC136 33265 – n.a.

07/11/00 1115 WAC137 33266 Avian n.r.

07/11/00 1115 WAC137 33267 Goose V

07/11/00 1115 WAC137 33268 Goose V

07/11/00 1115 WAC137B 33270 Horse E

07/11/00 1115 WAC137B 33269 Rodent E

07/11/00 1115 WAC137B 33271 – n.a.

07/11/00 1115 WAC137C 33273 Feline E

07/11/00 1115 WAC137C 33272 Human E

07/11/00 1115 WAC137C 33274 Human V

08/10/00 745 WAC143 34687 Goose E, V

08/10/00 745 WAC143 34688 Goose E, V

08/10/00 745 WAC143 34686 – n.a.

08/10/00 750 WAC144 34691 Human V

08/10/00 750 WAC144 34689 – n.a.

08/10/00 750 WAC144 34690 – n.a.

08/10/00 750 WAC145 34692 – n.a.

08/10/00 750 WAC145 34693 – n.a.

08/10/00 750 WAC145 34694 – n.a.

08/10/00 755 WAC146 34695 Human E, V

08/10/00 755 WAC146 34696 – n.a.

08/10/00 755 WAC146 34697 – n.a.

08/10/00 800 WAC147 34699 Avian E

08/10/00 800 WAC147 34700 Avian E

08/10/00 800 WAC147 34698 – n.a.

08/10/00 800 WAC148 34703 Dog E

08/10/00 800 WAC148 34702 – n.a.

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
Appendix 55

Blacks Run

04/27/99 1430 WBR06 23551 Human E

04/27/99 1430 WBR06 23552 Raccoon V

04/27/99 1435 WBR07 23554 Bovine E, V

04/27/99 1435 WBR07 23553 Dog E

04/27/99 1440 WBR08 23556 Human E

04/27/99 1440 WBR08 23555 – n.a.

04/27/99 1445 WBR09 23557 Bovine E

04/27/99 1445 WBR09 23558 – n.a.

04/27/99 1450 WBR10 23559 Bovine E

04/27/99 1450 WBR10 23560 Human E

04/27/99 1455 WBR11 23561 Bovine E

04/27/99 1455 WBR11 23562 – n.a.

04/27/99 1500 WBR12 23564 Dog E, V

04/27/99 1500 WBR12 23563 – n.a.

04/27/99 1505 WBR13 23565 Avian E

04/27/99 1505 WBR13 23566 – n.a.

05/08/99 300 WBR14 23674 Bovine E

05/08/99 300 WBR14 23675 Bovine E

05/08/99 345 WBR15 23676 Bovine E

05/08/99 345 WBR15 23677 Sea Gull E

05/08/99 445 WBR16 23678 Feline E, V

05/08/99 445 WBR16 23679 Sea Gull E

05/08/99 545 WBR17 23681 Bovine V

05/08/99 545 WBR17 23680 Poultry E

05/08/99 745 WBR18 23683 Horse E

05/08/99 745 WBR18 23682 Human E

05/08/99 1015 WBR19 23684 – n.a.

05/08/99 1015 WBR19 23685 – n.a.

05/08/99 1115 WBR20 23686 – n.a.

05/08/99 1115 WBR20 23687 – n.a.

05/08/99 1345 WBR21 23688 Dog E

05/08/99 1345 WBR21 23689 Horse E

05/08/99 1445 WBR22 23690 Bovine E, V

05/08/99 1445 WBR22 23691 – n.a.

05/08/99 1645 WBR23 23692 Bovine E

05/08/99 1645 WBR23 23693 – n.a.

06/09/99 1425 WBR24 24128 Dog E

06/09/99 1425 WBR24 24129 – n.a.

06/09/99 1430 WBR25 24131 Bovine E, V

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
56 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

06/09/99 1430 WBR25 24130 Poultry E

06/09/99 1435 WBR26 24133 Human E

06/09/99 1435 WBR26 24132 – n.a.

06/09/99 1440 WBR27 24135 Bovine E, V

06/09/99 1440 WBR27 24134 Dog E

06/09/99 1445 WBR28 24136 Bovine V

06/09/99 1445 WBR28 24137 Duck V

06/09/99 1450 WBR29 24139 Dog E

06/09/99 1450 WBR29 24138 – n.a.

06/09/99 1455 WBR30 24140 Feline E

06/09/99 1455 WBR30 24141 Poultry E, V

06/09/99 1500 WBR31 24143 Human E

06/09/99 1500 WBR31 24142 Poultry E, V

07/20/99 925 WBR32 24615 Human V

07/20/99 925 WBR32 24616 Human V

07/20/99 930 WBR33 24617 – n.a.

07/20/99 930 WBR33 24618 Bovine n.r.

07/20/99 935 WBR34 24619 Bovine n.r.

07/20/99 935 WBR34 24620 – n.a.

07/20/99 940 WBR35 24621 Bovine E

07/20/99 940 WBR35 24622 Bovine E

07/20/99 945 WBR36 24623 Bovine E

07/20/99 945 WBR36 24624 – n.a.

07/20/99 950 WBR37 24625 Human E

07/20/99 950 WBR37 24626 Bovine E, V

07/20/99 955 WBR38 24627 Avian E

07/20/99 955 WBR38 24628 – n.a.

07/20/99 920 WBR39 24629 Bovine E

07/20/99 920 WBR39 24630 – n.a.

08/25/99 1250 WBR51 24892 – n.a.

08/25/99 1250 WBR51 24893 – n.a.

08/25/99 1250 WBR51 24894 – n.a.

08/25/99 1255 WBR52 24896 Bovine E

08/25/99 1255 WBR52 24898 Bovine E, V

08/25/99 1255 WBR52 24895 Poultry V

08/25/99 1255 WBR52 24897 – n.a.

08/25/99 1300 WBR53 24900 Bovine E

08/25/99 1300 WBR53 24899 – n.a.

08/25/99 1300 WBR53 24901 – n.a.

08/25/99 1305 WBR54 24903 Feline E

08/25/99 1305 WBR54 24902 – n.a.

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
Appendix 57

08/25/99 1305 WBR54 24904 – n.a.

08/25/99 1310 WBR55 24906 Human E

08/25/99 1310 WBR55 24907 Human E

08/25/99 1310 WBR55 24905 – n.a.

08/25/99 1315 WBR56 24909 Human E

08/25/99 1315 WBR56 24908 – n.a.

08/25/99 1315 WBR56 24910 – n.a.

08/25/99 1320 WBR57 24911 Poultry V

08/25/99 1320 WBR57 24912 – n.a.

08/25/99 1320 WBR57 24913 – n.a.

08/25/99 1325 WBR58 24915 Poultry V

08/25/99 1325 WBR58 24914 – n.a.

08/25/99 1325 WBR58 24916 – n.a.

09/15/99 1845 WBR59 25741 Bovine E

09/15/99 1845 WBR59 25740 Poultry E

09/15/99 1845 WBR59 25742 – n.a.

09/15/99 1845 WBR59 25743 – n.a.

09/15/99 2127 WBR60 25744 – n.a.

09/15/99 2127 WBR60 25745 – n.a.

09/15/99 2127 WBR60 25746 – n.a.

09/15/99 2127 WBR60 25747 – n.a.

09/15/99 542 WBR61 25749 Bovine E

09/15/99 542 WBR61 25748 – n.a.

09/15/99 542 WBR61 25750 – n.a.

09/15/99 542 WBR61 25751 – n.a.

09/15/99 610 WBR62 25752 Avian E

09/15/99 610 WBR62 25753 – n.a.

09/15/99 610 WBR62 25754 – n.a.

09/15/99 610 WBR62 25755 – n.a.

09/15/99 745 WBR63 25758 Bovine E

09/15/99 745 WBR63 25756 Poultry n.r.

09/15/99 745 WBR63 25757 – n.a.

09/15/99 745 WBR63 25759 – n.a.

09/15/99 916 WBR64 25762 Bovine E, V

09/15/99 916 WBR64 25760 Horse E

09/15/99 916 WBR64 25761 Human V

09/15/99 916 WBR64 25763 Poultry E, V

09/15/99 1045 WBR65 25767 Human n.r.

09/15/99 1045 WBR65 25765 Opossum n.r.

09/15/99 1045 WBR65 25766 Poultry V

09/15/99 1045 WBR65 25764 – n.a.

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
58 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

09/15/99 1340 WBR66 25770 Bovine E

09/15/99 1340 WBR66 25768 Poultry n.r.

09/15/99 1340 WBR66 25769 Raccoon E

09/15/99 1340 WBR66 25771 – n.a.

09/15/99 1830 WBR67 25773 Avian E

09/15/99 1830 WBR67 25775 Deer E

09/15/99 1830 WBR67 25774 Poultry V

09/15/99 1830 WBR67 25772 Sheep E

09/15/99 730 WBR68 25776 Avian E

09/15/99 730 WBR68 25777 Avian E

09/15/99 730 WBR68 25778 Bovine E

09/15/99 730 WBR68 25779 Poultry V

010/13/99 930 WBR69 26130 Avian n.r.

010/13/99 930 WBR69 26131 Poultry V

010/13/99 930 WBR69 26129 – n.a.

010/13/99 930 WBR69 26132 – n.a.

010/13/99 935 WBR70 26134 Avian E

010/13/99 935 WBR70 26133 – n.a.

010/13/99 935 WBR70 26135 – n.a.

010/13/99 935 WBR70 26136 – n.a.

010/13/99 940 WBR71 26139 Bovine E, V

010/13/99 940 WBR71 26140 Bovine E, V

010/13/99 940 WBR71 26138 Human V

010/13/99 940 WBR71 26137 – n.a.

010/13/99 945 WBR72 26143 Dog E

010/13/99 945 WBR72 26144 Sanitary Sewer E

010/13/99 945 WBR72 26141 – n.a.

010/13/99 945 WBR72 26142 – n.a.

010/13/99 950 WBR73 26147 Avian n.r.

010/13/99 950 WBR73 26145 Cat E

010/13/99 950 WBR73 26148 Raccoon E

010/13/99 950 WBR73 26146 – n.a.

010/13/99 955 WBR74 26151 Bovine E

010/13/99 955 WBR74 26152 Bovine E

010/13/99 955 WBR74 26149 – n.a.

010/13/99 955 WBR74 26150 – n.a.

010/13/99 1000 WBR75 26156 Avian n.r.

010/13/99 1000 WBR75 26155 Turkey E

010/13/99 1000 WBR75 26153 Turkey V

010/13/99 1000 WBR75 26154 – n.a.

010/13/99 1005 WBR76 26160 Bovine E

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
Appendix 59

010/13/99 1005 WBR76 26158 Horse E

010/13/99 1005 WBR76 26157 – n.a.

010/13/99 1005 WBR76 26159 – n.a.

010/13/99 1005 WBR76B 26164 Bovine V

010/13/99 1005 WBR76B 26161 Bovine E

010/13/99 1005 WBR76B 26162 Bovine E

010/13/99 1005 WBR76B 26163 Bovine E

010/13/99 1005 WBR76C 26166 Avian n.r.

010/13/99 1005 WBR76C 26165 Bovine E

010/13/99 1005 WBR76C 26168 Feline E

010/13/99 1005 WBR76C 26167 – n.a.

11/03/99 15 WBR77 26444 Horse E

11/03/99 15 WBR77 26441 Human E

11/03/99 15 WBR77 26442 – n.a.

11/03/99 15 WBR77 26443 – n.a.

11/03/99 630 WBR78 26445 Bovine E

11/03/99 630 WBR78 26447 Bovine V

11/03/99 630 WBR78 26448 Dog E

11/03/99 630 WBR78 26446 – n.a.

11/03/99 1300 WBR79 26451 Coyote E

11/03/99 1300 WBR79 26452 Poultry V

11/03/99 1300 WBR79 26449 – n.a.

11/03/99 1300 WBR79 26450 – n.a.

11/03/99 1515 WBR80 26454 Bovine V

11/03/99 1515 WBR80 26453 – n.a.

11/03/99 1515 WBR80 26455 – n.a.

11/03/99 1515 WBR80 26456 – n.a.

11/03/99 1630 WBR81 26459 Bovine V

11/03/99 1630 WBR81 26458 Bovine E, V

11/03/99 1630 WBR81 26460 Bovine E, V

11/03/99 1630 WBR81 26457 Dog E

11/03/99 1645 WBR82 26463 Human E

11/03/99 1645 WBR82 26464 Human E

11/03/99 1645 WBR82 26461 – n.a.

11/03/99 1645 WBR82 26462 – n.a.

11/03/99 1700 WBR83 26465 Avian E

11/03/99 1700 WBR83 26468 Bovine E, V

11/03/99 1700 WBR83 26466 Poultry V

11/03/99 1700 WBR83 26467 – n.a.

11/03/99 1715 WBR84 26471 Bovine E, V

11/03/99 1715 WBR84 26470 Human E

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
60 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

11/03/99 1715 WBR84 26469 Human V

11/03/99 1715 WBR84 26472 Poultry V

11/03/99 1730 WBR85 26476 Bovine E

11/03/99 1730 WBR85 26474 Dog E, V

11/03/99 1730 WBR85 26475 Turkey E, V

11/03/99 1730 WBR85 26473 – n.a.

11/03/99 1845 WBR86 26479 Human E

11/03/99 1845 WBR86 26480 Turkey E, V

11/03/99 1845 WBR86 26477 – n.a.

11/03/99 1845 WBR86 26478 – n.a.

11/03/99 2230 WBR87 26483 Dog E

11/03/99 2230 WBR87 26481 Poultry E

11/03/99 2230 WBR87 26484 Turkey E, V

11/03/99 2230 WBR87 26482 – n.a.

11/03/99 1100 WBR88 26488 Human V

11/03/99 1100 WBR88 26486 Poultry E

11/03/99 1100 WBR88 26485 Sheep V

11/03/99 1100 WBR88 26487 – n.a.

11/22/99 1050 WBR89 26713 Bovine V

11/22/99 1050 WBR89 26712 – n.a.

11/22/99 1050 WBR89 26714 – n.a.

11/22/99 1050 WBR89 26715 – n.a.

11/22/99 1055 WBR90 26717 Bovine V

11/22/99 1055 WBR90 26718 Bovine E, V

11/22/99 1055 WBR90 26716 Feline E

11/22/99 1055 WBR90 26719 Poultry V

11/22/99 1100 WBR91 26720 Bovine V

11/22/99 1100 WBR91 26722 Poultry V

11/22/99 1100 WBR91 26723 Poultry V

11/22/99 1100 WBR91 26721 – n.a.

11/22/99 1105 WBR92 26724 – n.a.

11/22/99 1105 WBR92 26725 – n.a.

11/22/99 1105 WBR92 26726 – n.a.

11/22/99 1105 WBR92 26727 – n.a.

11/22/99 1110 WBR93 26730 Avian n.r.

11/22/99 1110 WBR93 26728 Avian E

11/22/99 1110 WBR93 26729 Rodent E

11/22/99 1110 WBR93 26731 Rodent E

11/22/99 1115 WBR94 26732 Avian E

11/22/99 1115 WBR94 26735 Bovine E, V

11/22/99 1115 WBR94 26734 Bovine E

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
Appendix 61

11/22/99 1115 WBR94 26733 – n.a.

11/22/99 1120 WBR95 26736 Bovine E, V

11/22/99 1120 WBR95 26739 Bovine E, V

11/22/99 1120 WBR95 26737 – n.a.

11/22/99 1120 WBR95 26738 – n.a.

11/22/99 1125 WBR96 26743 Avian n.r.

11/22/99 1125 WBR96 26741 Bovine E

11/22/99 1125 WBR96 26740 Dog V

11/22/99 1125 WBR96 26742 – n.a.

11/22/99 1125 WBR96B 26746 Avian E

11/22/99 1125 WBR96B 26747 Avian E

11/22/99 1125 WBR96B 26744 Human E

11/22/99 1125 WBR96B 26745 – n.a.

11/22/99 1125 WBR96C 26748 Avian E

11/22/99 1125 WBR96C 26750 Avian E

11/22/99 1125 WBR96C 26751 Horse E

11/22/99 1125 WBR96C 26749 – n.a.

01/04/00 1100 WBR97 26908 Poultry V

01/04/00 1100 WBR97 26909 Avian n.r.

01/04/00 1100 WBR97 26910 – n.a.

01/04/00 1100 WBR97 26911 Dog E

01/04/00 1105 WBR98 26912 Human E, V

01/04/00 1105 WBR98 26913 Human E

01/04/00 1105 WBR98 26914 Duck E

01/04/00 1105 WBR98 26915 Feline E

01/04/00 1110 WBR99 26916 – n.a.

01/04/00 1110 WBR99 26917 Poultry E

01/04/00 1110 WBR99 26918 – n.a.

01/04/00 1110 WBR99 26919 Poultry E

01/04/00 1115 WBR100 26920 – n.a.

01/04/00 1115 WBR100 26921 Opossum E

01/04/00 1115 WBR100 26922 Feline E

01/04/00 1115 WBR100 26923 – n.a.

01/04/00 1120 WBR101 26924 Deer E

01/04/00 1120 WBR101 26925 Sheep E

01/04/00 1120 WBR101 26926 Poultry E

01/04/00 1120 WBR101 26927 Pig E

01/04/00 1125 WBR102 26928 Poultry E

01/04/00 1125 WBR102 26929 – n.a.

01/04/00 1125 WBR102 26930 Turkey E, V

01/04/00 1125 WBR102 26931 – n.a.

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
62 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

01/04/00 1130 WBR103 26932 Turkey E, V

01/04/00 1130 WBR103 26933 Feline E

01/04/00 1130 WBR103 26934 – n.a.

01/04/00 1130 WBR103 26935 Feline E

01/04/00 1135 WBR104 26936 Bovine E

01/04/00 1135 WBR104 26937 Bovine E

01/04/00 1135 WBR104 26938 Opossum E

01/04/00 1135 WBR104 26939 Human E

01/04/00 1135 WBR104B 26940 Bovine E

01/04/00 1135 WBR104B 26941 Dog E

01/04/00 1135 WBR104B 26942 Bovine E

01/04/00 1135 WBR104B 26943 Opossum n.r.

01/04/00 1135 WBR104C 26944 Human E, V

01/04/00 1135 WBR104C 26945 Bovine E

01/04/00 1135 WBR104C 26946 Human E

01/04/00 1135 WBR104C 26947 – n.a.

01/10/00 1003 WBR105 26972 Dog E

01/10/00 1003 WBR105 26973 Avian E

01/10/00 1003 WBR105 26974 Feline E

01/10/00 1003 WBR105 26975 Bovine E

01/10/00 1300 WBR108 26976 – n.a.

01/10/00 1300 WBR108 26977 Avian E

01/10/00 1300 WBR108 26978 – n.a.

01/10/00 1300 WBR108 26979 Feline E

01/10/00 1400 WBR111 26980 Bovine E

01/10/00 1400 WBR111 26982 Bovine E

01/10/00 1400 WBR111 26981 Coyote E

01/10/00 1400 WBR111 26983 Pig n.r.

01/10/00 1618 WBR112 26985 Avian n.r.

01/10/00 1618 WBR112 26987 Bovine E

01/10/00 1618 WBR112 26984 – n.a.

01/10/00 1618 WBR112 26986 – n.a.

01/10/00 1641 WBR113 26988 Bovine E

01/10/00 1641 WBR113 26990 Bovine E

01/10/00 1641 WBR113 26989 Coyote E

01/10/00 1641 WBR113 26991 Duck V

01/10/00 1700 WBR114 26992 Bovine E, V

01/10/00 1700 WBR114 26995 Opossum E

01/10/00 1700 WBR114 26993 Sheep E

01/10/00 1700 WBR114 26994 – n.a.

01/10/00 1715 WBR115 26998 Bovine E, V

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
Appendix 63

01/10/00 1715 WBR115 26997 Deer E

01/10/00 1715 WBR115 26996 Feline E

01/10/00 1715 WBR115 26999 Rodent E

01/10/00 1900 WBR116 27002 Bovine E

01/10/00 1900 WBR116 27003 Bovine E

01/10/00 1900 WBR116 27000 – n.a.

01/10/00 1900 WBR116 27001 – n.a.

01/10/00 2205 WBR117 27007 Dog E

01/10/00 2205 WBR117 27004 Human n.r.

01/10/00 2205 WBR117 27006 Poultry V

01/10/00 2205 WBR117 27005 – n.a.

01/10/00 925 WBR118 27009 Bovine V

01/10/00 925 WBR118 27008 Human n.r.

01/10/00 925 WBR118 27010 – n.a.

01/10/00 925 WBR118 27011 – n.a.

01/10/00 1215 WBR119 27012 – n.a.

01/10/00 1215 WBR119 27013 – n.a.

01/10/00 1215 WBR119 27014 – n.a.

01/10/00 1215 WBR119 27015 – n.a.

03/30/00 1240 WBR121 27992 Human E

03/30/00 1240 WBR121 27990 – n.a.

03/30/00 1240 WBR121 27991 – n.a.

03/30/00 1245 WBR122 27995 Avian E

03/30/00 1245 WBR122 27993 Goose E

03/30/00 1245 WBR122 27994 Human E, V

03/30/00 1250 WBR123 27998 Poultry n.r.

03/30/00 1250 WBR123 27997 Poultry V

03/30/00 1250 WBR123 27996 – n.a.

03/30/00 1250 WBR123B 28001 Avian E

03/30/00 1250 WBR123B 27999 Human E

03/30/00 1250 WBR123B 28000 Poultry n.r.

03/30/00 1250 WBR123C 28003 Dog E

03/30/00 1250 WBR123C 28002 Poultry n.r.

03/30/00 1250 WBR123C 28004 – n.a.

05/10/00 1205 WBR124 30228 Bovine E

05/10/00 1205 WBR124 30226 Deer E

05/10/00 1205 WBR124 30227 Deer E

05/10/00 1210 WBR125 30229 – n.a.

05/10/00 1210 WBR125 30230 – n.a.

05/10/00 1210 WBR125 30231 – n.a.

05/10/00 1215 WBR126 30233 Crow n.r.

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
64 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

05/10/00 1215 WBR126 30234 Dog E

05/10/00 1215 WBR126 30232 – n.a.

05/10/00 1215 WBR126B 30235 – n.a.

05/10/00 1215 WBR126B 30236 – n.a.

05/10/00 1215 WBR126B 30237 – n.a.

05/10/00 1215 WBR126C 30239 Dog E

05/10/00 1215 WBR126C 30238 – n.a.

05/10/00 1215 WBR126C 30240 – n.a.

06/14/00 1245 WBR127 31788 Avian E

06/14/00 1245 WBR127 31786 Human V

06/14/00 1245 WBR127 31787 – n.a.

06/14/00 1250 WBR128 31789 Bovine E

06/14/00 1250 WBR128 31790 Human E

06/14/00 1250 WBR128 31791 Human V

06/14/00 1255 WBR129 31792 Bovine E

06/14/00 1255 WBR129 31793 Bovine E

06/14/00 1255 WBR129 31794 Bovine E

06/14/00 1255 WBR129B 31796 Human E

06/14/00 1255 WBR129B 31797 Turkey V

06/14/00 1255 WBR129B 31795 – n.a.

06/14/00 1255 WBR129C 31799 Bovine E, V

06/14/00 1255 WBR129C 31800 Goose E

06/14/00 1255 WBR129C 31798 – n.a.

06/14/00 1900 WBR130 31878 Dog E

06/14/00 1900 WBR130 31877 – n.a.

06/14/00 1900 WBR130 31879 – n.a.

06/14/00 1957 WBR131 31880 Avian n.r.

06/14/00 1957 WBR131 31882 Cat E

06/14/00 1957 WBR131 31881 – n.a.

06/14/00 2051 WBR132 31885 Poultry E, V

06/14/00 2051 WBR132 31883 – n.a.

06/14/00 2051 WBR132 31884 – n.a.

06/14/00 2122 WBR133 31886 Canine E

06/14/00 2122 WBR133 31887 – n.a.

06/14/00 2122 WBR133 31888 – n.a.

06/14/00 2143 WBR134 31889 Avian E

06/14/00 2143 WBR134 31890 Avian E

06/14/00 2143 WBR134 31891 – n.a.

06/14/00 2215 WBR135 31894 Deer E

06/14/00 2215 WBR135 31892 – n.a.

06/14/00 2215 WBR135 31893 – n.a.

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
Appendix 65

06/14/00 2235 WBR136 31895 Chicken V

06/14/00 2235 WBR136 31896 – n.a.

06/14/00 2235 WBR136 31897 – n.a.

06/14/00 2345 WBR137 31898 Avian E

06/14/00 2345 WBR137 31899 – n.a.

06/14/00 2345 WBR137 31900 – n.a.

06/15/00 220 WBR138 31903 Bovine E

06/15/00 220 WBR138 31901 Rodent E

06/15/00 220 WBR138 31902 – n.a.

06/15/00 720 WBR139 31904 – n.a.

07/18/00 1540 WBR140 33732 Raccoon E, V

07/18/00 1540 WBR140 33733 Raccoon E, V

07/18/00 1540 WBR140 33734 – n.a.

07/18/00 1545 WBR141 33735 Bovine V

07/18/00 1545 WBR141 33737 Feline E

07/18/00 1545 WBR141 33736 Raccoon E, V

07/18/00 1550 WBR142 33738 Bovine E

07/18/00 1550 WBR142 33740 Raccoon E, V

07/18/00 1550 WBR142 33739 – n.a.

07/18/00 1550 WBR142B 33742 Avian E

07/18/00 1550 WBR142B 33743 Raccoon E, V

07/18/00 1550 WBR142B 33741 – n.a.

07/18/00 1550 WBR142C 33744 – n.a.

07/18/00 1550 WBR142C 33745 – n.a.

07/18/00 1550 WBR142C 33746 – n.a.

08/17/00 1135 WBR148 34950 Sludge E

08/17/00 1135 WBR148 34949 – n.a.

08/17/00 1135 WBR148 34951 – n.a.

08/17/00 1140 WBR149 34952 Bovine E

08/17/00 1140 WBR149 34954 Poultry E, V

08/17/00 1140 WBR149 34953 – n.a.

08/17/00 1140 WBR149B 34957 Human E

08/17/00 1140 WBR149B 34955 Rabbit E

08/17/00 1140 WBR149B 34956 – n.a.

08/17/00 1145 WBR150 34958 Cat E, V

08/17/00 1145 WBR150 34959 – n.a.

08/17/00 1145 WBR150 34960 – n.a.

08/17/00 1150 WBR151 34961 Goose E

08/17/00 1150 WBR151 34962 – n.a.

08/17/00 1150 WBR151 34963 – n.a.

08/17/00 1150 WBR151B 34964 Avian E, V

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
66 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

08/17/00 1150 WBR151B 34965 – n.a.

08/17/00 1150 WBR151B 34966 – n.a.

Christians Creek

5/5/99 910 WCC07 23597 Bovine E

5/5/99 910 WCC07 23598 Sea Gull n.r.

5/5/99 915 WCC08 23600 Bovine E

5/5/99 915 WCC08 23599 Bovine E, V

5/5/99 920 WCC09 23601 – n.a.

5/5/99 920 WCC09 23602 – n.a.

5/5/99 925 WCC10 23603 Bovine V

5/5/99 925 WCC10 23604 – n.a.

5/5/99 930 WCC11 23606 Feline E, V

5/5/99 930 WCC11 23605 – n.a.

5/5/99 935 WCC12 23608 Deer E

5/5/99 935 WCC12 23607 Dog E

5/5/99 940 WCC13 23610 – n.a.

5/5/99 940 WCC13 23609 – n.a.

5/5/99 945 WCC14 23612 Dog E

5/5/99 945 WCC14 23611 Feline E

6/16/99 1515 WCC16 24238 Rodent E

6/16/99 1515 WCC16 24239 – n.a.

6/16/99 715 WCC17 24240 – n.a.

6/16/99 715 WCC17 24241 – n.a.

6/16/99 830 WCC18 24243 Human E

6/16/99 830 WCC18 24242 – n.a.

6/16/99 935 WCC19 24245 Bovine E

6/16/99 935 WCC19 24244 – n.a.

6/16/99 945 WCC20 24246 Bovine E, V

6/16/99 945 WCC20 24247 Bovine E, V

6/16/99 1000 WCC21 24249 Bovine E, V

6/16/99 1000 WCC21 24248 Bovine E, V

6/16/99 1005 WCC22 24251 Bovine E, V

6/16/99 1005 WCC22 24250 Bovine E, V

6/16/99 1010 WCC23 24252 Bovine E, V

6/16/99 1010 WCC23 24253 – n.a.

7/28/99 845 WCC30 24684 Duck E

7/28/99 845 WCC30 24685 Bovine E, V

7/28/99 850 WCC31 24686 Horse E

7/28/99 850 WCC31 24687 – n.a.

7/28/99 855 WCC32 24688 – n.a.

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
Appendix 67

7/28/99 855 WCC32 24689 Bovine V

7/28/99 900 WCC33 24690 Human E

7/28/99 900 WCC33 24691 Feline E

7/28/99 905 WCC34 24692 Bovine V

7/28/99 905 WCC34 24693 – n.a.

7/28/99 910 WCC35 24694 – n.a.

7/28/99 910 WCC35 24695 Human E

7/28/99 915 WCC36 24696 Human E

7/28/99 915 WCC36 24697 Poultry V

7/28/99 920 WCC37 24698 Human E, V

7/28/99 920 WCC37 24699 Avian E

9/6/99 410 WCC39 25169 Dog E, V

9/6/99 410 WCC39 25168 Turkey E, V

9/6/99 410 WCC39 25167 Turkey E, V

9/6/99 410 WCC39 25166 – n.a.

9/6/99 825 WCC40 25172 Bovine E

9/6/99 825 WCC40 25173 Bovine V

9/6/99 825 WCC40 25170 Bovine E

9/6/99 825 WCC40 25171 Duck V

9/6/99 1220 WCC41 25174 Bovine E

9/6/99 1220 WCC41 25176 Bovine E, V

9/6/99 1220 WCC41 25177 Poultry V

9/6/99 1220 WCC41 25175 – n.a.

9/6/99 1650 WCC42 25178 Feline E

9/6/99 1650 WCC42 25180 Horse E

9/6/99 1650 WCC42 25181 Human V

9/6/99 1650 WCC42 25179 – n.a.

9/6/99 1815 WCC43 25183 Bovine E

9/6/99 1815 WCC43 25182 Bovine V

9/6/99 1815 WCC43 25184 Bovine E, V

9/6/99 1900 WCC44 25186 Bovine E

9/6/99 1900 WCC44 25185 Dog V

9/6/99 1900 WCC44 25187 – n.a.

9/6/99 1900 WCC44 25188 – n.a.

9/6/99 1940 WCC45 25192 Avian E

9/6/99 1940 WCC45 25191 Dog E

9/6/99 1940 WCC45 25189 Human E

9/6/99 1940 WCC45 25190 – n.a.

9/6/99 2215 WCC46 25193 Avian E

9/6/99 2215 WCC46 25194 Avian E

9/6/99 2215 WCC46 25196 Poultry n.r.

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
68 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

9/6/99 2215 WCC46 25195 – n.a.

9/6/99 50 WCC47 25197 Avian E

9/6/99 50 WCC47 25199 Human E

9/6/99 50 WCC47 25198 Sea Gull E

9/6/99 50 WCC47 25200 – n.a.

9/6/99 835 WCC48 25203 Bovine E

9/6/99 835 WCC48 25204 Bovine E

9/6/99 835 WCC48 25201 Bovine E, V

9/6/99 835 WCC48 25202 Human E

9/14/99 1110 WCC54 25336 – n.a.

9/14/99 1110 WCC54 25337 – n.a.

9/14/99 1110 WCC54 25335 – n.a.

9/14/99 1110 WCC54 25334 – n.a.

9/14/99 1115 WCC55 25338 Human V

9/14/99 1115 WCC55 25339 – n.a.

9/14/99 1115 WCC55 25340 – n.a.

9/14/99 1115 WCC55 25341 – n.a.

9/14/99 1120 WCC56 25343 Goose n.r.

9/14/99 1120 WCC56 25345 – n.a.

9/14/99 1120 WCC56 25342 – n.a.

9/14/99 1120 WCC56 25344 – n.a.

9/14/99 1125 WCC57 25346 Turkey V

9/14/99 1125 WCC57 25348 – n.a.

9/14/99 1125 WCC57 25349 – n.a.

9/14/99 1125 WCC57 25347 – n.a.

9/14/99 1130 WCC58 25350 – n.a.

9/14/99 1130 WCC58 25351 – n.a.

9/14/99 1130 WCC58 25352 – n.a.

9/14/99 1130 WCC58 25353 – n.a.

9/14/99 1135 WCC59 25356 Turkey E, V

9/14/99 1135 WCC59 25355 – n.a.

9/14/99 1135 WCC59 25354 – n.a.

9/14/99 1135 WCC59 25357 – n.a.

9/14/99 1140 WCC60 25359 Human E

9/14/99 1140 WCC60 25360 – n.a.

9/14/99 1140 WCC60 25361 – n.a.

9/14/99 1140 WCC60 25358 – n.a.

9/14/99 1145 WCC61 25363 Avian E

9/14/99 1145 WCC61 25365 – n.a.

9/14/99 1145 WCC61 25362 – n.a.

9/14/99 1145 WCC61 25364 – n.a.

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
Appendix 69

10/25/99 1010 WCC62 26318 Avian n.r.

10/25/99 1010 WCC62 26321 Coyote E

10/25/99 1010 WCC62 26319 Human E

10/25/99 1010 WCC62 26320 Turkey V

10/25/99 1015 WCC63 26324 Avian n.r.

10/25/99 1015 WCC63 26323 Human V

10/25/99 1015 WCC63 26322 – n.a.

10/25/99 1015 WCC63 26325 – n.a.

10/25/99 1020 WCC64 26328 Avian n.r.

10/25/99 1020 WCC64 26327 Avian n.r.

10/25/99 1020 WCC64 26329 Chicken V

10/25/99 1020 WCC64 26326 – n.a.

10/25/99 1025 WCC65 26333 Dog E

10/25/99 1025 WCC65 26332 Human E, V

10/25/99 1025 WCC65 26330 – n.a.

10/25/99 1025 WCC65 26331 – n.a.

10/25/99 1030 WCC66 26335 Avian E

10/25/99 1030 WCC66 26336 Turkey V

10/25/99 1030 WCC66 26337 – n.a.

10/25/99 1030 WCC66 26334 – n.a.

10/25/99 1035 WCC67 26338 Avian n.r.

10/25/99 1035 WCC67 26339 Deer E

10/25/99 1035 WCC67 26340 Opossum E

10/25/99 1035 WCC67 26341 – n.a.

10/25/99 1040 WCC68 26343 Avian n.r.

10/25/99 1040 WCC68 26344 Dog E

10/25/99 1040 WCC68 26342 Human E, V

10/25/99 1040 WCC68 26345 Human E

10/25/99 1045 WCC69A 26346 Turkey E, V

10/25/99 1045 WCC69A 26349 – n.a.

10/25/99 1045 WCC69A 26348 – n.a.

10/25/99 1045 WCC69A 26347 – n.a.

10/25/99 1045 WCC69B 26352 Avian n.r.

10/25/99 1045 WCC69B 26351 Dog E

10/25/99 1045 WCC69B 26353 Poultry E

10/25/99 1045 WCC69B 26350 Skunk V

10/25/99 1045 WCC69C 26357 Dog E, V

10/25/99 1045 WCC69C 26354 Horse E

10/25/99 1045 WCC69C 26356 Turkey E, V

10/25/99 1045 WCC69C 26355 – n.a.

11/1/99 45 WCC71 26366 Horse E

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
70 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

11/1/99 45 WCC71 26365 Horse E

11/1/99 45 WCC71 26367 Human V

11/1/99 45 WCC71 26368 – n.a.

11/1/99 900 WCC72 26371 Dog E

11/1/99 900 WCC72 26370 Duck V

11/1/99 900 WCC72 26372 Poultry E

11/1/99 900 WCC72 26369 – n.a.

11/1/99 1230 WCC73 26374 Deer E

11/1/99 1230 WCC73 26373 Deer E

11/1/99 1230 WCC73 26375 Human E

11/1/99 1230 WCC73 26376 Human V

11/1/99 1530 WCC74 26378 Horse E

11/1/99 1530 WCC74 26380 Horse E

11/1/99 1530 WCC74 26377 Poultry E

11/1/99 1530 WCC74 26379 Raccoon V

11/1/99 1630 WCC75 26384 Bovine E

11/1/99 1630 WCC75 26383 Human E

11/1/99 1630 WCC75 26381 – n.a.

11/1/99 1630 WCC75 26382 – n.a.

11/1/99 1700 WCC76 26386 Bovine E, V

11/1/99 1700 WCC76 26385 Horse E

11/1/99 1700 WCC76 26387 Poultry V

11/1/99 1700 WCC76 26388 – n.a.

11/1/99 1725 WCC77 26390 Avian E

11/1/99 1725 WCC77 26391 Bovine E

11/1/99 1725 WCC77 26389 Dog V

11/1/99 1725 WCC77 26392 – n.a.

11/1/99 1800 WCC79 26394 Avian E

11/1/99 1800 WCC79 26396 Dog V

11/1/99 1800 WCC79 26395 Human E

11/1/99 1800 WCC79 26393 – n.a.

11/1/99 1745 WCC80 26399 Avian E

11/1/99 1745 WCC80 26397 Avian E

11/1/99 1745 WCC80 26398 Dog E

11/1/99 1745 WCC80 26400 – n.a.

11/1/99 2015 WCC81 26403 Avian n.r.

11/1/99 2015 WCC81 26401 Human E

11/1/99 2015 WCC81 26404 Raccoon E

11/1/99 2015 WCC81 26402 – n.a.

11/1/99 920 WCC82 26408 Poultry V

11/1/99 920 WCC82 26406 Poultry V

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
Appendix 71

11/1/99 920 WCC82 26407 Sea Gull n.r.

11/1/99 920 WCC82 26405 – n.a.

11/1/99 1400 WCC83 26409 Bovine E, V

11/1/99 1400 WCC83 26412 Bovine E, V

11/1/99 1400 WCC83 26410 Dog E

11/1/99 1400 WCC83 26411 Human E

11/1/99 1200 WCC84 26436 Avian E

11/1/99 1200 WCC84 26433 Avian E

11/1/99 1200 WCC84 26435 Bovine E, V

11/1/99 1200 WCC84 26434 Dog E

11/1/99 1225 WCC85 26437 Avian E

11/1/99 1225 WCC85 26440 Deer E

11/1/99 1225 WCC85 26438 Human E

11/1/99 1225 WCC85 26439 Human E

12/6/99 1045 WCC88 26753 Avian n.r.

12/6/99 1045 WCC88 26756 Bovine E

12/6/99 1045 WCC88 26755 Goose E

12/6/99 1045 WCC88 26754 – n.a.

12/6/99 1050 WCC89 26758 Avian E

12/6/99 1050 WCC89 26759 Bovine n.r.

12/6/99 1050 WCC89 26760 – n.a.

12/6/99 1050 WCC89 26757 – n.a.

12/6/99 1055 WCC90 26763 Avian E

12/6/99 1055 WCC90 26762 Bovine E, V

12/6/99 1055 WCC90 26761 Horse E

12/6/99 1055 WCC90 26764 Horse E

12/6/99 1100 WCC91 26765 Avian E

12/6/99 1100 WCC91 26768 Bovine E, V

12/6/99 1100 WCC91 26766 Bovine E, V

12/6/99 1100 WCC91 26767 Deer E

12/6/99 1105 WCC92 26769 Human E

12/6/99 1105 WCC92 26770 – n.a.

12/6/99 1105 WCC92 26771 – n.a.

12/6/99 1105 WCC92 26772 – n.a.

12/6/99 1110 WCC93 26773 Bovine E

12/6/99 1110 WCC93 26774 Deer E

12/6/99 1110 WCC93 26775 Feline E

12/6/99 1110 WCC93 26776 – n.a.

12/6/99 1115 WCC94 26777 Dog E

12/6/99 1115 WCC94 26780 Feline E

12/6/99 1115 WCC94 26779 Sludge n.r.

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
72 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

12/6/99 1115 WCC94 26778 – n.a.

12/6/99 1120 WCC95 26784 Bovine E, V

12/6/99 1120 WCC95 26783 Bovine E, V

12/6/99 1120 WCC95 26782 Poultry V

12/6/99 1120 WCC95 26781 – n.a.

12/6/99 1120 WCC95B 26787 Bovine E, V

12/6/99 1120 WCC95B 26786 Bovine E, V

12/6/99 1120 WCC95B 26788 Feline E

12/6/99 1120 WCC95B 26785 Poultry V

12/6/99 1120 WCC95C 26789 Avian n.r.

12/6/99 1120 WCC95C 26791 Bovine E, V

12/6/99 1120 WCC95C 26792 Bovine E, V

12/6/99 1120 WCC95C 26790 – n.a.

1/18/00 1100 WCC96 27132 Turkey E, V

1/18/00 1100 WCC96 27133 Avian E

1/18/00 1100 WCC96 27134 Human E

1/18/00 1100 WCC96 27135 Dog n.r.

1/18/00 1105 WCC97 27136 Avian E

1/18/00 1105 WCC97 27137 – n.a.

1/18/00 1105 WCC97 27138 Bovine E

1/18/00 1105 WCC97 27139 Avian E

1/18/00 1110 WCC98 27140 – n.a.

1/18/00 1110 WCC98 27141 – n.a.

1/18/00 1110 WCC98 27142 Avian E

1/18/00 1110 WCC98 27143 – n.a.

1/18/00 1115 WCC99 27144 – n.a.

1/18/00 1115 WCC99 27145 – n.a.

1/18/00 1115 WCC99 27146 – n.a.

1/18/00 1115 WCC99 27147 Human n.r.

1/18/00 1120 WCC100 27148 Beaver V

1/18/00 1120 WCC100 27149 – n.a.

1/18/00 1120 WCC100 27150 – n.a.

1/18/00 1120 WCC100 27151 – n.a.

1/18/00 1125 WCC101 27152 – n.a.

1/18/00 1125 WCC101 27153 – n.a.

1/18/00 1125 WCC101 27154 – n.a.

1/18/00 1125 WCC101 27155 – n.a.

1/18/00 1130 WCC102 27156 – n.a.

1/18/00 1130 WCC102 27157 – n.a.

1/18/00 1130 WCC102 27158 Horse E

1/18/00 1130 WCC102 27159 Avian n.r.

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
Appendix 73

1/18/00 1135 WCC103 27160 – n.a.

1/18/00 1135 WCC103 27161 – n.a.

1/18/00 1135 WCC103 27162 – n.a.

1/18/00 1135 WCC103 27163 – n.a.

3/20/00 1530 WCC105 27893 Avian n.r.

3/20/00 1530 WCC105 27894 Raccoon E

3/20/00 1530 WCC105 27895 – n.a.

3/20/00 2010 WCC106 27898 Avian n.r.

3/20/00 2010 WCC106 27897 Poultry E, V

3/20/00 2010 WCC106 27896 – n.a.

3/21/00 600 WCC107 27900 Feline E, V

3/21/00 600 WCC107 27899 Raccoon E

3/21/00 600 WCC107 27901 Turkey V

3/21/00 800 WCC108 27903 Avian n.r.

3/21/00 800 WCC108 27902 Bovine E

3/21/00 800 WCC108 27904 – n.a.

3/21/00 950 WCC109 27907 Avian E

3/21/00 950 WCC109 27905 Horse E, V

3/21/00 950 WCC109 27906 – n.a.

3/21/00 1100 WCC110 27908 Human n.r.

3/21/00 1100 WCC110 27910 – n.a.

3/21/00 1100 WCC110 27909 – n.a.

3/21/00 1115 WCC111 27912 Horse E

3/21/00 1115 WCC111 27913 Human E

3/21/00 1115 WCC111 27911 – n.a.

3/21/00 1140 WCC112 27914 Human n.r.

3/21/00 1140 WCC112 27915 – n.a.

3/21/00 1140 WCC112 27916 – n.a.

3/21/00 1335 WCC113 27919 Avian E

3/21/00 1335 WCC113 27917 Human n.r.

3/21/00 1335 WCC113 27918 – n.a.

3/21/00 1815 WCC114 27922 Avian E

3/21/00 1815 WCC114 27920 Avian E

3/21/00 1815 WCC114 27921 Feline E

3/30/00 940 WCC127 28006 Avian E

3/30/00 940 WCC127 28005 – n.a.

3/30/00 945 WCC128 28007 Avian E

3/30/00 945 WCC128 28008 – n.a.

3/30/00 945 WCC128 28009 – n.a.

3/30/00 950 WCC129 28011 Avian E

3/30/00 950 WCC129 28010 Horse n.r.

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
74 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

3/30/00 950 WCC129 28012 – n.a.

3/30/00 955 WCC130 28014 Deer E

3/30/00 955 WCC130 28013 – n.a.

3/30/00 955 WCC130 28015 – n.a.

3/30/00 955 WCC130B 28019 Chicken E

3/30/00 955 WCC130B 28016 Dog E

3/30/00 955 WCC130B 28017 Dog E

3/30/00 955 WCC130C 28020 Deer E

3/30/00 955 WCC130C 28022 Dog E

3/30/00 955 WCC130C 28021 – n.a.

4/24/00 2115 WCC131 29466 Avian E

4/24/00 2115 WCC131 29467 Dog E, V

4/24/00 2115 WCC131 29468 – n.a.

4/25/00 800 WCC134 29471 – n.a.

4/25/00 800 WCC134 29470 – n.a.

4/25/00 800 WCC134 29469 – n.a.

4/25/00 1310 WCC136 29474 Avian E

4/25/00 1310 WCC136 29473 Septage n.r.

4/25/00 1310 WCC136 29472 Septage n.r.

4/25/00 1400 WCC138 29475 Turkey E

4/25/00 1400 WCC138 29477 – n.a.

4/25/00 1400 WCC138 29476 – n.a.

4/25/00 1430 WCC139 29479 Bovine E, V

4/25/00 1430 WCC139 29480 Bovine E, V

4/25/00 1430 WCC139 29478 – n.a.

4/25/00 1500 WCC140 29482 Avian E

4/25/00 1500 WCC140 29481 Human V

4/25/00 1500 WCC140 29483 Turkey V

4/25/00 1530 WCC143 29485 Dog E

4/25/00 1530 WCC143 29486 Turkey V

4/25/00 1530 WCC143 29484 – n.a.

4/25/00 2200 WCC144 29489 Feline E

4/25/00 2200 WCC144 29488 Poultry E, V

4/25/00 2200 WCC144 29487 Turkey E, V

4/25/00 900 WCC145 29490 Raccoon E

4/25/00 900 WCC145 29491 – n.a.

4/25/00 900 WCC145 29492 – n.a.

4/25/00 1230 WCC148 29493 Human E

4/25/00 1230 WCC148 29495 Septage n.r.

4/25/00 1230 WCC148 29494 – n.a.

5/10/00 945 WCC151 30211 Bovine E, V

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
Appendix 75

5/10/00 945 WCC151 30213 Goose E

5/10/00 945 WCC151 30212 – n.a.

5/10/00 950 WCC152 30214 – n.a.

5/10/00 950 WCC152 30215 – n.a.

5/10/00 950 WCC152 30216 – n.a.

5/10/00 955 WCC153 30217 Crow E

5/10/00 955 WCC153 30218 – n.a.

5/10/00 955 WCC153 30219 – n.a.

5/10/00 955 WCC153B 30222 Bovine E

5/10/00 955 WCC153B 30220 Deer E

5/10/00 955 WCC153B 30221 – n.a.

5/10/00 955 WCC153C 30225 Bovine E

5/10/00 955 WCC153C 30224 – n.a.

5/10/00 955 WCC153C 30223 – n.a.

6/20/00 1135 WCC156 32012 Bovine V

6/20/00 1135 WCC156 32011 Dog E

6/20/00 1135 WCC156 32010 Duck E

6/20/00 1140 WCC157 32014 Avian E, V

6/20/00 1140 WCC157 32013 Crow n.r.

6/20/00 1145 WCC158 32015 Avian E

6/20/00 1145 WCC158 32016 Human E

6/20/00 1145 WCC158B 32018 Human E

6/20/00 1145 WCC158B 32017 – n.a.

6/20/00 1145 WCC158B 32019 – n.a.

6/20/00 1145 WCC158C 32021 Avian E

6/20/00 1145 WCC158C 32022 Feline E

6/20/00 1145 WCC158C 32020 – n.a.

6/27/00 1625 WCC160 33106 – n.a.

6/27/00 1625 WCC160 33104 – n.a.

6/27/00 1625 WCC160 33105 – n.a.

6/27/00 852 WCC162 33107 – n.a.

6/27/00 915 WCC163 33108 Fox n.r.

6/27/00 915 WCC163 33109 Fox n.r.

6/27/00 2020 WCC165 33110 Bovine E

6/27/00 2020 WCC165 33111 Goat E

6/27/00 2020 WCC165 33112 Human n.r.

6/27/00 2130 WCC166 33114 Deer E

6/27/00 2130 WCC166 33113 – n.a.

6/27/00 2215 WCC167 33115 Avian E

6/27/00 2215 WCC167 33116 – n.a.

6/27/00 30 WCC169 33117 Dog V

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source
76 Patterns and Sources of Fecal Coliform Bacteria in Three Streams in Virginia, 1999-2000

6/27/00 30 WCC169 33118 Human E, V

6/27/00 130 WCC170 33119 Bovine E

6/27/00 130 WCC170 33121 Human n.r.

6/27/00 130 WCC170 33120 – n.a.

6/27/00 430 WCC171 33122 Horse E

8/3/00 820 WCC183 34511 Deer E

8/3/00 820 WCC183 34509 – n.a.

8/3/00 820 WCC183 34510 – n.a.

8/3/00 825 WCC184 34512 Deer E

8/3/00 825 WCC184 34514 Deer E

8/3/00 825 WCC184 34513 Deer E

8/3/00 825 WCC185 34517 Avian E

8/3/00 825 WCC185 34516 – n.a.

8/3/00 825 WCC185 34515 – n.a.

8/3/00 830 WCC186 34520 Horse E

8/3/00 830 WCC186 34518 – n.a.

8/3/00 830 WCC186 34519 – n.a.

8/3/00 835 WCC187 34521 Avian E

8/3/00 835 WCC187 34523 Bovine E, V

8/3/00 835 WCC187 34522 – n.a.

8/3/00 835 WCC188 34524 Avian E

8/3/00 835 WCC188 34526 Human E

8/3/00 835 WCC188 34527 Raccoon n.r.

8/3/00 835 WCC188 34525 Raccoon n.r.

Sample

date

Sample

time

Sample

identifier

E. coli isolate

number Source Source library 

used

Appendix 1. Bacterial source tracking data from streamwater samples collected March 1999 through October 2000 

at the stream gages on Accotink Creek, Blacks Run, and Christians Creek, Virginia—Continued

[Stream-gage locations are in figures 2-4. For each water sample, 1-5 E. coli isolates were ribotyped]

Source library used: E, University of Washington Microbial Source Tracking Laboratory’s large available source 

library; V, Virginia-specific source library, which included source isolates collected during this study; n.r., source 

library used was not recorded; n.a., not applicable.

Source: For purposes of data analysis, feline was considered to be cats; canine was considered to be dogs; septage was 

considered to be human, whereas sludge, digested sludge, combined sewer overflow, and sanitary sewer were treated as 

individual categories. Transient, isolates that have been observed in more than one animal species; –, isolate that could 

not be matched to a specific source