Escherichia coli and Suspended Sediment in Berger Ditch 

at Maumee Bay State Park, Oregon, Ohio, 2006 

U.S. Department of the Interior

U.S. Geological Survey

Open-File Report 2007–1244
Cover. Clockwise from upper left—

A. Staff gage in Berger Ditch at Maumee Bay State Park, Oregon, Ohio.

B. U.S. Geological Survey gage house near Berger Ditch.

C. Looking downstream at staff gage in Berger Ditch from Cedar Point Road bridge.

D. Automatic sampler at gage house at Berger Ditch, Oregon, Ohio (station number 04194085). 
Escherichia coli and Suspended Sediment 

in Berger Ditch at Maumee Bay State Park, 

Oregon, Ohio, 2006 

By Amie M.G. Brady

Open-File Report 2007–1244

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

DIRK KEMPTHORNE, Secretary

U.S. Geological Survey

Mark D. Myers, Director

U.S. Geological Survey, Reston, Virginia: 2007

 

For product and ordering information:

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

Telephone: 1-888-ASK-USGS

For more information on the USGS--the Federal source for science about the Earth, its natural and living resources, 

natural hazards, and the environment:

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

Telephone: 1-888-ASK-USGS

Any use of trade, product, or firm names 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:

Brady, A.M.G., 2007, Escherichia coli and suspended sediment in Berger Ditch at Maumee Bay State Park, Oregon, 

Ohio, 2006: U.S. Geological Survey Open-File Report 2007–1244, 6 p. 
iii

Contents

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

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

Methods...........................................................................................................................................................1

Site Information.....................................................................................................................................1

Sample Analysis....................................................................................................................................2

Results .............................................................................................................................................................2

Streamflow, Escherichia coli, and Suspended Sediment..............................................................2

Berger Ditch Streamflow............................................................................................................2

Escherichia coli Concentrations and Discharges..................................................................2

Suspended-Sediment Concentrations and Discharges........................................................4

Correlation Analyses............................................................................................................................4

Acknowledgments.........................................................................................................................................6

References Cited............................................................................................................................................6

Figures

1–6. Graphs showing:

1. Instantaneous streamflow, Escherichia coli concentrations, and 

suspended-sediment concentrations near the mouth of Berger Ditch, 

Oregon, Ohio, July and August 2006.................................................................................3

2. Instantaneous streamflow and Escherichia coli concentrations 

near the mouth of Berger Ditch, Oregon, Ohio, July and August 2006 .......................3

3. Instantaneous discharges of Escherichia coli near the mouth of 

Berger Ditch, Oregon, Ohio, July 2006 .............................................................................4

4. Instantaneous streamflow and suspended-sediment concentrations near 

the mouth of Berger Ditch, Oregon, Ohio, July and August 2006 ................................5

5. Relation between Escherichia coli and streamflow 40 minutes prior to 

sampling in Berger Ditch, Oregon, Ohio, July 2006........................................................5

6. Relation between suspended sediment and streamflow in Berger Ditch, 

Oregon, Ohio, July–August 2006 .......................................................................................6
iv

Conversion Factors and Abbreviations

Multiply By To obtain

Length

foot (ft) 0.3048 meter (m)

Area

square mile (mi2

) 2.590 square kilometer (km2) 

Volume

cubic foot (ft3

) 0.02832 cubic meter (m3)

liter (L) 0.2642 gallon (gal)

cubic meter (m3

) 35.31 cubic foot (ft3)

Flow rate

cubic foot per second (ft3

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

Mass

kilogram (kg) 2.205 pound, avoirdupois (lb)

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

°F=(1.8×°C)+32

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

Concentrations of bacteria in water are given in colony-forming units per 100 milliliters 

(cfu/100 mL).

Instantaneous discharges are given in colony-forming units of Escherichia coli per second (cfu/s). 

Suspended-sediment discharges are given in kilograms per second (kg/s). 

Abbreviations

ADVM – acoustic Doppler velocity meter 

E. coli – Escherichia coli 

LEPF – Lake Erie Protection Fund 

MBSP – Maumee Bay State Park 

mg – milligram

mL – milliliter

NTU – Nephelometric Turbidity Units 

μm – micrometer

USGS – U.S. Geological Survey

UT – University of Toledo 
Abstract

Berger Ditch discharges to the marina at Maumee Bay 

State Park (MBSP), just east of the MBSP bathing beach. 

Recent studies by U.S. Geological Survey (USGS) and 

University of Toledo researchers have identified the ditch as 

a source of Escherichia coli (E. coli), an indicator bacterium 

that is used to assess recreational water quality. An automatic 

sampler was installed at a USGS streamgage on Berger Ditch. 

Samples were collected as a function of streamflow, including 

negative flow conditions. Instantaneous discharges of E. coli

and suspended sediment from Berger Ditch were calculated. 

When samples were collected, streamflow ranged from -21 

to 227 cubic feet per second (ft3/s) and over the entire time 

period, streamflow ranged from -23 to 243 ft3/s. Discharges 

of E. coli ranged from 2.5 × 108 to greater than 2.6 × 1010

colony-forming units per second (cfu/s), and suspended-sediment discharges ranged from 0.01 to 2.2 kilograms per second 

(kg/s). One sample was collected during negative flow conditions, and discharges of E. coli and suspended sediment in this 

sample were -4.3 × 108 cfu/s and -0.015 kg/s, respectively. 

Introduction

Maumee Bay, in the southwest corner of Lake Erie near 

Toledo and Oregon, Ohio, is a popular recreational destination for swimming and boating. Maumee Bay State Park 

(MBSP), an important tourist attraction in the area, has a 

Lake Erie shoreline beach and an inland beach. The Lake Erie 

beach nearshore area often has high Escherichia coli (E. coli) 

concentrations, indicating a potential health risk to beachgoers. Berger Ditch, which discharges into the marina just east of 

the Lake Erie beach, has been identified as a source of E. coli

(Glatzer and Erichsen, 2003; Francy and others, 2005). As 

suggested by these studies, the next step is to develop a better understanding of the influence of Berger Ditch on E. coli

concentrations at the MBSP beach. The U.S. Geological 

Survey (USGS), in cooperation with the University of Toledo 

(UT), undertook a project to examine the discharges of E. coli

and suspended sediment from Berger Ditch in relation to the 

concentrations of E. coli at the MBSP Lake Erie beach. The 

goal of this report is to summarize the results of actions taken 

that were funded by the Lake Erie Protection Fund (LEPF) 

Small Grant, primarily the instantaneous discharges of E. coli 

and suspended sediment from Berger Ditch as determined 

from samples collected by an automatic sampler installed at 

the USGS streamgage on the ditch. 

Methods

Site Information

Berger Ditch discharges into the marina at MBSP 230 ft 

east of the Lake Erie bathing beach. The ditch receives flow 

from Wolf Ditch, which drains approximately 10.7 mi2 and 

flows through Oregon and Jerusalem Township. The drainage area of Berger Ditch at its mouth is approximately 16 mi2

. 

Land use in the Berger Ditch drainage is primarily farmland 

with some single-family residences. Overland runoff and 

discharges from septic systems are the expected sources of 

contamination to the ditch.

Negative flows are frequently observed in Berger Ditch. 

These negative flows can be caused by localized northern 

winds that push water upstream into the ditch or by the Lake 

Erie seiche. A seiche is a standing wave in an enclosed body 

of water such as a lake, which can be caused by wind, storm 

events, or earthquakes. Due to the shallowness of Lake Erie, 

wind-caused seiches are common. 

To assist with understanding the hydrology in the ditch, 

including frequency and duration of negative flows, a USGS 

streamgage was installed on Berger Ditch in May 2006. An 

acoustic Doppler velocity meter (ADVM) was installed in 

the ditch to measure stream-velocity and calculate cross-sectional area (based on instantaneously measured water height 

and programmed cross-sectional elevations) at 10-minute 

intervals. The ADVM then calculates and records streamflow using standard USGS techniques (Rantz and others, 

1982). Funds provided by the LEPF Small Grant enabled 

real-time streamflow information for this site to be available 

online at http://waterdata.usgs.gov/oh/nwis/nwisman/?site_

no=04194085&agency_cd=USGS. 

Escherichia coli and Suspended Sediment in Berger Ditch 

at Maumee Bay State Park, Oregon, Ohio, 2006

By Amie M.G. Brady 
In June 2006, a refrigerated automatic sampler was installed 

and programmed to collect samples from the ditch when both 

of the following conditions exist: (1) there was a change in 

streamflow of 8 ft3/s or more over a 10-minute interval and 

(2) the flow was greater than 15 ft3/s or less than -15 ft3/s. 

Therefore, samples could be collected every 10 minutes if the 

conditions of the program were met. Because of some technical difficulties, the sampler was not completely ready for use 

until July 2006. These difficulties included problems with the 

sampler program and thunderstorms that delayed installation 

of the equipment required to transmit the data to the Internet 

which allowed the student to monitor when the sampler collected samples.

Sample Analysis

Samples collected by the automatic sampler were 

retrieved by a UT student within 24 hours of collection. Also, 

within 24 hours of sample collection, a UT student determined sample turbidity and filtered the sample to determine 

E. coli concentration. A portable turbidimeter (Hach, Loveland, Colo.) was used to determine turbidity, and results were 

reported in Nephelometric Turbidity Units (NTU). U.S. Environmental Protection Agency Method 1603 (2002) was used to 

determine E. coli concentrations. Briefly, a volume of sample 

water was filtered through a 0.45-μm-pore-size filter and 

then transferred to a modified mTEC agar plate. Plates were 

incubated at 35°C for 2 hours and then at 44.5°C for 22 to 

24 hours. Colonies that appear magenta in color were counted 

as E. coli. Results were reported in colony-forming units per 

100 milliliters (cfu/100 mL). 

Suspended-sediment analyses were done by Heidelberg 

College, Tiffin, Ohio. After removing an aliquot to obtain 

E. coli concentrations and turbidity, the sample bottles (with 

the remaining sample volume) were stored in a cool, dark 

location until USGS personnel could retrieve and deliver the 

bottles to Heidelberg College. Concentrations of suspended 

sediment were determined by means of the filtration method 

as described in Guy (1969) and reported in milligrams per liter 

(mg/L).

To represent the magnitude of E. coli and suspended-sediment transport in the ditch at the time of sampling, instantaneous discharges were computed as follows:

E. coli concentration (cfu/100 mL) × (106

 mL / 1 m3) × 

(1 m3 / 35.31 ft3) × streamflow (ft3/s)

to obtain instantaneous discharges with the units of colonyforming units of E. coli per second (cfu/s), and

suspended-sediment concentration (mg/L) × 

(28.32 L / 1 ft3

) × (1 kg / 106 mg) × streamflow (ft3/s)

to obtain instantaneous discharges with the units of kilograms 

per second (kg/s).

Results

A total of 107 samples were collected from the autosampler and analyzed. Forty-one samples were analyzed for both 

E. coli and suspended-sediment concentrations. Forty-two 

samples were analyzed for E. coli concentrations only, and 

24 samples were analyzed for suspended-sediment concentrations only. This discrepancy in sample analyses was a result 

of miscommunication between the USGS and UT scientists. 

Future studies will be more closely monitored to minimize 

similar communication problems. Other samples were collected by the sampler but were not analyzed because they 

were not retrieved within the 24-hour holding time for E. coli

analysis as required for this project or they were retrieved, but 

not saved for suspended-sediment analysis.

Streamflow, Escherichia coli, and Suspended 

Sediment

Samples were collected over a range of streamflows 

(fig. 1). The data will be discussed further in the next few 

paragraphs. It is worth noting that samples were collected and 

analyzed for both E. coli and suspended-sediment concentrations during two high-flow events as can be seen in figure 1. 

Also, only one sample was collected during negative flow 

conditions, and the results are indicated on the figure. 

Berger Ditch Streamflow

Instantaneous streamflow during July and August ranged 

from -23 to 243 ft3/s. Daily mean streamflow ranged from 

-0.15 to 155 ft3/s, with a median of 1.75 ft3/s. Of the measurements made at the USGS streamgage during this time 

(n = 8,928), 25 percent of the measurements were recorded as 

negative flows. The largest magnitude of negative flow was 

-23 ft3/s measured on July 3, 2006. For samples analyzed for 

E. coli concentrations, the instantaneous streamflow at time of 

collection ranged from -21 to 227 ft3

/s, with a median of 

35 ft3/s. For samples analyzed for suspended-sediment concentrations, instantaneous streamflow ranged from -21 to 

118 ft3/s, with a median of 35 ft3/s.

Escherichia coli Concentrations and Discharges

Samples that were analyzed for E. coli were collected 

during July 2006 (fig. 2). Of the 83 samples analyzed 

for E. coli concentrations, 30 samples, representing two 

precipitation events, were too numerous to count (estimated 

concentrations were greater than 2,700 or greater than 

8,000 cfu/100 mL). Unfortunately, these samples were 

collected during the peak streamflow for the precipitation 

events. Because results for these samples were estimated 

values, they were not included in analyses. The bulk of the 

samples used in data analysis were collected following peak 

streamflow for the events sampled. 

2 Escherichia coli and Suspended Sediment in Berger Ditch at Maumee Bay State Park, Oregon, Ohio, 2006
Figure 1. Instantaneous streamflow, Escherichia coli concentrations, and suspended-sediment concentrations near the mouth of 

Berger Ditch, Oregon, Ohio, July and August 2006. The sample collected during negative flow is indicated by the enlarged red symbols. 

Figure 2. Instantaneous streamflow and Escherichia coli concentrations near the mouth of Berger Ditch, Oregon, Ohio, July and 

August 2006. 

Results 3

1 0 2

1 0 3

1 0 4

1 0 5

-5 0

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

Ju ly 1 , 2 0 0 6 Ju ly 1 5 , 2 0 0 6 A u g u s t 1 , 2 0 0 6 A u g u s t 1 5 , 2 0 0 6 A u g u s t 3 1 , 2 0 0 6

0

2 0 0

4 0 0

6 0 0

8 0 0

STREAMFLOW, IN CUBIC 

FEET PER SECOND

SUSPENDED SEDIMENT, 

IN MILLIGRAMS PER LITER

ESCHERICHIA COLI, IN COLONY-FORMING UNITS PER 100 MILLILITERS

-5 0

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

7 /1 /2 0 0 6 7 /8 /2 0 0 6 7 /1 6 /2 0 0 6 7 /2 3 /2 0 0 6 7 /3 1 /2 0 0 6

1 0 2

1 0 3

1 0 4

1 0 5

STREAMFLOW, IN CUBIC FEET PER SECOND

DATE

ESCHERICHIA COLI, IN COLONY-FORMING UNITS PER 100 MILLILITERS
Concentrations (within countable limits) of E. coli

in samples ranged from 480 to 12,000 cfu/100 mL, with a 

median of 2,400 cfu/100 mL. Discharges of E. coli when flow 

was positive ranged from 2.5 × 108 to 2.4 × 1010 cfu/s, with 

a median of 2.0 × 109 cfu/s. For the single sample collected 

when flow was negative (-21 ft3/s), the discharge of E. coli was 

-4.3 × 108 cfu/s. In the boxplot of the data (fig. 3), the negative-flow sample is shown as a single point. 

Suspended-Sediment Concentrations and 

Discharges

Samples analyzed for suspended-sediment concentrations 

were collected during July and August (fig. 4). Suspendedsediment concentrations ranged from 24 to 720 mg/L, with a 

median value of 130 mg/L. Discharges of suspended sediment 

when flow was positive ranged from 0.01 to 2.2 kg/s, with a 

median of 0.15 kg/s. For the sample collected during negative 

flow, the associated discharge was -0.015 kg/s.

Correlation Analyses

Correlation analysis and scatterplots were used to examine the relations between E. coli and suspended-sediment 

concentrations and discharges. Pearson’s r is a correlation 

coefficient that measures the linear association between two 

variables. The more the correlation coefficient differs from 1 

or -1 and approaches zero, the weaker the relation. The level 

of significance was set at α = 0.05 for this report.

E. coli concentrations were significantly related to both 

turbidity and suspended-sediment concentrations (r = 0.42 

and r = 0.73, respectively). However, E. coli concentrations 

were not related to streamflow in the ditch at time of sampling. 

E. coli concentrations tended to increase after streamflow 

increased. Based on analyses, the highest correlations were 

observed between E. coli concentrations and streamflow 

40 minutes prior to sampling (log10-transformed values) 

(fig. 5). As expected, concentrations of suspended sediment 

were significantly related to turbidity (r = 0.98). Suspendedsediment concentrations were also significantly related to 

streamflow (fig. 6).

Figure 3. Instantaneous discharges of Escherichia coli near the mouth of Berger Ditch, Oregon, Ohio, July 2006. One sample was 

collected during negative flow, and the magnitude of discharge associated with that sample is indicated by the diamond. 

4 Escherichia coli and Suspended Sediment in Berger Ditch at Maumee Bay State Park, Oregon, Ohio, 2006

1 0 8

1 0 9

1 0 10

1 0 11

outlier2

upper whisker1

negative flow

data point

7 5 th percentile

m edian

2 5 th percentile

lower whisker1

E XPLANATION

1

The span of the whiskers is

the largest and smallest values

within 1.5 times the interquartile

range

2

Outliers are defined as

values outside of the whisker

span

INSTANTANEOUS DISCHARGE OF ESCHERICHIA COLI, IN COLONY-FORMING UNITS PER SECOND
Figure 4. Instantaneous streamflow and suspended-sediment concentrations near the mouth of Berger Ditch, Oregon, Ohio, July and 

August 2006. 

Figure 5. Relation between Escherichia coli and streamflow 40 minutes prior to sampling in Berger Ditch, Oregon, Ohio, July 2006. The 

line is the linear-fit line. [r, Pearson’s correlation coefficient; p, significance of the relation.] 

Results 5

-5 0

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

7 /4 /2 0 0 6 7 /1 8 /2 0 0 6 8 /1 /2 0 0 6 8 /1 5 /2 0 0 6 8 /3 0 /2 0 0 6

-2 0 0

0

2 0 0

4 0 0

6 0 0

8 0 0

STREAMFLOW, IN CUBIC FEET PER SECOND

DATE

SUSPENDED SEDIMENT, IN MILLIGRAMS PER LITER

1 0 0 1 0 1 1 0 2 1 0 2

1 0 3

1 0 4

1 0 5

r = 0 .4 5

p = 0 .0 0 0 8

ESCHERICHIA COLI, IN COLONY-FORMING UNITS PER 100 MILLILITERS

STREAMFLOW, IN CUBIC FEET PER SECOND
Acknowledgments

Colin DeSaint Victor, Pamela Struffolino, and Jona 

Scarboro of the University of Toledo are thanked for their 

assistance with project planning and sample collection and 

analysis. Daryl Dwyer of the University of Toledo is thanked 

for his assistance in the planning and implementation of this 

project. Project-related financial assistance was provided to 

the University of Toledo by U.S. Department of Agriculture 

Grant OHOW-2005-06225.

References Cited

Francy, D.S., Struffolino, P., Brady, A.M.G., and Dwyer, 

D.F., 2005, A spatial multivariable approach for identifying proximate sources of Escherichia coli to Maumee Bay, 

Lake Erie, Ohio: U.S. Geological Survey Open-File Report 

2005–1386, 20 p.

Glatzer, L., and Erichsen K., 2003, Wolf Creek bacterial 

impacts on Maumee Bay State Park Beach, summary report: 

Bowling Green, Ohio, Maumee RAP Publications, 10 p., 

accessed July 2007 at http://www.epa.state.oh.us/dsw/rap/

WolfCreekSummary.pdf

Guy, H.P., 1969, Laboratory theory and methods for sediment 

analysis: U.S. Geological Survey Techniques of WaterResources Investigations, book 5, chap. C1, 58 p.

Rantz, S.E., and others, 1982, Measurement and computation 

of streamflow; Volume 1, Measurement of stage and streamflow: U.S. Geological Survey Water-Supply Paper 2175, 

v. 1, 284 p.

U.S. Environmental Protection Agency, 2002, Method 

1603—Escherichia coli in water by membrane filtration 

using modified membrane-thermotolerant Escherichia coli

agar: Washington, D.C., EPA 821-R-02-23, 9 p. 

Figure 6. Relation between suspended sediment and streamflow in Berger Ditch, Oregon, Ohio, July–August 2006. The line is the 

linear-fit line. [r, Pearson’s correlation coefficient; p, significance of the relation; <, less than] 

6 Escherichia coli and Suspended Sediment in Berger Ditch at Maumee Bay State Park, Oregon, Ohio, 2006

0 2 5 5 0 7 5 1 0 0 1 2 5 1 5 0

0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

7 0 0

8 0 0

r = 0 .6 3

p < 0 .0 0 0 1

STREAMFLOW, IN CUBIC FEET PER SECOND

SUSPENDED SEDIMENT, IN MILLIGRAMS PER LITER

Brady—Escherichia coli and Suspended Sediment in Berger Ditch at Maumee Bay State Park, Oregon, Ohio, 2006—Open-File Report 2007–1244