Occurrence of Fecal-Indicator Bacteria and 

Protocols for Identification of FecalContamination Sources in Selected 

Reaches of the West Branch Brandywine 

Creek, Chester County, Pennsylvania

by Peter J. Cinotto

U.S. Department of the Interior 

U.S. Geological Survey

In cooperation with the 

Chester County Water Resources Authority and the 

Chester County Health Department

Scientific Investigations Report 2005-5039
ii 

U.S. Department of the Interior

Gale A. Norton, Secretary

U.S. Geological Survey

Charles G. Groat, Director

U.S. Geological Survey, Reston, Virginia: 2005

For sale by U.S. Geological Survey, Information Services 

Box 25286, Denver Federal Center 

Denver, CO 80225

For more information about the USGS and its products: 

Telephone: 1-888-ASK-USGS 

World Wide Web: http://www.usgs.gov/

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply 

endorsement by the U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report.

Suggested citation:

Cinotto, P.J., 2005, Occurrence of fecal-indicator bacteria and protocols for identification of fecal-contamination sources 

in selected reaches of the West Branch Brandywine Creek, Chester County, Pennsylvania: U.S. Geological Survey Scientific Investigations Report 2005-5039, 91 p.
 iii

Contents

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

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Purpose and Scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

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

Coatesville Study Reach. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Wagontown Study Reach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Previous Studies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Methods of Sample Collection and Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Collection and Analysis of Bacteria Within the Water Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Collection and Analysis of Bacteria Within Fluvial and Artificial Sediments. . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Field Chemistry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Water-Quality Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Quality Assurance / Quality Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Relation of Bacteria to the Fluvial Environment in the West Branch Brandywine Creek and

Its Tributaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Human and Environmental Factors Potentially Affecting Concentrations of Bacteria in the

West Branch Brandywine Creek and Its Tributaries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Particle Distribution of Sediments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Climatic Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Aquatic Growth in the Water Column and Sediments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Field Chemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Nutrients and Wastewater Constituents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Impervious Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Sediment and Soil Filtration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Dams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Turbidity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Potential Sources of Bacteria on Selected Reaches of the West Branch Brandywine Creek. . . . . . . . . . 35

Sediment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Storm Sewers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Bacterial Regrowth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Protocols for Assessment of Fecal Contamination Using Sandbag Samplers and Optical-Brightener 

Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Description of Method and Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Results From Trial Installation of Sandbag and Optical Brightener Samplers . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Application of Method for Assessment of Escherichia Coli and (or) Enterococci Bacteria. . . . . . . . . . . . . 38

Construction of Samplers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Installation of Samplers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Natural Sediment and Sandbag Samplers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Optical-Brightener Samplers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Equipment List for Construction and Installation of Samplers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Limitations of Samplers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
iv 

Contents—Continued

Limitations of the Investigation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45

References Cited. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45

Appendixes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

Glossary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91

Figures

1. Map showing study area on West Branch Brandywine Creek, Chester County,

Pennsylvania. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2. Photograph showing headwall of 1929 bridge that previously spanned Gibbons Run, 

Coatesville study reach. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

3-6. Maps showing:

3. Base-flow sampling sites on the Coatesville study reach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4. Stormflow sampling sites on the Coatesville study reach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

5. Sandbag sampling sites on the Coatesville study reach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

6. Base-flow sampling sites on the Wagontown study reach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

7-10. Photographs showing:

7. U.S. Geological Survey personnel collecting bacteria sample from the water column 

in the West Branch Brandywine Creek, Chester County, Pennsylvania. . . . . . . . . . . . . . . . . . . . . . 12

8. U.S. Geological Survey personnel collecting bacteria sample from fluvial sediments 

in the West Branch Brandywine Creek, Chester County, Pennsylvania. . . . . . . . . . . . . . . . . . . . . . 12

9. U.S. Geological Survey personnel recording field-chemical measurements in 

Coatesville study reach, 2002, West Branch Brandywine Creek, Chester 

County, Pennsylvania. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

10. Sand-gauge card used for visual estimation of sediment particle size . . . . . . . . . . . . . . . . . . . . . . . 15

11-12. Boxplots of:

11. Distribution of Escherichia coli influvial sediment, by particle-size range . . . . . . . . . . . . . . . . . . . . 16

12. Distribution of enterococci in fluvial sediment, by particle-size range . . . . . . . . . . . . . . . . . . . . . . . . 17 

13-19. Graphs showing:

13. Escherichia coli in fluvial sediment, Coatesville study reach, 2002 and 2003 . . . . . . . . . . . . . . . . . . 18

14. Escherichia coli in the water column, Coatesville study reach, 2002 and 2003. . . . . . . . . . . . . . . . 18

15. Escherichia coli and turbidity in the water column during base-flow conditions, 

Coatesville study reach, 2002. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

16. Escherichia coli and turbidity in the water column during base-flow conditions, 

Coatesville study reach, 2003. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

17. Enterococci and turbidity in the water column during base-flow conditions, 

Coatesville study reach, 2003. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

18. Specific conductance, Coatesville study reach, September 9-12, 2002. . . . . . . . . . . . . . . . . . . . . . . 21

19. Specific conductance, Coatesville study reach, July 7-9, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

20. Map showing nutrient and wastewater-constituent sampling sites, Coatesville study reach

West Branch Brandywine Creek, Chester County, Pennsylvania. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
 v

Figures—Continued

21-26. Graphs showing:

21. Escherichia coli in fluvial sediment during base-flow conditions, Coatesville study 

reach, 2002 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

22. Escherichia coli in fluvial sediment during base-flow conditions, Coatesville study reach, 

2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

23. Escherichia coli and enterococci concentrations in the water column during 

base-flow conditions, Wagontown study reach, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

24. Escherichiacoli and enterococci concentrations in the water column during base-flow 

conditions, Coatesville study reach, 2003. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

25. Fecal coliform and fecal streptococci concentrations in fluvial sediment during 

base-flow conditions, Wagontown study reach, 2002 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

26. Escherichia coli and enterococci concentrations in fluvial sediment during base-flow 

conditions, Wagontown study reach, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

27-29. Photographs showing:

27. Dam at station 0 on Coatesville study reach, West Branch Brandywine Creek. . . . . . . . . . . . . . . 30

28. Dam at station 2,500 on Coatesville study reach, West Branch Brandywine Creek. . . . . . . . . . . 30

29. Dam at station 10,905 (dam #4) on Coatesville study reach, West Branch 

Brandywine Creek. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

30-38. Graphs showing:

30. Escherichiacoli and turbidity in the water column during base-flow conditions, 

Coatesville study reach, 2002 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

31. Escherichia coli and turbidity in the water column during base-flow conditions, 

Coatesville study reach, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

32. Enterococci and turbidity in the water column during base-flow conditions, 

Coatesville study reach, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

33. Relation between base flow turbidity and Escherichia coli bacteria within Coatesville 

study reach, 2002 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

34. Relation between base flow turbidity and Escherichia coli bacteria within Coatesville 

study reach, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

35. Relation between stormflow turbidity and Escherichia coli bacteria within Coatesville 

study reach, 2002 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

36. Relation between stormflow turbidity and Escherichia coli bacteria within Coatesville 

study reach, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

37. Relation between turbidity and Escherichia coli bacteria within Coatesville and 

Wagontown study reaches, 2002-03 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

38. Relation between stormflow turbidity and Escherichia coli bacteria at USGS 

streamflow-gaging station 01480617 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

39. Photograph showing sandbag and optical-brightener samplers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

40-41. Graphs shoiwng:

40. Escherichia coli concentrations in sandbags and natural fluvial sediment, 

Coatesville study reach, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

41. Graph shoiwng enterococci concentrations in sandbags and natural fluvial sediment, 

Coatesville study reach, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

42. Photograph showing mounting hardware for sandbag and optical-brightener samplers . . . . . . . . . . 39
vi 

Table

1. Sample-processing protocols for collected bacteria samples from the West Branch

Brandywine Creek, Chester County, Pennsylvania. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Appendix 1 - Site Descriptions

1-1. Descriptions of base-flow-sampling sites on Coatesville study reach, West Branch

Brandywine Creek, 2002 and 2003, Chester County, Pennsylvania. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

1-2. Descriptions of stormflow-sampling sites on Coatesville study reach, West Branch 

Brandywine Creek, 2002 and 2003, Chester County, Pennsylvania. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

1-3. Descriptions of base-flow-sampling sites on Wagontown study reach, West Branch 

Brandywine Creek, 2002 and 2003, Chester County, Pennsylvania. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Appendix 2 - Coatesville Study Reach Data Tables

2-1. Results of laboratory analyses and field determinations for bacteria concentrations in 

water and fluvial sediments at base flow on Coatesville study reach, West Branch 

Brandywine Creek and tributaries, September 9, 2002, to September 12, 2002, 

Chester County, Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

2-2. Results of field determinations for selected water-quality constituents at base flow on

Coatesville study reach, West Branch Brandywine Creek, September 9, 2002, to

September 12, 2002, Chester County, Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

2-3. Results of field determinations for selected water-quality constituents at flowing

tributaries to West Branch Brandywine Creek under base-flow conditions on Coatesville 

study reach, September 9, 2002, to September 12, 2002, Chester County, Pennsylvania. . . . . . . . . . . . 64

2-4. Results of laboratory analyses and field determinations for bacteria concentrations in 

water and selected water-quality constituents at stormflow on Coatesville study reach, 

West Branch Brandywine Creek and flowing tributaries, September 16, 2002, 

Chester County, Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

2-5. Results of field determinations and laboratory analyses for bacteria concentrations in 

water and fluvial sediments at base flow on Coatesville study reach, West Branch Brandywine 

Creek and tributaries, July 7, 2003, to July 10, 2003, Chester County, Pennsylvania . . . . . . . . . . . . . . . . . 66

2-6. Results of field determinations for selected water-quality constituents at base flow on 

Coatesville study reach, West Branch Brandywine Creek, July 7, 2003, to July 10, 2003, 

Chester County, Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

2-7. Results of field determinations for selected water-quality constituents at flowing tributaries

to West Branch Brandywine Creek at base flow on Coatesville study reach, July 7, 2003, to

July 10, 2003, Chester County, Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

2-8. Wastewater constituents in water at base flow on Coatesville study reach, West Branch 

Brandywine Creek, July 10, 2003. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

2-9. Nutrients in water at base flow on Coatesville study reach, West Branch Brandywine Creek, 

July 10, 2003. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

2-10. Results of laboratory analyses and field determinations for bacteria concentrations in 

water and selected water-quality constituents at stormflow on Coatesville study reach, 

West Branch Brandywine Creek and flowing tributaries, August 4, 2003, 

Chester County, Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
 vii

Appendix 2 - Coatesville Study Reach Data Tables—Continued

2-11. Wastewater constituents in water at stormflow on Coatesville study reach, West Branch

Brandywine Creek, August 4, 2003. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

2-12. Nutrients in water at stormflow on Coatesville study reach, West Branch Brandywine Creek, 

August 4, 2003. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

Appendix 3 - Wagontown Study Reach Data Tables

3-1. Results of laboratory analyses and field determinations for bacteria concentrations in 

water and fluvial sediments at base flow on Wagontown study reach, West Branch 

Brandywine Creek and tributaries, September 18, 2002, Chester County, Pennsylvania. . . . . . . . . . . . 80

3-2. Results of field determinations for selected water-quality constituents at base flow on

Wagontown study reach, West Branch Brandywine Creek, September 18, 2002, 

Chester County, Pennsylvania. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

3-3. Results of laboratory analyses and field determinations for bacteria concentrations in 

water and fluvial sediments at base flow on Wagontown study reach, West Branch 

Brandywine Creek and tributaries, July 17, 2003, Chester County, Pennsylvania. . . . . . . . . . . . . . . . . . . 82

3-4. Results of field determinations for selected water-quality constituents at base flow on 

Wagontown study reach, West Branch Brandywine Creek, July 17, 2003, Chester County, 

Pennsylvania. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Appendix 4 - Sandbag and Optical-Brightener Data Table

4-1. Descriptions of sandbag-sampling sites and laboratory determinations for bacteria 

concentrations and optical-brightener presence on Coatesville study reach, July 3, 2003 to 

July 10, 2003, West Branch Brandywine Creek, Chester County, Pennsylvania. . . . . . . . . . . . . . . . . . . . 86

Appendix 5 - 2003 Streamflow-Gaging Station 01480617

Data Table

5-1. Results of laboratory analysis and field determinations for selected water-quality 

constituents and bacteria concentrations in water at stormflow at USGS streamflowmeasurement station 01480617, West Branch Brandywine Creek at Modena,

August 4, 2003, Chester County, Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
viii 

Conversion Factors and Datum

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

°F = (1.8 × °C) + 32

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows:

°C = (°F - 32) / 1.8

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 

(NAVD 88).

Horizontal coordinate information is referenced to the North American Datum of 1988 (NAD 88). 

Altitude, as used in this report, refers to distance above the vertical datum.

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (μS/cm at 

25°C).

Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) or 

micrograms per liter (μg/L).

Concentrations of bacteria in water are given in colonies per 100 milliliters (col/100 mL), and concentrations in sediment are given in colonies per gram (col/g). 

Abbreviations used in report:

<, less than

>, greater than

mL, milliliter

g, gram

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

square foot (ft2) 0.09290 square meter (m2)

square mile (mi2) 2.590 square kilometer (km2)

Volume

gallon (gal) 3.785 liter (L)

cubic foot (ft3) 0.02832 cubic meter (m3)

Flow rate

foot per day (ft/d) 0.3048 meter per day (m/d)

foot per year (ft/yr) 0.3048 meter per year (m/yr)

cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s)

Mass

pound, avoirdupois (lb) 0.4536 kilogram (kg)

Specific capacity

gallon per minute per foot [(gal/min)/ft)] 0.2070 liter per second per meter [(L/s/m]

Hydraulic conductivity

foot per day (ft/d) 0.3048 meter per day (m/d)
Occurrence of Fecal-Indicator Bacteria and Protocols

for Identification of Fecal-Contamination Sources

in Selected Reaches of the West Branch Brandywine 

Creek, Chester County, Pennsylvania

by Peter J. Cinotto

Abstract

The presence of fecal-indicator bacteria indicates the 

potential presence of pathogens originating from the fecal matter of warm-blooded animals. These pathogens are responsible 

for numerous human diseases ranging from common diarrhea to 

meningitis and polio. The detection of fecal-indicator bacteria 

and interpretation of the resultant data are, therefore, of great 

importance to water-resource managers. Current (2005) techniques used to assess fecal contamination within the fluvial 

environment primarily assess samples collected from the water 

column, either as grab samples or as depth- and (or) width-integrated samples. However, current research indicates approximately 99 percent of all bacteria within nature exist as attached, 

or sessile, bacteria. Because of this condition, most current techniques for the detection of fecal contamination, which utilize 

bacteria, assess only about 1 percent of the total bacteria within 

the fluvial system and are, therefore, problematic. Evaluation of 

the environmental factors affecting the occurrence and distribution of bacteria within the fluvial system, as well as the evaluation and modification of alternative approaches that effectively 

quantify the larger population of sessile bacteria within fluvial 

sediments, will present water-resource managers with more 

effective tools to assess, prevent, and (or) eliminate sources of 

fecal contamination within pristine and impaired watersheds. 

Two stream reaches on the West Branch Brandywine 

Creek in the Coatesville, Pa., region were studied between September 2002 and August 2003. The effects of sediment particle 

size, climatic conditions, aquatic growth, environmental chemistry, impervious surfaces, sediment and soil filtration, and 

dams on observed bacteria concentrations were evaluated. 

Alternative approaches were assessed to better detect geographic sources of fecal contamination including the use of turbidity as a surrogate for bacteria, the modification and implementation of sandbag bacteria samplers, and the use of optical 

brighteners. For the purposes of this report, sources of bacteria 

were defined as geographic locations where elevated concentrations of bacteria are observed within, or expected to enter, the 

main branch of the West Branch Brandywine Creek. Biologic 

sources (for example, waterfowl) were noted where applicable; 

however, no specific study of biologic sources (such as bacterial 

source tracking) was conducted.

Data indicated that specific bacterial populations within 

fluvial sediments could be related to specific particle-size 

ranges. This relation is likely the result of the reduced porosity 

and permeability associated with finer sediments and the ability 

of specific bacteria to tolerate particular environments. Escherichia coli (E. coli) showed a higher median concentration 

(2,160 colonies per gram of saturated sediment) in the 0.125 to 

0.5-millimeter size range of natural sediments than in other 

ranges, and enterococcus bacteria showed a higher median concentration (61,830 colonies per gram of saturated sediment) in 

the 0.062 to 0.25-millimeter size range of natural sediments 

than in other ranges. There were insufficient data to assess the 

particle-size relation to fecal coliform bacteria and (or) fecal 

streptococcus bacteria. 

Climatic conditions were shown to affect bacteria concentrations in both the water column and fluvial sediments. 

Drought conditions in 2002 resulted in lower overall bacteria 

concentrations than the more typically wet year of 2003. E. coli

concentrations in fluvial sediment along the Coatesville study 

reach in 2002 had a median concentration of 92 colonies per 

gram of saturated sediment; in 2003, the median concentration 

had risen to 4,752 colonies per gram of saturated sediment. 

Symbiotic relations between bacteria and aquatic growth 

were likely responsible for increased bacteria concentrations 

observed within an impoundment area on the Coatesville study 

reach. This reach showed evidence of elevated aquatic growth 

and sharp increases in E. coli concentrations from upstream to 

downstream through the impoundment area in both 2002 and 

2003. In 2003, E. coli concentrations within the waters column 

increased from 940 colonies per 100 milliliters upstream to 

6,000 colonies per 100 milliliters at the dam crest. Given that 

these bacteria likely resulted from natural bacterial regrowth, 

the use of E. coli as an indicator of fecal contamination was 

severely impaired. 

Variable environmental conditions along the West Branch 

Brandywine Creek made the common field-chemical parameters of specific conductance, temperature, pH, and dissolved 

oxygen ineffective and (or) impossible to use for the determination of inputs of fecal contamination. Extreme variations in 
2 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

chemical gradients commonly were related to the urban/industrial signature of the watershed. For example, during base-flow 

sampling in 2002, specific-conductance values exceeding 

1,000 microsiemens per centimeter observed in effluent from a 

local steel mill. This effluent raised the specific conductance 

within the West Branch Brandywine from just above 

200 microsiemens per centimeter upstream from the outfall to 

just below 500 microsiemens per centimeter downstream from 

the outfall. These chemical gradients also, likely, had an effect 

on the initial colonization of bacteria, the formation of biofilms, 

and the persistence of certain types of bacteria along the study 

reach. 

Data collected in 2003 indicated that nutrients increased 

during both base-flow and stormflow conditions along the 

Coatesville study reach. For example, during base-flow sampling in 2003, 20 pounds of phosphorus was shown to enter the 

West Branch Brandywine Creek along the Coatesville study 

reach. The largest contributors to this base-flow nutrient load 

were likely two wastewater-treatment facilities adjacent to the 

study reach. During stormflow sampling in 2003, 480 pounds of 

phosphorus was shown to enter the West Branch Brandywine 

Creek along the Coatesville study reach. Data, along with other 

research, indicated the largest contributor to this stormflow 

nutrient load was likely remobilized sediment originating from 

a large dam impoundment. These elevated nutrient concentrations were considered sufficient to promote accelerated aquatic 

growth along the reach. 

Data collected in 2003 showed that wastewater constituents entered the West Branch Brandywine Creek largely from 

urban storm-sewer systems. Samples from the primary storm 

sewer for the city of Coatesville had detections for 20 of 

69 wastewater constituents. These constituents included both 

strong and weak indicators of fecal contamination and generally 

indicated the storm-sewer system along the Coatesville study 

reach was a likely source of fecal-indicator bacteria and fecal 

contamination under base-flow conditions. By comparison, 

5 constituents were detected in samples from the upstream end 

of the reach, and 10 constituents were detected in samples from 

the downstream end of the reach. During stormflow, numbers of 

detections were similar along the entire length of the study 

reach—five in samples from the upstream end, eight in samples 

from the center of the reach, and seven in samples from the 

downstream end of the reach. These data indicate that point 

sources (such as culverts and pipes, septic systems, and wastewater-treatment facilities) are not likely the origin of bacteria 

contamination during stormflow. The bacteria concentrations 

observed during stormflow events probably result from remobilized sessile bacteria stored within fluvial sediments. In this 

case, these bacteria should not be considered indicators of current fecal contamination. 

Impervious surfaces were found to increase bacteria concentrations along the West Branch Brandywine Creek because 

contaminated runoff from impervious areas generally flows 

into, and is concentrated within, the confines of the local stormsewer system. During 2002, storm-sewer outfalls draining 

impervious areas were associated with all major locations of 

elevated bacterial concentrations (greater than 1,200 colonies 

per gram of saturated sediment) in fluvial sediments. During 

2003, wetter conditions and overall bacteria concentrations 

higher than in 2002 resulted in point sources of bacterial contamination becoming less pronounced; however, the stormsewer system, draining adjacent impervious areas, was still 

observed to be the primary source of bacteria along the reach. 

Where stormwater and (or) other runoff from these areas was 

allowed to infiltrate and (or) flow through wetland and riparian 

buffers, bacteria concentrations were not observed to be elevated above background levels commonly observed throughout 

similar areas of the same reach.

Two run-of-the-river dams along the Coatesville study 

reach were evaluated for their effects on observed bacterial concentrations. These dams were shown to have greater or lesser 

effects on bacterial concentrations depending on the size of the 

structure and the capacity of the structure to impede flows. The 

smaller upstream dam had an approximate height of 3 feet and 

showed little observed effect on measured turbidity values; 

these data indicated that the dam did not effectively impede the 

flow of water or sediment within the West Branch Brandywine 

Creek. Consequently, this small dam did not show any observed 

effect on bacterial concentrations either upstream or downstream of the structure. The larger dam, near the middle of the 

reach, had an approximate height of 20 feet and showed greater 

effects on both turbidity and bacteria concentrations. The 

capacity of the larger dam to impede flows, combined with 

nutrients entering the reach, resulted in increased biologic activity throughout the impoundment area. Within this larger 

impoundment, enterococcus bacteria populations were 

observed to decrease sharply and E. coli bacteria populations 

were observed to increase sharply as flow approached the dam 

crest. All bacteria levels were then observed to drop to background levels, in both the water column and fluvial sediment, 

immediately downstream from the dam crest. Additional study 

is required to determine the cause for this rapid die off. 

Turbidity was assessed as a potential surrogate for E. coli

bacteria. Regression analysis indicated higher turbidity levels 

usually can indicate higher concentrations of bacteria (R2 = 

0.67), but the relation was too sporadic on the West Branch 

Brandywine Creek to use turbidity as a surrogate for estimated 

bacteria concentrations. Evaluation of data from individual 

base-flow and stormflow events resulted in variable and generally poor statistical relations between E. coli bacteria and turbidity (R2 values ranged from 0.02 to 0.94). 

Sandbag samplers were used in 2003 to determine their 

suitability for the assessment of fecal contamination. Sandbag 

samplers rely on the ability of bacteria to attach to surfaces and 

use the larger sessile bacteria populations instead of the more 

commonly used planktonic bacteria populations. E. coli bacteria concentrations observed in the sandbag samplers, after 

1 week in place, were similar to those found within natural sediments collected concurrently. Enterococcus bacteria concentrations within the same sandbag samplers were not similar, and 

were generally lower, than those observed within the natural 

sediments. This discrepancy was likely because sand within the 
Introduction 3

samplers was sieved to a size that was likely too coarse for 

enterococcus bacteria to persist. 

Optical-brightener samplers were installed along with 

each sandbag sampler. Optical brighteners are additives used in 

common household detergents; therefore, detection of optical 

brighteners, along with elevated fecal-indicator bacteria concentrations, strongly indicates a link to humans. Positive results 

for optical brighteners were detected only at the outfalls of two 

sewage-treatment facilities; because of treatment of the effluent 

from these facilities, these samples did not have elevated bacteria concentrations. The lack of additional positive results was 

largely because this method is not sensitive to low concentrations of optical brighteners. 

Introduction

The presence of fecal-indicator bacteria indicates the 

potential presence of pathogens originating from the fecal matter of warm-blooded animals. These pathogens are responsible 

for numerous human diseases ranging from common diarrhea to 

meningitis and polio. Water contaminated with elevated levels 

of pathogens affects not only human health but also the economy of the surrounding region as fisheries, beaches, aesthetics, 

and water supplies are degraded. The detection of fecal-indicator bacteria and interpretation of the resultant data are, therefore, of great importance to water-resource managers. 

Current (2005) methods used to assess fecal contamination 

within the fluvial1

 environment primarily analyze samples collected from the water column, either as grab samples or as 

depth- and (or) width-integrated samples. Two problems are 

present within this methodology. First, in nature approximately 

99 percent of all bacteria are sessile or attached to surfaces 

within the environment (Potera, 1998); consequently, these bacteria are not well represented in samples from the water column 

that target primarily planktonic or free-floating bacteria. Second, direct fecal input into the fluvial system cannot explain 

widespread and consistent occurrences of bacteria within a 

watershed (Byappanahalli and others, 2003). Because of these 

problems, identification of sources of fecal contamination 

becomes problematic, and according to Nix and Merry (1990), 

current methods limit the ability to accurately and cost effectively assess the extent of fecal contamination in the fluvial 

environment. 

All bacteria, such as Escherichia coli (E. coli) and (or) 

enterococci, possess the ability to attach to inorganic and 

organic surfaces such as rocks, pipes, fish, and (or) other surfaces. Bacteria detect the surface of an object by contact and 

disturbance of the cell envelope; this disturbance causes a 

genetic change or expression that allows the cell to attach to an 

object by means of polymeric fibers that anchor it to a surface 

(Geesey and others, 2003). These sessile bacteria are genetically different from planktonic bacteria because of the adhesion-induced genetic changes (Otto and Silhavy, 2002). Bacterial species also have been shown to preferentially attach within 

different environments and with specific partners (Costerton 

and others, 1999). This condition means the attachment process 

is not completely random, and natural sessile bacterial populations are not expected to be equally distributed throughout a 

watershed. Sediment particle size, available nutrients, predation, and other factors all may be important in the attachment of 

bacteria. 

Subsequent to attachment, sessile bacteria excrete a slime 

coating and create what is known as a protective biofilm. The 

physical structure of a biofilm generally is described as patchy 

with many interstitial voids and channels that act as a circulatory system for the biofilm; water flows through these voids and 

channels delivering nutrients and exchanging metabolic products among the organisms within the biofilm (Davey and 

O’Toole, 2000). Bacteria and (or) other organisms within these 

protective biofilms have been shown by Davey and O’Toole 

(2000) and Costerton and others (1999) to function as a cooperative consortium, in a complex and coordinated manner, and to 

exhibit different patterns of gene expression within different 

regions of the biofilm. Simplified, this result means bacteria 

within biofilms can coordinate functions with other bacteria and 

(or) organisms in a symbiotic relation in which each organism 

is of benefit to the entire biofilm community. Biofilms commonly occur in nature; for example, Carol Potera (1998) stated, 

“In nature, 99 percent of all bacteria aggregate as biofilms—complex colonies composed of billions of bacteria that 

pool their resources to resist being killed by antimicrobial 

agents.” Notable examples of biofilms are the slime coating on 

fish, the slippery film on rocks in streams, and the plaque that 

builds up on teeth. Biofilms also can pose a major health risk; 

the Center for Disease Control estimates that 65 percent of 

human bacterial infections involve biofilms (Potera, 1999). 

William Costerton found that because of the protective nature 

of biofilms, approximately 1,500 times more of an antimicrobial agent is needed to kill bacteria within biofilm than planktonic bacteria (in Potera, 1998).

As part of a cooperative program between the Chester 

County Water Resources Authority, Chester County Health 

Department, and the U.S. Geological Survey (USGS), a study 

was proposed in 2001 to identify potential sources of fecal-indicator bacteria within the West Branch Brandywine Creek, gain 

a better understanding of bacteria occurrence and distribution 

within the fluvial system, and develop protocols to assist waterresource managers in the detection of point and nonpoint 

sources of fecal contamination within the fluvial system. The 

initial scientific basis of this study was ongoing research conducted by Francy and Gifford (2002) that showed beach sand 

could have higher concentrations of bacteria than the adjacent 

lake water. Thus, the decision was made to focus the study on 

the relation of bacteria to fluvial sediment and, to a lesser 

1 Words that are in bold are found in the Glossary section at the back of this report.
4 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

extent, the water column. Initially, samples were collected during the summer of 2002. A determination was made, on the 

basis of those findings, to extend the study into 2003 with the 

goal of increasing the general understanding of bacterial 

response within the fluvial environment as well as developing 

updated fecal-indicator bacteria sampling and processing protocols. The second year of data collection was completed in the 

summer of 2003. 

Purpose and Scope

This report describes the human and environmental factors 

affecting the occurrence and distribution of bacteria, identifies 

potential sources of fecal contamination, and presents modified 

sampling protocols for the detection of fecal-indicator bacteria 

in selected reaches of the West Branch Brandywine Creek. 

Sources of bacteria, for the purposes of this report, are defined 

as geographic locations where elevated concentrations of bacteria are observed within, or expected to enter, the main branch of 

the West Branch Brandywine Creek. The origins of bacteria 

from these sources are described to the fullest extent data will 

allow, for example, when analysis of wastewater constituents 

indicates an anthropogenic (human) source of fecal-indicator 

bacteria.

This study encompasses two reaches of the West Branch 

Brandywine Creek; one approximately 15,000-ft reach that 

flows through the city of Coatesville, Pa., and one approximately 2,500-ft reach that flows near Wagontown, Pa., approximately 1 mi upstream from the Coatesville reach. Samples 

were collected at various times from each of these two study 

reaches from September 2002 to August 2003 (summer and fall 

only). Samples were processed for a wide variety of constituents including E.coli, enterococcus, fecal coliform, and fecalstreptococcus bacteria; the field-chemical characteristics of 

specific conductance, pH, temperature, dissolved oxygen, and 

turbidity; and water-quality constituents including wastewater 

constituents and nutrients. In addition, in-stream samplers were 

modified from previous designs described by Nix and Merry 

(1990), installed throughout the Coatesville study reach, and 

processed for E. coli, enterococci, and optical brighteners. 

Streamflow was measured at two long-term (greater than 

30 years) USGS streamflow-gaging stations along the Coatesville study reach and at additional sampling sites as required. 

Even though individual sections of this report may only discuss 

certain data, all collected data are presented in the report appendixes. 

Description of Study Area

The West Branch Brandywine Creek in Chester County, 

Pa., is utilized heavily for water supply (potable, industrial, and 

livestock), irrigation, aesthetics, boating and fishing, wildlife 

water supply, and stocking of trout and other fish (warm-water, 

cold-water, and migratory) (Pennsylvania Department of Environmental Protection, 1999, p. 62). On the basis of these uses, 

as well as the potential for varied bacterial response to these 

uses, two stream reaches were selected for study on the West 

Branch Brandywine Creek (fig. 1). The primary study reach 

flows through a predominantly urban / industrial region in and 

below the city of Coatesville, Pa. The secondary study reach 

(less intensively sampled) is approximately 1 mi upstream from 

the Coatesville study reach; this reach flows through a predominantly forested region near Wagontown, Pa. For the purposes 

of this report, these reaches are termed the Coatesville study 

reach and the Wagontown study reach, respectively. 

Coatesville Study Reach

The Coatesville study reach is on the West Branch Brandywine Creek as it flows through the city of Coatesville, the 

Borough of South Coatesville, and the Borough of Modena, in 

Chester County, Pa. (fig. 1). This reach drains approximately 

55 mi2 and is characterized by a largely urban or industrial land 

use/land cover adjacent to the study reach; however, areas of 

light to moderate residential and forested land use /land cover 

are present through the reach. Sewer systems in this region are 

not combined, and separate sanitary- and storm-sewer systems 

are present; however, the system is old (built in the 1930s) and 

signs of interconnection were observed. The Coatesville study 

reach is dominated by a steel mill that can be readily observed 

within the stream valley that has been heavily altered by historical industrial use and urban development. Evidence of channel 

relocation and flood-plain filling exists throughout the reach. 

For example, a major tributary that flows through the city of 

Coatesville, Pa. (Gibbons Run) was completely buried sometime between 1929 and 1946 and now serves as the main stormsewer for the city of Coatesville, Pa. (fig. 2). These types of 

stream-channel relocation, burial, and modification were common practices throughout the industrial regions of Pennsylvania 

during the industrial revolution of the late 1800s and early 

1900s.
Introduction 5

Figure 1. Study area on West Branch Brandywine Creek, Chester County, Pennsylvania.
6 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

Sixty-four base-flow sampling sites (fig. 3), 15 stormflow 

sampling sites (fig. 4), and 15 sandbag sampling sites (fig. 5) 

were located throughout the approximately 15,000-ft length of 

the Coatesville study reach (for precise locations of each site, 

station numbers, descriptions, and downstream order of these 

stations are presented in appendixes 1 and 4). Base-flow sampling sites were located throughout the main channel of the 

West Branch Brandywine Creek and at the confluences of all 

tributaries, at all major outfalls, and at various springs. Stormflow sampling sites and sandbag sites were at similar locations 

but with much less density. All sites were assigned a project 

identification number (in the order they were located), a location (latitude and longitude), and a station stream distance (distance along the stream channel from the upstream end of the 

study reach in feet). All sites also were assigned USGS site 

identification numbers and all data were entered into the USGS 

National Water Information System database (NWIS) as 

required by USGS protocol. Comprehensive site data describing all sampling locations within the Coatesville study reach are 

presented in appendixes 1 and 4, and all data collected are presented within appendixes 2, 4, and 5.

Wagontown Study Reach

The Wagontown study reach is on the West Branch Brandywine Creek as it flows near the town of Wagontown, in Chester County, Pa. (fig. 1). This reach drains approximately 37 mi2

and is characterized by largely forested land cover adjacent to 

the reach with areas of light to moderate industrial and residential land use. In contrast to the Coatesville study reach, the Wagontown study reach has not been heavily altered (with the minor 

exception of various roadway construction projects such as the 

U.S. Route 30 bypass). Two regions, described as wetlands for 

the purposes of this report, are at the upstream and downstream 

ends of the Wagontown study reach. These areas were observed 

to be saturated with adjacent springs discharging through the 

streambanks into the West Branch Brandywine Creek. Both 

wetland areas are present in what appear to be abandoned (and 

partially filled in) channels resulting from the migration of the 

West Branch Brandywine Creek; no further wetland classification was completed within these areas. A light industrial facility 

that is a known historical source of untreated sewage entering 

the West Branch Brandywine Creek (D. Town, Chester County 

Health Department, oral commun., 2002) is adjacent to the 

Wagontown study reach. According to the Chester County 

Health Department, untreated sewage from this facility was discharged directly over the streambank and into the West Branch 

Brandywine Creek at irregular intervals, prior to about 2001, 

from an on-lot septic system.

Ten base-flow sampling sites were located throughout the 

approximately 2,500-ft Wagontown study reach (fig. 6); no 

storm samples were collected from this reach and no sandbag 

samplers were installed (precise locations of each site, station 

numbers, descriptions, and downstream order of these stations 

are presented in appendix 1). These sites were within the main 

channel of the West Branch Brandywine Creek and at various 

springs. All sites were assigned a USGS site identification number, a project identification number (in the order they were 

located), a location (latitude and longitude), and a station stream 

distance (distance along the stream channel from the upstream 

end of the study reach in feet). All data were entered into the 

USGS National Water Information System database (NWIS). 

Comprehensive site data for all sampling locations within the 

Wagontown study reach are presented in appendix 1, and all 

data collected are presented in appendix 3.

Previous Studies

Various studies previously collected data and (or) conducted research on fecal-indicator bacteria within the West 

Branch Brandywine Creek. An ongoing, biweekly data-collection program conducted jointly by the Chester County Health 

Department, Chester County Water Resources Authority, and 

the USGS (during warm-weather months from 1981 to the 

present) initially identified concentrations of fecal-indicator 

bacteria within the West Branch Brandywine Creek that 

exceeded the maximum acceptable concentration 

(200 col/100 mL) established by the Pennsylvania Department 

of Environmental Protection (1999). Subsequent to this detection by the biweekly program, an additional study was completed by Town (2001) that further defined stream reaches with 

elevated concentrations of fecal-indicator bacteria (greater than 

200 col/100 mL) and, consequently, potential fecal contamination. The Coatesville study reach, as described in this report, 

was one of the stream reaches identified by Town as containing 

elevated concentrations of fecal-indicator bacteria.

Figure 2. Headwall of 1929 bridge that previously spanned 

Gibbons Run, Coatesville study reach, West Branch Brandywine 

Creek, Chester County, Pennsylvania. (photograph by P.J. 

Cinotto, USGS)
Introduction 7

Figure 3. Base-flow sampling sites on the Coatesville study reach, West Branch Brandywine Creek, Chester County, 

Pennsylvania.
8 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

Figure 4. Stormflow sampling sites on the Coatesville study reach, West Branch Brandywine Creek, Chester County, 

Pennsylvania.
Introduction 9

Figure 5. Sandbag sampling sites on the Coatesville study reach, West Branch Brandywine Creek, Chester County, 

Pennsylvania.
10 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

Figure 6. Base-flow sampling sites on the Wagontown study reach, West Branch Brandywine 

Creek, Chester County, Pennsylvania.
Methods of Sample Collection and Analysis 11

Methods of Sample Collection and Analysis

Samples were collected and processed for various bacteria 

in natural fluvial sediments, artificial sediments in samplers 

(sandbags), and the water column. Field chemistry including 

temperature, dissolved oxygen, pH, turbidity, and specific conductance was determined at each sampling location. Waterquality samples were collected from six sites along the Coatesville study reach and analyzed for wastewater constituents and 

nutrients. All samples were collected and processed according 

to USGS standard techniques, presented or cited below, unless 

alternative methods were developed; all alternative methods are 

described in detail. 

Collection and Analysis of Bacteria Within the Water 

Column

Samples collected from the water column were analyzed 

for E. coli, enterococcus, fecal coliform, and fecal streptococcus bacteria using membrane filtration methods described in 

Myers and Wilde (1997) (table 1). Water samples were collected as a single-point grab sample with sterile 250-mL whirlclosure type plastic bags. The bag was submerged in the thalweg of the stream, opened, allowed to fill, quickly sealed, and 

placed on ice (fig. 7). Samples were transported within 6 hours 

to the Chester County Health Department Laboratory for filtration and analysis; all samples were incubated immediately after 

filtration. Results for all bacterial analyses are presented in the 

appendixes at the end of this report.

Collection and Analysis of Bacteria Within Fluvial and 

Artificial Sediments

Samples collected from fluvial sediments were analyzed 

for E. coli, enterococcus, fecal coliform, and fecal streptococcus bacteria using membrane filtration methods described 

above. Sediment samples were collected as single-point grab 

samples from wet, fluvial sediments exposed to flow from the 

potential fecal-contamination source in question; for example, 

from the bank or bed of a natural stream channel (fig. 8) or from 

within or near the mouth of a culvert. Sampling equipment consisted of a stainless-steel garden trowel rinsed in stream water 

before and after the collection of each sample. These samples 

were immediately placed in sterile 250-mL bags and transported on ice to the Chester County Health Department Laboratory along with samples collected from the water column.

No approved method for processing sediments for bacterial analyses is available; the method was, therefore, developed 

on the basis of discussions with numerous researchers while 

also considering the limitations of available laboratory equipment and personnel. Bacteria attach to sediments and must be 

mechanically removed. To accomplish this removal, the original sample was collected from wet sediments while attempting 

to minimize the amount of residual water transferred into the 

sterile sample bag with the sediment. This technique minimized 

the bacterial component associated with planktonic bacteria in 

the water column and focused on sessile bacteria attached to the 

sediments. Upon delivery to the Chester County Health Department Laboratory, the sediment sample was allowed to settle for 

approximately 30 minutes. After all fine sediments had settled 

out, the remaining water was decanted and discarded. Twenty 

grams of the remaining wet sediments were then added to a 

100-mL volumetric flask and sterile de-ionized water was 

added until 100 mL of total volume was reached; note that 

project limitations did not allow for the utilization of standard 

Table 1. Sample-processing protocols (from Myers and Wilde, 1997) for collected bacteria samples from the West Branch Brandywine 

Creek, Chester County, Pennsylvania.

[m-TEC, Escherichia coli media; m-E and EIA, enterococci media; m-FC, fecal coliform bacteria media; KF media, fecal-streptococcus bacteria media; 

°C, degrees Celsius]

Fecal-indicator bacteria

(and media type)

Filter size

(microns)

Ideal count range

(colonies per filter) Holding time Incubation time and temperature

Escherichia coli

(m-TEC)

0.45 20-80 6 hours 2 hours at 35.0°C and then 22 to 24 hours at 

44.5°C

(filter then transferred to urea substrate broth for 

15 to 20 minutes before counting)

Enterococci

(m-E and EIA)

.45 20-60 6 hours 48 to 50 hours at 41.5°C on m-E media. Transfer 

filter to EIA media for 20 minutes at 41.0°C 

before counting.

Fecal coliform bacteria

(m-FC)

.65 20-60 6 hours 22 to 26 hours at 44.5°C

Fecal streptococcus 

bacteria

(KF media)

.45 20-100 6 hours 48 to 50 hours at 35.5° +/− 0.5°C
12 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

buffering solutions for this dilution step; however, buffering 

solutions should be used for future analysis. This diluted mixture was shaken by hand for 45 seconds and then allowed to settle for 30 seconds; note that consistency could likely be 

improved in future analyses by implementing a wrist-action 

shaker (or equivalent) with a standardized rate of shaking. The 

resultant solution was analyzed by membrane-filtration methods, as would a water-column sample. Results for all bacterial 

analyses are presented in the appendixes at the end of the report.

The initial dilution factor for the solution created from the 

combination of natural, fluvial sediment and sterile de-ionized 

water (as noted above) was computed on the basis of the submerged specific weight (γs) of fluvial sediment (commonly 

used in sediment transport and geomorphic analyses). This dilution factor was required because, given laboratory limitations 

and the large number of samples to be processed, determining 

dilution factors by weight was impractical. Specific weight is 

defined as the weight of a material divided by the weight of the 

water it displaces; therefore, submerged specific weight of fluvial sediment is simply defined as the specific weight of quartz 

(2.65) minus the specific weight of water (1.00), or 1.65. Quartz 

is commonly used in this type of equation because it is the most 

common mineral found in fluvial sediments. On the basis of this 

submerged specific weight, the initial dilution factor was established as shown in the example below (note that the ~ symbol, 

called a tilde, means the value is approximate). Subsequent 

dilutions were simple dilutions based on the volume of water 

analyzed by routine membrane-filtration techniques (filtering 

more or less water through each filter). 

20 g of fluvial sediment / 1.65 = 

~12.12 mL of fluvial-sediment volume

100 mL of total volume - 12.12 mL fluvial sediment volume = 

~87.88 mL of water volume or ~87.88 g

20 g of fluvial sediment /107.88 g total weight (20+87.88) = 

0.185 = fraction of sample that is sediment 1.0/0.185 = 5.405 = 

dilution factor

With proper significant figures, this calculation yields an 

approximate dilution factor of 5.4 for natural, fluvial sediments.

As a check of the computed dilution factor above, a sample 

of sieved, general-purpose construction sand (0.5 - 1.0 mm) 

was saturated and allowed to drain by gravity. Ten replicates of 

this saturated, sieved sand were prepared, whereby 20 g were 

added to a volumetric flask and then diluted to 100 mL with 

sterile, de-ionized water (as would occur during normal laboratory analysis). During this process, all weights and volumes 

were closely measured. On the basis of these measurements, the 

volume of 20 g of saturated, sieved sand was determined to 

yield approximately 10.62 mL in volume with a standard deviation of 0.17 mL. Using this value in the above dilution-factor 

equation yields a dilution factor of 5.469 (or 5.5 with proper significant figures) for the sieved, saturated sand. Given that some 

level of inherent error is in this technique, this slight difference 

was considered reasonable and expected. 

Even though the method described above of processing 

natural, fluvial-sediment samples is reasonably accurate, the 

method for calculating the dilution factor potentially reduces 

precision and, likely, introduces some error into the final 

reported value of colonies of bacteria per gram of saturated sediment. The primary problem is that fluvial sediments in the 

Coatesville, Pa., region generally are not composed of a pure, 

homogeneous sand; less dense organic matter, other mineral 

types of various specific weights, and irregular particle sizes 

can and do affect the overall dilution factor. Although some precision was undoubtedly sacrificed by this method, the overall 

accuracy of the analysis for detection of fecal-indicator bacteria 

is still reliable. Because of the natural lack of homogeneity in 

bacterial populations within the environment, all bacterial analFigure 7. U.S. Geological Survey personnel collecting bacteria 

sample from the water column in the West Branch Brandywine 

Creek, Chester County, Pennsylvania. (Photograph by P.J. 

Cinotto, USGS)

Figure 8. U.S. Geological Survey personnel collecting bacteria 

sample from fluvial sediments in the West Branch Brandywine 

Creek, Chester County, Pennsylvania. (Photograph by P.J. 

Cinotto, USGS)
Methods of Sample Collection and Analysis 13

yses have an inherent lack of precision. In an attempt to increase 

the precision of the analysis and simplify sampling techniques, 

a solution was derived on the basis of the work of Nix and 

Merry (1990). In this method, fine-mesh nylon bags (made of 

nylon stockings) were filled with steam-sterilized, sieved sand 

and placed in the flow of the water column to be analyzed. This 

method will be described in detail later; however, the homogeneity (both size and composition) of the sieved sand generally 

assists in increasing the precision of the analysis. 

Field Chemistry

Chemical measurements were made for temperature, dissolved oxygen, pH, turbidity, and specific conductance at all 

sites where bacteria samples were collected. Field-chemical 

measurements were made using a YSI water-quality sonde 

(fig. 9). The water-quality sonde was calibrated daily according 

to manufacturer’s instructions and checked against standards 

before and after each calibration; all measurements with the 

water-quality sonde were recorded only after readings had stabilized. Where possible, multiple measurements were made 

from a cross section perpendicular to streamflow; however, 

where flow was limited, as from a small outfall, a single-point 

measurement was made. Multiple results from a cross section 

for temperature, turbidity, and specific conductance were averaged; the median value was used for dissolved oxygen and pH. 

Results for all field-chemical measurements are presented in the 

appendixes at the end of the report. 

Water-Quality Samples

Water samples from selected sites on the Coatesville study 

reach were analyzed during the 2003 field season to detect 

potential wastewater constituents and (or) nutrients. Samples 

from five sites were collected during base flow, and samples 

from three sites were collected during a storm event. One blank 

sample was sent to the laboratory with base-flow samples to 

detect potential “false positive” results caused by contamination 

during the sampling process. Collection and transport of these 

samples was completed following guidelines established in 

USGS Techniques of Water-Resources Investigations Reports 

(TWRI) (U.S. Geological Survey, various years) and USGS 

National Water-Quality Laboratory documentation (U.S. Geological Survey, 2003). Results for all water-quality samples are 

presented in the appendixes at the end of the report. 

Quality Assurance / Quality Control

Quality-assurance and quality-control techniques were 

applied to the collection of bacteria samples from the water column and sediments, field chemical measurements, and waterquality samples following, as possible, published USGS guidelines (U.S. Geological Survey, various years), and USGS 

National Water-Quality Laboratory documentation (U.S. Geological Survey, 2003). Some sampling procedures were created 

as part of this study and, consequently, quality-assurance and 

quality-control procedures were developed as required. Bacteria grab samples from the water column were collected utilizing 

sealed, sterile whirl-closure bags that were opened below the 

water surface; these bags were then immediately stored on ice. 

Fluvial-sediment samples were collected using a stainless steel 

trowel to scoop the fluvial-sediment samples and place them in 

the whirl-closure bags. This trowel was thoroughly washed in 

the streamwater adjacent to each site prior to sample collection; 

however, the trowel was not sterilized with bleach. Field chemistry was measured with a multi-parameter YSI water-quality 

sonde calibrated daily according to manufacturer’s specifications. Data from the sonde also were compared to a present 

water-quality monitor at USGS streamflow-gaging station 

01480617 (West Branch Brandywine Creek at Modena, Pa.) 

when samples were collected adjacent to this station. Waterquality samples were collected and sent to the USGS National 

Water-Quality Laboratory per guidelines noted above. An additional field blank sample was sent with samples from the baseflow sampling event to detect and prevent false-positive results. 

Data for the field blank sample are presented in appendix 2 

along with other sample data. Laboratory surrogates (samples 

with a known concentration of a specific analyte) also were analyzed along with wastewater samples from the West Branch 

Brandywine Creek. These recoveries (presented in percentages) 

are listed along with sample values in appendix 2 and give an 

indication of the accuracy and precision of the analysis. Other 

quality-assurance and quality-control techniques were performed at the National Water-Quality Laboratory as part of routine analysis. Data from these processes are available upon 

request from the National Water-Quality Laboratory; however, 

any sample data determined to be outside of established 

National Water-Quality Laboratory quality-control limits are 

not released from the National Water-Quality Laboratory without specific disclaimers that are noted, as applicable, throughout the text. 

Figure 9. U.S. Geological Survey personnel recording fieldchemical measurements in Coatesville study reach, 2002, West 

Branch Brandywine Creek, Chester County, Pennsylvania. 

(Photograph by P.J. Cinotto, USGS)
14 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

Relation of Bacteria to the Fluvial Environment in the West Branch Brandywine Creek 

and Its Tributaries

Human and Environmental Factors Potentially 

Affecting Concentrations of Bacteria in the West 

Branch Brandywine Creek and Its Tributaries

The West Branch Brandywine Creek, as stated above, is 

diverse; adjacent land use, chemical composition of stream 

water, geology, and (or) geomorphology all vary dramatically 

throughout the watershed. Data collected during 2002 and 

2003, as well as data from other research, indicated that particle 

distribution (grain size and sorting), moisture, symbiotic relations with other organisms, water chemistry, land cover, sediment and soil filtration, stream gradient (dams), and (or) competition for available resources all are important factors in 

bacterial contamination and the persistence of those bacteria 

within the water column and sediments of the fluvial system. 

These factors, as well as applicable data and citations, are 

described in detail below. 

The use of specific bacteria as an indicator of fecal contamination is totally dependent on the idea that these bacteria 

are only found in the presence of fecal contamination; however, 

data presented below indicate that these bacteria may be present 

within the environment independent from fecal contamination. 

Therefore, interpretation of this, or any, bacteria data must be 

tempered with knowledge of the origin, or potential origin, of 

those bacteria before they should be considered “fecal indicators.”

In effect, bacteria within the fluvial system may be 

strongly related to fecal contamination, only slightly related to 

fecal contamination (as in remobilized bacteria), or not related 

to fecal contamination at all (as in bacterial regrowth). Interpretations of any bacteria data attempting to determine fecal contamination must be based on assessment of the specific environment. For example, high bacteria concentrations with another 

indication of fecal contamination (such as a positive test for certain wastewater constituents) are likely fecal sources; if the 

inferred source is sediment resuspension, then there is less confidence because the fecal source may be no longer present or the 

source could be bacterial regrowth; and if there is an inferred 

biotic response (regrowth), then there is likely no relation to 

fecal contamination. 

Particle Distribution of Sediments

Fluvial sediment samples were collected in 2002 and 2003 

throughout the Coatesville and Wagontown study reaches (specific details are presented in appendix 2 and 3, respectively); 

these sediments were analyzed by membrane-filtration methods 

for bacteria including E. coli, enterococcus, fecal coliform, and 

fecal streptococcus bacteria. The dominant particle size was 

visually estimated for each sample by use of a commercially 

available sand-gauge card (fig. 10). Sand-gauge cards commonly are used in geomorphic and sediment-transport studies 

and generally provide a reliable estimation of particle size; 

however, it should be noted that the precision and accuracy of 

these determinations is less than would be obtained by sieve 

analysis. Of all fluvial-sediment samples collected, 116 were 

analyzed for E. coli, 55 were analyzed for enterococci, 10 were 

analyzed for fecal coliform bacteria, and 10 were analyzed for 

fecal streptococcus bacteria. Sample populations were too small 

to make conclusions about fecal coliform bacteria and fecal 

streptococcus bacteria concentrations within specific particlesize ranges; however, E. coli bacteria had higher median concentrations in the particle-size range of 0.125 to 0.5 mm (fine to 

medium sand) than in other particle-size classes (fig. 11), and 

enterococcus bacteria had higher median concentrations in the 

particle-size range of 0.062 to 0.25 mm (silt and clay to fine 

sand) than in other particle-size classes (fig. 12).

It must be noted that the sample populations within certain 

particle-size ranges were small (as noted by the number of 

observations presented in figures 11 and 12, respectively) and, 

therefore, statistically limited; for example, only 1 E. coli sample fell within the 2-4 mm particle size range. These small sample populations were largely because the natural particle distribution within the fluvial environment is driven by the energy 

available to transport the particles; therefore, different streams 

will have different sediment characteristics as will different 

reaches along the same stream. For example, if a stream is steep 

and fast, and generally capable of washing away all the fine sediment, one would expect to find few fine sediments in any of the 

samples. Further data are, therefore, required from other fluvial 

environments to refine the present data sets and also determine 

if a broad comparison between fluvial systems is possible or if 

these data are valid only for the West Branch Brandywine 

Creek. Also of note is that whereas the quartile distributions for 

the E. coli data set were visually similar; the quartile distributions for the enterococci data set were visually varied. This type 

of quartile variation (as observed by comparing the enterococci 

data presented in figure 12 to the E. coli data presented in 

figure 11) generally indicates a less significant relation among 

the means of each particle-size range and, therefore, these data 

should be interpreted with caution; however, no specific statistical tests were performed to validate this. Whereas a larger, 

future enterococci data set may reduce this problem, the variation observed within these data sets indicates that enterococci 

species may simply have more natural variation in the environments they prefer to colonize than do E. coli. Due in part to 

these small populations, variable data, and lack of statistical 

analyses, comparisons of particle-size classes, for example, 

comparing E. coli and enterococci concentrations within the 

0.125 to 0.5 mm particle-size range, must be considered in 

absolute terms and used with great caution. 

Data collected during this study indicate that particle distribution (grain size) is a potential factor affecting bacteria concentrations within fluvial sediments; other studies also have 

suggested similar conclusions. Studies such as Alm and others 

(2003) and Whitman and Nevers (2003) have suggested varia-
Relation of Bacteria to the Fluvial Environment in the West Branch Brandywine Creek and Its Tributaries 15

tions between bacteria concentrations may be present among 

different particle-size ranges (commonly between coarse beach 

sand and finer, deep-water, lacustrine sediments). These findings also would seem to support the findings of Davey and 

O’Toole (2000) that showed biofilms require water to flow 

through interstitial voids in order to supply nutrients and 

remove waste; any such flow would be severely impaired by the 

reduction in porosity and permeability associated with finer 

sediments. Conversely, very coarse sediments may not provide 

sufficient protection from the environment to allow the persistence of a substantial concentration of bacteria; for example, 

with too much exposure, bacteria may be subject to the effects 

of sunlight inactivation, protozoan grazing, and (or) other 

effects (Alm and others, 2003). 

Climatic Conditions

Rainfall and the subsequent streamflows during 2002 were 

at all-time lows for much of the northeastern United States 

including Chester County, Pa. The West Branch Brandywine 

Creek had the lowest flows on record during the summer of 

2002. Comparison of the streamflows during base-flow sampling in 2002 to the Q7-10 statistic (7-day, 10-year low-flow statistic or the average minimum streamflow expected for 

7 consecutive days once every 10 years) illustrated the conditions under which the samples were collected. The Q7-10 for 

USGS streamflow-gaging station 01480500 (West Branch 

Brandywine Creek at Coatesville, Pa.) was 7.7 ft3/s as of October 2003; the streamflows during base-flow sampling in 2002 

ranged from only 4.4 ft3/s on September 12, 2002, to 6.5 ft3/s 

on September 18, 2002. Base-flow sampling in 2003 took place 

during a more typical year with streamflows ranging from 40 to 

71 ft3/s along the same reach of stream. 

Figure 10. Sand-gauge card used for visual estimation of sediment particle size. (Photograph by P.J. Cinotto, USGS)
16 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

(7) (23) (21) (1) (2) (12) (18) (32)

PARTICLE SIZE RANGE, IN MILLIMETERS

1

1,000,000

2

5

10

20

50

100

200

500

1,000

2,000

5,000

10,000

20,000

50,000

100,000

200,000

500,000

ESCHERICHIA COLI, IN COLONIES PER GRAM OF SATURATED SEDIMENT

EXPLANATION

25TH PERCENTILE

MEDIAN

75TH PERCENTILE

INTERQUARTILE RANGE OUTSIDE THE QUARTILE

DATA VALUE LESS THAN OR EQUAL TO 1.5 TIMES THE

INTERQUARTILE RANGE OUTSIDE THE QUARTILE

AND MORE THAN 1.5 TIMES THE

OUTLIER DATA VALUE LESS THAN OR EQUAL TO 3

(7) NUMBER OF OBSERVATIONS

ESCHERICHIA COLI DISTRIBUTION

Figure 11. Distribution of Escherichia coli in fluvial sediment, by particle-size range, West Branch Brandywine 

Creek, Chester County, Pennsylvania.

<0.062 0.062-0.125 0.125-0.25 0.25-0.5 0.5-1 1-2 2-4 4-5.7

< LESS THAN
Relation of Bacteria to the Fluvial Environment in the West Branch Brandywine Creek and Its Tributaries 17

(1) (9) (11) (5) (10) (19)

100

10,000,000

200

500

1,000

2,000

5,000

10,000

20,000

50,000

100,000

200,000

500,000

1,000,000

2,000,000

5,000,000

EXPLANATION

(1)

Figure 12. Distribution of enterococci in fluvial sediment, by particle-size range, West Branch 

Brandywine Creek, Chester County, Pennsylvania.

<0.062 0.062-0.125 0.125-0.25 0.25-0.5 0.5-1 1-2

25TH PERCENTILE

MEDIAN

75TH PERCENTILE

INTERQUARTILE RANGE OUTSIDE THE QUARTILE

DATA VALUE LESS THAN OR EQUAL TO 1.5 TIMES THE

INTERQUARTILE RANGE OUTSIDE THE QUARTILE

AND MORE THAN 1.5 TIMES THE

OUTLIER DATA VALUE LESS THAN OR EQUAL TO 3

NUMBER OF OBSERVATIONS

ENTEROCOCCI DISTRIBUTION

PARTICLE SIZE RANGE, IN MILLIMETERS

ENTEROCOCCI, IN COLONIES PER GRAM OF SATURATED SEDIMENT

< LESS THAN
18 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

Concentrations of E. coli within fluvial sediments of the 

Coatesville study reach were generally higher under base-flow 

conditions in 2003 (median concentration of 4,752 col/g of saturated sediment) than in 2002 (median concentration of 

92 col/g of saturated sediment) (fig. 13). These findings are 

related to research conducted by Byappanahalli and others 

(2003) that showed a strong positive correlation between moisture content in sediment and bacteria concentrations. Whereas 

not substantiated by this study, the increased moisture (likely 

the increased duration of wetted periods) of the bank materials 

and overbank regions likely has some positive effect on bacteria 

concentrations within the localized region of the active stream 

channel. 

Concentrations of bacteria in the water column also were 

substantially higher in the West Branch Brandywine Creek 

under base-flow conditions in 2003 than in 2002 (fig. 14). 

Numerous studies, such Gregory and Frick (2000), have indicated that wetter antecedent conditions (more rainfall) elevate

Figure 13. Escherichia coli in fluvial sediment, 

Coatesville study reach, 2002 and 2003, West 

Branch Brandywine Creek, Chester County, 

Pennsylvania.

Figure 14. Escherichia coli in the water 

column, Coatesville study reach, 2002 and 

2003, West Branch Brandywine Creek, 

Chester County, Pennsylvania.
Relation of Bacteria to the Fluvial Environment in the West Branch Brandywine Creek and Its Tributaries 19

bacteria concentrations within the fluvial system; although 

more data are required to substantiate these findings, wetter climatic conditions will also likely result in higher bacteria concentrations throughout the fluvial environment of the West 

Branch Brandywine Creek.

It should be noted that runoff patterns from the surrounding watershed undoubtedly affect bacteria concentrations 

within the water column under any given climatic condition; 

however, mobilization of stream sediments containing elevated 

bacteria concentrations likely adds to this bacteria load. Given 

this condition, storm events during wet periods can likely mobilize (erode) these more highly contaminated sediments from 

near-bank regions and, thus, cause wet-period storm samples 

from the water column to have higher concentrations of bacteria 

than would be expected during drier years. However, this may 

not occur consistently because, as was noted above, runoff patterns may vary from storm to storm.

Aquatic Growth in the Water Column and Sediments

As noted above, the West Branch Brandywine Creek was 

under severe drought conditions during 2002. These conditions 

had the effect of reducing the energy available within the stream 

to transport sediment; thus, turbidity resulting from the transport of sediment also was reduced. The normal, large sediment 

loads of the West Branch Brandywine Creek commonly mask 

subtle variations in turbidity that may be attributed to such factors as increased aquatic growth within dam impoundments 

(J.D. Newbold, Stroud Water Research Center, oral commun., 

2003) and (or) various clear-water inputs from the numerous 

outfalls present along the reach.

During base-flow sampling in 2002 along the Coatesville 

study reach, a subtle increase in turbidity was clearly visible 

within the impoundment of a relatively large, run-of-the-river 

dam (locally known as Dam #4) (fig. 15). This subtle increase 

ranged from 3 NTU (nephelometric turbidity units) above the 

dam to 5 NTU at the dam crest. Along with the increased turbidity attributed to increased aquatic growth, a sharp increase in 

E. coli concentration also was measured (180 col/100 mL 

above the dam to 710 col/100 mL at the dam crest); however, 

no point sources of fecal-indicator bacteria, including appreciable populations of waterfowl, were found in or around the dam 

impoundment area. Data from the same impoundment the following year (2003) showed a more typical decrease in turbidity 

(11 NTU above the dam to 6 NTU at the dam crest) as sediment 

loads settled out in the quiescent water of the impoundment 

area. These data indicated that any increases in turbidity resulting from aquatic growth were masked by turbidity resulting 

from increased sediment loads. During 2003, however, the 

sharp increase in E. coli concentration was again observed 

through the impoundment area of Dam #4 although in a much 

higher concentration than the previous year (940 col/100 mL 

above the dam to 6,000 col/100 mL at the dam crest) (fig. 16). 

The repetition of the elevated concentration of E. coli within the 

dam impoundment indicated that similar processes were taking 

place in 2002 and 2003 regardless of variations in turbidity. 

Research conducted by McFeters and others (1978) studied the causes of elevated bacteria concentrations in an unpolluted, pristine stream in Wyoming; their data showed populations of various coliform bacteria increased from 2 to 3 orders 

of magnitude at 13°C when grown in sterile algal supernatant 

(Chlorella). Similarly, research by Whitman and others (2003) 

showed E. coli and enterococci were ubiquitous in algal mats 

along Lake Michigan beaches, and these bacteria could survive 

over 6 months in sun-dried algal mats stored at 4°C. Each of 

these studies suggested algal growth may be related to an 

important natural source of bacteria and that the increased concentrations of E. coli observed within the impoundment area of 

Dam #4 may be simply because of an associated increase in 

algal growth and not fecal contamination. It should be noted 

that this theory is not widely accepted; some researchers (D.S. 

Francy, U.S. Geological Survey, oral commun., 2003) sugFigure 15. Escherichia coli and turbidity in the 

water column during base-flow conditions, 

Coatesville study reach, 2002, West Branch 

Brandywine Creek, Chester County, 

Pennsylvania.
20 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

gested such bacterial regrowth is not likely and that the 

observed, elevated bacteria concentrations were simply because 

of direct fecal inputs from unidentified sources. Additional 

study would be required to confirm the presence or absence of 

bacterial regrowth within the impoundment area of Dam #4.

Samples from the impoundment area of Dam #4 also were 

processed for enterococcus bacteria in 2003. Analysis of these 

data showed that, while E. coli concentrations increased 

through the dam impoundment area, enterococci concentrations 

decreased sharply (fig. 17). These findings suggest that different processes were acting on enterococci and E. coli within the 

impoundment area of Dam #4. Whitman and others (2003) 

found, conversely, that enterococci and E. coli increased in a 

similar manner within algal mats in Lake Michigan (the algae 

was mostly Cladophora glomerata). Assuming bacterial 

regrowth is possible and is taking place within this impoundment, these data indicated an algae/ bacteria symbiotic relation, 

similar to that found in Lake Michigan, may not be present 

within the impoundment area of Dam #4. It must be noted, however, that other factors, such as predation, may have also lead to 

the observed decrease in the enterococci population within the 

impoundment area of Dam #4. Predation is a common cause of 

selective bacterial population decreases (Banning and others, 

2003) and, therefore, the observed decreases in the population 

of enterococci may have been simply because of this process. 

Whereas further study is required to accurately define these processes, the different response exhibited by E. coli and enterococci within the same environment indicates a strong correlation between the two bacterial populations is unlikely within the 

West Branch Brandywine Creek. 

Figure 16. Escherichia coli and turbidity in 

the water column during base-flow 

conditions, Coatesville study reach, 2003, 

West Branch Brandywine Creek, Chester 

County, Pennsylvania.

Figure 17. Enterococci and turbidity in the 

water column during base-flow 

conditions, Coatesville study reach, 2003, 

West Branch Brandywine Creek, Chester 

County, Pennsylvania.
Relation of Bacteria to the Fluvial Environment in the West Branch Brandywine Creek and Its Tributaries 21

Field Chemistry

Because of the wide variation in land use and associated 

water use within the watershed, the West Branch Brandywine 

Creek has extremely variable chemical gradients (changes over 

distance) that make common field-chemical measurements 

(temperature, pH, specific conductance, DO, and turbidity) 

ineffective and (or) impossible to use for the determination of 

inputs of fecal contamination. Widely variable chemical gradients commonly mask more subtle indications of sewage inputs 

from sanitary and (or) storm sewers, ground-water discharges 

from springs, and (or) other indications of flows entering the 

stream channel. These chemical gradients generally are caused 

by the industrial signature of the watershed, natural effects of 

light and temperature throughout the course of a day, and (or) 

inputs from urban and residential areas. One notable example is 

the specific-conductance signature through the stream reach 

dominated by the ISG Plate Inc., steel mill. Specific conductance is sometimes used (in conjunction with other methods) as 

an indicator of sewage inputs into the fluvial system because 

untreated wastewater generally has higher specific conductance 

than natural surface waters. However, within the Coatesville 

study reach, up to 400,000,000 gal of water per year are withdrawn from the West Branch Brandywine Creek and, to a much 

lesser extent, local tributaries for use within the ISG Plate Inc., 

steel mill (R. Ajalli, ISG Plate Inc., oral commun., 2003). This 

water is withdrawn primarily from the impoundment area of 

Dam #4, used as process water for various applications, treated 

to meet required water-quality standards, and discharged back 

into the West Branch Brandywine Creek approximately 6,500 ft 

upstream from the intake. This water, in effect, enters a loop 

and, especially during drought years, may be used repeatedly 

before finally being released downstream. Whereas this process 

water meets all required State and Federal standards for water 

quality and is closely monitored (R. Ajalli, ISG Plate Inc., oral 

commun., 2003), it is still notably different from natural waters 

within the West Branch Brandywine Creek and easily masks 

any small sewage inputs. Specific conductance throughout the 

Coatesville study reach during the drought of 2002 and during 

2003, when higher flows had a greater dilution effect, are shown 

in figures 18 and 19, respectively.

Figure 18. Specific conductance, Coatesville study 

reach, September 9-12, 2002, West Branch 

Brandywine Creek, Chester County, Pennsylvania.

Figure 19. Specific conductance, Coatesville study 

reach, July 7-9, 2003, West Branch Brandywine 

Creek, Chester County, Pennsylvania.
22 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

Changes in chemical gradients within the fluvial environment are not only notable for their capacity to mask the direct 

input of fecal material into the fluvial system, but they may also 

have appreciable effects on the initial colonization of bacteria, 

the formation of biofilms, and the persistence of certain types of 

bacteria. For example, research by Costerton and others (1999) 

has shown that the disease Cystic Fibrosis is caused by a genetic 

defect that results in elevated salt content in the airway surface 

fluid within the lungs of humans. Although this is a seemingly 

minor problem, the elevated salt concentrations subsequently 

inhibit antimicrobial activity that then allows the colonization 

of P. aeruginosa within a biofilm. Todar (2002) also showed the 

ability of E. coli to sense the presence or absence of various 

chemicals and (or) gases within the environment and move 

towards or away from them. In summary, seemingly small 

chemical variations can have far reaching effects on the presence and (or) persistence of bacteria within the fluvial system 

and (or) other environments.

On the basis of the bacterial responses to various chemical 

signatures present within the water column (such as that shown 

by Todar (2002)), some variability observed in the location of 

elevated bacteria concentrations throughout the West Branch 

Brandywine Creek was likely because of the effects of water 

chemistry. For example, Gibbons Run and Tar Run are similar 

buried streams that serve as storm sewers throughout the 

Coatesville, Pa., region. The major difference between the two 

tributaries is that Tar Run also serves as the outfall for process 

water from the ISG Plate Inc. steel mill, and as noted above, the 

effluent from the mill is substantially different (chemically) 

from the natural waters of the West Branch Brandywine Creek 

and those of Gibbons Run. This difference in water chemistry is 

likely partially responsible for the relative lack of E. coli within 

the fluvial sediments collected from Tar Run in 2002 and 2003 

(86 and 11,880 col/g of saturated sediment, respectively) as 

compared to those collected from Gibbons Run (14,580 and 

25,920 col/g of saturated sediment, respectively). This determination was based on the fact that, while Gibbons Run exhibited 

much higher concentrations of E. coli within fluvial sediments, 

Tar Run exhibited much higher concentrations of E. coli within 

the water column (1,500 and 4,400 col/100 mL, respectively) 

than did Gibbons Run (<1 and 100 col/100 mL, respectively). It 

must be stated, however, that given the complex nature of the 

bacterial-attachment process as described above, water chemistry was likely only one factor, among many, affecting this process.

Nutrients and Wastewater Constituents

During 2003, six sites were sampled for nutrients and 

wastewater constituents along the Coatesville study reach. Five 

sites were sampled during base flow and included the upstreamand the downstream-most gaging stations on the Coatesville 

study reach (USGS sites 01480500 and 01480617, respectively); the primary storm-sewer outfall for the City of Coatesville (USGS site ID 01480550); a small natural tributary (USGS 

site 01480615); and a spring that drains a hillside known to contain residences utilizing on-lot sewage disposal systems (USGS 

site 395756075485301) (fig. 20). Three sites were sampled during a storm event and included the upstream- and downstreammost stations on the Coatesville study reach, as well as a site at 

the approximate center of the Coatesville study reach (bridge 

carrying 1st Avenue over the West Branch Brandywine Creek, 

USGS site 0148061501). All water-quality sampling sites were 

selected along the Coatesville study reach in order to target specific areas and types of discharges into the West Branch Brandywine Creek. 

USGS sites 01480500, 0148061501, and 01480617 are 

along the main channel of the West Branch Brandywine Creek 

and were selected in order to identify contaminants entering the 

Coatesville study reach from upstream and to bracket the 

upstream and downstream segments of the study reach. USGS 

site 01480550 is at the mouth of the primary storm sewer for the 

City of Coatesville, Pa. Prior to about 1940, this storm sewer 

flowed as a natural stream on the surface and was known as 

Gibbons Run; presently (2005), however, the entire stream is 

buried and flows through culverts beneath the city. Although 

the City of Coatesville and the surrounding areas utilize separate sanitary- and storm-sewer systems, these systems are older 

(about 1932) and evidence of connections between the two systems are readily apparent as storm-water runoff indicators commonly flow through the sanitary-sewer system (Richard Lutz, 

Pennsylvania-American Water Company, oral commun., 

2003). USGS site 01480615 is at a small, unnamed tributary 

that enters the West Branch Brandywine Creek near the approximate center of the Coatesville study reach. This tributary has 

two main branches that drain a steep hillside underlain by the 

Octoraro Phyllite; this geologic formation develops steep 

topography with thin soils and localized areas of losing stream 

reaches as water flows through fractures and fine granular openings within the weathered zone (Sloto, 1994). Within the drainage of this small tributary are aging residential developments, 

primarily on the east branch of the tributary, and a large monofill, or slag dump, on the west branch of the tributary. The 

monofill fills a historical stream valley as observed in Bascom 

and Stose (1932) and water originating from the monofill area 

emerges as springs, enters the main channel of the tributary, 

and, subsequently, flows into the West Branch Brandywine 

Creek. USGS site 395756075485301 is at a small spring that 

drains an area adjacent to the impoundment area of Dam #4. 

The region drained by this small spring is important because it 

contains the only known on-lot sewage disposal systems in the 

region. The presence or absence of wastewater indicators from 

this spring would potentially indicate whether the on-lot sewage 

disposal systems are, or are not, contributing to the elevated 

bacteria concentrations observed within the impoundment area 

of Dam #4. 

Analyses of water-quality samples from the water-quality 

sampling sites indicated that, during base flow, nutrients, such 

as dissolved nitrate plus nitrite nitrogen and total phosphorus 

ranged from 2.0 to 3.69 mg/L and 0.008 to 0.091 mg/L, respectively. However, a large percentage of the total nutrient load 
Relation of Bacteria to the Fluvial Environment in the West Branch Brandywine Creek and Its Tributaries 23

Figure 20. Nutrient and wastewater-constituent sampling sites, Coatesville study reach, West Branch Brandywine 

Creek, Chester County, Pennsylvania.
24 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

originated from the Coatesville region. For example, utilizing 

mean-daily streamflows from the USGS streamflow-gaging 

stations 01480500 and 01480617 (54 and 81 ft3

/s, respectively) 

to determine phosphorus loads for base-flow samples collected 

on July 10, 2003, approximately 20 lb of phosphorus passed by 

the upstream-most point on the Coatesville study reach and 

approximately 40 lb passed by the downstream-most point. The 

additional 20 lb of phosphorus present at the downstream end of 

the study reach likely originated from the two wastewater-treatment facilities along the Coatesville study reach; these types of 

facilities are commonly a source of nutrients including phosphorus. The Coatesville storm-sewer system, however, did not 

appear to add a substantial nutrient load to the West Branch 

Brandywine Creek because the phosphorus load determined 

from the 0.091 mg/L of phosphorus measured at the outfall of 

Gibbons Run (the primary storm sewer for the city of Coatesville), in conjunction with a measured discharge of 0.59 ft3/s 

originating from the Gibbons Run culvert, yielded a phosphorus 

load of only approximately 0.4 lb/d, or 2 percent, of the 20-lb 

increase observed through the study reach. 

During stormflow, a similar pattern in nutrient loads was 

present along the Coatesville study reach, although at much 

higher levels and with a greater percentage of the total load 

entering from within the Coatesville region. This pattern indicated, again, that the urban / industrial Coatesville region had a 

more substantial effect on nutrient loads within the Coatesville 

study reach than did the upstream agricultural areas. Utilizing 

mean-daily streamflows from the USGS streamflow-gaging 

stations 01480500 and 01480617 (82 and 144 ft3/s, respectively) to determine phosphorus loads for stormflow samples 

collected on August 4, 2003, approximately 150 lb of phosphorus passed by the upstream-most point in the Coatesville study 

reach and approximately 630 lb passed the downstream-most 

point. During base flow, these nutrients likely originated from 

the two wastewater-treatment facilities along the study reach; 

however, at stormflow, remobilized sediments from behind the 

three dams along the study reach (Langland and Hainly, 1997), 

along with runoff from the adjacent watershed (K. Hyer, U.S. 

Geological Survey, written commun., 2004), likely contributed 

the bulk of the increase observed in nutrient loads (nutrient concentrations are presented in detail in appendix 2). 

Regardless of the source of increased nutrients entering the 

Coatesville study reach, the observed nutrient concentrations 

generally can be described as sufficient to promote accelerated 

aquatic growth. For example, nitrate concentrations above 

0.3 mg/L are noted to cause increased plant activity (U.S. Environmental Protection Agency, 1994) and all samples collected 

within the Coatesville study reach (both base-flow and stormflow samples) had concentrations above 2.0 mg /L. The elevated nutrients within the Coatesville study reach may result in 

the increased E. coli concentrations observed within the 

impoundment area of Dam #4 because the increased nutrients 

may support increased algal growth and the resultant symbiotic 

relation that potentially drives bacterial regrowth as described 

above. 

Wastewater constituents generally indicate direct fecal 

inputs to the fluvial system such as leaking sewer pipes, failed 

septic systems, combined sewer overflows, and illegal discharges. Samples were collected concurrently with nutrient 

samples and analyzed for wastewater constituents. All wastewater constituents were given equal weight for the purposes of 

this study (all wastewater data are listed in detail in appendix 2). 

It must be noted, however, that specific wastewater constituents 

are stronger indicators of fecal contamination than others; for 

example, cotinine is a relatively strong indicator of fecal contamination (as compared to other constituents) but caffeine can 

enter the environment either through wastewater or from urban 

runoff (spilled coffee running off urban parking lots is a potential source of caffeine). 

Wastewater constituents during base flow in 2003 primarily originated from the Coatesville storm-sewer system. Gibbons Run (the primary storm sewer for the City of Coatesville) 

tested positive for 20 of 69 wastewater constituents including 

strong indicators of fecal contamination such as cotinine. By 

comparison, only 5 of 69 constituents were detected entering 

the upstream end of the study reach in the main channel of the 

West Branch Brandywine Creek. These findings were consistent with data that showed the majority of sites with elevated 

bacteria concentrations within fluvial sediments along the 

Coatesville study reach were at, or near, various storm-sewer 

outfalls. Water sampled from the downstream end of the study 

reach tested positive for 10 of 69 constituents suggesting that 

dilution had lowered many of the contaminant levels entering 

from the Coatesville storm sewer to below the method detection 

limit for the various wastewater constituents. Waters originating from the small unnamed tributary and the small spring 

draining the area adjacent to Dam #4 tested positive for 7 and 3 

of 69 constituents, respectively, and, therefore, also were not 

likely introducing substantial concentrations of bacteria into 

West Branch Brandywine Creek as the result of human-related 

sewage inputs. 

During stormflow, large amounts of suspended sediments 

within the water column made analysis of certain wastewater 

constituents by gas chromatography/mass spectrometry 

(GC/MS) difficult, and surrogate recoveries for this method 

commonly were poor (these data are presented in appendix 2). 

On the basis of these surrogate recoveries, reporting limits for 

certain constituents analyzed by the GC/MS method were 

raised based on the discretion of the analyst. However, for all 

constituents, a qualitative determination was possible that, subsequently, allowed for basic evaluation of the data (for example, 

more confident of detections than non-detections) (S. Smith, 

U.S. Geological Survey, oral commun., 2004). On the basis of 

the results of these analyses, 5 of 69 constituents were detected 

at the upstream end of the study reach, 8 of 69 constituents were 

detected at the center of the study reach, and 7 of 69 constituents 

were detected at the downstream end of the study reach. These 

data indicated no substantial increase in the detected number of 

wastewater constituents along the Coatesville study reach during stormflow and suggested that point sources (culverts, pipes, 

and others) of fecal contamination within the Coatesville study 
Relation of Bacteria to the Fluvial Environment in the West Branch Brandywine Creek and Its Tributaries 25

reach probably were not the predominant origin of elevated bacteria concentrations commonly observed during stormflow on 

the West Branch Brandywine Creek. By reducing the likelihood 

that point sources (culverts, septic systems, wastewater-treatment facilities, and other sources) are the predominant source of 

bacteria during stormflows, these data lend support to the findings that elevated bacteria concentrations during stormflows are 

likely the result of remobilized sessile bacteria stored within 

fluvial sediments. (It must be noted here that bacteria washed 

from the land surface of the surrounding watershed must always 

be considered in this and other scenarios until further study, 

such as bacterial source tracking, can definitively eliminate this 

potential source.) This finding becomes important in that if the 

source of these bacteria is likely from remobilized sediments, 

these bacteria cannot be strongly linked to fecal contamination 

and should not generally be considered strong indicators of current fecal contamination.

Impervious Surfaces

The effect of impervious surfaces on bacterial contamination was most evident during 2002. The drought of that year was 

associated with a general decrease in bacteria throughout the 

watershed, as noted above, and also forced any runoff to enter 

the stream primarily by way of the existing storm-sewer system 

(desiccated soils result in the infiltration and storage of smaller 

runoff events). Likely because of this effect, elevated concentrations of E. coli in 2002 were found primarily in sediments at 

or near storm-sewer outfalls along the Coatesville study reach 

(although not all storm sewers exhibited elevated bacterial concentrations). The storm sewers with elevated bacteria concentrations drained not only the urban and residential areas of the 

City of Coatesville but also industrial areas such as the ISG 

Plate Inc., steel mill and other adjacent facilities (elevated bacteria concentrations within the sediments surrounding industrial 

storm-sewer outfalls were likely because of the large populations of rodents, bats, birds, and other animals that commonly 

were observed living within the aging industrial complexes in 

the region and also within the storm sewers themselves (James 

O’Brien, ISG Plate Inc., oral commun., 2002)). 

As observed in figure 21, sites with elevated E. coli concentrations within fluvial sediments were generally in the 

upstream region of the Coatesville study reach. This upstream 

region contains most of the known storm-sewer outfalls that 

directly enter the West Branch Brandywine Creek (from the 

City of Coatesville and the ISG Plate Inc. facility). Downstream 

storm sewers, originating largely from the smaller Borough of 

Modena, generally drain less-paved areas and flow into wetland 

or overbank areas prior to entering the West Branch Brandywine Creek. These findings were also consistent with those of 

Tufford and Marshall (2002) in a study of Rawls Creek, S.C., in 

which data indicated catchments with the largest contiguous 

impervious areas were, statistically, the greatest sources of fecal 

coliform bacteria.

The effects of impervious surfaces were not as pronounced 

during 2003 as in 2002. Even though 2003 was noted by a general increase in all bacteria levels, the primary reasons for the 

general inability to easily detect localized areas of increased 

bacterial concentrations were largely attributed to two potential 

factors: more points of direct access to the stream channel by 

planktonic bacteria (swales, drains, and (or) other points of 

entry) and more storms or “flushing events” to redistribute 

sessile bacteria throughout the reach. Better access for planktonic bacteria was largely attributed in that the soil throughout 

the region generally was saturated, or close to saturated, and 

smaller overland flows and throughflows were observed to 

reach the stream (as noted by water-filled swales and flowing 

springs that were not present in 2002). Consequently, planktonic bacteria also could be washed into the stream at multiple 

points and were not confined to the storm-sewer outfalls as in 

2002. Areas within the fluvial environment that were prone to 

colonization of sessile bacteria and were not subjected to eroFigure 21. Escherichia coli in fluvial sediment 

during base-flow conditions, Coatesville study 

reach, 2002, West Branch Brandywine Creek, 

Chester County, Pennsylvania.
26 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

sion in 2002 were subsequently vulnerable to erosion by the 

high base flow and storm events in 2003. These bacteria were 

then able to be redistributed throughout the reach in 2003; in 

2002, they were confined to isolated areas (such as storm-sewer 

outfalls). While sampling sites with elevated bacteria levels in 

2003 were still generally concentrated in the upstream region of 

the Coatesville study reach (among the storm-sewer outfalls as 

shown in figure 22), certain locations could not be directly 

related to these storm-sewer outfalls as in 2002. 

During 2003, high concentrations of bacteria were 

observed within the sediments of the West Branch Brandywine 

Creek below the outfall of the Pennsylvania-American Water 

Company wastewater-treatment facility (approximately 

4,853 ft from the upstream end of the study reach to approximately 7,747 ft). Concentrations of E. coli in fluvial sediments 

along this reach were as high as 100 times greater than the 

median concentration of the Coatesville study reach; however, 

bacteria concentrations within this stream reach during the previous year did not exceed levels that would be considered background. The origin of these bacteria was unknown; however, 

interpretation of data, based on field observations and available 

research, indicated three possible origins; the PennsylvaniaAmerican Water Company wastewater-treatment facility, 

waterfowl, and (or) storm-sewer outfalls adjacent to the reach. 

The first possible origin of the bacteria was the Pennsylvania-American Water Company wastewater-treatment facility. 

The sanitary and storm-sewer systems of Coatesville, Pa., are 

not combined, theoretically eliminating the problems commonly associated with combined-sewer overflows (CSO). 

However, this is an older system (the wastewater-treatment 

facility was constructed in 1932) with numerous leaks and 

undocumented hook-ups that, in effect, make the system function as a combined system. For example, as noted above, wastewater constituents that indicate the presence of sewage were 

detected within the storm-sewer system. Also noted were 

increased water volumes within the sanitary-sewer system containing storm-water runoff products during various storm 

events (Richard Lutz, Pennsylvania-American Water Company, oral commun., 2003). However, the Pennsylvania-American Water Company wastewater-treatment facility was 

upgraded so that if the increased volume of water in the sanitary-sewer system, during a storm, exceeded the capacity of the 

plant, untreated wastewater would not be discharged into the 

West Branch Brandywine Creek but would be diverted into a 

lined holding basin to be immediately treated when volumes 

returned to normal. According to staff of the PennsylvaniaAmerican Water Company, all exceedences in 2002 and 2003 

were contained within the holding basin and would, therefore, 

not have been the cause of the elevated bacteria observed downstream. This report is consistent with data that showed an E. coli 

concentration of only slightly above 2,000 col/g of saturated 

sediment within the sediments directly below the outfall of the 

wastewater-treatment facility in 2003. 

The second possible source of the bacteria was waterfowl. 

Staff from the wastewater-treatment facility observed a large 

population of Canada geese in the grassy areas surrounding 

their aeration tanks in the days prior to base-flow sampling; it is 

possible that, because of the saturated condition of the soil and 

the paved nature of the overbank area, some fecal matter could 

have been washed directly into the creek from these overbank 

areas without being subject to infiltration and soil filtration as 

would occur in a drier year. Although not substantiated by this 

study, waterfowl generally are not considered a major source in 

this case because the concentrations of E. coli found within the 

fluvial sediments of this reach are probably too large to originate from this source alone (nearly 500,000 col/g of saturated 

sediment at one site). Any fecal matter originating from these 

geese would have likely been dispersed during transport to the 

stream, thus, reducing the total amount of bacteria available to 

enter the stream channel at any given time. 

The third possible source, or sources, were the stormsewer outfalls just downstream from outfall for the Pennsylvania-American Water Company wastewater-treatment facility 

(project identification numbers CB25TC and CB29TC). The 

Figure 22. Escherichia coli in fluvial sediment 

during base-flow conditions, Coatesville study 

reach, 2003, West Branch Brandywine Creek, 

Chester County, Pennsylvania.
Relation of Bacteria to the Fluvial Environment in the West Branch Brandywine Creek and Its Tributaries 27

exact origin of these culverts is unknown; however, the construction of the culverts was consistent with other storm sewers 

in the region. E. coli concentrations within sediments collected 

at the outfall of these culverts measured over 37,000 and 

28,000 col/g of saturated sediment in 2003, respectively, and 

suggested these storm sewers may have been largely responsible for the elevated bacterial concentrations within the fluvial 

sediments near the outfalls. 

Observations of bacteria concentrations within this study, 

as compared to the description of the sampling location, showed 

that most sites with elevated bacteria concentrations were at, or 

near, the air/water interface at the edge of the active stream 

channel (this observation is made with due attention paid to the 

bias resulting from a sampling plan that largely targeted point 

sources along the streambanks). Other research, such as Whitman and Nevers (2003), also found higher concentrations of 

bacteria in this shallow, near-bank region than in deeper areas 

of the channel (most studies to date, however, have focused on 

lacustrine environments). Given that the elevated E. coli concentrations downstream of the wastewater-treatment facility 

also included substantial concentrations of E. coli within the 

fluvial sediments at the bottom of a deep pool (124,200 col/g of 

saturated sediment at site CB27), these data indicate the bacteria 

were deposited within this reach by way of remobilized sessilebacteria populations contained within transported sediments. 

Planktonic bacteria, as would likely originate from the wastewater-treatment facility and (or) waterfowl, would have had to 

selectively colonize sediments that data indicate do not reside in 

a preferred environment for this to occur; thereby reducing the 

likelihood that the wastewater-treatment facility and (or) waterfowl were the primary sources of this bacteria. Additional data 

are required to further substantiate these findings.

Sediment and Soil Filtration

As noted above, the area adjacent to the Coatesville study 

reach is largely utilized for urban and (or) industrial uses and is, 

consequently, mostly paved or covered with structures. Directly 

adjacent to the Coatesville study reach, most riparian zones 

were substantially reduced in size, and most wetlands were 

removed entirely, as a consequence of stream-channel relocation and (or) flood-plain encroachment by industry. The Wagontown study reach, although slightly altered, has remained 

largely forested with a far greater percentage of available floodplain, riparian zone, and wetlands (based on field observations). 

Given the differences between the two reaches, much more runoff from the region surrounding the Wagontown study reach is 

subject to infiltration and subsequent soil filtration. These field 

observations suggested that the lower bacteria levels within the 

water column of the Wagontown study reach (fig. 23) compared to the Coatesville study reach (fig. 24) were, at least in 

part, because of the relative lack of overland flows across paved 

areas and the effective filtration of runoff by adjacent wetlands 

and more substantial riparian zones. For example, the median 

concentration of E. coli within the water column of the Wagontown study reach, during base-flow sampling in 2003, was 

195 col/100 mL; within the water column of the Coatesville 

study reach, the median concentration of E.coli was 

960 col/100 mL, or almost five times higher, during the same 

period. Similarly, median enterococci concentrations were 

405 col/100 mL within the water column of the Wagontown 

study reach compared to 2,800 col/100 mL within the water column of the Coatesville study reach. 

Even though the Wagontown and Coatesville study 

reaches are separated by approximately 1 mi, the bacteria concentrations observed within the water column at the upstream 

end of the Coatesville study reach (above the city of Coatesville 

storm-sewer outfalls) were consistent with those observed 

along the Wagontown study reach (even though a tributary 

known as Rock Run enters the West Branch Brandywine Creek 

Figure 23. Escherichia coli and 

enterococci concentrations in the water 

column during base-flow conditions, 

Wagontown study reach, 2003, West 

Branch Brandywine Creek, Chester 

County, Pennsylvania.
28 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

between the two study reaches and commonly contains elevated 

bacteria concentrations). For example, the median E. coli concentration for the first 900 ft of the Coatesville study reach was 

300 col/100 mL during base flow in 2003. This concentration is 

generally consistent with the median E. coli concentration of 

195 col/100 mL observed during base flow in 2003 along the 

upstream Wagontown study reach. Similarly, the median 

enterococci concentration for the first 900 ft of the Coatesville 

study reach was 680 col/100 mL, which is also more consistent 

with the median enterococci concentration of 405 col/100 mL 

observed along the Wagontown study reach. These data indicate the reduced wetland and riparian areas within the Coatesville study reach are likely not as effective in the filtration of 

bacteria from runoff. Of course, the Coatesville study reach 

includes storm sewers that discharge directly into the creek, 

whereas storm sewers are not present in the Wagontown study 

reach. 

Other studies have shown the filtering capacity of wetlands and riparian areas and lend support to this interpretation 

of data from the Coatesville and Wagontown study reaches. 

Hench and others (2003) found that small constructed wetlands 

greatly reduced the amount of chemical and microbial contaminants that were introduced to a stream from domestic septic 

systems (single household) and that vegetated wetlands were 

more efficient than non-vegetated wetlands (gravel pack only). 

Also of note were the findings by Hench and others (2003) that 

the capacity of constructed wetlands to filter wastewater was 

observed to diminish over time, thus, allowing more bacteria to 

pass in subsequent years. Tufford and Marshall (2002) observed 

that the presence of stormwater retention ponds that concentrate 

and infiltrate stormwater attenuated fecal coliform bacteria levels and a large stormwater detention basin that concentrated and 

released stormwater through a small culvert with no infiltration 

did not. Further, Hunter and others (1992) compared soil matrix 

throughflow to overland runoff and found the soil matrix to be 

an efficient filter for bacteria. 

Bacterial data collected from fluvial sediments, within this 

study, could not with any certainty identify specific sites where 

sediment filtration was occurring and (or) failing along the 

West Branch Brandywine Creek because the sampling plan did 

not target this issue. Bacterial analyses along the Wagontown 

study reach (where most dominant wetlands were located) were 

switched from fecal coliform and fecal streptococcus bacteria to 

enterococcus bacteria in 2003; this change in bacterial analyses 

made comparisons between 2002 and 2003 data impossible. 

However, data analysis did identify a specific area along the 

Wagontown study reach at which future study may prove beneficial. During 2002, a small spring was sampled near the downstream end of the Wagontown study reach; because of the 

drought of 2002, this spring was one of the few springs 

observed to flow within the study area. This spring drains a 

small wetland area adjacent to a facility cited prior to 2002 for 

discharging raw sewage into the West Branch Brandywine 

Creek (D. Town, Chester County Health Department, oral commun., 2002). This spring had a generally high concentration of 

fecal coliform bacteria within the sediments near its source 

compared to other sites along the Wagontown study reach

(fig. 25). During 2003, much more water was present within 

this same wetland area, and water was observed to predominantly drain from the wetland area by way of numerous swales 

as well as from various springs. The largest of these flowing 

swales was sampled near the downstream end of the Wagontown study reach and showed a generally high concentration of 

E. coli within the fluvial sediments at the mouth of the swale. 

The spring sampled in 2002, however, did not have an elevated 

concentration of either E. coli or enterococci (fig. 26). 

Although climatic and runoff influences on this site likely affect 

the observed concentrations of various bacteria along this reach,

knowledge of the prior discharge of untreated sewage along 

with the observed elevated concentrations of bacteria adjacent 

to the wetland area indicate that some level of filtration is potentially occurring, or may have occurred along this reach; again, 

additional study is required to support this observation.

Figure 24. Escherichia coli and 

enterococci concentrations in the water 

column during base-flow conditions, 

Coatesville study reach, 2003, West 

Branch Brandywine Creek, Chester 

County, Pennsylvania.
Relation of Bacteria to the Fluvial Environment in the West Branch Brandywine Creek and Its Tributaries 29

Dams

Three dams currently are present within the Coatesville 

study reach on the West Branch Brandywine Creek (various 

other dams were historically present but have been removed). 

The first dam is an approximately 5-ft tall, low-head, run-ofthe-river dam at the upstream end of the Coatesville study reach

(fig. 27). This dam serves as the control structure for USGS 

streamflow-gaging station 01480500 (West Branch Brandywine Creek at Coatesville, Pa.), and the crest of this dam marks 

the beginning of the Coatesville study reach (station 0). The 

second dam is a slightly smaller, low-head, run-of-the-river 

dam approximately 3 ft high (fig. 28). The crest of the second 

dam is approximately 2,500 ft downstream from the first dam 

on the Coatesville study reach (station 2,500); this second dam 

is unique in that it lies completely within a channelized section 

of stream within the steel mill. Although not apparent in 

figure 28, access to the second dam was limited because of 

safety concerns and no samples were collected directly at the 

dam crest; however, samples collected at stations 2,167 and 

2,575 bracketed the dam. The final and largest dam is Dam #4 

at station 10,905 (fig. 29). This approximately 20-ft high, runof-the-river dam currently serves to divert water into the steel 

mill for industrial use and lies within a stream reach characterized by various soil, bedrock, and concrete banks.

While E. coli concentrations increased through the 

impoundment of Dam #4 and substantially decreased immediately downstream of the spillway in both 2002 and 2003 

(figs. 30 and 31), the smaller dam at station 2,500 had a lesser 

effect on E. coli concentrations. Two major differences 

between the structures may account for this variation in bacterial response. First, Dam #4 is much larger and, regardless of a 

large sediment wedge behind the dam, it slows and impounds 

water much more effectively than the dam at station 2,500. This 

greater capacity of Dam #4 to impede the flow of water is illustrated in figures 30 and 31 by the observed effect on turbidity as 

Figure 25. Fecal coliform bacteria 

and fecal streptococcus bacteria 

concentrations in fluvial sediment 

during base-flow conditions, 

Wagontown study reach, 2002, West 

Branch Brandywine Creek, Chester 

County, Pennsylvania.

Figure 26. Escherichia coli and 

enterococci concentrations in 

fluvial sediment during base-flow 

conditions, Wagontown study 

reach, 2003, West Branch 

Brandywine Creek, Chester County, 

Pennsylvania.
30 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

water flows through each impoundment area. Dam #4 shows a 

substantial effect on turbidity especially during the higher flows 

of 2003; the smaller dam at station 2,500 has virtually no effect 

on turbidity. Second, Dam #4 had an additional source of nutrients originating from the Coatesville region. As noted above, 

introduction of these additional nutrients along with a longer 

residence time (slower water) likely increased the capacity of 

algae to proliferate within the impoundment area of the dam and 

potentially caused higher bacterial concentrations because of 

bacterial regrowth. 

The elevated concentrations of E. coli observed within the 

impoundment of Dam #4 decreased dramatically downstream 

from the spillway of Dam #4 in 2002 and 2003 (figs. 30 

and 31). This rapid decrease in E. coli concentrations within the 

water column, as well as the absence of bacteria within the fluvial sediments directly downstream, indicated that E. coli were 

removed at, or immediately adjacent to, the spillway by an 

undefined process. The smaller dam, upstream at station 2,500, 

did not have this population decrease and had little effect on the 

E. coli concentration. The same pattern of population decrease 

was not as readily apparent for enterococci because populations 

of these bacteria decreased within the impoundment area of 

Dam #4 before they reached the spillway (fig. 32); therefore, it 

was unclear if enterococci populations were affected by processes similar to E. coli once they reached the dam crest. 

Numerous other studies, such as Town (2001), have documented similar decreases in bacterial concentrations downstream of dams and (or) other instream structures; however, 

even at the larger Dam #4, insufficient energy was likely available to account for this population decrease by mechanical processes (rupture of the cell walls and subsequent death of the 

bacteria) (S. Haack, U.S. Geological Survey, written commun., 

2004). Therefore, although this study does point out that relatively larger dams (as compared to small low-head dams), or 

other instream structures, can, and do, affect bacteria concentrations within the fluvial environment, the actual process remains 

unclear and requires additional study

Figure 27. Dam at station 0 on Coatesville study reach, West 

Branch Brandywine Creek, Chester County, Pennsylvania. 

Flow is from right to left. (Photograph by P.J. Cinotto, USGS)

Figure 28. Dam at station 2,500 on Coatesville study reach, 

West Branch Brandywine Creek, Chester County, 

Pennsylvania. View looking upstream. (Photograph by P.J. 

Cinotto, USGS)

Figure 29. Dam at station 10,905 (Dam #4) on Coatesville study 

reach, West Branch Brandywine Creek, Chester County, 

Pennsylvania. Flow is from right to left. (Photograph by P.J. 

Cinotto, USGS)
Relation of Bacteria to the Fluvial Environment in the West Branch Brandywine Creek and Its Tributaries 31

Figure 30. Escherichia coli and turbidity in the 

water column during base-flow conditions, 

Coatesville study reach, 2002, West Branch 

Brandywine Creek, Chester County, 

Pennsylvania.

Figure 31. Escherichia coli and turbidity in 

the water column during base-flow 

conditions, Coatesville study reach, 2003, 

West Branch Brandywine Creek, Chester 

County, Pennsylvania.

Figure 32. Enterococci and turbidity in the 

water column during base-flow conditions, 

Coatesville study reach, 2003, West Branch 

Brandywine Creek, Chester County, 

Pennsylvania.
32 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

Turbidity

Turbidity, or the suspended matter in the water column, 

generally is derived from five major sources in the study area of 

the West Branch Brandywine Creek: erosion of streambanks; 

erosion of the streambed; top soil and sediments from overland 

flows; biological sources, such as algae and plankton; and (or) 

industrial discharges. Turbidity is quantified by measuring the 

scattering of light as it passes through the suspended particles 

and water. The units of measure of turbidity used in this study 

were nephelometric turbidity units, or NTU; loosely translated, 

nephelometric means “the measure of cloudiness.” Turbidity 

measurements do not, therefore, differentiate between one 

source or type of suspended material as opposed to any other. 

Any material that scatters light within the water column is measured as turbidity. 

Bacteria are not found uniformly throughout a stream 

reach with complex land usages and (or) widely varying chemical gradients such as the West Branch Brandywine Creek. 

Therefore, the general relation of turbidity to bacteria will be 

inconsistent because sediments containing various concentrations of bacteria are mobilized by water originating from many 

sources. For example, isolated thunderstorms are common in 

the West Branch Brandywine Creek Basin throughout the summer months. If the storm is in the upper reaches of the basin, turbidity will be derived primarily from the top soil of agricultural 

areas; if the storm is over the city of Coatesville, turbidity will 

be derived from sediment originating from, and adjacent to, 

stormwater outfalls. Each of these storms could, therefore, have 

a much different turbidity-to-bacteria relation because the sediment sources vary. As an added consideration, bacteria can and 

do die off and (or) attach to surfaces as they are transported 

downstream; this die off and (or) attachment also, potentially, 

affects the relation between bacteria and turbidity at any given 

point on the stream, especially during lower flows. 

The variable relation between E. coli and turbidity 

observed on the West Branch Brandywine Creek is shown in 

figures 33 through 36. The coefficient of determination, R2, is a 

measure of variability accounted for by the regression relations 

in the observed indicator bacteria concentration compared to 

turbidity. The closer the R2 value is to 1.00, the less variability 

is present in the data. If an R2 value indicates the possibility of 

a valid statistical trend, a p-value must be calculated to validate 

the relation. The p-value measures the “believability” of the 

level of significance of the statistical test. If the p-value is less 

than 0.05, the test is considered significant and the trend, as represented by the regression line, can be assumed to be real. Further statistical analysis can be conducted if one or more data 

points appear to have undue effect or “leverage” on a regression 

relation. The Cook’s distance statistic is a measure of this effect. 

For most data sets, data point with Cook’s distance values 

above approximately 2 may be considered to have a significant 

leverage effect on the regression.

The relations of E. coli to turbidity under base-flow conditions in 2002 and 2003 on the Coatesville study reach are shown 

in figures 33 and 34. Regression analysis of these base-flow 

Figure 33. Relation between base-flow turbidity and Escherichia 

coli bacteria in the water column within Coatesville study reach, 

2002, West Branch Brandywine Creek, Chester County, 

Pennsylvania.

Figure 34. Relation between base-flow turbidity and

Escherichia coli bacteria in the water column within 

Coatesville study reach, 2003, West Branch Brandywine 

Creek, Chester County, Pennsylvania.
Relation of Bacteria to the Fluvial Environment in the West Branch Brandywine Creek and Its Tributaries 33

data did not yield a statistically valid relation with R2 values of 

0.13 and 0.02, respectively. The relations of E. coli bacteria to 

turbidity under stormflow conditions in 2002 and 2003 on the 

Coatesville study reach are shown in figures 35 and 36. Regression analysis of data from a storm event in 2003 on the Coatesville study reach presented a similarly poor statistical relation 

between E.coli and turbidity, with an R2 of 0.21. However, 

regression analysis of data from a storm event in 2002 presented 

a stronger statistical relation between E. coli and turbidity, with 

an R2 of 0.94 and a p-value of 0.00. These data indicated that, 

during stormflow, the sources of the turbidity-causing sediments and the bacterial concentrations within those sediments 

were likely different. It should be noted, however, that whereas 

the R2 and p-value indicated a strong relation between E. coli 

and turbidity within the 2002 stormflow data set, analysis of the 

Cook’s Distance statistic yields a value of >8 for a single data 

point at the upper end of the regression line (9,000 col/mL of 

E. coli and 17.1 NTU) (fig. 35). This data point had too strong 

of an effect on the overall data set to make any legitimate conclusions about the overall relation between E. coli and turbidity 

for this sampling event. In summary, the West Branch Brandywine Creek had too much variation to establish a strong correlation between bacteria, such as E. coli, and turbidity for any 

one hydrologic event. 

Figure 35. Relation between stormflow turbidity 

and Escherichia coli bacteria in the water 

column within Coatesville study reach, 2002, 

West Branch Brandywine Creek, Chester 

County, Pennsylvania.

Figure 36. Relation between stormflow 

turbidity and Escherichia coli bacteria in the 

water column within Coatesville study reach, 

2003, West Branch Brandywine Creek, 

Chester County, Pennsylvania.
34 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

A larger data set that included all E. coli and turbidity data 

collected from the Coatesville and Wagontown study reaches 

during base flow and stormflow was analyzed (n = 95). The 

relation between turbidity and E. coli strengthened slightly as 

the effects of individual outliers were reduced. Regression analysis of this larger data set yielded a slightly stronger, but still 

weak, statistical relation between E.coli bacteria and turbidity 

with an R2 value of 0.67 and a p-value of 0.00 (fig. 37). This 

regression analysis of the larger data set generally indicated that 

higher turbidity levels usually can indicate higher bacterial concentrations, however, no absolute determination of bacteria 

concentration based on turbidity would be feasible on this reach 

of stream. Simply stated, suspended sediments commonly contained E.coli, but the relation was too sporadic on the West 

Branch Brandywine Creek to use turbidity as a feasible surrogate for estimated bacteria concentrations.

Questions were present as to whether the turbidity-to-bacteria relation would strengthen if data were collected from a single point along the stream rather than from multiple points 

along the study reach as discussed above. Therefore, in 2003, an 

autosampler and an Analyte turbidity probe were installed at the 

downstream end of the Coatesville study reach (in USGS 

streamflow-gaging station 01480617, West Branch Brandywine Creek at Modena, Pa.). The Analyte turbidity probe was 

calibrated and checked according to manufacturer’s specifications prior to sampling and initial data were confirmed by comparing measurements from the Analyte probe to turbidity measurements from a YSI water-quality sonde. This autosampler 

was programed to collect samples every 30 minutes from a 

fixed location while USGS personnel also were concurrently 

collecting the spatial storm samples discussed above. Eleven 

samples were subsequently collected by the autosampler 

(appendix 5) and a regression analysis was performed to test the 

strength of the relation of turbidity to bacteria at this site 

(fig. 38). This test yielded an equally poor statistical relation 

with an R2 of 0.13 and a p-value of 0.27. 

The wide variety of environmental factors within the West 

Branch Brandywine Creek, such as large industrial inputs, 

localized areas of impervious cover, storm-sewer systems, 

dams, reduction of riparian zones, and (or) other factors, all 

adversely affected the relation between the bacteria and turbidity. Large data sets were required to obtain any level of statistical significance and outliers were common, making utilization 

of turbidity as a surrogate for bacterial analysis impractical 

throughout the study area. It should be noted that other research 

by Rasmussen and Ziegler (2003) showed that bacteria and turbidity can yield a moderately strong and consistent relation. 

However, environmental conditions, primarily the utilization of 

much larger drainage areas, were different in that study. The use 

of larger watersheds in the regression analysis by Rasmussen 

and Ziegler (six sites ranging from 759 to 59,756 mi2) likely 

reduced the effect of any single environmental factor on the 

overall regression analyses. The largest drainage area in this 

study was at the downstream end of the Coatesville study reach 

and drained only 55 mi2; therefore, the statistical relation 

between bacteria and turbidity is much more sensitive to minor 

environmental effects. For example, the input from a single 

storm-sewer outfall and (or) a small eroding bank generally 

contributed a much larger percentage of the overall volume of 

bacteria and (or) suspended sediment to the smaller Coatesville 

study reach than to the larger river utilized by Rasmussen and 

Zeigler (2003). 

Figure 37. Relation between turbidity and Escherichia 

coli bacteria in the water column within Coatesville 

and Wagontown study reaches, 2002-2003, West 

Branch Brandywine Creek, Chester County, 

Pennsylvania.
Relation of Bacteria to the Fluvial Environment in the West Branch Brandywine Creek and Its Tributaries 35

Potential Sources of Bacteria on Selected Reaches of 

the West Branch Brandywine Creek

Sediment

The concentrations of sessile bacteria stored within stream 

sediments can be 3-4 orders of magnitude higher than that contained within the water column. These bacteria are commonly 

subject to remobilization during periods of above-average 

streamflows and (or) other erosional events. As a consequence 

of the remobilization of this stored bacteria supply, elevated 

concentrations of bacteria observed within the water column 

during storm events are likely because of remobilized sessile 

bacteria and not a direct sewage source, such as the discharge of 

raw sewage. Reducing streambank and streambed erosion will 

reduce the available sediment supply and, subsequently, reduce 

the bacteria remobilized within the stream during storm events. 

Of note is that wetter years generally can have higher concentrations of bacteria within fluvial sediments and other environments throughout the watershed than dry years.

Storm Sewers

Storm sewers discharging directly into a stream, without proper 

stormwater management, concentrate bacteria and other contaminants into a single point and commonly bypass the natural 

filters created by wetlands and riparian zones. As a result, high 

concentrations of bacteria generally are observed within the 

sediments adjacent to, and within, the outfall of storm sewers 

that drain impervious areas. These impervious areas do not have 

to be urban or even residential because the source of the bacteria 

may be waterfowl, rodents, bats, dogs, deer, and other animals; 

however, it is the combination of concentration and removal of 

natural filtering mechanisms that causes this geographic source. 

Simply adding detention basins that allow for infiltration of 

runoff has been shown to decrease bacterial concentrations as a 

“filter” has been placed back in-line. However, human-made 

structures, such as artificial wetlands, and even over-taxed natural wetlands, require on-going maintenance because bacteria, 

and other constituents, have been shown to overload and saturate the sediments, thereby reducing the filtering capability of 

the structures over time.

Figure 38. Relation between stormflow turbidity 

and Escherichia coli bacteria at U.S. Geological 

Survey streamflow-gaging station 01480617, 

West Branch Brandywine Creek, Chester 

County, Pennsylvania.
36 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

Bacterial Regrowth

Data indicate that increased E. coli concentrations 

observed within the impoundment area of a dam may be the 

result of a symbiotic relation with aquatic growth and may not

be the result of the direct input of fecal contamination to the 

impoundment area. This potential, natural population increase 

is termed bacterial regrowth. The same potential regrowth 

effect was not observed in the enterococci population within the 

same impoundment area, and enterococci populations were 

shown to actually decrease. These data indicate that different 

types of bacteria may have different responses to environmental 

variations within impoundment areas and (or) other regions. 

Bacteria have previously been shown to potentially exhibit 

regrowth in the presence of certain types of algae (Chlorella and 

(or) Cladophora glomerata) by McFeters and others (1978) and 

Whitman and others (2003). This regrowth, if feasible, presents 

a natural source of bacteria often utilized as fecal indicators. 

This finding would potentially limit the use of certain types of 

bacteria as an indicator of fecal contamination within specific 

environments. The impoundment areas of lakes and reservoirs, 

as well as fluvial environments, that may have algal blooms are 

potentially most affected by the false indications of fecal contamination caused by this process. 

Protocols for Assessment of Fecal Contamination Using Sandbag Samplers and 

Optical-Brightener Monitoring

Description of Method and Equipment

As noted earlier, approximately 99 percent of bacteria in 

nature are present as attached, or sessile, bacteria (Potera, 

1998). This sessile bacteria population can, thus, be more representative of conditions within the fluvial environment than 

free-floating, or planktonic, bacteria; however, the great variability that occurs within natural sediments (variable particle 

sizes, organic content, mineralogy, and (or) other factors) commonly can reduce the ability to accurately interpret data collected from them. Research conducted by Nix and Merry (1990) 

suggests a method whereby much of the variability associated 

with natural sediments may be reduced and the larger sessile 

bacteria population may be assessed. The Nix and Merry 

method initially called for 300 g of sterile construction-grade 

sand to be enclosed in a nylon bag and suspended in the stream 

for approximately 1 week. During this time, bacteria would 

attach to the sand and, in effect, the samplers would take a 1-

week “swab” of the stream. For this study, however, a modified 

version of the Nix and Merry method was implemented. As 

noted above, various bacteria appear to preferentially attach and 

persist within sediment based, partly, on the particle distribution or grain size of that sediment; therefore, the Nix and Merry 

method was modified to specifically target E. coli bacteria by 

sieving construction-grade, quartzose sand to a particle size 

conducive for the persistence of E. coli, which in this case was 

0.5 to 1.0 mm. This size range, however, was based on a small 

preliminary data set, and the current, more comprehensive, data 

set, as noted above, now indicates a slightly finer particle distribution should likely have been utilized (from 0.25 to 0.5 mm) 

for this study. 

Results From Trial Installation of Sandbag and OpticalBrightener Samplers

Fifteen of the modified sandbag samplers (fig. 39) were 

installed at 15 different sites along the Coatesville study reach 

(no samplers were installed along the Wagontown study reach 

because of a limitation in the number of samples that could be 

processed by the laboratory). Regardless of any potential error 

resulting from too coarse of sediment within the bags, the sandbag samplers generally worked as anticipated (all data collected 

are presented in appendix 4); analysis of these sandbags found 

that E.coli concentrations generally were similar in both the 

sandbags and natural sediments (fig. 40), and enterococci concentrations generally were lower in the sandbags than in natural 

sediments (fig. 41). The poor results for enterococci were likely 

because the particle distribution within the sandbags was too 

coarse and did not provide an environment that enterococci prefer to colonize; however, further study is required to confirm 

this. As in all bacterial analyses, outliers occurred and results at 

lower concentrations were generally noisy (see Limitations of 

Samplers section). Refinements to the composition of the sandbag samplers are also suggested on the basis of the research previously cited, as well as research by Rogers (2002). These 

refinements generally involve the composition of the sand filling the nylon bag; this refinement could include one or more of 

the following steps: adding iron to the sand (allows iron-reducing bacteria to potentially condition the sand substrate and creFigure 39. Sandbag and optical-brightener samplers (pick for 

scale). (Photograph by P.J. Cinotto, USGS)
Protocols for Assessment of Fecal Contamination Using Sandbag Samplers and Optical-Brightener Monitoring 37

Figure 40. Escherichia coli concentrations in sandbags and natural fluvial sediment, Coatesville study reach, 

2003, West Branch Brandywine Creek, Chester County, Pennsylvania.

Figure 41. Enterococci concentrations in sandbags and natural fluvial sediment, Coatesville study reach, 2003, 

West Branch Brandywine Creek, Chester County, Pennsylvania.
38 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

ate a better environment for attachment of fecal-indicator bacteria), and (or) adding potassium (as per Rogers, 2002, bacteria 

preferentially attach to potassium rich minerals, such as potassium feldspars, in nutrient-poor environments). It also should 

be noted that sandbags are possibly not the best solution for all 

sites and (or) all climatic conditions. During severe drought 

conditions, for example, bacteria levels generally are lower in 

all environments and many outfalls that may be tested could be 

dry. In these cases, samples from wet, natural sediments may 

prove to be a better solution for the detection of potential 

sources of bacterial contamination. Also, given that bacteria are 

able to preferentially colonize sediments, stream reaches having 

extreme fluctuations in water quality may, or may not, provide 

a suitable location for sandbag placement. Protocols and guidance for each method are described in the next section. 

In addition to sandbag samplers, additional samplers were 

added to detect optical brighteners in the water column (R.L. 

Whitman, U.S. Geological Survey, oral commun., 2003); an 

example of an optical-brightener sampler is shown in figure 39 

along with a sandbag bacteria sampler. Optical brighteners are 

additives used in common household detergents; optical brighteners are common in wastewater and are present in most sewage. Therefore, if optical brighteners are detected, along with 

elevated fecal-indicator bacteria concentrations, a human 

source can be associated with the bacterial contamination. The 

basic principle of the optical-brightener technique is that optical 

brighteners will fluoresce, or glow brightly, when exposed to 

long-wavelength (356 nm) ultraviolet (UV) light. Application 

of the method calls for perforated, vinyl-coated bags containing 

sterile, analytical-quality cotton (balls, pads, or bulk) to be 

installed along with each sandbag. The cotton used for testing 

must be unwashed, so no optical brighteners will have been previously added and, therefore, under UV light, these unwashed 

cotton balls will appear black (they will not glow). If the cotton 

comes into contact with, and subsequently absorbs, water containing high concentrations of optical brighteners, the cotton 

will fluoresce (glow bright blue) when exposed to long-wavelength UV light. 

Results from this study found only two positive opticalbrightener tests; both positive samplers were at the outfalls of 

wastewater-treatment facilities. Because of treatment by the 

respective facilities at these two sites, however, the concentrations of E. coli during base flow were only <1 and 

80 col/100 mL. None of the storm-sewer outfalls returned a 

positive result for optical brighteners even though the chemical 

analysis noted above indicated some sewage was present. These 

results highlight that optical brighteners are present in most 

sewage (even treated effluent), but the concentration of optical 

brighteners detectable by this method is likely high and could 

not be quantified by this study. 

The benefit of the optical-brightener method is in its simplicity and cost-effectiveness; however, the method has some 

limitations. This method can only be expected to produce a 

“positive” or “negative” result and then, as noted above, only 

when the concentrations of optical brighteners are high in the 

water column. Therefore, data from these optical-brightener 

samplers must be interpreted as either “definitely present” or 

“possibly absent.” To assist with interpretation, a set of standards are made from common liquid laundry detergent. These 

standards will not provide a measure of concentration but will 

serve to greatly improve the ability of the analyst to detect a 

“positive” result (these bags can become fouled in the environment). Optical brighteners also degrade in bright sunlight; the 

use of vinyl-coated bags protects the cotton and optical brighteners from direct sunlight while still providing adequate contact 

with streamflow. Protocols and guidance for this method are 

described below.

Application of Method for Assessment of Escherichia 

Coli and (or) Enterococcus Bacteria

The following instructions detail the construction, installation, and analysis of bacteria and optical-brightener samplers 

along with a comprehensive list of materials required. The construction and use of these samplers is based on principles determined from this and previous studies. All methods and techniques utilized were developed within the last 15 years; 

however, these methods have not been widely utilized to date. 

Potential areas where improvements might be beneficial have 

been noted below as applicable; however, additional data must 

be collected prior to any modifications. The user of these methods should adhere to all basic field and laboratory methods and 

techniques to assure quality control and quality assurance as 

defined in Clesceri and others (1998). 

Construction of Samplers

The sandbag and optical-brightener samplers may be constructed utilizing materials from the equipment list provided 

below. Care should be taken during construction of the samplers 

because consistency is important in this process. During construction, care also should be taken to prevent bacterial contamination of the materials. The work area should be sterilized 

using a dilute bleach solution and rinsed thoroughly, rubber 

gloves should be worn, and all sterilized materials should be 

stored in sterile plastic bags. 

Complete construction of the sandbag samplers as follows:

1. Dry the contents of a 40-lb bag of general-purpose construction sand by placing smaller portions in a drying 

oven, heating it over a hot plate, or simply spreading it in 

the sun. This process may take a full day; however, this 

process will save much time during the sieving, which 

will remove all but a small fraction of the original volume.

2. Sieve the dry sand and separate the particle range 

appropriate for the targeted bacteria (a size range of 0.25 

- 0.5 mm for E. coli and 0.125 - 0.25 mm for enterococci 

was shown to be effective, however, this data set is 

statistically weak, relies on observations alone, and is 

specific to this data set). Caution: Note that the 

enterococcus data set presented above (fig. 41) is noisy; 
Protocols for Assessment of Fecal Contamination Using Sandbag Samplers and Optical-Brightener Monitoring 39

this likely indicates that the 0.125 - 0.25 mm size range 

will require refinement as future data are added. Refer to 

the detailed description above for more information on 

this topic.

3. Weigh 300 g aliquots of the applicable sieved sand in 

standard weigh boats and steam-sterilize in an autoclave. 

Note: The sand will be wet subsequent to steamsterilization, which is why the aliquots must be preweighed and sterilized individually. 

4. Pour the sterile sand into a nylon stocking and knot 

BOTH ends (the factory-sewn seam may separate under 

load in the field). The nylon stockings are not sterilized at 

this stage, however, they are assumed to be sterile from 

the manufacturer. Additional steam sterilization, as noted 

below, can address this concern, if required. 

5. Place the sandbag in a sterile container and set aside (a 

sterile bucket with a lid works well for bulk 

applications). Additional steam sterilization usually is 

not required; however, if sterilization of the completed 

bag is desired, use a lower temperature to prevent 

melting or weakening the nylon.

Complete construction of the optical-brightener samplers 

as follows:

1. Obtain laboratory-grade cotton (balls, pads, or bulk) and 

check with the 356-nm UV light to assure that the cotton 

does not contain optical brighteners. The cotton should 

remain dark if unwashed and will fluoresce (glow 

brightly) if it has been washed. The occasional small piece 

of cotton that fluoresces generally is unavoidable; however, the vast majority of the cotton should appear black 

under the UV light. High-quality cotton from scientificsupply companies generally works better than that purchased from the local drug store. 

2. Obtain Hubco Protexo sand-sample bags or an equivalent. 

These bags are palm-sized, vinyl-coated, light-canvas 

bags used for the collection of drill cuttings. Most 

environmental supply companies will carry these bags or 

an equivalent. Use a standard hole punch and evenly 

perforate the bags approximately 20 times (all the way 

through the bag, so there are at least 20 holes per side). 

These holes should be evenly spaced to allow water to 

flow through while the cotton is held inside.

3. Place approximately five cotton balls in each bag (or a 

piece about the size of two golf balls if using pad- or 

bulk-type cotton).

4. Tie the bag securely and set aside (these bags do not have 

to be sterilized).

Immediately prior to installation in the field, securely tie 

the sandbag to the end of a length of masonry cord. Place a 

small loop in the cord approximately 5 in. above the sandbag 

and tie the optical-brightener sampler to this loop; the weight of 

the sandbag will help keep the optical-brightener sampler submerged. An optional mesh bag may be secured over the entire 

assembly and secured to the masonry cord. The mesh bags generally serve to protect the samplers and (or) possibly contain a 

sampler if it becomes detached from the masonry cord. The 

masonry cord can then be affixed to the metal anchor ring, as 

described in the installation of samplers section below, and cut 

to length as dictated by the site conditions.

Installation of Samplers

1. Locate a position whereby the sampler will hang into a 

slightly shaded part of the stream with steady flow, but 

with slow enough velocities as not to destroy the sandbag 

(the sandbag should easily remain submerged and should 

not “skip” on, or near, the surface). Even though sandbags 

are tough, the sand can be pushed through the nylon mesh 

in fast flows. If sand is pushed through the mesh, the 

sample will not be valid because bacteria will not likely be 

able to attach to the sand in these conditions.

2. If possible, measure pH, dissolved oxygen, temperature, 

and specific conductance at the site to determine if 

extreme values are present relative to the local 

conditions. If measurements vary appreciably, bacteria 

may not attach to sediments at the site.

3. After the attachment location is determined, an 

approximately 4-in. piece of galvanized plumbers strap 

should be cut, wrapped around the steel ring, and 

fastened to the culvert pipe, bridge, tree, or other object 

with a masonry anchor or ring-shank nail (fig. 42). This 

permanent ring will allow additional samplers to be 

placed in the same location during subsequent sampling 

events.

4. Tie the masonry cord holding the samplers securely to the 

ring with sufficient cord length to allow the samplers to 

rest on the bottom, or in no greater than about 2 ft of 

Figure 42. Mounting hardware for sandbag and opticalbrightener samplers. (Photograph by P.J. Cinotto, USGS)
40 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

water, without so much slack that they can be washed out 

of the flow. If the samplers are found dry, the sample will 

not be valid because the sand must remain moist. 

5. Samplers can be installed in streams, at the mouth of 

culverts, or in springs provided that water is present and 

flowing. In deep water (greater than 2 ft deep), the 

samplers should be suspended near the surface. 

6. If no flow is present, the sandbag and optical-brightener 

samplers will not be effective. In the case of no, or low, 

streamflow, bacteria samples should be collected from 

moist, natural sediment (primarily sandy sediments, if 

available) at the location in question. These bacteria 

samples may be analyzed along with the sandbag 

samplers as described below.

7. Samplers can be installed during any flow regime (lowflow periods or the occasional high flows during or just 

after a storm event); however, data collected over 

extended periods of base flow are likely to be 

substantially easier to interpret. Bacterial resolution 

during base-flow periods will likely be better because 

background bacteria levels generally will not be elevated 

(potentially masking smaller bacterial sources). Bacteria 

within the water column, during base-flow periods, are 

also more likely to be planktonic, meaning they are more 

likely to have originated from leaks and other inputs 

instead of being remobilized from the stream channel. 

Optical-brightener sampling also will be more effective 

during dry periods because wastewater will be more 

concentrated and, thus, more likely to be detected.

8. After installation, the samplers should be left in the 

stream for approximately 1 week. This time frame, as 

used in this study, was arbitrary; however, the time 

allowed was considered to be of sufficient duration to 

allow bacteria to attach in sufficient numbers to be 

representative of environmental conditions. Even though 

the residence time in the stream may, ultimately, be 

refined on the basis of data from future studies, it should 

be noted that consistency is important in relating data 

collected at one site to another. For example, if a study 

begins with a sampling duration of 1 week, that period 

should be maintained throughout the study. 

9. Upon removal from the stream, sandbag and opticalbrightener samplers should be placed in a sterile 

container, placed on ice, and transported to the laboratory 

following the same guidelines as established for samples 

collected from the water column.

Analysis

Simplified methods of analysis for the determination of 

bacteria concentrations in sediment and optical brighteners 

have been created for use in this study and are presented below. 

Analytical results for bacteria are reported in “colonies per 

gram of saturated sediment,” because moisture content of sediments are not determined by this method in the laboratory. If 

laboratory capabilities are sufficient, the following method may 

be amended to adjust for actual dry-sediment volume and, thus, 

improve the precision of the overall analysis. However, given 

the inherent variability present in all bacterial analyses, the 

overall accuracy of the bacteria analysis will not likely be 

greatly improved by the implementation of this additional 

method.

Natural Sediment and Sandbag Samplers

1. At the laboratory, the sediment samples should be carefully set aside for 30 minutes and allowed to settle. 

2. At the end of this 30-minute period, any remaining 

residual water should be gently decanted and discarded.

3. Carefully weigh out approximately 20 g of the wet 

sediment avoiding large pieces of gravel and organic 

debris in the sample if analyzing natural sediment 

samples.

4. Add the sediment to a 100-mL volumetric flask or other 

similar, sterile, container.

5. Dilute to the 100-ml mark with a sterile buffer solution. 

Buffers prevent osmotic shock and encourage the 

appropriate electrostatic environment to dislodge bacteria 

from sediment particles (S. Haack, U.S. Geological 

Survey, written commun. 2004). 

6. Shake the flask for 45 seconds. Ideally, a laboratory wristaction shaker should be utilized, but use of this shaker is 

generally impractical for smaller laboratories because of 

cost.

7. Allow the sample to settle for 30 to 45 seconds. In this 

short time period, the bacteria will remain in suspension 

while most coarse sediments will settle out. 

8. Analyze this supernatant by way of standard membrane 

filtration techniques that are applicable for the type of 

bacteria being sought. It should be noted that natural 

sediment samples can contain large percentages of silts 

and clays. These fine sediments generally do not settle 

easily, can plug filters, alter the shape of bacterial 

colonies on the plates, and generally can make counting 

bacterial colonies more difficult. Using sieved sand and 

the sandbag samplers greatly reduces this problem. 

9. Apply a dilution factor to the final count to account for 

the creation of the initial solution. Two simplified 

methods are presented here for use in basic laboratories 

that are common at most municipal levels; one for natural 

sediment samples and one for sandbag samples. Note that 

this method for determining a dilution factor was 

developed based on specific laboratory limitations within 

this study; an acceptable dilution factor may be 

determined for each individual sample by weight alone. 

Weight of sample (g) A/1.65 = B (mL)
Protocols for Assessment of Fecal Contamination Using Sandbag Samplers and Optical-Brightener Monitoring 41

100 mL (total volume) - B = C (g)

A + C = D = total weight (g)

A / D = E = weight of the sample divided by the total weight

1 / E = F = final dilution factor

SANDBAG SAMPLE DILUTION-FACTOR METHOD:

Determine the submerged specific weight of the material used 

in the sandbag as follows, if the material is not quartzose sand. 

If quartzose sand is used, use a submerged specific weight (γs) 

of 1.65 and skip this step; again, the dilution factor may be 

determined for each individual sample by weight:

1. Fill a 500-L beaker three-quarters full with the same sand 

used to fill the sandbag samplers.

2. Fill beaker with de-ionized water and drain by decanting 

the water (to saturate the sand).

3. Using a 100-mL graduated cylinder, tare and weigh out 

approximately 20 g of the saturated sand and note the 

weight (a).

4. Fill to the 100-mL mark with de-ionized water and note 

the final weight in grams (b).

5. (b - a) = weight of deionized water added (c).

6. 100 - (c) = weight of the water displaced by the saturated 

sediment in grams (d); note that 1 mL of deionized water 

weighs 1 g.

7. (a) / (d) = submerged specific weight (γs) of sand used in 

sampler.

8. Carefully repeat this process 10-15 times and take the 

average value. 

9. Use this computed submerged specific weight (γs) to 

determine the dilution factor.

Weight of sample (g) A/ γs = B (mL)

100 mL (total volume) - B = C (g)

A + C = D = total weight (g)

A / D = E = weight of the sample divided by the total weight

1 / E = F = final dilution factor

Optical-Brightener Samplers

1. Prior to analysis of cotton from the optical-brightener samplers, the analyst will likely observe that the cotton is very 

fouled by sediment, algae, iron, and (or) other staining 

agents. These stains can make a definitive “positive” or 

“negative” determination quite difficult. To increase the 

accuracy of interpretation and prevent bias, a simple set of 

four standards is created and utilized as a comparative 

scale. Most liquid laundry detergents will work for the 

creation of these standards (for this study, liquid “Tide 

with bleach alternative” was used). For the standards, 

create the following three dilutions of the liquid laundry 

detergent and apply the solution to clean cotton (the same 

cotton as used in the samplers) in individual 50-mL beakers or similar glassware; a blank standard also is 

included and is composed of a plain piece of cotton wetted 

with de-ionized water. 

1. 0 (Plain cotton sample)

2. 1:10,000

3. 1:1,000

4. 1:100

2. Disassemble the optical-brightener sample bags and 

carefully place the samples in individual glass beakers. 

Using forceps, gently spread the cotton to expose the 

cleaner inside portions of the cotton (the inside of the 

cotton will have also absorbed any optical brighteners). 

3. In a darkened room, illuminate the still-wet sample and 

standards with long-wave UV light (356 nm).

4. If the sample glows brighter than the lowest standard, the 

sample is “positive” and an anthropogenic input of 

wastewater is suspected. 

5. If the sample does not appear brighter than the lowest 

standard, the sample is “negative” and an anthropogenic 

input of wastewater is not present in concentrations high 

enough to detect; wastewater may still be present. 

6. As a note of caution, the ability to create a set of standards 

would suggest that optical-brightener concentration also 

could be estimated; however, any attempt to do this 

estimation should be approached with great caution 

because the basic analysis is designed to be qualitative 

and not quantitative. Detailed laboratory analysis of the 

chemical composition of the water should be used for 

analysis of any wastewater concentrations.

Equipment List for Construction and Installation of 

Samplers

1. Quartzose (mostly quartz) construction sand 

(available at most home centers)

2. Oven or hot plate to dry sand (sand often comes 

wet and does not sieve easily)

3. Miscellaneous glassware

4. Sieves as defined by data from this study (U.S.A. 

Standard testing sieves)

a. Catch pan (to hold in sand so sieves can be 

shaken)

b. 0.125 mm (lower end of enterococci range)

c. 0.25 mm (lower end of E. coli range and 

upper end of enterococci range)
42 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

d. 0.5 mm (upper end of E. coli range)

e. 2.0 mm (to break up clumps and protect finer 

sieves)

f. Lid (to hold in sand so sieves can be shaken)

5. Scale (to weigh out portions and fill bags)

6. Autoclave (to steam-sterilize sand and other 

equipment)

7. Nylon bags (nylon stockings were used for this 

study)

8. Hubco Protexo sand-sample bags or equivalent 

(to hold cotton)

9. Unwashed cotton balls, cotton pads, or bulk 

cotton

10. Hole punch (to perforate Hubco Protexo bags)

11. Masonry cord (or other small, strong cord to 

anchor samplers)

12. Heavy nylon-mesh sample bags (optional; available from most scientific supply companies)

13. 1- to 2-in. chrome-plated steel rings to tie samplers to (the smooth rings will not wear through 

the cord)

14. Plumber’s strap (for affixing rings to culverts, 

trees, or other objects)

15. 1/4-in. concrete anchors (concrete anchors will 

securely fasted samplers to concrete and (or) 

stone objects)

16. Cordless drill with 1/4-in. masonry drill bit (for 

concrete anchors)

17. Ring-shank nails (ring-shank nails will securely 

fasten samplers to wooden objects)

Limitations of Samplers

The initial design of sandbag and optical-brightener samplers was based on the work of Nix and Merry (1990) and 

numerous discussions with others. Techniques presented within 

these protocols were then, subsequently, refined on the basis of 

the limited data collected during this study. Because of the preliminary nature of these techniques, revisions to the design and 

implementation of the samplers is anticipated during future use. 

As noted above, revisions to the particle size within the sandbags, the composition of the sand filling, and sampler placement may all require alteration in the future. The analyst should 

maintain careful notes on composition of the sandbags, sandbag 

placement in the stream, and field or laboratory conditions, to 

allow for these future modifications. Sandbag bacteria data 

were also noisy at lower bacteria concentrations. These variable 

data at lower concentrations illustrates the need for the determination of statistical limits below which the concentration of bacteria cannot be measured or reported accurately; these limits are 

termed “method detection limits” and “method reporting limits,” respectively. Method detection limits and (or) method 

reporting limits could not be determined within the scope of this 

study because the data set of 15 sandbag and optical-brightener 

samples was statistically too small. These limits will be necessary in the future in order to report and analyze data with an 

acceptable degree of statistical certainty. Outliers are common 

in any assessment of natural bacterial populations. Data collected from sandbag samplers and natural sediment should be 

compared with caution because bacterial concentrations can 

vary substantially between the two data sets. As discussed previously, natural sediment is variable; because of this variability, 

outliers will likely be more common when sampling these natural sediments. 

Limitations of the Investigation

The sampling plan and data collected during this study 

were subject to the limitations of available laboratory equipment, field and laboratory personnel, time, and budgetary constraints. Some data sets within this study are statistically small, 

and additional data are required to increase the statistical certainty of some relations. Additional data also are required to 

quantify specific environmental parameters such as soil moisture, potential combined-sewer problems, bacterial regrowth, 

and (or) other parameters. Methods developed during the course 

of this study are preliminary and modifications are anticipated 

as more data become available. Potential improvements to 

methods are listed throughout the text where applicable. This 

study was conducted by sampling individual events over the 

course of 2 years. This sampling plan, therefore, resulted in the 

collection of individual “snapshots” during the 2-year period 

from which various determinations were made. Long-term 

(longer than 10 years) and (or) continuous data collection are 

generally required to make statistically sound determinations 

relating to any long-term trends. 

Competition for resources must be considered in the interpretation of any data regarding biofilms. As generally observed 

throughout nature, organisms and (or) assemblages of organisms present in the same ecological niche must compete for 

available resources and, ultimately, survival. Research has 

shown that biofilms are also subject to this same natural, competitive process. For example, Banning and others (2003) point 

out that, under certain conditions, biofilms may represent sites 

of intensified competition for limiting or specific nutrients. 

Simplified, this research suggests that biofilms can compete for 

limited resources and potentially destroy other, weaker biofilms. Changes in environmental conditions and (or) available 

resources within the fluvial environment may, therefore, prove 

detrimental for one type of bacteria and (or) beneficial for 

another. Consequently, localized areas of little or no bacterial 

contamination within fluvial sediments and (or) the water column may not be because of the lack of bacteria but instead the 

lack of conditions conducive to the persistence of that particular 
Summary and Conclusions 43

bacteria type. Although the specific study of this issue was 

beyond the scope of this study, an understanding of the potential 

effects on bacterial populations resulting from this concept is 

important in the interpretation of all bacterial data.

Summary and Conclusions 

Up to 99 percent of all bacteria within nature are present as 

sessile or attached bacteria; however, most current (2004) methods to assess bacteria only assess those bacteria that are planktonic, or free-floating, within the water column. These current 

methods, therefore, do not adequately assess the processes that 

effect the overall fluvial system; in effect, these methods identify the presence of the problem but not the extent. Assessment 

and understanding of the larger sessile bacteria population, as 

well as the planktonic population, is critical to understanding 

the biological and physical processes that drive various bacterial concentrations within the fluvial system. In cooperation 

with the Chester County Water Resources Authority and the 

Chester County Health Department, the U.S. Geological Survey 

(USGS) began a study in 2001 to identify potential sources of 

fecal-indicator bacteria within the West Branch Brandywine 

Creek in Chester County, Pa., gain a better understanding of 

bacteria occurrence and distribution within the fluvial system, 

and develop protocols to assist water-resource managers in the 

detection of point and nonpoint sources of fecal contamination 

within the fluvial system. 

The study encompassed two reaches of the West Branch 

Brandywine Creek—the Coatesville study reach and the Wagontown study reach. The Coatesville study reach is on the West 

Branch Brandywine Creek as it flows through the city of 

Coatesville, the Borough of South Coatesville, and the Borough 

of Modena. The Wagontown study reach is on the West Branch 

Brandywine Creek as it flows near the town of Wagontown, in 

Chester County, Pa. The Coatesville study reach flows through 

a predominantly urban/industrial region and the Wagontown 

study reach flows through a predominantly forested region. 

Sixty-four base-flow sampling sites, 15 stormflow sampling 

sites, and 15 sandbag sampling sites were located throughout 

the Coatesville study reach. Ten base-flow sampling sites were 

located throughout the Wagontown study reach; no storm samples were collected from this reach. 

Samples were collected and processed for various bacteria 

in natural fluvial sediment, the water column, and artificial sediments in samplers (sandbags). Samples collected from fluvial 

sediments were analyzed for E. coli, enterococcus, fecal 

coliform, and fecal streptococcus. Sediment samples were collected as single-point grab samples from wet, fluvial sediments 

exposed to flow from potential fecal-contamination sources. 

Samples collected from the water column were analyzed for 

E. coli, enterococcus, fecal coliform, and fecal streptococcus 

bacteria. Chemical measurements were made for temperature, 

dissolved oxygen, pH, turbidity, and specific conductance at all 

sites where bacteria samples were collected. Samples from 

selected sites on the Coatesville study reach were analyzed to 

detect potential wastewater constituents and (or) nutrients. Fifteen modified sandbag samplers installed along the Coatesville 

study reach were analyzed for E. coli and enterococci. All bacteria samples were analyzed at the Chester County Health 

Department Laboratory, and water-quality samples were analyzed at the USGS National Water-Quality Laboratory. Quality-assurance and quality-control techniques were applied to the 

collection of all samples following USGS guidelines. 

Complex processes control many of the factors that determine when, where, and how much bacteria will attach within 

the fluvial environment as well as the availability of those bacteria to enter the water column. These processes are related to 

natural factors, such as sediment particle size, climatic conditions, aquatic growth, and competing organisms; and (or) 

anthropogenic influences, such as impervious surfaces adjacent 

to the stream, stormwater-management practices, reduction of 

wetlands and riparian zones, presence of instream structures, 

and (or) variations in water quality. Also of note is that because 

of the complexity of the fluvial system, and the diverse biologic 

response to stresses within that system, various bacteria are not 

likely to correlate well with one another; this conclusion was 

indicated by the relative differences shown between E. coli and 

enterococci concentrations within similar fluvial environments. 

Data collected during this study indicate that particle distribution (grain size) is a potential factor controlling bacteria 

concentrations within fluvial sediments. E. coli had grater 

median concentrations in the particle-size range of 0.125 to 

0.5 mm (fine to medium sand) than in other particle-size 

classes, and enterococci had greater median concentrations in 

the particle-size range of 0.062 to 0.25 mm (silt and clay to fine 

sand) than in other particle-size classes. Further data are 

required from other fluvial systems to determine if a broad comparison between fluvial systems is possible or if these data are 

valid only for the West Branch Brandywine Creek. 

During 2003, six sites were sampled for nutrients and 

wastewater constituents along the Coatesville study reach. 

Analyses of the water-quality samples collected during base 

flow indicated nutrient such as dissolved nitrate plus nitrite 

nitrogen and total phosphorus ranged from 2.0 to 3.69 mg/L and 

0.008 to 0.091 mg/L, respectively. A large percentage of the 

total nutrient load originated from the Coatesville region. During stormflow, a similar pattern in nutrient loads was present 

along the Coatesville study reach. This pattern indicated that the 

urban/industrial Coatesville area had a more substantial effect 

on nutrient loads within the study reach than did the upstream 

agricultural areas. 

Wastewater constituents generally indicate direct fecal 

inputs to the fluvial system such as leaking sewer pipes, failed 

septic systems, combined sewer overflows, and illegal discharges. Samples were collected concurrently with nutrient 

samples and analyzed for wastewater constituents. Wastewater 

constituents during base flow in 2003 primarily originated from 

the Coatesville storm-sewer system. The primary storm sewer 

for the city of Coatesville tested positive for 20 of 69 wastewater constituents. By comparison, only 5 of 69 constituents were 
44 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

detected entering the upstream end of the study reach in the 

main channel of the West Branch Brandywine Creek. Water 

sampled from the downstream end of the study reach tested positive for 10 of 69 constituents suggesting that dilution had lowered many of the contaminant levels entering from the Coatesville storm sewer to below the method detection limit for the 

various wastewater constituents. During stormflow, 5 of 

69 constituents were detected at the upstream end of the study 

reach, 8 of 69 constituents were detected at the center of the 

study reach, and 7 of 69 constituents were detected at the downstream end of the study reach. These data indicated no significant increase in the detected number of wastewater constituents 

along the Coatesville study reach during stormflow and indicated point sources (culverts, pipes, and so forth) of fecal contamination within the Coatesville study reach were not the 

likely origin of bacteria contamination during stormflow on the 

West Branch Brandywine Creek. 

Impervious surfaces affected bacterial contamination. This 

result was most evident in 2002. Elevated concentrations of 

E. coli, in 2002, were found primarily in sediments at or near 

storm-sewer outfalls along the Coatesville study reach 

(although not all storm sewers had elevated bacterial concentrations). Elevated E. coli concentrations within fluvial sediments 

were generally in the upstream region of the Coatesville study 

reach. This upstream region contains most of the known stormsewer outfalls that directly enter the West Branch Brandywine 

Creek. 

During 2003, high concentrations of bacteria were 

observed within the sediments of the West Branch Brandywine 

Creek below the outfall of a wastewater-treatment facility. Concentrations of E. coli in fluvial sediments along this reach were 

as high as 100 times greater than the median concentration of 

the Coatesville study reach; however, bacteria concentrations 

within this stream reach during the previous year did not exceed 

levels that would be considered background. The origin of these 

bacteria was unknown; however, data interpretation indicate 

storm sewers may have been largely the cause for the detected 

bacterial concentrations within the fluvial sediments near the 

outfalls. Most sites with elevated bacteria concentrations were 

at or near the air/water interface at the edge of the active steam 

channel. 

Lower bacteria concentrations within the water column of 

the Wagontown study reach than in the Coatesville study reach 

were attributed to the lack of overland flows across paved areas 

and the effective filtration of runoff by adjacent wetlands and 

more substantial riparian zones. The median concentration of 

E. coli within the water column of the Wagontown study reach, 

during base-flow sampling in 2003, was 195 col/100 mL; 

within the water column of the Coatesville study reach, the 

median concentration of E. coli was 960 col/100 mL during the 

same period. The bacteria concentrations within the water column at the upstream end of the Coatesville study reach (above 

the city of Coatesville storm-sewer outfalls) were consistent 

with those observed along the Wagontown study reach. The 

median E. coli concentration for the first 900 ft of the Coatesville study reach was 300 col/100 mL during base flow in 2003. 

Bacterial data collected from fluvial sediments as part of 

this study could not with any certainty identify specific sites 

where sediment filtration was occurring and (or) failing along 

the West Branch Brandywine Creek because the sampling plan 

did not target this issue. Although climatic and runoff effects 

likely affect the observed concentrations of various bacteria 

along this reach, knowledge of the prior discharge of untreated 

sewage along with the observed elevated concentrations of bacteria adjacent to the wetland area indicate that some level of filtration is potentially occurring, or may have occurred along this 

reach. Additional study is required to support this observation. 

Dams or other instream structures can, and do, affect bacteria concentrations within the fluvial environment. However, 

the actual process remains unclear and requires additional 

study. 

The regression analysis of both base-flow and stormflow 

data did not yield statistically valid relations between E. coli

bacteria and turbidity. High turbidity levels usually can indicate 

higher bacterial concentrations, but the relation was too sporadic on the West Branch Brandywine Creek to use turbidity as 

a feasible surrogate to estimate bacteria concentrations. 

Analysis of sandbag samplers found that E. coli concentrations generally were similar in both the sandbags and natural 

sediments, and enterococci concentrations generally were lower 

in the sandbags than in natural sediments. The poor results for 

enterococci were likely because the particle distribution within 

the sandbags was too coarse and did not provide an environment 

that enterococci prefer to colonize; however, further study is 

required to confirm this conclusion. In addition to sandbag samplers, additional samplers were added to detect optical brighteners in the water column. Detection of optical brighteners, along 

with an elevated fecal-indicator bacteria concentration, is indicative of an anthropogenic source of fecal contamination. 

Results from this study found only two positive optical-brightener tests; both positive samplers were at the outfalls of wastewater-treatment facilities. The optical-brightener method has 

some limitations. This method can only be expected to produce 

a “positive’ or “negative” result and at concentrations that can 

not be quantified. 

Generally, throughout this study, previously suspected 

sources of elevated bacteria concentrations, such as wastewater-treatment facilities and on-lot sewage disposal systems, 

were not found to directly contribute to increased bacterial concentrations observed within the study area of the West Branch 

Brandywine Creek The primary sources of elevated bacteria 

concentrating throughout the study area were generally found to 

be related to natural processes occurring within the environment and anthropogenic influences centered around urban and 

industrial runoff issues. Whereas natural processes, such as climatic conditions, are generally beyond the control of waterresource managers, anthropogenic influences shown to effect 

bacterial concentrations in the West Branch Brandywine Creek 

can be corrected to potentially reduce bacterial concentrations 

within the fluvial environment. Reduction of nutrient loads 

from agricultural and urban areas can decrease aquatic growth 

within impoundment areas, thereby reducing the potential for 
Acknowledgments 45

bacterial regrowth. Restoration of wetland and riparian zones 

may allow for infiltration of surface-water runoff, thereby filtering out much bacteria by way of bank filtration. Implementing 

stormwater-runoff structures that promote infiltration and do 

not allow direct input of stormwater from urban areas to enter 

the steam may reduce bacteria levels by means of sediment filtration. Reducing streambank and streambed erosion may 

reduce bacteria concentrations during stormflows by minimizing the amount of sessile bacteria washed into the stream as the 

streambank and streambed are eroded. Detecting and eliminating direct inputs of sewage that result from aging infrastructure 

can obviously reduce the direct input of planktonic bacteria to 

the water column. In summary, a natural, functioning stream is 

more likely to have lower concentrations of bacteria in both the 

water column and the fluvial sediment than a stream that has 

been extensively modified by humans.

Acknowledgments

The author gratefully acknowledges the assistance of Mr. 

Ray Ajalli and Mr. James O’Brien of ISG Plate Inc. for providing safe, full access to the ISG Plate Inc. property. The historical 

insight, plans, and maps provided by Mr. Ajalli and Mr. 

O’Brien greatly assisted in the interpretation of data collected 

from within the steel mill property. Donald Wilkinson of the 

City of Coatesville also was instrumental in providing historical 

maps and current information on the location and condition of 

the storm-sewer system within the City of Coatesville. Richard 

Lutz of the Pennsylvania-American Water Company provided 

information on the processing of storm water by the wastewater-treatment facility that greatly assisted in the interpretation of 

data. Finally, Nanette Morrone and her staff at the Chester 

County Health Department made great efforts to implement 

new procedures and process the large volume of samples 

required by this study.

References Cited

Alm, E.W., Burke, J., and Spain, A., 2003, Fecal indicator bacteria are abundant in wet sand at freshwater beaches: Water 

Research, v. 37, p. 3,978-3,982.

Banning, N., Toze, S., and Mee, B., 2003, Persistence of biofilm-associated Escherichia coli and Pseudomonas aeruginosa in groundwater and treated effluent in a laboratory 

model system: Microbiology, v. 149, p. 47-55.

Bascom, Florence, and Stose, G.W., 1932, Geologic atlas of the 

United States, Coatesville-West Chester folio, Pennsylvania–Delaware: U.S. Geological Survey Folio 223, 34 p.

Byappanahalli, M., Fowler, F., Shively, D., and Whitman, R., 

2003, Ubiquity and persistence of Escherichia coli in a midwestern coastal stream: Applied and Environmental Microbiology, v. 8, p. 4,549-4,555.

Clesceri, L.S., Greenberg, A.E., and Eaton, A.D., eds., 1998, 

Standard methods for the examination of water and wastewater (20th ed.): Washington, D.C., American Public Health 

Association, American Water Works Association, and Water 

Environment Federation [variously paged].

Costerton, J.W., Stewart, P.S., and Greenberg, E.P., 1999, Bacterial biofilms a common cause of persistent infections: 

Science, v. 284, p. 1,318-1,322.

Davey, M.E., and O’Toole, G.A., 2000, Microbial biofilms—from ecology to molecular genetics: Microbiology 

and Molecular Biology Reviews, v. 64, p. 847-867.

Francy, D.S., and Gifford, A.M., 2002, Escherichia coli in the 

swash zone at four Ohio bathing beaches: U.S. Geological 

Survey Fact Sheet 134-02, 4 p.

Geesey, G.G., Mutch, R., Costerton, J.W., and Green, R.B., 

2003, Sessile bacteria—an important component of the 

microbial population in small mountain streams: Limnology 

and Oceanography, v. 23, no. 6, p. 1,214-1,223.

Gregory, M.B., and Frick, E.A., 2000, Fecal-coliform bacteria 

concentrations in streams of the Chattahoochee River 

National Recreation Area, Metropolitan Atlanta, Georgia, 

May-October 1994 and 1995: U.S. Geological Survey 

Water-Resources Investigations Report 00-4139, 8 p.

Hench, K.R., Bissonnette, G.K., Sexstone, A.J., Coleman, J.G., 

Garbutt, K., and Skousen, J.G., 2003, Fate of physical, chemical, and microbial contaminants in domestic wastewater following treatment by small constructed wetlands: Water 

Research, v. 37, p. 921-927.

Hunter, C., McDonald, A., and Beven, K., 1992, Input of fecal 

coliform bacteria to an upland stream channel in the Yorkshire dales: Water Resources Research, v. 28, p. 1,869-

1,876.

Langland, M.J., and Hainly, R.A., 1997, Changes in bottomsurface elevations in three reservoirs on the lower Susquehanna River, Pennsylvania and Maryland, following the January 1996 flood—implications for nutrient and sediment 

loads to Chesapeake Bay: U.S. Geological Survey WaterResources Investigations Report 97-4138, 34 p.

McFeters, G.A., Stuart, A.S., and Olson, S.B., 1978, Growth of 

heterotrophic bacteria and algal extracellular products in oligotrophic waters: Applied and Environmental Microbiology, v. 35, p. 383-391.

Myers, D.N., and Wilde, F.D., 1997, Biological indicators: 

U.S. Geological Survey Techniques of Water-Resources 

Investigations, book 9, chap. A7, 38 p.

Nix, P.G., and Merry, C.H., 1990, Use of sediment bags as a 

monitor of fecal contamination in streams: Bulletin of Environmental Contamination and Toxicology, v. 45, p. 864-869.

Otto, K., and Silhavy, T.J., 2002, Surface sensing and adhesion 

of Escherichia coli controlled by the Cpx-signaling 

pathway: Proceedings of the National Academy of Sciences, 

v. 99, p. 2,287-2,292.

Pennsylvania Department of Environmental Protection, 1999, 

Pennsylvania Code, Title 25, Chapter 93, Water Quality 

Standards: Commonwealth of Pennsylvania, 212 p. 
46 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

Potera, Carol, 1998, Studying slime: Environmental Health 

Perspectives, v. 106, 4 p.

Potera, Carol, 1999, Forging a link between biofilms and 

disease: Science, v. 283, p. 1,837-1,839.

Rasmussen, P.P., and Ziegler, A.C., 2003, Comparison and continuous estimates of fecal coliform and Escherichia coli bacteria in selected Kansas streams, May 1999 through April 

2002: U.S. Geological Survey Water-Resources Investigations Report 03-4056, 80 p.

Rogers, J.R., 2002, Why do bacteria colonize aquifer surfaces? 

Geochemical and nutrient controls of bacterial colonization 

of silicate surfaces: U.S. Geological Survey Open-File 

Report 02-89, 8 p.

Sloto, R.A., 1994, Geology, hydrology, and ground-water quality of Chester County, Pennsylvania: Chester County Water 

Resources Authority, Water-Resource Report 2, 127 p.

Todar, K., 2002, Pathogenic E. coli: University of WisconsinMadison Department of Bacteriology, accessed January 18, 

2003, at http://www.bact.wisc.edu/Bact330/lectureecoli

Town, D.A., 2001, Historical trends and concentrations of fecal 

coliform bacteria in the Brandywine Creek Basin, Chester 

County, Pennsylvania: U.S. Geological Survey WaterResources Investigations Report 01-4026, 46 p.

Tufford, D.L., and Marshall, W.D., 2002, Fecal coliform source 

assessment in a small, mixed land used watershed: Journal 

of the American Water Resources Association, v. 38, 

p. 1,625-1,635.

U.S. Environmental Protection Agency, 1994, National primary 

drinking water standards: EPA 810-F-94-001A, 8 p.

U.S. Geological Survey, variously dated, National field manual 

for the collection of water-quality data: U.S. Geological 

Survey Techniques of Water-Resources Investigations, book 

9, chaps. A1-A9, available online at 

http://pubs.water.usgs.gov/twri9A [Chapter updates and 

revisions are ongoing and are summarized at 

http://water.usgs.gov/owq/FieldManual/mastererrata.html].

U.S. Geological Survey, 2003, U.S. Geological Survey 

National Water-Quality Laboratory technical information: 

available online at http://wwwnwql.cr.usgs.gov/USGS/

[updates and revisions are ongoing].

Whitman, R.L., and Nevers, M.B., 2003, Foreshore sand as a 

source of Escherichia coli in nearshore water of a Lake 

Michigan beach: Applied Environmental Microbiology, 

v. 69, p. 5,555-5,562.

Whitman, R.L., Shively, D.A., Pawlik, H., Nevers, M.B., and 

Byappanahalli, M.N., 2003, Occurrence of Escherichia coli

and enterococci in Cladophora (Chlorophyta) in nearshore 

water and beach sand of Lake Michigan: Applied Environmental Microbiology, v. 69, p. 4,714-4,719.
Appendix 1–Site Descriptions
Table 1-1. Descriptions of base-flow sampling sites on Coatesville study reach, West Branch Brandywine Creek, 2002 and 2003, Chester County, Pen[~, approximately; USGS, U.S. Geological Survey; W.B., West Branch; SR, Pennsylvania State Route] Stream distance from upstream end of project reach (feet) U.S. Geological Survey project identification number2 U.S. Geological Survey station identification number Latitude Longitude Years sampled Site description Location of se

0 CB1 01480500 39°59′06.7′′ 75°49′37.2′′ 2002, 2003 Dam adjacent to USGS streamflow- gaging station 01480500. Streambed of W

behind dam channel. 178 CB4 01480502 39°59′05.1′′ 75°49′36.5′′ 2002 Mid-channel bar; directly upstream from abandoned concrete bridge. Edge of W.B. Bbar near do

326 CB5 01480506 39° 59′04.0′′ 75°49′35.2′′ 2002, 2003 Mid-channel bar; directly upstream of large railroad bridge. Edge of W.B. B

tip of bar. 361 CB6 395904075493401 39°59′04.1′′ 75°49′34.4′′ 2002 Outfall; ~0.5 ft diameter pipe, ~4 ft landward from left edge of water, under large railroad bridge. Dry in 2002. Edge of W.B. Bswale. 551 3CB7TC 395903075493301 39°59′02.8′′ 75°49′32.8′′ 2002, 2003 Outfall; Coatesville storm sewer, ~2-ft diameter pipe, ~30 ft landward from left edge of water. Flowing in 2002 and 2003. From bottom opipe, ~5 ft 

Brandywin

666 CB8 01480514 39°59′01.7′′ 75°49′32.4′′ 2002, 2003 Point bar on right bank; directly across from various Coatesville storm-sewer outfalls. Edge of W.B. B

bar. 898 CB9 395901075493101 39°59′01.0′′ 75°49′31.2′′ 2002, 2003 Outfall; Coatesville storm sewer, ~2-ft diameter pipe, ~30 ft landward from left edge of water. Dry in 2002 and 2003. Streambank at directly bel

1,040 CB9BTC 395900075493001 39°59′00.0′′ 75°49′30.1′′ 2003 Outfall; Coatesville storm sewer, ~2-ft diameter pipe, ~30 ft landward from left edge of water. Flowing in 2003. From bottom o

pipe, ~5 ft 

Brandywin

1,192 CB10 01480522 39°58′57.4′′ 75°49′28.8′′ 2002, 2003 Mid-channel bar with left-side channel leading to Coatesville storm-sewer outfall upstream under SR30 bridge. Outfall was dry in 2002 and flowing in 

2003.

From edge of W

right side odownstream 
1,395 CB11 395855075492801 39°58′55.2′′ 75°49′28.0′′ 2002, 2003 Outfall; Coatesville storm sewer, ~2-ft 

diameter pipe, ~30 ft landward from 

left edge of water. Dry in 2002 and 2003.

Streambank at 

directly bel

1,774 CB12 01480532 39°58′53.0′′ 75°49′28.4′′ 2002 Mid-channel bar. Edge of W.B. B

bar near the 

1,931 CB13 395850075492801 39° 58′50.0′′ 75°49′28.3′′ 2002 Outfall; 3, 1-3-ft diameter pipes in stonemasonry wall on right bank. Likely a 

storm sewer from mill. Dry in 2002.

Edge of W.B. B

largest pipe 

2,167 CB14 395848075492701 39° 58′48.0′′ 75°49′26.7 ′′ 2002, 2003 Outfall; 2-ft diameter pipe with concrete 

spillway ~15 landward from left edge of water. Dry in 2002 and 2003.

Edge of W.B. B

concrete sp

2,575 CB15 01480548 39°58′42.9′′ 75°49′23.1′′ 2002 Mid-channel bar directly downstream of 

low-head dam.

Edge of W.B. B

of bar.

2,991 4CB16TC 01480550 39°58′41.1′′ 75°49′21.0′′ 2002, 2003 Outfall; large brick and concrete culvert on 

left bank known as Gibbons Run. Gibbons Run is primary storm sewer for City of Coatesville. Flowing in 2002 and 2003.

Bed of Gibbon

3,085 CB17TC 395840075492001 39°58′40.1′′ 75°49′20.3′′ 2002, 2003 Outfall; 2-ft diameter culvert with stonemasonry spillway ~15 ft landward 

from left edge of water. Culvert is storm sewer that drains area above ISG Plate Inc. Flowing in 2002 and 2003.

Bottom edge o

(slightly abBrandywin

3,397 CB18TC 395837075491901 39°58′37.2′′ 75°49′19.4′′ 2002 Outfall; 2-ft diameter culvert in concrete 

wall ~10 ft landward from right edge 

of water. Flowing in 2002 and 2003.

Bottom of swal

culvert ~5 

Brandywin

3,835 CB19 01480564 39°58′33.8′′ 75°49′21.4′′ 2002, 2003 Mid-channel bar directly downstream of 

bridge leading into mill building.

Edge of W.B. B

tip of bar.

Table 1-1. Descriptions of base-flow sampling sites on Coatesville study reach, West Branch Brandywine Creek, 2002 and 2003, Chester County, Pen

—Continued

[~, approximately; USGS, U.S. Geological Survey; W.B., West Branch; SR, Pennsylvania State Route]

Stream 

distance from 

upstream end 

of project 

reach

(feet)

U.S. 

Geological 

Survey 

project 

identification 

number2

U.S. 

Geological 

Survey station 

identification 

number

Latitude Longitude Years sampled Site description Location of se
3,872 CB20TC 01480580 39°58′33.6′′ 75°49′22.5′′ 2002, 2003 Outfall; ~4-ft × 4-ft rectangular culvert in concrete wall below mill building on right bank. Known as Tar Run; culvert serves as Coatesville storm sewer and outfall for process water from ISG Plate Inc. Flowing in 2002 and 2003. Bed of Tar Run 4,411 4CB21TC 01480614 39°58′30.3′′ 75°49′27.8′′ 2003, 2003 Outfall; ~15-ft × 10-ft culvert in concrete wall below mill building on right bank. Known as Sucker Run; culvert serves as Coatesville storm sewer. Flowing in 2002 and 2003. At mouth of Su

edge of W.sediment w

4,677 CB22 014806141 39°58′26.8′′ 75°49′27.4′′ 2002 Point bar on left bank. Edge of W.B. B

bar. 4,853 CB23TC 395826075492701 39°58′25.7′′ 75°49′26.7′′ 2003, 2003 Pennsylvania American Water Company, sewage-treatment facility outfall on left bank. Flowing in 2002 and 2003. Edge of W.B. Bdownstream location whthe sedime

5,150 CB24 395823075492501 39°58′23.2′′ 75°49′25.2′′ 2002 Outfall; 2-ft diameter pipe with flap-type cover ~5 ft landward from left edge of water. Dry in 2002. Edge of W.B. B

swale leadi

5,574 CB25TC 395819075492401 39°58′19.0′′ 75°49′23.7′′ 2002, 2003 Outfall; ~4-ft × 4-ft culvert ~5 ft landward from left edge of water. Flowing in 2002 and 2003. Mouth of culve6,101 CB26 0148061452 39°58′14.0′′ 75°49′22.0′′ 2002, 2003 Mid-channel bar at downstream nose of pier #2 on railroad bridge, very small. Edge of W.B. B

tip of bar. 6,703 CB27 014806146 39°58′08.4′′ 75°49′19.4′′ 2002, 2003 Deep pool in W.B. Brandywine. Streambed, cenpool, in W.

7,183 CB28 014806147 39°58′04.7′′ 75°49′17.2′′ 2002, 2003 Point bar on left bank in W.B. Brandywine. Edge of W.B. B

bar. Table 1-1. Descriptions of base-flow sampling sites on Coatesville study reach, West Branch Brandywine Creek, 2002 and 2003, Chester County, Pen

—Continued [~, approximately; USGS, U.S. Geological Survey; W.B., West Branch; SR, Pennsylvania State Route] Stream distance from upstream end of project reach (feet) U.S. Geological Survey project identification number2 U.S. Geological Survey station identification number Latitude Longitude Years sampled Site description Location of se
7,201 CB29TC 395804075491601 39°58’ 04.1′′ 75°49′16.4′′ 2002, 2003 Outfall; ~4-ft × 7-ft concrete culvert ~5 ft 

landward from left edge of water. Flowing in 2002 and 2003.

Mouth of culve

7,481 CB30 395802075491501 39°58′01.5′′ 75°49′14.8′′ 2002, 2003 Outfall; 2-ft diameter culvert with concrete 

spillway ~10 ft landward from left edge of water. Dry in 2002, flowing in 2003 (too little to sample).

2002 sediment 

W.B. Brandspillway; 2mouth of c

7,747 4CB31TC 01480615 39°57′58.9′′ 75°49′14.1′′ 2002, 2003 Unnamed tributary channel on right bank 

near intersection of 1st Avenue and Newlinville Road in South Coatesville. Flowing in 2002 and 2003. 

Streambed of tr

upstream fr

7,906 CB32 0148061502 39°57′58.5′′ 75° 49′12.0′′ 2002, 2003 Pool in W.B. Brandywine. Streambed, cen

pool, in W.

8,170 CB33 0148061506 39° 57′57.7′′ 75° 49′08.7′′ 2002, 2003 Riffle in W.B. Brandywine. Streambed, cen

riffle, in W

8,446 CB34 0148061508 39° 57′57.3′′ 75°49’ 05.1′′ 2002 Run in W.B. Brandywine. Streambed, cen

run, in W.B

8,725 CB35TC 395758075490101 39°57′57.6′′ 75°49′01.4′′ 2002, 2003 Outfall; ~4-ft × 4-ft culvert ~2 ft landward 

from left edge of water. Culvert almost entirely plugged with sediment; serves as storm sewer for adjacent mill complex. Flowing in 2002 and 2003. 

Within culvert 

8,767 CB36 0148061516 39°57′57.1′′ 75°49′00.0′′ 2002 Point bar on left bank. Edge of W.B. B

tip of bar w

9,008 CB36B 0148061520 39°57′56.8′′ 75°48′57.8′′ 2002, 2003 Left streambank directly downstream of 

rip-rap spur dikes.

Edge of W.B. B

9,298 CB37 395756075485401 39°57′56.5′′ 75°48′54.3′′ 2002 Outfall; 2-ft diameter concrete culvert

~5 ft landward from left edge of water. 

Not flowing in 2002.

Mouth of culve

9,381 CB38 0148061526 39°57′56.7′′ 75°48′53.0′′ 2002, 2003 Left streambank where concrete wall 

meets left edge of water.

Edge of W.B. B

Table 1-1. Descriptions of base-flow sampling sites on Coatesville study reach, West Branch Brandywine Creek, 2002 and 2003, Chester County, Pen

—Continued

[~, approximately; USGS, U.S. Geological Survey; W.B., West Branch; SR, Pennsylvania State Route]

Stream 

distance from 

upstream end 

of project 

reach

(feet)

U.S. 

Geological 

Survey 

project 

identification 

number2

U.S. 

Geological 

Survey station 

identification 

number

Latitude Longitude Years sampled Site description Location of se
9,381 CB38BTC 395756075485301 39°57′56.0′′ 75°48′53.0′′ 2003 Spring, not flowing in 2002. Located ~15 ft landward from right edge of water. Within flow fro9,646 4CB39TC 395757075485001 39°57′57.1′′ 75°48′50.1′′ 2002 Outfall; 2-ft diameter concrete culvert in concrete wall forming left bank. Skimmer around outfall in 2002. Not flowing in 2002. Edge of W.B. B

pipe on left 

9,873 CB40TC 395757075484701 39°57′57.3′′ 75°48′46.9′′ 2002, 2003 Spring; located ~15 ft landward from right edge of water. Not flowing in 2002, flowing in 2003. 2002 sediment 

W.B. Brandformed by sediment tahowever, abBrandywin

10,034 CB41BTC 395758075484501 39°57′58.0′′ 75°48′45.0′′ 2003 Spring, not flowing in 2002. Located ~15 ft landward from right edge of water. Within flow fro10,144 CB41 0148061544 39°57′57.5′′ 75°48′43.5′′ 2002 Right streambank directly downstream of rip-rap. Edge of W.B. B10,340 CB42 0148061548 39°57′58.7′′ 75°48′41.1′′ 2002 Inlet; 20-ft × 10-ft gated inlet on left bank for mill process water. Edge of W.B. B

inlet on lef

10,905 4CB43 0148061552 39°57′59.7′′ 75°48′33.9′′ 2002, 2003 Dam locally known as Dam #4. Streambed of W

behind dam channel. 11,001 CB44 0148061556 39°57′59.8” 75°48′32.8′′ 2002, 2003 Mid-channel bar forming below plunge- pool at dam. Edge of W.B. Bof bar. 11,078 CB45 0148061558 39°58′00.2′′ 75°48′30.3′′ 2002 Pool in W.B. Brandywine in left channel near downstream tip of mid-channel bar. Streambed, cenpool, in W.

11,402 CB46TC 0148061560 39°58′01.0′′ 75°48′27.8′′ 2002 Outfall; 5-ft diameter concrete culvert with 

skimmer and access stairs. Not flowing in 2002.

Within culvert 

Table 1-1. Descriptions of base-flow sampling sites on Coatesville study reach, West Branch Brandywine Creek, 2002 and 2003, Chester County, Pen

—Continued

[~, approximately; USGS, U.S. Geological Survey; W.B., West Branch; SR, Pennsylvania State Route]

Stream 

distance from 

upstream end 

of project 

reach

(feet)

U.S. 

Geological 

Survey 

project 

identification 

number2

U.S. 

Geological 

Survey station 

identification 

number

Latitude Longitude Years sampled Site description Location of se
11,577 CB47TC 0148061562 39°58′00.7′′ 75°48′25.9′′ 2002, 2003 South Coatesville and Modena, sewagetreatment facility outfall on right bank. 

Rip-rap apron below outfall. Flowing in 2002 and 2003.

Directly below 

contacts th

11,604 CB48 0148061564 39°58′01.0′′ 75°48′25.2′′ 2002, 2003 Pool in W.B. Brandywine. Streambed, cen

pool, in W.

11,866 CB49 0148061568 39°58′00.3′′ 75°48′22.0′′ 2002, 2003 Point bar on right bank. Edge of W.B. B

tip of bar w

11,893 CB50 0148061572 39°58′00.4′′ 75°48′21.3′′ 2002 Riffle in W.B. Brandywine. Streambed, righ

riffle, in W

12,200 CB51 0148061576 39°57′59.1′′ 75°48′16.7′′ 2002 Point bar on right bank. Edge of W.B. B

tip of bar.

12,508 CB52TC 0148061580 39°57′57.5′′ 75°48′14.7′′ 2002, 2003 Outfall; two, 3-ft diameter corrugated steel 

culverts. Flowing in 2002 and 2003.

Within culvert 

12,862 CB55TC 0148061584 39°57′54.0′′ 75°48′14.8′′ 2002, 2003 Unnamed, small tributary channel on right 

bank. Not flowing in 2002, flowing in 2003. 

2002 sediment 

W.B. Brandformed by sediment tatributary ch

W.B. Brand

13,002 CB56 0148061588 39°57′53.2′′ 75°48′14.3′′ 2002, 2003 Pool in W.B. Brandywine. Streambed, cen

pool, in W.

13,224 CB57 0148061592 39°57′50.5′′ 75°48′15.4′′ 2002, 2003 Right streambank directly downstream of 

overhead pipeline

Edge of W.B. B

13,487 CB59 0148061596 39°57′47.7′′ 75°48′15.2′′ 2002 Left streambank at swale that leads to large 

storage tank observed to overflow in 2002. 

Edge of W.B. B

swale.

13,559 CB58TC 014806161 39°57′45.6′′ 75°48′14.0′′ 2002, 2003 Unnamed tributary channel formed by old 

mill race. Leads to various springs. Flowing in 2002 and 2003.

Streambed of tr

upstream fr

Table 1-1. Descriptions of base-flow sampling sites on Coatesville study reach, West Branch Brandywine Creek, 2002 and 2003, Chester County, Pen

—Continued

[~, approximately; USGS, U.S. Geological Survey; W.B., West Branch; SR, Pennsylvania State Route]

Stream 

distance from 

upstream end 

of project 

reach

(feet)

U.S. 

Geological 

Survey 

project 

identification 

number2

U.S. 

Geological 

Survey station 

identification 

number

Latitude Longitude Years sampled Site description Location of se
13,647 CB60 0148061597 39°57′45.5′′ 75°48′13.1′′ 2002, 2003 Point bar on left bank ~20 ft directly downstream of 0.5-ft diameter PVC pipe. Flowing in 2002 and 2003. Edge of W.B. B

tip of bar w

13,946 CB61TC 014806162 39°57′44.8′′ 75°48′12.0′′ 2002, 2003 Unnamed tributary channel on left bank immediately upstream from USGS streamflow-gaging station 01480617. Flowing in 2002 and 2003. Streambed of tr

upstream fr

14,355 CB62 014806168 39°57′42.3′′ 75°48′07.6′′ 2002, 2003 Right streambank below several older houses. Edge of W.B. B14,809 4CB64 01480617 39°57′41.2′′ 75°48′02.9′′ 2002, 2003 Mid-channel bar adjacent to USGS streamflow-gaging station 01480617. Edge of W.B. B

tip of bar. 14,862 CB66TC 0148061802 39°57′40.3′′ 75°48′01.5′′ 2002, 2003 Dennis Run. Streambed of tr

upstream fr

1All samples from the water column were collected directly from the thalweg, or most dominant flow, of the W.B. Brandywine, tributary, or pipe. 2U.S. Geological Survey project identification numbers are assigned in the order they were initially located and not in downstream order as are U.S. Geological Survey 3TC denotes that sample was collected from within flow originating from tributary channel or outfall. 4Also a stormflow sampling site. Table 1-1. Descriptions of base-flow sampling sites on Coatesville study reach, West Branch Brandywine Creek, 2002 and 2003, Chester County, Pen

—Continued [~, approximately; USGS, U.S. Geological Survey; W.B., West Branch; SR, Pennsylvania State Route] Stream distance from upstream end of project reach (feet) U.S. Geological Survey project identification number2 U.S. Geological Survey station identification number Latitude Longitude Years sampled Site description Location of se
Table 1-2. Descriptions of stormflow sampling sites on Coatesville study reach, West Branch Brandywine Creek, 2002 and 2003, Chester County, P[ft, feet; ~, approximately; W.B., West Branch; USGS, U.S. Geological Survey; SR, Pennsylvania State Route]

Stream 

distance from 

upstream end 

of project reach

(ft)

U.S. 

Geological 

Survey 

project 

identification 

number2

U.S. Geological 

Survey station 

identification 

number

Latitude Longitude Years sampled Site description

0 CBS6 01480500 39°59′11.2′′ 75°49′38.0′′ 2002, 2003 Bridge carrying Glencrest East Road over W.B. Br

upstream of USGS streamflow-gaging station 0

187 CBS7 01480504 39°59′04.8′′ 75°49′36.3′′ 2002, 2003 Abandoned concrete bridge immediately downstre

streamflow-gaging station 01480500.

1,019 CBS5 01480518 39°58′58.5′′ 75°49′29.1′′ 2002, 2003 Bridge carrying SR30 (Business) over W.B. Brand2,991 3,4CBS13TC 01480550 39°58′41.1′′ 75°49′21.0′′ 2002, 2003 Mouth of Gibbons Run culvert at confluence with W2,995 CBS12 01480552 39°58′40.7′′ 75°49′21.0” 2002, 2003 Bridge carrying private road within ISG Plate Inc. 

Brandywine; directly adjacent to Gibbons Run 

3,922 CBS10 01480584 39°58′32.9′′ 75°49′22.8′′ 2002, 2003 Bridge carrying private road within ISG Plate Inc. 

Brandywine; directly adjacent to Tar Run culve

4,411 4CBS9TC 01480614 39°58′30.3′′ 75°49′27.8′′ 2002, 2003 Mouth of Sucker Run culvert at confluence with W

by way of overhead walkway.

6,023 CBS15 014806145 39°58′14.4′′ 75°49′22.0′′ 2002, 2003 Bridge carrying railroad within ISG Plate Inc. prop

Sucker Run culvert and 1st Avenue bridge.

7,747 4CBS3TC 01480615 39°57′58.3′′ 75°49′14.4′′ 2002, 2003 Abandoned bridge over tributary to W.B. Brandywi

Avenue and Newlinville Road; sampling site is ~100 ft upstream from confluence with W.B. B

7,754 CBS4 0148061501 39°57′58.9′′ 75°49′13.0′′ 2002, 2003 Bridge carrying 1st Avenue over W.B. Brandywine 

Newlinville Road.

9,646 4CBS16TC 395757075485001 39°57′57.1′′ 75°48′50.1′′ 2002, 2003 Outfall; 2-ft diameter concrete culvert in concrete w

Skimmer around outfall in 2002. Not flowing i

10,905 4CBS19 0148061552 39°57′59.9′′ 75°48′33.9′′ 2002, 2003 Dam locally known as Dam #4; samples collected 

of spillway.

13,946 CBS21TC 01480616 39°57′46.8′′ 75°48′10.8′′ 2002, 2003 Abandoned bridge over unnamed tributary channel 

upstream from USGS streamflow-gaging statio~100 ft upstream from confluence with W.B. B

14,512 4CBS2 01480617 39°57′41.7′′ 75°48′04.9′′ 2002, 2003 Bridge carrying Union Street over W.B. Brandywin

gaging station 01480617.

14,862 CBS1TC 01480618 39°57′39.0′′ 75°48′02.8′′ 2002, 2003 Bridge carrying South Brandywine Avenue over D

upstream from confluence with W.B. Brandyw

1All samples from the water column were collected directly from the thalweg, or most dominant flow, of the W.B. Brandywine, tributary, or pipe.2U.S. Geological Survey project identification numbers are assigned in the order they were initially located and not in downstream order as are U.S. Geological Survey s3TC denotes that sample was collected from flow originating from tributary channel or outfall.4Also a base-flow sampling site. 
Table 1-3. Descriptions of base-flow sampling sites on Wagontown study reach, West Branch Brandywine Creek, 2002 and 2003, Chester County, Pe[ft, feet; ~, approximately; W.B., West Branch; SR, Pennsylvania State Route] Stream distance from upstream end of project reach (ft) U.S. Geological Survey project identification number2 U.S. Geological Survey station identification number Latitude Longitude Years sampled Site description Locat

0 A1 01480428 40°00′21.5′′ 75°49′32.4′′ 2002, 2003 Left streambank ~400 ft upstream of SR340 bridge. Left edge o

152 A2 04180429 40°00′20.1′′ 75°49′31.7′′ 2002, 2003 Right streambank, ~250 ft upstream of SR 340 bridge, where chute drains a small wetland area during higher flows. Right edge 

bottom flows t

662 A3 014804302 40°00′15.6′′ 75°49′28.5′′ 2002, 2003 Right streambank, ~250 ft downstream of SR 340 bridge, adjacent to parking area where runoff forms small sediment splay. Right edge 

small sarea. 982 A4 014804304 40°00′12.9′′ 75°49′ 26.5′′ 2002, 2003 Right streambank adjacent to area containing old storage tanks in the flood plain. Right edge 

1,100 A5 014804306 40°00′11.9′′ 75°49′25.9′′ 2002, 2003 Right side of W.B. Brandywine near a large boulder that captures sediment in flow shadow. Behind bo

have se

1,331 A6 014804308 40°00′09.6′′ 75°49′25.8′′ 2002, 2003 Small, pronounced rock riffle (weir) in W.B. Brandywine; destroyed by high flows in 2003. Right edge 

sedimebehind 

1,546 A7 400008075492601 40°00′07.5′′ 75°49′26.3′′ 2002, 2003 Spring, flowing in 2002 and 2003, that drains wetland area on right overbank. Right edge 

directl

1,816 A8 014804326 40°00′05.5′′ 75°49′28.2′′ 2002, 2003 Right streambank at chute that drains a wetland area during higher flows; wetland feeds various small springs, including site A7. Right edge 

bottom flows t

1,963 A9 014804328 40°00′04.0′′ 75°49′28.6′′ 2002, 2003 Left streambank ~200 ft upstream of U.S. 30-bypass bridge. Left edge o2,274 A10 01480433 40°00′01.2′′ 75°49′27.1′′ 2002, 2003 Right streambank ~100 ft downstream of U.S. 30-bypass bridge. Right edge 

1All samples from the water column were collected directly from the thalweg, or most dominant flow, of the W.B. Brandywine, tributary, or pipe. 2U.S. Geological Survey project identification numbers are assigned in the order they were initially located and not in downstream order as are U.S. Geological Survey 
Appendix 2–Coatesville Study Reach Data 

Tables
Table 2-1. Results of laboratory analyses and field determinations for bacteria concentrations in water and fluvial sediments at base flow on CoaWest Branch Brandywine Creek and tributaries, September 9, 2002, to September 12, 2002, Chester County, Pennsylvania. [ft, feet; col/100 mL, colonies per 100 milliliters; col/g, colonies per gram; mm, millimeter; <, less than] Stream distance from upstream end of project reach (ft) U.S. Geological Survey project identification number1 U.S. Geological Survey station identification number Date sampled (mm-dd-yyyy) Time sampled Escherichia coli in water (col/100 mL) Escherichia coli in sediment (col/g saturated sediment) 

0 CB1 01480500 09-09-2002 0734 90 70 

178 CB4 01480502 09-09-2002 0822 130 27 326 CB5 04180506 09-09-2002 0835 90 16 361 CB6 395904075493401 09-09-2002 0845 60 167 551 2CB7TC 395903075493301 09-09-2002 0854 290 11 666 CB8 01480514 09-09-2002 0907 120 3,510 898 CB9 395901075493101 09-09-2002 0915 70 8,100 

1,192 CB10 01480522 09-09-2002 0935 30 86 1,395 CB11 395855075492801 09-09-2002 0955 100 49 1,774 CB12 01480532 09-09-2002 1012 150 49 1,931 CB13 395850075492801 09-09-2002 1030 70 1,458 2,167 CB14 395848075492701 09-09-2002 1045 140 70 2,575 CB15 01480548 09-09-2002 1125 40 38 2,991 CB16TC 01480550 09-09-2002 1141 100 1,480 3,085 CB17TC 395840075492001 09-09-2002 1154 <1 12,150 3,397 CB18TC 395837075491901 09-10-2002 1230 <1 43 3,835 CB19 01480564 09-10-2002 1205 290 378 3,872 CB20TC 01480580 09-10-2002 1155 1,500 86 4,411 CB21TC 01480614 09-10-2002 1140 60 70 4,677 CB22 014806141 09-10-2002 1120 270 270 4,853 CB23TC 395826075492701 09-10-2002 1110 <1 92 5,150 CB24 395823075492501 09-10-2002 1050 310 3,240 5,574 CB25TC 395819075492401 09-10-2002 1035 <1 135 6,101 CB26 0148061452 09-10-2002 1000 380 43 6,703 CB27 014806146 09-10-2002 0945 380 119 7,183 CB28 014806147 09-10-2002 0925 310 216 7,201 CB29TC 395804075491601 09-10-2002 0910 10 124 
7,481 CB30 395802075491501 09-10-2002 0900 330 1,350 7,747 CB31TC 01480615 09-10-2002 0845 50 151 7,906 CB32 0148061502 09-10-2002 0830 490 178 8,170 CB33 0148061506 09-11-2002 1225 130 297 8,446 CB34 0148061508 09-11-2002 1215 310 54 8,725 CB35TC 395758075490101 09-11-2002 1151 160 8,100 8,767 CB36 0148061516 09-11-2002 1140 340 86 9,008 CB36B 0148061520 09-11-2002 1125 180 8 9,298 CB37 395756075485401 09-11-2002 1110 240 32 9,381 CB38 0148061526 09-11-2002 1055 300 14 9,646 CB39TC 395757075485001 09-11-2002 1035 20 3 9,873 CB40 395757075484701 09-11-2002 1015 410 324 

10,144 CB41 0148061544 09-11-2002 1000 440 27 10,340 CB42 0148061548 09-11-2002 0936 350 8 10,905 CB43 0148061552 09-11-2002 0915 710 119 11,001 CB44 0148061556 09-11-2002 0900 550 81 11,078 CB45 0148061558 09-11-2002 0845 400 59 11,402 CB46TC 0148061560 09-11-2002 0830 10 65 11,577 CB47TC 0148061562 09-12-2002 1220 <1 270 11,604 CB48 0148061564 09-12-2002 1218 100 8 11,866 CB49 0148061568 09-12-2002 1205 130 108 11,893 CB50 0148061572 09-12-2002 1150 50 16 12,200 CB51 0148061576 09-12-2002 1135 70 32 12,508 CB52TC 0148061580 09-12-2002 1115 <1 97 12,862 CB55 0148061584 09-12-2002 1057 250 173 13,002 CB56 0148061588 09-12-2002 1040 230 124 13,224 CB57 0148061592 09-12-2002 1024 120 92 13,487 CB59 0148061596 09-12-2002 0950 520 140 

Table 2-1. Results of laboratory analyses and field determinations for bacteria concentrations in water and fluvial sediments at base flow on Coa

West Branch Brandywine Creek and tributaries, September 9, 2002, to September 12, 2002, Chester County, Pennsylvania.—Continued

[ft, feet; col/100 mL, colonies per 100 milliliters; col/g, colonies per gram; mm, millimeter; <, less than]

Stream distance from 

upstream end of 

project reach

(ft)

U.S. Geological 

Survey project 

identification 

number1

U.S. Geological Survey 

station identification 

number

Date 

sampled

(mm-dd-yyyy)

Time 

sampled

Escherichia coli 

in water 

(col/100 mL)

Escherichia coli 

in sediment 

(col/g saturated 

sediment)
13,559 CB58TC 014806161 09-12-2002 0940 20 432 13,647 CB60 0148061597 09-12-2002 0926 390 297 13,946 CB61 014806162 09-12-2002 0910 430 65 14,355 CB62 014806168 09-12-2002 0850 290 16 14,809 CB64 01480617 09-12-2002 0830 260 378 14,862 CB66TC 0148061802 09-12-2002 0815 3,300 945 

1U.S. Geological Survey project identification numbers are assigned in the order they were initially located and not in downstream order as are U.S. Geological Su

numbers. 2TC denotes that sample was collected from flow originating from tributary channel or outfall. Table 2-1. Results of laboratory analyses and field determinations for bacteria concentrations in water and fluvial sediments at base flow on Coa

West Branch Brandywine Creek and tributaries, September 9, 2002, to September 12, 2002, Chester County, Pennsylvania.—Continued [ft, feet; col/100 mL, colonies per 100 milliliters; col/g, colonies per gram; mm, millimeter; <, less than] Stream distance from upstream end of project reach (ft) U.S. Geological Survey project identification number1 U.S. Geological Survey station identification number Date sampled (mm-dd-yyyy) Time sampled Escherichia coli in water (col/100 mL) Escherichia coli in sediment (col/g saturated sediment) 
Table 2-2. Results of field determinations for selected water-quality constituents at base flow on Coatesville study reach, West Branch Brandy

2002, to September 12, 2002, Chester County, Pennsylvania.1

[ft, feet; °C, degrees Celsius; mg/L, milligrams per liter; NTU, nephelometric turbidity units; μS/cm, microsiemens per centimeter at 25°C]

Stream distance 

from upstream end of 

project reach

(ft)

U.S. Geological 

Survey project 

identification 

number2

U.S. Geological 

Survey station 

identification number

Water

temperature

(°C)

Dissolved

oxygen

(mg/L)

 pH

(standard

units)

Turbidity 

(NTU)

0 CB1 01480500 17.7 8.4 7.5 6 

178 CB4 01480502 17.5 8.9 7.5 6 326 CB5 04180506 17.6 9.2 7.6 6 361 CB6 395904075493401 17.6 9.2 7.6 6 551 3CB7TC 395903075493301 17.6 9.5 7.5 6 666 CB8 01480514 17.7 9.8 7.6 5 898 CB9 395901075493101 18.0 9.8 7.7 5 

1,192 CB10 01480522 17.8 10.2 7.6 5 1,395 CB11 395855075492801 18.0 10.4 7.7 6 1,774 CB12 01480532 18.4 10.8 7.8 5 1,931 CB13 395850075492801 18.6 11.2 7.9 5 2,167 CB14 395848075492701 19.0 11.5 8.0 5 2,575 CB15 01480548 19.7 13.0 8.5 5 2,991 CB16TC 01480550 20.0 12.8 8.6 5 3,085 CB17TC 395840075492001 20.9 13.0 8.7 5 3,397 CB18TC 395837075491901 24.0 12.9 8.7 3 3,835 CB19 01480564 22.9 13.3 8.8 3 3,872 CB20TC 014806145 21.9 12.9 8.7 4 4,411 CB21TC 014806147 22.6 12.5 9.0 8 4,677 CB22 041806141 21.7 13.1 8.9 3 4,853 CB23TC 395826075492701 21.9 10.8 8.2 8 5,150 CB24 395823075492501 21.8 11.3 8.4 4 5,574 CB25TC 395819075492401 21.1 11.1 8.3 3 6,101 CB26 0148061452 20.6 10.6 8.0 3 6,703 CB27 014806146 20.2 10.1 7.9 3 7,183 CB28 014806147 19.9 9.1 7.8 3 7,201 CB29TC 395804075491601 19.7 8.8 7.7 3 7,481 CB30 395802075491501 19.5 8.6 7.6 3 
7,747 CB31TC 014806151 No data No data No data No data 7,906 CB32 0148061502 19.3 7.8 7.5 4 8,170 CB33 0148061506 22.4 12.4 8.8 4 8,446 CB34 0148061508 22.2 12.0 8.6 3 8,725 CB35TC 395758075490101 21.7 11.4 8.4 7 8,767 CB36 0148061516 21.6 11.0 8.5 3 9,008 CB36B 0148061520 21.4 10.8 8.4 3 9,298 CB37 395756075485401 21.0 9.5 8.1 4 9,381 CB38 0148061526 21.0 9.8 8.2 3 9,646 CB39TC 395757075485001 20.8 9.1 7.9 4 9,873 CB40 395757075484701 20.9 9.1 7.8 4 

10,144 CB41 0148061544 20.9 8.3 7.9 5 10,340 CB42 0148061548 21.2 6.2 7.8 4 10,905 CB43 0148061552 21.2 6.0 7.5 5 11,001 CB44 0148061556 21.4 7.4 7.6 6 11,078 CB45 0148061558 21.3 7.6 7.6 5 11,402 CB46TC 0148061560 21.5 7.5 7.6 5 11,577 CB47TC 0148061562 19.4 10.3 8.0 4 11,604 CB48 0148061564 19.4 10.3 8.0 4 11,866 CB49 0148061568 19.2 10.2 8.1 4 11,893 CB50 0148061572 19.5 10.4 8.1 3 12,200 CB51 0148061576 19.6 10.8 8.2 4 12,508 CB52TC 0148061580 19.6 10.8 8.1 3 12,862 CB55 0148061584 19.3 10.5 8.1 4 13,002 CB56 0148061588 19.0 10.1 8.0 4 13,224 CB57 0148061592 18.6 9.4 7.8 3 13,487 CB59 0148061596 18.3 8.4 7.7 3 

Table 2-2. Results of field determinations for selected water-quality constituents at base flow on Coatesville study reach, West Branch Brandy

2002, to September 12, 2002, Chester County, Pennsylvania.1—Continued

[ft, feet; °C, degrees Celsius; mg/L, milligrams per liter; NTU, nephelometric turbidity units; μS/cm, microsiemens per centimeter at 25°C]

Stream distance 

from upstream end of 

project reach

(ft)

U.S. Geological 

Survey project 

identification 

number2

U.S. Geological 

Survey station 

identification number

Water

temperature

(°C)

Dissolved

oxygen

(mg/L)

 pH

(standard

units)

Turbidity 

(NTU)
13,559 CB58TC 014806161 18.3 8.4 7.7 3 13,647 CB60 0148061597 18.2 7.9 7.7 3 13,946 CB61 014806162 18.1 7.7 7.6 3 14,355 CB62 014806168 18.2 7.5 7.6 3 14,809 CB64 01480617 18.1 7.6 7.5 2 14,862 CB66TC 0148061802 18.1 7.6 7.5 2 

1All water-quality constituents were measured within the main channel of the West Branch Brandywine Creek. 2U.S. Geological Survey project identification numbers are assigned in the order they were initially located and not in downstream order as are U.S. Geological Sur

numbers. 

3U.S. Geological Survey project identification numbers ending with TC indicate the measurement was made adjacent to the flowing tributary or outfall within the m

Branch Brandywine Creek.

Table 2-2. Results of field determinations for selected water-quality constituents at base flow on Coatesville study reach, West Branch Brandy

2002, to September 12, 2002, Chester County, Pennsylvania.1—Continued

[ft, feet; °C, degrees Celsius; mg/L, milligrams per liter; NTU, nephelometric turbidity units; μS/cm, microsiemens per centimeter at 25°C]

Stream distance 

from upstream end of 

project reach

(ft)

U.S. Geological 

Survey project 

identification 

number2

U.S. Geological 

Survey station 

identification number

Water

temperature

(°C)

Dissolved

oxygen

(mg/L)

 pH

(standard

units)

Turbidity 

(NTU)
Table 2-3. Results of field determinations for selected water-quality constituents at flowing tributaries to West Branch Brandywine Creek unde

Coatesville study reach, September 9, 2002, to September 12, 2002, Chester County, Pennsylvania.1 [ft, feet; °C, degrees Celsius; mg/L, milligrams per liter; NTU, nephelometric turbidity units; μS/cm, microsiemens per centimeter at 25°C] Stream distance from upstream end of project reach (ft) U.S. Geological Survey project identification number2 U.S. Geological Survey station identification number Water temperature (°C) Dissolved oxygen (mg/L) pH (standard units) Turbidity (NTU) 

551 CB7TC 395903075493301 16.0 9.4 7.4 9 

2,991 CB16TC 01480550 20.5 11.2 7.6 0 3,085 CB17TC 395840075492001 17.0 11.5 8.2 2 3,397 CB18TC 395837075491901 26.8 7.9 7.2 3 3,872 CB20TC 01480580 17.0 8.8 7.9 5 4,411 CB21TC 01480614 23.0 11.3 9.0 5 4,853 CB23TC 395826075492701 21.8 11.3 8.5 0 5,574 CB25TC 395819075492401 20.4 8.0 7.5 3 7,201 CB29TC 395804075491601 18.0 8.9 8.1 4 7,747 CB31TC 01480615 16.6 8.8 7.6 3 8,725 CB35TC 395758075490101 19.3 8.4 8.0 7 9,646 CB39TC 395757075485001 24.6 9.2 7.6 0 

11,402 CB46TC 0148061560 20.8 7.4 8.3 3 11,577 CB47TC 0148061562 22.1 8.6 7.1 0 12,508 3CB52TC 0148061580 No data No data No data No data 13,559 CB58TC 014806161 18.0 8.3 7.7 3 14,862 CB66TC 0148061802 15.4 7.6 7.0 2 

1All water-quality constituents were measured within flow from tributaries, springs, or outfalls to the West Branch Brandywine Creek. 2U.S. Geological Survey project identification numbers are assigned in the order they were initially located and not in downstream order as are U.S. Geological Su

numbers.3Insufficient flow to measure water-quality constituents with water-quality sonde.
Table 2-4. Results of laboratory analyses and field determinations for bacteria concentrations in water and selected water-quality constituents at sto

reach, West Branch Brandywine Creek and flowing tributaries, September 16, 2002, Chester County, Pennsylvania.1

[ft, feet; col/100 mL, colonies per 100 milliliters; °C, degrees Celsius; mg/L, milligrams per liter; NTU, nephelometric turbidity units; μS/cm, microsiemens per centimeter at 2

Stream distance 

from upstream end 

of project reach 

(ft)

U.S. Geological 

Survey project 

identification 

number2

U.S. Geological Survey 

station identification 

number

Time 

sampled

Escherichia coli

in water 

(col/100 mL)

Water

temperature

(°C)

Dissolved

oxygen

(mg/L)

 pH 

(standard 

units)

Tu

(

0 CBS6 01480500 1035 2,300 21.1 8.1 7.5 

187 CBS7 01480504 1030 1,300 20.9 8.8 7.6 

1,019 CBS5 01480518 1015 2,000 20.8 9.2 7.7 2,991 3CBS13TC 01480550 0940 <1 21.1 7.6 7.6 2,995 CBS12 01480552 0950 720 21.0 9.7 7.9 3,922 CBS10 01480584 0930 2,100 20.9 8.9 7.7 4,411 CBS9TC 01480614 0920 700 21.3 9.8 8.4 6,023 CBS15 014806145 0900 960 21.3 8.5 7.7 7,747 CBS3TC 01480615 0840 13,000 17.3 8.0 7.6 7,754 CBS4 0148061501 0846 1,800 21.1 8.1 7.6 9,646 CBS16TC 395757075485001 0830 970 23.7 7.1 7.6 

10,905 CBS19 0148061552 0815 3,300 21.3 6.0 7.5 13,946 CBS21TC 01480616 0800 330 18.8 8.0 7.7 14,512 CBS2 01480617 0740 9,000 21.5 6.8 7.5 14,862 CBS1TC 01480618 0730 70 18.5 7.9 7.3 

1Water-quality constituents were measured in flowing tributaries to the main channel of the West Branch Brandywine Creek where denoted by a “TC” suffix. 2U.S. Geological Survey project identification numbers are assigned in the order they were initially located and not in downstream order as are U.S. Geological Survey 3TC denotes that sample was collected from flow originating from tributary channel or outfall.
Table 2-5. Results of field determinations and laboratory analyses for bacteria concentrations in water and fluvial sediments at base flow on Coatesv

Branch Brandywine Creek and tributaries, July 7, 2003, to July 10, 2003, Chester County, Pennsylvania. [ft, feet; col/100 mL, colonies per 100 milliliters; col/g, colonies per gram; mm, millimeters; <, less than] Stream distance from upstream end of project reach (ft) U.S. Geological Survey project identification number1 U.S. Geological Survey station identification number Date sampled (mm-dd-yy) Time sampled Escherichia coli in water (col/100 mL) Enterococci in water (col/100 mL) Escherichia coli in sediment (col/g saturated sediment) Enteroco

in sedim

(col/g saturate

sedime

0 CB1 01480500 07-09-03 1043 270 990 5,994 3,240 

326 CB5 04180506 07-09-03 1030 420 760 16,200 4,266 

551 2CB7TC 395903075493301 07-09-03 1020 190 1,290 16,740 39,960 

666 CB8 01480514 07-09-03 1012 220 600 4,752 29,700 

898 CB9 395901075493101 07-09-03 1005 330 380 2,808 43,200 

1,040 CB9BTC 395900075493001 07-09-03 0945 420 1,380 61,560 22,140 1,192 CB10 01480522 07-09-03 0932 <1 <1 2,808 480,600 

1,395 CB11 395855075492801 07-09-03 0923 210 5,000 10,260 194,400 

2,167 CB14 395848075492701 07-09-03 0909 420 3,700 4,482 48,060 2,991 CB16TC 01480550 07-09-03 0845 <1 110 25,920 448,200 

3,085 CB17TC 395840075492001 07-09-03 0834 20 10 44,280 221,400 

3,835 CB19 01480564 07-09-03 0823 620 6,800 41,580 610,200 3,872 CB20TC 01480580 07-09-03 0818 4,400 36,000 11,880 54,540 4,411 CB21TC 01480614 07-09-03 0803 1,060 7,800 1,998 51,300 4,853 CB23TC 395826075492701 07-09-03 0750 80 700 2,106 189,000 5,574 CB25TC 395819075492401 07-08-03 1215 210 650 37,260 27,540 6,101 CB26 0148061452 07-08-03 1200 3,200 3,200 45,900 56,160 6,703 CB27 014806146 07-08-03 1151 2,100 4,200 124,200 480,600 7,183 CB28 014806147 07-08-03 1134 1,130 2,800 496,800 631,800 7,201 CB29TC 395804075491601 07-08-03 1115 80 370 28,620 5,767,200 7,481 CB30TC 395802075491501 07-08-03 1050 110 440 7,020 4,482 7,747 CB31TC 01480615 07-08-03 1040 150 250 1,728 4,482 

7,906 CB32 0148061502 07-08-03 1032 1,270 4,200 3,078 14,580 

8,170 CB33 0148061506 07-08-03 1015 1,420 3,000 34,560 340,200 

8,725 CB35TC 395758075490101 07-08-03 0947 11,000 36,000 345,600 399,600 

9,008 CB36B 0148061520 07-08-03 0933 940 3,900 1,620 57,780 
9,381 CB38 0148061526 07-08-03 0920 2,100 2,800 4,212 253,800 9,386 CB38BTC 395756075485301 07-08-03 0902 40 80 4,428 20,520 9,873 CB40TC 395757075484701 07-08-03 0836 180 460 11,340 22,140 

10,034 CB41BTC 395758075484501 07-08-03 0815 190 400 11,340 12,420 10,905 CB43 0148061552 07-07-03 1042 6,000 610 3,402 2,538 11,001 CB44 0148061556 07-07-03 1030 1,140 680 3,240 38,880 11,577 CB47TC 0148061562 07-07-03 1015 <1 <1 2,160 2,862 11,604 CB48 0148061564 07-07-03 1009 1,260 680 1,080 2,970 11,866 CB49 0148061568 07-07-03 1001 1,360 810 1,080 44,820 12,508 CB52TC 0148061580 07-07-03 0946 270 590 11,880 68,580 12,862 CB55TC 0148061584 07-07-03 0934 1,000 1,060 3,240 25,380 13,002 CB56 0148061588 07-07-03 0925 4,300 910 864 2,538 13,224 CB57 0148061592 07-07-03 0915 900 3,000 2,160 65,880 13,559 CB58TC 014806161 07-07-03 0901 300 610 2,160 1,728 13,647 CB60 0148061597 07-07-03 0848 960 3,000 38,340 28,620 13,946 CB61TC 014806162 07-07-03 0841 190 840 12,420 15,120 14,355 CB62 014806168 07-07-03 0834 780 2,500 2,646 6,588 14,809 CB64 01480617 07-07-03 0826 710 2,800 864 35,640 14,862 CB66TC 0148061802 07-07-03 0820 160 850 2,862 22,140 

1U.S. Geological Survey project identification numbers are assigned in the order they were initially located and not in downstream order as are U.S. Geological Survey 2TC denotes that sample was collected from flow originating from tributary channel or outfall.

Table 2-5. Results of field determinations and laboratory analyses for bacteria concentrations in water and fluvial sediments at base flow on Coatesv

Branch Brandywine Creek and tributaries, July 7, 2003, to July 10, 2003, Chester County, Pennsylvania.—Continued

[ft, feet; col/100 mL, colonies per 100 milliliters; col/g, colonies per gram; mm, millimeters; <, less than]

Stream 

distance from 

upstream end 

of project 

reach

(ft)

U.S. 

Geological 

Survey project 

identification 

number1

U.S. Geological 

Survey station 

identification

number

Date 

sampled

(mm-dd-yy)

Time 

sampled

Escherichia coli

in water 

(col/100 mL)

Enterococci 

in water

(col/100 mL)

Escherichia coli 

in sediment

(col/g 

saturated 

sediment)

Enteroco

in sedim

(col/g

saturate

sedime
Table 2-6. Results of field determinations for selected water-quality constituents at base flow on Coatesville study reach, West Branch BCreek, July 7, 2003, to July 10, 2003, Chester County, Pennsylvania.1 [ft, feet; °C, degrees Celsius; mg/L, milligrams per liter; NTU, nephelometric turbidity units; μS/cm, microsiemens per centimeter at 25°C] Stream distance from upstream end of project reach (ft) U.S. Geological Survey project identification number2 U.S. Geological Survey station identification number Water temperature (°C) Dissolved oxygen (mg/L) pH (standard units) Turbidity (NTU) 

0 CB1 01480500 21.4 9.1 7.5 7 

326 CB5 01480506 21.3 9.2 7.6 8 551 3CB7TC 395903075493301 21.3 9.3 7.6 8 666 CB8 01480514 21.3 9.3 7.6 8 898 CB9 395901075493101 21.3 9.3 7.6 8 

1,040 CB9BTC 395900075493001 21.2 9.1 7.6 8 1,192 CB10TC 01480522 21.0 8.8 7.5 8 1,395 CB11 395855075492801 21.0 9.0 7.5 8 2,167 CB14 395848075492701 21.2 9.2 7.5 8 2,991 CB16TC 01480550 21.3 9.3 7.7 8 3,085 CB17TC 395840075492001 21.3 9.4 7.7 8 3,835 CB19 01480564 21.2 9.1 7.6 8 3,872 CB20TC 01480580 21.2 9.1 7.6 8 4,411 CB21TC 01480614 21.2 8.9 7.6 8 4,853 CB23TC 395826075492701 21.0 8.8 7.4 8 5,574 CB25TC 395819075492401 22.5 10.2 8.2 19 6,101 CB26 0148061452 22.3 10.0 8.0 19 6,703 CB27 014806146 22.1 9.8 7.9 21 7,183 CB28 014806147 21.9 9.7 7.9 22 7,201 CB29TC 395804075491601 21.8 9.6 7.9 22 7,481 CB30TC 395802075491501 21.7 9.4 7.9 19 7,747 CB31TC 01480615 No data No data No data No data 7,906 CB32 0148061502 21.6 9.5 7.9 13 8,170 CB33 0148061506 21.5 9.6 7.9 12 8,725 CB35TC 395758075490101 21.3 9.4 7.8 11 9,008 CB36B 0148061520 21.3 9.2 7.8 11 9,381 CB38 0148061526 21.2 8.9 7.8 11 9,386 CB38BTC 395756075485301 21.2 8.9 7.8 11 9,873 CB40TC 395757075484701 21.0 8.8 7.7 11 
10,034 CB41BTC 395758075484501 21.0 8.7 7.6 11 10,905 CB43 0148061552 21.0 10.2 7.9 6 11,001 CB44 0148061556 21.0 9.9 7.9 6 11,577 CB47TC 0148061562 20.9 9.9 7.9 7 11,604 CB48 0148061564 20.9 9.9 7.8 7 11,866 CB49 0148061568 20.9 9.9 7.8 6 12,508 CB52TC 0148061580 20.8 9.8 7.8 7 12,862 CB55TC 0148061584 20.8 9.6 7.8 7 13,002 CB56 0148061588 20.7 9.6 7.8 9 13,224 CB57 0148061592 20.7 9.5 7.7 8 13,559 CB58TC 014806161 20.6 9.4 7.7 8 13,647 CB60 0148061597 20.5 9.4 7.7 9 13,946 CB61TC 014806162 20.4 9.3 7.5 9 14,355 CB62 014806168 20.4 9.3 7.6 9 14,809 CB64 01480617 20.5 9.4 7.6 8 14,862 CB66TC 0148061802 20.5 9.4 7.6 8 

1All water-quality constituents were measured within the main channel of the West Branch Brandywine Creek. 2U.S. Geological Survey project identification numbers are assigned in the order they were initially located and not in downstream order as are U.S. Geologi

identification numbers.

3TC denotes that sample was collected from flow originating from tributary channel or outfall.

Table 2-6. Results of field determinations for selected water-quality constituents at base flow on Coatesville study reach, West Branch B

Creek, July 7, 2003, to July 10, 2003, Chester County, Pennsylvania.1—Continued

[ft, feet; °C, degrees Celsius; mg/L, milligrams per liter; NTU, nephelometric turbidity units; μS/cm, microsiemens per centimeter at 25°C]

Stream distance 

from upstream end 

of project reach

(ft)

U.S. Geological 

Survey project 

identification 

number2

U.S. Geological Survey 

station identification 

number

Water

temperature

(°C)

Dissolved

oxygen

(mg/L)

 pH 

(standard 

units)

Turbidity 

(NTU)
Table 2-7. Results of field determinations for selected water-quality constituents at flowing tributaries to West Branch Brandywine Creek at 

study reach, July 7, 2003, to July 10, 2003, Chester County, Pennsylvania.1 [ft, feet; °C, degrees Celsius; mg/L, milligrams per liter; NTU, nephelometric turbidity units; μS/cm, microsiemens per centimeter at 25°C] Stream distance from upstream end of project reach (ft) U.S. Geological Survey project identification number U.S. Geological Survey station identification number Water temperature (°C) Dissolved oxygen (mg/L) pH (standard units) Turbidity (NTU) 

551 2CB7TC 395903075493301 16.5 9.8 7.4 9 

1,040 CB9BTC 095900075493001 16.0 4.4 6.6 12 1,192 CB10TC 01480522 19.4 9.1 7.4 0 2,991 CB16TC 01480550 16.6 9.7 7.5 3 3,085 CB17TC 395840075492001 14.8 10.2 7.0 5 3,872 CB20TC 01480580 15.3 9.1 7.4 2 4,411 CB21TC 01480614 19.4 9.7 8.0 5 4,853 CB23TC 395826075492701 20.8 8.9 7.3 No data 5,574 CB25TC 395819075492401 16.3 8.2 7.4 No data 7,201 CB29TC 395804075491601 15.8 9.0 7.5 2 7,481 CB30TC 395802075491501 No data No data No data No data 7,747 CB31TC 01480615 21.6 9.4 7.8 15 8,725 CB35TC 395758075490101 16.8 7.8 7.6 4 9,386 CB38BTC 395756075485301 12.8 10.5 6.8 0 9,873 CB40TC 395757075484701 15.7 9.7 7.3 25 

10,034 CB41BTC 395758075484501 19.0 9.4 7.9 12 11,577 CB47TC 0148061562 19.1 10.1 7.5 1 12,508 CB52TC 0148061580 15.4 6.5 7.3 3 12,862 CB55TC 0148061584 21.0 3.0 7.1 9 13,559 CB58TC 014806161 17.1 9.6 7.4 7 13,946 CB61TC 014806162 16.2 10.1 7.4 2 14,862 CB66TC 0148061802 16.7 10.4 7.3 4 

1All water-quality constituents were measured within flow from tributaries, springs, or outfalls to the West Branch Brandywine Creek. 2U.S. Geological Survey project identification numbers are assigned in the order they were initially located and not in downstream order as are U.S. Geologic

identification numbers.
Table 2-8. Wastewater constituents in water at base flow on Coatesville study reach, West Branch Brandywine Creek, July 10, 2003, Chester County[μg/L, micrograms per liter; <, less than; M, presence verified, not quantified; E, estimated value; shading indicates detected compound]

Wastewater constituent Reporting limit Unit U.S. Geological Survey station identification number 

01480500 01480550 01480615 395756075485301 

1,4-Dichlorobenzene 0.5 μg/L <0.5 <0.5 <0.5 <0.5 1-Methylnaphthalene .5 μg/L <.5 M <.5 <.5 2,6-Dimethylnaphthalene .5 μg/L <.5 <.5 <.5 <.5 2-Methylnaphthalene .5 μg/L <.5 <.5 <.5 <.5 3-beta-Coprostanol 2.0 μg/L <2 E 2 <2 <2 3-Methyl-1(H)-indole (Skatole) 1.0 μg/L <1 <1 <1 <1 3-tert-Butyl-4-hydroxy anisole (BHA) 5.0 μg/L <5 <5 <5 <5 4-Cumylphenol 1.0 μg/L <1 <1 <1 <1 4-n-Octylphenol 1.0 μg/L <1 <1 <1 <1 4-tert-Octylphenol 1.0 μg/L <1 <1 <1 <1 5-Methyl-1H-benzotriazole 2.0 μg/L <2 <2 <2 <2 Acetophenone .5 μg/L E .2 <.5 <.5 <.5 Acetyl hexamethyl tetrahydronaphthalene (AHTN) .5 μg/L <.5 E .3 <.5 <.5 Anthracene .5 μg/L <.5 <.5 <.5 <.5 Anthraquinone .5 μg/L <.5 <.5 <.5 <.5 Benzo[a]pyrene .5 μg/L <.5 <.5 <.5 <.5 Benzophenone .5 μg/L <.5 <.5 <.5 <.5 beta-Sitosterol 2.0 μg/L <2 E 1 <2 M beta-Stigmastanol 2.0 μg/L <2 <2 <2 <2 Bisphenol A 1.0 μg/L <1 <1 <1 <1 Bisphenol A, d3 (surrogate) .1 percent 100 118 112 96.0 Boron 13 μg/L 30 40 130 50 Bromacil .5 μg/L <.5 <.5 <.5 <.5 Bromoform .5 μg/L <.5 <.5 <.5 <.5 Caffeine .5 μg/L M .5 <0.5 <.5 Caffeine-C13 (surrogate) .1 percent 113 136 129 128 Camphor .5 μg/L <.5 <.5 <.5 <.5 Carbaryl 1.0 μg/L <1 <1 <1 <1 Carbazole .5 μg/L <.5 <.5 <.5 <.5 
Chloride 0.2 mg/L 23.5 7.5 32.2 20.6 Chlorpyrifos .5 μg/L <.5 <.5 <.5 <.5 Cholesterol 2.0 μg/L <2.0 6.0 <2.0 <2.0 Cotinine 1.0 μg/L <1.0 M <1.0 <1.0 d-Limonene .5 μg/L <.5 E .2 <.5 <.5 Decafluorobiphenyl (surrogate) .1 percent 69.6 90.9 83.3 80.0 Diazinon .5 μg/L <.5 <.5 <.5 <.5 Dichlorvos 1.0 μg/L <1.0 <1.0 <1.0 <1.0 Fluoranthene .5 μg/L <.5 <.5 E .1 <.5 Fluoranthene, d10 (surrogate) .1 percent 113 132 129 128 Hexadydrohexamethylcyclopentabenzopyran (HHCB) .5 μg/L <.5 E .1 <.5 <.5 Indole .5 μg/L <.5 <.5 <.5 <.5 Isoborneol .5 μg/L <.5 <.5 <.5 <.5 Isophorone .5 μg/L <.5 <.5 <.5 <.5 Isopropylbenzene .5 μg/L <.5 <.5 <.5 <.5 Isoquinoline .5 μg/L <.5 <.5 <.5 <.5 Menthol .5 μg/L <.5 E.2 <.5 <.5 Metalaxyl .5 μg/L <.5 <.5 <.5 <.5 Methyl salicylate .5 μg/L <.5 M <.5 <.5 Metolachlor .5 μg/L M M <.5 <.5 N,N-diethyl-meta-toluamide (DEET) .5 μg/L E .1 M E.1 <.5 Naphthalene .5 μg/L <.5 E .1 <.5 <.5 Nonylphenol, diethoxy- (total) 5.0 μg/L <5.0 <5.0 <5.0 <5.0 Octylphenol, diethoxy- 1.0 μg/L <1.0 <1.0 M <1.0 Octylphenol, monoethoxy- 1.0 μg/L <1.0 <1.0 <1.0 <1.0 p-Cresol 1.0 μg/L <1.0 M <1.0 <1.0 para-Nonylphenol (total) 5.0 μg/L <5.0 <5.0 <5.0 <5.0 Pentachlorophenol 2.0 μg/L <2.0 <2.0 <2.0 <2.0 Phenanthrene .5 μg/L <.5 <.5 <.5 <.5 

Table 2-8. Wastewater constituents in water at base flow on Coatesville study reach, West Branch Brandywine Creek, July 10, 2003, Chester County[μg/L, micrograms per liter; <, less than; M, presence verified, not quantified; E, estimated value; shading indicates detected compound]

Wastewater constituent Reporting limit Unit U.S. Geological Survey station identification number 

01480500 01480550 01480615 395756075485301 
Phenol 0.5 μg/L <0.5 0.9 1.1 0.8 Prometon .5 μg/L <.5 <.5 <.5 <.5 Pyrene .5 μg/L <.5 <.5 M <.5 Tetrachloroethylene .5 μg/L <.5 E .1 <.5 <.5 Tri(2-butoxyethyl)phosphate .5 μg/L <.5 <.5 <.5 <.5 Tri(2-chloroethyl)phosphate .5 μg/L <.5 <.5 <.5 <.5 Tributyl phosphate .5 μg/L <.5 <.5 <.5 <.5 Triclosan 1.0 μg/L <1.0 M <1.0 <1.0 Triethyl citrate (ethyl citrate) .5 μg/L <.5 <.5 <.5 <.5 Triphenyl phosphate .5 μg/L <.5 <.5 <.5 <.5 Tris(dichlorisopropyl)phosphate .5 μg/L <.5 <.5 <.5 <.5 

Table 2-8. Wastewater constituents in water at base flow on Coatesville study reach, West Branch Brandywine Creek, July 10, 2003, Chester County[μg/L, micrograms per liter; <, less than; M, presence verified, not quantified; E, estimated value; shading indicates detected compound]

Wastewater constituent Reporting limit Unit U.S. Geological Survey station identification number 

01480500 01480550 01480615 395756075485301 
Table 2-9. Nutrients in water at base flow on Coatesville study reach, West Branch Brandywine Creek, July 10, 2003, Chester County, Pennsylvania[mg/L, milligrams per liter; E, estimated value; <, less than] Nutrient name Reporting limit Unit U.S. Geological Survey station identification number 

01480500 01480550 01480615 395756075485301 0

Nitrogen, ammonia 0.041 mg/L <0.041 0.05 <0.041 <0.041 Nitrogen, ammonia + organic nitrogen, filtered .10 mg/L .30 .32 E .10 .14 Nitrogen, ammonia + organic nitrogen, unfiltered .10 mg/L .35 .39 .15 E .05 Nitrogen, nitrite .008 mg/L E .006 .012 <.008 <.008 Nitrogen, nitrite + nitrate .060 mg/L 3.18 3.69 2.76 2.00 Phosphorus, filtered .0044 mg/L .035 .083 .022 .008 Phosphorus, unfiltered .0037 mg/L .059 .091 .029 .008 Phosphorus, phosphate, ortho .018 mg/L .02 .07 E .01 <.02 
Table 2-10. Results of laboratory analyses and field determinations for bacteria concentrations in water and selected water-quality constituents at s

study reach, West Branch Brandywine Creek and flowing tributaries, August 4, 2003, Chester County, Pennsylvania.1

[ft, feet; col/100 mL, colonies per 100 milliliters; °C, degrees Celsius; mg/L, milligrams per liter; NTU, nephelometric turbidity units; μS/cm, microsiemens per centimeter at 2

Stream distance 

from upstream 

end of project 

reach 

(ft)

U.S. 

Geological 

Survey 

project 

identification 

number

U.S. Geological 

Survey station 

identification number

Time 

sampled

Escherichia coli 

in water

(col/100 mL)

Enterococci 

in water

(col/100 mL)

Water 

temperature 

(°C)

Dissolved 

oxygen

(mg/L)

 pH 

(standard 

units)

0 2CBS6 01480500 1033 17,000 73,000 21.8 7.1 7.5 

187 CBS7 01480504 1023 31,000 93,000 21.4 10.0 7.5 

1,019 CBS5 01480518 1015 17,000 106,000 21.3 11.0 7.5 2,991 3CBS13TC 01480550 1005 15,000 34,000 20.0 10.6 7.4 2,995 CBS12 01480552 0954 29,000 146,000 21.2 10.6 7.4 3,922 CBS10 01480584 0945 26,000 131,000 21.3 10.8 7.4 4,411 CBS9TC 01480614 0935 26,000 102,000 21.3 10.8 7.5 6,023 CBS15 014806145 0920 15,000 137,000 21.3 10.8 7.5 7,747 CBS3TC 01480615 0835 910 7,400 16.1 11.1 8.0 7,754 CBS4 0148061501 0845 23,000 137,000 21.2 9.9 7.4 9,646 CBS16TC 395757075485001 0910 13,000 97,000 20.8 12.8 8.2 

10,905 CBS19 0148061552 0900 7,000 147,000 21.3 10.1 7.4 13,946 CBS21TC 01480616 0821 4,900 70,000 19.5 9.7 7.2 14,512 CBS2 01480617 0755 13,000 89,000 22.3 4.8 7.7 14,862 CBS1TC 01480618 0810 40,000 166,000 19.3 10.7 7.2 

1Water-quality constituents in table were measured in flowing tributaries to the main channel of the West Branch Brandywine Creek where denoted by a “TC” suffix. 2U.S. Geological Survey project identification numbers are assigned in the order they were initially located and not in downstream order as are U.S. Geological Survey 3TC denotes that sample was collected from flow originating from tributary channel or outfall.
76 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

Table 2-11. Wastewater constituents in water at stormflow on Coatesville study reach, West Branch Brandywine Creek, August 4, 2003, 

Chester County, Pennsylvania.

[μg/L, micrograms per liter; <, less than; E, estimated value; M, presence verified, not quantified; shading indicates detected compound]

Wastewater constituent Reporting limit Unit

U.S. Geological Survey station 

identification number

01480500 0148061501 01480617

1,4-Dichlorobenzene 0.5 μg/L 1 <5.0 E 0.2 E 0.2

1-Methylnaphthalene .5 μg/L <5.0 <5.0 <5.0

2,6-Dimethylnaphthalene .5 μg/L <5.0 <5.0 <5.0

2-Methylnaphthalene .5 μg/L <5.0 <5.0 <5.0

3-beta-Coprostanol 2.0 μg/L <5 <5 <5

3-Methyl-1(H)-indole (Skatole) 1.0 μg/L <5 <5 <5

3-tert-Butyl-4-hydroxy anisole (BHA) 5.0 μg/L <5 <5 <5

4-Cumylphenol 1.0 μg/L <5 <5 <5

4-n-Octylphenol 1.0 μg/L <5 <5 <5

4-tert-Octylphenol 1.0 μg/L <5 <5 <5

5-Methyl-1H-benzotriazole 2.0 μg/L <5 <5 <5

Acetophenone .5 μg/L <5.0 <5.0 <5.0

Acetyl hexamethyl tetrahydronaphthalene (AHTN) .5 μg/L <5.0 <5.0 <5.0

Anthracene .5 μg/L <5.0 <5.0 E .3

Anthraquinone .5 μg/L <5.0 <5.0 <5.0

Benzo[a]pyrene .5 μg/L <5.0 E .3 E .4

Benzophenone .5 μg/L <5.0 <5.0 <5.0

beta-Sitosterol 2.0 μg/L <5 <5 <5

beta-Stigmastanol 2.0 μg/L <5 <5 <5

Bisphenol A 1.0 μg/L <5 M <5

Bisphenol A, d3 (surrogate) .1 percent 82.1 91.7 35.0

Boron 13 μg/L 20 30 30

Bromacil .5 μg/L <5.0 <5.0 <5.0

Bromoform .5 μg/L <5.0 <5.0 <5.0

Caffeine .5 μg/L <5.0 <5.0 <5.0

Caffeine-C13 (surrogate) .1 percent 82.1 104 59.1

Camphor .5 μg/L <5.0 <5.0 <5.0

Carbaryl 1.0 μg/L <5 <5 <5

Carbazole .5 μg/L <5.0 <5.0 <5.0

Chloride .2 mg/L 16.8 17.9 19.3

Chlorpyrifos .5 μg/L <5.0 <5.0 <5.0

Cholesterol 2.0 μg/L 8 <5 <5

Cotinine 1.0 μg/L <5 <5 <5

d-Limonene .5 μg/L <5.0 <5.0 <5.0

Decafluorobiphenyl (surrogate) .1 percent 136 95.8 77.3

Diazinon .5 μg/L <5.0 <5.0 <5.0

Dichlorvos 1.0 μg/L <5.00 <5.00 <5.00

Fluoranthene .5 μg/L E .3 .7 .8
Appendix 2 - Coatesville Study Reach Data Tables 77

Fluoranthene, d10 (surrogate) 0.1 percent 96.4 100 54.5

Hexadydrohexamethylcyclopentabenzopyran (HHCB) .5 μg/L <5.0 <5.0 <5.0

Indole .5 μg/L <5.0 <5.0 <5.0

Isoborneol .5 μg/L <5.0 <5.0 <5.0

Isophorone .5 μg/L <5.0 <5.0 <5.0

Isopropylbenzene .5 μg/L <5.0 <5.0 <5.0

Isoquinoline .5 μg/L <5.0 <5.0 <5.0

Menthol .5 μg/L <5.0 <5.0 <5.0

Metalaxyl .5 μg/L <5.0 <5.0 <5.0

Methyl salicylate .5 μg/L <5.0 <5.0 <5.0

Metolachlor .5 μg/L <5.0 <5.0 <5.0

N,N-diethyl-meta-toluamide (DEET) .5 μg/L .6 .6 <5.0

Naphthalene .5 μg/L <5.0 E .1 E .1

Nonylphenol, diethoxy- (total) 5.0 μg/L <5 <5 <5

Octylphenol, diethoxy- 1.0 μg/L <5 <5 <5

Octylphenol, monoethoxy- 1.0 μg/L <5 <5 <5

p-Cresol 1.0 μg/L <5 <5 <5

para-Nonylphenol (total) 5.0 μg/L <5 <5 <5

Pentachlorophenol 2.0 μg/L <5 <5 <5

Phenanthrene .5 μg/L <5.0 <5.0 E.3

Phenol .5 μg/L 1.0 <5.0 <5.0

Prometon .5 μg/L <5.0 <5.0 <5.0

Pyrene .5 μg/L E .3 .6 .7

Tetrachloroethylene .5 μg/L <5.0 <5.0 <5.0

Tri(2-butoxyethyl)phosphate .5 μg/L <5.0 2 <5.0

Tri(2-chloroethyl)phosphate .5 μg/L <5.0 <5.0 <5.0

Tributyl phosphate .5 μg/L <5.0 <5.0 <5.0

Triclosan 1.0 μg/L <5 <5 <5

Triethyl citrate (ethyl citrate) .5 μg/L <5.0 <5.0 <5.0

Triphenyl phosphate .5 μg/L <5.0 <5.0 <5.0

Tris(dichlorisopropyl)phosphate .5 μg/L <5.0 <5.0 <5.0

1

Reporting limit raised to 5.0 in most samples at request of U.S. Geological Survey National Water-Quality Laboratory because of large amounts of 

suspended solids in storm samples; where possible, original reporting limit was maintained.

Table 2-11. Wastewater constituents in water at stormflow on Coatesville study reach, West Branch Brandywine Creek, August 4, 2003, 

Chester County, Pennsylvania.—Continued

[μg/L, micrograms per liter; <, less than; E, estimated value; M, presence verified, not quantified; shading indicates detected compound]

Wastewater constituent Reporting limit Unit

U.S. Geological Survey station 

identification number

01480500 0148061501 01480617
78 Fecal-Indicator Bacteria and Identification of Fecal-Contamination Sources in Reaches of W.B. Brandywine Creek

Table 2-12. Nutrients in water at stormflow on Coatesville study reach, West Branch Brandywine Creek,

August 4, 2003, Chester County, Pennsylvania. 

[mg/L, milligrams per liter; E, estimated value]

Parameter name Reporting

limit Unit

U.S. Geological Survey 

station identification number

01480500 0148061501 01480617

Nitrogen, ammonia 0.041 mg/L E 0.04 E 0.03 E 0.02

Nitrogen, ammonia + organic nitrogen, filtered .10 mg/L .45 .50 .39

Nitrogen, ammonia + organic nitrogen, unfiltered .10 mg/L .98 2.4 2.0

Nitrogen, nitrite .008 mg/L .008 .019 .009

Nitrogen, nitrite + nitrate .060 mg/L 2.14 2.00 2.18

Phosphorus, filtered .0044 mg/L .060 .091 .087

Phosphorus, unfiltered .0037 mg/L .28 .80 .67

Phosphorus, phosphate, ortho .018 mg/L .04 .06 .06
Appendix 3–Wagontown Study Reach Data 

Tables
Table 3-1. Results of laboratory analyses and field determinations for bacteria concentrations in water and fluvial sediments at base flow on WaWest Branch Brandywine Creek and tributaries, September 18, 2002, Chester County, Pennsylvania. [ft, feet; col/100 mL, colonies per 100 milliliters; col/g, colonies per gram; mm, millimeters; <, less than] Stream distance from upstream end of project reach (ft) U.S. Geological Survey project identification number U.S. Geological Survey station identification number Date sampled (mm-dd-yyyy) Time sampled Fecal coliform bacteria in water (col/100 mL) Fecal streptococci bacteria in water (col/100 mL) Fecal coliform bacteria in sediment (col/g saturated sediment) Fecal streptococ

bacteria i

sediment (col/g saturated sediment

0 A1 01480428 09-18-2002 0842 80 480 378 540 

152 A2 01480429 09-18-2002 0905 160 370 0 324 662 A3 014804302 09-18-2002 1135 140 260 6,480 2,214 982 A4 014804304 09-18-2002 1120 180 290 702 108 

1,100 A5 014804306 09-18-2002 1106 100 350 3,240 594 1,331 A6 014804308 09-18-2002 1050 160 230 270 216 1,546 A7 400008075492601 09-18-2002 1030 190 270 1,674 24,840 1,816 A8 014804326 09-18-2002 1015 240 290 270 1,458 1,963 A9 014804328 09-18-2002 1000 190 370 108 3 2,274 A10 01480433 09-18-2002 0945 180 480 1,944 270 
Table 3-2. Results of field determinations for selected water-quality constituents at base flow on Wagontown study reach, West Branch Brandywine Creek, September 18, 2002, Chester County, Pennsylvania.1[ft, feet; °C, degrees Celsius; mg/L, milligrams per liter; NTU, nephelometric turbidity units; μS/cm, microsiemens per centimeter at 25°C]

Stream distance 

from upstream end 

of project reach 

(ft)

U.S. Geological 

Survey 

project 

identification 

number2

U.S. Geological Survey 

station identification 

number

Water 

temperature 

(°C)

Dissolved 

oxygen 

(mg/L)

 pH 

(standard 

units)

Turbidity 

(NTU)

Specif

conducta

(μS/cm

0 A1 01480428 17.1 9.3 7.6 5 204

152 A2 01480429 17.1 9.5 7.7 5 204662 A3 014804302 18.1 10.0 7.9 4 202982 A4 014804304 18.0 10.2 8.0 4 142

1,100 A5 014804306 18.0 10.2 8.0 4 2021,331 A6 014804308 17.8 10.2 7.9 5 2031,546 A7 400008075492601 17.7 10.2 8.0 4 2031,816 A8 014804326 17.4 10.1 7.8 5 2121,963 A9 014804328 17.1 10.0 7.7 5 2142,274 A10 01480433 17.0 10.0 7.7 5 216

1All water-quality constituents were measured within the main channel of the West Branch Brandywine Creek. 

2U.S. Geological Survey project identification numbers are assigned in the order they were initially located and not in downstream order as ar

Geological Survey station identification numbers.
Table 3-3. Results of laboratory analyses and field determinations for bacteria concentrations in water and fluvial sediments at bas

reach, West Branch Brandywine Creek and tributaries, July 17, 2003, Chester County, Pennsylvania. [ft, feet; col/100 mL, colonies per 100 milliliters; col/g, colonies per gram; mm, millimeters; <, less than] Stream distance from upstream end of project reach (ft) U.S. Geological Survey project identification number U.S. Geological Survey station identification number Date sampled Time sampled Escherichia coli in water (col/100 mL) Enterococci in water (col/100 mL) Escherichia coli in sediment (col/g saturated sediment) Enterococci in sediment (col/g saturated sediment) Ob

se

pa

dist

(

0 A1 01480428 07-17-2003 1045 110 570 1,890 4,050 0.5

152 A2 01480429 07-17-2003 1035 50 230 5,616 178,200 0.1662 A3 014804302 07-17-2003 1020 140 240 1,134 8,100 0.5982 A4 014804304 07-17-2003 1007 400 12,000 648 1,998 0.5

1,100 A5 014804306 07-17-2003 1012 380 310 1,458 46,980 1.-1,331 A6 014804308 07-17-2003 1000 1,210 280 216 19,980 0.51,546 A7 400008075492601 07-17-2003 0945 280 620 162 756 0.21,816 A8 014804326 07-17-2003 0917 210 500 4,752 2,700 <0.01,963 A9 014804328 07-17-2003 0912 160 310 2,322 3,780 1.-2,274 A10 01480433 07-17-2003 0900 180 520 1,404 17,280 0.2
Table 3-4. Results of field determinations for selected water-quality constituents at base flow on Wagontown study reach, W

Creek, July 17, 2003, Chester County, Pennsylvania.1

[ft, feet; °C, degrees Celsius; mg/L, milligrams per liter; NTU, nephelometric turbidity units; μS/cm, microsiemens per centimeter at 25°C]

Stream distance 

from upstream 

end of project 

reach

(ft)

U.S. Geological 

Survey 

project 

identification 

number2

U.S. Geological 

Survey 

station 

identification 

number

Water 

temperature 

(°C)

Dissolved 

oxygen 

(mg/L)

 pH 

(standard 

units)

Turbidity 

(NTU)

Specific 

conductanc

(μS/cm)

0 A1 01480428 20.3 10.0 7.9 2 230

152 A2 01480429 20.2 10.1 7.9 4 230662 A3 014804302 20.0 9.9 7.9 2 232982 A4 014804304 20.0 10.0 7.8 2 232

1,100 A5 014804306 20.0 10.0 7.8 3 2321,331 A6 014804308 19.9 10.0 7.8 3 2321,546 A7 400008075492601 19.9 10.0 7.6 4 2331,816 A8 014804326 19.3 9.9 7.7 4 2391,963 A9 014804328 19.0 9.9 7.6 3 2432,274 A10 01480433 19.1 9.9 7.5 3 243

1All water-quality constituents were measured within the main channel of the West Branch Brandywine Creek. 2U.S. Geological Survey project identification numbers are assigned in the order they were initially located and not in downstream order a

are U.S. Geological Survey station identification numbers. 

Appendix 4–Sandbag and Optical Brightener 

Data Table
Table 4-1. Descriptions of sandbag-sampling sites and laboratory determinations for bacteria concentrations and optical-brightener presence on July 3, 2003, to July 10, 2003, West Branch Brandywine Creek, Chester County, Pennsylvania. [ft, feet; col/g, colonies per gram; W.B., West Branch; ~, approximately] Stream distance from upstream end of project reach (ft) U.S. Geological Survey project identification number1 U.S. Geological Survey station identification number Description of sandbag location and attachment point Escherichia coli concentration within sandbag (col/g saturated sediment) Enteroco

concentra

within san

(col/g saturate

sedimen

0 CB1 01480500 Along right bank of W.B. Brandywine; ~5 ft upstream of dam crest; attached to tree on streambank 550 13,200 

1,040 CB9BTC 395900075493001 At mouth of Coatesville storm sewer culvert, ~30 ft landward from left edge of water; attached to debris at mouth of culvert. 110,000 324,500 2,991 CB16TC 01480550 At mouth of Coatesville storm sewer culvert (Gibbons Run); attached to culvert. 121,000 58,850 3,872 CB20TC 01480580 At mouth of Coatesville storm sewer and industrial process water outfall (Tar Run); attached to culvert. 28,050 47,850 4,411 CB21TC 01480614 At mouth of Coatesville storm sewer culvert (Sucker Run); attached to culvert. 5,995 36,300 4,853 CB23TC 395826075492701 At mouth of Pennsylvania American Water Company, wastewater-treatment facility culvert; attached to culvert. 715 5,115 7,747 CB31TC 01480615 Under abandoned bridge over tributary to W.B. Brandywine near intersection of 1st Avenue and Newlinville Road; attached to bridge. 110 2,310 8,725 CB35TC 395758075490101 Approximately 4 ft back from mouth into a ~4-ft × 4-ft storm- sewer culvert that serves industrial area; attached to culvert. 4,950 3,300 9,381 CB38BTC 395756075485301 At source of spring located ~15 ft landward from right edge of water; attached to tree at spring. 3,080 29,150 

10,034 CB41BTC 395758075484501 At source of spring located ~15 ft landward from right edge of water; attached to tree at spring. 1,760 3,465 11,577 CB47TC 0148061562 At mouth of corrugated steel pipe discharging effluent from South Coatesville and Modena, wastewater-treatment facility; attached to culvert. 12,100 7,590 13,559 CB58TC 014806161 At abandoned lock structure within unnamed tributary channel, formed by old mill race, approximately 15 ft upstream from confluence with W.B. Brandywine; attached to lock. 385 25,300 
13,946 CB61 014806162 Under abandoned bridge over unnamed tributary channel 

~100 ft upstream from confluence with W.B. Brandywine; 

attached to bridge.

2,695 5,060 

14,809 CB64 01480617 On downstream right side of mid-channel bar adjacent to USGS 

streamflow-gaging station 01480617; attached to tree.

1,650 6,325 

14,862 CB66TC 0148061802 Under bridge Carrying South Brandywine Avenue over Dennis 

Run ~100 ft upstream from confluence with W.B. 

Brandywine; attached to bridge.

715 2,750 

1U.S. Geological Survey project identification numbers are assigned in the order they were initially located and not in downstream order as are U.S. Geological Surv

numbers. 

Table 4-1. Descriptions of sandbag-sampling sites and laboratory determinations for bacteria concentrations and optical-brightener presence on 

July 3, 2003, to July 10, 2003, West Branch Brandywine Creek, Chester County, Pennsylvania.—Continued

[ft, feet; col/g, colonies per gram; W.B., West Branch; ~, approximately]

Stream 

distance from 

upstream end 

of project 

reach

(ft)

U.S. Geological 

Survey project 

identification 

number1

U.S. Geological 

Survey 

station identification 

number

Description of sandbag location 

and attachment point

Escherichia coli

concentration 

within sandbag

(col/g

saturated 

sediment)

Enteroco

concentra

within san

(col/g

saturate

sedimen

Appendix 5–2003 Streamflow-Gaging Station 

01480617 Data Table
Table 5-1. Results of laboratory analysis and field determinations for selected water-quality constituents and bacteria concentrations in water ical Survey streamflow-gaging station 01480617, West Branch Brandywine Creek at Modena, August 4, 2003, Chester County, Pennsylvania1 [ft3/s, cubic feet per second; col/100 mL, colonies per 100 milliliters; °C, degrees Celsius; mg/L, milligrams per liter; NTU, nephelometric turbidity units; μS/cm, microcentimeter at 25°C] Time Streamflow (ft3/s) Escherichia coli (col/100 mL) Enterococci (col/100 mL) Water temperature (°C) Dissolved oxygen (mg/L) pH (standard units) Turbidity (NTU) 

0558 817 7,800 19,000 22.5 4.9 7.6 400 0628 569 32,000 110,000 23.2 4.8 8.1 440 0658 360 32,000 110,000 23.1 4.7 8.2 360 0728 470 33,000 98,000 22.8 4.7 8.0 360 0758 418 11,000 116,000 22.3 4.8 7.7 330 0828 314 8,000 76,000 22.1 4.9 7.6 920 0858 251 18,000 92,000 22.1 4.9 7.6 780 0928 209 19,000 127,000 22.0 4.9 7.5 570 0958 184 19,000 42,000 22.1 5.0 7.5 480 1028 169 25,000 147,000 22.2 5.0 7.5 380 1058 164 14,000 155,000 22.3 5.0 7.5 340 

1All water-quality constituents were measured within the main channel of the West Branch Brandywine Creek. 
Glossary 91

Glossary

The terms in this glossary were compiled from numerous 

sources. Some definitions have been modified for use within the 

report.

Aliquot A portion of a solution or sample.

Fluvial Relating to a river or stream; as in 

“fluvial sediment.”

Lacustrine Relating to a lake; as in “lacustrine 

sediment.”

Planktonic Passively floating or weakly 

swimming; as in “planktonic bacteria.”

Quartzose Composed mainly of quartz; as in 

“quartzose sandstone.”

Riparian Relating to, living, or located on the 

bank of a river or stream; as in “riparian zone.”

Run-of-the river dam A dam that cannot store 

large amounts of water and must allow water to 

pass (generally over a spillway) at the same rate 

at which it enters the impoundment area.

Sessile Attached, not free to move; as in 

“sessile bacteria.”

Thalweg The deepest, highest velocity, path of 

the stream. 

Throughflow The lateral movement of water 

through the shallow, unsaturated zone during and 

immediately after a precipitation event.